Diagnostic flags in Clang¶

Introduction ¶

Diagnostic text:

warning: ‘NSObject’ attribute may be put on a typedef only; attribute is ignored

-Wabi ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wabsolute-value ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: absolute value function A given an argument of type B but has parameter of type C which may cause truncation of value

warning: taking the absolute value of

pointer

function

array

type B is suspicious

warning: taking the absolute value of unsigned type A has no effect

warning: using

integer

floating point

complex

absolute value function A when argument is of

integer

floating point

complex

type

-Wabstract-final-class ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: abstract class is marked ‘

final

sealed

‘

-Wabstract-vbase-init ¶

Diagnostic text:

warning: initializer for virtual base class A of abstract class B will never be used

-Waddress ¶

This diagnostic is enabled by default.

Controls -Wpointer-bool-conversion, -Wstring-compare, -Wtautological-pointer-compare.

-Waddress-of-packed-member ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: taking address of packed member A of class or structure B may result in an unaligned pointer value

-Waddress-of-temporary ¶

This diagnostic is an error by default, but the flag -Wno-address-of-temporary can be used to disable the error.

Diagnostic text:

error: taking the address of a temporary object of type A

-Waggregate-return ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Waix-compat ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: alignment of 16 bytes for a struct member is not binary compatible with IBM XL C/C++ for AIX 16.1.0 or older

warning: #pragma align(packed) may not be compatible with objects generated with AIX XL C/C++

-Walign-mismatch ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: passing A-byte aligned argument to B-byte aligned parameter C

of E

may result in an unaligned pointer access

-Wall ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wmisleading-indentation, -Wmost, -Wpacked-non-pod, -Wparentheses, -Wswitch, -Wswitch-bool.

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘…’ in this location creates a C-style varargs function

, not a function parameter pack

-Wambiguous-macro ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ambiguous expansion of macro A

-Wambiguous-member-template ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: lookup of A in member access expression is ambiguous; using member of B

-Wambiguous-reversed-operator ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ISO C++20 considers use of overloaded operator ‘A’ (with operand types B and C) to be ambiguous despite there being a unique best viable function

with non-reversed arguments

-Wanalyzer-incompatible-plugin ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: checker plugin ‘A’ is not compatible with this version of the analyzer

-Wanon-enum-enum-conversion ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wdeprecated-anon-enum-enum-conversion.

Diagnostic text:

warning:

arithmetic between

bitwise operation between

comparison of

conditional expression between

compound assignment of

different enumeration types

(B and C)

-Wanonymous-pack-parens ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ISO C++11 requires a parenthesized pack declaration to have a name

-Warc ¶

This diagnostic is enabled by default.

Controls -Warc-non-pod-memaccess, -Warc-retain-cycles, -Warc-unsafe-retained-assign.

-Warc-bridge-casts-disallowed-in-nonarc ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘A’ casts have no effect when not using ARC

-Warc-maybe-repeated-use-of-weak ¶

Diagnostic text:

warning: weak

variable

property

implicit property

instance variable

B may be accessed multiple times in this

function

method

block

lambda

and may be unpredictably set to nil; assign to a strong variable to keep the object alive

-Warc-non-pod-memaccess ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

destination for

source of

this B call is a pointer to ownership-qualified type C

-Warc-performSelector-leaks ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: performSelector may cause a leak because its selector is unknown

-Warc-repeated-use-of-weak ¶

Also controls -Warc-maybe-repeated-use-of-weak.

Diagnostic text:

warning: weak

variable

property

implicit property

instance variable

B is accessed multiple times in this

function

method

block

lambda

but may be unpredictably set to nil; assign to a strong variable to keep the object alive

-Warc-retain-cycles ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: capturing A strongly in this block is likely to lead to a retain cycle

-Warc-unsafe-retained-assign ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: assigning

array literal

dictionary literal

numeric literal

boxed expression

block literal

to a weak

property

variable

; object will be released after assignment

warning: assigning retained object to

weak

unsafe_unretained

property

variable

; object will be released after assignment

warning: assigning retained object to unsafe property; object will be released after assignment

-Wargument-outside-range ¶

This diagnostic is an error by default, but the flag -Wno-argument-outside-range can be used to disable the error.

Diagnostic text:

error: argument value A is outside the valid range [B, C]

-Wargument-undefined-behaviour ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: argument value A will result in undefined behaviour

-Warray-bounds ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: array index A is past the end of the array (that has type B

, cast to D

)

warning: array index A refers past the last possible element for an array in B-bit address space containing C-bit (D-byte) elements (max possible E element

)

warning: array index A is before the beginning of the array

warning: the pointer incremented by A refers past the last possible element for an array in B-bit address space containing C-bit (D-byte) elements (max possible E element

)

warning: array argument is too small;

contains A elements

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Watimport-in-framework-header ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: use of ‘@import’ in framework header is discouraged, including this header requires -fmodules

-Watomic-access ¶

This diagnostic is an error by default, but the flag -Wno-atomic-access can be used to disable the error.

Diagnostic text:

error: accessing a member of an atomic structure or union is undefined behavior

-Watomic-alignment ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: misaligned atomic operation may incur significant performance penalty; the expected alignment (A bytes) exceeds the actual alignment (B bytes)

warning: large atomic operation may incur significant performance penalty; the access size (A bytes) exceeds the max lock-free size (B bytes)

-Watomic-implicit-seq-cst ¶

Diagnostic text:

warning: implicit use of sequentially-consistent atomic may incur stronger memory barriers than necessary

-Watomic-memory-ordering ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: memory order argument to atomic operation is invalid

-Watomic-properties ¶

Controls -Wcustom-atomic-properties, -Wimplicit-atomic-properties.

-Watomic-property-with-user-defined-accessor ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: writable atomic property A cannot pair a synthesized

getter

setter

with a user defined

getter

setter

-Wattribute-packed-for-bitfield ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘packed’ attribute was ignored on bit-fields with single-byte alignment in older versions of GCC and Clang

-Wattribute-warning ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: call to ‘A’ declared with ‘warning’ attribute: B

-Wattributes ¶

This diagnostic is enabled by default.

Controls -Wignored-attributes, -Wunknown-attributes.

-Wauto-disable-vptr-sanitizer ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: implicitly disabling vptr sanitizer because rtti wasn’t enabled

-Wauto-import ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wauto-storage-class ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘auto’ storage class specifier is not permitted in C++11, and will not be supported in future releases

-Wauto-var-id ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘auto’ deduced as ‘id’ in declaration of A

-Wavailability ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘unavailable’ availability overrides all other availability information

warning: Fuchsia API Level prohibits specifying a minor or sub-minor version

warning: ignoring availability attribute

on ‘+load’ method

with constructor attribute

with destructor attribute

warning: only ‘unavailable’ and ‘deprecated’ are supported for Swift availability

warning: unknown platform A in availability macro

warning: feature cannot be

introduced

deprecated

obsoleted

in B version C before it was

introduced

deprecated

obsoleted

in version E; attribute ignored

warning: use same version number separators ‘_’ or ‘.’; as in ‘major[.minor[.subminor]]’

warning: availability does not match previous declaration

warning:

overriding

method

introduced after

deprecated before

obsoleted before

the protocol method it implements

overridden method

on B (C vs. D)

warning:

overriding

method cannot be unavailable on A when

the protocol method it implements

its overridden method

is available

-Wavr-rtlib-linking-quirks ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: support for linking stdlibs for microcontroller ‘A’ is not implemented

warning: no avr-libc installation can be found on the system, cannot link standard libraries

warning: support for passing the data section address to the linker for microcontroller ‘A’ is not implemented

warning: no target microcontroller specified on command line, cannot link standard libraries, please pass -mmcu=<mcu name>

warning: standard library not linked and so no interrupt vector table or compiler runtime routines will be linked

-Wbackend-plugin ¶

This diagnostic is enabled by default.

Diagnostic text:

The text of this diagnostic is not controlled by Clang.

warning: A (B) exceeds limit (C) in ‘D’

-Wbackslash-newline-escape ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: backslash and newline separated by space

-Wbad-function-cast ¶

Diagnostic text:

warning: cast from function call of type A to non-matching type B

-Wbinary-literal ¶

Controls -Wc++14-binary-literal, -Wc++98-c++11-compat-binary-literal, -Wgnu-binary-literal.

-Wbind-to-temporary-copy ¶

Also controls -Wc++98-compat-bind-to-temporary-copy.

Diagnostic text:

warning: C++98 requires an accessible copy constructor for class C when binding a reference to a temporary; was

private

protected

warning: no viable constructor

copying variable

copying parameter

initializing template parameter

returning object

initializing statement expression result

throwing object

copying member subobject

copying array element

allocating object

This diagnostic is enabled by default.

Diagnostic text:

warning: operator ‘?:’ has lower precedence than ‘A’; ‘A’ will be evaluated first

-Wbitwise-instead-of-logical ¶

Diagnostic text:

warning: use of bitwise ‘A’ with boolean operands

-Wbitwise-op-parentheses ¶

Diagnostic text:

warning: ‘A’ within ‘B’

-Wblock-capture-autoreleasing ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: block captures an autoreleasing out-parameter, which may result in use-after-free bugs

-Wbool-conversion ¶

This diagnostic is enabled by default.

Also controls -Wpointer-bool-conversion, -Wundefined-bool-conversion.

Diagnostic text:

warning: initialization of pointer of type A to null from a constant boolean expression

-Wbool-operation ¶

Also controls -Wbitwise-instead-of-logical.

Diagnostic text:

warning: bitwise negation of a boolean expression

;

always evaluates to ‘true’;

did you mean logical negation?

-Wbraced-scalar-init ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: braces around

scalar

initializer

-Wbranch-protection ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘-mbranch-protection=’ option is incompatible with the ‘A’ architecture

warning: ignoring the ‘branch-protection’ attribute because the ‘A’ architecture does not support it

warning: invalid branch protection option ‘A’ in ‘B’

warning: unsupported branch protection specification ‘A’

-Wbridge-cast ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: A bridges to B, not C

warning: A cannot bridge to B

-Wbuiltin-assume-aligned-alignment ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: requested alignment must be A bytes or smaller; maximum alignment assumed

-Wbuiltin-macro-redefined ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: redefining builtin macro

warning: undefining builtin macro

-Wbuiltin-memcpy-chk-size ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘A’ will always overflow; destination buffer has size B, but size argument is C

-Wbuiltin-requires-header ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: declaration of built-in function ‘B’ requires inclusion of the header <A>

-Wc++-compat ¶

Diagnostic text:

warning:

empty

struct

union

has size 0 in C,

size 1

non-zero size

in C++

-Wc++11-compat ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wc++11-compat-deprecated-writable-strings, -Wc++11-compat-reserved-user-defined-literal, -Wc++11-narrowing, -Wpre-c++14-compat, -Wpre-c++17-compat, -Wpre-c++20-compat, -Wpre-c++23-compat.

Diagnostic text:

warning: integer literal is too large to be represented in type ‘long’ and is subject to undefined behavior under C++98, interpreting as ‘unsigned long’; this literal will

have type ‘long long’

be ill-formed

in C++11 onwards

warning: ‘auto’ storage class specifier is redundant and incompatible with C++11

warning: identifier after literal will be treated as a user-defined literal suffix in C++11

warning: ‘A’ is a keyword in C++11

warning: use of right-shift operator (‘>>’) in template argument will require parentheses in C++11

warning: explicit instantiation cannot be ‘inline’

warning: explicit instantiation of A must occur at global scope

warning: explicit instantiation of A not in a namespace enclosing B

warning: explicit instantiation of A must occur in namespace B

warning: integer literal is too large to be represented in type ‘long’, interpreting as ‘unsigned long’ per C++98; this literal will

have type ‘long long’

be ill-formed

in C++11 onwards

-Wc++11-compat-deprecated-writable-strings ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: conversion from string literal to A is deprecated

-Wc++11-compat-pedantic ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wc++11-compat, -Wpre-c++14-compat-pedantic, -Wpre-c++17-compat-pedantic, -Wpre-c++20-compat-pedantic, -Wpre-c++23-compat-pedantic.

-Wc++11-compat-reserved-user-defined-literal ¶

Diagnostic text:

warning: identifier after literal will be treated as a reserved user-defined literal suffix in C++11

-Wc++11-extensions ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wc++11-extra-semi, -Wc++11-inline-namespace, -Wc++11-long-long.

Diagnostic text:

warning: alias declarations are a C++11 extension

warning: implicit conversion from array size expression of type A to

integral

enumeration

type C is a C++11 extension

warning: ‘auto’ type specifier is a C++11 extension

warning: enumeration types with a fixed underlying type are a C++11 extension

warning:

defaulted

deleted

function definitions are a C++11 extension

warning: befriending enumeration type A is a C++11 extension

warning: commas at the end of enumerator lists are a C++11 extension

warning: explicit conversion functions are a C++11 extension

warning: extern templates are a C++11 extension

warning: range-based for loop is a C++11 extension

warning: generalized initializer lists are a C++11 extension

warning: use of enumeration in a nested name specifier is a C++11 extension

warning: non-class friend type A is a C++11 extension

warning: default member initializer for non-static data member is a C++11 extension

warning: ‘A’ keyword is a C++11 extension

warning: reference qualifiers on functions are a C++11 extension

warning: rvalue references are a C++11 extension

warning: scoped enumerations are a C++11 extension

warning: static data member A in union is a C++11 extension

warning: non-type template argument referring to

function

object

B with internal linkage is a C++11 extension

warning: ‘template’ keyword outside of a template

warning: default template arguments for a function template are a C++11 extension

warning: ‘typename’ occurs outside of a template

warning: unelaborated friend declaration is a C++11 extension; specify ‘

struct

interface

union

class

enum

‘ to befriend B

warning: variadic templates are a C++11 extension

warning: [[]] attributes are a C++11 extension

-Wc++11-extra-semi ¶

Diagnostic text:

warning: extra ‘;’ outside of a function is a C++11 extension

-Wc++11-inline-namespace ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: inline namespaces are a C++11 feature

-Wc++11-long-long ¶

Diagnostic text:

warning: ‘long long’ is a C++11 extension

-Wc++11-narrowing ¶

Some of the diagnostics controlled by this flag are enabled by default.

Diagnostic text:

error:

case value

enumerator value

non-type template argument

array size

explicit specifier argument

noexcept specifier argument

cannot be narrowed from type C to D

evaluates to C, which cannot be narrowed to type D

error: constant expression evaluates to A which cannot be narrowed to type B

error: type A cannot be narrowed to B in initializer list

error: non-constant-expression cannot be narrowed from type A to B in initializer list

warning: constant expression evaluates to A which cannot be narrowed to type B in C++11

warning: type A cannot be narrowed to B in initializer list in C++11

warning: non-constant-expression cannot be narrowed from type A to B in initializer list in C++11

-Wc++14-attribute-extensions ¶

Diagnostic text:

warning: use of the A attribute is a C++14 extension

-Wc++14-binary-literal ¶

Diagnostic text:

warning: binary integer literals are a C++14 extension

-Wc++14-compat ¶

Controls -Wpre-c++17-compat, -Wpre-c++20-compat, -Wpre-c++23-compat.

-Wc++14-compat-pedantic ¶

Controls -Wc++14-compat, -Wpre-c++17-compat-pedantic, -Wpre-c++20-compat-pedantic, -Wpre-c++23-compat-pedantic.

-Wc++14-extensions ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wc++14-attribute-extensions, -Wc++14-binary-literal.

Diagnostic text:

warning: use of this statement in a constexpr

function

constructor

is a C++14 extension

warning: multiple return statements in constexpr function is a C++14 extension

warning: variable declaration in a constexpr

function

constructor

is a C++14 extension

warning: type definition in a constexpr

function

constructor

is a C++14 extension

warning: ‘decltype(auto)’ type specifier is a C++14 extension

warning: initialized lambda captures are a C++14 extension

warning: variable templates are a C++14 extension

-Wc++17-attribute-extensions ¶

Diagnostic text:

warning: use of the A attribute is a C++17 extension

-Wc++17-compat ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wc++17-compat-mangling, -Wdeprecated-increment-bool, -Wdeprecated-register, -Wpre-c++20-compat, -Wpre-c++23-compat.

-Wc++17-compat-mangling ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: mangled name of A will change in C++17 due to non-throwing exception specification in function signature

-Wc++17-compat-pedantic ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wc++17-compat, -Wpre-c++20-compat-pedantic, -Wpre-c++23-compat-pedantic.

-Wc++17-extensions ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wc++17-attribute-extensions.

Diagnostic text:

warning: ISO C++ standards before C++17 do not allow new expression for type A to use list-initialization

warning: constexpr if is a C++17 extension

warning: ‘constexpr’ on lambda expressions is a C++17 extension

warning: ‘static_assert’ with no message is a C++17 extension

warning: decomposition declarations are a C++17 extension

warning: pack fold expression is a C++17 extension

warning: ‘begin’ and ‘end’ returning different types (A and B) is a C++17 extension

warning: hexadecimal floating literals are a C++17 feature

warning: ‘

switch

‘ initialization statements are a C++17 extension

warning: inline variables are a C++17 extension

warning: use of multiple declarators in a single using declaration is a C++17 extension

warning: nested namespace definition is a C++17 extension; define each namespace separately

warning: attributes on

a namespace

an enumerator

declaration are a C++17 extension

warning: capture of ‘*this’ by copy is a C++17 extension

warning: template template parameter using ‘typename’ is a C++17 extension

warning: default scope specifier for attributes is a C++17 extension

warning: pack expansion of using declaration is a C++17 extension

-Wc++20-attribute-extensions ¶

Diagnostic text:

warning: use of the A attribute is a C++20 extension

-Wc++20-compat ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wpre-c++23-compat.

Diagnostic text:

warning: use of implicit ‘typename’ is incompatible with C++ standards before C++20

warning: aggregate initialization of type A with user-declared constructors is incompatible with C++20

warning: ‘consteval’ specifier is incompatible with C++ standards before C++20

warning: ‘constinit’ specifier is incompatible with C++ standards before C++20

warning: this expression will be parsed as explicit(bool) in C++20

warning: ‘<=>’ is a single token in C++20; add a space to avoid a change in behavior

warning: taking address of non-addressable standard library function is incompatible with C++20

warning: type of UTF-8 string literal will change from array of const char to array of const char8_t in C++20

warning: ‘A’ is a keyword in C++20

-Wc++20-compat-pedantic ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wc++20-compat, -Wpre-c++23-compat-pedantic.

-Wc++20-designator ¶

Diagnostic text:

warning: designated initializers are a C++20 extension

-Wc++20-extensions ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wc++20-attribute-extensions, -Wc++20-designator.

