Clang command line argument reference¶

Introduction ¶

This page lists the command line arguments currently supported by the GCC-compatible clang and clang++ drivers.

-B<dir>, --prefix <arg>, --prefix=<arg>¶

Add <dir> to search path for binaries and object files used implicitly

-F<arg>¶

Add directory to framework include search path

-ObjC¶

Treat source input files as Objective-C inputs

-ObjC++¶

Treat source input files as Objective-C++ inputs

-Qn, -fno-ident¶

Do not emit metadata containing compiler name and version

-Qunused-arguments¶

Don’t emit warning for unused driver arguments

-Qy, -fident¶

Emit metadata containing compiler name and version

-Wa,<arg>,<arg2>...¶

Pass the comma separated arguments in <arg> to the assembler

-Wlarge-by-value-copy=<arg>¶

-Xarch_<arg1> <arg2>¶

-Xcuda-fatbinary <arg>¶

Pass <arg> to fatbinary invocation

-Xcuda-ptxas <arg>¶

Pass <arg> to the ptxas assembler

-Xopenmp-target <arg>¶

Pass <arg> to the target offloading toolchain.

-Xopenmp-target=<triple> <arg>¶

Pass <arg> to the target offloading toolchain identified by <triple>.

-Z<arg>¶

-a<arg>, --profile-blocks¶

-all_load¶

-allowable_client <arg>¶

--analyze¶

Run the static analyzer

--analyze-auto¶

--analyzer-no-default-checks¶

--analyzer-output<arg>¶

Static analyzer report output format (html|plist|plist-multi-file|plist-html|text).

-ansi, --ansi¶

-arch <arg>¶

-arch_errors_fatal¶

-arch_only <arg>¶

-arcmt-migrate-emit-errors¶

Emit ARC errors even if the migrator can fix them

-arcmt-migrate-report-output <arg>¶

Output path for the plist report

--autocomplete=<arg>¶

-bind_at_load¶

-bundle¶

-bundle_loader <arg>¶

-cfguard¶

Emit tables required for Windows Control Flow Guard.

-client_name<arg>¶

-compatibility_version<arg>¶

--config <arg>¶

Specifies configuration file

--constant-cfstrings¶

-coverage, --coverage¶

--cuda-compile-host-device¶

Compile CUDA code for both host and device (default). Has no effect on non-CUDA compilations.

--cuda-device-only¶

Compile CUDA code for device only

--cuda-gpu-arch=<arg>, --no-cuda-gpu-arch=<arg>¶

CUDA GPU architecture (e.g. sm_35). May be specified more than once.

--cuda-host-only¶

Compile CUDA code for host only. Has no effect on non-CUDA compilations.

--cuda-include-ptx=<arg>, --no-cuda-include-ptx=<arg>¶

Include PTX for the follwing GPU architecture (e.g. sm_35) or ‘all’. May be specified more than once.

--cuda-noopt-device-debug, --no-cuda-noopt-device-debug¶

Enable device-side debug info generation. Disables ptxas optimizations.

-current_version<arg>¶

-dead_strip¶

-dependency-dot <arg>¶

Filename to write DOT-formatted header dependencies to

-dependency-file <arg>¶

Filename (or -) to write dependency output to

-dumpmachine¶

-dumpversion¶

--dyld-prefix=<arg>, --dyld-prefix <arg>¶

-dylib_file <arg>¶

-dylinker¶

-dylinker_install_name<arg>¶

-dynamic¶

-dynamiclib¶

-emit-ast¶

Emit Clang AST files for source inputs

-exported_symbols_list <arg>¶

-faligned-new=<arg>¶

-fcuda-approx-transcendentals, -fno-cuda-approx-transcendentals¶

Use approximate transcendental functions

-fcuda-flush-denormals-to-zero, -fno-cuda-flush-denormals-to-zero¶

Flush denormal floating point values to zero in CUDA device mode.

-fcuda-rdc, -fno-cuda-rdc¶

Generate relocatable device code, also known as separate compilation mode.

-fcuda-short-ptr, -fno-cuda-short-ptr¶

Use 32-bit pointers for accessing const/local/shared address spaces.

-ffixed-r19¶

Reserve register r19 (Hexagon only)

-fheinous-gnu-extensions¶

-flat_namespace¶

-fopenmp-targets=<arg1>,<arg2>...¶

Specify comma-separated list of triples OpenMP offloading targets to be supported

-force_cpusubtype_ALL¶

-force_flat_namespace¶

-force_load <arg>¶

-framework <arg>¶

-frtlib-add-rpath, -fno-rtlib-add-rpath¶

Add -rpath with architecture-specific resource directory to the linker flags

--gcc-toolchain=<arg>, -gcc-toolchain <arg>¶

Use the gcc toolchain at the given directory

-gcodeview¶

Generate CodeView debug information

-headerpad_max_install_names<arg>¶

-help, --help¶

Display available options

--help-hidden¶

Display help for hidden options

--hip-link¶

Link clang-offload-bundler bundles for HIP

-image_base <arg>¶

-index-header-map¶

Make the next included directory (-I or -F) an indexer header map

-init <arg>¶

-install_name <arg>¶

-keep_private_externs¶

-lazy_framework <arg>¶

-lazy_library <arg>¶

-mbig-endian, -EB¶

--migrate¶

Run the migrator

-mios-simulator-version-min=<arg>, -miphonesimulator-version-min=<arg>¶

-mlinker-version=<arg>¶

-mlittle-endian, -EL¶

-mllvm <arg>¶

Additional arguments to forward to LLVM’s option processing

-module-dependency-dir <arg>¶

Directory to dump module dependencies to

-mtvos-simulator-version-min=<arg>, -mappletvsimulator-version-min=<arg>¶

-multi_module¶

-multiply_defined <arg>¶

-multiply_defined_unused <arg>¶

-mwatchos-simulator-version-min=<arg>, -mwatchsimulator-version-min=<arg>¶

--no-cuda-version-check¶

Don’t error out if the detected version of the CUDA install is too low for the requested CUDA gpu architecture.

-no-integrated-cpp, --no-integrated-cpp¶

-no_dead_strip_inits_and_terms¶

-nobuiltininc¶

Disable builtin #include directories

-nocudainc¶

-nocudalib¶

-nodefaultlibs¶

-nofixprebinding¶

-nolibc¶

-nomultidefs¶

-nopie, -no-pie¶

-noprebind¶

-noseglinkedit¶

-nostartfiles¶

-nostdinc, --no-standard-includes¶

-nostdinc++¶

Disable standard #include directories for the C++ standard library

-nostdlib, --no-standard-libraries¶

-nostdlib++¶

-nostdlibinc¶

-o<file>, --output <arg>, --output=<arg>¶

Write output to <file>

-objcmt-atomic-property¶

Make migration to ‘atomic’ properties

-objcmt-migrate-all¶

Enable migration to modern ObjC

-objcmt-migrate-annotation¶

Enable migration to property and method annotations

-objcmt-migrate-designated-init¶

Enable migration to infer NS_DESIGNATED_INITIALIZER for initializer methods

-objcmt-migrate-instancetype¶

Enable migration to infer instancetype for method result type

-objcmt-migrate-literals¶

Enable migration to modern ObjC literals

-objcmt-migrate-ns-macros¶

Enable migration to NS_ENUM/NS_OPTIONS macros

-objcmt-migrate-property¶

Enable migration to modern ObjC property

-objcmt-migrate-property-dot-syntax¶

Enable migration of setter/getter messages to property-dot syntax

-objcmt-migrate-protocol-conformance¶

Enable migration to add protocol conformance on classes

-objcmt-migrate-readonly-property¶

Enable migration to modern ObjC readonly property

-objcmt-migrate-readwrite-property¶

Enable migration to modern ObjC readwrite property

-objcmt-migrate-subscripting¶

Enable migration to modern ObjC subscripting

-objcmt-ns-nonatomic-iosonly¶

Enable migration to use NS_NONATOMIC_IOSONLY macro for setting property’s ‘atomic’ attribute

