1..
2  -------------------------------------------------------------------
3  NOTE: This file is automatically generated by running clang-tblgen
4  -gen-opt-docs. Do not edit this file by hand!!
5  -------------------------------------------------------------------
6
7=====================================
8Clang command line argument reference
9=====================================
10.. contents::
11   :local:
12
13Introduction
14============
15
16This page lists the command line arguments currently supported by the
17GCC-compatible ``clang`` and ``clang++`` drivers.
18
19
20.. program:: clang
21.. option:: -B<prefix>, --prefix <arg>, --prefix=<arg>
22
23Search $prefix$file for executables, libraries, and data files. If $prefix is a directory, search $prefix/$file
24
25.. option:: -F<arg>
26
27Add directory to framework include search path
28
29.. option:: -ObjC
30
31Treat source input files as Objective-C inputs
32
33.. program:: clang1
34.. option:: -ObjC++
35.. program:: clang
36
37Treat source input files as Objective-C++ inputs
38
39.. option:: -Qn, -fno-ident
40
41Do not emit metadata containing compiler name and version
42
43.. option:: -Qunused-arguments
44
45Don't emit warning for unused driver arguments
46
47.. option:: -Qy, -fident
48
49Emit metadata containing compiler name and version
50
51.. option:: -Wa,<arg>,<arg2>...
52
53Pass the comma separated arguments in <arg> to the assembler
54
55.. option:: -Wlarge-by-value-copy=<arg>
56
57.. option:: -Xarch\_<arg1> <arg2>
58
59.. program:: clang1
60.. option:: -Xarch\_device <arg>
61.. program:: clang
62
63Pass <arg> to the CUDA/HIP device compilation
64
65.. program:: clang2
66.. option:: -Xarch\_host <arg>
67.. program:: clang
68
69Pass <arg> to the CUDA/HIP host compilation
70
71.. option:: -Xcuda-fatbinary <arg>
72
73Pass <arg> to fatbinary invocation
74
75.. option:: -Xcuda-ptxas <arg>
76
77Pass <arg> to the ptxas assembler
78
79.. option:: -Z<arg>
80
81.. option:: -a<arg>, --profile-blocks
82
83.. option:: -all\_load
84
85.. option:: -allowable\_client <arg>
86
87.. option:: --analyze
88
89Run the static analyzer
90
91.. option:: --analyzer-no-default-checks
92
93.. option:: --analyzer-output<arg>
94
95Static analyzer report output format (html\|plist\|plist-multi-file\|plist-html\|sarif\|sarif-html\|text).
96
97.. option:: -arch <arg>
98
99.. program:: clang1
100.. option:: -arch\_errors\_fatal
101.. program:: clang
102
103.. program:: clang2
104.. option:: -arch\_only <arg>
105.. program:: clang
106
107.. option:: -arcmt-migrate-emit-errors
108
109Emit ARC errors even if the migrator can fix them
110
111.. option:: -arcmt-migrate-report-output <arg>
112
113Output path for the plist report
114
115.. option:: --autocomplete=<arg>
116
117.. option:: -bind\_at\_load
118
119.. option:: -bundle
120
121.. program:: clang1
122.. option:: -bundle\_loader <arg>
123.. program:: clang
124
125.. option:: -client\_name<arg>
126
127.. option:: -compatibility\_version<arg>
128
129.. option:: --config <arg>
130
131Specifies configuration file
132
133.. option:: --constant-cfstrings
134
135.. option:: --cuda-feature=<arg>
136
137Manually specify the CUDA feature to use
138
139.. option:: --cuda-include-ptx=<arg>, --no-cuda-include-ptx=<arg>
140
141Include PTX for the following GPU architecture (e.g. sm\_35) or 'all'. May be specified more than once.
142
143.. option:: --cuda-noopt-device-debug, --no-cuda-noopt-device-debug
144
145Enable device-side debug info generation. Disables ptxas optimizations.
146
147.. option:: -cuid=<arg>
148
149An ID for compilation unit, which should be the same for the same compilation unit but different for different compilation units. It is used to externalize device-side static variables for single source offloading languages CUDA and HIP so that they can be accessed by the host code of the same compilation unit.
150
151.. option:: -current\_version<arg>
152
153.. option:: -darwin-target-variant <arg>
154
155Generate code for an additional runtime variant of the deployment target
156
157.. option:: -darwin-target-variant-triple <arg>
158
159Specify the darwin target variant triple
160
161.. option:: -dead\_strip
162
163.. option:: -dependency-dot <arg>
164
165Filename to write DOT-formatted header dependencies to
166
167.. option:: -dependency-file <arg>
168
169Filename (or -) to write dependency output to
170
171.. option:: -dsym-dir<dir>
172
173Directory to output dSYM's (if any) to
174
175.. option:: -dumpmachine
176
177.. option:: -dumpversion
178
179.. option:: --dyld-prefix=<arg>, --dyld-prefix <arg>
180
181.. option:: -dylib\_file <arg>
182
183.. option:: -dylinker
184
185.. program:: clang1
186.. option:: -dylinker\_install\_name<arg>
187.. program:: clang
188
189.. option:: -dynamic
190
191.. option:: -dynamiclib
192
193.. option:: -emit-ast
194
195Emit Clang AST files for source inputs
196
197.. option:: --emit-static-lib
198
199Enable linker job to emit a static library.
200
201.. option:: -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
202
203Trivial automatic variable initialization to zero is only here for benchmarks, it'll eventually be removed, and I'm OK with that because I'm only using it to benchmark
204
205.. option:: --end-no-unused-arguments
206
207Start emitting warnings for unused driver arguments
208
209.. option:: -exported\_symbols\_list <arg>
210
211.. option:: -faligned-new=<arg>
212
213.. option:: -fautomatic
214
215.. option:: -ffixed-r19
216
217Reserve register r19 (Hexagon only)
218
219.. option:: -fgpu-default-stream=<arg>
220
221Specify default stream. The default value is 'legacy'. (HIP only). <arg> must be 'legacy' or 'per-thread'.
222
223.. option:: -fgpu-flush-denormals-to-zero, -fcuda-flush-denormals-to-zero, -fno-gpu-flush-denormals-to-zero
224
225Flush denormal floating point values to zero in CUDA/HIP device mode.
226
227.. option:: -fheinous-gnu-extensions
228
229.. option:: -flat\_namespace
230
231.. option:: -fopenmp-targets=<arg1>,<arg2>...
232
233Specify comma-separated list of triples OpenMP offloading targets to be supported
234
235.. option:: -force\_cpusubtype\_ALL
236
237.. program:: clang1
238.. option:: -force\_flat\_namespace
239.. program:: clang
240
241.. program:: clang2
242.. option:: -force\_load <arg>
243.. program:: clang
244
245.. option:: -fplugin-arg-<name>-<arg>
246
247Pass <arg> to plugin <name>
248
249.. option:: -framework <arg>
250
251.. option:: -frtlib-add-rpath, -fno-rtlib-add-rpath
252
253Add -rpath with architecture-specific resource directory to the linker flags
254
255.. option:: -fsanitize-system-ignorelist=<arg>, -fsanitize-system-blacklist=<arg>
256
257Path to system ignorelist file for sanitizers
258
259.. option:: -fshow-skipped-includes
260
261#include files may be "skipped" due to include guard optimization
262             or #pragma once. This flag makes -H show also such includes.
263
264.. option:: -fsystem-module
265
266Build this module as a system module. Only used with -emit-module
267
268.. option:: -fuse-cuid=<arg>
269
270Method to generate ID's for compilation units for single source offloading languages CUDA and HIP: 'hash' (ID's generated by hashing file path and command line options) \| 'random' (ID's generated as random numbers) \| 'none' (disabled). Default is 'hash'. This option will be overridden by option '-cuid=\[ID\]' if it is specified.
271
272.. option:: --gcc-toolchain=<arg>
273
274Search for GCC installation in the specified directory on targets which commonly use GCC. The directory usually contains 'lib{,32,64}/gcc{,-cross}/$triple' and 'include'. If specified, sysroot is skipped for GCC detection. Note: executables (e.g. ld) used by the compiler are not overridden by the selected GCC installation
275
276.. option:: -gcodeview
277
278Generate CodeView debug information
279
280.. option:: -gcodeview-ghash, -gno-codeview-ghash
281
282Emit type record hashes in a .debug$H section
283
284.. option:: -gen-reproducer=<arg>, -fno-crash-diagnostics (equivalent to -gen-reproducer=off)
285
286Emit reproducer on (option: off, crash (default), error, always)
287
288.. option:: --gpu-instrument-lib=<arg>
289
290Instrument device library for HIP, which is a LLVM bitcode containing \_\_cyg\_profile\_func\_enter and \_\_cyg\_profile\_func\_exit
291
292.. option:: --gpu-max-threads-per-block=<arg>
293
294Default max threads per block for kernel launch bounds for HIP
295
296.. option:: -headerpad\_max\_install\_names<arg>
297
298.. option:: -help, --help, /help<arg>, -help<arg>, --help<arg>
299
300Display available options
301
302.. option:: --help-hidden
303
304Display help for hidden options
305
306.. option:: --hip-link
307
308Link clang-offload-bundler bundles for HIP
309
310.. option:: --hip-version=<arg>
311
312HIP version in the format of major.minor.patch
313
314.. option:: -ibuiltininc
315
316Enable builtin #include directories even when -nostdinc is used before or after -ibuiltininc. Using -nobuiltininc after the option disables it
317
318.. option:: -image\_base <arg>
319
320.. option:: -index-header-map
321
322Make the next included directory (-I or -F) an indexer header map
323
324.. option:: -init <arg>
325
326.. option:: -install\_name <arg>
327
328.. option:: -interface-stub-version=<arg>
329
330.. option:: -keep\_private\_externs
331
332.. option:: -lazy\_framework <arg>
333
334.. program:: clang1
335.. option:: -lazy\_library <arg>
336.. program:: clang
337
338.. option:: -mbig-endian, -EB
339
340.. option:: -menable-unsafe-fp-math
341
342Allow unsafe floating-point math optimizations which may decrease precision
343
344.. option:: -mharden-sls=<arg>
345
346Select straight-line speculation hardening scope (ARM/AArch64/X86 only). <arg> must be: all, none, retbr(ARM/AArch64), blr(ARM/AArch64), comdat(ARM/AArch64), nocomdat(ARM/AArch64), return(X86), indirect-jmp(X86)
347
348.. option:: --migrate
349
350Run the migrator
351
352.. option:: -mios-simulator-version-min=<arg>, -miphonesimulator-version-min=<arg>
353
354.. option:: -mlinker-version=<arg>
355
356.. option:: -mlittle-endian, -EL
357
358.. option:: -mllvm <arg>
359
360Additional arguments to forward to LLVM's option processing
361
362.. option:: -mmlir <arg>
363
364Additional arguments to forward to MLIR's option processing
365
366.. option:: -module-dependency-dir <arg>
367
368Directory to dump module dependencies to
369
370.. option:: -mtvos-simulator-version-min=<arg>, -mappletvsimulator-version-min=<arg>
371
372.. option:: -multi\_module
373
374.. option:: -multiply\_defined <arg>
375
376.. program:: clang1
377.. option:: -multiply\_defined\_unused <arg>
378.. program:: clang
379
380.. option:: -mwatchos-simulator-version-min=<arg>, -mwatchsimulator-version-min=<arg>
381
382.. option:: --no-cuda-version-check
383
384Don't error out if the detected version of the CUDA install is too low for the requested CUDA gpu architecture.
385
386.. option:: -no-hip-rt
387
388Do not link against HIP runtime libraries
389
390.. option:: -no-integrated-cpp, --no-integrated-cpp
391
392.. option:: -no\_dead\_strip\_inits\_and\_terms
393
394.. option:: -nobuiltininc
395
396Disable builtin #include directories
397
398.. option:: -nodefaultlibs
399
400.. option:: -nodriverkitlib
401
402.. option:: -nofixprebinding
403
404.. option:: -nogpuinc, -nocudainc
405
406Do not add include paths for CUDA/HIP and do not include the default CUDA/HIP wrapper headers
407
408.. option:: -nogpulib, -nocudalib
409
410Do not link device library for CUDA/HIP device compilation
411
412.. option:: -nohipwrapperinc
413
414Do not include the default HIP wrapper headers and include paths
415
416.. option:: -nolibc
417
418.. option:: -nomultidefs
419
420.. option:: -nopie, -no-pie
421
422.. option:: -noprebind
423
424.. option:: -noprofilelib
425
426.. option:: -noseglinkedit
427
428.. option:: -nostdinc, --no-standard-includes
429
430.. program:: clang1
431.. option:: -nostdinc++
432.. program:: clang
433
434Disable standard #include directories for the C++ standard library
435
436.. option:: -nostdlib++
437
438.. option:: -nostdlibinc
439
440.. program:: clang1
441.. option:: -o<file>, /Fo<arg>, -Fo<arg>, --output <arg>, --output=<arg>
442.. program:: clang
443
444Write output to <file>
445
446.. option:: -objcmt-allowlist-dir-path=<arg>, -objcmt-white-list-dir-path=<arg>, -objcmt-whitelist-dir-path=<arg>
447
448Only modify files with a filename contained in the provided directory path
449
450.. option:: -objcmt-atomic-property
451
452Make migration to 'atomic' properties
453
454.. option:: -objcmt-migrate-all
455
456Enable migration to modern ObjC
457
458.. option:: -objcmt-migrate-annotation
459
460Enable migration to property and method annotations
461
462.. option:: -objcmt-migrate-designated-init
463
464Enable migration to infer NS\_DESIGNATED\_INITIALIZER for initializer methods
465
466.. option:: -objcmt-migrate-instancetype
467
468Enable migration to infer instancetype for method result type
469
470.. option:: -objcmt-migrate-literals
471
472Enable migration to modern ObjC literals
473
474.. option:: -objcmt-migrate-ns-macros
475
476Enable migration to NS\_ENUM/NS\_OPTIONS macros
477
478.. option:: -objcmt-migrate-property
479
480Enable migration to modern ObjC property
481
482.. option:: -objcmt-migrate-property-dot-syntax
483
484Enable migration of setter/getter messages to property-dot syntax
485
486.. option:: -objcmt-migrate-protocol-conformance
487
488Enable migration to add protocol conformance on classes
489
490.. option:: -objcmt-migrate-readonly-property
491
492Enable migration to modern ObjC readonly property
493
494.. option:: -objcmt-migrate-readwrite-property
495
496Enable migration to modern ObjC readwrite property
497
498.. option:: -objcmt-migrate-subscripting
499
500Enable migration to modern ObjC subscripting
501
502.. option:: -objcmt-ns-nonatomic-iosonly
503
504Enable migration to use NS\_NONATOMIC\_IOSONLY macro for setting property's 'atomic' attribute
505
506.. option:: -objcmt-returns-innerpointer-property
507
508Enable migration to annotate property with NS\_RETURNS\_INNER\_POINTER
509
510.. option:: -object
511
512.. option:: -object-file-name=<file>, -object-file-name <arg>
513
514Set the output <file> for debug infos
515
516.. option:: --offload-arch=<arg>, --cuda-gpu-arch=<arg>, --no-offload-arch=<arg>
517
518CUDA offloading device architecture (e.g. sm\_35), or HIP offloading target ID in the form of a device architecture followed by target ID features delimited by a colon. Each target ID feature is a pre-defined string followed by a plus or minus sign (e.g. gfx908:xnack+:sramecc-).  May be specified more than once.
519
520.. option:: --offload-device-only, --cuda-device-only
521
522Only compile for the offloading device.
523
524.. option:: --offload-host-device, --cuda-compile-host-device
525
526Only compile for the offloading host.
527
528.. option:: --offload-host-only, --cuda-host-only
529
530Only compile for the offloading host.
531
532.. option:: --offload=<arg1>,<arg2>...
533
534Specify comma-separated list of offloading target triples (CUDA and HIP only)
535
536.. option:: -p, --profile
537
538.. option:: -pagezero\_size<arg>
539
540.. option:: -pg
541
542Enable mcount instrumentation
543
544.. option:: -pipe, --pipe
545
546Use pipes between commands, when possible
547
548.. option:: -prebind
549
550.. program:: clang1
551.. option:: -prebind\_all\_twolevel\_modules
552.. program:: clang
553
554.. option:: -preload
555
556.. option:: --print-diagnostic-categories
557
558.. option:: -print-diagnostic-options, --print-diagnostic-options
559
560Print all of Clang's warning options
561
562.. option:: -print-effective-triple, --print-effective-triple
563
564Print the effective target triple
565
566.. option:: -print-file-name=<file>, --print-file-name=<file>, --print-file-name <arg>
567
568Print the full library path of <file>
569
570.. option:: -print-ivar-layout
571
572Enable Objective-C Ivar layout bitmap print trace
573
574.. option:: -print-libgcc-file-name, --print-libgcc-file-name
575
576Print the library path for the currently used compiler runtime library ("libgcc.a" or "libclang\_rt.builtins.\*.a")
577
578.. option:: -print-multi-directory, --print-multi-directory
579
580.. option:: -print-multi-lib, --print-multi-lib
581
582.. option:: -print-multiarch, --print-multiarch
583
584Print the multiarch target triple
585
586.. option:: -print-prog-name=<name>, --print-prog-name=<name>, --print-prog-name <arg>
587
588Print the full program path of <name>
589
590.. option:: -print-resource-dir, --print-resource-dir
591
592Print the resource directory pathname
593
594.. option:: -print-rocm-search-dirs, --print-rocm-search-dirs
595
596Print the paths used for finding ROCm installation
597
598.. option:: -print-runtime-dir, --print-runtime-dir
599
600Print the directory pathname containing clangs runtime libraries
601
602.. option:: -print-search-dirs, --print-search-dirs
603
604Print the paths used for finding libraries and programs
605
606.. option:: -print-target-triple, --print-target-triple
607
608Print the normalized target triple
609
610.. option:: -print-targets, --print-targets
611
612Print the registered targets
613
614.. option:: -private\_bundle
615
616.. option:: --product-name=<arg>
617
618.. option:: -pthread, -no-pthread
619
620Support POSIX threads in generated code
621
622.. option:: -pthreads
623
624.. option:: -read\_only\_relocs <arg>
625
626.. option:: -relocatable-pch, --relocatable-pch
627
628Whether to build a relocatable precompiled header
629
630.. option:: -remap
631
632.. option:: -rewrite-legacy-objc
633
634Rewrite Legacy Objective-C source to C++
635
636.. option:: -rtlib=<arg>, --rtlib=<arg>, --rtlib <arg>
637
638Compiler runtime library to use
639
640.. option:: -save-stats=<arg>, --save-stats=<arg>, -save-stats (equivalent to -save-stats=cwd), --save-stats (equivalent to -save-stats=cwd)
641
642Save llvm statistics.