Diagnostic text:

warning: use of function template name with no prior declaration in function call with explicit template arguments is a C++20 extension

warning: default member initializer for bit-field is a C++20 extension

warning: captured structured bindings are a C++20 extension

warning: use of this statement in a constexpr

function

constructor

is a C++20 extension

warning: constexpr constructor that does not initialize all members is a C++20 extension

warning: function try block in constexpr

function

constructor

is a C++20 extension

warning: uninitialized variable in a constexpr

function

constructor

is a C++20 extension

warning: constexpr union constructor that does not initialize any member is a C++20 extension

warning: decomposition declaration declared

‘B’

with ‘B’ specifiers

is a C++20 extension

warning: defaulted comparison operators are a C++20 extension

warning: explicit capture of ‘this’ with a capture default of ‘=’ is a C++20 extension

warning: explicit(bool) is a C++20 extension

warning: range-based for loop initialization statements are a C++20 extension

warning: missing ‘typename’ prior to dependent type name AB; implicit ‘typename’ is a C++20 extension

warning: initialized lambda pack captures are a C++20 extension

warning: inline nested namespace definition is a C++20 extension

warning: explicit template parameter list for lambdas is a C++20 extension

warning: invoking a pointer to a ‘const &’ member function on an rvalue is a C++20 extension

warning: using declaration naming a scoped enumerator is a C++20 extension

warning: using enum declaration is a C++20 extension

warning: aggregate initialization of type A from a parenthesized list of values is a C++20 extension

-Wc++23-default-comp-relaxed-constexpr ¶

Diagnostic text:

warning: defaulted definition of

<ERROR>

equality

three-way

equality

relational

comparison operator

three-way comparison operator

that is declared

constexpr

consteval

but

for which the corresponding implicit ‘operator==’

invokes a non-constexpr comparison function is a C++23 extension

-Wc++23-extensions ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: static lambdas are a C++23 extension

warning: alias declaration in this context is a C++23 extension

warning: consteval if is a C++23 extension

warning: use of this statement in a constexpr

function

constructor

is a C++23 extension

warning: definition of a

static

thread_local

variable in a constexpr

function

constructor

is a C++23 extension

warning: use of a ‘#

elifdef

elifndef

‘ directive is a C++23 extension

warning: ‘size_t’ suffix for literals is a C++23 extension

warning: label at end of compound statement is a C++23 extension

warning:

an attribute specifier sequence

in this position is a C++23 extension

warning: lambda without a parameter clause is a C++23 extension

warning: declaring overloaded A as ‘static’ is a C++23 extension

-Wc++26-extensions ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wc++98-c++11-compat-binary-literal ¶

Diagnostic text:

warning: binary integer literals are incompatible with C++ standards before C++14

-Wc++98-c++11-compat-pedantic ¶

Synonym for -Wpre-c++14-compat-pedantic.

-Wc++98-compat ¶

Also controls -Wc++98-compat-local-type-template-args, -Wc++98-compat-unnamed-type-template-args, -Wpre-c++14-compat, -Wpre-c++17-compat, -Wpre-c++20-compat, -Wpre-c++23-compat.

Diagnostic text:

warning: alias declarations are incompatible with C++98

warning: ‘alignas’ is incompatible with C++98

warning: alignof expressions are incompatible with C++98

warning: [[]] attributes are incompatible with C++ standards before C++11

warning: ‘auto’ type specifier is incompatible with C++98

warning: ‘constexpr’ specifier is incompatible with C++98

warning: constructor call from initializer list is incompatible with C++98

warning: ‘decltype’ type specifier is incompatible with C++98

warning:

defaulted

deleted

function definitions are incompatible with C++98

warning: delegating constructors are incompatible with C++98

warning: scalar initialized from empty initializer list is incompatible with C++98

warning: initializing A from an empty initializer list is incompatible with C++98

warning: enumeration types with a fixed underlying type are incompatible with C++98

warning: befriending enumeration type A is incompatible with C++98

warning: enumeration type in nested name specifier is incompatible with C++98

warning: explicit conversion functions are incompatible with C++98

warning: range-based for loop is incompatible with C++98

warning: friend declaration naming a member of the declaring class is incompatible with C++98

warning: generalized initializer lists are incompatible with C++98

warning: jump from this goto statement to its label is incompatible with C++98

warning: jump from this

indirect

asm

goto statement to one of its possible targets is incompatible with C++98

warning: initialization of initializer_list object is incompatible with C++98

warning: inline namespaces are incompatible with C++98

warning: lambda expressions are incompatible with C++98

warning: ‘<::’ is treated as digraph ‘<:’ (aka ‘[’) followed by ‘:’ in C++98

warning: literal operators are incompatible with C++98

warning: universal character name referring to a control character is incompatible with C++98

warning: specifying character ‘A’ with a universal character name is incompatible with C++98

warning: noexcept specifications are incompatible with C++98

warning: noexcept expressions are incompatible with C++98

warning: use of non-static data member A in an unevaluated context is incompatible with C++98

warning: non-class friend type A is incompatible with C++98

warning: default member initializer for non-static data members is incompatible with C++98

warning:

anonymous struct

union

member B with a non-trivial

default constructor

copy constructor

move constructor

copy assignment operator

move assignment operator

destructor

is incompatible with C++98

warning: ‘nullptr’ is incompatible with C++98

warning: ‘A’ keyword is incompatible with C++98

warning: passing object of trivial but non-POD type A through variadic

function

block

method

constructor

is incompatible with C++98

warning: raw string literals are incompatible with C++98

warning: reference qualifiers on functions are incompatible with C++98

warning: reference initialized from initializer list is incompatible with C++98

warning: rvalue references are incompatible with C++98

warning: scoped enumerations are incompatible with C++98

warning: substitution failure due to access control is incompatible with C++98

warning: ‘static_assert’ declarations are incompatible with C++98

warning: static data member A in union is incompatible with C++98

warning: jump from switch statement to this case label is incompatible with C++98

warning: redundant parentheses surrounding address non-type template argument are incompatible with C++98

warning: use of null pointer as non-type template argument is incompatible with C++98

warning: non-type template argument referring to

function

object

B with internal linkage is incompatible with C++98

warning: use of ‘template’ keyword outside of a template is incompatible with C++98

warning: default template arguments for a function template are incompatible with C++98

warning: trailing return types are incompatible with C++98

warning: consecutive right angle brackets are incompatible with C++98 (use ‘> >’)

warning: use of ‘typename’ outside of a template is incompatible with C++98

warning: befriending B without ‘

struct

interface

union

class

enum

‘ keyword is incompatible with C++98

warning: unicode literals are incompatible with C++98

warning: ‘A’ type specifier is incompatible with C++98

warning: inheriting constructors are incompatible with C++98

warning: variadic templates are incompatible with C++98

-Wc++98-compat-bind-to-temporary-copy ¶

Diagnostic text:

warning:

copying variable

copying parameter

initializing template parameter

returning object

initializing statement expression result

throwing object

copying member subobject

copying array element

allocating object

copying temporary

initializing base subobject

initializing vector element

capturing value

of type C when binding a reference to a temporary would

invoke an inaccessible constructor

find no viable constructor

find ambiguous constructors

invoke a deleted constructor

in C++98

-Wc++98-compat-extra-semi ¶

Diagnostic text:

warning: extra ‘;’ outside of a function is incompatible with C++98

-Wc++98-compat-local-type-template-args ¶

Diagnostic text:

warning: local type A as template argument is incompatible with C++98

-Wc++98-compat-pedantic ¶

Also controls -Wc++98-compat, -Wc++98-compat-bind-to-temporary-copy, -Wc++98-compat-extra-semi, -Wpre-c++14-compat-pedantic, -Wpre-c++17-compat-pedantic, -Wpre-c++20-compat-pedantic, -Wpre-c++23-compat-pedantic.

Diagnostic text:

warning: implicit conversion from array size expression of type A to

integral

enumeration

type C is incompatible with C++98

warning: cast between pointer-to-function and pointer-to-object is incompatible with C++98

warning: empty macro arguments are incompatible with C++98

warning: commas at the end of enumerator lists are incompatible with C++98

warning: extern templates are incompatible with C++98

warning: ‘long long’ is incompatible with C++98

warning: C++98 requires newline at end of file

warning: #line number greater than 32767 is incompatible with C++98

warning: variadic macros are incompatible with C++98

-Wc++98-compat-unnamed-type-template-args ¶

Diagnostic text:

warning: unnamed type as template argument is incompatible with C++98

-Wc11-extensions ¶

Diagnostic text:

warning: anonymous unions are a C11 extension

warning: anonymous structs are a C11 extension

warning: ‘A’ is a C11 extension

warning: pointer comparisons before C11 need to be between two complete or two incomplete types; A is

complete and B is

complete

-Wc2x-compat ¶

Diagnostic text:

warning: ‘A’ is a keyword in C2x

-Wc2x-extensions ¶

Some of the diagnostics controlled by this flag are enabled by default.

Diagnostic text:

warning: ‘_BitInt’ suffix for literals is a C2x extension

warning: use of a ‘#

elifdef

elifndef

‘ directive is a C2x extension

warning: use of an empty initializer is a C2x extension

warning: label at end of compound statement is a C2x extension

warning: ‘nullptr’ is a C2x extension

warning: ‘_Static_assert’ with no message is a C2x extension

warning: omitting the parameter name in a function definition is a C2x extension

warning: [[]] attributes are a C2x extension

-Wc99-compat ¶

Some of the diagnostics controlled by this flag are enabled by default.

Diagnostic text:

warning:

using this character in an identifier

starting an identifier with this character

is incompatible with C99

warning: unicode literals are incompatible with C99

warning: ‘A’ is a keyword in C99

warning: integer literal is too large to be represented in type ‘long’, interpreting as ‘unsigned long’ per C89; this literal will

have type ‘long long’

be ill-formed

in C99 onwards

-Wc99-designator ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wc++20-designator.

Diagnostic text:

warning: designated initializers are a C99 feature

warning: array designators are a C99 extension

warning: brace elision for designated initializer is a C99 extension

warning: mixture of designated and non-designated initializers in the same initializer list is a C99 extension

warning: nested designators are a C99 extension

-Wc99-extensions ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wc99-designator.

Diagnostic text:

warning: initializer for aggregate is not a compile-time constant

warning:

qualifier in

static

array size

‘[*] ‘

is a C99 feature

warning: compound literals are a C99-specific feature

warning: ‘A’ is a C99 extension

warning: flexible array members are a C99 feature

warning: variable declaration in for loop is a C99-specific feature

warning: ISO C99 requires whitespace after the macro name

warning: empty macro arguments are a C99 feature

warning: commas at the end of enumerator lists are a C99-specific feature

warning: hexadecimal floating constants are a C99 feature

-Wcall-to-pure-virtual-from-ctor-dtor ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: call to pure virtual member function A has undefined behavior; overrides of A in subclasses are not available in the

constructor

destructor

of C

-Wcalled-once-parameter ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wcompletion-handler.

Diagnostic text:

warning: A parameter marked ‘called_once’ is called twice

warning:

captured

A parameter marked ‘called_once’ is never called

warning: A parameter marked ‘called_once’ is never

used

called

when

taking true branch

taking false branch

handling this case

none of the cases applies

entering the loop

skipping the loop

taking one of the branches

-Wcast-align ¶

Diagnostic text:

warning: cast from A to B increases required alignment from C to D

-Wcast-calling-convention ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: cast between incompatible calling conventions ‘A’ and ‘B’; calls through this pointer may abort at runtime

-Wcast-function-type ¶

Also controls -Wcast-function-type-strict.

Diagnostic text:

warning: cast

from A to B

converts to incompatible function type

-Wcast-function-type-strict ¶

Diagnostic text:

warning: cast

from A to B

converts to incompatible function type

-Wcast-of-sel-type ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: cast of type A to B is deprecated; use sel_getName instead

-Wcast-qual ¶

Diagnostic text:

warning: cast from A to B drops

const and volatile qualifiers

const qualifier

volatile qualifier

warning: cast from A to B must have all intermediate pointers const qualified to be safe

-Wcast-qual-unrelated ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ISO C++ does not allow

const_cast

static_cast

reinterpret_cast

dynamic_cast

C-style cast

functional-style cast

from B to C because it casts away qualifiers, even though the source and destination types are unrelated

-Wchar-align ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wchar-subscripts ¶

Diagnostic text:

warning: array section

lower bound

length

is of type ‘char’

warning: array subscript is of type ‘char’

-Wclang-cl-pch ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: support for ‘/Yc’ with more than one source file not implemented yet; flag ignored

warning: support for ‘/Yc’ and ‘/Yu’ with different filenames not implemented yet; flags ignored

warning: #pragma hdrstop filename not supported, /Fp can be used to specify precompiled header filename

warning: definition of macro A does not match definition in precompiled header

-Wclass-conversion ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: conversion function converting A to its base class B will never be used

warning: conversion function converting A to itself will never be used

warning: conversion function converting A to B will never be used

-Wclass-varargs ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wnon-pod-varargs.

Diagnostic text:

warning: passing object of class type A through variadic

function

block

method

constructor

; did you mean to call ‘D’?

-Wcmse-union-leak ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: passing union across security boundary via

parameter B

return value

may leak information

-Wcomma ¶

Diagnostic text:

warning: possible misuse of comma operator here

-Wcomment ¶

Some of the diagnostics controlled by this flag are enabled by default.

Diagnostic text:

warning: escaped newline between */ characters at block comment end

warning: // comments are not allowed in this language

warning: multi-line // comment

warning: ‘/*’ within block comment

-Wcompare-distinct-pointer-types ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: comparison of distinct pointer types

(A and B)

-Wcompletion-handler ¶

Diagnostic text:

warning: completion handler is called twice

warning:

captured

completion handler is never called

warning: completion handler is never

used

called

when

taking true branch

taking false branch

handling this case

none of the cases applies

entering the loop

skipping the loop

taking one of the branches

-Wcomplex-component-init ¶

Diagnostic text:

warning: complex initialization specifying real and imaginary components is an extension

-Wcompound-token-split ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wcompound-token-split-by-macro, -Wcompound-token-split-by-space.

-Wcompound-token-split-by-macro ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

B and

C tokens

introducing statement expression

terminating statement expression

introducing attribute

terminating attribute

forming pointer to member type

appear in different macro expansion contexts

-Wcompound-token-split-by-space ¶

Diagnostic text:

warning:

B and

C tokens

introducing statement expression

terminating statement expression

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘A’ will always evaluate to ‘true’ in a manifestly constant-evaluated expression

-Wconstant-logical-operand ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: use of logical ‘A’ with constant operand

-Wconstexpr-not-const ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘constexpr’ non-static member function will not be implicitly ‘const’ in C++14; add ‘const’ to avoid a change in behavior

-Wconsumed ¶

Diagnostic text:

warning: consumed analysis attribute is attached to member of class A which isn’t marked as consumable

warning: state of variable ‘A’ must match at the entry and exit of loop

warning: parameter ‘A’ not in expected state when the function returns: expected ‘B’, observed ‘C’

warning: argument not in expected state; expected ‘A’, observed ‘B’

warning: return state set for an unconsumable type ‘A’

warning: return value not in expected state; expected ‘A’, observed ‘B’

warning: invalid invocation of method ‘A’ on object ‘B’ while it is in the ‘C’ state

warning: invalid invocation of method ‘A’ on a temporary object while it is in the ‘B’ state

-Wconversion ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wbitfield-enum-conversion, -Wbool-conversion, -Wconstant-conversion, -Wenum-conversion, -Wfloat-conversion, -Wimplicit-float-conversion, -Wimplicit-int-conversion, -Wint-conversion, -Wliteral-conversion, -Wnon-literal-null-conversion, -Wnull-conversion, -Wobjc-literal-conversion, -Wshorten-64-to-32, -Wsign-conversion, -Wstring-conversion.

Diagnostic text:

warning: implicit conversion discards imaginary component: A to B

warning: implicit conversion turns vector to scalar: A to B

warning: passing non-generic address space pointer to A may cause dynamic conversion affecting performance

warning: non-type template argument with value ‘A’ converted to ‘B’ for unsigned template parameter of type C

warning: non-type template argument value ‘A’ truncated to ‘B’ for template parameter of type C

-Wcoro-non-aligned-allocation-function ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: under -fcoro-aligned-allocation, the non-aligned allocation function for the promise type A has higher precedence than the global aligned allocation function

-Wcoroutine ¶

This diagnostic is enabled by default.

Also controls -Walways-inline-coroutine, -Wcoro-non-aligned-allocation-function, -Wcoroutine-missing-unhandled-exception, -Wdeprecated-coroutine.

Diagnostic text:

warning: return type of ‘coroutine_handle<>::address should be ‘void*’ (have A) in order to get capability with existing async C API.

-Wcoroutine-missing-unhandled-exception ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: A is required to declare the member ‘unhandled_exception()’ when exceptions are enabled

-Wcovered-switch-default ¶

Diagnostic text:

warning: default label in switch which covers all enumeration values

-Wcstring-format-directive ¶

Diagnostic text:

warning: using A directive in

NSString

CFString

which is being passed as a formatting argument to the formatting

method

CFfunction

-Wctad-maybe-unsupported ¶

Also controls -Wdangling-field, -Wdangling-gsl, -Wdangling-initializer-list, -Wreturn-stack-address.

Diagnostic text:

warning:

temporary

whose address is used as value of

implicitly

bound to

reference

member of local variable

local

variable

reference

array backing

initializer list subobject of local variable

local initializer list

will be destroyed at the end of the full-expression

warning: sorry, lifetime extension of

temporary

backing array of initializer list

created by aggregate initialization using default member initializer is not supported; lifetime of

temporary

backing array

will end at the end of the full-expression

-Wdangling-else ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: add explicit braces to avoid dangling else

-Wdangling-field ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: binding reference member A to stack allocated

variable

parameter

warning:

reference

backing array for ‘std::initializer_list’

subobject of

member A

binds to

a temporary object whose lifetime is shorter than the lifetime of the constructed object

warning: initializing pointer member A with the stack address of

variable

parameter

warning: temporary bound to reference member of allocated object will be destroyed at the end of the full-expression

-Wdangling-gsl ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: object backing the pointer will be destroyed at the end of the full-expression

warning: initializing pointer member A to point to a temporary object whose lifetime is shorter than the lifetime of the constructed object

-Wdangling-initializer-list ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: array backing

initializer list subobject of the allocated object

the allocated initializer list

will be destroyed at the end of the full-expression

-Wdarwin-sdk-settings ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: SDK settings were ignored as ‘SDKSettings.json’ could not be parsed

This diagnostic is enabled by default.