-objcmt-returns-innerpointer-property¶

Enable migration to annotate property with NS_RETURNS_INNER_POINTER

-objcmt-whitelist-dir-path=<arg>, -objcmt-white-list-dir-path=<arg>¶

Only modify files with a filename contained in the provided directory path

-object¶

-p, --profile¶

-pagezero_size<arg>¶

-pg¶

Enable mcount instrumentation

-pie¶

-pipe, --pipe¶

Use pipes between commands, when possible

-prebind¶

-prebind_all_twolevel_modules¶

-preload¶

--print-diagnostic-categories¶

-print-file-name=<file>, --print-file-name=<file>, --print-file-name <arg>¶

Print the full library path of <file>

-print-ivar-layout¶

Enable Objective-C Ivar layout bitmap print trace

-print-libgcc-file-name, --print-libgcc-file-name¶

Print the library path for the currently used compiler runtime library (“libgcc.a” or “libclang_rt.builtins.*.a”)

-print-multi-directory, --print-multi-directory¶

-print-multi-lib, --print-multi-lib¶

-print-prog-name=<name>, --print-prog-name=<name>, --print-prog-name <arg>¶

Print the full program path of <name>

-print-resource-dir, --print-resource-dir¶

Print the resource directory pathname

-print-search-dirs, --print-search-dirs¶

Print the paths used for finding libraries and programs

-private_bundle¶

-pthread, -no-pthread¶

Support POSIX threads in generated code

-pthreads¶

-rdynamic¶

-read_only_relocs <arg>¶

-relocatable-pch, --relocatable-pch¶

Whether to build a relocatable precompiled header

-remap¶

-rewrite-legacy-objc¶

Rewrite Legacy Objective-C source to C++

-rtlib=<arg>, --rtlib=<arg>, --rtlib <arg>¶

Compiler runtime library to use

-save-stats=<arg>, --save-stats=<arg>, -save-stats (equivalent to -save-stats=cwd), --save-stats (equivalent to -save-stats=cwd)¶

Save llvm statistics.

-save-temps=<arg>, --save-temps=<arg>, -save-temps (equivalent to -save-temps=cwd), --save-temps (equivalent to -save-temps=cwd)¶

Save intermediate compilation results.

-sectalign <arg1> <arg2> <arg3>¶

-sectcreate <arg1> <arg2> <arg3>¶

-sectobjectsymbols <arg1> <arg2>¶

-sectorder <arg1> <arg2> <arg3>¶

-seg1addr<arg>¶

-seg_addr_table <arg>¶

-seg_addr_table_filename <arg>¶

-segaddr <arg1> <arg2>¶

-segcreate <arg1> <arg2> <arg3>¶

-seglinkedit¶

-segprot <arg1> <arg2> <arg3>¶

-segs_read_<arg>¶

-segs_read_only_addr <arg>¶

-segs_read_write_addr <arg>¶

-serialize-diagnostics <arg>, --serialize-diagnostics <arg>¶

Serialize compiler diagnostics to a file

-shared, --shared¶

-shared-libgcc¶

-shared-libsan, -shared-libasan¶

-single_module¶

-specs=<arg>, --specs=<arg>¶

-static, --static¶

-static-libgcc¶

-static-libsan¶

-static-libstdc++¶

-std-default=<arg>¶

-stdlib=<arg>, --stdlib=<arg>, --stdlib <arg>¶

C++ standard library to use

-sub_library<arg>¶

-sub_umbrella<arg>¶

--sysroot=<arg>, --sysroot <arg>¶

--target-help¶

--target=<arg>, -target <arg>¶

Generate code for the given target

-time¶

Time individual commands

-traditional, --traditional¶

-traditional-cpp, --traditional-cpp¶

Enable some traditional CPP emulation

-twolevel_namespace¶

-twolevel_namespace_hints¶

-umbrella <arg>¶

-unexported_symbols_list <arg>¶

-v, --verbose¶

Show commands to run and use verbose output

--verify-debug-info¶

Verify the binary representation of debug output

--version¶

Print version information

-w, --no-warnings¶

Suppress all warnings

-weak-l<arg>¶

-weak_framework <arg>¶

-weak_library <arg>¶

-weak_reference_mismatches <arg>¶

-whatsloaded¶

-whyload¶

-working-directory<arg>, -working-directory=<arg>¶

Resolve file paths relative to the specified directory

-x<language>, --language <arg>, --language=<arg>¶

Treat subsequent input files as having type <language>

-y<arg>¶

Actions ¶

The action to perform on the input.

-E, --preprocess¶

Only run the preprocessor

-S, --assemble¶

Only run preprocess and compilation steps

-c, --compile¶

Only run preprocess, compile, and assemble steps

-emit-llvm¶

Use the LLVM representation for assembler and object files

-fsyntax-only¶

-module-file-info¶

Provide information about a particular module file

--precompile¶

Only precompile the input

-rewrite-objc¶

Rewrite Objective-C source to C++

-verify-pch¶

Load and verify that a pre-compiled header file is not stale

Compilation flags ¶

Flags controlling the behavior of Clang during compilation. These flags have no effect during actions that do not perform compilation.

-Xassembler <arg>¶

Pass <arg> to the assembler

-Xclang <arg>¶

Pass <arg> to the clang compiler

-fclang-abi-compat=<version>¶

Attempt to match the ABI of Clang <version>

-fcomment-block-commands=<arg>,<arg2>...¶

Treat each comma separated argument in <arg> as a documentation comment block command

-fcomplete-member-pointers, -fno-complete-member-pointers¶

Require member pointer base types to be complete if they would be significant under the Microsoft ABI

-fcrash-diagnostics-dir=<arg>¶

-fdeclspec, -fno-declspec¶

Allow __declspec as a keyword

-fdepfile-entry=<arg>¶

-fdiagnostics-fixit-info, -fno-diagnostics-fixit-info¶

-fdiagnostics-format=<arg>¶

-fdiagnostics-parseable-fixits¶

Print fix-its in machine parseable form

-fdiagnostics-print-source-range-info¶

Print source range spans in numeric form

-fdiagnostics-show-category=<arg>¶

-fdiscard-value-names, -fno-discard-value-names¶

Discard value names in LLVM IR

-fexperimental-isel, -fno-experimental-isel¶

Enables the experimental global instruction selector

-fexperimental-new-pass-manager, -fno-experimental-new-pass-manager¶

Enables an experimental new pass manager in LLVM.

-ffine-grained-bitfield-accesses, -fno-fine-grained-bitfield-accesses¶

Use separate accesses for consecutive bitfield runs with legal widths and alignments.

-finline-functions, -fno-inline-functions¶

Inline suitable functions

-finline-hint-functions¶

Inline functions which are (explicitly or implicitly) marked inline

-fno-crash-diagnostics¶

Disable auto-generation of preprocessed source files and a script for reproduction during a clang crash

-fno-sanitize-blacklist¶

Don’t use blacklist file for sanitizers

-fparse-all-comments¶

-fsanitize-address-field-padding=<arg>¶

Level of field padding for AddressSanitizer

-fsanitize-address-globals-dead-stripping¶

Enable linker dead stripping of globals in AddressSanitizer

-fsanitize-address-poison-class-member-array-new-cookie, -fno-sanitize-address-poison-class-member-array-new-cookie¶

Enable poisoning array cookies when using class member operator new[] in AddressSanitizer

-fsanitize-address-use-after-scope, -fno-sanitize-address-use-after-scope¶

Enable use-after-scope detection in AddressSanitizer

-fsanitize-blacklist=<arg>¶

Path to blacklist file for sanitizers

-fsanitize-cfi-cross-dso, -fno-sanitize-cfi-cross-dso¶

Enable control flow integrity (CFI) checks for cross-DSO calls.

-fsanitize-cfi-icall-generalize-pointers¶

Generalize pointers in CFI indirect call type signature checks

-fsanitize-coverage=<arg1>,<arg2>..., -fno-sanitize-coverage=<arg1>,<arg2>...¶

Specify the type of coverage instrumentation for Sanitizers

-fsanitize-link-c++-runtime¶

-fsanitize-memory-track-origins, -fno-sanitize-memory-track-origins¶

Enable origins tracking in MemorySanitizer

-fsanitize-memory-track-origins=<arg>¶

Enable origins tracking in MemorySanitizer

-fsanitize-memory-use-after-dtor, -fno-sanitize-memory-use-after-dtor¶

Enable use-after-destroy detection in MemorySanitizer

-fsanitize-minimal-runtime, -fno-sanitize-minimal-runtime¶

-fsanitize-recover, -fno-sanitize-recover¶

-fsanitize-recover=<arg1>,<arg2>..., -fno-sanitize-recover=<arg1>,<arg2>...¶

Enable recovery for specified sanitizers

-fsanitize-stats, -fno-sanitize-stats¶

Enable sanitizer statistics gathering.