643
644.. option:: -save-temps=<arg>, --save-temps=<arg>, -save-temps (equivalent to -save-temps=cwd), --save-temps (equivalent to -save-temps=cwd)
645
646Save intermediate compilation results.
647
648.. option:: -sectalign <arg1> <arg2> <arg3>
649
650.. option:: -sectcreate <arg1> <arg2> <arg3>
651
652.. option:: -sectobjectsymbols <arg1> <arg2>
653
654.. option:: -sectorder <arg1> <arg2> <arg3>
655
656.. option:: -seg1addr<arg>
657
658.. option:: -seg\_addr\_table <arg>
659
660.. program:: clang1
661.. option:: -seg\_addr\_table\_filename <arg>
662.. program:: clang
663
664.. option:: -segaddr <arg1> <arg2>
665
666.. option:: -segcreate <arg1> <arg2> <arg3>
667
668.. option:: -seglinkedit
669
670.. option:: -segprot <arg1> <arg2> <arg3>
671
672.. option:: -segs\_read\_<arg>
673
674.. program:: clang1
675.. option:: -segs\_read\_only\_addr <arg>
676.. program:: clang
677
678.. program:: clang2
679.. option:: -segs\_read\_write\_addr <arg>
680.. program:: clang
681
682.. option:: -serialize-diagnostics <arg>, --serialize-diagnostics <arg>
683
684Serialize compiler diagnostics to a file
685
686.. option:: -shared-libgcc
687
688.. option:: -shared-libsan, -shared-libasan
689
690Dynamically link the sanitizer runtime
691
692.. option:: -single\_module
693
694.. option:: --start-no-unused-arguments
695
696Don't emit warnings about unused arguments for the following arguments
697
698.. option:: -static-libgcc
699
700.. option:: -static-libsan
701
702Statically link the sanitizer runtime
703
704.. option:: -static-libstdc++
705
706.. option:: -static-openmp
707
708Use the static host OpenMP runtime while linking.
709
710.. option:: -std-default=<arg>
711
712.. option:: -stdlib=<arg>, --stdlib=<arg>, --stdlib <arg>
713
714C++ standard library to use. <arg> must be 'libc++', 'libstdc++' or 'platform'.
715
716.. option:: -sub\_library<arg>
717
718.. program:: clang1
719.. option:: -sub\_umbrella<arg>
720.. program:: clang
721
722.. option:: --sysroot=<arg>, --sysroot <arg>
723
724.. option:: --target-help
725
726.. option:: --target=<arg>, -target <arg>
727
728Generate code for the given target
729
730.. option:: -time
731
732Time individual commands
733
734.. option:: -traditional, --traditional
735
736.. option:: -traditional-cpp, --traditional-cpp
737
738Enable some traditional CPP emulation
739
740.. option:: -twolevel\_namespace
741
742.. program:: clang1
743.. option:: -twolevel\_namespace\_hints
744.. program:: clang
745
746.. option:: -umbrella <arg>
747
748.. option:: -unexported\_symbols\_list <arg>
749
750.. option:: -unwindlib=<arg>, --unwindlib=<arg>
751
752Unwind library to use. <arg> must be 'libgcc', 'unwindlib' or 'platform'.
753
754.. option:: -v, --verbose
755
756Show commands to run and use verbose output
757
758.. option:: --verify-debug-info
759
760Verify the binary representation of debug output
761
762.. option:: --version
763
764Print version information
765
766.. option:: -w, --no-warnings
767
768Suppress all warnings
769
770.. option:: -weak-l<arg>
771
772.. option:: -weak\_framework <arg>
773
774.. program:: clang1
775.. option:: -weak\_library <arg>
776.. program:: clang
777
778.. program:: clang2
779.. option:: -weak\_reference\_mismatches <arg>
780.. program:: clang
781
782.. option:: -whatsloaded
783
784.. option:: -why\_load, -whyload
785
786.. option:: -working-directory<arg>, -working-directory=<arg>
787
788Resolve file paths relative to the specified directory
789
790.. option:: -x<language>, --language <arg>, --language=<arg>
791
792Treat subsequent input files as having type <language>
793
794.. option:: -y<arg>
795
796Actions
797=======
798The action to perform on the input.
799
800.. option:: -E, --preprocess
801
802Only run the preprocessor
803
804.. option:: -S, --assemble
805
806Only run preprocess and compilation steps
807
808.. option:: -c, --compile
809
810Only run preprocess, compile, and assemble steps
811
812.. option:: -emit-interface-stubs
813
814Generate Interface Stub Files.
815
816.. option:: -emit-llvm
817
818Use the LLVM representation for assembler and object files
819
820.. option:: -emit-merged-ifs
821
822Generate Interface Stub Files, emit merged text not binary.
823
824.. option:: -extract-api
825
826Extract API information
827
828.. option:: -fdriver-only
829
830Only run the driver.
831
832.. option:: -fsyntax-only
833
834.. option:: -module-file-info
835
836Provide information about a particular module file
837
838.. option:: --precompile
839
840Only precompile the input
841
842.. option:: -rewrite-objc
843
844Rewrite Objective-C source to C++
845
846.. option:: -verify-pch
847
848Load and verify that a pre-compiled header file is not stale
849
850Compilation flags
851=================
852
853Flags controlling the behavior of Clang during compilation. These flags have
854no effect during actions that do not perform compilation.
855
856.. option:: -Xassembler <arg>
857
858Pass <arg> to the assembler
859
860.. option:: -Xclang <arg>
861
862Pass <arg> to the clang compiler
863
864.. option:: -Xopenmp-target <arg>
865
866Pass <arg> to the target offloading toolchain.
867
868.. program:: clang1
869.. option:: -Xopenmp-target=<triple> <arg>
870.. program:: clang
871
872Pass <arg> to the target offloading toolchain identified by <triple>.
873
874.. option:: -ansi, --ansi
875
876.. option:: -fc++-abi=<arg>
877
878C++ ABI to use. This will override the target C++ ABI.
879
880.. option:: -fclang-abi-compat=<version>
881
882Attempt to match the ABI of Clang <version>. <version> must be '<major>.<minor>' or 'latest'.
883
884.. option:: -fcomment-block-commands=<arg>,<arg2>...
885
886Treat each comma separated argument in <arg> as a documentation comment block command
887
888.. option:: -fcomplete-member-pointers, -fno-complete-member-pointers
889
890Require member pointer base types to be complete if they would be significant under the Microsoft ABI
891
892.. option:: -fcrash-diagnostics-dir=<dir>
893
894Put crash-report files in <dir>
895
896.. option:: -fdeclspec, -fno-declspec
897
898Allow \_\_declspec as a keyword
899
900.. option:: -fdepfile-entry=<arg>
901
902.. option:: -fdiagnostics-fixit-info, -fno-diagnostics-fixit-info
903
904.. option:: -fdiagnostics-format=<arg>
905
906.. option:: -fdiagnostics-parseable-fixits
907
908Print fix-its in machine parseable form
909
910.. option:: -fdiagnostics-print-source-range-info
911
912Print source range spans in numeric form
913
914.. option:: -fdiagnostics-show-category=<arg>
915
916.. option:: -fdiscard-value-names, -fno-discard-value-names
917
918Discard value names in LLVM IR
919
920.. option:: -fexperimental-relative-c++-abi-vtables, -fno-experimental-relative-c++-abi-vtables
921
922Use the experimental C++ class ABI for classes with virtual tables
923
924.. option:: -fexperimental-strict-floating-point
925
926Enables experimental strict floating point in LLVM.
927
928.. option:: -ffine-grained-bitfield-accesses, -fno-fine-grained-bitfield-accesses
929
930Use separate accesses for consecutive bitfield runs with legal widths and alignments.
931
932.. option:: -fglobal-isel, -fexperimental-isel, -fno-global-isel
933
934Enables the global instruction selector
935
936.. option:: -finline-functions, -fno-inline-functions
937
938Inline suitable functions
939
940.. option:: -finline-hint-functions
941
942Inline functions which are (explicitly or implicitly) marked inline
943
944.. option:: -fno-legacy-pass-manager, -fexperimental-new-pass-manager
945
946.. option:: -fno-sanitize-ignorelist, -fno-sanitize-blacklist
947
948Don't use ignorelist file for sanitizers
949
950.. option:: -fparse-all-comments
951
952.. option:: -frandomize-layout-seed-file=<file>
953
954File holding the seed used by the randomize structure layout feature
955
956.. option:: -frandomize-layout-seed=<seed>
957
958The seed used by the randomize structure layout feature
959
960.. option:: -frecord-command-line, -fno-record-command-line, -frecord-gcc-switches
961
962.. option:: -fsanitize-address-destructor=<arg>
963
964Set destructor type used in ASan instrumentation. <arg> must be 'none' or 'global'.
965
966.. option:: -fsanitize-address-field-padding=<arg>
967
968Level of field padding for AddressSanitizer
969
970.. option:: -fsanitize-address-globals-dead-stripping, -fno-sanitize-address-globals-dead-stripping
971
972Enable linker dead stripping of globals in AddressSanitizer
973
974.. option:: -fsanitize-address-outline-instrumentation, -fno-sanitize-address-outline-instrumentation
975
976Always generate function calls for address sanitizer instrumentation
977
978.. option:: -fsanitize-address-poison-custom-array-cookie, -fno-sanitize-address-poison-custom-array-cookie
979
980Enable poisoning array cookies when using custom operator new\[\] in AddressSanitizer
981
982.. option:: -fsanitize-address-use-after-return=<mode>
983
984Select the mode of detecting stack use-after-return in AddressSanitizer. <mode> must be 'never', 'runtime' or 'always'.
985
986.. option:: -fsanitize-address-use-after-scope, -fno-sanitize-address-use-after-scope
987
988Enable use-after-scope detection in AddressSanitizer
989
990.. option:: -fsanitize-address-use-odr-indicator, -fno-sanitize-address-use-odr-indicator
991
992Enable ODR indicator globals to avoid false ODR violation reports in partially sanitized programs at the cost of an increase in binary size
993
994.. option:: -fsanitize-cfi-canonical-jump-tables, -fno-sanitize-cfi-canonical-jump-tables
995
996Make the jump table addresses canonical in the symbol table
997
998.. option:: -fsanitize-cfi-cross-dso, -fno-sanitize-cfi-cross-dso
999
1000Enable control flow integrity (CFI) checks for cross-DSO calls.
1001
1002.. option:: -fsanitize-cfi-icall-generalize-pointers
1003
1004Generalize pointers in CFI indirect call type signature checks
1005
1006.. option:: -fsanitize-coverage-allowlist=<arg>, -fsanitize-coverage-whitelist=<arg>
1007
1008Restrict sanitizer coverage instrumentation exclusively to modules and functions that match the provided special case list, except the blocked ones
1009
1010.. option:: -fsanitize-coverage-ignorelist=<arg>, -fsanitize-coverage-blacklist=<arg>
1011
1012Disable sanitizer coverage instrumentation for modules and functions that match the provided special case list, even the allowed ones
1013
1014.. option:: -fsanitize-coverage=<arg1>,<arg2>..., -fno-sanitize-coverage=<arg1>,<arg2>...
1015
1016Specify the type of coverage instrumentation for Sanitizers
1017
1018.. option:: -fsanitize-hwaddress-abi=<arg>
1019
1020Select the HWAddressSanitizer ABI to target (interceptor or platform, default interceptor). This option is currently unused.
1021
1022.. option:: -fsanitize-hwaddress-experimental-aliasing, -fno-sanitize-hwaddress-experimental-aliasing
1023
1024Enable aliasing mode in HWAddressSanitizer
1025
1026.. option:: -fsanitize-ignorelist=<arg>, -fsanitize-blacklist=<arg>
1027
1028Path to ignorelist file for sanitizers
1029
1030.. option:: -fsanitize-link-c++-runtime, -fno-sanitize-link-c++-runtime
1031
1032.. option:: -fsanitize-link-runtime, -fno-sanitize-link-runtime
1033
1034.. option:: -fsanitize-memory-track-origins, -fno-sanitize-memory-track-origins
1035
1036Enable origins tracking in MemorySanitizer
1037
1038.. program:: clang1
1039.. option:: -fsanitize-memory-track-origins=<arg>
1040.. program:: clang
1041
1042Enable origins tracking in MemorySanitizer
1043
1044.. option:: -fsanitize-memory-use-after-dtor, -fno-sanitize-memory-use-after-dtor
1045
1046Enable use-after-destroy detection in MemorySanitizer
1047
1048.. option:: -fsanitize-memtag-mode=<arg>
1049
1050Set default MTE mode to 'sync' (default) or 'async'
1051
1052.. option:: -fsanitize-minimal-runtime, -fno-sanitize-minimal-runtime
1053
1054.. option:: -fsanitize-recover=<arg1>,<arg2>..., -fno-sanitize-recover=<arg1>,<arg2>..., -fsanitize-recover (equivalent to -fsanitize-recover=all)
1055
1056Enable recovery for specified sanitizers
1057
1058.. option:: -fsanitize-stats, -fno-sanitize-stats
1059
1060Enable sanitizer statistics gathering.
1061
1062.. option:: -fsanitize-thread-atomics, -fno-sanitize-thread-atomics
1063
1064Enable atomic operations instrumentation in ThreadSanitizer (default)
1065
1066.. option:: -fsanitize-thread-func-entry-exit, -fno-sanitize-thread-func-entry-exit
1067
1068Enable function entry/exit instrumentation in ThreadSanitizer (default)
1069
1070.. option:: -fsanitize-thread-memory-access, -fno-sanitize-thread-memory-access
1071
1072Enable memory access instrumentation in ThreadSanitizer (default)
1073
1074.. option:: -fsanitize-trap=<arg1>,<arg2>..., -fno-sanitize-trap=<arg1>,<arg2>..., -fsanitize-trap (equivalent to -fsanitize-trap=all), -fsanitize-undefined-trap-on-error (equivalent to -fsanitize-trap=undefined)
1075
1076Enable trapping for specified sanitizers
1077
1078.. option:: -fsanitize-undefined-strip-path-components=<number>
1079
1080Strip (or keep only, if negative) a given number of path components when emitting check metadata.
1081
1082.. option:: -fsanitize=<check>,<arg2>..., -fno-sanitize=<arg1>,<arg2>...
1083
1084Turn on runtime checks for various forms of undefined or suspicious behavior. See user manual for available checks
1085
1086.. option:: -moutline, -mno-outline
1087
1088Enable function outlining (AArch64 only)
1089
1090.. option:: -moutline-atomics, -mno-outline-atomics
1091
1092Generate local calls to out-of-line atomic operations
1093
1094.. option:: --param <arg>, --param=<arg>
1095
1096.. option:: -print-supported-cpus, --print-supported-cpus, -mcpu=?, -mtune=?
1097
1098Print supported cpu models for the given target (if target is not specified, it will print the supported cpus for the default target)
1099
1100.. option:: -std=<arg>, --std=<arg>, --std <arg>
1101
1102Language standard to compile for
1103
1104Preprocessor flags
1105~~~~~~~~~~~~~~~~~~
1106
1107Flags controlling the behavior of the Clang preprocessor.
1108
1109.. option:: -C, --comments
1110
1111Include comments in preprocessed output
1112
1113.. option:: -CC, --comments-in-macros
1114
1115Include comments from within macros in preprocessed output
1116
1117.. program:: clang2
1118.. option:: -D<macro>=<value>, --D<arg>, /D<arg>, -D<arg>, --define-macro <arg>, --define-macro=<arg>
1119.. program:: clang
1120
1121Define <macro> to <value> (or 1 if <value> omitted)
1122
1123.. option:: -H, --trace-includes
1124
1125Show header includes and nesting depth
1126
1127.. option:: -P, --no-line-commands
1128
1129Disable linemarker output in -E mode
1130
1131.. option:: -U<macro>, --undefine-macro <arg>, --undefine-macro=<arg>
1132
1133Undefine macro <macro>
1134
1135.. option:: -Wp,<arg>,<arg2>...
1136
1137Pass the comma separated arguments in <arg> to the preprocessor
1138
1139.. option:: -Xpreprocessor <arg>
1140
1141Pass <arg> to the preprocessor
1142
1143Include path management
1144-----------------------
1145
1146Flags controlling how ``#include``\s are resolved to files.
1147
1148.. option:: -I<dir>, --include-directory <arg>, --include-directory=<arg>
1149
1150Add directory to include search path. For C++ inputs, if
1151there are multiple -I options, these directories are searched
1152in the order they are given before the standard system directories
1153are searched. If the same directory is in the SYSTEM include search
1154paths, for example if also specified with -isystem, the -I option
1155will be ignored
1156
1157.. option:: -I-, --include-barrier
1158
1159Restrict all prior -I flags to double-quoted inclusion and remove current directory from include path
1160
1161.. option:: --amdgpu-arch-tool=<arg>
1162
1163Tool used for detecting AMD GPU arch in the system.
1164
1165.. option:: --cuda-path-ignore-env
1166
1167Ignore environment variables to detect CUDA installation
1168
1169.. option:: --cuda-path=<arg>
1170
1171CUDA installation path
1172
1173.. option:: -cxx-isystem<directory>
1174
1175Add directory to the C++ SYSTEM include search path
1176
1177.. option:: -fbuild-session-file=<file>
1178
1179Use the last modification time of <file> as the build session timestamp
1180
1181.. option:: -fbuild-session-timestamp=<time since Epoch in seconds>
1182
1183Time when the current build session started
1184
1185.. option:: -fmodule-file=\[<name>=\]<file>
1186
1187Specify the mapping of module name to precompiled module file, or load a module file if name is omitted.