Diagnostic text:

warning: explicitly defaulted

<ERROR>

equality

three-way

equality

relational

comparison operator is implicitly deleted

warning: explicitly defaulted

default constructor

copy constructor

move constructor

copy assignment operator

move assignment operator

destructor

is implicitly deleted

-Wdelegating-ctor-cycles ¶

This diagnostic is an error by default, but the flag -Wno-delegating-ctor-cycles can be used to disable the error.

Diagnostic text:

error: constructor for A creates a delegation cycle

-Wdelete-abstract-non-virtual-dtor ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

delete

destructor

called on B that is abstract but has non-virtual destructor

-Wdelete-incomplete ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: cannot delete expression with pointer-to-‘void’ type A

warning: deleting pointer to incomplete type A may cause undefined behavior

-Wdelete-non-abstract-non-virtual-dtor ¶

Diagnostic text:

warning:

delete

destructor

called on non-final B that has virtual functions but non-virtual destructor

-Wdelete-non-virtual-dtor ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wdelete-abstract-non-virtual-dtor, -Wdelete-non-abstract-non-virtual-dtor.

-Wdelimited-escape-sequence-extension ¶

Diagnostic text:

warning:

delimited

named

escape sequences are a

Clang

C++23

extension

-Wdeprecate-lax-vec-conv-all ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: Implicit conversion between vector types (’A’ and ‘B’) is deprecated. In the future, the behavior implied by ‘-fno-lax-vector-conversions’ will be the default.

-Wdeprecated ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wdeprecated-anon-enum-enum-conversion, -Wdeprecated-array-compare, -Wdeprecated-attributes, -Wdeprecated-builtins, -Wdeprecated-comma-subscript, -Wdeprecated-copy, -Wdeprecated-copy-with-dtor, -Wdeprecated-declarations, -Wdeprecated-dynamic-exception-spec, -Wdeprecated-enum-compare, -Wdeprecated-enum-compare-conditional, -Wdeprecated-enum-enum-conversion, -Wdeprecated-enum-float-conversion, -Wdeprecated-increment-bool, -Wdeprecated-literal-operator, -Wdeprecated-pragma, -Wdeprecated-redundant-constexpr-static-def, -Wdeprecated-register, -Wdeprecated-this-capture, -Wdeprecated-type, -Wdeprecated-volatile, -Wdeprecated-writable-strings.

Diagnostic text:

warning: -O4 is equivalent to -O3

warning: access declarations are deprecated; use using declarations instead

warning: argument ‘A’ is deprecated, use ‘B’ instead

warning: treating ‘A’ input as ‘B’ when in C++ mode, this behavior is deprecated

warning: ‘depend’ clause for ‘ordered’ is deprecated; use ‘doacross’ instead

warning: minus(-) operator for reductions is deprecated; use + or user defined reduction instead

warning: A does not support the option ‘B’

warning: Use of ‘long’ with ‘__vector’ is deprecated

-Wdeprecated-altivec-src-compat ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: Current handling of vector bool and vector pixel types in this context are deprecated. The default behaviour will soon change to that implied by the ‘-altivec-compat=xl’ option

-Wdeprecated-anon-enum-enum-conversion ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

arithmetic between

bitwise operation between

comparison of

conditional expression between

compound assignment of

different enumeration types

(B and C)

is deprecated

-Wdeprecated-array-compare ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: comparison between two arrays is deprecated; to compare array addresses, use unary ‘+’ to decay operands to pointers

-Wdeprecated-attributes ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: the ‘[[_Noreturn]]’ attribute spelling is deprecated in C2x; use ‘[[noreturn]]’ instead

warning: applying attribute A to a declaration is deprecated; apply it to the type instead

warning: specifying vector types with the ‘mode’ attribute is deprecated; use the ‘vector_size’ attribute instead

-Wdeprecated-builtins ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: builtin A is deprecated; use B instead

-Wdeprecated-comma-subscript ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: top-level comma expression in array subscript is deprecated in C++20 and unsupported in C++23

-Wdeprecated-copy ¶

Also controls -Wdeprecated-copy-with-user-provided-copy.

Diagnostic text:

warning: definition of implicit copy

constructor

assignment operator

for A is deprecated because it has a user-declared copy

assignment operator

constructor

-Wdeprecated-copy-dtor ¶

Synonym for -Wdeprecated-copy-with-dtor.

-Wdeprecated-copy-with-dtor ¶

Also controls -Wdeprecated-copy-with-user-provided-dtor.

Diagnostic text:

warning: definition of implicit copy

constructor

assignment operator

for A is deprecated because it has a user-declared destructor

-Wdeprecated-copy-with-user-provided-copy ¶

Diagnostic text:

warning: definition of implicit copy

constructor

assignment operator

for A is deprecated because it has a user-provided copy

assignment operator

constructor

-Wdeprecated-copy-with-user-provided-dtor ¶

Diagnostic text:

warning: definition of implicit copy

constructor

assignment operator

for A is deprecated because it has a user-provided destructor

-Wdeprecated-coroutine ¶

This diagnostic is enabled by default.

enumeration

type C

with

from

and

enumeration

floating-point

type D is deprecated

-Wdeprecated-implementations ¶

Diagnostic text:

warning: implementing deprecated

method

class

-Wdeprecated-increment-bool ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: incrementing expression of type bool is deprecated and incompatible with C++17

-Wdeprecated-literal-operator ¶

Diagnostic text:

warning: identifier A preceded by whitespace in a literal operator declaration is deprecated

-Wdeprecated-non-prototype ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: a function

declaration

definition

without a prototype is deprecated in all versions of C

and is not supported in C2x

and is treated as a zero-parameter prototype in C2x, conflicting with a

subsequent

declaration

definition

warning: passing arguments to

a function

without a prototype is deprecated in all versions of C and is not supported in C2x

-Wdeprecated-objc-isa-usage ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: assignment to Objective-C’s isa is deprecated in favor of object_setClass()

warning: direct access to Objective-C’s isa is deprecated in favor of object_getClass()

-Wdeprecated-objc-pointer-introspection ¶

This diagnostic is enabled by default.

Also controls -Wdeprecated-objc-pointer-introspection-performSelector.

Diagnostic text:

warning: bitmasking for introspection of Objective-C object pointers is strongly discouraged

-Wdeprecated-objc-pointer-introspection-performSelector ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: bitmasking for introspection of Objective-C object pointers is strongly discouraged

-Wdeprecated-pragma ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: macro A has been marked as deprecated

: C

-Wdeprecated-redundant-constexpr-static-def ¶

Diagnostic text:

warning: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated

-Wdeprecated-register ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘register’ storage class specifier is deprecated and incompatible with C++17

-Wdeprecated-static-analyzer-flag ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: analyzer option ‘A’ is deprecated. This flag will be removed in B, and passing this option will be an error.

warning: analyzer option ‘A’ is deprecated. This flag will be removed in B, and passing this option will be an error. Use ‘C’ instead.

-Wdeprecated-this-capture ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: implicit capture of ‘this’ with a capture default of ‘=’ is deprecated

-Wdeprecated-type ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘_ExtInt’ is deprecated; use ‘_BitInt’ instead

-Wdeprecated-volatile ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

decrement

increment

of object of volatile-qualified type B is deprecated

warning: use of result of assignment to object of volatile-qualified type A is deprecated

warning: volatile-qualified parameter type A is deprecated

warning: volatile-qualified return type A is deprecated

warning: volatile qualifier in structured binding declaration is deprecated

-Wdeprecated-writable-strings ¶

Synonym for -Wc++11-compat-deprecated-writable-strings.

-Wdirect-ivar-access ¶

Diagnostic text:

warning: instance variable A is being directly accessed

-Wdisabled-macro-expansion ¶

Diagnostic text:

warning: disabled expansion of recursive macro

-Wdisabled-optimization ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wdiscard-qual ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wdistributed-object-modifiers ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: conflicting distributed object modifiers on parameter type in implementation of A

warning: conflicting distributed object modifiers on return type in implementation of A

-Wdivision-by-zero ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

remainder

division

by zero is undefined

-Wdll-attribute-on-redeclaration ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: redeclaration of A should not add B attribute

-Wdllexport-explicit-instantiation-decl ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: explicit instantiation declaration should not be ‘dllexport’

-Wdllimport-static-field-def ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: definition of dllimport static field

-Wdocumentation ¶

Also controls -Wdocumentation-deprecated-sync, -Wdocumentation-html.

Diagnostic text:

warning: ‘

class

interface

protocol

struct

union

‘ command should not be used in a comment attached to a non-

class

interface

protocol

struct

union

declaration

warning: duplicated command ‘

B’

warning: empty paragraph passed to ‘

B’ command

warning: ‘

classdesign

coclass

dependency

helper

helperclass

helps

instancesize

ownership

performance

security

superclass

‘ command should not be used in a comment attached to a non-container declaration

warning: ‘

function

functiongroup

method

methodgroup

callback

‘ command should be used in a comment attached to

a function

an Objective-C method

a pointer to function

declaration

warning: HTML start tag prematurely ended, expected attribute name or ‘>’

warning: expected quoted string after equals sign

warning: ‘

B’ command has

word argument

, expected D

warning: parameter ‘A’ is already documented

warning: unrecognized parameter passing direction, valid directions are ‘[in]’, ‘[out]’ and ‘[in,out]’

warning: ‘

param’ command used in a comment that is not attached to a function declaration

warning: parameter ‘A’ not found in the function declaration

warning: ‘

B’ command used in a comment that is attached to a

function returning void

constructor

destructor

method returning void

warning: ‘

B’ command used in a comment that is not attached to a function or method declaration

warning: template parameter ‘A’ is already documented

warning: ‘

tparam’ command used in a comment that is not attached to a template declaration

warning: template parameter ‘A’ not found in the template declaration

warning: not a Doxygen trailing comment

warning: line splicing in Doxygen comments are not supported

warning: ‘

B’ command does not terminate a verbatim text block

-Wdocumentation-deprecated-sync ¶

Diagnostic text:

warning: declaration is marked with ‘

deprecated’ command but does not have a deprecation attribute

-Wdocumentation-html ¶

Diagnostic text:

warning: HTML end tag ‘A’ is forbidden

warning: HTML end tag does not match any start tag

warning: HTML tag ‘A’ requires an end tag

warning: HTML start tag ‘A’ closed by ‘B’

-Wdocumentation-pedantic ¶

Also controls -Wdocumentation-unknown-command.

Diagnostic text:

warning: whitespace is not allowed in parameter passing direction

-Wdocumentation-unknown-command ¶

Diagnostic text:

typedef

type alias

A of the class name

-Wduplicate-decl-specifier ¶

Some of the diagnostics controlled by this flag are enabled by default.

Diagnostic text:

warning: duplicate ‘A’ declaration specifier

warning: multiple identical address spaces specified for type

warning: duplicate ‘A’ declaration specifier

-Wduplicate-enum ¶

Diagnostic text:

warning: element A has been implicitly assigned B which another element has been assigned

-Wduplicate-method-arg ¶

Diagnostic text:

warning: redeclaration of method parameter A

This diagnostic is enabled by default.

Diagnostic text:

warning:

destination for

source of

first operand of

second operand of

this B call is a pointer to

class containing a

dynamic class D; vtable pointer will be

overwritten

copied

moved

compared

-Wdynamic-exception-spec ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wdeprecated-dynamic-exception-spec.

Diagnostic text:

error: ISO C++17 does not allow dynamic exception specifications

-Weager-load-cxx-named-modules ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: the form ‘-fmodule-file=<BMI-path>’ is deprecated for standard C++ named modules;consider to use ‘-fmodule-file=<module-name>=<BMI-path>’ instead

-Welaborated-enum-base ¶

This diagnostic is an error by default, but the flag -Wno-elaborated-enum-base can be used to disable the error.

Diagnostic text:

error: non-defining declaration of enumeration with a fixed underlying type is only permitted as a standalone declaration

; missing list of enumerators?

-Welaborated-enum-class ¶

This diagnostic is an error by default, but the flag -Wno-elaborated-enum-class can be used to disable the error.

Diagnostic text:

error: reference to enumeration must use ‘enum’ not ‘enum

struct

class

‘

-Wembedded-directive ¶

Diagnostic text:

warning: embedding a directive within macro arguments has undefined behavior

-Wempty-body ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: for loop has empty body

warning: if statement has empty body

warning: range-based for loop has empty body

warning: switch statement has empty body

warning: while loop has empty body

-Wempty-decomposition ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ISO C++17 does not allow a decomposition group to be empty

-Wempty-init-stmt ¶

Diagnostic text:

warning: empty initialization statement of ‘

switch

range-based for

‘ has no effect

-Wempty-translation-unit ¶

Diagnostic text:

warning: ISO C requires a translation unit to contain at least one declaration

-Wencode-type ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: encoding of A type is incomplete because B component has unknown encoding

-Wenum-compare ¶

This diagnostic is enabled by default.

Also controls -Wdeprecated-enum-compare, -Wenum-compare-switch.

Diagnostic text:

warning:

arithmetic between

bitwise operation between

comparison of

conditional expression between

compound assignment of

different enumeration types

(B and C)

-Wenum-compare-conditional ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wdeprecated-enum-compare-conditional.

Diagnostic text:

warning:

arithmetic between

bitwise operation between

comparison of

conditional expression between

compound assignment of

different enumeration types

(B and C)

-Wenum-compare-switch ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: comparison of different enumeration types in switch statement

(A and B)

-Wenum-constexpr-conversion ¶

This diagnostic is an error by default, but the flag -Wno-enum-constexpr-conversion can be used to disable the error.

Diagnostic text:

error: integer value A is outside the valid range of values [B, C] for the enumeration type D

-Wenum-conversion ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wenum-compare-conditional, -Wenum-enum-conversion, -Wenum-float-conversion.

Diagnostic text:

warning: implicit conversion from enumeration type A to different enumeration type B

-Wenum-enum-conversion ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wdeprecated-enum-enum-conversion.

Diagnostic text:

warning:

arithmetic between

bitwise operation between

comparison of

conditional expression between

compound assignment of

different enumeration types

(B and C)

-Wenum-float-conversion ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wdeprecated-enum-float-conversion.

Diagnostic text:

warning:

arithmetic between

bitwise operation between

comparison of

conditional expression between

compound assignment of

floating-point

enumeration

type C

with

from

and

enumeration

floating-point

type D

-Wenum-too-large ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: enumeration values exceed range of largest integer

warning: incremented enumerator value A is not representable in the largest integer type

-Wexceptions ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: cannot refer to a non-static member from the handler of a

constructor

destructor

function try block

warning: exception of type A will be caught by earlier handler

warning: A has a non-throwing exception specification but can still throw

-Wexcess-initializers ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: excess elements in

array

vector

scalar

union

struct

initializer

warning: excess elements in initializer for indivisible sizeless type A

warning: excess elements in char array initializer

warning: initializer-string for char array is too long

This diagnostic is enabled by default.

Diagnostic text:

warning: explicit call to +initialize results in duplicate call to +initialize

warning: explicit call to [super initialize] should only be in implementation of +initialize

-Wexplicit-ownership-type ¶

Diagnostic text:

warning: method parameter of type A with no explicit ownership

-Wexport-unnamed ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wextern-c-compat ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

empty

struct

union

Also controls -Wempty-init-stmt.

Diagnostic text:

warning: empty expression statement has no effect; remove unnecessary ‘;’ to silence this warning

-Wextra-tokens ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: extra tokens at end of #A directive

warning: extra tokens at the end of ‘#pragma omp A’ are ignored

-Wfinal-dtor-non-final-class ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: class with destructor marked ‘

final

sealed

‘ cannot be inherited from

-Wfinal-macro ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: macro A has been marked as final and should not be

undefined

redefined

This diagnostic is enabled by default.

Also controls -Wformat-extra-args, -Wformat-insufficient-args, -Wformat-invalid-specifier, -Wformat-security, -Wformat-y2k, -Wformat-zero-length, -Wnonnull.

Diagnostic text:

warning: using ‘%%P’ format specifier without precision

warning:

values of type

enum values with underlying type

‘A’ should not be used as format arguments; add an explicit cast to B instead

warning: using ‘A’ format specifier, but argument has boolean value

warning: format specifies type A but the argument has

type

underlying type

warning: using ‘A’ format specifier annotation outside of os_log()/os_trace()

warning: invalid position specified for

field width

field precision

warning: cannot mix positional and non-positional arguments in format string

warning: length modifier ‘A’ results in undefined behavior or no effect with ‘B’ conversion specifier

warning: format string should not be a wide string

warning: position arguments in format strings start counting at 1 (not 0)

warning: format string missing

warning: object format flags cannot be used with ‘A’ conversion specifier

warning: ‘

‘ specified field

width

precision

is missing a matching ‘int’ argument

warning: field

width

precision

should have type B, but argument has type C

warning: missing object format flag

warning: format string contains ‘\0’ within the string body

warning: format string is not null-terminated

warning: flag ‘A’ is ignored when flag ‘B’ is present

warning: incomplete format specifier

warning: ‘A’ is not a valid object format flag

warning: ‘%%n’ specifier not supported on this platform

warning: flag ‘A’ results in undefined behavior with ‘B’ conversion specifier

warning:

field width

precision

used with ‘B’ conversion specifier, resulting in undefined behavior

Diagnostic text:

warning: format string is not a string literal

-Wformat-pedantic ¶

Diagnostic text:

warning:

values of type

enum values with underlying type

‘A’ should not be used as format arguments; add an explicit cast to B instead

warning: format specifies type A but the argument has

type

underlying type

-Wformat-security ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: format string is not a string literal (potentially insecure)

-Wformat-type-confusion ¶

Diagnostic text:

warning: format specifies type A but the argument has

type

underlying type

-Wformat-y2k ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wformat-zero-length ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: format string is empty

-Wformat=2 ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wformat-nonliteral, -Wformat-security, -Wformat-y2k.

-Wfortify-source ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘A’ may overflow; destination buffer in argument B has size C, but the corresponding specifier may require size D

warning: ‘A’ will always overflow; destination buffer has size B, but format string expands to at least C

warning: ‘A’ will always overflow; destination buffer has size B, but size argument is C

warning: ‘A’ size argument is too large; destination buffer has size B, but size argument is C

warning: ‘A’ will always overflow; destination buffer has size B, but the source string has length C (including NUL byte)

-Wfour-char-constants ¶

Diagnostic text:

warning: multi-character character constant

-Wframe-address ¶

Diagnostic text:

warning: calling ‘A’ with a nonzero argument is unsafe

-Wframe-larger-than ¶

This diagnostic is enabled by default.