-fsanitize-thread-atomics, -fno-sanitize-thread-atomics¶

Enable atomic operations instrumentation in ThreadSanitizer (default)

-fsanitize-thread-func-entry-exit, -fno-sanitize-thread-func-entry-exit¶

Enable function entry/exit instrumentation in ThreadSanitizer (default)

-fsanitize-thread-memory-access, -fno-sanitize-thread-memory-access¶

Enable memory access instrumentation in ThreadSanitizer (default)

-fsanitize-trap=<arg1>,<arg2>..., -fno-sanitize-trap=<arg1>,<arg2>...¶

Enable trapping for specified sanitizers

-fsanitize-undefined-strip-path-components=<number>¶

Strip (or keep only, if negative) a given number of path components when emitting check metadata.

-fsanitize-undefined-trap-on-error, -fno-sanitize-undefined-trap-on-error¶

-fsanitize=<check>,<arg2>..., -fno-sanitize=<arg1>,<arg2>...¶

Turn on runtime checks for various forms of undefined or suspicious behavior. See user manual for available checks

-moutline, -mno-outline¶

Enable function outlining (AArch64 only)

--param <arg>, --param=<arg>¶

-std=<arg>, --std=<arg>, --std <arg>¶

Language standard to compile for

Preprocessor flags ¶

Flags controlling the behavior of the Clang preprocessor.

-C, --comments¶

Include comments in preprocessed output

-CC, --comments-in-macros¶

Include comments from within macros in preprocessed output

-D<macro>=<value>, --define-macro <arg>, --define-macro=<arg>¶

Define <macro> to <value> (or 1 if <value> omitted)

-H, --trace-includes¶

Show header includes and nesting depth

-P, --no-line-commands¶

Disable linemarker output in -E mode

-U<macro>, --undefine-macro <arg>, --undefine-macro=<arg>¶

Undefine macro <macro>

-Wp,<arg>,<arg2>...¶

Pass the comma separated arguments in <arg> to the preprocessor

-Xpreprocessor <arg>¶

Pass <arg> to the preprocessor

Include path management ¶

Flags controlling how #includes are resolved to files.

-I<dir>, --include-directory <arg>, --include-directory=<arg>¶

Add directory to include search path

-I-, --include-barrier¶

Restrict all prior -I flags to double-quoted inclusion and remove current directory from include path

--cuda-path-ignore-env¶

Ignore environment variables to detect CUDA installation

--cuda-path=<arg>¶

CUDA installation path

-cxx-isystem<directory>¶

Add directory to the C++ SYSTEM include search path

-fbuild-session-file=<file>¶

Use the last modification time of <file> as the build session timestamp

-fbuild-session-timestamp=<time since Epoch in seconds>¶

Time when the current build session started

-fmodule-file=[<name>=]<file>¶

Specify the mapping of module name to precompiled module file, or load a module file if name is omitted.

-fmodules-cache-path=<directory>¶

Specify the module cache path

-fmodules-disable-diagnostic-validation¶

Disable validation of the diagnostic options when loading the module

-fmodules-prune-after=<seconds>¶

Specify the interval (in seconds) after which a module file will be considered unused

-fmodules-prune-interval=<seconds>¶

Specify the interval (in seconds) between attempts to prune the module cache

-fmodules-user-build-path <directory>¶

Specify the module user build path

-fmodules-validate-once-per-build-session¶

Don’t verify input files for the modules if the module has been successfully validated or loaded during this build session

-fmodules-validate-system-headers, -fno-modules-validate-system-headers¶

Validate the system headers that a module depends on when loading the module

-fprebuilt-module-path=<directory>¶

Specify the prebuilt module path

-idirafter<arg>, --include-directory-after <arg>, --include-directory-after=<arg>¶

Add directory to AFTER include search path

-iframework<arg>¶

Add directory to SYSTEM framework search path

-iframeworkwithsysroot<directory>¶

Add directory to SYSTEM framework search path, absolute paths are relative to -isysroot

-imacros<file>, --imacros<file>, --imacros=<arg>¶

Include macros from file before parsing

-include<file>, --include<file>, --include=<arg>¶

Include file before parsing

-include-pch <file>¶

Include precompiled header file

-iprefix<dir>, --include-prefix <arg>, --include-prefix=<arg>¶

Set the -iwithprefix/-iwithprefixbefore prefix

-iquote<directory>¶

Add directory to QUOTE include search path

-isysroot<dir>¶

Set the system root directory (usually /)

-isystem<directory>¶

Add directory to SYSTEM include search path

-isystem-after<directory>¶

Add directory to end of the SYSTEM include search path

-ivfsoverlay<arg>¶

Overlay the virtual filesystem described by file over the real file system

-iwithprefix<dir>, --include-with-prefix <arg>, --include-with-prefix-after <arg>, --include-with-prefix-after=<arg>, --include-with-prefix=<arg>¶

Set directory to SYSTEM include search path with prefix

-iwithprefixbefore<dir>, --include-with-prefix-before <arg>, --include-with-prefix-before=<arg>¶

Set directory to include search path with prefix

-iwithsysroot<directory>¶

Add directory to SYSTEM include search path, absolute paths are relative to -isysroot

--ptxas-path=<arg>¶

Path to ptxas (used for compiling CUDA code)

--system-header-prefix=<prefix>, --no-system-header-prefix=<prefix>, --system-header-prefix <arg>¶

Treat all #include paths starting with <prefix> as including a system header.

Dependency file generation ¶

Flags controlling generation of a dependency file for make-like build systems.

-M, --dependencies¶

Like -MD, but also implies -E and writes to stdout by default

-MD, --write-dependencies¶

Write a depfile containing user and system headers

-MF<file>¶

Write depfile output from -MMD, -MD, -MM, or -M to <file>

-MG, --print-missing-file-dependencies¶

Add missing headers to depfile

-MJ<arg>¶

Write a compilation database entry per input

-MM, --user-dependencies¶

Like -MMD, but also implies -E and writes to stdout by default

-MMD, --write-user-dependencies¶

Write a depfile containing user headers

-MP¶

Create phony target for each dependency (other than main file)

-MQ<arg>¶

Specify name of main file output to quote in depfile

-MT<arg>¶

Specify name of main file output in depfile

-MV¶

Use NMake/Jom format for the depfile

Dumping preprocessor state ¶

Flags allowing the state of the preprocessor to be dumped in various ways.

-d¶

-d<arg>¶

-dA¶

-dD¶

Print macro definitions in -E mode in addition to normal output

-dI¶

Print include directives in -E mode in addition to normal output

-dM¶

Print macro definitions in -E mode instead of normal output

Diagnostic flags ¶

Flags controlling which warnings, errors, and remarks Clang will generate. See the full list of warning and remark flags.

-R<remark>¶

Enable the specified remark

-Rpass-analysis=<arg>¶

Report transformation analysis from optimization passes whose name matches the given POSIX regular expression

-Rpass-missed=<arg>¶

Report missed transformations by optimization passes whose name matches the given POSIX regular expression

-Rpass=<arg>¶

Report transformations performed by optimization passes whose name matches the given POSIX regular expression

-W<warning>, --extra-warnings, --warn-<arg>, --warn-=<arg>¶

Enable the specified warning

-Wdeprecated, -Wno-deprecated¶

Enable warnings for deprecated constructs and define __DEPRECATED

-Wnonportable-cfstrings<arg>, -Wno-nonportable-cfstrings<arg>¶

Target-independent compilation options ¶

-Wframe-larger-than=<arg>¶

-fPIC, -fno-PIC¶

-fPIE, -fno-PIE¶

-faccess-control, -fno-access-control¶

-faddrsig, -fno-addrsig¶

Emit an address-significance table

-falign-functions, -fno-align-functions¶

-falign-functions=<arg>¶

-faligned-allocation, -faligned-new, -fno-aligned-allocation¶

Enable C++17 aligned allocation functions

-fallow-editor-placeholders, -fno-allow-editor-placeholders¶

Treat editor placeholders as valid source code

-fallow-unsupported¶

-faltivec, -fno-altivec¶

-fansi-escape-codes¶

Use ANSI escape codes for diagnostics

-fapple-kext, -findirect-virtual-calls, -fterminated-vtables¶

Use Apple’s kernel extensions ABI

-fapple-pragma-pack, -fno-apple-pragma-pack¶

Enable Apple gcc-compatible #pragma pack handling

-fapplication-extension, -fno-application-extension¶

Restrict code to those available for App Extensions

-fasm, -fno-asm¶

-fasm-blocks, -fno-asm-blocks¶

-fassociative-math, -fno-associative-math¶

-fassume-sane-operator-new, -fno-assume-sane-operator-new¶

-fast¶

-fastcp¶

-fastf¶

-fasynchronous-unwind-tables, -fno-asynchronous-unwind-tables¶

-fautolink, -fno-autolink¶

-fblocks, -fno-blocks¶

Enable the ‘blocks’ language feature

-fbootclasspath=<arg>, --bootclasspath <arg>, --bootclasspath=<arg>¶

-fborland-extensions, -fno-borland-extensions¶

Accept non-standard constructs supported by the Borland compiler

-fbracket-depth=<arg>¶

-fbuiltin, -fno-builtin¶

-fbuiltin-module-map¶

Load the clang builtins module map file.

