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<dir>, --prefix <arg>, --prefix=<arg> 22 23Add <dir> to search path for binaries and object files used implicitly 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.. option:: -Xcuda-fatbinary <arg> 60 61Pass <arg> to fatbinary invocation 62 63.. option:: -Xcuda-ptxas <arg> 64 65Pass <arg> to the ptxas assembler 66 67.. option:: -Xopenmp-target <arg> 68 69Pass <arg> to the target offloading toolchain. 70 71.. program:: clang1 72.. option:: -Xopenmp-target=<triple> <arg> 73.. program:: clang 74 75Pass <arg> to the target offloading toolchain identified by <triple>. 76 77.. option:: -Z<arg> 78 79.. option:: -a<arg>, --profile-blocks 80 81.. option:: -all\_load 82 83.. option:: -allowable\_client <arg> 84 85.. option:: --analyze 86 87Run the static analyzer 88 89.. option:: --analyzer-no-default-checks 90 91.. option:: --analyzer-output<arg> 92 93Static analyzer report output format (html\|plist\|plist-multi-file\|plist-html\|text). 94 95.. option:: -ansi, --ansi 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:: -cfguard 126 127Emit tables and checks for Windows Control Flow Guard. 128 129.. option:: -cfguard-no-checks 130 131Emit tables required for Windows Control Flow Guard without checks. 132 133.. option:: -client\_name<arg> 134 135.. option:: -compatibility\_version<arg> 136 137.. option:: --config <arg> 138 139Specifies configuration file 140 141.. option:: --constant-cfstrings 142 143.. option:: -coverage, --coverage 144 145.. option:: --cuda-compile-host-device 146 147Compile CUDA code for both host and device (default). Has no effect on non-CUDA compilations. 148 149.. option:: --cuda-device-only 150 151Compile CUDA code for device only 152 153.. option:: --cuda-gpu-arch=<arg>, --no-cuda-gpu-arch=<arg> 154 155CUDA GPU architecture (e.g. sm\_35). May be specified more than once. 156 157.. option:: --cuda-host-only 158 159Compile CUDA code for host only. Has no effect on non-CUDA compilations. 160 161.. option:: --cuda-include-ptx=<arg>, --no-cuda-include-ptx=<arg> 162 163Include PTX for the following GPU architecture (e.g. sm\_35) or 'all'. May be specified more than once. 164 165.. option:: --cuda-noopt-device-debug, --no-cuda-noopt-device-debug 166 167Enable device-side debug info generation. Disables ptxas optimizations. 168 169.. option:: -current\_version<arg> 170 171.. option:: -dead\_strip 172 173.. option:: -dependency-dot <arg> 174 175Filename to write DOT-formatted header dependencies to 176 177.. option:: -dependency-file <arg> 178 179Filename (or -) to write dependency output to 180 181.. option:: -dumpmachine 182 183.. option:: -dumpversion 184 185.. option:: --dyld-prefix=<arg>, --dyld-prefix <arg> 186 187.. option:: -dylib\_file <arg> 188 189.. option:: -dylinker 190 191.. program:: clang1 192.. option:: -dylinker\_install\_name<arg> 193.. program:: clang 194 195.. option:: -dynamic 196 197.. option:: -dynamiclib 198 199.. option:: -emit-ast 200 201Emit Clang AST files for source inputs 202 203.. option:: -exported\_symbols\_list <arg> 204 205.. option:: -faligned-new=<arg> 206 207.. option:: -fcuda-approx-transcendentals, -fno-cuda-approx-transcendentals 208 209Use approximate transcendental functions 210 211.. option:: -fcuda-flush-denormals-to-zero, -fno-cuda-flush-denormals-to-zero 212 213Flush denormal floating point values to zero in CUDA device mode. 214 215.. option:: -fcuda-rdc, -fno-cuda-rdc 216 217Generate relocatable device code, also known as separate compilation mode. 218 219.. option:: -fcuda-short-ptr, -fno-cuda-short-ptr 220 221Use 32-bit pointers for accessing const/local/shared address spaces. 