Diagnostic text:

The text of this diagnostic is not controlled by Clang.

warning: stack frame size (A) exceeds limit (B) in ‘C’

More fine grained information about the stack layout is available by adding the -Rpass-analysis=stack-frame-layout command-line flag to the compiler invocation.

The diagnostic information can be saved to a file in a machine readable format, like YAML by adding the -foptimization-record-file=<file> command-line flag.

Results can be filtered by function name by passing -mllvm -filter-print-funcs=foo, where foo is the target function’s name.

-Wframework-include-private-from-public ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: public framework header includes private framework header ‘A’

-Wfree-nonheap-object ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: attempt to call A on non-heap

object C

object: block expression

object: lambda-to-function-pointer conversion

-Wfunction-def-in-objc-container ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: function definition inside an Objective-C container is deprecated

-Wfunction-multiversion ¶

This diagnostic is enabled by default.

Also controls -Wtarget-clones-mixed-specifiers.

Diagnostic text:

warning: body of cpu_dispatch function will be ignored

warning: CPU list contains duplicate entries; attribute ignored

warning: version list contains duplicate entries

warning: version list contains entries that don’t impact code generation

-Wfuse-ld-path ¶

Diagnostic text:

warning: ‘-fuse-ld=’ taking a path is deprecated; use ‘–ld-path=’ instead

-Wfuture-attribute-extensions ¶

Controls -Wc++14-attribute-extensions, -Wc++17-attribute-extensions, -Wc++20-attribute-extensions.

-Wfuture-compat ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wgcc-compat ¶

Some of the diagnostics controlled by this flag are enabled by default.

Diagnostic text:

warning: ‘diagnose_if’ is a clang extension

warning: ‘enable_if’ is a clang extension

warning: __final is a GNU extension, consider using C++11 final

warning: GCC does not allow A attribute in this position on a function definition

warning: ‘break’ is bound to loop, GCC binds it to switch

warning: GCC does not allow the ‘cleanup’ attribute argument to be anything other than a simple identifier

warning: GCC does not allow an attribute in this position on a function declaration

warning: GCC does not allow the A attribute to be written on a type

warning: GCC requires a function with the A attribute to be variadic

warning: GCC does not allow variable declarations in for loop initializers before C99

warning: ‘A’ is bound to current loop, GCC binds it to the enclosing loop

-Wgeneric-type-extension ¶

Diagnostic text:

warning: passing a type argument as the first operand to ‘_Generic’ is a Clang extension

-Wglobal-constructors ¶

Diagnostic text:

warning: declaration requires a global constructor

warning: declaration requires a global destructor

-Wglobal-isel ¶

This diagnostic is enabled by default.

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wgnu-empty-struct ¶

Diagnostic text:

warning: empty

struct

union

is a GNU extension

warning: flexible array member A in otherwise empty

struct

interface

union

class

enum

is a GNU extension

warning:

struct

Diagnostic text:

warning: this style of line directive is a GNU extension

-Wgnu-null-pointer-arithmetic ¶

Diagnostic text:

warning: arithmetic on a null pointer treated as a cast from integer to pointer is a GNU extension

-Wgnu-offsetof-extensions ¶

Diagnostic text:

warning: defining a type within ‘

__builtin_offsetof

offsetof

‘ is a Clang extension

-Wgnu-pointer-arith ¶

Diagnostic text:

warning: arithmetic on

pointer

the

function type

and D

is a GNU extension

warning: subscript of a pointer to void is a GNU extension

warning: arithmetic on

pointer

to void is a GNU extension

-Wgnu-redeclared-enum ¶

Diagnostic text:

warning: redeclaration of already-defined enum A is a GNU extension

-Wgnu-statement-expression ¶

Also controls -Wgnu-statement-expression-from-macro-expansion.

Diagnostic text:

warning: use of GNU statement expression extension

Diagnostic text:

warning: cast to union type is a GNU extension

-Wgnu-variable-sized-type-not-at-end ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: field A with variable sized type B not at the end of a struct or class is a GNU extension

Diagnostic text:

warning: using namespace directive in global context in header

-Whip-omp-target-directives ¶

This diagnostic is an error by default, but the flag -Wno-hip-omp-target-directives can be used to disable the error.

Diagnostic text:

error: HIP does not support OpenMP target directives; directive has been ignored

-Whip-only ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘A’ is ignored since it is only supported for HIP

-Whlsl-extensions ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: access specifiers are a clang HLSL extension

-Widiomatic-parentheses ¶

Diagnostic text:

warning: using the result of an assignment as a condition without parentheses

-Wignored-attributes ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘trivial_abi’ cannot be applied to A

warning:

alias

ifunc

will always resolve to A even if weak definition of B is overridden

warning:

alias

ifunc

will not be in section ‘A’ but in the same section as the

aliasee

resolver

warning: requested alignment is less than minimum alignment of B for type A

warning: ‘abi_tag’ attribute on

non-inline

anonymous

namespace ignored

warning: attribute A after definition is ignored

warning: ‘cmse_nonsecure_entry’ cannot be applied to functions with internal linkage

warning: ‘dllexport’ attribute ignored on explicit instantiation definition

warning: attribute A has no effect when annotating an ‘if

constexpr

consteval

‘ statement

warning: attribute A has no effect when annotating an infinite loop

warning: A attribute can only be applied to instance variables or properties

warning: A attribute ignored

warning: A attribute ignored for field of type B

warning: A attribute is ignored because there exists no call expression inside the statement

warning: A attribute is ignored because B is not a function pointer

warning: A attribute ignored on inline function

warning: A attribute ignored on a non-definition declaration

warning: ‘A’ attribute cannot be specified on a definition

warning: attribute A ignored, because it is not attached to a declaration

warning: ‘nonnull’ attribute applied to function with no pointer arguments

warning: ‘nonnull’ attribute when used on parameters takes no arguments

warning: A attribute ignored when parsing type

warning: A attribute only applies to a pointer or reference (B is invalid)

warning: A attribute only applies to

constant

pointer arguments

warning: attribute declaration must precede definition

warning: A attribute only applies to return values that are pointers

warning: A attribute only applies to return values that are pointers or references

warning: ‘sentinel’ attribute requires named arguments

warning: ‘sentinel’ attribute only supported for variadic

functions

blocks

warning: A attribute argument not supported: B

warning: A attribute argument ‘B’ not supported on a global variable

warning: unknown visibility A

warning: attribute A cannot be applied to

functions

Objective-C method

without return value

warning: __weak attribute cannot be specified on a field declaration

warning: __weak attribute cannot be specified on an automatic variable when ARC is not enabled

warning: A

attribute

only applies to

functions

unions

variables and functions

functions and methods

functions, methods and blocks

functions, methods, and parameters

variables

variables and fields

variables, data members and tag types

types and namespaces

variables, functions and classes

kernel functions

non-K&R-style functions

warning: A

attribute

only applies to C

warning: conflicting attributes A are ignored

warning: attribute A ignored, because it cannot be applied to omitted return type

warning: A calling convention is not supported

for this target

on variadic function

on constructor/destructor

on builtin function

warning: attribute A ignored, because it cannot be applied to a type

warning: ignoring __declspec(allocator) because the function return type A is not a pointer or reference type

warning: attribute A is ignored, place it after “

class

struct

interface

union

enum

enum class

enum struct

“ to apply attribute to type declaration

warning: ‘deprecated’ attribute on anonymous namespace ignored

warning: A currently has no effect on a using declaration

warning: A redeclared inline; B attribute ignored

warning: attribute A is already applied with different arguments

warning: attribute A is already applied

warning: attribute is ignored on this statement as it only applies to functions; use ‘A’ on statements

warning: statement attribute A has higher precedence than function attribute ‘

always_inline

flatten

noinline

‘

warning: Objective-C GC does not allow weak variables on the stack

warning: ‘gnu_inline’ attribute requires function to be marked ‘inline’, attribute ignored

warning: inheritance model ignored on

primary template

partial specialization

warning: ‘objc_externally_retained’ can only be applied to local variables

of retainable type

with strong ownership

warning: import

module

name

cannot be applied to a function with a definition

warning: ‘internal_linkage’ attribute on a non-static local variable is ignored

warning:

MIPS

MSP430

RISC-V

‘interrupt’ attribute only applies to functions that have

no parameters

a ‘void’ return type

warning: qualifiers after comma in declarator list are ignored

warning: ‘mig_server_routine’ attribute only applies to routines that return a kern_return_t

warning: import

module

name

(B) does not match the import

module

name

warning: unknown attribute ‘A’

warning: ‘nocf_check’ attribute ignored; use -fcf-protection to enable the attribute

warning: ‘noderef’ can only be used on an array or pointer type

warning: ‘nothrow’ attribute conflicts with exception specification; attribute ignored

warning: A attribute only applies to

Objective-C object

pointer

pointer-to-CF-pointer

pointer/reference-to-OSObject-pointer

parameters

warning: A attribute only applies to

functions

methods

properties

that return

an Objective-C object

a pointer

a non-retainable pointer

warning: A attribute isn’t implemented by this Objective-C runtime

warning: direct attribute on property A ignored (not implemented by this Objective-C runtime)

warning: A attribute is deprecated and ignored in B

warning: ‘require_constant_initialization’ attribute added after initialization of variable

warning: repeated RISC-V ‘interrupt’ attribute

warning: template parameter of a function template with the ‘sycl_kernel’ attribute cannot be a non-type template parameter

warning: function template with ‘sycl_kernel’ attribute must have a single parameter

warning: ‘sycl_kernel’ attribute only applies to a function template with at least two template parameters

warning: function template with ‘sycl_kernel’ attribute must have a ‘void’ return type

warning:

alignment

size

of field B (C bits) does not match the

alignment

size

of the first field in transparent union; transparent_union attribute ignored

warning: first field of a transparent union cannot have

floating point

vector

type B; transparent_union attribute ignored

warning: transparent_union attribute can only be applied to a union definition; attribute ignored

warning: transparent union definition must contain at least one field; transparent_union attribute ignored

warning: ‘A’ only applies to

function

pointer

Objective-C object or block pointer

types; type here is C

warning: __declspec attribute A is not supported

warning:

unsupported

duplicate

unknown

CPU

tune CPU

‘C’ in the ‘

target

target_clones

target_version

‘ attribute string; ‘

target

target_clones

target_version

‘ attribute ignored

warning: ‘[[

nodiscard

gnu::warn_unused_result

]]’ attribute ignored when applied to a typedef; consider using ‘__attribute__((warn_unused_result))’ or ‘[[clang::warn_unused_result]]’ instead

warning: ‘__clang__’ is a predefined macro name, not an attribute scope specifier; did you mean ‘_Clang’ instead?

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wignored-pragmas ¶

This diagnostic is enabled by default.

Also controls -Wignored-pragma-intrinsic, -Wignored-pragma-optimize.

Diagnostic text:

warning: expected string literal in ‘clause A’ - ignoring

warning: expected ‘=’ following ‘#pragma

align

options align

‘ - ignored

warning: invalid alignment option in ‘#pragma

align

options align

‘ - ignored

warning: ‘#pragma comment A’ ignored

warning:

value

type

-dependent expression passed as an argument to debug command

warning: missing argument to debug command ‘A’

warning: missing debug command

warning: unexpected argument to debug command

warning: unexpected debug command ‘A’

warning: unknown module ‘A’

warning: expected action or ‘)’ in ‘#pragma A’ - ignored

warning: missing ‘:’ after A - ignoring

warning: missing ‘:’ or ‘)’ after A - ignoring

warning: expected ‘,’ in ‘#pragma A’

warning: expected identifier in ‘#pragma A’ - ignored

warning: expected ‘compiler’, ‘lib’, ‘user’, or a string literal for the section name in ‘#pragma A’ - ignored

warning: expected integer between A and B inclusive in ‘#pragma C’ - ignored

warning: missing ‘(’ after ‘#pragma A’ - ignoring

warning: expected non-wide string literal in ‘#pragma A’

warning: expected

‘enable’, ‘disable’, ‘begin’ or ‘end’

‘disable’

- ignoring

warning: expected ‘)’ or ‘,’ in ‘#pragma A’

warning: missing ‘)’ after ‘#pragma A’ - ignoring

warning: expected a stack label or a string literal for the section name in ‘#pragma A’ - ignored

warning: expected a string literal for the section name in ‘#pragma A’ - ignored

warning: expected push, pop or a string literal for the section name in ‘#pragma A’ - ignored

warning: expected string literal in ‘#pragma A’ - ignoring

warning: extra tokens at end of ‘#pragma A’ - ignored

warning: incorrect use of #pragma clang force_cuda_host_device begin|end

warning: ‘#pragma A’ is not supported on this target - ignored

warning: ‘#pragma init_seg’ is only supported when targeting a Microsoft environment

warning: unknown action for ‘#pragma A’ - ignored

warning: unexpected argument ‘A’ to ‘#pragma B’

; expected D

warning: unknown action ‘B’ for ‘#pragma A’ - ignored

warning: missing argument to ‘#pragma A’

; expected C

warning: incorrect use of ‘#pragma fenv_access (on|off)’ - ignored

warning: incorrect use of ‘#pragma ms_struct on|off’ - ignored

warning: #pragma options align=reset failed: A

warning: expected ‘align’ following ‘#pragma options’ - ignored

warning: expected #pragma pack parameter to be ‘1’, ‘2’, ‘4’, ‘8’, or ‘16’

warning: expected integer or identifier in ‘#pragma pack’ - ignored

warning: #pragma A(pop, …) failed: B

warning: pragma pop_macro could not pop ‘A’, no matching push_macro

warning: OpenCL extension A unknown or does not require pragma - ignoring

warning: known but unsupported action ‘B’ for ‘#pragma A’ - ignored

warning: unsupported OpenCL extension A - ignoring

warning: expected ‘#pragma unused’ argument to be a variable name

warning: only variables can be arguments to ‘#pragma unused’

warning: undeclared variable A used as an argument for ‘#pragma unused’

warning: invalid or unsupported rounding mode in ‘#pragma STDC FENV_ROUND’ - ignored

-Wignored-qualifiers ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wignored-reference-qualifiers.

Diagnostic text:

warning: ARC

unused

__unsafe_unretained

__strong

__weak

__autoreleasing

lifetime qualifier on return type is ignored

warning: ‘A’ qualifier on omitted return type B has no effect

warning: ‘A’ type qualifier

on return type

has

have

no effect

warning: ‘A’ qualifier on function type B has no effect

-Wignored-reference-qualifiers ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘A’ qualifier on reference type B has no effect

-Wimplicit ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wimplicit-function-declaration, -Wimplicit-int.

-Wimplicit-atomic-properties ¶

Diagnostic text:

warning: property is assumed atomic when auto-synthesizing the property

warning: property is assumed atomic by default

-Wimplicit-const-int-float-conversion ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: implicit conversion from C to D changes value from A to B

-Wimplicit-conversion-floating-point-to-bool ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: implicit conversion turns floating-point number into bool: A to B

-Wimplicit-exception-spec-mismatch ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: function previously declared with an

explicit

implicit

exception specification redeclared with an

implicit

explicit

exception specification

-Wimplicit-fallthrough ¶

Also controls -Wimplicit-fallthrough-per-function.

Diagnostic text:

warning: unannotated fall-through between switch labels

-Wimplicit-fallthrough-per-function ¶

Diagnostic text:

warning: unannotated fall-through between switch labels in partly-annotated function

-Wimplicit-fixed-point-conversion ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: implicit conversion from A cannot fit within the range of values for B

-Wimplicit-float-conversion ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wimplicit-int-float-conversion, -Wobjc-signed-char-bool-implicit-float-conversion.

Diagnostic text:

warning: implicit conversion loses floating-point precision: A to B

warning: implicit conversion when assigning computation result loses floating-point precision: A to B

-Wimplicit-function-declaration ¶

Some of the diagnostics controlled by this flag are enabled by default.

Diagnostic text:

error: call to undeclared function A; ISO C99 and later do not support implicit function declarations

warning: implicitly declaring library function ‘A’ with type B

error: call to undeclared library function ‘A’ with type B; ISO C99 and later do not support implicit function declarations

error: use of unknown builtin A

warning: implicit declaration of function A

-Wimplicit-int ¶

Some of the diagnostics controlled by this flag are enabled by default.

Diagnostic text:

error: type specifier missing, defaults to ‘int’; ISO C99 and later do not support implicit int

error: parameter A was not declared, defaults to ‘int’; ISO C99 and later do not support implicit int

warning: type specifier missing, defaults to ‘int’

-Wimplicit-int-conversion ¶

Also controls -Wobjc-signed-char-bool-implicit-int-conversion.

Diagnostic text:

warning: higher order bits are zeroes after implicit conversion

warning: implicit conversion loses integer precision: A to B

-Wimplicit-int-float-conversion ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wimplicit-const-int-float-conversion.

Diagnostic text:

warning: implicit conversion from A to B may lose precision

-Wimplicit-retain-self ¶

Diagnostic text:

warning: block implicitly retains ‘self’; explicitly mention ‘self’ to indicate this is intended behavior

-Wimplicitly-unsigned-literal ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: integer literal is too large to be represented in a signed integer type, interpreting as unsigned

-Wimport ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

This diagnostic is enabled by default.

Diagnostic text:

warning: exception specifications of

return

argument

types differ

warning: target exception specification is not superset of source

-Wincompatible-function-pointer-types ¶

This diagnostic is an error by default, but the flag -Wno-incompatible-function-pointer-types can be used to disable the error.

Diagnostic text:

error: incompatible function pointer types

assigning to A from B

assigning to different types

passing A to parameter of type B

passing to parameter of different type

returning A from a function with result type B

returning from function with different return type

converting A to type B

converting between types

initializing A with an expression of type B

initializing with expression of different type

sending A to parameter of type B

sending to parameter of different type

casting A to type B

casting between types

; dereference with *

; take the address with &

; remove *

; remove &

-Wincompatible-function-pointer-types-strict ¶

Diagnostic text:

warning: incompatible function pointer types

assigning to A from B

assigning to different types

passing A to parameter of type B

passing to parameter of different type

returning A from a function with result type B

returning from function with different return type

converting A to type B

converting between types

initializing A with an expression of type B

initializing with expression of different type

sending A to parameter of type B

sending to parameter of different type

casting A to type B

casting between types

; dereference with *

; take the address with &

; remove *

; remove &

-Wincompatible-library-redeclaration ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: incompatible redeclaration of library function A

-Wincompatible-ms-struct ¶

This diagnostic is an error by default, but the flag -Wno-incompatible-ms-struct can be used to disable the error.