-fcaret-diagnostics, -fno-caret-diagnostics¶

-fcf-protection=<arg>, -fcf-protection (equivalent to -fcf-protection=full)¶

Instrument control-flow architecture protection. Options: return, branch, full, none.

-fchar8_t, -fno-char8_t¶

Enable C++ builtin type char8_t

-fclasspath=<arg>, --CLASSPATH <arg>, --CLASSPATH=<arg>, --classpath <arg>, --classpath=<arg>¶

-fcolor-diagnostics, -fno-color-diagnostics¶

Use colors in diagnostics

-fcommon, -fno-common¶

-fcompile-resource=<arg>, --resource <arg>, --resource=<arg>¶

-fconstant-cfstrings, -fno-constant-cfstrings¶

-fconstant-string-class=<arg>¶

-fconstexpr-backtrace-limit=<arg>¶

-fconstexpr-depth=<arg>¶

-fconstexpr-steps=<arg>¶

-fcoroutines-ts, -fno-coroutines-ts¶

Enable support for the C++ Coroutines TS

-fcoverage-mapping, -fno-coverage-mapping¶

Generate coverage mapping to enable code coverage analysis

-fcreate-profile¶

-fcxx-exceptions, -fno-cxx-exceptions¶

Enable C++ exceptions

-fcxx-modules, -fno-cxx-modules¶

-fdata-sections, -fno-data-sections¶

Place each data in its own section (ELF Only)

-fdebug-info-for-profiling, -fno-debug-info-for-profiling¶

Emit extra debug info to make sample profile more accurate.

-fdebug-macro, -fno-debug-macro¶

Emit macro debug information

-fdebug-pass-arguments¶

-fdebug-pass-structure¶

-fdebug-prefix-map=<arg>¶

remap file source paths in debug info

-fdebug-types-section, -fno-debug-types-section¶

Place debug types in their own section (ELF Only)

-fdelayed-template-parsing, -fno-delayed-template-parsing¶

Parse templated function definitions at the end of the translation unit

-fdelete-null-pointer-checks, -fno-delete-null-pointer-checks¶

Treat usage of null pointers as undefined behavior.

-fdenormal-fp-math=<arg>¶

-fdiagnostics-absolute-paths¶

Print absolute paths in diagnostics

-fdiagnostics-color, -fno-diagnostics-color¶

-fdiagnostics-color=<arg>¶

-fdiagnostics-hotness-threshold=<number>¶

Prevent optimization remarks from being output if they do not have at least this profile count

-fdiagnostics-show-hotness, -fno-diagnostics-show-hotness¶

Enable profile hotness information in diagnostic line

-fdiagnostics-show-note-include-stack, -fno-diagnostics-show-note-include-stack¶

Display include stacks for diagnostic notes

-fdiagnostics-show-option, -fno-diagnostics-show-option¶

Print option name with mappable diagnostics

-fdiagnostics-show-template-tree¶

Print a template comparison tree for differing templates

-fdigraphs, -fno-digraphs¶

Enable alternative token representations ‘<:’, ‘:>’, ‘<%’, ‘%>’, ‘%:’, ‘%:%:’ (default)

-fdollars-in-identifiers, -fno-dollars-in-identifiers¶

Allow ‘$’ in identifiers

-fdouble-square-bracket-attributes, -fno-double-square-bracket-attributes¶

Enable ‘[[]]’ attributes in all C and C++ language modes

-fdwarf-directory-asm, -fno-dwarf-directory-asm¶

-fdwarf-exceptions¶

Use DWARF style exceptions

-felide-constructors, -fno-elide-constructors¶

-feliminate-unused-debug-symbols, -fno-eliminate-unused-debug-symbols¶

-fembed-bitcode=<option>, -fembed-bitcode (equivalent to -fembed-bitcode=all), -fembed-bitcode-marker (equivalent to -fembed-bitcode=marker)¶

Embed LLVM bitcode (option: off, all, bitcode, marker)

-femit-all-decls¶

Emit all declarations, even if unused

-femulated-tls, -fno-emulated-tls¶

Use emutls functions to access thread_local variables

-fencoding=<arg>, --encoding <arg>, --encoding=<arg>¶

-ferror-limit=<arg>¶

-fescaping-block-tail-calls, -fno-escaping-block-tail-calls¶

-fexceptions, -fno-exceptions¶

Enable support for exception handling

-fexec-charset=<arg>¶

-fextdirs=<arg>, --extdirs <arg>, --extdirs=<arg>¶

-ffast-math, -fno-fast-math¶

Allow aggressive, lossy floating-point optimizations

-ffinite-math-only, -fno-finite-math-only¶

-ffixed-point, -fno-fixed-point¶

Enable fixed point types

-ffor-scope, -fno-for-scope¶

-fforce-emit-vtables, -fno-force-emit-vtables¶

Emits more virtual tables to improve devirtualization

-fforce-enable-int128, -fno-force-enable-int128¶

Enable support for int128_t type

-ffp-contract=<arg>¶

Form fused FP ops (e.g. FMAs): fast (everywhere) | on (according to FP_CONTRACT pragma, default) | off (never fuse)

-ffreestanding¶

Assert that the compilation takes place in a freestanding environment

-ffunction-sections, -fno-function-sections¶

Place each function in its own section (ELF Only)

-fgnu-inline-asm, -fno-gnu-inline-asm¶

-fgnu-keywords, -fno-gnu-keywords¶

Allow GNU-extension keywords regardless of language standard

-fgnu-runtime¶

Generate output compatible with the standard GNU Objective-C runtime

-fgnu89-inline, -fno-gnu89-inline¶

Use the gnu89 inline semantics

-fhonor-infinities, -fhonor-infinites, -fno-honor-infinities¶

-fhonor-nans, -fno-honor-nans¶

-fhosted¶

-fimplicit-module-maps, -fmodule-maps, -fno-implicit-module-maps¶

Implicitly search the file system for module map files.

-fimplicit-modules, -fno-implicit-modules¶

-finput-charset=<arg>¶

-finstrument-function-entry-bare¶

Instrument function entry only, after inlining, without arguments to the instrumentation call

-finstrument-functions¶

Generate calls to instrument function entry and exit

-finstrument-functions-after-inlining¶

Like -finstrument-functions, but insert the calls after inlining

-fintegrated-as, -fno-integrated-as, -integrated-as¶

Enable the integrated assembler

-fjump-tables, -fno-jump-tables¶

-flax-vector-conversions, -fno-lax-vector-conversions¶

-flimited-precision=<arg>¶

-flto, -fno-lto¶

Enable LTO in ‘full’ mode

-flto-jobs=<arg>¶

Controls the backend parallelism of -flto=thin (default of 0 means the number of threads will be derived from the number of CPUs detected)

-flto=<arg>¶

Set LTO mode to either ‘full’ or ‘thin’

-fmacro-backtrace-limit=<arg>¶

-fmath-errno, -fno-math-errno¶

Require math functions to indicate errors by setting errno

-fmax-type-align=<arg>¶

Specify the maximum alignment to enforce on pointers lacking an explicit alignment