1188
1189.. option:: -fmodules-cache-path=<directory>
1190
1191Specify the module cache path
1192
1193.. option:: -fmodules-disable-diagnostic-validation
1194
1195Disable validation of the diagnostic options when loading the module
1196
1197.. option:: -fmodules-prune-after=<seconds>
1198
1199Specify the interval (in seconds) after which a module file will be considered unused
1200
1201.. option:: -fmodules-prune-interval=<seconds>
1202
1203Specify the interval (in seconds) between attempts to prune the module cache
1204
1205.. option:: -fmodules-user-build-path <directory>
1206
1207Specify the module user build path
1208
1209.. option:: -fmodules-validate-once-per-build-session
1210
1211Don't verify input files for the modules if the module has been successfully validated or loaded during this build session
1212
1213.. option:: -fmodules-validate-system-headers, -fno-modules-validate-system-headers
1214
1215Validate the system headers that a module depends on when loading the module
1216
1217.. option:: -fprebuilt-module-path=<directory>
1218
1219Specify the prebuilt module path
1220
1221.. option:: --hip-path=<arg>
1222
1223HIP runtime installation path, used for finding HIP version and adding HIP include path.
1224
1225.. option:: -idirafter<arg>, --include-directory-after <arg>, --include-directory-after=<arg>
1226
1227Add directory to AFTER include search path
1228
1229.. option:: -iframework<arg>
1230
1231Add directory to SYSTEM framework search path
1232
1233.. option:: -iframeworkwithsysroot<directory>
1234
1235Add directory to SYSTEM framework search path, absolute paths are relative to -isysroot
1236
1237.. option:: -imacros<file>, --imacros<file>, --imacros=<arg>
1238
1239Include macros from file before parsing
1240
1241.. option:: -include<file>, --include<file>, --include=<arg>
1242
1243Include file before parsing
1244
1245.. option:: -include-pch <file>
1246
1247Include precompiled header file
1248
1249.. option:: -iprefix<dir>, --include-prefix <arg>, --include-prefix=<arg>
1250
1251Set the -iwithprefix/-iwithprefixbefore prefix
1252
1253.. option:: -iquote<directory>
1254
1255Add directory to QUOTE include search path
1256
1257.. option:: -isysroot<dir>
1258
1259Set the system root directory (usually /)
1260
1261.. option:: -isystem<directory>
1262
1263Add directory to SYSTEM include search path
1264
1265.. option:: -isystem-after<directory>
1266
1267Add directory to end of the SYSTEM include search path
1268
1269.. option:: -ivfsoverlay<arg>
1270
1271Overlay the virtual filesystem described by file over the real file system
1272
1273.. option:: -iwithprefix<dir>, --include-with-prefix <arg>, --include-with-prefix-after <arg>, --include-with-prefix-after=<arg>, --include-with-prefix=<arg>
1274
1275Set directory to SYSTEM include search path with prefix
1276
1277.. option:: -iwithprefixbefore<dir>, --include-with-prefix-before <arg>, --include-with-prefix-before=<arg>
1278
1279Set directory to include search path with prefix
1280
1281.. option:: -iwithsysroot<directory>
1282
1283Add directory to SYSTEM include search path, absolute paths are relative to -isysroot
1284
1285.. option:: --libomptarget-amdgpu-bc-path=<arg>, --libomptarget-amdgcn-bc-path=<arg>
1286
1287Path to libomptarget-amdgcn bitcode library
1288
1289.. option:: --libomptarget-nvptx-bc-path=<arg>
1290
1291Path to libomptarget-nvptx bitcode library
1292
1293.. option:: --ptxas-path=<arg>
1294
1295Path to ptxas (used for compiling CUDA code)
1296
1297.. option:: --rocm-path=<arg>
1298
1299ROCm installation path, used for finding and automatically linking required bitcode libraries.
1300
1301.. program:: clang1
1302.. option:: -stdlib++-isystem<directory>
1303.. program:: clang
1304
1305Use directory as the C++ standard library include path
1306
1307.. option:: --system-header-prefix=<prefix>, --no-system-header-prefix=<prefix>, --system-header-prefix <arg>
1308
1309Treat all #include paths starting with <prefix> as including a system header.
1310
1311Dependency file generation
1312--------------------------
1313
1314Flags controlling generation of a dependency file for ``make``-like build
1315systems.
1316
1317.. option:: -M, --dependencies
1318
1319Like -MD, but also implies -E and writes to stdout by default
1320
1321.. option:: -MD, --write-dependencies
1322
1323Write a depfile containing user and system headers
1324
1325.. option:: -MF<file>
1326
1327Write depfile output from -MMD, -MD, -MM, or -M to <file>
1328
1329.. option:: -MG, --print-missing-file-dependencies
1330
1331Add missing headers to depfile
1332
1333.. option:: -MJ<arg>
1334
1335Write a compilation database entry per input
1336
1337.. option:: -MM, --user-dependencies
1338
1339Like -MMD, but also implies -E and writes to stdout by default
1340
1341.. option:: -MMD, --write-user-dependencies
1342
1343Write a depfile containing user headers
1344
1345.. option:: -MP
1346
1347Create phony target for each dependency (other than main file)
1348
1349.. option:: -MQ<arg>
1350
1351Specify name of main file output to quote in depfile
1352
1353.. option:: -MT<arg>
1354
1355Specify name of main file output in depfile
1356
1357.. option:: -MV
1358
1359Use NMake/Jom format for the depfile
1360
1361Dumping preprocessor state
1362--------------------------
1363
1364Flags allowing the state of the preprocessor to be dumped in various ways.
1365
1366.. option:: -d
1367
1368.. program:: clang1
1369.. option:: -d<arg>
1370.. program:: clang
1371
1372.. option:: -dD
1373
1374Print macro definitions in -E mode in addition to normal output
1375
1376.. option:: -dI
1377
1378Print include directives in -E mode in addition to normal output
1379
1380.. option:: -dM
1381
1382Print macro definitions in -E mode instead of normal output
1383
1384Diagnostic flags
1385~~~~~~~~~~~~~~~~
1386
1387Flags controlling which warnings, errors, and remarks Clang will generate.
1388See the :doc:`full list of warning and remark flags <DiagnosticsReference>`.
1389
1390.. option:: -R<remark>
1391
1392Enable the specified remark
1393
1394.. option:: -Rpass-analysis=<arg>
1395
1396Report transformation analysis from optimization passes whose name matches the given POSIX regular expression
1397
1398.. option:: -Rpass-missed=<arg>
1399
1400Report missed transformations by optimization passes whose name matches the given POSIX regular expression
1401
1402.. option:: -Rpass=<arg>
1403
1404Report transformations performed by optimization passes whose name matches the given POSIX regular expression
1405
1406.. option:: -W<warning>, --extra-warnings, --warn-<arg>, --warn-=<arg>
1407
1408Enable the specified warning
1409
1410.. option:: -Wdeprecated, -Wno-deprecated
1411
1412Enable warnings for deprecated constructs and define \_\_DEPRECATED
1413
1414.. option:: -Wframe-larger-than=<arg>, -Wframe-larger-than
1415
1416.. option:: -Wnonportable-cfstrings<arg>, -Wno-nonportable-cfstrings<arg>
1417
1418Target-independent compilation options
1419~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1420.. option:: -fPIC, -fno-PIC
1421
1422.. option:: -fPIE, -fno-PIE
1423
1424.. option:: -faccess-control, -fno-access-control
1425
1426.. option:: -faddrsig, -fno-addrsig
1427
1428Emit an address-significance table
1429
1430.. option:: -falign-functions, -fno-align-functions
1431
1432.. program:: clang1
1433.. option:: -falign-functions=<arg>
1434.. program:: clang
1435
1436.. option:: -falign-loops=<N>
1437
1438N must be a power of two. Align loops to the boundary
1439
1440.. program:: clang1
1441.. option:: -faligned-allocation, -faligned-new, -fno-aligned-allocation
1442.. program:: clang
1443
1444Enable C++17 aligned allocation functions
1445
1446.. option:: -fallow-editor-placeholders, -fno-allow-editor-placeholders
1447
1448Treat editor placeholders as valid source code
1449
1450.. option:: -fallow-unsupported
1451
1452.. option:: -faltivec, -fno-altivec
1453
1454.. option:: -faltivec-src-compat=<arg>
1455
1456Source-level compatibility for Altivec vectors (for PowerPC targets). This includes results of vector comparison (scalar for 'xl', vector for 'gcc') as well as behavior when initializing with a scalar (splatting for 'xl', element zero only for 'gcc'). For 'mixed', the compatibility is as 'gcc' for 'vector bool/vector pixel' and as 'xl' for other types. Current default is 'mixed'. <arg> must be 'mixed', 'gcc' or 'xl'.
1457
1458.. option:: -fansi-escape-codes
1459
1460Use ANSI escape codes for diagnostics
1461
1462.. option:: -fapple-kext, -findirect-virtual-calls, -fterminated-vtables
1463
1464Use Apple's kernel extensions ABI
1465
1466.. option:: -fapple-link-rtlib
1467
1468Force linking the clang builtins runtime library
1469
1470.. option:: -fapple-pragma-pack, -fno-apple-pragma-pack
1471
1472Enable Apple gcc-compatible #pragma pack handling
1473
1474.. option:: -fapplication-extension, -fno-application-extension
1475
1476Restrict code to those available for App Extensions
1477
1478.. option:: -fapprox-func, -fno-approx-func
1479
1480Allow certain math function calls to be replaced with an approximately equivalent calculation
1481
1482.. option:: -fasm, -fno-asm
1483
1484.. option:: -fasm-blocks, -fno-asm-blocks
1485
1486.. option:: -fassociative-math, -fno-associative-math
1487
1488.. option:: -fassume-sane-operator-new, -fno-assume-sane-operator-new
1489
1490.. option:: -fast
1491
1492.. option:: -fastcp
1493
1494.. option:: -fastf
1495
1496.. option:: -fasync-exceptions, -fno-async-exceptions
1497
1498Enable EH Asynchronous exceptions
1499
1500.. option:: -fasynchronous-unwind-tables, -fno-asynchronous-unwind-tables
1501
1502.. option:: -fautolink, -fno-autolink
1503
1504.. option:: -fbasic-block-sections=<arg>
1505
1506Generate labels for each basic block or place each basic block or a subset of basic blocks in its own section. <arg> must be 'all', 'labels', 'none' or 'list='.
1507
1508.. option:: -fbinutils-version=<major.minor>
1509
1510Produced object files can use all ELF features supported by this binutils version and newer. If -fno-integrated-as is specified, the generated assembly will consider GNU as support. 'none' means that all ELF features can be used, regardless of binutils support. Defaults to 2.26.
1511
1512.. option:: -fblocks, -fno-blocks
1513
1514Enable the 'blocks' language feature
1515
1516.. option:: -fbootclasspath=<arg>, --bootclasspath <arg>, --bootclasspath=<arg>
1517
1518.. option:: -fborland-extensions, -fno-borland-extensions
1519
1520Accept non-standard constructs supported by the Borland compiler
1521
1522.. option:: -fbracket-depth=<arg>
1523
1524.. option:: -fbuiltin, -fno-builtin
1525
1526.. option:: -fbuiltin-module-map
1527
1528Load the clang builtins module map file.
1529
1530.. program:: clang1
1531.. option:: -fc++-static-destructors, -fno-c++-static-destructors
1532.. program:: clang
1533
1534.. option:: -fcaret-diagnostics, -fno-caret-diagnostics
1535
1536.. option:: -fcf-protection=<arg>, -fcf-protection (equivalent to -fcf-protection=full)
1537
1538Instrument control-flow architecture protection. <arg> must be 'return', 'branch', 'full' or 'none'.
1539
1540.. option:: -fcf-runtime-abi=<arg>
1541
1542 <arg> must be 'unspecified', 'standalone', 'objc', 'swift', 'swift-5.0', 'swift-4.2' or 'swift-4.1'.
1543
1544.. option:: -fchar8\_t, -fno-char8\_t
1545
1546Enable C++ builtin type char8\_t
1547
1548.. option:: -fclasspath=<arg>, --CLASSPATH <arg>, --CLASSPATH=<arg>, --classpath <arg>, --classpath=<arg>
1549
1550.. option:: -fcolor-diagnostics, -fdiagnostics-color, -fno-color-diagnostics
1551
1552Enable colors in diagnostics
1553
1554.. option:: -fcommon, -fno-common
1555
1556Place uninitialized global variables in a common block
1557
1558.. option:: -fcompile-resource=<arg>, --resource <arg>, --resource=<arg>
1559
1560.. option:: -fconstant-cfstrings, -fno-constant-cfstrings
1561
1562.. option:: -fconstant-string-class=<arg>
1563
1564.. option:: -fconstexpr-backtrace-limit=<arg>
1565
1566.. option:: -fconstexpr-depth=<arg>
1567
1568.. option:: -fconstexpr-steps=<arg>
1569
1570.. option:: -fconvergent-functions
1571
1572Assume functions may be convergent
1573
1574.. option:: -fcoroutines-ts, -fno-coroutines-ts
1575
1576Enable support for the C++ Coroutines TS
1577
1578.. option:: -fcoverage-compilation-dir=<arg>
1579
1580The compilation directory to embed in the coverage mapping.
1581
1582.. option:: -fcoverage-mapping, -fno-coverage-mapping
1583
1584Generate coverage mapping to enable code coverage analysis
1585
1586.. option:: -fcoverage-prefix-map=<arg>
1587
1588remap file source paths in coverage mapping
1589
1590.. option:: -fcreate-profile
1591
1592.. option:: -fcs-profile-generate
1593
1594Generate instrumented code to collect context sensitive execution counts into default.profraw (overridden by LLVM\_PROFILE\_FILE env var)
1595
1596.. program:: clang1
1597.. option:: -fcs-profile-generate=<directory>
1598.. program:: clang
1599
1600Generate instrumented code to collect context sensitive execution counts into <directory>/default.profraw (overridden by LLVM\_PROFILE\_FILE env var)
1601
1602.. option:: -fcuda-approx-transcendentals, -fno-cuda-approx-transcendentals
1603
1604Use approximate transcendental functions
1605
1606.. option:: -fcuda-short-ptr, -fno-cuda-short-ptr
1607
1608Use 32-bit pointers for accessing const/local/shared address spaces
1609
1610.. option:: -fcxx-exceptions, -fno-cxx-exceptions
1611
1612Enable C++ exceptions
1613
1614.. option:: -fcxx-modules, -fno-cxx-modules
1615
1616Enable modules for C++
1617
1618.. option:: -fdata-sections, -fno-data-sections
1619
1620Place each data in its own section
1621
1622.. option:: -fdebug-compilation-dir=<arg>, -fdebug-compilation-dir <arg>
1623
1624The compilation directory to embed in the debug info
1625
1626.. option:: -fdebug-default-version=<arg>
1627
1628Default DWARF version to use, if a -g option caused DWARF debug info to be produced
1629
1630.. option:: -fdebug-info-for-profiling, -fno-debug-info-for-profiling
1631
1632Emit extra debug info to make sample profile more accurate
1633
1634.. option:: -fdebug-macro, -fno-debug-macro
1635
1636Emit macro debug information
1637
1638.. option:: -fdebug-pass-arguments
1639
1640.. option:: -fdebug-pass-structure
1641
1642.. option:: -fdebug-prefix-map=<arg>
1643
1644remap file source paths in debug info
1645
1646.. option:: -fdebug-ranges-base-address, -fno-debug-ranges-base-address
1647
1648Use DWARF base address selection entries in .debug\_ranges
1649
1650.. option:: -fdebug-types-section, -fno-debug-types-section
1651
1652Place debug types in their own section (ELF Only)
1653
1654.. option:: -fdelayed-template-parsing, -fno-delayed-template-parsing
1655
1656Parse templated function definitions at the end of the translation unit
1657
1658.. option:: -fdelete-null-pointer-checks, -fno-delete-null-pointer-checks
1659
1660Treat usage of null pointers as undefined behavior (default)
1661
1662.. option:: -fdenormal-fp-math=<arg>
1663
1664.. option:: -fdiagnostics-absolute-paths
1665
1666Print absolute paths in diagnostics
1667
1668.. program:: clang1
1669.. option:: -fdiagnostics-color=<arg>
1670.. program:: clang
1671
1672.. option:: -fdiagnostics-hotness-threshold=<value>
1673
1674Prevent optimization remarks from being output if they do not have at least this profile count. Use 'auto' to apply the threshold from profile summary
1675
1676.. option:: -fdiagnostics-misexpect-tolerance=<value>
1677
1678Prevent misexpect diagnostics from being output if the profile counts are within N% of the expected.
1679
1680.. option:: -fdiagnostics-show-hotness, -fno-diagnostics-show-hotness
1681
1682Enable profile hotness information in diagnostic line
1683
1684.. option:: -fdiagnostics-show-note-include-stack, -fno-diagnostics-show-note-include-stack
1685
1686Display include stacks for diagnostic notes
1687
1688.. option:: -fdiagnostics-show-option, -fno-diagnostics-show-option
1689
1690Print option name with mappable diagnostics
1691
1692.. option:: -fdiagnostics-show-template-tree
1693
1694Print a template comparison tree for differing templates
1695
1696.. option:: -fdigraphs, -fno-digraphs
1697
1698Enable alternative token representations '<:', ':>', '<%', '%>', '%:', '%:%:' (default)
1699
1700.. option:: -fdirect-access-external-data, -fno-direct-access-external-data
1701
1702Don't use GOT indirection to reference external data symbols
1703
1704.. option:: -fdirectives-only, -fno-directives-only
1705
1706.. option:: -fdollars-in-identifiers, -fno-dollars-in-identifiers
1707
1708Allow '$' in identifiers
1709
1710.. option:: -fdouble-square-bracket-attributes, -fno-double-square-bracket-attributes
1711
1712Enable '\[\[\]\]' attributes in all C and C++ language modes
1713
1714.. option:: -fdwarf-directory-asm, -fno-dwarf-directory-asm
1715
1716.. option:: -fdwarf-exceptions
1717
1718Use DWARF style exceptions
1719
1720.. option:: -felide-constructors, -fno-elide-constructors
1721
1722.. option:: -feliminate-unused-debug-symbols, -fno-eliminate-unused-debug-symbols
1723
1724.. option:: -feliminate-unused-debug-types, -fno-eliminate-unused-debug-types
1725
1726Do not emit  debug info for defined but unused types
1727
1728.. option:: -fembed-bitcode=<option>, -fembed-bitcode (equivalent to -fembed-bitcode=all), -fembed-bitcode-marker (equivalent to -fembed-bitcode=marker)
1729
1730Embed LLVM bitcode. <option> must be 'off', 'all', 'bitcode' or 'marker'.