Diagnostic text:

error: ms_struct may not produce Microsoft-compatible layouts for classes with base classes or virtual functions

error: ms_struct may not produce Microsoft-compatible layouts with fundamental data types with sizes that aren’t a power of two

-Wincompatible-pointer-types ¶

This diagnostic is enabled by default.

Also controls -Wincompatible-function-pointer-types, -Wincompatible-pointer-types-discards-qualifiers.

Diagnostic text:

warning: incompatible pointer types

assigning to A from B

assigning to different types

passing A to parameter of type B

passing to parameter of different type

returning A from a function with result type B

returning from function with different return type

converting A to type B

converting between types

initializing A with an expression of type B

initializing with expression of different type

sending A to parameter of type B

sending to parameter of different type

casting A to type B

casting between types

; dereference with *

; take the address with &

; remove *

; remove &

-Wincompatible-pointer-types-discards-qualifiers ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

assigning to A from B

assigning to different types

passing A to parameter of type B

passing to parameter of different type

returning A from a function with result type B

returning from function with different return type

converting A to type B

converting between types

initializing A with an expression of type B

initializing with expression of different type

sending A to parameter of type B

sending to parameter of different type

casting A to type B

casting between types

discards qualifiers in nested pointer types

warning:

assigning to A from B

assigning to different types

passing A to parameter of type B

passing to parameter of different type

returning A from a function with result type B

returning from function with different return type

converting A to type B

converting between types

initializing A with an expression of type B

initializing with expression of different type

sending A to parameter of type B

sending to parameter of different type

casting A to type B

casting between types

discards qualifiers

warning:

reinterpret_cast

C-style cast

from B to C changes address space of nested pointers

-Wincompatible-property-type ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: property type A is incompatible with type B inherited from C

-Wincompatible-sysroot ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: using sysroot for ‘A’ but targeting ‘B’

-Wincomplete-framework-module-declaration ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: skipping ‘A’ because module declaration of ‘B’ lacks the ‘framework’ qualifier

-Wincomplete-implementation ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: method definition for A not found

-Wincomplete-module ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wincomplete-umbrella, -Wnon-modular-include-in-module.

-Wincomplete-setjmp-declaration ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: declaration of built-in function ‘A’ requires the declaration of the ‘jmp_buf’ type, commonly provided in the header <setjmp.h>.

-Wincomplete-umbrella ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: missing submodule ‘A’

warning: umbrella directory ‘A’ not found

warning: umbrella header for module ‘A’ does not include header ‘B’

-Winconsistent-dllimport ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: A redeclared without B attribute: previous B ignored

warning: A redeclared without ‘dllimport’ attribute: ‘dllexport’ attribute added

-Winconsistent-missing-destructor-override ¶

Diagnostic text:

warning: A overrides a destructor but is not marked ‘override’

-Winconsistent-missing-override ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: A overrides a member function but is not marked ‘override’

-Wincrement-bool ¶

This diagnostic is enabled by default.

Also controls -Wdeprecated-increment-bool.

Diagnostic text:

error: ISO C++17 does not allow incrementing expression of type bool

-Winfinite-recursion ¶

passing to parameter of different type

returning A from a function with result type B

returning from function with different return type

converting A to type B

converting between types

initializing A with an expression of type B

initializing with expression of different type

sending A to parameter of type B

sending to parameter of different type

casting A to type B

casting between types

; dereference with *

; take the address with &

; remove *

; remove &

error: incompatible pointer to integer conversion

assigning to A from B

assigning to different types

passing A to parameter of type B

passing to parameter of different type

returning A from a function with result type B

returning from function with different return type

converting A to type B

converting between types

initializing A with an expression of type B

initializing with expression of different type

sending A to parameter of type B

sending to parameter of different type

casting A to type B

casting between types

; dereference with *

; take the address with &

; remove *

; remove &

-Wint-in-bool-context ¶

Diagnostic text:

warning: converting the enum constant to a boolean

warning: converting the result of ‘<<’ to a boolean; did you mean ‘(A) != 0’?

-Wint-to-pointer-cast ¶

This diagnostic is enabled by default.

Also controls -Wint-to-void-pointer-cast.

Diagnostic text:

warning: cast to B from smaller integer type A

-Wint-to-void-pointer-cast ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: cast to B from smaller integer type A

-Winteger-overflow ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: overflow in expression; result is A with type B

-Winterrupt-service-routine ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: interrupt service routine should only call a function with attribute ‘no_caller_saved_registers’

-Winvalid-command-line-argument ¶

This diagnostic is enabled by default.

Also controls -Wignored-optimization-argument.

Diagnostic text:

warning: missing plugin argument for plugin A in B

warning: missing plugin name in A

warning: the given MCU supports A hardware multiply, but ‘-mhwmult’ is set to B

warning: no MCU device specified, but ‘-mhwmult’ is set to ‘auto’, assuming no hardware multiply; use ‘-mmcu’ to specify an MSP430 device, or ‘-mhwmult’ to set the hardware multiply type explicitly

warning: the given MCU does not support hardware multiply, but ‘-mhwmult’ is set to A

warning: the object size sanitizer has no effect at -O0, but is explicitly enabled: A

warning: optimization level ‘A’ is not supported; using ‘BC’ instead

warning: feature flag ‘A’ must start with either ‘+’ to enable the feature or ‘-’ to disable it; flag ignored

warning: feature flag ‘A’ is ignored since the feature is read only

warning: mismatch between architecture and environment in target triple ‘A’; did you mean ‘B’?

warning: ignoring extension ‘A’ because the ‘B’ architecture does not support it

-Winvalid-constexpr ¶

This diagnostic is an error by default, but the flag -Wno-invalid-constexpr can be used to disable the error.

Diagnostic text:

error:

constexpr

consteval

function

constructor

never produces a constant expression

-Winvalid-iboutlet ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

instance variable

property

with A attribute must be an object type (invalid B)

warning: IBOutletCollection properties should be copy/strong and not assign

-Winvalid-initializer-from-system-header ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: invalid constructor from class in system header, should not be explicit

-Winvalid-ios-deployment-target ¶

This diagnostic is an error by default, but the flag -Wno-invalid-ios-deployment-target can be used to disable the error.

Diagnostic text:

error: invalid iOS deployment version ‘A’, iOS 10 is the maximum deployment target for 32-bit targets

Diagnostic text:

warning: unable to find A directory, expected to be in ‘B’ found via C

-Winvalid-partial-specialization ¶

This diagnostic is an error by default, but the flag -Wno-invalid-partial-specialization can be used to disable the error.

Diagnostic text:

error:

class

variable

template partial specialization is not more specialized than the primary template

-Winvalid-pch ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Winvalid-pp-token ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: empty character constant

warning: missing terminating

‘

‘”’

character

-Winvalid-source-encoding ¶

This diagnostic is enabled by default.

This diagnostic is enabled by default.

Diagnostic text:

warning: keyword ‘A’ will be made available as an identifier

here

for the remainder of the translation unit

-Wkeyword-macro ¶

Diagnostic text:

warning: keyword is hidden by macro definition

-Wknr-promoted-parameter ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

promoted type A of K&R function parameter is not compatible with the parameter type B

promoted type of K&R function parameter is not compatible with parameter type

-Wliteral-conversion ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: implicit conversion from A to B changes value from C to D

warning: implicit conversion of out of range value from A to B is undefined

-Wliteral-range ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: floating-point comparison is always

true

false

; constant cannot be represented exactly in type B

warning: magnitude of floating-point constant too large for type A; maximum is B

warning: magnitude of floating-point constant too small for type A; minimum is B

-Wlocal-type-template-args ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wc++98-compat-local-type-template-args.

Diagnostic text:

warning: template argument uses local type A

-Wlogical-not-parentheses ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: logical not is only applied to the left hand side of this

comparison

bitwise operator

-Wlogical-op-parentheses ¶

Diagnostic text:

warning: ‘&&’ within ‘||’

-Wlong-long ¶

Also controls -Wc++11-long-long.

Diagnostic text:

warning: ‘long long’ is an extension when C99 mode is not enabled

-Wloop-analysis ¶

-Wmax-unsigned-zero ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: taking the max of

structs

unions

are a Microsoft extension

-Wmicrosoft-cast ¶

This diagnostic is enabled by default.

Diagnostic text:

This diagnostic is enabled by default.

Diagnostic text:

warning: explicit constructor calls are a Microsoft extension

-Wmicrosoft-extra-qualification ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: extra qualification on member A

-Wmicrosoft-fixed-enum ¶

Diagnostic text:

warning: enumeration types with a fixed underlying type are a Microsoft extension

-Wmicrosoft-flexible-array ¶

Diagnostic text:

warning: flexible array member A in otherwise empty

struct

interface

union

class

This diagnostic is enabled by default.

Diagnostic text:

warning: function definition with pure-specifier is a Microsoft extension

This diagnostic is enabled by default.

Also controls -Wmicrosoft-template-shadow.

Diagnostic text:

warning: duplicate explicit instantiation of A ignored as a Microsoft extension

warning: use of member A found via unqualified lookup into dependent bases of class templates is a Microsoft extension

warning: use of member A before its declaration is a Microsoft extension

warning: using the undeclared type A as a default template argument is a Microsoft extension

warning: non-type template argument containing a dereference operation is a Microsoft extension

warning:

class template

class template partial

variable template

variable template partial

function template

member function

static data member

member class

member enumeration

specialization of B not in

a namespace enclosing C

class C or an enclosing namespace

is a Microsoft extension

warning: template argument for template type parameter must be a type; omitted ‘typename’ is a Microsoft extension

while

‘

-Wmismatched-new-delete ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘delete

[]

‘ applied to a pointer that was allocated with ‘new

[]

‘; did you mean ‘delete

[]

‘?

-Wmismatched-parameter-types ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: conflicting parameter types in implementation of A

: B vs C

-Wmismatched-return-types ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: conflicting return type in implementation of A

: B vs C

-Wmismatched-tags ¶

Diagnostic text:

warning: C defined as

a struct

an interface

a class

template

here but previously declared as

a struct

an interface

a class

template

; this is valid, but may result in linker errors under the Microsoft C++ ABI

warning:

struct

interface

class

template

C was previously declared as a

struct

interface

-Wmissing-field-initializers ¶

Diagnostic text:

warning: missing field A initializer

-Wmissing-format-attribute ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wmissing-include-dirs ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

Diagnostic text:

warning: block could be declared with attribute ‘noreturn’

warning:

function

method

B could be declared with attribute ‘noreturn’

-Wmissing-prototype-for-cc ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: function with no prototype cannot use the A calling convention

Diagnostic text:

warning: no previous extern declaration for non-static variable A

-Wmisspelled-assumption ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: unknown assumption string ‘A’ may be misspelled; attribute is potentially ignored, did you mean ‘B’?

-Rmodule-build ¶

Diagnostic text:

remark: building module ‘A’ as ‘B’

remark: finished building module ‘A’

remark: could not acquire lock file for module ‘A’: B

remark: timed out waiting to acquire lock file for module ‘A’

-Wmodule-conflict ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: module ‘A’ conflicts with already-imported module ‘B’: C

warning: module file ‘A’ was validated as a system module and is now being imported as a non-system module; any difference in diagnostic options will be ignored

-Wmodule-file-config-mismatch ¶

This diagnostic is an error by default, but the flag -Wno-module-file-config-mismatch can be used to disable the error.

Diagnostic text:

error: module file A cannot be loaded due to a configuration mismatch with the current compilation

-Wmodule-file-extension ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: duplicate module file extension block name ‘A’

-Rmodule-import ¶

Diagnostic text:

remark: importing module ‘A’

into ‘D’

from ‘B’

-Wmodule-import-in-extern-c ¶

This diagnostic is an error by default, but the flag -Wno-module-import-in-extern-c can be used to disable the error.

Diagnostic text:

error: import of C++ module ‘A’ appears within extern “C” language linkage specification

-Rmodule-include-translation ¶

Diagnostic text:

remark: treating #

include

import

include_next

__include_macros

as an import of module ‘B’

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Warray-parameter, -Wbool-operation, -Wcast-of-sel-type, -Wchar-subscripts, -Wcomment, -Wdelete-non-virtual-dtor, -Wextern-c-compat, -Wfor-loop-analysis, -Wformat, -Wframe-address, -Wimplicit, -Winfinite-recursion, -Wint-in-bool-context, -Wmismatched-tags, -Wmissing-braces, -Wmove, -Wmultichar, -Wobjc-designated-initializers, -Wobjc-flexible-array, -Wobjc-missing-super-calls, -Woverloaded-virtual, -Wprivate-extern, -Wrange-loop-construct, -Wreorder, -Wreturn-type, -Wself-assign, -Wself-move, -Wsizeof-array-argument, -Wsizeof-array-decay, -Wstring-plus-int, -Wtautological-compare, -Wtrigraphs, -Wuninitialized, -Wunknown-pragmas, -Wunused, -Wuser-defined-warnings, -Wvolatile-register-var.

-Wmove ¶

Controls -Wpessimizing-move, -Wredundant-move, -Wreturn-std-move, -Wself-move.

-Wmsvc-not-found ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: unable to find a Visual Studio installation; try running Clang from a developer command prompt

-Wmulti-gpu ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: multiple A architectures are detected: B; only the first one is used for ‘C’

-Wmultichar ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: multi-character character constant

-Wmultiple-move-vbase ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: defaulted move assignment operator of A will move assign virtual base class B multiple times

-Wnested-anon-types ¶

Diagnostic text:

warning: anonymous types declared in an anonymous

struct

warning: dereferencing A; was declared with a ‘noderef’ type

warning: dereferencing expression marked as ‘noderef’

warning: casting to dereferenceable pointer removes ‘noderef’ attribute

-Wnon-c-typedef-for-linkage ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: anonymous non-C-compatible type given name for linkage purposes by

non-POD

non-trivial

type B through variadic

function

block

method

constructor

; call will abort at runtime

error: cannot pass

non-POD

non-trivial

object of type B to variadic

function

block

method

constructor

; expected type from format string was D

error: second argument to ‘va_arg’ is of non-POD type A

error: second argument to ‘va_arg’ is of ARC ownership-qualified type A

-Wnon-power-of-two-alignment ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: requested alignment is not a power of 2

-Wnon-virtual-dtor ¶

Diagnostic text:

warning: A has virtual functions but non-virtual destructor

-Wnonnull ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: null passed to a callee that requires a non-null argument

warning: null returned from

function

method

that requires a non-null return value

-Wnonportable-cfstrings ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wnonportable-include-path ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: non-portable path to file ‘A’; specified path differs in case from file name on disk

-Wnonportable-system-include-path ¶

Diagnostic text:

warning: non-portable path to file ‘A’; specified path differs in case from file name on disk

-Wnonportable-vector-initialization ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: vector initializers are not compatible with NEON intrinsics in big endian mode

-Wnontrivial-memaccess ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

destination for

source of

first operand of

second operand of

this B call is a pointer to record C that is not trivial to

This diagnostic is enabled by default.

Diagnostic text:

warning: null character(s) preserved in

char

string

literal

warning: null character ignored

-Wnull-conversion ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: implicit conversion of

NULL

nullptr

constant to B

-Wnull-dereference ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: binding dereferenced null pointer to reference has undefined behavior

warning: indirection of non-volatile null pointer will be deleted, not trap

-Wnull-pointer-arithmetic ¶

Also controls -Wgnu-null-pointer-arithmetic.

Diagnostic text:

warning: performing pointer arithmetic on a null pointer has undefined behavior

if the offset is nonzero

-Wnull-pointer-subtraction ¶

Diagnostic text:

warning: performing pointer subtraction with a null pointer

has

may have

undefined behavior

-Wnullability ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: conflicting nullability specifier on parameter types, A conflicts with existing specifier B

warning: conflicting nullability specifier on return types, A conflicts with existing specifier B

warning: nullability specifier A conflicts with existing specifier B

warning: synthesized setter A for null_resettable property B does not handle nil

warning: duplicate nullability specifier A

-Wnullability-completeness ¶

This diagnostic is enabled by default.

Also controls -Wnullability-completeness-on-arrays.

Diagnostic text:

warning:

pointer

block pointer

member pointer

is missing a nullability type specifier (_Nonnull, _Nullable, or _Null_unspecified)

-Wnullability-completeness-on-arrays ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: array parameter is missing a nullability type specifier (_Nonnull, _Nullable, or _Null_unspecified)

-Wnullability-declspec ¶

This diagnostic is an error by default, but the flag -Wno-nullability-declspec can be used to disable the error.

Diagnostic text:

error: nullability specifier A cannot be applied to non-pointer type B; did you mean to apply the specifier to the

pointer

block pointer

member pointer

function pointer

member function pointer

-Wnullability-extension ¶

Diagnostic text:

warning: type nullability specifier A is a Clang extension

-Wnullability-inferred-on-nested-type ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: inferring ‘_Nonnull’ for pointer type within

array

reference

is deprecated

-Wnullable-to-nonnull-conversion ¶

Diagnostic text:

warning: implicit conversion from nullable pointer A to non-nullable pointer type B

-Wobjc-autosynthesis-property-ivar-name-match ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: autosynthesized property A will use

synthesized

instance variable C, not existing instance variable D

-Wobjc-bool-constant-conversion ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: implicit conversion from constant value A to ‘BOOL’; the only well defined values for ‘BOOL’ are YES and NO

-Wobjc-boxing ¶

dictionary key type

dictionary value type

-Wobjc-macro-redefinition ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ignoring redefinition of Objective-C qualifier macro

-Wobjc-messaging-id ¶

Diagnostic text:

warning: messaging unqualified id

-Wobjc-method-access ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: class method A not found (return type defaults to ‘id’)

warning: class method A not found (return type defaults to ‘id’); did you mean C?

warning: instance method A not found (return type defaults to ‘id’)

warning: instance method A not found (return type defaults to ‘id’); did you mean C?

warning: instance method A found instead of class method B

warning: instance method A is being used on ‘Class’ which is not in the root class

Diagnostic text:

warning: ‘assign’ property of object type may become a dangling reference; consider using ‘unsafe_unretained’

-Wobjc-property-implementation ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: class property A requires method B to be defined - use @dynamic or provide a method implementation in this class implementation

warning: class property A requires method B to be defined - use @dynamic or provide a method implementation in this category

warning: property A requires method B to be defined - use @synthesize, @dynamic or provide a method implementation in this class implementation

warning: property A requires method B to be defined - use @dynamic or provide a method implementation in this category

-Wobjc-property-implicit-mismatch ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: primary property declaration is implicitly strong while redeclaration in class extension is weak

-Wobjc-property-matches-cocoa-ownership-rule ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: property follows Cocoa naming convention for returning ‘owned’ objects

-Wobjc-property-no-attribute ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: default property attribute ‘assign’ not appropriate for object

warning: no ‘assign’, ‘retain’, or ‘copy’ attribute is specified - ‘assign’ is assumed

-Wobjc-property-synthesis ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: auto property synthesis will not synthesize property A; it will be implemented by its superclass, use @dynamic to acknowledge intention

warning: auto property synthesis will not synthesize property A because it is ‘readwrite’ but it will be synthesized ‘readonly’ via another property

warning: auto property synthesis will not synthesize property A because it cannot share an ivar with another synthesized property

-Wobjc-protocol-method-implementation ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: category is implementing a method which will also be implemented by its primary class

-Wobjc-protocol-property-synthesis ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: auto property synthesis will not synthesize property A declared in protocol B

-Wobjc-protocol-qualifiers ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: parameterized class A already conforms to the protocols listed; did you forget a ‘*’?