-fmerge-all-constants, -fno-merge-all-constants¶

Allow merging of constants

-fmessage-length=<arg>¶

-fmodule-file-deps, -fno-module-file-deps¶

-fmodule-map-file=<file>¶

Load this module map file

-fmodule-name=<name>, -fmodule-implementation-of <arg>, -fmodule-name <arg>¶

Specify the name of the module to build

-fmodules, -fno-modules¶

Enable the ‘modules’ language feature

-fmodules-decluse, -fno-modules-decluse¶

Require declaration of modules used within a module

-fmodules-ignore-macro=<arg>¶

Ignore the definition of the given macro when building and loading modules

-fmodules-search-all, -fno-modules-search-all¶

Search even non-imported modules to resolve references

-fmodules-strict-decluse¶

Like -fmodules-decluse but requires all headers to be in modules

-fmodules-ts¶

Enable support for the C++ Modules TS

-fms-compatibility, -fno-ms-compatibility¶

Enable full Microsoft Visual C++ compatibility

-fms-compatibility-version=<arg>¶

Dot-separated value representing the Microsoft compiler version number to report in _MSC_VER (0 = don’t define it (default))

-fms-extensions, -fno-ms-extensions¶

Accept some non-standard constructs supported by the Microsoft compiler

-fms-memptr-rep=<arg>¶

-fms-volatile<arg>¶

-fmsc-version=<arg>¶

Microsoft compiler version number to report in _MSC_VER (0 = don’t define it (default))

-fmudflap¶

-fmudflapth¶

-fnested-functions¶

-fnew-alignment=<align>, -fnew-alignment <arg>¶

Specifies the largest alignment guaranteed by ‘::operator new(size_t)’

-fnext-runtime¶

-fno-builtin-<arg>¶

Disable implicit builtin knowledge of a specific function

-fno-elide-type¶

Do not elide types when printing diagnostics

-fno-max-type-align¶

-fno-operator-names¶

Do not treat C++ operator name keywords as synonyms for operators

-fno-rtti-data¶

Control emission of RTTI data

-fno-strict-modules-decluse¶

-fno-working-directory¶

-fnoxray-link-deps¶

-fobjc-abi-version=<arg>¶

-fobjc-arc, -fno-objc-arc¶

Synthesize retain and release calls for Objective-C pointers

-fobjc-arc-exceptions, -fno-objc-arc-exceptions¶

Use EH-safe code when synthesizing retains and releases in -fobjc-arc

-fobjc-exceptions, -fno-objc-exceptions¶

Enable Objective-C exceptions

-fobjc-infer-related-result-type, -fno-objc-infer-related-result-type¶

-fobjc-legacy-dispatch, -fno-objc-legacy-dispatch¶

-fobjc-link-runtime¶

-fobjc-nonfragile-abi, -fno-objc-nonfragile-abi¶

-fobjc-nonfragile-abi-version=<arg>¶

-fobjc-runtime=<arg>¶

Specify the target Objective-C runtime kind and version

-fobjc-sender-dependent-dispatch¶

-fobjc-weak, -fno-objc-weak¶

Enable ARC-style weak references in Objective-C

-fomit-frame-pointer, -fno-omit-frame-pointer¶

-fopenmp, -fno-openmp¶

Parse OpenMP pragmas and generate parallel code.

-fopenmp-simd, -fno-openmp-simd¶

Emit OpenMP code only for SIMD-based constructs.

-fopenmp-version=<arg>¶

-fopenmp=<arg>¶

-foperator-arrow-depth=<arg>¶

-foptimization-record-file=<arg>¶

Specify the file name of any generated YAML optimization record

-foptimize-sibling-calls, -fno-optimize-sibling-calls¶

-foutput-class-dir=<arg>, --output-class-directory <arg>, --output-class-directory=<arg>¶

-fpack-struct, -fno-pack-struct¶

-fpack-struct=<arg>¶

Specify the default maximum struct packing alignment

-fpascal-strings, -fno-pascal-strings, -mpascal-strings¶

Recognize and construct Pascal-style string literals

-fpcc-struct-return¶

Override the default ABI to return all structs on the stack

-fpch-preprocess¶

-fpic, -fno-pic¶

-fpie, -fno-pie¶

-fplt, -fno-plt¶

Use the PLT to make function calls

-fplugin=<dsopath>¶

Load the named plugin (dynamic shared object)

-fpreserve-as-comments, -fno-preserve-as-comments¶

-fprofile-arcs, -fno-profile-arcs¶

-fprofile-dir=<arg>¶

-fprofile-generate, -fno-profile-generate¶

Generate instrumented code to collect execution counts into default.profraw (overridden by LLVM_PROFILE_FILE env var)

-fprofile-generate=<directory>¶

Generate instrumented code to collect execution counts into <directory>/default.profraw (overridden by LLVM_PROFILE_FILE env var)

-fprofile-instr-generate, -fno-profile-instr-generate¶

Generate instrumented code to collect execution counts into default.profraw file (overridden by ‘=’ form of option or LLVM_PROFILE_FILE env var)

-fprofile-instr-generate=<file>¶

Generate instrumented code to collect execution counts into <file> (overridden by LLVM_PROFILE_FILE env var)

-fprofile-instr-use, -fno-profile-instr-use, -fprofile-use¶

-fprofile-instr-use=<arg>¶

Use instrumentation data for profile-guided optimization

-fprofile-sample-accurate, -fauto-profile-accurate, -fno-profile-sample-accurate¶

Specifies that the sample profile is accurate. If the sample: profile is accurate, callsites without profile samples are marked as cold. Otherwise, treat callsites without profile samples as if we have no profile

-fprofile-sample-use, -fauto-profile, -fno-profile-sample-use¶

-fprofile-sample-use=<arg>, -fauto-profile=<arg>¶

Enable sample-based profile guided optimizations

-fprofile-use=<pathname>¶

Use instrumentation data for profile-guided optimization. If pathname is a directory, it reads from <pathname>/default.profdata. Otherwise, it reads from file <pathname>.

-freciprocal-math, -fno-reciprocal-math¶

Allow division operations to be reassociated

-freg-struct-return¶

Override the default ABI to return small structs in registers

-fregister-global-dtors-with-atexit, -fno-register-global-dtors-with-atexit¶

Use atexit or __cxa_atexit to register global destructors

-frelaxed-template-template-args, -fno-relaxed-template-template-args¶

Enable C++17 relaxed template template argument matching

-freroll-loops, -fno-reroll-loops¶

Turn on loop reroller

-fretain-comments-from-system-headers¶

-frewrite-imports, -fno-rewrite-imports¶

-frewrite-includes, -fno-rewrite-includes¶

-frewrite-map-file <arg>¶

-frewrite-map-file=<arg>¶

-fropi, -fno-ropi¶

-frtti, -fno-rtti¶

-frwpi, -fno-rwpi¶

-fsave-optimization-record, -fno-save-optimization-record¶

Generate a YAML optimization record file

-fseh-exceptions¶

Use SEH style exceptions

-fshort-enums, -fno-short-enums¶

Allocate to an enum type only as many bytes as it needs for the declared range of possible values

-fshort-wchar, -fno-short-wchar¶

Force wchar_t to be a short unsigned int

-fshow-column, -fno-show-column¶

-fshow-overloads=<arg>¶

Which overload candidates to show when overload resolution fails: best|all; defaults to all

-fshow-source-location, -fno-show-source-location¶

-fsignaling-math, -fno-signaling-math¶

-fsigned-bitfields¶

-fsigned-char, -fno-signed-char, --signed-char¶

-fsigned-zeros, -fno-signed-zeros¶

-fsized-deallocation, -fno-sized-deallocation¶

Enable C++14 sized global deallocation functions

-fsjlj-exceptions¶

Use SjLj style exceptions

-fslp-vectorize, -fno-slp-vectorize, -ftree-slp-vectorize¶

Enable the superword-level parallelism vectorization passes

-fspell-checking, -fno-spell-checking¶

-fspell-checking-limit=<arg>¶

-fsplit-dwarf-inlining, -fno-split-dwarf-inlining¶

Provide minimal debug info in the object/executable to facilitate online symbolication/stack traces in the absence of .dwo/.dwp files when using Split DWARF