1731
1732.. option:: -fembed-offload-object=<arg>
1733
1734Embed Offloading device-side binary into host object file as a section.
1735
1736.. option:: -femit-all-decls
1737
1738Emit all declarations, even if unused
1739
1740.. option:: -femit-dwarf-unwind=<arg>
1741
1742When to emit DWARF unwind (EH frame) info. <arg> must be 'always', 'no-compact-unwind' or 'default'.
1743
1744.. option:: -femulated-tls, -fno-emulated-tls
1745
1746Use emutls functions to access thread\_local variables
1747
1748.. option:: -fenable-matrix
1749
1750Enable matrix data type and related builtin functions
1751
1752.. option:: -fencoding=<arg>, --encoding <arg>, --encoding=<arg>
1753
1754.. option:: -ferror-limit=<arg>
1755
1756.. option:: -fescaping-block-tail-calls, -fno-escaping-block-tail-calls
1757
1758.. option:: -fexceptions, -fno-exceptions
1759
1760Enable support for exception handling
1761
1762.. option:: -fexec-charset=<arg>
1763
1764.. option:: -fexperimental-new-constant-interpreter
1765
1766Enable the experimental new constant interpreter
1767
1768.. option:: -fextdirs=<arg>, --extdirs <arg>, --extdirs=<arg>
1769
1770.. option:: -fextend-arguments=<arg>
1771
1772Controls how scalar integer arguments are extended in calls to unprototyped and varargs functions. <arg> must be '32' or '64'.
1773
1774.. option:: -ffast-math, -fno-fast-math
1775
1776Allow aggressive, lossy floating-point optimizations
1777
1778.. option:: -ffile-compilation-dir=<arg>
1779
1780The compilation directory to embed in the debug info and coverage mapping.
1781
1782.. option:: -ffile-prefix-map=<arg>
1783
1784remap file source paths in debug info, predefined preprocessor macros and \_\_builtin\_FILE(). Implies -ffile-reproducible.
1785
1786.. option:: -ffile-reproducible, -fno-file-reproducible
1787
1788Use the target's platform-specific path separator character when expanding the \_\_FILE\_\_ macro
1789
1790.. option:: -ffinite-loops, -fno-finite-loops
1791
1792Assume all loops are finite.
1793
1794.. option:: -ffinite-math-only, -fno-finite-math-only
1795
1796.. option:: -ffixed-point, -fno-fixed-point
1797
1798Enable fixed point types
1799
1800.. option:: -ffor-scope, -fno-for-scope
1801
1802.. option:: -fforce-dwarf-frame, -fno-force-dwarf-frame
1803
1804Always emit a debug frame section
1805
1806.. option:: -fforce-emit-vtables, -fno-force-emit-vtables
1807
1808Emits more virtual tables to improve devirtualization
1809
1810.. option:: -fforce-enable-int128, -fno-force-enable-int128
1811
1812Enable support for int128\_t type
1813
1814.. option:: -ffp-contract=<arg>
1815
1816Form fused FP ops (e.g. FMAs): fast (fuses across statements disregarding pragmas) \| on (only fuses in the same statement unless dictated by pragmas) \| off (never fuses) \| fast-honor-pragmas (fuses across statements unless diectated by pragmas). Default is 'fast' for CUDA, 'fast-honor-pragmas' for HIP, and 'on' otherwise. <arg> must be 'fast', 'on', 'off' or 'fast-honor-pragmas'.
1817
1818.. option:: -ffp-eval-method=<arg>
1819
1820Specifies the evaluation method to use for floating-point arithmetic. <arg> must be 'source', 'double' or 'extended'.
1821
1822.. option:: -ffp-exception-behavior=<arg>
1823
1824Specifies the exception behavior of floating-point operations. <arg> must be 'ignore', 'maytrap' or 'strict'.
1825
1826.. option:: -ffp-model=<arg>
1827
1828Controls the semantics of floating-point calculations.
1829
1830.. option:: -ffreestanding
1831
1832Assert that the compilation takes place in a freestanding environment
1833
1834.. option:: -ffunction-sections, -fno-function-sections
1835
1836Place each function in its own section
1837
1838.. option:: -fgnu-inline-asm, -fno-gnu-inline-asm
1839
1840.. option:: -fgnu-keywords, -fno-gnu-keywords
1841
1842Allow GNU-extension keywords regardless of language standard
1843
1844.. option:: -fgnu-runtime
1845
1846Generate output compatible with the standard GNU Objective-C runtime
1847
1848.. option:: -fgnu89-inline, -fno-gnu89-inline
1849
1850Use the gnu89 inline semantics
1851
1852.. option:: -fgnuc-version=<arg>
1853
1854Sets various macros to claim compatibility with the given GCC version (default is 4.2.1)
1855
1856.. option:: -fgpu-allow-device-init, -fno-gpu-allow-device-init
1857
1858Allow device side init function in HIP (experimental)
1859
1860.. option:: -fgpu-defer-diag, -fno-gpu-defer-diag
1861
1862Defer host/device related diagnostic messages for CUDA/HIP
1863
1864.. option:: -fgpu-rdc, -fcuda-rdc, -fno-gpu-rdc
1865
1866Generate relocatable device code, also known as separate compilation mode
1867
1868.. option:: -fgpu-sanitize, -fno-gpu-sanitize
1869
1870Enable sanitizer for AMDGPU target
1871
1872.. option:: -fhip-fp32-correctly-rounded-divide-sqrt, -fno-hip-fp32-correctly-rounded-divide-sqrt
1873
1874Specify that single precision floating-point divide and sqrt used in the program source are correctly rounded (HIP device compilation only)
1875
1876.. option:: -fhip-new-launch-api, -fno-hip-new-launch-api
1877
1878Use new kernel launching API for HIP
1879
1880.. option:: -fhonor-infinities, -fhonor-infinites, -fno-honor-infinities
1881
1882.. option:: -fhonor-nans, -fno-honor-nans
1883
1884.. option:: -fhosted
1885
1886.. option:: -fignore-exceptions
1887
1888Enable support for ignoring exception handling constructs
1889
1890.. option:: -fimplicit-module-maps, -fmodule-maps, -fno-implicit-module-maps
1891
1892Implicitly search the file system for module map files.
1893
1894.. option:: -fimplicit-modules, -fno-implicit-modules
1895
1896.. option:: -finput-charset=<arg>
1897
1898Specify the default character set for source files
1899
1900.. option:: -finstrument-function-entry-bare
1901
1902Instrument function entry only, after inlining, without arguments to the instrumentation call
1903
1904.. option:: -finstrument-functions
1905
1906Generate calls to instrument function entry and exit
1907
1908.. option:: -finstrument-functions-after-inlining
1909
1910Like -finstrument-functions, but insert the calls after inlining
1911
1912.. option:: -fintegrated-as, -fno-integrated-as, -integrated-as
1913
1914Enable the integrated assembler
1915
1916.. option:: -fintegrated-cc1, -fno-integrated-cc1
1917
1918Run cc1 in-process
1919
1920.. option:: -fintegrated-objemitter, -fno-integrated-objemitter
1921
1922Use internal machine object code emitter.
1923
1924.. option:: -fjmc, -fno-jmc
1925
1926Enable just-my-code debugging
1927
1928.. option:: -fjump-tables, -fno-jump-tables
1929
1930Use jump tables for lowering switches
1931
1932.. option:: -fkeep-static-consts, -fno-keep-static-consts
1933
1934Keep static const variables if unused
1935
1936.. option:: -flax-vector-conversions=<arg>, -flax-vector-conversions (equivalent to -flax-vector-conversions=integer), -fno-lax-vector-conversions (equivalent to -flax-vector-conversions=none)
1937
1938Enable implicit vector bit-casts. <arg> must be 'none', 'integer' or 'all'.
1939
1940.. option:: -flimited-precision=<arg>
1941
1942.. option:: -flto-jobs=<arg>
1943
1944Controls the backend parallelism of -flto=thin (default of 0 means the number of threads will be derived from the number of CPUs detected)
1945
1946.. option:: -flto=<arg>, -flto (equivalent to -flto=full), -flto=auto (equivalent to -flto=full), -flto=jobserver (equivalent to -flto=full)
1947
1948Set LTO mode. <arg> must be 'thin' or 'full'.
1949
1950.. option:: -fmacro-backtrace-limit=<arg>
1951
1952.. option:: -fmacro-prefix-map=<arg>
1953
1954remap file source paths in predefined preprocessor macros and \_\_builtin\_FILE(). Implies -ffile-reproducible.
1955
1956.. option:: -fmath-errno, -fno-math-errno
1957
1958Require math functions to indicate errors by setting errno
1959
1960.. option:: -fmax-tokens=<arg>
1961
1962Max total number of preprocessed tokens for -Wmax-tokens.
1963
1964.. option:: -fmax-type-align=<arg>
1965
1966Specify the maximum alignment to enforce on pointers lacking an explicit alignment
1967
1968.. option:: -fmemory-profile, -fno-memory-profile
1969
1970Enable heap memory profiling
1971
1972.. program:: clang1
1973.. option:: -fmemory-profile=<directory>
1974.. program:: clang
1975
1976Enable heap memory profiling and dump results into <directory>
1977
1978.. option:: -fmerge-all-constants, -fno-merge-all-constants
1979
1980Allow merging of constants
1981
1982.. option:: -fmessage-length=<arg>
1983
1984Format message diagnostics so that they fit within N columns
1985
1986.. option:: -fminimize-whitespace, -fno-minimize-whitespace
1987
1988Minimize whitespace when emitting preprocessor output
1989
1990.. option:: -fmodule-file-deps, -fno-module-file-deps
1991
1992.. option:: -fmodule-header
1993
1994Build a C++20 Header Unit from a header.
1995
1996.. program:: clang1
1997.. option:: -fmodule-header=<kind>
1998.. program:: clang
1999
2000Build a C++20 Header Unit from a header that should be found in the user (fmodule-header=user) or system (fmodule-header=system) search path.
2001
2002.. option:: -fmodule-map-file=<file>
2003
2004Load this module map file
2005
2006.. option:: -fmodule-name=<name>, -fmodule-implementation-of <arg>
2007
2008Specify the name of the module to build
2009
2010.. option:: -fmodules, -fno-modules
2011
2012Enable the 'modules' language feature
2013
2014.. option:: -fmodules-decluse, -fno-modules-decluse
2015
2016Require declaration of modules used within a module
2017
2018.. option:: -fmodules-ignore-macro=<arg>
2019
2020Ignore the definition of the given macro when building and loading modules
2021
2022.. option:: -fmodules-search-all, -fno-modules-search-all
2023
2024Search even non-imported modules to resolve references
2025
2026.. option:: -fmodules-strict-decluse
2027
2028Like -fmodules-decluse but requires all headers to be in modules
2029
2030.. option:: -fmodules-ts
2031
2032Enable support for the C++ Modules TS
2033
2034.. option:: -fmodules-validate-input-files-content
2035
2036Validate PCM input files based on content if mtime differs
2037
2038.. option:: -fms-compatibility, -fno-ms-compatibility
2039
2040Enable full Microsoft Visual C++ compatibility
2041
2042.. option:: -fms-compatibility-version=<arg>
2043
2044Dot-separated value representing the Microsoft compiler version number to report in \_MSC\_VER (0 = don't define it (default))
2045
2046.. option:: -fms-extensions, -fno-ms-extensions
2047
2048Accept some non-standard constructs supported by the Microsoft compiler
2049
2050.. option:: -fms-hotpatch
2051
2052Ensure that all functions can be hotpatched at runtime
2053
2054.. option:: -fms-memptr-rep=<arg>
2055
2056 <arg> must be 'single', 'multiple' or 'virtual'.
2057
2058.. option:: -fms-volatile
2059
2060.. option:: -fmsc-version=<arg>
2061
2062Microsoft compiler version number to report in \_MSC\_VER (0 = don't define it (default))
2063
2064.. option:: -fmudflap
2065
2066.. option:: -fmudflapth
2067
2068.. option:: -fnested-functions
2069
2070.. option:: -fnew-alignment=<align>, -fnew-alignment <arg>
2071
2072Specifies the largest alignment guaranteed by '::operator new(size\_t)'
2073
2074.. option:: -fnew-infallible, -fno-new-infallible
2075
2076Enable treating throwing global C++ operator new as always returning valid memory (annotates with \_\_attribute\_\_((returns\_nonnull)) and throw()). This is detectable in source.
2077
2078.. option:: -fnext-runtime
2079
2080.. option:: -fno-builtin-<arg>
2081
2082Disable implicit builtin knowledge of a specific function
2083
2084.. option:: -fno-elide-type
2085
2086Do not elide types when printing diagnostics
2087
2088.. option:: -fno-knr-functions
2089
2090Disable support for K&R C function declarations
2091
2092.. option:: -fno-max-type-align
2093
2094.. option:: -fno-strict-modules-decluse
2095
2096.. option:: -fno-temp-file
2097
2098Directly create compilation output files. This may lead to incorrect incremental builds if the compiler crashes
2099
2100.. option:: -fno-working-directory
2101
2102.. option:: -fno\_modules-validate-input-files-content
2103
2104.. program:: clang1
2105.. option:: -fno\_pch-validate-input-files-content
2106.. program:: clang
2107
2108.. option:: -fnoxray-link-deps
2109
2110.. option:: -fobjc-abi-version=<arg>
2111
2112.. option:: -fobjc-arc, -fno-objc-arc
2113
2114Synthesize retain and release calls for Objective-C pointers
2115
2116.. option:: -fobjc-arc-exceptions, -fno-objc-arc-exceptions
2117
2118Use EH-safe code when synthesizing retains and releases in -fobjc-arc
2119
2120.. option:: -fobjc-convert-messages-to-runtime-calls, -fno-objc-convert-messages-to-runtime-calls
2121
2122.. option:: -fobjc-disable-direct-methods-for-testing
2123
2124Ignore attribute objc\_direct so that direct methods can be tested
2125
2126.. option:: -fobjc-encode-cxx-class-template-spec, -fno-objc-encode-cxx-class-template-spec
2127
2128Fully encode c++ class template specialization
2129
2130.. option:: -fobjc-exceptions, -fno-objc-exceptions
2131
2132Enable Objective-C exceptions
2133
2134.. option:: -fobjc-infer-related-result-type, -fno-objc-infer-related-result-type
2135
2136.. option:: -fobjc-legacy-dispatch, -fno-objc-legacy-dispatch
2137
2138.. option:: -fobjc-link-runtime
2139
2140.. option:: -fobjc-nonfragile-abi, -fno-objc-nonfragile-abi
2141
2142.. option:: -fobjc-nonfragile-abi-version=<arg>
2143
2144.. option:: -fobjc-runtime=<arg>
2145
2146Specify the target Objective-C runtime kind and version
2147
2148.. option:: -fobjc-sender-dependent-dispatch
2149
2150.. option:: -fobjc-weak, -fno-objc-weak
2151
2152Enable ARC-style weak references in Objective-C
2153
2154.. option:: -foffload-lto=<arg>, -foffload-lto (equivalent to -foffload-lto=full)
2155
2156Set LTO mode for offload compilation. <arg> must be 'thin' or 'full'.
2157
2158.. option:: -fomit-frame-pointer, -fno-omit-frame-pointer
2159
2160.. option:: -fopenmp, -fno-openmp
2161
2162Parse OpenMP pragmas and generate parallel code.
2163
2164.. option:: -fopenmp-extensions, -fno-openmp-extensions
2165
2166Enable all Clang extensions for OpenMP directives and clauses
2167
2168.. option:: -fopenmp-implicit-rpath, -fno-openmp-implicit-rpath
2169
2170Set rpath on OpenMP executables
2171
2172.. option:: -fopenmp-new-driver
2173
2174Use the new driver for OpenMP offloading.
2175
2176.. option:: -fopenmp-offload-mandatory
2177
2178Do not create a host fallback if offloading to the device fails.
2179
2180.. option:: -fopenmp-simd, -fno-openmp-simd
2181
2182Emit OpenMP code only for SIMD-based constructs.
2183
2184.. option:: -fopenmp-target-debug, -fno-openmp-target-debug
2185
2186Enable debugging in the OpenMP offloading device RTL
2187
2188.. option:: -fopenmp-version=<arg>
2189
2190Set OpenMP version (e.g. 45 for OpenMP 4.5, 50 for OpenMP 5.0). Default value is 50.
2191
2192.. program:: clang1
2193.. option:: -fopenmp=<arg>
2194.. program:: clang
2195
2196.. option:: -foperator-arrow-depth=<arg>
2197
2198.. option:: -foperator-names, -fno-operator-names
2199
2200.. option:: -foptimization-record-file=<file>
2201
2202Specify the output name of the file containing the optimization remarks. Implies -fsave-optimization-record. On Darwin platforms, this cannot be used with multiple -arch <arch> options.