-Wobjc-readonly-with-setter-property ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: setter cannot be specified for a readonly property

-Wobjc-redundant-api-use ¶

Synonym for -Wobjc-redundant-literal-use.

-Wobjc-redundant-literal-use ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: using A with a literal is redundant

-Wobjc-root-class ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: class A defined without specifying a base class

-Wobjc-signed-char-bool ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wobjc-bool-constant-conversion, -Wobjc-signed-char-bool-implicit-float-conversion, -Wobjc-signed-char-bool-implicit-int-conversion, -Wtautological-objc-bool-compare.

-Wobjc-signed-char-bool-implicit-float-conversion ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: implicit conversion from floating-point type A to ‘BOOL’

This diagnostic is enabled by default.

Diagnostic text:

warning: A is incompatible with selectors that return a

struct

union

vector

type

-Wodr ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: template parameter lists have a different number of parameters (A vs B)

warning: template parameter has different kinds in different translation units

warning: field A declared with incompatible types in different translation units (B vs. C)

warning: external function A declared with incompatible types in different translation units (B vs. C)

warning: instance variable A declared with incompatible types in different translation units (B vs. C)

warning: non-type template parameter declared with incompatible types in different translation units (A vs. B)

warning:

class

instance

method B has a different number of parameters in different translation units (C vs. D)

warning:

class

instance

method B has a parameter with a different types in different translation units (C vs. D)

warning:

class

instance

method B has incompatible result types in different translation units (C vs. D)

warning:

class

instance

method B is variadic in one translation unit and not variadic in another

warning: property A is implemented with

@synthesize

@dynamic

in one translation but

@dynamic

@synthesize

in another translation unit

warning: property A declared with incompatible types in different translation units (B vs. C)

warning: class A has incompatible superclasses

warning: property A is synthesized to different ivars in different translation units (B vs. C)

warning: parameter kind mismatch; parameter is

not a

parameter pack

warning: type A has incompatible definitions in different translation units

warning: external variable A defined in multiple translation units

warning: external variable A declared with incompatible types in different translation units (B vs. C)

-Wold-style-cast ¶

Diagnostic text:

warning: use of old-style cast

-Wold-style-definition ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wopencl-unsupported-rgba ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: vector component name ‘A’ is a feature from OpenCL version 3.0 onwards

-Wopenmp ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wopenmp-51-extensions, -Wopenmp-clauses, -Wopenmp-loop-form, -Wopenmp-mapping, -Wopenmp-target, -Wsource-uses-openmp.

-Wopenmp-51-extensions ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: specifying OpenMP directives with [[]] is an OpenMP 5.1 extension

-Wopenmp-clauses ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: aligned clause will be ignored because the requested alignment is not a power of 2

warning: allocator with the ‘thread’ trait access has unspecified behavior on ‘A’ directive

warning: the context property ‘A’ is not valid for the context selector ‘B’ and the context set ‘C’; property ignored

warning: the context selector ‘A’ in the context set ‘B’ cannot have a score (’C’); score ignored

warning: the context selector ‘A’ is not valid for the context set ‘B’; selector ignored

warning: the context selector ‘A’ in context set ‘B’ requires a context property defined in parentheses; selector ignored

warning: the context

set

selector

property

‘B’ was used already in the same ‘omp declare variant’ directive;

set

selector

property

ignored

warning: ‘A’ is not a valid context property for the context selector ‘B’ and the context set ‘C’; property ignored

warning: ‘A’ is not a valid context selector for the context set ‘B’; selector ignored

warning: ‘A’ is not a valid context set in a `declare variant`; set ignored

warning: expected ‘A’ after the B; ‘A’ assumed

warning: expected identifier or string literal describing a context

set

selector

property

;

set

selector

property

skipped

warning: zero linear step (A

and other variables in clause

should probably be const)

warning: more than one ‘device_type’ clause is specified

warning: interop type ‘A’ cannot be specified more than once

warning: reserved locator ‘omp_all_memory’ cannot be specified more than once

warning: valid A clauses start with B;

token

tokens

will be ignored

warning: A clause should not be followed by arguments; tokens will be ignored

warning: allocate directive specifies

default

‘B’

allocator while previously used

default

‘D’

-Wopenmp-loop-form ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: initialization clause of OpenMP for loop is not in canonical form (‘var = init’ or ‘T var = init’)

warning: OpenMP loop iteration variable cannot have more than 64 bits size and will be narrowed

-Wopenmp-mapping ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: Type A is not trivially copyable and not guaranteed to be mapped correctly

-Wopenmp-target ¶

This diagnostic is enabled by default.

Also controls -Wopenmp-mapping.

Diagnostic text:

warning: OpenMP offloading target ‘A’ is similar to target ‘B’ already specified; will be ignored

warning: declaration marked as declare target after first use, it may lead to incorrect results

warning: declaration is not declared in any declare target region

-Woption-ignored ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: option ‘-ffine-grained-bitfield-accesses’ cannot be enabled together with a sanitizer; flag ignored

warning: -fjmc works only for ELF; option ignored

warning: A requires debug info. Use B or debug options that enable debugger’s stepping function; option ignored

warning: ignoring ‘A’ as it conflicts with that implied by ‘B’ (C)

warning: ‘A’ does not support ‘-B’; flag ignored

warning: ‘A’ does not support ‘-moutline’; flag ignored

warning: A requires HVX, use -mhvx/-mhvx= to enable it

warning: option ‘A’ was ignored by the B toolchain, using ‘-fPIC’

warning: The warning option ‘-A’ is not supported

warning: ignoring ‘-mlong-calls’ option as it is not currently supported with

the implicit usage of

-mabicalls

warning: the argument ‘A’ is not supported for option ‘B’. Mapping to ‘BC’

warning: ignoring ‘A’ option for offload arch ‘B’ as it is not currently supported there. Use it with an offload arch containing ‘C’ instead

warning: ignoring ‘A’ option as it is not currently supported for processor ‘B’

warning: ignoring ‘A’ option as it is not currently supported for target ‘B’

warning: ignoring ‘A’ option as it cannot be used with

implicit usage of

-mabicalls and the N64 ABI

warning: ignoring ‘-msmall-data-limit=’ with -mcmodel=large for -fpic or RV64

warning: /arm64EC has been overridden by specified target: A; option ignored

-Wordered-compare-function-pointers ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ordered comparison of function pointers (A and B)

-Wout-of-line-declaration ¶

This diagnostic is an error by default, but the flag -Wno-out-of-line-declaration can be used to disable the error.

Diagnostic text:

error: out-of-line declaration of a member must be a definition

-Wout-of-scope-function ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: use of out-of-scope declaration of A

whose type is not compatible with that of an implicit declaration

-Wover-aligned ¶

-Woverride-module ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: overriding the module target triple with A

-Woverriding-method-mismatch ¶

Diagnostic text:

warning: conflicting distributed object modifiers on parameter type in declaration of A

warning: conflicting parameter types in declaration of A

: B vs C

warning: conflicting distributed object modifiers on return type in declaration of A

warning: conflicting return type in declaration of A

: B vs C

warning: conflicting variadic declaration of method and its implementation

warning: conflicting parameter types in declaration of A: B vs C

warning: conflicting return type in declaration of A: B vs C

-Woverriding-t-option ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: overriding ‘A’ option with ‘B’

-Wpacked ¶

Also controls -Wpacked-non-pod.

Diagnostic text:

warning: packed attribute is unnecessary for A

-Wpacked-non-pod ¶

Diagnostic text:

warning: not packing field A as it is non-POD for the purposes of layout

-Wpadded ¶

Diagnostic text:

warning: padding

struct

interface

class

B with C

byte

bit

to align anonymous bit-field

warning: padding

struct

interface

class

B with C

byte

bit

to align E

warning: padding size of A with B

byte

bit

to alignment boundary

-Wparentheses ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wbitwise-conditional-parentheses, -Wbitwise-op-parentheses, -Wdangling-else, -Wlogical-not-parentheses, -Wlogical-op-parentheses, -Woverloaded-shift-op-parentheses, -Wparentheses-equality, -Wshift-op-parentheses.

Diagnostic text:

warning: using the result of an assignment as a condition without parentheses

warning: A has lower precedence than B; B will be evaluated first

warning: operator ‘?:’ has lower precedence than ‘A’; ‘A’ will be evaluated first

-Wparentheses-equality ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: equality comparison with extraneous parentheses

-Rpass ¶

Diagnostic text:

The text of this diagnostic is not controlled by Clang.

-Rpass-analysis ¶

Diagnostic text:

The text of this diagnostic is not controlled by Clang.

integral

constant expression; folding it to a constant is a GNU extension

warning: designated initializers are a C99 feature

warning: ISO C++ does not allow ‘main’ to be used by a program

warning: C++98 requires an accessible copy constructor for class C when binding a reference to a temporary; was

private

protected

warning: anonymous

struct

union

cannot be ‘B’

warning: ISO C++ requires the name after ‘::~’ to be found in the same scope as the name before ‘::~’

warning: ISO C++ considers this destructor name lookup to be ambiguous

warning: no viable constructor

copying variable

copying parameter

initializing template parameter

returning object

initializing statement expression result

throwing object

copying member subobject

copying array element

allocating object

copying temporary

initializing base subobject

initializing vector element

capturing value

of type B; C++98 requires a copy constructor when binding a reference to a temporary

warning: ISO C++ standards before C++17 do not allow new expression for type A to use list-initialization

warning: invoking a pointer to a ‘const &’ member function on an rvalue is a C++20 extension

warning: qualifier in explicit instantiation of A requires a template-id (a typedef is not permitted)

warning: a

function

block

declaration without a prototype is deprecated

in all versions of C

warning: static

function

variable

B is used in an inline function with external linkage

warning: ISO C forbids forward references to ‘enum’ types

warning: ISO C restricts enumerator values to range of ‘int’ (A is too

small

large

)

warning: initializer for aggregate is not a compile-time constant

warning: flexible array members are a C99 feature

warning: invalid application of ‘A’ to a function type

warning: invalid application of ‘A’ to a void type

warning: ISO C90 does not allow subscripting non-lvalue array

warning: ISO C forbids taking the address of an expression of type ‘void’

warning: ordered comparison between pointer and zero (A and B) is an extension

warning: equality comparison between function pointer and void pointer (A and B)

warning: ISO C does not support ‘++’/’–’ on complex integer type A

warning: ISO C does not support ‘~’ for complex conjugation of A

warning: complex numbers are an extension in a freestanding C99 implementation

warning: cast between pointer-to-function and pointer-to-object is an extension

warning: implicit conversion from array size expression of type A to

integral

enumeration

type C is a C++11 extension

warning:

assigning to A from B

assigning to different types

passing A to parameter of type B

passing to parameter of different type

returning A from a function with result type B

returning from function with different return type

converting A to type B

converting between types

initializing A with an expression of type B

initializing with expression of different type

sending A to parameter of type B

sending to parameter of different type

casting A to type B

casting between types

converts between void pointer and function pointer

warning: kernel function A is a member function; this may not be accepted by nvcc

warning: C99 forbids conditional expressions with only one void side

warning: C99 forbids casting nonscalar type A to the same type

warning: in-class initializer for static data member is not a constant expression; folding it to a constant is a GNU extension

warning: types declared in an anonymous

struct

union

are a Microsoft extension

warning: format specifies type A but the argument has

type

underlying type

warning: void

function

method

block

A should not return void expression

warning: mixing declarations and code is a C99 extension

warning:

qualifier in

static

array size

‘[*] ‘

is a C99 feature

warning: Clang permits use of type ‘double’ regardless pragma if ‘cl_khr_fp64’ is supported

warning: extra ‘;’

outside of a function

inside a B

inside instance variable list

after member function definition

warning: ‘__thread’ before ‘A’

warning: type-less parameter names in function declaration

warning: variable declaration in for loop is a C99-specific feature

warning: compound literals are a C99-specific feature

warning: commas at the end of enumerator lists are a C99-specific feature

warning: commas at the end of enumerator lists are a C++11 extension

warning: enumeration types with a fixed underlying type are a C++11 extension

warning: ‘A’ is a C99 extension

warning: use of GNU array range extension

warning: exception specification of ‘…’ is a Microsoft extension

warning: ‘nullptr’ is a C2x extension

warning: attributes on

a namespace

an enumerator

declaration are a C++17 extension

warning: [[]] attributes are a C++11 extension

warning: [[]] attributes are a C2x extension

warning: extern templates are a C++11 extension

warning: multi-line // comment

warning: // comments are not allowed in this language

warning: no newline at end of file

warning: use of non-standard escape character ‘\A’

warning: hexadecimal floating constants are a C99 feature

warning: hexadecimal floating literals are a C++17 feature

warning: #ident is a language extension

warning: #warning is a

C2x

C++23

extension

warning: comma operator in operand of #if

warning: __VA_ARGS__ can only appear in the expansion of a C99 variadic macro

warning: variadic macros are a C99 feature

warning: named variadic macros are a GNU extension

warning: empty macro arguments are a C99 feature

warning: variadic macros are a Clang extension in OpenCL

warning: C requires #line number to be less than A, allowed as extension

warning: macro expansion producing ‘defined’ has undefined behavior

warning: use of an empty initializer is a C2x extension

warning: duplicate ‘A’ declaration specifier

warning: ‘enable_if’ is a clang extension

warning: ‘diagnose_if’ is a clang extension

-Wpedantic-core-features ¶

Diagnostic text:

warning: A is a core feature in

OpenCL C

function call

parameter

‘B’ will evaluate to ‘true’ on first encounter

warning: address of

function

array

‘B’ will always evaluate to ‘true’

-Wpointer-compare ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: comparing a pointer to a null character constant; did you mean to compare to

NULL

(void *)0

-Wpointer-integer-compare ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: comparison between pointer and integer (A and B)

-Wpointer-sign ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

assigning to A from B

assigning to different types

passing A to parameter of type B

passing to parameter of different type

returning A from a function with result type B

returning from function with different return type

converting A to type B

converting between types

initializing A with an expression of type B

initializing with expression of different type

sending A to parameter of type B

sending to parameter of different type

casting A to type B

casting between types

converts between pointers to integer types

with different sign

where one is of the unique plain ‘char’ type and the other is not

-Wpointer-to-enum-cast ¶

This diagnostic is enabled by default.

Also controls -Wvoid-pointer-to-enum-cast.

Diagnostic text:

warning: cast to smaller integer type B from A

-Wpointer-to-int-cast ¶

This diagnostic is enabled by default.

Also controls -Wpointer-to-enum-cast, -Wvoid-pointer-to-int-cast.

Diagnostic text:

warning: cast to smaller integer type B from A

-Wpointer-type-mismatch ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: pointer type mismatch

(A and B)

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wpragma-pack-suspicious-include.

Diagnostic text:

warning: the current #pragma pack alignment value is modified in the included file

warning: unterminated ‘#pragma pack (push, …)’ at end of file

-Wpragma-pack-suspicious-include ¶

Diagnostic text:

warning: non-default #pragma pack value changes the alignment of struct or union members in the included file

-Wpragma-system-header-outside-header ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: #pragma system_header ignored in main file

-Wpragmas ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wignored-pragmas, -Wpragma-clang-attribute, -Wpragma-pack, -Wunknown-pragmas.

Diagnostic text:

warning: Setting the floating point evaluation method to `source` on a target without SSE is not supported.

warning: #pragma redefine_extname is applicable to external C declarations only; not applied to

function

variable

-Wpre-c++14-compat ¶

Diagnostic text:

warning: use of this statement in a constexpr

function

constructor

is incompatible with C++ standards before C++14

warning: multiple return statements in constexpr function is incompatible with C++ standards before C++14

warning: constexpr function with no return statements is incompatible with C++ standards before C++14

warning: variable declaration in a constexpr

function

constructor

is incompatible with C++ standards before C++14

warning: type definition in a constexpr

function

constructor

is incompatible with C++ standards before C++14

warning: ‘decltype(auto)’ type specifier is incompatible with C++ standards before C++14

warning: return type deduction is incompatible with C++ standards before C++14

warning: digit separators are incompatible with C++ standards before C++14

warning: generic lambdas are incompatible with C++11

warning: initialized lambda captures are incompatible with C++ standards before C++14

warning: variable templates are incompatible with C++ standards before C++14

-Wpre-c++14-compat-pedantic ¶

Controls -Wc++98-c++11-compat-binary-literal, -Wpre-c++14-compat.

-Wpre-c++17-compat ¶

Diagnostic text:

warning: class template argument deduction is incompatible with C++ standards before C++17

; for compatibility, use explicit type name B

warning: constexpr if is incompatible with C++ standards before C++17

warning: constexpr on lambda expressions is incompatible with C++ standards before C++17

warning: decomposition declarations are incompatible with C++ standards before C++17

warning: pack fold expression is incompatible with C++ standards before C++17

warning:

switch

initialization statements are incompatible with C++ standards before C++17

warning: inline variables are incompatible with C++ standards before C++17

warning: nested namespace definition is incompatible with C++ standards before C++17

warning: by value capture of ‘*this’ is incompatible with C++ standards before C++17

warning: ‘static_assert’ with no message is incompatible with C++ standards before C++17

warning: non-type template parameters declared with A are incompatible with C++ standards before C++17

warning: template template parameter using ‘typename’ is incompatible with C++ standards before C++17

warning: unicode literals are incompatible with C++ standards before C++17

warning: default scope specifier for attributes is incompatible with C++ standards before C++17

warning: use of multiple declarators in a single using declaration is incompatible with C++ standards before C++17

warning: pack expansion using declaration is incompatible with C++ standards before C++17

warning: ‘begin’ and ‘end’ returning different types (A and B) is incompatible with C++ standards before C++17

-Wpre-c++17-compat-pedantic ¶

Also controls -Wpre-c++17-compat.