-fsplit-stack¶

-fstack-protector, -fno-stack-protector¶

Enable stack protectors for functions potentially vulnerable to stack smashing

-fstack-protector-all¶

Force the usage of stack protectors for all functions

-fstack-protector-strong¶

Use a strong heuristic to apply stack protectors to functions

-fstack-size-section, -fno-stack-size-section¶

Emit section containing metadata on function stack sizes

-fstandalone-debug, -fno-limit-debug-info, -fno-standalone-debug¶

Emit full debug info for all types used by the program

-fstrict-aliasing, -fno-strict-aliasing¶

-fstrict-enums, -fno-strict-enums¶

Enable optimizations based on the strict definition of an enum’s value range

-fstrict-float-cast-overflow, -fno-strict-float-cast-overflow¶

Assume that overflowing float-to-int casts are undefined (default)

-fstrict-overflow, -fno-strict-overflow¶

-fstrict-return, -fno-strict-return¶

Always treat control flow paths that fall off the end of a non-void function as unreachable

-fstrict-vtable-pointers, -fno-strict-vtable-pointers¶

Enable optimizations based on the strict rules for overwriting polymorphic C++ objects

-fstruct-path-tbaa, -fno-struct-path-tbaa¶

-ftabstop=<arg>¶

-ftemplate-backtrace-limit=<arg>¶

-ftemplate-depth-<arg>¶

-ftemplate-depth=<arg>¶

-ftest-coverage¶

-fthinlto-index=<arg>¶

Perform ThinLTO importing using provided function summary index

-fthreadsafe-statics, -fno-threadsafe-statics¶

-ftime-report¶

-ftls-model=<arg>¶

-ftrap-function=<arg>¶

Issue call to specified function rather than a trap instruction

-ftrapping-math, -fno-trapping-math¶

-ftrapv¶

Trap on integer overflow

-ftrapv-handler <arg>¶

-ftrapv-handler=<function name>¶

Specify the function to be called on overflow

-ftrigraphs, -fno-trigraphs, -trigraphs, --trigraphs¶

Process trigraph sequences

-funique-section-names, -fno-unique-section-names¶

Use unique names for text and data sections (ELF Only)

-funit-at-a-time, -fno-unit-at-a-time¶

-funroll-loops, -fno-unroll-loops¶

Turn on loop unroller

-funsafe-math-optimizations, -fno-unsafe-math-optimizations¶

-funsigned-bitfields¶

-funsigned-char, -fno-unsigned-char, --unsigned-char¶

-funwind-tables, -fno-unwind-tables¶

-fuse-cxa-atexit, -fno-use-cxa-atexit¶

-fuse-init-array, -fno-use-init-array¶

Use .init_array instead of .ctors

-fuse-ld=<arg>¶

-fuse-line-directives, -fno-use-line-directives¶

-fveclib=<arg>¶

Use the given vector functions library

-fvectorize, -fno-vectorize, -ftree-vectorize¶

Enable the loop vectorization passes

-fverbose-asm, -fno-verbose-asm¶

-fvisibility-inlines-hidden¶

Give inline C++ member functions hidden visibility by default

-fvisibility-ms-compat¶

Give global types ‘default’ visibility and global functions and variables ‘hidden’ visibility by default

-fvisibility=<arg>¶

Set the default symbol visibility for all global declarations

-fwhole-program-vtables, -fno-whole-program-vtables¶

Enables whole-program vtable optimization. Requires -flto

-fwrapv, -fno-wrapv¶

Treat signed integer overflow as two’s complement

-fwritable-strings¶

Store string literals as writable data

-fxray-always-emit-customevents, -fno-xray-always-emit-customevents¶

Determine whether to always emit __xray_customevent(…) calls even if the function it appears in is not always instrumented.

-fxray-always-emit-typedevents, -fno-xray-always-emit-typedevents¶

Determine whether to always emit __xray_typedevent(…) calls even if the function it appears in is not always instrumented.

-fxray-always-instrument=<arg>¶

DEPRECATED: Filename defining the whitelist for imbuing the ‘always instrument’ XRay attribute.

-fxray-attr-list=<arg>¶

Filename defining the list of functions/types for imbuing XRay attributes.

-fxray-instruction-threshold<arg>¶

-fxray-instruction-threshold=<arg>¶

Sets the minimum function size to instrument with XRay

-fxray-instrument, -fno-xray-instrument¶

Generate XRay instrumentation sleds on function entry and exit

-fxray-instrumentation-bundle=<arg>¶

Select which XRay instrumentation points to emit. Options: all, none, function, custom. Default is ‘all’.

-fxray-link-deps¶

Tells clang to add the link dependencies for XRay.

-fxray-modes=<arg>¶

List of modes to link in by default into XRay instrumented binaries.

-fxray-never-instrument=<arg>¶

DEPRECATED: Filename defining the whitelist for imbuing the ‘never instrument’ XRay attribute.

-fzero-initialized-in-bss, -fno-zero-initialized-in-bss¶

-fzvector, -fno-zvector, -mzvector¶

Enable System z vector language extension

-pedantic, --pedantic, -no-pedantic, --no-pedantic¶

-pedantic-errors, --pedantic-errors¶

OpenCL flags ¶

-cl-denorms-are-zero¶

OpenCL only. Allow denormals to be flushed to zero.

-cl-fast-relaxed-math¶

OpenCL only. Sets -cl-finite-math-only and -cl-unsafe-math-optimizations, and defines __FAST_RELAXED_MATH__.

-cl-finite-math-only¶

OpenCL only. Allow floating-point optimizations that assume arguments and results are not NaNs or +-Inf.

-cl-fp32-correctly-rounded-divide-sqrt¶

OpenCL only. Specify that single precision floating-point divide and sqrt used in the program source are correctly rounded.

-cl-kernel-arg-info¶

OpenCL only. Generate kernel argument metadata.

-cl-mad-enable¶

OpenCL only. Allow use of less precise MAD computations in the generated binary.

-cl-no-signed-zeros¶

OpenCL only. Allow use of less precise no signed zeros computations in the generated binary.

-cl-opt-disable¶

OpenCL only. This option disables all optimizations. By default optimizations are enabled.

-cl-single-precision-constant¶

OpenCL only. Treat double precision floating-point constant as single precision constant.

-cl-std=<arg>¶

OpenCL language standard to compile for.

-cl-strict-aliasing¶

OpenCL only. This option is added for compatibility with OpenCL 1.0.

-cl-uniform-work-group-size¶

OpenCL only. Defines that the global work-size be a multiple of the work-group size specified to clEnqueueNDRangeKernel

-cl-unsafe-math-optimizations¶

OpenCL only. Allow unsafe floating-point optimizations. Also implies -cl-no-signed-zeros and -cl-mad-enable.

Target-dependent compilation options ¶

-G<size>, -G=<arg>, -msmall-data-threshold=<arg>¶

Put objects of at most <size> bytes into small data section (MIPS / Hexagon)

-m16¶

-m32¶

-m64¶

-mabi=<arg>¶

-malign-double¶

Align doubles to two words in structs (x86 only)

-march=<arg>¶

-masm=<arg>¶

-mbackchain, -mno-backchain¶

Link stack frames through backchain on System Z

-mcmodel=<arg>¶

-mconsole<arg>¶

-mcpu=<arg>, -mv4 (equivalent to -mcpu=hexagonv4), -mv5 (equivalent to -mcpu=hexagonv5), -mv55 (equivalent to -mcpu=hexagonv55), -mv60 (equivalent to -mcpu=hexagonv60), -mv62 (equivalent to -mcpu=hexagonv62), -mv65 (equivalent to -mcpu=hexagonv65)¶

-mcrc, -mno-crc¶

Allow use of CRC instructions (ARM/Mips only)

-mdefault-build-attributes<arg>, -mno-default-build-attributes<arg>¶

-mdll<arg>¶

-mdynamic-no-pic<arg>¶

-meabi <arg>¶

Set EABI type, e.g. 4, 5 or gnu (default depends on triple)

-mfentry¶

Insert calls to fentry at function entry (x86 only)

-mfloat-abi=<arg>¶

-mfpmath=<arg>¶

-mfpu=<arg>¶

-mglobal-merge, -mno-global-merge¶

Enable merging of globals

-mhard-float¶

-mhwdiv=<arg>, --mhwdiv <arg>, --mhwdiv=<arg>¶

-miamcu, -mno-iamcu¶

Use Intel MCU ABI

-mimplicit-float, -mno-implicit-float¶

-mimplicit-it=<arg>¶

-mincremental-linker-compatible, -mno-incremental-linker-compatible¶

(integrated-as) Emit an object file which can be used with an incremental linker

-miphoneos-version-min=<arg>, -mios-version-min=<arg>¶

-mkernel¶

-mlong-calls, -mno-long-calls¶

Generate branches with extended addressability, usually via indirect jumps.