2203
2204.. option:: -foptimization-record-passes=<regex>
2205
2206Only include passes which match a specified regular expression in the generated optimization record (by default, include all passes)
2207
2208.. option:: -foptimize-sibling-calls, -fno-optimize-sibling-calls
2209
2210.. option:: -forder-file-instrumentation
2211
2212Generate instrumented code to collect order file into default.profraw file (overridden by '=' form of option or LLVM\_PROFILE\_FILE env var)
2213
2214.. option:: -foutput-class-dir=<arg>, --output-class-directory <arg>, --output-class-directory=<arg>
2215
2216.. option:: -fpack-struct, -fno-pack-struct
2217
2218.. program:: clang1
2219.. option:: -fpack-struct=<arg>
2220.. program:: clang
2221
2222Specify the default maximum struct packing alignment
2223
2224.. option:: -fpascal-strings, -fno-pascal-strings, -mpascal-strings
2225
2226Recognize and construct Pascal-style string literals
2227
2228.. option:: -fpass-plugin=<dsopath>
2229
2230Load pass plugin from a dynamic shared object file (only with new pass manager).
2231
2232.. option:: -fpatchable-function-entry=<N,M>
2233
2234Generate M NOPs before function entry and N-M NOPs after function entry
2235
2236.. option:: -fpcc-struct-return
2237
2238Override the default ABI to return all structs on the stack
2239
2240.. option:: -fpch-codegen, -fno-pch-codegen
2241
2242Generate code for uses of this PCH that assumes an explicit object file will be built for the PCH
2243
2244.. option:: -fpch-debuginfo, -fno-pch-debuginfo
2245
2246Generate debug info for types in an object file built from this PCH and do not generate them elsewhere
2247
2248.. option:: -fpch-instantiate-templates, -fno-pch-instantiate-templates
2249
2250Instantiate templates already while building a PCH
2251
2252.. option:: -fpch-preprocess
2253
2254.. option:: -fpch-validate-input-files-content
2255
2256Validate PCH input files based on content if mtime differs
2257
2258.. option:: -fpic, -fno-pic
2259
2260.. option:: -fpie, -fno-pie
2261
2262.. option:: -fplt, -fno-plt
2263
2264.. option:: -fplugin=<dsopath>
2265
2266Load the named plugin (dynamic shared object)
2267
2268.. option:: -fprebuilt-implicit-modules, -fno-prebuilt-implicit-modules
2269
2270Look up implicit modules in the prebuilt module path
2271
2272.. option:: -fpreserve-as-comments, -fno-preserve-as-comments
2273
2274.. option:: -fproc-stat-report<arg>
2275
2276Print subprocess statistics
2277
2278.. program:: clang1
2279.. option:: -fproc-stat-report=<arg>
2280.. program:: clang
2281
2282Save subprocess statistics to the given file
2283
2284.. option:: -fprofile-arcs, -fno-profile-arcs
2285
2286.. option:: -fprofile-dir=<arg>
2287
2288.. option:: -fprofile-exclude-files=<arg>
2289
2290Instrument only functions from files where names don't match all the regexes separated by a semi-colon
2291
2292.. option:: -fprofile-filter-files=<arg>
2293
2294Instrument only functions from files where names match any regex separated by a semi-colon
2295
2296.. option:: -fprofile-generate, -fno-profile-generate
2297
2298Generate instrumented code to collect execution counts into default.profraw (overridden by LLVM\_PROFILE\_FILE env var)
2299
2300.. program:: clang1
2301.. option:: -fprofile-generate=<directory>
2302.. program:: clang
2303
2304Generate instrumented code to collect execution counts into <directory>/default.profraw (overridden by LLVM\_PROFILE\_FILE env var)
2305
2306.. option:: -fprofile-instr-generate, -fno-profile-instr-generate
2307
2308Generate instrumented code to collect execution counts into default.profraw file (overridden by '=' form of option or LLVM\_PROFILE\_FILE env var)
2309
2310.. program:: clang1
2311.. option:: -fprofile-instr-generate=<file>
2312.. program:: clang
2313
2314Generate instrumented code to collect execution counts into <file> (overridden by LLVM\_PROFILE\_FILE env var)
2315
2316.. option:: -fprofile-instr-use, -fno-profile-instr-use, -fprofile-use
2317
2318.. program:: clang1
2319.. option:: -fprofile-instr-use=<arg>
2320.. program:: clang
2321
2322Use instrumentation data for profile-guided optimization
2323
2324.. option:: -fprofile-list=<arg>
2325
2326Filename defining the list of functions/files to instrument
2327
2328.. option:: -fprofile-remapping-file=<file>
2329
2330Use the remappings described in <file> to match the profile data against names in the program
2331
2332.. option:: -fprofile-sample-accurate, -fauto-profile-accurate, -fno-profile-sample-accurate
2333
2334Specifies that the sample profile is accurate. If the sample
2335               profile is accurate, callsites without profile samples are marked
2336               as cold. Otherwise, treat callsites without profile samples as if
2337               we have no profile
2338
2339.. option:: -fprofile-sample-use, -fauto-profile, -fno-profile-sample-use
2340
2341.. program:: clang1
2342.. option:: -fprofile-sample-use=<arg>, -fauto-profile=<arg>
2343.. program:: clang
2344
2345Enable sample-based profile guided optimizations
2346
2347.. option:: -fprofile-update=<method>
2348
2349Set update method of profile counters. <method> must be 'atomic', 'prefer-atomic' or 'single'.
2350
2351.. program:: clang1
2352.. option:: -fprofile-use=<pathname>
2353.. program:: clang
2354
2355Use instrumentation data for profile-guided optimization. If pathname is a directory, it reads from <pathname>/default.profdata. Otherwise, it reads from file <pathname>.
2356
2357.. option:: -fprotect-parens, -fno-protect-parens
2358
2359Determines whether the optimizer honors parentheses when floating-point expressions are evaluated
2360
2361.. option:: -fpseudo-probe-for-profiling, -fno-pseudo-probe-for-profiling
2362
2363Emit pseudo probes for sample profiling
2364
2365.. option:: -freciprocal-math, -fno-reciprocal-math
2366
2367Allow division operations to be reassociated
2368
2369.. option:: -freg-struct-return
2370
2371Override the default ABI to return small structs in registers
2372
2373.. option:: -fregister-global-dtors-with-atexit, -fno-register-global-dtors-with-atexit
2374
2375Use atexit or \_\_cxa\_atexit to register global destructors
2376
2377.. option:: -frelaxed-template-template-args, -fno-relaxed-template-template-args
2378
2379Enable C++17 relaxed template template argument matching
2380
2381.. option:: -freroll-loops, -fno-reroll-loops
2382
2383Turn on loop reroller
2384
2385.. option:: -fretain-comments-from-system-headers
2386
2387.. option:: -frewrite-imports, -fno-rewrite-imports
2388
2389.. option:: -frewrite-includes, -fno-rewrite-includes
2390
2391.. option:: -frewrite-map-file=<arg>
2392
2393.. option:: -fropi, -fno-ropi
2394
2395Generate read-only position independent code (ARM only)
2396
2397.. option:: -frounding-math, -fno-rounding-math
2398
2399.. option:: -frtti, -fno-rtti
2400
2401.. option:: -frtti-data, -fno-rtti-data
2402
2403.. option:: -frwpi, -fno-rwpi
2404
2405Generate read-write position independent code (ARM only)
2406
2407.. option:: -fsanitize-memory-param-retval, -fno-sanitize-memory-param-retval
2408
2409Enable detection of uninitialized parameters and return values
2410
2411.. option:: -fsave-optimization-record, -fno-save-optimization-record
2412
2413Generate a YAML optimization record file
2414
2415.. program:: clang1
2416.. option:: -fsave-optimization-record=<format>
2417.. program:: clang
2418
2419Generate an optimization record file in a specific format
2420
2421.. option:: -fseh-exceptions
2422
2423Use SEH style exceptions
2424
2425.. option:: -fsemantic-interposition, -fno-semantic-interposition
2426
2427.. option:: -fshort-enums, -fno-short-enums
2428
2429Allocate to an enum type only as many bytes as it needs for the declared range of possible values
2430
2431.. option:: -fshort-wchar, -fno-short-wchar
2432
2433Force wchar\_t to be a short unsigned int
2434
2435.. option:: -fshow-column, -fno-show-column
2436
2437.. option:: -fshow-overloads=<arg>
2438
2439Which overload candidates to show when overload resolution fails. Defaults to 'all'. <arg> must be 'best' or 'all'.
2440
2441.. option:: -fshow-source-location, -fno-show-source-location
2442
2443.. option:: -fsignaling-math, -fno-signaling-math
2444
2445.. option:: -fsigned-bitfields
2446
2447.. option:: -fsigned-char, -fno-signed-char, --signed-char
2448
2449char is signed
2450
2451.. option:: -fsigned-zeros, -fno-signed-zeros
2452
2453.. option:: -fsized-deallocation, -fno-sized-deallocation
2454
2455Enable C++14 sized global deallocation functions
2456
2457.. option:: -fsjlj-exceptions
2458
2459Use SjLj style exceptions
2460
2461.. option:: -fslp-vectorize, -fno-slp-vectorize, -ftree-slp-vectorize
2462
2463Enable the superword-level parallelism vectorization passes
2464
2465.. option:: -fspell-checking, -fno-spell-checking
2466
2467.. option:: -fspell-checking-limit=<arg>
2468
2469.. option:: -fsplit-dwarf-inlining, -fno-split-dwarf-inlining
2470
2471Provide minimal debug info in the object/executable to facilitate online symbolication/stack traces in the absence of .dwo/.dwp files when using Split DWARF
2472
2473.. option:: -fsplit-lto-unit, -fno-split-lto-unit
2474
2475Enables splitting of the LTO unit
2476
2477.. option:: -fsplit-machine-functions, -fno-split-machine-functions
2478
2479Enable late function splitting using profile information (x86 ELF)
2480
2481.. option:: -fsplit-stack, -fno-split-stack
2482
2483Use segmented stack
2484
2485.. option:: -fstack-clash-protection, -fno-stack-clash-protection
2486
2487Enable stack clash protection
2488
2489.. option:: -fstack-protector, -fno-stack-protector
2490
2491Enable stack protectors for some functions vulnerable to stack smashing. This uses a loose heuristic which considers functions vulnerable if they contain a char (or 8bit integer) array or constant sized calls to alloca , which are of greater size than ssp-buffer-size (default: 8 bytes). All variable sized calls to alloca are considered vulnerable. A function with a stack protector has a guard value added to the stack frame that is checked on function exit. The guard value must be positioned in the stack frame such that a buffer overflow from a vulnerable variable will overwrite the guard value before overwriting the function's return address. The reference stack guard value is stored in a global variable.
2492
2493.. option:: -fstack-protector-all
2494
2495Enable stack protectors for all functions
2496
2497.. option:: -fstack-protector-strong
2498
2499Enable stack protectors for some functions vulnerable to stack smashing. Compared to -fstack-protector, this uses a stronger heuristic that includes functions containing arrays of any size (and any type), as well as any calls to alloca or the taking of an address from a local variable
2500
2501.. option:: -fstack-size-section, -fno-stack-size-section
2502
2503Emit section containing metadata on function stack sizes
2504
2505.. option:: -fstack-usage
2506
2507Emit .su file containing information on function stack sizes
2508
2509.. option:: -fstandalone-debug, -fno-limit-debug-info, -fno-standalone-debug
2510
2511Emit full debug info for all types used by the program
2512
2513.. option:: -fstrict-aliasing, -fno-strict-aliasing
2514
2515.. option:: -fstrict-enums, -fno-strict-enums
2516
2517Enable optimizations based on the strict definition of an enum's value range
2518
2519.. option:: -fstrict-float-cast-overflow, -fno-strict-float-cast-overflow
2520
2521Assume that overflowing float-to-int casts are undefined (default)
2522
2523.. option:: -fstrict-overflow, -fno-strict-overflow
2524
2525.. option:: -fstrict-return, -fno-strict-return
2526
2527.. option:: -fstrict-vtable-pointers, -fno-strict-vtable-pointers
2528
2529Enable optimizations based on the strict rules for overwriting polymorphic C++ objects
2530
2531.. option:: -fstruct-path-tbaa, -fno-struct-path-tbaa
2532
2533.. option:: -fswift-async-fp=<option>
2534
2535Control emission of Swift async extended frame info. <option> must be 'auto', 'always' or 'never'.
2536
2537.. option:: -fsymbol-partition=<arg>
2538
2539.. option:: -ftabstop=<arg>
2540
2541.. option:: -ftemplate-backtrace-limit=<arg>
2542
2543.. option:: -ftemplate-depth-<arg>
2544
2545.. option:: -ftemplate-depth=<arg>
2546
2547.. option:: -ftest-coverage, -fno-test-coverage
2548
2549.. option:: -fthin-link-bitcode=<arg>
2550
2551Write minimized bitcode to <file> for the ThinLTO thin link only
2552
2553.. option:: -fthinlto-index=<arg>
2554
2555Perform ThinLTO importing using provided function summary index
2556
2557.. option:: -fthreadsafe-statics, -fno-threadsafe-statics
2558
2559.. option:: -ftime-report
2560
2561.. program:: clang1
2562.. option:: -ftime-report=<arg>
2563.. program:: clang
2564
2565(For new pass manager) 'per-pass': one report for each pass; 'per-pass-run': one report for each pass invocation. <arg> must be 'per-pass' or 'per-pass-run'.
2566
2567.. option:: -ftime-trace
2568
2569
2570Turn on time profiler. Generates JSON file based on output filename. Results
2571can be analyzed with chrome://tracing or `Speedscope App
2572<https://www.speedscope.app>`_ for flamegraph visualization.
2573
2574.. option:: -ftime-trace-granularity=<arg>
2575
2576Minimum time granularity (in microseconds) traced by time profiler
2577
2578.. option:: -ftls-model=<arg>
2579
2580 <arg> must be 'global-dynamic', 'local-dynamic', 'initial-exec' or 'local-exec'.
2581
2582.. option:: -ftrap-function=<arg>
2583
2584Issue call to specified function rather than a trap instruction
2585
2586.. option:: -ftrapping-math, -fno-trapping-math
2587
2588.. option:: -ftrapv
2589
2590Trap on integer overflow
2591
2592.. option:: -ftrapv-handler <arg>
2593
2594.. program:: clang1
2595.. option:: -ftrapv-handler=<function name>
2596.. program:: clang
2597
2598Specify the function to be called on overflow
2599
2600.. option:: -ftrigraphs, -fno-trigraphs, -trigraphs, --trigraphs
2601
2602Process trigraph sequences
2603
2604.. option:: -ftrivial-auto-var-init-stop-after=<arg>
2605
2606Stop initializing trivial automatic stack variables after the specified number of instances
2607
2608.. option:: -ftrivial-auto-var-init=<arg>
2609
2610Initialize trivial automatic stack variables. Defaults to 'uninitialized'. <arg> must be 'uninitialized', 'zero' or 'pattern'.
2611
2612.. option:: -funique-basic-block-section-names, -fno-unique-basic-block-section-names
2613
2614Use unique names for basic block sections (ELF Only)
2615
2616.. option:: -funique-internal-linkage-names, -fno-unique-internal-linkage-names
2617
2618Uniqueify Internal Linkage Symbol Names by appending the MD5 hash of the module path
2619
2620.. option:: -funique-section-names, -fno-unique-section-names
2621
2622.. option:: -funroll-loops, -fno-unroll-loops
2623
2624Turn on loop unroller
2625
2626.. option:: -funsafe-math-optimizations, -fno-unsafe-math-optimizations
2627
2628.. option:: -funsigned-bitfields
2629
2630.. option:: -funsigned-char, -fno-unsigned-char, --unsigned-char
2631
2632.. option:: -funstable, -fno-unstable
2633
2634Enable unstable and experimental features
2635
2636.. option:: -funwind-tables, -fno-unwind-tables
2637
2638.. option:: -fuse-cxa-atexit, -fno-use-cxa-atexit
2639
2640.. option:: -fuse-init-array, -fno-use-init-array
2641
2642.. option:: -fstrict-flex-arrays=<arg>, -fno-strict-flex-arrays
2643
2644Control which arrays are considered as flexible arrays members. <arg>
2645can be 1 (array of size 0, 1 and undefined are considered), 2 (array of size 0
2646and undefined are considered) or 3 (only array of undefined size are considered).
2647
2648.. option:: -fuse-ld=<arg>
2649
2650.. option:: -fuse-line-directives, -fno-use-line-directives
2651
2652Use #line in preprocessed output
2653
2654.. option:: -fvalidate-ast-input-files-content
2655
2656Compute and store the hash of input files used to build an AST. Files with mismatching mtime's are considered valid if both contents is identical
2657
2658.. option:: -fveclib=<arg>
2659
2660Use the given vector functions library. <arg> must be 'Accelerate', 'libmvec', 'MASSV', 'SVML', 'Darwin_libsystem_m' or 'none'.
2661
2662.. option:: -fvectorize, -fno-vectorize, -ftree-vectorize
2663
2664Enable the loop vectorization passes
2665
2666.. option:: -fverbose-asm, -dA, -fno-verbose-asm
2667
2668Generate verbose assembly output
2669
2670.. option:: -fvirtual-function-elimination, -fno-virtual-function-elimination
2671
2672Enables dead virtual function elimination optimization. Requires -flto=full
2673
2674.. option:: -fvisibility-dllexport=<arg>
2675
2676The visibility for dllexport definitions \[-fvisibility-from-dllstorageclass\]. <arg> must be 'default', 'hidden', 'internal' or 'protected'.
2677
2678.. option:: -fvisibility-externs-dllimport=<arg>
2679
2680The visibility for dllimport external declarations \[-fvisibility-from-dllstorageclass\]. <arg> must be 'default', 'hidden', 'internal' or 'protected'.
2681
2682.. option:: -fvisibility-externs-nodllstorageclass=<arg>
2683
2684The visibility for external declarations without an explicit DLL dllstorageclass \[-fvisibility-from-dllstorageclass\]. <arg> must be 'default', 'hidden', 'internal' or 'protected'.