Diagnostic text:

warning: attributes on

a namespace

an enumerator

declaration are incompatible with C++ standards before C++17

warning: hexadecimal floating literals are incompatible with C++ standards before C++17

-Wpre-c++20-compat ¶

Diagnostic text:

warning: use of function template name with no prior function template declaration in function call with explicit template arguments is incompatible with C++ standards before C++20

warning: default member initializer for bit-field is incompatible with C++ standards before C++20

warning: captured structured bindings are incompatible with C++ standards before C++20

warning: use of this statement in a constexpr

function

constructor

is incompatible with C++ standards before C++20

warning: constexpr constructor that does not initialize all members is incompatible with C++ standards before C++20

warning: function try block in constexpr

function

constructor

is incompatible with C++ standards before C++20

warning: uninitialized variable in a constexpr

function

constructor

is incompatible with C++ standards before C++20

warning: constexpr union constructor that does not initialize any member is incompatible with C++ standards before C++20

warning: virtual constexpr functions are incompatible with C++ standards before C++20

warning: decomposition declaration declared

‘B’

with ‘B’ specifiers

is incompatible with C++ standards before C++20

warning: defaulted comparison operators are incompatible with C++ standards before C++20

warning: explicitly defaulting this

default constructor

copy constructor

move constructor

copy assignment operator

move assignment operator

destructor

with a type different from the implicit type is incompatible with C++ standards before C++20

warning: explicit capture of ‘this’ with a capture default of ‘=’ is incompatible with C++ standards before C++20

warning: explicit(bool) is incompatible with C++ standards before C++20

warning: range-based for loop initialization statements are incompatible with C++ standards before C++20

warning: initialized lambda capture packs are incompatible with C++ standards before C++20

warning: inline nested namespace definition is incompatible with C++ standards before C++20

warning:

default construction

assignment

of lambda is incompatible with C++ standards before C++20

warning: explicit template parameter list for lambdas is incompatible with C++ standards before C++20

warning: passing no argument for the ‘…’ parameter of a variadic macro is incompatible with C++ standards before C++20

warning: ‘<=>’ operator is incompatible with C++ standards before C++20

warning: non-type template parameter of type A is incompatible with C++ standards before C++20

warning: ‘char8_t’ type specifier is incompatible with C++ standards before C++20

warning: member using declaration naming a non-member enumerator is incompatible with C++ standards before C++20

warning: member using declaration naming non-class ‘A’ enumerator is incompatible with C++ standards before C++20

warning: using declaration naming a scoped enumerator is incompatible with C++ standards before C++20

warning: using enum declaration is incompatible with C++ standards before C++20

-Wpre-c++20-compat-pedantic ¶

Also controls -Wpre-c++20-compat.

Diagnostic text:

warning: designated initializers are incompatible with C++ standards before C++20

warning: invoking a pointer to a ‘const &’ member function on an rvalue is incompatible with C++ standards before C++20

-Wpre-c++23-compat ¶

Diagnostic text:

warning: overloaded A with

a defaulted

more than one

parameter is a C++23 extension

warning: alias declaration in this context is incompatible with C++ standards before C++23

warning: ‘auto’ as a functional-style cast is incompatible with C++ standards before C++23

warning: consteval if is incompatible with C++ standards before C++23

warning: use of this statement in a constexpr

function

constructor

is incompatible with C++ standards before C++23

warning: definition of a

static variable

thread_local variable

variable of non-literal type

in a constexpr

function

constructor

is incompatible with C++ standards before C++23

warning:

an attribute specifier sequence

in this position is incompatible with C++ standards before C++23

warning: label at end of compound statement is incompatible with C++ standards before C++23

warning: declaring overloaded A as ‘static’ is incompatible with C++ standards before C++23

warning: ‘size_t’ suffix for literals is incompatible with C++ standards before C++23

warning: static lambdas are incompatible with C++ standards before C++23

warning: defaulted definition of

<ERROR>

equality

three-way

equality

relational

comparison operator

three-way comparison operator

that is declared

constexpr

consteval

but

for which the corresponding implicit ‘operator==’

invokes a non-constexpr comparison function is incompatible with C++ standards before C++23

warning: use of a ‘#

elifdef

elifndef

‘ directive is incompatible with C++ standards before C++23

warning: #warning is incompatible with C++ standards before C++23

warning:

delimited

named

escape sequences are incompatible with C++ standards before C++23

-Wpre-c++23-compat-pedantic ¶

Synonym for -Wpre-c++23-compat.

-Wpre-c++26-compat ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wpre-c++26-compat-pedantic ¶

Synonym for -Wpre-c++26-compat.

-Wpre-c++2c-compat ¶

Synonym for -Wpre-c++26-compat.

-Wpre-c++2c-compat-pedantic ¶

Synonym for -Wpre-c++26-compat-pedantic.

-Wpre-c2x-compat ¶

Diagnostic text:

warning: ‘_BitInt’ suffix for literals is incompatible with C standards before C2x

warning: digit separators are incompatible with C standards before C2x

warning: use of an empty initializer is incompatible with C standards before C2x

warning: ‘A’ is incompatible with C standards before C2x

warning: label at end of compound statement is incompatible with C standards before C2x

warning: universal character name referring to a control character is incompatible with C standards before C2x

warning: specifying character ‘A’ with a universal character name is incompatible with C standards before C2x

warning: use of a ‘#

elifdef

elifndef

‘ directive is incompatible with C standards before C2x

warning: #warning is incompatible with C standards before C2x

warning: ‘…’ as the only parameter of a function is incompatible with C standards before C2x

warning: ‘_Static_assert’ with no message is incompatible with C standards before C2x

warning: [[]] attributes are incompatible with C standards before C2x

-Wpre-c2x-compat-pedantic ¶

Synonym for -Wpre-c2x-compat.

This diagnostic is enabled by default.

Diagnostic text:

warning: expected canonical name for private module ‘A’

warning: private submodule ‘A’ in private module map, expected top-level module

warning: module ‘A’ already re-exported as ‘B’

warning: no submodule named A in module ‘B’; using top level ‘C’

-Wprofile-instr-missing ¶

Diagnostic text:

warning: profile data may be incomplete: of A function

, B

has

have

no data

-Wprofile-instr-out-of-date ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: profile data may be out of date: of A function

, B

has

have

mismatched data that will be ignored

-Wprofile-instr-unprofiled ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: no profile data available for file “A”

-Wproperty-access-dot-syntax ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: property A not found on object of type B; did you mean to access property C?

-Wproperty-attribute-mismatch ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: property attribute in class extension does not match the primary class

warning: ‘B’ attribute on property A does not match the property inherited from C

warning: getter name mismatch between property redeclaration (B) and its original declaration (A)

warning: attribute ‘readonly’ of property A restricts attribute ‘readwrite’ of property inherited from B

-Wprotocol ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: method A in protocol B not implemented

-Wprotocol-property-synthesis-ambiguity ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: property

of type B

with attribute ‘B’

without attribute ‘B’

with getter B

with setter B

was selected for synthesis

-Wpsabi ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: AVX vector

return

argument

of type B without ‘C’ enabled changes the ABI

-Wqualified-void-return-type ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: function cannot return qualified void type A

-Wquoted-include-in-framework-header ¶

Diagnostic text:

warning: double-quoted include “A” in framework header, expected angle-bracketed instead

-Wrange-loop-analysis ¶

Controls -Wrange-loop-bind-reference, -Wrange-loop-construct.

-Wrange-loop-bind-reference ¶

Diagnostic text:

warning: loop variable A binds to a temporary value produced by a range of type B

-Wrange-loop-construct ¶

Diagnostic text:

warning: loop variable A

-Wredeclared-class-member ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: class member cannot be redeclared

-Wredundant-consteval-if ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: consteval if is always true in an

unevaluated

immediate

context

-Wredundant-decls ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wredundant-move ¶

-Wreorder ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wreorder-ctor, -Wreorder-init-list.

-Wreorder-ctor ¶

Diagnostic text:

warning:

field

base class

B will be initialized after

field

base

warning: initializer order does not match the declaration order

-Wreorder-init-list ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ISO C++ requires field designators to be specified in declaration order; field B will be initialized after field A

-Wrequires-super-attribute ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: A attribute cannot be applied to

methods in protocols

dealloc

-Wreserved-id-macro ¶

Synonym for -Wreserved-macro-identifier.

-Wreserved-identifier ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wreserved-macro-identifier, -Wreserved-module-identifier, -Wuser-defined-literals.

Diagnostic text:

warning: identifier A is reserved because

<ERROR>

it starts with ‘_’ at global scope

it starts with ‘_’ and has C language linkage

it starts with ‘__’

it starts with ‘_’ followed by a capital letter

it contains ‘__’

-Wreserved-macro-identifier ¶

Diagnostic text:

warning: macro name is a reserved identifier

-Wreserved-module-identifier ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: A is a reserved name for a module

-Wreserved-user-defined-literal ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wc++11-compat-reserved-user-defined-literal.

Diagnostic text:

warning: invalid suffix on literal; C++11 requires a space between literal and identifier

error: invalid suffix on literal; C++11 requires a space between literal and identifier

-Wrestrict-expansion ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: macro A has been marked as unsafe for use in headers

: C

-Wretained-language-linkage ¶

Diagnostic text:

warning: friend function A retaining previous language linkage is an extension

-Wreturn-local-addr ¶

Synonym for -Wreturn-stack-address.

-Wreturn-stack-address ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: returning address of label, which is local

warning: returning

address of

reference to

local temporary object

warning:

address of

reference to

stack memory associated with

local variable

parameter

B returned

-Wreturn-std-move ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wreturn-type ¶

This diagnostic is enabled by default.

Also controls -Wreturn-type-c-linkage.

Diagnostic text:

error:

void function

void method

constructor

destructor

A should not return a value

error: non-void

function

method

A should return a value

warning: non-void coroutine does not return a value

warning: non-void function does not return a value

warning: non-void lambda does not return a value

warning: non-void coroutine does not return a value in all control paths

warning: non-void function does not return a value in all control paths

warning: non-void lambda does not return a value in all control paths

error: non-void

function

method

A should return a value

-Wreturn-type-c-linkage ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: A has C-linkage specified, but returns user-defined type B which is incompatible with C

warning: A has C-linkage specified, but returns incomplete type B which could be incompatible with C

-Wrewrite-not-bool ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ISO C++20 requires return type of selected ‘operator==’ function for rewritten ‘B’ comparison to be ‘bool’, not A

-Rround-trip-cc1-args ¶

Diagnostic text:

remark: generated arguments #A in round-trip: B

-Wrtti ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: dynamic_cast will not work since RTTI data is disabled by

-fno-rtti-data

/GR-

warning: typeid will not work since RTTI data is disabled by

-fno-rtti-data

/GR-

-Rsanitize-address ¶

Diagnostic text:

remark: -fsanitize-address-field-padding applied to A

remark: -fsanitize-address-field-padding ignored for A because it

is not C++

is packed

is a union

is trivially copyable

has trivial destructor

is standard layout

is in a ignorelisted file

is ignorelisted

-Wsarif-format-unstable ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: diagnostic formatting in SARIF mode is currently unstable

-Rsearch-path-usage ¶

Diagnostic text:

remark: search path used: ‘A’

-Wsection ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: section attribute is specified on redeclared variable

warning: duplicate code segment specifiers

warning:

codeseg

section

does not match previous declaration

-Wselector ¶

Also controls -Wselector-type-mismatch.

Diagnostic text:

warning: no method with selector A is implemented in this translation unit

-Wselector-type-mismatch ¶

Diagnostic text:

warning: several methods with selector A of mismatched types are found for the @selector expression

-Wself-assign ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wself-assign-field, -Wself-assign-overloaded.

Diagnostic text:

warning: explicitly assigning value of variable of type A to itself

; did you mean to assign to member C?

-Wself-assign-field ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: assigning

field

instance variable

to itself

-Wself-assign-overloaded ¶

Diagnostic text:

warning: explicitly assigning value of variable of type A to itself

; did you mean to assign to member C?

-Wself-move ¶

Diagnostic text:

warning: explicitly moving variable of type A to itself

; did you mean to move to member C?

-Wsemicolon-before-method-body ¶

Diagnostic text:

warning: semicolon before method body is ignored

-Wsentinel ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: missing sentinel in

function call

method dispatch

block call

warning: not enough variable arguments in A declaration to fit a sentinel

-Wsequence-point ¶

Synonym for -Wunsequenced.

-Wserialized-diagnostics ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: unable to open file A for serializing diagnostics (B)

warning: Received warning after diagnostic serialization teardown was underway: A

warning: unable to merge a subprocess’s serialized diagnostics

-Wshadow ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wshadow-field-in-constructor-modified, -Wshadow-ivar.

Diagnostic text:

warning: declaration shadows a

local variable

variable in C

static data member of C

field of C

-Wshift-negative-value ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: shifting a negative signed value is undefined

-Wshift-op-parentheses ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: operator ‘A’ has lower precedence than ‘B’; ‘B’ will be evaluated first

-Wshift-overflow ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: signed shift result (A) requires B bits to represent, but C only has D bits

-Wshift-sign-overflow ¶

Diagnostic text:

warning: signed shift result (A) sets the sign bit of the shift expression’s type (B) and becomes negative

-Wshorten-64-to-32 ¶

Diagnostic text:

warning: implicit conversion loses integer precision: A to B

-Wsign-compare ¶

Diagnostic text:

warning: comparison of integers of different signs: A and B

-Wsign-conversion ¶

Diagnostic text:

warning: implicit conversion changes signedness: A to B

warning: operand of ? changes signedness: A to B

warning: the resulting value is always non-negative after implicit conversion

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘A’ call operates on objects of type B while the size is based on a different type C

warning: argument to ‘sizeof’ in A call is the same pointer type B as the

destination

source

; expected D or an explicit length

-Wslash-u-filename ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘/UA’ treated as the ‘/U’ option

-Wslh-asm-goto ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: speculative load hardening does not protect functions with asm goto

-Rsloc-usage ¶

This diagnostic is enabled by default.

Diagnostic text:

remark: source manager location address space usage:

-Wsometimes-uninitialized ¶

Diagnostic text:

warning: variable A is

used

captured

uninitialized whenever

‘D’ condition is

true

false

‘D’ loop

is entered

exits because its condition is false

‘D’ loop

condition is true

exits because its condition is false

switch D is taken

its declaration is reached

D is called

-Wsource-mgr ¶

This diagnostic is enabled by default.

Diagnostic text:

The text of this diagnostic is not controlled by Clang.

-Wsource-uses-openmp ¶

Some of the diagnostics controlled by this flag are enabled by default.

Diagnostic text:

warning: ‘#pragma omp declare variant’ cannot be applied to the function that was defined already; the original function might be used

warning: ‘#pragma omp declare variant’ cannot be applied for function after first usage; the original function might be used

warning: variant function in ‘#pragma omp declare variant’ is itself marked as ‘#pragma omp declare variant’

warning: score expressions in the OpenMP context selector need to be constant; A is not and will be ignored

warning: OpenMP only allows an ordered construct with the simd clause nested in a simd construct

warning: expected ‘#pragma omp end declare target’ at end of file to match ‘#pragma omp A’

warning: unexpected ‘#pragma omp …’ in program

warning: isa trait ‘A’ is not known to the current target; verify the spelling or consider restricting the context selector with the ‘arch’ selector further

-Wspir-compat ¶

Diagnostic text:

warning: sampler initializer has invalid A bits

-Wspirv-compat ¶

Synonym for -Wspir-compat.

-Wstack-exhausted ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: stack nearly exhausted; compilation time may suffer, and crashes due to stack overflow are likely

-Wstack-protector ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: unable to protect inline asm that clobbers stack pointer against stack clash

-Wstatic-float-init ¶

This diagnostic is enabled by default.

Also controls -Wgnu-static-float-init.

Diagnostic text:

error: in-class initializer for static data member of type A requires ‘constexpr’ specifier

-Wstatic-in-inline ¶

Some of the diagnostics controlled by this flag are enabled by default.

Diagnostic text:

warning: static

function

variable

B is used in an inline function with external linkage

warning: static

function

variable

B is used in an inline function with external linkage

-Wstatic-inline-explicit-instantiation ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ignoring ‘

static

inline

‘ keyword on explicit template instantiation

-Wstatic-local-in-inline ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: non-constant static local variable in inline function may be different in different files

-Wstatic-self-init ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: static variable A is suspiciously used within its own initialization

-Wstdlibcxx-not-found ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: include path for libstdc++ headers not found; pass ‘-stdlib=libc++’ on the command line to use the libc++ standard library instead

-Wstrict-aliasing ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wstrict-aliasing=0 ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wstrict-aliasing=1 ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wstrict-aliasing=2 ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wstrict-overflow ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wstrict-overflow=0 ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wstrict-overflow=1 ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wstrict-overflow=2 ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wstrict-overflow=3 ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wstrict-overflow=4 ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wstrict-overflow=5 ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wstrict-potentially-direct-selector ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wpotentially-direct-selector.

Diagnostic text:

warning: @selector expression formed with potentially direct selector A

-Wstrict-prototypes ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wdeprecated-non-prototype.

Diagnostic text:

warning: a

function

block

declaration without a prototype is deprecated

in all versions of C

-Wstrict-selector-match ¶

Diagnostic text:

warning: multiple methods named A found

-Wstring-compare ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: result of comparison against

a string literal

@encode

is unspecified (use an explicit string comparison function instead)

-Wstring-concatenation ¶

Diagnostic text:

warning: suspicious concatenation of string literals in an array initialization; did you mean to separate the elements with a comma?

This diagnostic is enabled by default.

Diagnostic text:

warning: the value of the size argument in ‘strncat’ is too large, might lead to a buffer overflow

warning: size argument in ‘strncat’ call appears to be size of the source

warning: the value of the size argument to ‘strncat’ is wrong

-Wsuggest-destructor-override ¶

Diagnostic text:

warning: A overrides a destructor but is not marked ‘override’

-Wsuggest-override ¶

Diagnostic text:

warning: A overrides a member function but is not marked ‘override’

-Wsuper-class-method-mismatch ¶

Diagnostic text:

warning: method parameter type

A does not match super class method parameter type B

does not match super class method parameter type

-Wsuspicious-bzero ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ‘size’ argument to bzero is ‘0’

-Wsuspicious-memaccess ¶

This diagnostic is enabled by default.