222 223.. option:: -ffixed-r19 224 225Reserve register r19 (Hexagon only) 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:: -framework <arg> 246 247.. option:: -frtlib-add-rpath, -fno-rtlib-add-rpath 248 249Add -rpath with architecture-specific resource directory to the linker flags 250 251.. option:: --gcc-toolchain=<arg>, -gcc-toolchain <arg> 252 253Use the gcc toolchain at the given directory 254 255.. option:: -gcodeview 256 257Generate CodeView debug information 258 259.. option:: -headerpad\_max\_install\_names<arg> 260 261.. option:: -help, --help 262 263Display available options 264 265.. option:: --help-hidden 266 267Display help for hidden options 268 269.. option:: --hip-link 270 271Link clang-offload-bundler bundles for HIP 272 273.. option:: -image\_base <arg> 274 275.. option:: -index-header-map 276 277Make the next included directory (-I or -F) an indexer header map 278 279.. option:: -init <arg> 280 281.. option:: -install\_name <arg> 282 283.. option:: -keep\_private\_externs 284 285.. option:: -lazy\_framework <arg> 286 287.. program:: clang1 288.. option:: -lazy\_library <arg> 289.. program:: clang 290 291.. option:: -mbig-endian, -EB 292 293.. option:: --migrate 294 295Run the migrator 296 297.. option:: -mios-simulator-version-min=<arg>, -miphonesimulator-version-min=<arg> 298 299.. option:: -mlinker-version=<arg> 300 301.. option:: -mlittle-endian, -EL 302 303.. option:: -mllvm <arg> 304 305Additional arguments to forward to LLVM's option processing 306 307.. option:: -module-dependency-dir <arg> 308 309Directory to dump module dependencies to 310 311.. option:: -mtvos-simulator-version-min=<arg>, -mappletvsimulator-version-min=<arg> 312 313.. option:: -multi\_module 314 315.. option:: -multiply\_defined <arg> 316 317.. program:: clang1 318.. option:: -multiply\_defined\_unused <arg> 319.. program:: clang 320 321.. option:: -mwatchos-simulator-version-min=<arg>, -mwatchsimulator-version-min=<arg> 322 323.. option:: --no-cuda-version-check 324 325Don't error out if the detected version of the CUDA install is too low for the requested CUDA gpu architecture. 326 327.. option:: -no-integrated-cpp, --no-integrated-cpp 328 329.. option:: -no\_dead\_strip\_inits\_and\_terms 330 331.. option:: -nobuiltininc 332 333Disable builtin #include directories 334 335.. option:: -nocudainc 336 337.. option:: -nocudalib 338 339.. option:: -nodefaultlibs 340 341.. option:: -nofixprebinding 342 343.. option:: -nolibc 344 345.. option:: -nomultidefs 346 347.. option:: -nopie, -no-pie 348 349.. option:: -noprebind 350 351.. option:: -noprofilelib 352 353.. option:: -noseglinkedit 354 355.. option:: -nostartfiles 356 357.. option:: -nostdinc, --no-standard-includes 358 359.. program:: clang1 360.. option:: -nostdinc++ 361.. program:: clang 362 363Disable standard #include directories for the C++ standard library 364 365.. option:: -nostdlib, --no-standard-libraries 366 367.. program:: clang1 368.. option:: -nostdlib++ 369.. program:: clang 370 371.. option:: -nostdlibinc 372 373.. option:: -o<file>, --output <arg>, --output=<arg> 374 375Write output to <file> 376 377.. option:: -objcmt-atomic-property 378 379Make migration to 'atomic' properties 380 381.. option:: -objcmt-migrate-all 382 383Enable migration to modern ObjC 384 385.. option:: -objcmt-migrate-annotation 386 387Enable migration to property and method annotations 388 389.. option:: -objcmt-migrate-designated-init 390 391Enable migration to infer NS\_DESIGNATED\_INITIALIZER for initializer methods 392 