-mmacosx-version-min=<arg>, -mmacos-version-min=<arg>¶

Set Mac OS X deployment target

-mmcu=<arg>¶

-mms-bitfields, -mno-ms-bitfields¶

Set the default structure layout to be compatible with the Microsoft compiler standard

-momit-leaf-frame-pointer, -mno-omit-leaf-frame-pointer¶

Omit frame pointer setup for leaf functions

-moslib=<arg>¶

-mpie-copy-relocations, -mno-pie-copy-relocations¶

Use copy relocations support for PIE builds

-mprefer-vector-width=<arg>¶

Specifies preferred vector width for auto-vectorization. Defaults to ‘none’ which allows target specific decisions.

-mqdsp6-compat¶

Enable hexagon-qdsp6 backward compatibility

-mrecip¶

-mrecip=<arg1>,<arg2>...¶

-mred-zone, -mno-red-zone¶

-mregparm=<arg>¶

-mrelax-all, -mno-relax-all¶

(integrated-as) Relax all machine instructions

-mrtd, -mno-rtd¶

Make StdCall calling convention the default

-msoft-float, -mno-soft-float¶

Use software floating point

-mstack-alignment=<arg>¶

Set the stack alignment

-mstack-arg-probe, -mno-stack-arg-probe¶

Enable stack probes

-mstack-probe-size=<arg>¶

Set the stack probe size

-mstackrealign, -mno-stackrealign¶

Force realign the stack at entry to every function

-mthread-model <arg>¶

The thread model to use, e.g. posix, single (posix by default)

-mthreads<arg>¶

-mthumb, -mno-thumb¶

-mtune=<arg>¶

-mtvos-version-min=<arg>, -mappletvos-version-min=<arg>¶

-municode<arg>¶

-mvx, -mno-vx¶

-mwarn-nonportable-cfstrings, -mno-warn-nonportable-cfstrings¶

-mwatchos-version-min=<arg>¶

-mwindows<arg>¶

-mx32¶

AARCH64 ¶

-ffixed-x18¶

Reserve the x18 register (AArch64 only)

-ffixed-x20¶

Reserve the x20 register (AArch64 only)

-mfix-cortex-a53-835769, -mno-fix-cortex-a53-835769¶

Workaround Cortex-A53 erratum 835769 (AArch64 only)

-mgeneral-regs-only¶

Generate code which only uses the general purpose registers (AArch64 only)

AMDGPU ¶

-mxnack, -mno-xnack¶

Enable XNACK (AMDGPU only)

ARM ¶

-ffixed-r9¶

Reserve the r9 register (ARM only)

-mexecute-only, -mno-execute-only, -mpure-code¶

Disallow generation of data access to code sections (ARM only)

-mno-movt¶

Disallow use of movt/movw pairs (ARM only)

-mno-neg-immediates¶

Disallow converting instructions with negative immediates to their negation or inversion.

-mnocrc¶

Disallow use of CRC instructions (ARM only)

-mrestrict-it, -mno-restrict-it¶

Disallow generation of deprecated IT blocks for ARMv8. It is on by default for ARMv8 Thumb mode.

-mtp=<arg>¶

Read thread pointer from coprocessor register (ARM only)

-munaligned-access, -mno-unaligned-access¶

Allow memory accesses to be unaligned (AArch32/AArch64 only)

Hexagon ¶

-mieee-rnd-near¶

-mmemops, -mno-memops¶

Enable generation of memop instructions

-mnvj, -mno-nvj¶

Enable generation of new-value jumps

-mnvs, -mno-nvs¶

Enable generation of new-value stores

-mpackets, -mno-packets¶

Enable generation of instruction packets

Hexagon ¶

-mhvx, -mno-hvx¶

Enable Hexagon Vector eXtensions

-mhvx-length=<arg>¶

Set Hexagon Vector Length

-mhvx=<arg>¶

Enable Hexagon Vector eXtensions

MIPS ¶

-mabicalls, -mno-abicalls¶

Enable SVR4-style position-independent code (Mips only)

-mabs=<arg>¶

-mcheck-zero-division, -mno-check-zero-division¶

-mcompact-branches=<arg>¶

-mdouble-float¶

-mdsp, -mno-dsp¶

-mdspr2, -mno-dspr2¶

-membedded-data, -mno-embedded-data¶

Place constants in the .rodata section instead of the .sdata section even if they meet the -G <size> threshold (MIPS)

-mextern-sdata, -mno-extern-sdata¶

Assume that externally defined data is in the small data if it meets the -G <size> threshold (MIPS)

-mfp32¶

Use 32-bit floating point registers (MIPS only)

-mfp64¶

Use 64-bit floating point registers (MIPS only)

-mginv, -mno-ginv¶

-mgpopt, -mno-gpopt¶

Use GP relative accesses for symbols known to be in a small data section (MIPS)

-mindirect-jump=<arg>¶

Change indirect jump instructions to inhibit speculation

-mips16¶

-mldc1-sdc1, -mno-ldc1-sdc1¶

-mlocal-sdata, -mno-local-sdata¶

Extend the -G behaviour to object local data (MIPS)

-mmadd4, -mno-madd4¶

Enable the generation of 4-operand madd.s, madd.d and related instructions.

-mmicromips, -mno-micromips¶

-mmsa, -mno-msa¶

Enable MSA ASE (MIPS only)

-mmt, -mno-mt¶

Enable MT ASE (MIPS only)