2685
2686.. option:: -fvisibility-from-dllstorageclass, -fno-visibility-from-dllstorageclass
2687
2688Set the visibility of symbols in the generated code from their DLL storage class
2689
2690.. option:: -fvisibility-global-new-delete-hidden
2691
2692Give global C++ operator new and delete declarations hidden visibility
2693
2694.. option:: -fvisibility-inlines-hidden, -fno-visibility-inlines-hidden
2695
2696Give inline C++ member functions hidden visibility by default
2697
2698.. option:: -fvisibility-inlines-hidden-static-local-var, -fno-visibility-inlines-hidden-static-local-var
2699
2700When -fvisibility-inlines-hidden is enabled, static variables in inline C++ member functions will also be given hidden visibility by default
2701
2702.. option:: -fvisibility-ms-compat
2703
2704Give global types 'default' visibility and global functions and variables 'hidden' visibility by default
2705
2706.. option:: -fvisibility-nodllstorageclass=<arg>
2707
2708The visibility for definitions without an explicit DLL export class \[-fvisibility-from-dllstorageclass\]. <arg> must be 'default', 'hidden', 'internal' or 'protected'.
2709
2710.. option:: -fvisibility=<arg>
2711
2712Set the default symbol visibility for all global declarations. <arg> must be 'hidden' or 'default'.
2713
2714.. option:: -fwasm-exceptions
2715
2716Use WebAssembly style exceptions
2717
2718.. option:: -fwhole-program-vtables, -fno-whole-program-vtables
2719
2720Enables whole-program vtable optimization. Requires -flto
2721
2722.. option:: -fwrapv, -fno-wrapv
2723
2724Treat signed integer overflow as two's complement
2725
2726.. option:: -fwritable-strings
2727
2728Store string literals as writable data
2729
2730.. option:: -fxl-pragma-pack, -fno-xl-pragma-pack
2731
2732Enable IBM XL #pragma pack handling
2733
2734.. option:: -fxray-always-emit-customevents, -fno-xray-always-emit-customevents
2735
2736Always emit \_\_xray\_customevent(...) calls even if the containing function is not always instrumented
2737
2738.. option:: -fxray-always-emit-typedevents, -fno-xray-always-emit-typedevents
2739
2740Always emit \_\_xray\_typedevent(...) calls even if the containing function is not always instrumented
2741
2742.. option:: -fxray-always-instrument=<arg>
2743
2744DEPRECATED: Filename defining the whitelist for imbuing the 'always instrument' XRay attribute.
2745
2746.. option:: -fxray-attr-list=<arg>
2747
2748Filename defining the list of functions/types for imbuing XRay attributes.
2749
2750.. option:: -fxray-function-groups=<arg>
2751
2752Only instrument 1 of N groups
2753
2754.. option:: -fxray-function-index, -fno-xray-function-index
2755
2756.. option:: -fxray-ignore-loops, -fno-xray-ignore-loops
2757
2758Don't instrument functions with loops unless they also meet the minimum function size
2759
2760.. option:: -fxray-instruction-threshold<arg>
2761
2762.. program:: clang1
2763.. option:: -fxray-instruction-threshold=<arg>
2764.. program:: clang
2765
2766Sets the minimum function size to instrument with XRay
2767
2768.. option:: -fxray-instrument, -fno-xray-instrument
2769
2770Generate XRay instrumentation sleds on function entry and exit
2771
2772.. option:: -fxray-instrumentation-bundle=<arg>
2773
2774Select which XRay instrumentation points to emit. Options: all, none, function-entry, function-exit, function, custom. Default is 'all'.  'function' includes both 'function-entry' and 'function-exit'.
2775
2776.. option:: -fxray-link-deps
2777
2778Tells clang to add the link dependencies for XRay.
2779
2780.. option:: -fxray-modes=<arg>
2781
2782List of modes to link in by default into XRay instrumented binaries.
2783
2784.. option:: -fxray-never-instrument=<arg>
2785
2786DEPRECATED: Filename defining the whitelist for imbuing the 'never instrument' XRay attribute.
2787
2788.. option:: -fxray-selected-function-group=<arg>
2789
2790When using -fxray-function-groups, select which group of functions to instrument. Valid range is 0 to fxray-function-groups - 1
2791
2792.. option:: -fzero-call-used-regs=<arg>
2793
2794Clear call-used registers upon function return (AArch64/x86 only). <arg> must be 'skip', 'used-gpr-arg', 'used-gpr', 'used-arg', 'used', 'all-gpr-arg', 'all-gpr', 'all-arg' or 'all'.
2795
2796.. option:: -fzero-initialized-in-bss, -fno-zero-initialized-in-bss
2797
2798.. option:: -fzvector, -fno-zvector, -mzvector
2799
2800Enable System z vector language extension
2801
2802.. option:: --gpu-bundle-output, --no-gpu-bundle-output
2803
2804Bundle output files of HIP device compilation
2805
2806.. option:: --offload-new-driver, --no-offload-new-driver
2807
2808Use the new driver for offloading compilation.
2809
2810.. option:: -pedantic, --pedantic, -no-pedantic, --no-pedantic
2811
2812Warn on language extensions
2813
2814.. option:: -pedantic-errors, --pedantic-errors
2815
2816OpenCL flags
2817------------
2818.. option:: -cl-denorms-are-zero
2819
2820OpenCL only. Allow denormals to be flushed to zero.
2821
2822.. option:: -cl-ext=<arg1>,<arg2>...
2823
2824OpenCL only. Enable or disable OpenCL extensions/optional features. The argument is a comma-separated sequence of one or more extension names, each prefixed by '+' or '-'.
2825
2826.. option:: -cl-fast-relaxed-math
2827
2828OpenCL only. Sets -cl-finite-math-only and -cl-unsafe-math-optimizations, and defines \_\_FAST\_RELAXED\_MATH\_\_.
2829
2830.. option:: -cl-finite-math-only
2831
2832OpenCL only. Allow floating-point optimizations that assume arguments and results are not NaNs or +-Inf.
2833
2834.. option:: -cl-fp32-correctly-rounded-divide-sqrt
2835
2836OpenCL only. Specify that single precision floating-point divide and sqrt used in the program source are correctly rounded.
2837
2838.. option:: -cl-kernel-arg-info
2839
2840OpenCL only. Generate kernel argument metadata.
2841
2842.. option:: -cl-mad-enable
2843
2844OpenCL only. Allow use of less precise MAD computations in the generated binary.
2845
2846.. option:: -cl-no-signed-zeros
2847
2848OpenCL only. Allow use of less precise no signed zeros computations in the generated binary.
2849
2850.. option:: -cl-no-stdinc
2851
2852OpenCL only. Disables all standard includes containing non-native compiler types and functions.
2853
2854.. option:: -cl-opt-disable
2855
2856OpenCL only. This option disables all optimizations. By default optimizations are enabled.
2857
2858.. option:: -cl-single-precision-constant
2859
2860OpenCL only. Treat double precision floating-point constant as single precision constant.
2861
2862.. option:: -cl-std=<arg>
2863
2864OpenCL language standard to compile for. <arg> must be 'cl', 'CL', 'cl1.0', 'CL1.0', 'cl1.1', 'CL1.1', 'cl1.2', 'CL1.2', 'cl2.0', 'CL2.0', 'cl3.0', 'CL3.0', 'clc++', 'CLC++', 'clc++1.0', 'CLC++1.0', 'clc++2021' or 'CLC++2021'.
2865
2866.. option:: -cl-strict-aliasing
2867
2868OpenCL only. This option is added for compatibility with OpenCL 1.0.
2869
2870.. option:: -cl-uniform-work-group-size
2871
2872OpenCL only. Defines that the global work-size be a multiple of the work-group size specified to clEnqueueNDRangeKernel
2873
2874.. option:: -cl-unsafe-math-optimizations
2875
2876OpenCL only. Allow unsafe floating-point optimizations.  Also implies -cl-no-signed-zeros and -cl-mad-enable.
2877
2878SYCL flags
2879----------
2880.. option:: -fsycl, -fno-sycl
2881
2882Enables SYCL kernels compilation for device
2883
2884.. option:: -sycl-std=<arg>
2885
2886SYCL language standard to compile for. <arg> must be '2020', '2017', '121', '1.2.1' or 'sycl-1.2.1'.
2887
2888Target-dependent compilation options
2889~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2890.. option:: -G<size>, -G=<arg>, -msmall-data-limit=<arg>, -msmall-data-threshold=<arg>
2891
2892Put objects of at most <size> bytes into small data section (MIPS / Hexagon)
2893
2894.. option:: -ffixed-x1
2895
2896Reserve the x1 register (AArch64/RISC-V only)
2897
2898.. option:: -ffixed-x10
2899
2900Reserve the x10 register (AArch64/RISC-V only)
2901
2902.. option:: -ffixed-x11
2903
2904Reserve the x11 register (AArch64/RISC-V only)
2905
2906.. option:: -ffixed-x12
2907
2908Reserve the x12 register (AArch64/RISC-V only)
2909
2910.. option:: -ffixed-x13
2911
2912Reserve the x13 register (AArch64/RISC-V only)
2913
2914.. option:: -ffixed-x14
2915
2916Reserve the x14 register (AArch64/RISC-V only)
2917
2918.. option:: -ffixed-x15
2919
2920Reserve the x15 register (AArch64/RISC-V only)
2921
2922.. option:: -ffixed-x16
2923
2924Reserve the x16 register (AArch64/RISC-V only)
2925
2926.. option:: -ffixed-x17
2927
2928Reserve the x17 register (AArch64/RISC-V only)
2929
2930.. option:: -ffixed-x18
2931
2932Reserve the x18 register (AArch64/RISC-V only)
2933
2934.. option:: -ffixed-x19
2935
2936Reserve the x19 register (AArch64/RISC-V only)
2937
2938.. option:: -ffixed-x2
2939
2940Reserve the x2 register (AArch64/RISC-V only)
2941
2942.. option:: -ffixed-x20
2943
2944Reserve the x20 register (AArch64/RISC-V only)
2945
2946.. option:: -ffixed-x21
2947
2948Reserve the x21 register (AArch64/RISC-V only)
2949
2950.. option:: -ffixed-x22
2951
2952Reserve the x22 register (AArch64/RISC-V only)
2953
2954.. option:: -ffixed-x23
2955
2956Reserve the x23 register (AArch64/RISC-V only)
2957
2958.. option:: -ffixed-x24
2959
2960Reserve the x24 register (AArch64/RISC-V only)
2961
2962.. option:: -ffixed-x25
2963
2964Reserve the x25 register (AArch64/RISC-V only)
2965
2966.. option:: -ffixed-x26
2967
2968Reserve the x26 register (AArch64/RISC-V only)
2969
2970.. option:: -ffixed-x27
2971
2972Reserve the x27 register (AArch64/RISC-V only)
2973
2974.. option:: -ffixed-x28
2975
2976Reserve the x28 register (AArch64/RISC-V only)
2977
2978.. option:: -ffixed-x29
2979
2980Reserve the x29 register (AArch64/RISC-V only)
2981
2982.. option:: -ffixed-x3
2983
2984Reserve the x3 register (AArch64/RISC-V only)
2985
2986.. option:: -ffixed-x30
2987
2988Reserve the x30 register (AArch64/RISC-V only)
2989
2990.. option:: -ffixed-x31
2991
2992Reserve the x31 register (AArch64/RISC-V only)
2993
2994.. option:: -ffixed-x4
2995
2996Reserve the x4 register (AArch64/RISC-V only)
2997
2998.. option:: -ffixed-x5
2999
3000Reserve the x5 register (AArch64/RISC-V only)
3001
3002.. option:: -ffixed-x6
3003
3004Reserve the x6 register (AArch64/RISC-V only)
3005
3006.. option:: -ffixed-x7
3007
3008Reserve the x7 register (AArch64/RISC-V only)
3009
3010.. option:: -ffixed-x8
3011
3012Reserve the x8 register (AArch64/RISC-V only)
3013
3014.. option:: -ffixed-x9
3015
3016Reserve the x9 register (AArch64/RISC-V only)
3017
3018.. option:: -ffuchsia-api-level=<arg>
3019
3020Set Fuchsia API level
3021
3022.. option:: -inline-asm=<arg>
3023
3024 <arg> must be 'att' or 'intel'.
3025
3026.. option:: -m16
3027
3028.. option:: -m32
3029
3030.. option:: -m64
3031
3032.. option:: -mabi=<arg>
3033
3034.. program:: clang1
3035.. option:: -mabi=vec-default
3036.. program:: clang
3037
3038Enable the default Altivec ABI on AIX (AIX only). Uses only volatile vector registers.
3039
3040.. program:: clang2
3041.. option:: -mabi=vec-extabi
3042.. program:: clang
3043
3044Enable the extended Altivec ABI on AIX (AIX only). Uses volatile and nonvolatile vector registers
3045
3046.. option:: -maix-struct-return
3047
3048Return all structs in memory (PPC32 only)
3049
3050.. option:: -malign-branch-boundary=<arg>
3051
3052Specify the boundary's size to align branches
3053
3054.. option:: -malign-branch=<arg1>,<arg2>...
3055
3056Specify types of branches to align
3057
3058.. option:: -malign-double
3059
3060Align doubles to two words in structs (x86 only)
3061
3062.. option:: -mamdgpu-ieee, -mno-amdgpu-ieee
3063
3064Sets the IEEE bit in the expected default floating point  mode register. Floating point opcodes that support exception flag gathering quiet and propagate signaling NaN inputs per IEEE 754-2008. This option changes the ABI. (AMDGPU only)
3065
3066.. option:: -march=<arg>
3067
3068.. option:: -masm=<arg>
3069
3070.. option:: -mbackchain, -mno-backchain
3071
3072Link stack frames through backchain on System Z
3073
3074.. option:: -mbranch-protection=<arg>
3075
3076Enforce targets of indirect branches and function returns
3077
3078.. option:: -mbranches-within-32B-boundaries
3079
3080Align selected branches (fused, jcc, jmp) within 32-byte boundary
3081
3082.. option:: -mcmodel=<arg>, -mcmodel=medany (equivalent to -mcmodel=medium), -mcmodel=medlow (equivalent to -mcmodel=small)
3083
3084.. option:: -mcode-object-v3, -mno-code-object-v3
3085
3086Legacy option to specify code object ABI V3 (AMDGPU only)
3087
3088.. option:: -mcode-object-version=<arg>
3089
3090Specify code object ABI version. Defaults to 4. (AMDGPU only). <arg> must be 'none', '2', '3', '4' or '5'.
3091
3092.. option:: -mconsole<arg>
3093
3094.. program:: clang1
3095.. option:: -mcpu=<arg>, -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), -mv66 (equivalent to -mcpu=hexagonv66), -mv67 (equivalent to -mcpu=hexagonv67), -mv67t (equivalent to -mcpu=hexagonv67t), -mv68 (equivalent to -mcpu=hexagonv68), -mv69 (equivalent to -mcpu=hexagonv69)
3096.. program:: clang
3097
3098.. option:: -mcrc, -mno-crc
3099
3100Allow use of CRC instructions (ARM/Mips only)
3101
3102.. option:: -mdefault-build-attributes<arg>, -mno-default-build-attributes<arg>
3103
3104.. option:: -mdefault-visibility-export-mapping=<arg>
3105
3106Mapping between default visibility and export. <arg> must be 'none', 'explicit' or 'all'.
3107
3108.. option:: -mdll<arg>
3109
3110.. option:: -mdouble=<n
3111
3112Force double to be <n> bits. <n must be '32' or '64'.
3113
3114.. option:: -mdynamic-no-pic<arg>
3115
3116.. option:: -meabi <arg>
3117
3118Set EABI type. Default depends on triple). <arg> must be 'default', '4', '5' or 'gnu'.
3119
3120.. option:: -menable-experimental-extensions
3121
3122Enable use of experimental RISC-V extensions.
3123
3124.. option:: -mfentry
3125
3126Insert calls to fentry at function entry (x86/SystemZ only)
3127
3128.. option:: -mfloat-abi=<arg>
3129
3130 <arg> must be 'soft', 'softfp' or 'hard'.
3131
3132.. option:: -mfpmath=<arg>
3133
3134.. option:: -mfpu=<arg>
3135
3136.. option:: -mgeneral-regs-only
3137
3138Generate code which only uses the general purpose registers (AArch64/x86 only)
3139
3140.. option:: -mglobal-merge, -mno-global-merge
3141
3142Enable merging of globals
3143
3144.. option:: -mhard-float
3145
3146.. option:: -mhwdiv=<arg>, --mhwdiv <arg>, --mhwdiv=<arg>
3147
3148.. option:: -mhwmult=<arg>
3149
3150.. option:: -miamcu, -mno-iamcu
3151
3152Use Intel MCU ABI
3153
3154.. option:: -mibt-seal
3155
3156Optimize fcf-protection=branch/full (requires LTO).
3157
3158.. option:: -mignore-xcoff-visibility
3159
3160Not emit the visibility attribute for asm in AIX OS or give all symbols 'unspecified' visibility in XCOFF object file
3161
3162.. option:: -mimplicit-float, -mno-implicit-float
3163
3164.. option:: -mimplicit-it=<arg>
3165
3166.. option:: -mincremental-linker-compatible, -mno-incremental-linker-compatible
3167
3168(integrated-as) Emit an object file which can be used with an incremental linker
3169
3170.. option:: -miphoneos-version-min=<arg>, -mios-version-min=<arg>
3171
3172.. option:: -mkernel
3173
3174.. option:: -mlong-calls, -mno-long-calls
3175
3176Generate branches with extended addressability, usually via indirect jumps.
3177
3178.. option:: -mlvi-cfi, -mno-lvi-cfi
3179
3180Enable only control-flow mitigations for Load Value Injection (LVI)
3181
3182.. option:: -mlvi-hardening, -mno-lvi-hardening
3183
3184Enable all mitigations for Load Value Injection (LVI)
3185
3186.. option:: -mmacosx-version-min=<arg>, -mmacos-version-min=<arg>
3187
3188Set Mac OS X deployment target
3189
3190.. option:: -mmcu=<arg>
3191
3192.. option:: -mms-bitfields, -mno-ms-bitfields
3193
3194Set the default structure layout to be compatible with the Microsoft compiler standard
3195
3196.. option:: -mnop-mcount
3197
3198Generate mcount/\_\_fentry\_\_ calls as nops. To activate they need to be patched in.