Controls -Wdynamic-class-memaccess, -Wmemset-transposed-args, -Wnontrivial-memaccess, -Wsizeof-pointer-memaccess, -Wsuspicious-bzero.

-Wswift-name-attribute ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: A attribute cannot be applied to this declaration

warning: A attribute cannot be applied to a

function

method

with no parameters

warning: A attribute argument must be a string literal specifying a Swift function name

warning: A attribute for getter must not have any parameters besides ‘self:’

warning: A attribute has invalid identifier for the

base

context

parameter

name

warning: A attribute is missing parameter label clause

warning: A attribute cannot specify more than one ‘self:’ parameter

warning: too

few

many

parameters in the signature specified by the B attribute (expected C; got D)

warning: A attribute for setter must have one parameter for new value

warning: A attribute for ‘subscript’ getter cannot have a ‘newValue:’ parameter

warning: A attribute for ‘subscript’ must

be a getter or setter

have at least one parameter

have a ‘self:’ parameter

warning: A attribute for ‘subscript’ setter cannot have multiple ‘newValue:’ parameters

warning: A attribute for ‘subscript’ setter must have a ‘newValue:’ parameter

-Wswitch ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: overflow converting case value to switch condition type (A to B)

warning:

enumeration value B not handled in switch

enumeration values B and C not handled in switch

enumeration values B, C, and D not handled in switch

A enumeration values not handled in switch: B, C, D…

warning: case value not in enumerated type A

-Wswitch-bool ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: switch condition has boolean value

-Wswitch-default ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wswitch-enum ¶

Diagnostic text:

warning:

enumeration value B not explicitly handled in switch

enumeration values B and C not explicitly handled in switch

enumeration values B, C, and D not explicitly handled in switch

A enumeration values not explicitly handled in switch: B, C, D…

-Wsync-alignment ¶

This diagnostic is enabled by default.

Diagnostic text:

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wtautological-bitwise-compare, -Wtautological-constant-compare, -Wtautological-objc-bool-compare, -Wtautological-overlap-compare, -Wtautological-pointer-compare, -Wtautological-undefined-compare.

Diagnostic text:

warning:

aligning a value

the result of checking whether a value is aligned

to 1 byte is

a no-op

always true

warning:

self-

array

comparison always evaluates to

a constant

true

false

‘std::strong_ordering::equal’

-Wtautological-constant-compare ¶

This diagnostic is enabled by default.

Also controls -Wtautological-constant-out-of-range-compare.

Diagnostic text:

warning: converting the result of ‘?:’ with integer constants to a boolean always evaluates to ‘true’

warning: converting the result of ‘<<’ to a boolean always evaluates to

false

true

warning: result of comparison of

constant A

true

false

with

expression of type C

boolean expression

is always E

-Wtautological-constant-in-range-compare ¶

Controls -Wtautological-value-range-compare, -Wtype-limits.

-Wtautological-constant-out-of-range-compare ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: result of comparison of

constant A

true

false

with

expression of type C

boolean expression

is always E

-Wtautological-objc-bool-compare ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: result of comparison of constant A with expression of type ‘BOOL’ is always B, as the only well defined values for ‘BOOL’ are YES and NO

-Wtautological-overlap-compare ¶

Diagnostic text:

warning: overlapping comparisons always evaluate to

false

true

-Wtautological-pointer-compare ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: comparison of nonnull

function call

parameter

‘B’

not

equal to a null pointer is ‘

true

false

‘ on first encounter

warning: comparison of

address of

function

array

‘B’

-Wtautological-unsigned-zero-compare ¶

Diagnostic text:

warning: result of comparison of

unsigned expression

is always E

-Wtautological-value-range-compare ¶

Diagnostic text:

warning: result of comparison of

B-bit

signed

unsigned

value

B-bit

signed

unsigned

value

is always F

-Wtcb-enforcement ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: calling A is a violation of trusted computing base ‘B’

-Wtentative-definition-incomplete-type ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: tentative definition of variable with internal linkage has incomplete non-array type A

-Wthread-safety ¶

Controls -Wthread-safety-analysis, -Wthread-safety-attributes, -Wthread-safety-precise, -Wthread-safety-reference.

-Wthread-safety-analysis ¶

Diagnostic text:

warning: A ‘B’ must be acquired before ‘C’

warning: Cycle in acquired_before/after dependencies, starting with ‘A’

warning: cannot resolve lock expression

warning: acquiring A ‘B’ that is already held

warning: expecting A ‘B’ to be held at start of each loop

warning: expecting A ‘B’ to be held at the end of function

warning: cannot call function ‘B’ while A ‘C’ is held

warning: calling function B requires holding A

‘C’

‘C’ exclusively

warning: calling function A requires negative capability ‘B’

warning: A ‘B’ is acquired exclusively and shared in the same scope

warning: A ‘B’ is not held on every path through here

warning: A ‘B’ is still held at the end of function

warning: releasing A ‘B’ that was not held

warning: releasing A ‘B’ using

shared

exclusive

access, expected

shared

exclusive

access

warning:

reading

writing

the value pointed to by A requires holding

any mutex

any mutex exclusively

warning:

reading

writing

the value pointed to by B requires holding A

‘C’

‘C’ exclusively

warning:

reading

writing

variable A requires holding

any mutex

any mutex exclusively

warning:

reading

writing

variable B requires holding A

‘C’

‘C’ exclusively

-Wthread-safety-attributes ¶

Diagnostic text:

warning: A attribute requires arguments whose type is annotated with ‘capability’ attribute; type here is B

warning: A attribute can only be applied in a context annotated with ‘capability’ attribute

warning: A only applies to pointer types; type here is B

warning: ignoring A attribute because its argument is invalid

warning: A attribute without capability arguments refers to ‘this’, but B isn’t annotated with ‘capability’ or ‘scoped_lockable’ attribute

warning: A attribute without capability arguments can only be applied to non-static methods of a class

-Wthread-safety-beta ¶

Diagnostic text:

warning: thread safety beta warning

-Wthread-safety-negative ¶

Diagnostic text:

warning: acquiring A ‘B’ requires negative capability ‘C’

-Wthread-safety-precise ¶

Diagnostic text:

warning: calling function B requires holding A

‘C’

‘C’ exclusively

warning:

reading

writing

the value pointed to by B requires holding A

‘C’

‘C’ exclusively

warning:

reading

writing

variable B requires holding A

‘C’

‘C’ exclusively

-Wthread-safety-reference ¶

Diagnostic text:

warning: passing variable B by reference requires holding A

‘C’

‘C’ exclusively

warning: passing the value that B points to by reference requires holding A

‘C’

‘C’ exclusively

-Wthread-safety-verbose ¶

Diagnostic text:

warning: thread safety verbose warning

-Wtrigraphs ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: trigraph converted to ‘A’ character

warning: trigraph ends block comment

warning: trigraph ignored

warning: ignored trigraph would end block comment

-Wtype-limits ¶

Controls -Wtautological-type-limit-compare, -Wtautological-unsigned-char-zero-compare, -Wtautological-unsigned-enum-zero-compare, -Wtautological-unsigned-zero-compare.

-Wtype-safety ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: specified A type tag requires a null pointer

warning: argument type A doesn’t match specified B type tag

that requires D

warning: this type tag was not designed to be used with this function

-Wtypedef-redefinition ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: redefinition of typedef A is a C11 feature

-Wtypename-missing ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: missing ‘typename’ prior to dependent type name ‘AB’

-Wunable-to-open-stats-file ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: unable to open statistics output file ‘A’: ‘B’

Diagnostic text:

warning: A is not defined, evaluates to 0

-Wundef-prefix ¶

Diagnostic text:

warning: A is not defined, evaluates to 0

-Wundefined-bool-conversion ¶

This diagnostic is enabled by default.

variable

B because its type does not have linkage

-Wundefined-reinterpret-cast ¶

Diagnostic text:

warning: dereference of type B that was reinterpret_cast from type A has undefined behavior

warning: reinterpret_cast from A to B has undefined behavior

-Wundefined-var-template ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: instantiation of variable A required here, but no definition is available

This diagnostic is enabled by default.

Diagnostic text:

warning: A is only available on B C or newer

-Wunicode ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: empty delimited universal character name; treating as ‘\’ ‘A’ ‘{’ ‘}’

warning: incomplete delimited universal character name; treating as ‘\’ ‘A’ ‘{’ identifier

warning: incomplete universal character name; treating as ‘\’ followed by identifier

warning: \A used with no following hex digits; treating as ‘\’ followed by identifier

warning: universal character name refers to a surrogate character

warning: universal character names are only valid in C99 or C++; treating as ‘\’ followed by identifier

warning: universal character names are only valid in C99 or C++

-Wunicode-homoglyph ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: treating Unicode character <U+A> as an identifier character rather than as ‘B’ symbol

-Wunicode-whitespace ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: treating Unicode character as whitespace

-Wunicode-zero-width ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: identifier contains Unicode character <U+A> that is invisible in some environments

-Wuninitialized ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wsometimes-uninitialized, -Wstatic-self-init, -Wuninitialized-const-reference.

Diagnostic text:

warning: base class A is uninitialized when used here to access B

warning: field A is uninitialized when used here

warning: reference A is not yet bound to a value when used here

warning: block pointer variable A is

uninitialized

null

when captured by block

warning: variable A is uninitialized when used within its own initialization

warning: reference A is not yet bound to a value when used within its own initialization

warning: variable A is uninitialized when

used here

captured by block

-Wuninitialized-const-reference ¶

Diagnostic text:

warning: variable A is uninitialized when passed as a const reference argument here

-Wunknown-argument ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: joined argument treated as ‘A’; did you mean ‘B’?

warning: unknown argument ignored in clang-cl: ‘A’

warning: unknown argument ignored in clang-cl ‘A’; did you mean ‘B’?

-Wunknown-assumption ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: unknown assumption string ‘A’; attribute is potentially ignored

-Wunknown-attributes ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: unknown attribute A ignored

-Wunknown-cuda-version ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: CUDA versionA is newer than the latest

partially

supported version C

warning: CUDA version A is only partially supported

-Wunknown-directives ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: invalid preprocessing directive

, did you mean ‘#B’?

-Wunknown-escape-sequence ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: unknown escape sequence ‘\A’

-Wunknown-pragmas ¶

Some of the diagnostics controlled by this flag are enabled by default.

Diagnostic text:

warning: expected ‘ON’ or ‘OFF’ or ‘DEFAULT’ in pragma

warning: expected end of directive in pragma

warning: unknown pragma in STDC namespace

warning: pragma diagnostic pop could not pop, no matching push

warning: pragma diagnostic expected ‘error’, ‘warning’, ‘ignored’, ‘fatal’, ‘push’, or ‘pop’

warning: pragma diagnostic expected option name (e.g. “-Wundef”)

warning: unexpected token in pragma diagnostic

warning: #pragma execution_character_set expected ‘A’

warning: #pragma execution_character_set invalid value ‘A’, only ‘UTF-8’ is supported

warning: #pragma execution_character_set expected ‘push’ or ‘pop’

warning: unknown pragma ignored

warning: pragma include_alias expected ‘A’

warning: pragma include_alias expected include filename

warning: angle-bracketed include <A> cannot be aliased to double-quoted include “B”

warning: double-quoted include “A” cannot be aliased to angle-bracketed include <B>

warning: #pragma warning expected ‘A’

warning: #pragma warning expected a warning number

warning: #pragma warning(push, level) requires a level between 0 and 4

warning: #pragma warning expected ‘push’, ‘pop’, ‘default’, ‘disable’, ‘error’, ‘once’, ‘suppress’, 1, 2, 3, or 4

warning: pragma STDC FENV_ROUND is not supported

-Wunknown-sanitizers ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: unknown sanitizer ‘A’ ignored

-Wunknown-warning-option ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: unknown warning group ‘A’, ignored

warning: unknown

warning

remark

option ‘B’

; did you mean ‘D’?

warning: unknown A warning specifier: ‘B’

-Wunnamed-type-template-args ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wc++98-compat-unnamed-type-template-args.

Diagnostic text:

warning: template argument uses unnamed type

-Wunneeded-internal-declaration ¶

Diagnostic text:

warning:

function

variable

B is not needed and will not be emitted

warning: ‘static’ function A declared in header file should be declared ‘static inline’

-Wunneeded-member-function ¶

Diagnostic text:

warning: member function A is not needed and will not be emitted

-Wunqualified-std-cast-call ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: unqualified call to ‘A’

-Wunreachable-code ¶

Some of the diagnostics controlled by this flag are enabled by default.

Also controls -Wunreachable-code-fallthrough, -Wunreachable-code-generic-assoc, -Wunreachable-code-loop-increment.

Diagnostic text:

warning:

unsafe pointer operation

unsafe pointer arithmetic

unsafe buffer access

This diagnostic is enabled by default.

Diagnostic text:

warning: ignoring ‘-mcompact-branches=’ option because the ‘A’ architecture does not support it

-Wunsupported-dll-base-class-template ¶

Diagnostic text:

warning: propagating dll attribute to

already instantiated

explicitly specialized

base class template without dll attribute is not supported

-Wunsupported-floating-point-opt ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: overriding currently unsupported use of floating point exceptions on this target

warning: overriding currently unsupported rounding mode on this target

-Wunsupported-friend ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: dependent nested name specifier ‘A’ for friend template declaration is not supported; ignoring this friend declaration

warning: dependent nested name specifier ‘A’ for friend class declaration is not supported; turning off access control for B

-Wunsupported-gpopt ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ignoring ‘-mgpopt’ option as it cannot be used with

the implicit usage of

-mabicalls

-Wunsupported-nan ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ignoring ‘-mnan=2008’ option because the ‘A’ architecture does not support it

warning: ignoring ‘-mnan=legacy’ option because the ‘A’ architecture does not support it

-Wunsupported-target-opt ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: debug information option ‘A’ is not supported; requires DWARF-C but target ‘B’ only provides DWARF-D

warning: debug information option ‘A’ is not supported for target ‘B’

-Wunsupported-visibility ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: target does not support ‘protected’ visibility; using ‘default’

-Wunusable-partial-specialization ¶

This diagnostic is an error by default, but the flag -Wno-unusable-partial-specialization can be used to disable the error.

Diagnostic text:

error:

class

variable

template partial specialization contains

a template parameter

template parameters

that cannot be deduced; this partial specialization will never be used

-Wunused ¶

Some of the diagnostics controlled by this flag are enabled by default.

Controls -Wunused-argument, -Wunused-but-set-variable, -Wunused-function, -Wunused-label, -Wunused-lambda-capture, -Wunused-local-typedef, -Wunused-private-field, -Wunused-property-ivar, -Wunused-value, -Wunused-variable.

-Wunused-argument ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wunused-but-set-parameter ¶

Diagnostic text:

warning: parameter A set but not used

-Wunused-but-set-variable ¶

Diagnostic text:

warning: variable A set but not used

-Wunused-command-line-argument ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: argument ‘A’ requires profile-guided optimization information

warning: joined argument expects additional value: ‘A’

warning: A: ‘B’ input unused

when ‘D’ is present

warning: A: ‘B’ input unused in cpp mode

warning: ignoring invalid /arch: argument ‘A’; for

-bit expected one of C

warning: A: previously preprocessed input

unused when ‘C’ is present

warning: argument unused during compilation: ‘A’

warning: ‘-x A’ after last input file has no effect

warning: the flag ‘A’ has been deprecated and will be ignored

warning: ignoring -fdiscard-value-names for LLVM Bitcode

warning: ignoring -fverify-debuginfo-preserve-export=A because -fverify-debuginfo-preserve wasn’t enabled

-Wunused-comparison ¶

This diagnostic is enabled by default.

Diagnostic text:

warning:

equality

inequality

relational

three-way

comparison result unused

-Wunused-const-variable ¶

Diagnostic text:

warning: unused variable A

Diagnostic text:

warning: unused label A

-Wunused-lambda-capture ¶

Diagnostic text:

warning: lambda capture A is not

used

required to be captured for this use

-Wunused-local-typedef ¶

Diagnostic text:

warning: unused

typedef

type alias

-Wunused-local-typedefs ¶

Synonym for -Wunused-local-typedef.

-Wunused-macros ¶

Diagnostic text:

warning: macro is not used

-Wunused-member-function ¶

Also controls -Wunneeded-member-function.

Diagnostic text:

warning: unused member function A

-Wunused-parameter ¶

Diagnostic text:

warning: unused parameter A

-Wunused-private-field ¶

Diagnostic text:

warning: private field A is not used

-Wunused-property-ivar ¶

Diagnostic text:

warning: ivar A which backs the property is not referenced in this property’s accessor

-Wunused-result ¶

This diagnostic is enabled by default.

This diagnostic is enabled by default.

Diagnostic text:

warning: user-defined literal suffixes

Diagnostic text:

warning: incompatible vector types

assigning to A from B

assigning to different types

passing A to parameter of type B

passing to parameter of different type

returning A from a function with result type B

returning from function with different return type

converting A to type B

converting between types

initializing A with an expression of type B

initializing with expression of different type

sending A to parameter of type B

sending to parameter of different type

casting A to type B

casting between types

-Wvector-conversions ¶

Synonym for -Wvector-conversion.

-Wvexing-parse ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: empty parentheses interpreted as a function declaration

warning: parentheses were disambiguated as a function declaration

warning: parentheses were disambiguated as redundant parentheses around declaration of variable named A

-Wvisibility ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: declaration of A will not be visible outside of this function

warning: redefinition of A will not be visible outside of this function

-Wvla ¶

Also controls -Wvla-extension.

Diagnostic text:

warning: variable length array used

-Wvla-extension ¶

Diagnostic text:

warning: variable length arrays are a C99 feature

-Wvoid-pointer-to-enum-cast ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: cast to smaller integer type B from A

-Wvoid-pointer-to-int-cast ¶

This diagnostic is enabled by default.

Also controls -Wvoid-pointer-to-enum-cast.

Diagnostic text:

warning: cast to smaller integer type B from A

-Wvoid-ptr-dereference ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: ISO C does not allow indirection on operand of type A

-Wvolatile-register-var ¶

This diagnostic flag exists for GCC compatibility, and has no effect in Clang.

-Wwasm-exception-spec ¶

This diagnostic is enabled by default.

Diagnostic text:

warning: dynamic exception specifications with types are currently ignored in wasm

-Wweak-template-vtables ¶

Diagnostic text:

warning: this warning is no longer in use and will be removed in the next release

-Wweak-vtables ¶

Diagnostic text:

warning: A has no out-of-line virtual method definitions; its vtable will be emitted in every translation unit

-Wwritable-strings ¶

This diagnostic is enabled by default.

Also controls -Wdeprecated-writable-strings.