393.. option:: -objcmt-migrate-instancetype 394 395Enable migration to infer instancetype for method result type 396 397.. option:: -objcmt-migrate-literals 398 399Enable migration to modern ObjC literals 400 401.. option:: -objcmt-migrate-ns-macros 402 403Enable migration to NS\_ENUM/NS\_OPTIONS macros 404 405.. option:: -objcmt-migrate-property 406 407Enable migration to modern ObjC property 408 409.. option:: -objcmt-migrate-property-dot-syntax 410 411Enable migration of setter/getter messages to property-dot syntax 412 413.. option:: -objcmt-migrate-protocol-conformance 414 415Enable migration to add protocol conformance on classes 416 417.. option:: -objcmt-migrate-readonly-property 418 419Enable migration to modern ObjC readonly property 420 421.. option:: -objcmt-migrate-readwrite-property 422 423Enable migration to modern ObjC readwrite property 424 425.. option:: -objcmt-migrate-subscripting 426 427Enable migration to modern ObjC subscripting 428 429.. option:: -objcmt-ns-nonatomic-iosonly 430 431Enable migration to use NS\_NONATOMIC\_IOSONLY macro for setting property's 'atomic' attribute 432 433.. option:: -objcmt-returns-innerpointer-property 434 435Enable migration to annotate property with NS\_RETURNS\_INNER\_POINTER 436 437.. option:: -objcmt-whitelist-dir-path=<arg>, -objcmt-white-list-dir-path=<arg> 438 439Only modify files with a filename contained in the provided directory path 440 441.. option:: -object 442 443.. option:: -p, --profile 444 445.. option:: -pagezero\_size<arg> 446 447.. option:: -pg 448 449Enable mcount instrumentation 450 451.. option:: -pie 452 453.. option:: -pipe, --pipe 454 455Use pipes between commands, when possible 456 457.. option:: -prebind 458 459.. program:: clang1 460.. option:: -prebind\_all\_twolevel\_modules 461.. program:: clang 462 463.. option:: -preload 464 465.. option:: --print-diagnostic-categories 466 467.. option:: -print-effective-triple, --print-effective-triple 468 469Print the effective target triple 470 471.. option:: -print-file-name=<file>, --print-file-name=<file>, --print-file-name <arg> 472 473Print the full library path of <file> 474 475.. option:: -print-ivar-layout 476 477Enable Objective-C Ivar layout bitmap print trace 478 479.. option:: -print-libgcc-file-name, --print-libgcc-file-name 480 481Print the library path for the currently used compiler runtime library ("libgcc.a" or "libclang\_rt.builtins.\*.a") 482 483.. option:: -print-multi-directory, --print-multi-directory 484 485.. option:: -print-multi-lib, --print-multi-lib 486 487.. option:: -print-prog-name=<name>, --print-prog-name=<name>, --print-prog-name <arg> 488 489Print the full program path of <name> 490 491.. option:: -print-resource-dir, --print-resource-dir 492 493Print the resource directory pathname 494 495.. option:: -print-search-dirs, --print-search-dirs 496 497Print the paths used for finding libraries and programs 498 499.. option:: -print-target-triple, --print-target-triple 500 501Print the normalized target triple 502 503.. option:: -private\_bundle 504 505.. option:: -pthread, -no-pthread 506 507Support POSIX threads in generated code 508 509.. option:: -pthreads 510 511.. option:: -rdynamic 512 513.. option:: -read\_only\_relocs <arg> 514 515.. option:: -relocatable-pch, --relocatable-pch 516 517Whether to build a relocatable precompiled header 518 519.. option:: -remap 520 521.. option:: -rewrite-legacy-objc 522 523Rewrite Legacy Objective-C source to C++ 524 525.. option:: -rtlib=<arg>, --rtlib=<arg>, --rtlib <arg> 526 527Compiler runtime library to use 528 529.. option:: -save-stats=<arg>, --save-stats=<arg>, -save-stats (equivalent to -save-stats=cwd), --save-stats (equivalent to -save-stats=cwd) 530 531Save llvm statistics. 