3199
3200.. option:: -momit-leaf-frame-pointer, -mno-omit-leaf-frame-pointer
3201
3202Omit frame pointer setup for leaf functions
3203
3204.. option:: -moslib=<arg>
3205
3206.. option:: -mpacked-stack, -mno-packed-stack
3207
3208Use packed stack layout (SystemZ only).
3209
3210.. option:: -mpad-max-prefix-size=<arg>
3211
3212Specify maximum number of prefixes to use for padding
3213
3214.. option:: -mprefer-vector-width=<arg>
3215
3216Specifies preferred vector width for auto-vectorization. Defaults to 'none' which allows target specific decisions.
3217
3218.. option:: -mqdsp6-compat
3219
3220Enable hexagon-qdsp6 backward compatibility
3221
3222.. option:: -mrecip
3223
3224.. program:: clang1
3225.. option:: -mrecip=<arg1>,<arg2>...
3226.. program:: clang
3227
3228.. option:: -mrecord-mcount
3229
3230Generate a \_\_mcount\_loc section entry for each \_\_fentry\_\_ call.
3231
3232.. option:: -mred-zone, -mno-red-zone
3233
3234.. option:: -mregparm=<arg>
3235
3236.. option:: -mrelax, -mno-relax
3237
3238Enable linker relaxation
3239
3240.. option:: -mrelax-all, -mno-relax-all
3241
3242(integrated-as) Relax all machine instructions
3243
3244.. option:: -mretpoline, -mno-retpoline
3245
3246.. option:: -mrtd, -mno-rtd
3247
3248Make StdCall calling convention the default
3249
3250.. option:: -mseses, -mno-seses
3251
3252Enable speculative execution side effect suppression (SESES). Includes LVI control flow integrity mitigations
3253
3254.. option:: -msign-return-address=<arg>
3255
3256Select return address signing scope. <arg> must be 'none', 'all' or 'non-leaf'.
3257
3258.. option:: -msim
3259
3260.. option:: -mskip-rax-setup, -mno-skip-rax-setup
3261
3262Skip setting up RAX register when passing variable arguments (x86 only)
3263
3264.. option:: -msoft-float, -mno-soft-float
3265
3266Use software floating point
3267
3268.. option:: -mspeculative-load-hardening, -mno-speculative-load-hardening
3269
3270.. option:: -mstack-alignment=<arg>
3271
3272Set the stack alignment
3273
3274.. option:: -mstack-arg-probe, -mno-stack-arg-probe
3275
3276Enable stack probes
3277
3278.. option:: -mstack-probe-size=<arg>
3279
3280Set the stack probe size
3281
3282.. option:: -mstack-protector-guard-offset=<arg>
3283
3284Use the given offset for addressing the stack-protector guard
3285
3286.. option:: -mstack-protector-guard-reg=<arg>
3287
3288Use the given reg for addressing the stack-protector guard
3289
3290.. option:: -mstack-protector-guard=<arg>
3291
3292Use the given guard (global, tls) for addressing the stack-protector guard
3293
3294.. option:: -mstackrealign, -mno-stackrealign
3295
3296Force realign the stack at entry to every function
3297
3298.. option:: -msvr4-struct-return
3299
3300Return small structs in registers (PPC32 only)
3301
3302.. option:: -mtargetos=<arg>
3303
3304Set the deployment target to be the specified OS and OS version
3305
3306.. option:: -mthread-model <arg>
3307
3308The thread model to use. Defaults to 'posix'). <arg> must be 'posix' or 'single'.
3309
3310.. option:: -mthreads<arg>
3311
3312.. option:: -mthumb, -mno-thumb
3313
3314.. option:: -mtls-direct-seg-refs, -mno-tls-direct-seg-refs
3315
3316Enable direct TLS access through segment registers (default)
3317
3318.. option:: -mtls-size=<arg>
3319
3320Specify bit size of immediate TLS offsets (AArch64 ELF only): 12 (for 4KB) \| 24 (for 16MB, default) \| 32 (for 4GB) \| 48 (for 256TB, needs -mcmodel=large)
3321
3322.. program:: clang1
3323.. option:: -mtune=<arg>
3324.. program:: clang
3325
3326Only supported on X86 and RISC-V. Otherwise accepted for compatibility with GCC.
3327
3328.. option:: -mtvos-version-min=<arg>, -mappletvos-version-min=<arg>
3329
3330.. option:: -municode<arg>
3331
3332.. option:: -munsafe-fp-atomics, -mno-unsafe-fp-atomics
3333
3334Enable unsafe floating point atomic instructions (AMDGPU only)
3335
3336.. option:: -mvx, -mno-vx
3337
3338.. option:: -mwarn-nonportable-cfstrings, -mno-warn-nonportable-cfstrings
3339
3340.. option:: -mwatchos-version-min=<arg>
3341
3342.. option:: -mwavefrontsize64, -mno-wavefrontsize64
3343
3344Specify wavefront size 64 mode (AMDGPU only)
3345
3346.. option:: -mwindows<arg>
3347
3348.. option:: -mx32
3349
3350AARCH64
3351-------
3352.. option:: -fcall-saved-x10
3353
3354Make the x10 register call-saved (AArch64 only)
3355
3356.. option:: -fcall-saved-x11
3357
3358Make the x11 register call-saved (AArch64 only)
3359
3360.. option:: -fcall-saved-x12
3361
3362Make the x12 register call-saved (AArch64 only)
3363
3364.. option:: -fcall-saved-x13
3365
3366Make the x13 register call-saved (AArch64 only)
3367
3368.. option:: -fcall-saved-x14
3369
3370Make the x14 register call-saved (AArch64 only)
3371
3372.. option:: -fcall-saved-x15
3373
3374Make the x15 register call-saved (AArch64 only)
3375
3376.. option:: -fcall-saved-x18
3377
3378Make the x18 register call-saved (AArch64 only)
3379
3380.. option:: -fcall-saved-x8
3381
3382Make the x8 register call-saved (AArch64 only)
3383
3384.. option:: -fcall-saved-x9
3385
3386Make the x9 register call-saved (AArch64 only)
3387
3388.. option:: -mfix-cortex-a53-835769, -mno-fix-cortex-a53-835769
3389
3390Workaround Cortex-A53 erratum 835769 (AArch64 only)
3391
3392.. option:: -mmark-bti-property
3393
3394Add .note.gnu.property with BTI to assembly files (AArch64 only)
3395
3396.. option:: -msve-vector-bits=<arg>
3397
3398Specify the size in bits of an SVE vector register. Defaults to the vector length agnostic value of "scalable". (AArch64 only)
3399
3400.. option:: -mvscale-max=<arg>
3401
3402Specify the vscale maximum. Defaults to the vector length agnostic value of "0". (AArch64 only)
3403
3404.. option:: -mvscale-min=<arg>
3405
3406Specify the vscale minimum. Defaults to "1". (AArch64 only)
3407
3408AMDGPU
3409------
3410.. option:: -mcumode, -mno-cumode
3411
3412Specify CU wavefront execution mode (AMDGPU only)
3413
3414.. option:: -mtgsplit, -mno-tgsplit
3415
3416Enable threadgroup split execution mode (AMDGPU only)
3417
3418ARM
3419---
3420.. option:: -faapcs-bitfield-load
3421
3422Follows the AAPCS standard that all volatile bit-field write generates at least one load. (ARM only).
3423
3424.. option:: -faapcs-bitfield-width, -fno-aapcs-bitfield-width
3425
3426Follow the AAPCS standard requirement stating that volatile bit-field width is dictated by the field container type. (ARM only).
3427
3428.. option:: -ffixed-r9
3429
3430Reserve the r9 register (ARM only)
3431
3432.. option:: -mcmse
3433
3434Allow use of CMSE (Armv8-M Security Extensions)
3435
3436.. option:: -mexecute-only, -mno-execute-only, -mpure-code
3437
3438Disallow generation of data access to code sections (ARM only)
3439
3440.. option:: -mfix-cmse-cve-2021-35465, -mno-fix-cmse-cve-2021-35465
3441
3442Work around VLLDM erratum CVE-2021-35465 (ARM only)
3443
3444.. option:: -mfix-cortex-a57-aes-1742098, -mfix-cortex-a72-aes-1655431, -mno-fix-cortex-a57-aes-1742098
3445
3446Work around Cortex-A57 Erratum 1742098 (ARM only)
3447
3448.. option:: -mno-bti-at-return-twice
3449
3450Do not add a BTI instruction after a setjmp or other return-twice construct (Arm/AArch64 only)
3451
3452.. option:: -mno-movt
3453
3454Disallow use of movt/movw pairs (ARM only)
3455
3456.. option:: -mno-neg-immediates
3457
3458Disallow converting instructions with negative immediates to their negation or inversion.
3459
3460.. option:: -mnocrc
3461
3462Disallow use of CRC instructions (ARM only)
3463
3464.. option:: -mrestrict-it, -mno-restrict-it
3465
3466Disallow generation of complex IT blocks.
3467
3468.. option:: -mtp=<arg>
3469
3470Thread pointer access method (AArch32/AArch64 only). <arg> must be 'soft', 'cp15', 'el0', 'el1', 'el2' or 'el3'.
3471
3472.. option:: -munaligned-access, -mno-unaligned-access
3473
3474Allow memory accesses to be unaligned (AArch32/AArch64 only)
3475
3476Hexagon
3477-------
3478.. option:: -mhvx-ieee-fp, -mno-hvx-ieee-fp
3479
3480Enable Hexagon HVX IEEE floating-point
3481
3482.. option:: -mieee-rnd-near
3483
3484.. option:: -mmemops, -mno-memops
3485
3486Enable generation of memop instructions
3487
3488.. option:: -mnvj, -mno-nvj
3489
3490Enable generation of new-value jumps
3491
3492.. option:: -mnvs, -mno-nvs
3493
3494Enable generation of new-value stores
3495
3496.. option:: -mpackets, -mno-packets
3497
3498Enable generation of instruction packets
3499
3500Hexagon
3501-------
3502.. option:: -mhvx, -mno-hvx
3503
3504Enable Hexagon Vector eXtensions
3505
3506.. option:: -mhvx-length=<arg>
3507
3508Set Hexagon Vector Length. <arg> must be '64B' or '128B'.
3509
3510.. option:: -mhvx-qfloat, -mno-hvx-qfloat
3511
3512Enable Hexagon HVX QFloat instructions
3513
3514.. program:: clang1
3515.. option:: -mhvx=<arg>
3516.. program:: clang
3517
3518Enable Hexagon Vector eXtensions
3519
3520M68k
3521----
3522.. option:: -ffixed-a0
3523
3524Reserve the a0 register (M68k only)
3525
3526.. option:: -ffixed-a1
3527
3528Reserve the a1 register (M68k only)
3529
3530.. option:: -ffixed-a2
3531
3532Reserve the a2 register (M68k only)
3533
3534.. option:: -ffixed-a3
3535
3536Reserve the a3 register (M68k only)
3537
3538.. option:: -ffixed-a4
3539
3540Reserve the a4 register (M68k only)
3541
3542.. option:: -ffixed-a5
3543
3544Reserve the a5 register (M68k only)
3545
3546.. option:: -ffixed-a6
3547
3548Reserve the a6 register (M68k only)
3549
3550.. option:: -ffixed-d0
3551
3552Reserve the d0 register (M68k only)
3553
3554.. option:: -ffixed-d1
3555
3556Reserve the d1 register (M68k only)
3557
3558.. option:: -ffixed-d2
3559
3560Reserve the d2 register (M68k only)
3561
3562.. option:: -ffixed-d3
3563
3564Reserve the d3 register (M68k only)
3565
3566.. option:: -ffixed-d4
3567
3568Reserve the d4 register (M68k only)
3569
3570.. option:: -ffixed-d5
3571
3572Reserve the d5 register (M68k only)
3573
3574.. option:: -ffixed-d6
3575
3576Reserve the d6 register (M68k only)
3577
3578.. option:: -ffixed-d7
3579
3580Reserve the d7 register (M68k only)
3581
3582.. option:: -m68000
3583
3584.. option:: -m68010
3585
3586.. option:: -m68020
3587
3588.. option:: -m68030
3589
3590.. option:: -m68040
3591
3592.. option:: -m68060
3593
3594MIPS
3595----
3596.. option:: -mabicalls, -mno-abicalls
3597
3598Enable SVR4-style position-independent code (Mips only)
3599
3600.. option:: -mabs=<arg>
3601
3602.. option:: -mcheck-zero-division, -mno-check-zero-division
3603
3604.. option:: -mcompact-branches=<arg>
3605
3606.. option:: -mdouble-float
3607
3608.. option:: -mdsp, -mno-dsp
3609
3610.. option:: -mdspr2, -mno-dspr2
3611
3612.. option:: -membedded-data, -mno-embedded-data
3613
3614Place constants in the .rodata section instead of the .sdata section even if they meet the -G <size> threshold (MIPS)
3615
3616.. option:: -mextern-sdata, -mno-extern-sdata
3617
3618Assume that externally defined data is in the small data if it meets the -G <size> threshold (MIPS)
3619
3620.. option:: -mfix4300
3621
3622.. option:: -mfp32
3623
3624Use 32-bit floating point registers (MIPS only)
3625
3626.. option:: -mfp64
3627
3628Use 64-bit floating point registers (MIPS only)
3629
3630.. option:: -mginv, -mno-ginv
3631
3632.. option:: -mgpopt, -mno-gpopt
3633
3634Use GP relative accesses for symbols known to be in a small data section (MIPS)
3635
3636.. option:: -mindirect-jump=<arg>
3637
3638Change indirect jump instructions to inhibit speculation
3639
3640.. option:: -mips16
3641
3642.. option:: -mldc1-sdc1, -mno-ldc1-sdc1
3643
3644.. option:: -mlocal-sdata, -mno-local-sdata
3645
3646Extend the -G behaviour to object local data (MIPS)
3647
3648.. option:: -mmadd4, -mno-madd4
3649
3650Enable the generation of 4-operand madd.s, madd.d and related instructions.
3651
3652.. option:: -mmicromips, -mno-micromips
3653
3654.. option:: -mmsa, -mno-msa
3655
3656Enable MSA ASE (MIPS only)
3657
3658.. option:: -mmt, -mno-mt
3659
3660Enable MT ASE (MIPS only)
3661
3662.. option:: -mnan=<arg>
3663
3664.. option:: -mno-mips16
3665
3666.. option:: -msingle-float
3667
3668.. option:: -mvirt, -mno-virt
3669
3670.. option:: -mxgot, -mno-xgot
3671
3672PowerPC
3673-------
3674.. option:: -maltivec, -mno-altivec
3675
3676.. option:: -mcmpb, -mno-cmpb
3677
3678.. option:: -mcrbits, -mno-crbits
3679
3680.. option:: -mcrypto, -mno-crypto
3681
3682.. option:: -mdirect-move, -mno-direct-move
3683
3684.. option:: -mefpu2
3685
3686.. option:: -mfloat128, -mno-float128
3687
3688.. option:: -mfprnd, -mno-fprnd
3689
3690.. option:: -mhtm, -mno-htm
3691
3692.. option:: -minvariant-function-descriptors, -mno-invariant-function-descriptors
3693
3694.. option:: -misel, -mno-isel
3695
3696.. option:: -mlongcall, -mno-longcall
3697
3698.. option:: -mmfocrf, -mmfcrf, -mno-mfocrf
3699
3700.. option:: -mmma, -mno-mma
3701
3702.. option:: -mpaired-vector-memops, -mno-paired-vector-memops
3703
3704.. option:: -mpcrel, -mno-pcrel
3705
3706.. option:: -mpopcntd, -mno-popcntd
3707
3708.. option:: -mpower10-vector, -mno-power10-vector
3709
3710.. option:: -mpower8-vector, -mno-power8-vector
3711
3712.. option:: -mpower9-vector, -mno-power9-vector
3713
3714.. option:: -mprefixed, -mno-prefixed
3715
3716.. option:: -mprivileged
3717
3718.. option:: -mrop-protect
3719
3720.. option:: -msecure-plt
3721
3722.. option:: -mspe, -mno-spe
3723
3724.. option:: -mvsx, -mno-vsx
3725
3726WebAssembly
3727-----------
3728.. option:: -matomics, -mno-atomics
3729
3730.. option:: -mbulk-memory, -mno-bulk-memory
3731
3732.. option:: -mexception-handling, -mno-exception-handling
3733
3734.. option:: -mextended-const, -mno-extended-const
3735
3736.. option:: -mmultivalue, -mno-multivalue
3737
3738.. option:: -mmutable-globals, -mno-mutable-globals
3739
3740.. option:: -mnontrapping-fptoint, -mno-nontrapping-fptoint
3741
3742.. option:: -mreference-types, -mno-reference-types
3743
3744.. option:: -mrelaxed-simd, -mno-relaxed-simd
3745
3746.. option:: -msign-ext, -mno-sign-ext
3747
3748.. option:: -msimd128, -mno-simd128
3749
3750.. option:: -mtail-call, -mno-tail-call
3751
3752WebAssembly Driver
3753------------------
3754.. option:: -mexec-model=<arg>
3755
3756Execution model (WebAssembly only). <arg> must be 'command' or 'reactor'.