-mnan=<arg>¶

-mno-mips16¶

-msingle-float¶

-mvirt, -mno-virt¶

-mxgot, -mno-xgot¶

PowerPC ¶

-maltivec, -mno-altivec¶

-mcmpb, -mno-cmpb¶

-mcrbits, -mno-crbits¶

-mcrypto, -mno-crypto¶

-mdirect-move, -mno-direct-move¶

-mfloat128, -mno-float128¶

-mfprnd, -mno-fprnd¶

-mhtm, -mno-htm¶

-minvariant-function-descriptors, -mno-invariant-function-descriptors¶

-misel, -mno-isel¶

-mlongcall, -mno-longcall¶

-mmfocrf, -mmfcrf, -mno-mfocrf¶

-mpopcntd, -mno-popcntd¶

-mpower8-vector, -mno-power8-vector¶

-mpower9-vector, -mno-power9-vector¶

-mqpx, -mno-qpx¶

-msecure-plt¶

-mvsx, -mno-vsx¶

WebAssembly ¶

-mexception-handling, -mno-exception-handling¶

-mnontrapping-fptoint, -mno-nontrapping-fptoint¶

-msign-ext, -mno-sign-ext¶

-msimd128, -mno-simd128¶

X86 ¶

-m3dnow, -mno-3dnow¶

-m3dnowa, -mno-3dnowa¶

-madx, -mno-adx¶

-maes, -mno-aes¶

-mavx, -mno-avx¶

-mavx2, -mno-avx2¶

-mavx512bitalg, -mno-avx512bitalg¶

-mavx512bw, -mno-avx512bw¶

-mavx512cd, -mno-avx512cd¶

-mavx512dq, -mno-avx512dq¶

-mavx512er, -mno-avx512er¶

-mavx512f, -mno-avx512f¶

-mavx512ifma, -mno-avx512ifma¶

-mavx512pf, -mno-avx512pf¶

-mavx512vbmi, -mno-avx512vbmi¶

-mavx512vbmi2, -mno-avx512vbmi2¶

-mavx512vl, -mno-avx512vl¶

-mavx512vnni, -mno-avx512vnni¶

-mavx512vpopcntdq, -mno-avx512vpopcntdq¶

-mbmi, -mno-bmi¶

-mbmi2, -mno-bmi2¶

-mcldemote, -mno-cldemote¶

-mclflushopt, -mno-clflushopt¶

-mclwb, -mno-clwb¶

-mclzero, -mno-clzero¶

-mcx16, -mno-cx16¶

-mf16c, -mno-f16c¶

-mfma, -mno-fma¶

-mfma4, -mno-fma4¶

-mfsgsbase, -mno-fsgsbase¶

-mfxsr, -mno-fxsr¶

-mgfni, -mno-gfni¶

-minvpcid, -mno-invpcid¶

-mlwp, -mno-lwp¶

-mlzcnt, -mno-lzcnt¶

-mmmx, -mno-mmx¶

-mmovbe, -mno-movbe¶

-mmovdir64b, -mno-movdir64b¶

-mmovdiri, -mno-movdiri¶

-mmpx, -mno-mpx¶

-mmwaitx, -mno-mwaitx¶

-mpclmul, -mno-pclmul¶

-mpconfig, -mno-pconfig¶

-mpku, -mno-pku¶

-mpopcnt, -mno-popcnt¶

-mprefetchwt1, -mno-prefetchwt1¶

-mprfchw, -mno-prfchw¶

-mptwrite, -mno-ptwrite¶

-mrdpid, -mno-rdpid¶

-mrdrnd, -mno-rdrnd¶

-mrdseed, -mno-rdseed¶

-mretpoline, -mno-retpoline¶

-mretpoline-external-thunk, -mno-retpoline-external-thunk¶

-mrtm, -mno-rtm¶

-msahf, -mno-sahf¶

-msgx, -mno-sgx¶

-msha, -mno-sha¶

-mshstk, -mno-shstk¶

-msse, -mno-sse¶

-msse2, -mno-sse2¶

-msse3, -mno-sse3¶

-msse4.1, -mno-sse4.1¶

-msse4.2, -mno-sse4.2, -msse4¶

-msse4a, -mno-sse4a¶

-mssse3, -mno-ssse3¶

-mtbm, -mno-tbm¶

-mvaes, -mno-vaes¶

-mvpclmulqdq, -mno-vpclmulqdq¶

-mwaitpkg, -mno-waitpkg¶

-mwbnoinvd, -mno-wbnoinvd¶

-mx87, -m80387, -mno-x87¶

-mxop, -mno-xop¶

-mxsave, -mno-xsave¶

-mxsavec, -mno-xsavec¶

-mxsaveopt, -mno-xsaveopt¶

-mxsaves, -mno-xsaves¶

RISCV ¶

-mrelax, -mno-relax¶

Enable linker relaxation

Optimization level ¶

Flags controlling how much optimization should be performed.

-O<arg>, -O (equivalent to -O2), --optimize, --optimize=<arg>¶

-Ofast<arg>¶

Debug information generation ¶

Flags controlling how much and what kind of debug information should be generated.

Kind and level of debug information ¶

-g, --debug, --debug=<arg>¶

Generate source-level debug information

-gdwarf-2¶

Generate source-level debug information with dwarf version 2

-gdwarf-3¶

Generate source-level debug information with dwarf version 3

-gdwarf-4, -gdwarf¶

Generate source-level debug information with dwarf version 4

-gdwarf-5¶

Generate source-level debug information with dwarf version 5

-gfull¶

-gused¶

Debug level ¶

-g0¶

-g2¶

-g3¶

-ggdb0¶

-ggdb1¶

-ggdb2¶

-ggdb3¶

-gline-tables-only, -g1, -gmlt¶

Emit debug line number tables only

-gmodules¶

Generate debug info with external references to clang modules or precompiled headers

Debugger to tune debug information for ¶

-ggdb¶

-glldb¶

-gsce¶

Debug information flags ¶

-gcolumn-info, -gno-column-info¶

-gdwarf-aranges¶

-gembed-source, -gno-embed-source¶

Embed source text in DWARF debug sections

-ggnu-pubnames, -gno-gnu-pubnames¶

-grecord-gcc-switches, -gno-record-gcc-switches¶

-gsplit-dwarf¶

-gstrict-dwarf, -gno-strict-dwarf¶

-gz¶

DWARF debug sections compression type

-gz=<arg>¶

DWARF debug sections compression type

Static analyzer flags ¶

Flags controlling the behavior of the Clang Static Analyzer.

-Xanalyzer <arg>¶

Pass <arg> to the static analyzer

Fortran compilation flags ¶

Flags that will be passed onto the gfortran compiler when Clang is given a Fortran input.

-A<arg>, --assert <arg>, --assert=<arg>¶

-A-<arg>¶

-J<arg>¶

-cpp¶

-faggressive-function-elimination, -fno-aggressive-function-elimination¶

-falign-commons, -fno-align-commons¶

-fall-intrinsics, -fno-all-intrinsics¶

-fautomatic, -fno-automatic¶

-fbackslash, -fno-backslash¶

-fbacktrace, -fno-backtrace¶

-fblas-matmul-limit=<arg>¶

-fbounds-check, -fno-bounds-check¶

-fcheck-array-temporaries, -fno-check-array-temporaries¶

-fcheck=<arg>¶

-fcoarray=<arg>¶

-fconvert=<arg>¶

-fcray-pointer, -fno-cray-pointer¶

-fd-lines-as-code, -fno-d-lines-as-code¶

-fd-lines-as-comments, -fno-d-lines-as-comments¶

-fdefault-double-8, -fno-default-double-8¶

-fdefault-integer-8, -fno-default-integer-8¶

-fdefault-real-8, -fno-default-real-8¶

-fdollar-ok, -fno-dollar-ok¶

-fdump-fortran-optimized, -fno-dump-fortran-optimized¶

-fdump-fortran-original, -fno-dump-fortran-original¶

-fdump-parse-tree, -fno-dump-parse-tree¶

-fexternal-blas, -fno-external-blas¶

-ff2c, -fno-f2c¶

-ffixed-form, -fno-fixed-form¶

-ffixed-line-length-<arg>¶

-ffpe-trap=<arg>¶

-ffree-form, -fno-free-form¶

-ffree-line-length-<arg>¶

-ffrontend-optimize, -fno-frontend-optimize¶

-fimplicit-none, -fno-implicit-none¶

-finit-character=<arg>¶

-finit-integer=<arg>¶

-finit-local-zero, -fno-init-local-zero¶

-finit-logical=<arg>¶

-finit-real=<arg>¶

-finteger-4-integer-8, -fno-integer-4-integer-8¶

-fintrinsic-modules-path, -fno-intrinsic-modules-path¶

-fmax-array-constructor=<arg>¶

-fmax-errors=<arg>¶

-fmax-identifier-length, -fno-max-identifier-length¶

-fmax-stack-var-size=<arg>¶

-fmax-subrecord-length=<arg>¶

-fmodule-private, -fno-module-private¶

-fpack-derived, -fno-pack-derived¶

-fprotect-parens, -fno-protect-parens¶

-frange-check, -fno-range-check¶

-freal-4-real-10, -fno-real-4-real-10¶

-freal-4-real-16, -fno-real-4-real-16¶

-freal-4-real-8, -fno-real-4-real-8¶

-freal-8-real-10, -fno-real-8-real-10¶

-freal-8-real-16, -fno-real-8-real-16¶

-freal-8-real-4, -fno-real-8-real-4¶

-frealloc-lhs, -fno-realloc-lhs¶

-frecord-marker=<arg>¶

-frecursive, -fno-recursive¶

-frepack-arrays, -fno-repack-arrays¶

-fsecond-underscore, -fno-second-underscore¶

-fsign-zero, -fno-sign-zero¶

-fstack-arrays, -fno-stack-arrays¶

-funderscoring, -fno-underscoring¶

-fwhole-file, -fno-whole-file¶

-imultilib <arg>¶

-nocpp¶

-static-libgfortran¶

Linker flags ¶

Flags that are passed on to the linker

-L<dir>, --library-directory <arg>, --library-directory=<arg>¶

Add directory to library search path

-Mach¶

-T<script>¶

Specify <script> as linker script

-Tbss<addr>¶

Set starting address of BSS to <addr>

-Tdata<addr>¶

Set starting address of DATA to <addr>

-Ttext<addr>¶

Set starting address of TEXT to <addr>

-Wl,<arg>,<arg2>...¶

Pass the comma separated arguments in <arg> to the linker

-X¶

-Xlinker <arg>, --for-linker <arg>, --for-linker=<arg>¶

Pass <arg> to the linker

-Z¶

-e<arg>, --entry¶

-filelist <arg>¶

--hip-device-lib-path=<arg>¶

HIP device library path

--hip-device-lib=<arg>¶

HIP device library

-l<arg>¶

-r¶

-rpath <arg>¶

-s¶

-t¶

-u<arg>, --force-link <arg>, --force-link=<arg>¶

-undef¶

undef all system defines

-undefined<arg>, --no-undefined¶

-z <arg>¶

Pass -z <arg> to the linker