532 533.. option:: -save-temps=<arg>, --save-temps=<arg>, -save-temps (equivalent to -save-temps=cwd), --save-temps (equivalent to -save-temps=cwd) 534 535Save intermediate compilation results. 536 537.. option:: -sectalign <arg1> <arg2> <arg3> 538 539.. option:: -sectcreate <arg1> <arg2> <arg3> 540 541.. option:: -sectobjectsymbols <arg1> <arg2> 542 543.. option:: -sectorder <arg1> <arg2> <arg3> 544 545.. option:: -seg1addr<arg> 546 547.. option:: -seg\_addr\_table <arg> 548 549.. program:: clang1 550.. option:: -seg\_addr\_table\_filename <arg> 551.. program:: clang 552 553.. option:: -segaddr <arg1> <arg2> 554 555.. option:: -segcreate <arg1> <arg2> <arg3> 556 557.. option:: -seglinkedit 558 559.. option:: -segprot <arg1> <arg2> <arg3> 560 561.. option:: -segs\_read\_<arg> 562 563.. program:: clang1 564.. option:: -segs\_read\_only\_addr <arg> 565.. program:: clang 566 567.. program:: clang2 568.. option:: -segs\_read\_write\_addr <arg> 569.. program:: clang 570 571.. option:: -serialize-diagnostics <arg>, --serialize-diagnostics <arg> 572 573Serialize compiler diagnostics to a file 574 575.. option:: -shared, --shared 576 577.. option:: -shared-libgcc 578 579.. option:: -shared-libsan, -shared-libasan 580 581Dynamically link the sanitizer runtime 582 583.. option:: -single\_module 584 585.. option:: -specs=<arg>, --specs=<arg> 586 587.. option:: -static, --static 588 589.. option:: -static-libgcc 590 591.. option:: -static-libsan 592 593Statically link the sanitizer runtime 594 595.. option:: -static-libstdc++ 596 597.. option:: -std-default=<arg> 598 599.. option:: -stdlib=<arg>, --stdlib=<arg>, --stdlib <arg> 600 601C++ standard library to use 602 603.. option:: -sub\_library<arg> 604 605.. program:: clang1 606.. option:: -sub\_umbrella<arg> 607.. program:: clang 608 609.. option:: --sysroot=<arg>, --sysroot <arg> 610 611.. option:: --target-help 612 613.. option:: --target=<arg>, -target <arg> 614 615Generate code for the given target 616 617.. option:: --print-supported-cpus 618 619Print supported cpu models for the given target 620 621.. option:: -time 622 623Time individual commands 624 625.. option:: -traditional, --traditional 626 627.. option:: -traditional-cpp, --traditional-cpp 628 629Enable some traditional CPP emulation 630 631.. option:: -twolevel\_namespace 632 633.. program:: clang1 634.. option:: -twolevel\_namespace\_hints 635.. program:: clang 636 637.. option:: -umbrella <arg> 638 639.. option:: -unexported\_symbols\_list <arg> 640 641.. option:: -v, --verbose 642 643Show commands to run and use verbose output 644 645.. option:: --verify-debug-info 646 647Verify the binary representation of debug output 648 649.. option:: --version 650 651Print version information 652 653.. option:: -w, --no-warnings 654 655Suppress all warnings 656 657.. option:: -weak-l<arg> 658 659.. option:: -weak\_framework <arg> 660 661.. program:: clang1 662.. option:: -weak\_library <arg> 663.. program:: clang 664 665.. program:: clang2 666.. option:: -weak\_reference\_mismatches <arg> 667.. program:: clang 668 669.. option:: -whatsloaded 670 671.. option:: -whyload 672 673.. option:: -working-directory<arg>, -working-directory=<arg> 674 675Resolve file paths relative to the specified directory 676 677.. option:: -x<language>, --language <arg>, --language=<arg> 678 679Treat subsequent input files as having type <language> 680 681.. option:: -y<arg> 682 683Actions 684======= 685The action to perform on the input. 