3757
3758X86
3759---
3760.. option:: -m3dnow, -mno-3dnow
3761
3762.. option:: -m3dnowa, -mno-3dnowa
3763
3764.. option:: -madx, -mno-adx
3765
3766.. option:: -maes, -mno-aes
3767
3768.. option:: -mamx-bf16, -mno-amx-bf16
3769
3770.. option:: -mamx-int8, -mno-amx-int8
3771
3772.. option:: -mamx-tile, -mno-amx-tile
3773
3774.. option:: -mavx, -mno-avx
3775
3776.. option:: -mavx2, -mno-avx2
3777
3778.. option:: -mavx512bf16, -mno-avx512bf16
3779
3780.. option:: -mavx512bitalg, -mno-avx512bitalg
3781
3782.. option:: -mavx512bw, -mno-avx512bw
3783
3784.. option:: -mavx512cd, -mno-avx512cd
3785
3786.. option:: -mavx512dq, -mno-avx512dq
3787
3788.. option:: -mavx512er, -mno-avx512er
3789
3790.. option:: -mavx512f, -mno-avx512f
3791
3792.. option:: -mavx512fp16, -mno-avx512fp16
3793
3794.. option:: -mavx512ifma, -mno-avx512ifma
3795
3796.. option:: -mavx512pf, -mno-avx512pf
3797
3798.. option:: -mavx512vbmi, -mno-avx512vbmi
3799
3800.. option:: -mavx512vbmi2, -mno-avx512vbmi2
3801
3802.. option:: -mavx512vl, -mno-avx512vl
3803
3804.. option:: -mavx512vnni, -mno-avx512vnni
3805
3806.. option:: -mavx512vp2intersect, -mno-avx512vp2intersect
3807
3808.. option:: -mavx512vpopcntdq, -mno-avx512vpopcntdq
3809
3810.. option:: -mavxvnni, -mno-avxvnni
3811
3812.. option:: -mbmi, -mno-bmi
3813
3814.. option:: -mbmi2, -mno-bmi2
3815
3816.. option:: -mcldemote, -mno-cldemote
3817
3818.. option:: -mclflushopt, -mno-clflushopt
3819
3820.. option:: -mclwb, -mno-clwb
3821
3822.. option:: -mclzero, -mno-clzero
3823
3824.. option:: -mcrc32, -mno-crc32
3825
3826.. option:: -mcx16, -mno-cx16
3827
3828.. option:: -menqcmd, -mno-enqcmd
3829
3830.. option:: -mf16c, -mno-f16c
3831
3832.. option:: -mfma, -mno-fma
3833
3834.. option:: -mfma4, -mno-fma4
3835
3836.. option:: -mfsgsbase, -mno-fsgsbase
3837
3838.. option:: -mfxsr, -mno-fxsr
3839
3840.. option:: -mgfni, -mno-gfni
3841
3842.. option:: -mhreset, -mno-hreset
3843
3844.. option:: -minvpcid, -mno-invpcid
3845
3846.. option:: -mkl, -mno-kl
3847
3848.. option:: -mlwp, -mno-lwp
3849
3850.. option:: -mlzcnt, -mno-lzcnt
3851
3852.. option:: -mmmx, -mno-mmx
3853
3854.. option:: -mmovbe, -mno-movbe
3855
3856.. option:: -mmovdir64b, -mno-movdir64b
3857
3858.. option:: -mmovdiri, -mno-movdiri
3859
3860.. option:: -mmwaitx, -mno-mwaitx
3861
3862.. option:: -mpclmul, -mno-pclmul
3863
3864.. option:: -mpconfig, -mno-pconfig
3865
3866.. option:: -mpku, -mno-pku
3867
3868.. option:: -mpopcnt, -mno-popcnt
3869
3870.. option:: -mprefetchwt1, -mno-prefetchwt1
3871
3872.. option:: -mprfchw, -mno-prfchw
3873
3874.. option:: -mptwrite, -mno-ptwrite
3875
3876.. option:: -mrdpid, -mno-rdpid
3877
3878.. option:: -mrdrnd, -mno-rdrnd
3879
3880.. option:: -mrdseed, -mno-rdseed
3881
3882.. option:: -mretpoline-external-thunk, -mno-retpoline-external-thunk
3883
3884.. option:: -mrtm, -mno-rtm
3885
3886.. option:: -msahf, -mno-sahf
3887
3888.. option:: -mserialize, -mno-serialize
3889
3890.. option:: -msgx, -mno-sgx
3891
3892.. option:: -msha, -mno-sha
3893
3894.. option:: -mshstk, -mno-shstk
3895
3896.. option:: -msse, -mno-sse
3897
3898.. option:: -msse2, -mno-sse2
3899
3900.. option:: -msse3, -mno-sse3
3901
3902.. option:: -msse4.1, -mno-sse4.1
3903
3904.. program:: clang1
3905.. option:: -msse4.2, -mno-sse4.2, -msse4
3906.. program:: clang
3907
3908.. option:: -msse4a, -mno-sse4a
3909
3910.. option:: -mssse3, -mno-ssse3
3911
3912.. option:: -mtbm, -mno-tbm
3913
3914.. option:: -mtsxldtrk, -mno-tsxldtrk
3915
3916.. option:: -muintr, -mno-uintr
3917
3918.. option:: -mvaes, -mno-vaes
3919
3920.. option:: -mvpclmulqdq, -mno-vpclmulqdq
3921
3922.. option:: -mvzeroupper, -mno-vzeroupper
3923
3924.. option:: -mwaitpkg, -mno-waitpkg
3925
3926.. option:: -mwbnoinvd, -mno-wbnoinvd
3927
3928.. option:: -mwidekl, -mno-widekl
3929
3930.. option:: -mx87, -m80387, -mno-x87
3931
3932.. option:: -mxop, -mno-xop
3933
3934.. option:: -mxsave, -mno-xsave
3935
3936.. option:: -mxsavec, -mno-xsavec
3937
3938.. option:: -mxsaveopt, -mno-xsaveopt
3939
3940.. option:: -mxsaves, -mno-xsaves
3941
3942RISCV
3943-----
3944.. option:: -msave-restore, -mno-save-restore
3945
3946Enable using library calls for save and restore
3947
3948Long double flags
3949-----------------
3950Selects the long double implementation
3951
3952.. option:: -mlong-double-128
3953
3954Force long double to be 128 bits
3955
3956.. option:: -mlong-double-64
3957
3958Force long double to be 64 bits
3959
3960.. option:: -mlong-double-80
3961
3962Force long double to be 80 bits, padded to 128 bits for storage
3963
3964Optimization level
3965~~~~~~~~~~~~~~~~~~
3966
3967Flags controlling how much optimization should be performed.
3968
3969.. option:: -O<arg>, -O (equivalent to -O1), --optimize, --optimize=<arg>
3970
3971.. option:: -Ofast<arg>
3972
3973Debug information generation
3974~~~~~~~~~~~~~~~~~~~~~~~~~~~~
3975
3976Flags controlling how much and what kind of debug information should be
3977generated.
3978
3979Kind and level of debug information
3980-----------------------------------
3981.. option:: -g, --debug, --debug=<arg>
3982
3983Generate source-level debug information
3984
3985.. option:: -gdwarf
3986
3987Generate source-level debug information with the default dwarf version
3988
3989.. option:: -gdwarf-2
3990
3991Generate source-level debug information with dwarf version 2
3992
3993.. option:: -gdwarf-3
3994
3995Generate source-level debug information with dwarf version 3
3996
3997.. option:: -gdwarf-4
3998
3999Generate source-level debug information with dwarf version 4
4000
4001.. option:: -gdwarf-5
4002
4003Generate source-level debug information with dwarf version 5
4004
4005.. option:: -gdwarf32
4006
4007Enables DWARF32 format for ELF binaries, if debug information emission is enabled.
4008
4009.. option:: -gdwarf64
4010
4011Enables DWARF64 format for ELF binaries, if debug information emission is enabled.
4012
4013.. option:: -gfull
4014
4015.. option:: -ginline-line-tables, -gno-inline-line-tables
4016
4017.. option:: -gused
4018
4019Debug level
4020___________
4021.. option:: -g0
4022
4023.. option:: -g2
4024
4025.. option:: -g3
4026
4027.. option:: -ggdb0
4028
4029.. option:: -ggdb1
4030
4031.. option:: -ggdb2
4032
4033.. option:: -ggdb3
4034
4035.. option:: -gline-directives-only
4036
4037Emit debug line info directives only
4038
4039.. option:: -gline-tables-only, -g1, -gmlt
4040
4041Emit debug line number tables only
4042
4043.. option:: -gmodules
4044
4045Generate debug info with external references to clang modules or precompiled headers
4046
4047Debugger to tune debug information for
4048______________________________________
4049.. option:: -gdbx
4050
4051.. option:: -ggdb
4052
4053.. option:: -glldb
4054
4055.. option:: -gsce
4056
4057Debug information flags
4058-----------------------
4059.. option:: -gcolumn-info, -gno-column-info
4060
4061.. option:: -gdwarf-aranges
4062
4063.. option:: -gembed-source, -gno-embed-source
4064
4065Embed source text in DWARF debug sections
4066
4067.. option:: -ggnu-pubnames, -gno-gnu-pubnames
4068
4069.. option:: -gpubnames, -gno-pubnames
4070
4071.. option:: -grecord-command-line, -gno-record-command-line, -grecord-gcc-switches
4072
4073.. option:: -gsimple-template-names, -gno-simple-template-names
4074
4075.. option:: -gsplit-dwarf, -gno-split-dwarf
4076
4077.. program:: clang1
4078.. option:: -gsplit-dwarf=<arg>
4079.. program:: clang
4080
4081Set DWARF fission mode. <arg> must be 'split' or 'single'.
4082
4083.. option:: -gstrict-dwarf, -gno-strict-dwarf
4084
4085.. option:: -gz=<arg>, -gz (equivalent to -gz=zlib)
4086
4087DWARF debug sections compression type
4088
4089Static analyzer flags
4090=====================
4091
4092Flags controlling the behavior of the Clang Static Analyzer.
4093
4094.. option:: -Xanalyzer <arg>
4095
4096Pass <arg> to the static analyzer
4097
4098Fortran compilation flags
4099=========================
4100
4101Flags that will be passed onto the ``gfortran`` compiler when Clang is given
4102a Fortran input.
4103
4104.. option:: -A<arg>, --assert <arg>, --assert=<arg>
4105
4106.. option:: -A-<arg>
4107
4108.. option:: -faggressive-function-elimination, -fno-aggressive-function-elimination
4109
4110.. option:: -falign-commons, -fno-align-commons
4111
4112.. option:: -fall-intrinsics, -fno-all-intrinsics
4113
4114.. option:: -fbacktrace, -fno-backtrace
4115
4116.. option:: -fblas-matmul-limit=<arg>
4117
4118.. option:: -fbounds-check, -fno-bounds-check
4119
4120.. option:: -fcheck-array-temporaries, -fno-check-array-temporaries
4121
4122.. option:: -fcheck=<arg>
4123
4124.. option:: -fcoarray=<arg>
4125
4126.. option:: -fconvert=<arg>
4127
4128.. option:: -fcray-pointer, -fno-cray-pointer
4129
4130.. option:: -fd-lines-as-code, -fno-d-lines-as-code
4131
4132.. option:: -fd-lines-as-comments, -fno-d-lines-as-comments
4133
4134.. option:: -fdollar-ok, -fno-dollar-ok
4135
4136.. option:: -fdump-fortran-optimized, -fno-dump-fortran-optimized
4137
4138.. option:: -fdump-fortran-original, -fno-dump-fortran-original
4139
4140.. option:: -fdump-parse-tree, -fno-dump-parse-tree
4141
4142.. option:: -fexternal-blas, -fno-external-blas
4143
4144.. option:: -ff2c, -fno-f2c
4145
4146.. option:: -ffpe-trap=<arg>
4147
4148.. option:: -ffree-line-length-<arg>
4149
4150.. option:: -ffrontend-optimize, -fno-frontend-optimize
4151
4152.. option:: -finit-character=<arg>
4153
4154.. option:: -finit-integer=<arg>
4155
4156.. option:: -finit-local-zero, -fno-init-local-zero
4157
4158.. option:: -finit-logical=<arg>
4159
4160.. option:: -finit-real=<arg>
4161
4162.. option:: -finteger-4-integer-8, -fno-integer-4-integer-8
4163
4164.. option:: -fmax-array-constructor=<arg>
4165
4166.. option:: -fmax-errors=<arg>
4167
4168.. option:: -fmax-identifier-length, -fno-max-identifier-length
4169
4170.. option:: -fmax-stack-var-size=<arg>
4171
4172.. option:: -fmax-subrecord-length=<arg>
4173
4174.. option:: -fmodule-private, -fno-module-private
4175
4176.. option:: -fpack-derived, -fno-pack-derived
4177
4178.. option:: -frange-check, -fno-range-check
4179
4180.. option:: -freal-4-real-10, -fno-real-4-real-10
4181
4182.. option:: -freal-4-real-16, -fno-real-4-real-16
4183
4184.. option:: -freal-4-real-8, -fno-real-4-real-8
4185
4186.. option:: -freal-8-real-10, -fno-real-8-real-10
4187
4188.. option:: -freal-8-real-16, -fno-real-8-real-16
4189
4190.. option:: -freal-8-real-4, -fno-real-8-real-4
4191
4192.. option:: -frealloc-lhs, -fno-realloc-lhs
4193
4194.. option:: -frecord-marker=<arg>
4195
4196.. option:: -frecursive, -fno-recursive
4197
4198.. option:: -frepack-arrays, -fno-repack-arrays
4199
4200.. option:: -fsecond-underscore, -fno-second-underscore
4201
4202.. option:: -fsign-zero, -fno-sign-zero
4203
4204.. option:: -fstack-arrays, -fno-stack-arrays
4205
4206.. option:: -funderscoring, -fno-underscoring
4207
4208.. option:: -fwhole-file, -fno-whole-file
4209
4210.. option:: -imultilib <arg>
4211
4212.. option:: -static-libgfortran
4213
4214Linker flags
4215============
4216Flags that are passed on to the linker
4217
4218.. option:: -L<dir>, --library-directory <arg>, --library-directory=<arg>
4219
4220Add directory to library search path
4221
4222.. option:: -Mach
4223
4224.. option:: -T<script>
4225
4226Specify <script> as linker script
4227
4228.. option:: -Tbss<addr>
4229
4230Set starting address of BSS to <addr>
4231
4232.. option:: -Tdata<addr>
4233
4234Set starting address of DATA to <addr>
4235
4236.. option:: -Ttext<addr>
4237
4238Set starting address of TEXT to <addr>
4239
4240.. option:: -Wl,<arg>,<arg2>...
4241
4242Pass the comma separated arguments in <arg> to the linker
4243
4244.. option:: -X
4245
4246.. option:: -Xlinker <arg>, --for-linker <arg>, --for-linker=<arg>
4247
4248Pass <arg> to the linker
4249
4250.. option:: -Xoffload-linker<triple> <arg>
4251
4252Pass <arg> to the offload linkers or the ones idenfied by -<triple>
4253
4254.. program:: clang1
4255.. option:: -Z
4256.. program:: clang
4257
4258.. option:: -b<arg>
4259
4260Pass -b <arg> to the linker on AIX (only).
4261
4262.. option:: -coverage, --coverage
4263
4264.. option:: -e<arg>, --entry
4265
4266.. option:: -filelist <arg>
4267
4268.. option:: --hip-device-lib=<arg>
4269
4270HIP device library
4271
4272.. option:: --hipspv-pass-plugin=<dsopath>
4273
4274path to a pass plugin for HIP to SPIR-V passes.
4275
4276.. option:: -l<arg>
4277
4278.. option:: --ld-path=<arg>
4279
4280.. option:: -nostartfiles
4281
4282.. program:: clang1
4283.. option:: -nostdlib, --no-standard-libraries
4284.. program:: clang
4285
4286.. option:: --offload-link
4287
4288Use the new offloading linker to perform the link job.
4289
4290.. option:: -pie
4291
4292.. option:: -r
4293
4294.. option:: -rdynamic
4295
4296.. option:: --rocm-device-lib-path=<arg>, --hip-device-lib-path=<arg>
4297
4298ROCm device library path. Alternative to rocm-path.
4299
4300.. option:: -rpath <arg>
4301
4302.. option:: -s
4303
4304.. option:: -shared, --shared
4305
4306.. option:: -specs=<arg>, --specs=<arg>
4307
4308.. option:: -static, --static
4309
4310.. option:: -static-pie
4311
4312.. option:: -t
4313
4314.. option:: -u<arg>, --force-link <arg>, --force-link=<arg>
4315
4316.. option:: -undef
4317
4318undef all system defines
4319
4320.. option:: -undefined<arg>, --no-undefined
4321
4322.. option:: -z <arg>
4323
4324Pass -z <arg> to the linker
4325
4326<clang-dxc options>
4327===================
4328dxc compatibility options
4329
4330.. program:: clang3
4331.. option:: /T<profile>, -T<profile>
4332.. program:: clang
4333
4334Set target profile. <profile> must be 'ps_6_0', ' ps_6_1', ' ps_6_2', ' ps_6_3', ' ps_6_4', ' ps_6_5', ' ps_6_6', ' ps_6_7', 'vs_6_0', ' vs_6_1', ' vs_6_2', ' vs_6_3', ' vs_6_4', ' vs_6_5', ' vs_6_6', ' vs_6_7', 'gs_6_0', ' gs_6_1', ' gs_6_2', ' gs_6_3', ' gs_6_4', ' gs_6_5', ' gs_6_6', ' gs_6_7', 'hs_6_0', ' hs_6_1', ' hs_6_2', ' hs_6_3', ' hs_6_4', ' hs_6_5', ' hs_6_6', ' hs_6_7', 'ds_6_0', ' ds_6_1', ' ds_6_2', ' ds_6_3', ' ds_6_4', ' ds_6_5', ' ds_6_6', ' ds_6_7', 'cs_6_0', ' cs_6_1', ' cs_6_2', ' cs_6_3', ' cs_6_4', ' cs_6_5', ' cs_6_6', ' cs_6_7', 'lib_6_3', ' lib_6_4', ' lib_6_5', ' lib_6_6', ' lib_6_7', ' lib_6_x', 'ms_6_5', ' ms_6_6', ' ms_6_7', 'as_6_5', ' as_6_6' or ' as_6_7'.
4335
4336.. program:: clang4
4337.. option:: /emit-pristine-llvm, -emit-pristine-llvm, /fcgl, -fcgl
4338.. program:: clang
4339
4340Emit pristine LLVM IR from the frontend by not running any LLVM passes at all.Same as -S + -emit-llvm + -disable-llvm-passes.
4341
4342.. program:: clang5
4343.. option:: /hlsl-no-stdinc, -hlsl-no-stdinc
4344.. program:: clang
4345
4346HLSL only. Disables all standard includes containing non-native compiler types and functions.
4347
4348