686 687.. option:: -E, --preprocess 688 689Only run the preprocessor 690 691.. option:: -S, --assemble 692 693Only run preprocess and compilation steps 694 695.. option:: -c, --compile 696 697Only run preprocess, compile, and assemble steps 698 699.. option:: -emit-llvm 700 701Use the LLVM representation for assembler and object files 702 703.. option:: -fsyntax-only 704 705.. option:: -module-file-info 706 707Provide information about a particular module file 708 709.. option:: --precompile 710 711Only precompile the input 712 713.. option:: -rewrite-objc 714 715Rewrite Objective-C source to C++ 716 717.. option:: -verify-pch 718 719Load and verify that a pre-compiled header file is not stale 720 721Compilation flags 722================= 723 724Flags controlling the behavior of Clang during compilation. These flags have 725no effect during actions that do not perform compilation. 726 727.. option:: -Xassembler <arg> 728 729Pass <arg> to the assembler 730 731.. option:: -Xclang <arg> 732 733Pass <arg> to the clang compiler 734 735.. option:: -fclang-abi-compat=<version> 736 737Attempt to match the ABI of Clang <version> 738 739.. option:: -fcomment-block-commands=<arg>,<arg2>... 740 741Treat each comma separated argument in <arg> as a documentation comment block command 742 743.. option:: -fcomplete-member-pointers, -fno-complete-member-pointers 744 745Require member pointer base types to be complete if they would be significant under the Microsoft ABI 746 747.. option:: -fcrash-diagnostics-dir=<arg> 748 749.. option:: -fdeclspec, -fno-declspec 750 751Allow \_\_declspec as a keyword 752 753.. option:: -fdepfile-entry=<arg> 754 755.. option:: -fdiagnostics-fixit-info, -fno-diagnostics-fixit-info 756 757.. option:: -fdiagnostics-format=<arg> 758 759.. option:: -fdiagnostics-parseable-fixits 760 761Print fix-its in machine parseable form 762 763.. option:: -fdiagnostics-print-source-range-info 764 765Print source range spans in numeric form 766 767.. option:: -fdiagnostics-show-category=<arg> 768 769.. option:: -fdiscard-value-names, -fno-discard-value-names 770 771Discard value names in LLVM IR 772 773.. option:: -fexperimental-isel, -fno-experimental-isel 774 775Enables the experimental global instruction selector 776 777.. option:: -fexperimental-new-pass-manager, -fno-experimental-new-pass-manager 778 779Enables an experimental new pass manager in LLVM. 780 781.. option:: -ffine-grained-bitfield-accesses, -fno-fine-grained-bitfield-accesses 782 783Use separate accesses for consecutive bitfield runs with legal widths and alignments. 784 785.. option:: -finline-functions, -fno-inline-functions 786 787Inline suitable functions 788 789.. option:: -finline-hint-functions 790 791Inline functions which are (explicitly or implicitly) marked inline 792 793.. option:: -fno-crash-diagnostics 794 795Disable auto-generation of preprocessed source files and a script for reproduction during a clang crash 796 797.. option:: -fno-sanitize-blacklist 798 799Don't use blacklist file for sanitizers 800 801.. option:: -fparse-all-comments 802 803.. option:: -frecord-command-line, -frecord-gcc-switches, -fno-record-command-line, -fno-record-gcc-switches 804 805Generate a section named ".GCC.command.line" containing the clang driver 806command-line. After linking, the section may contain multiple command lines, 807which will be individually terminated by null bytes. Separate arguments within 808a command line are combined with spaces; spaces and backslashes within an 809argument are escaped with backslashes. This format differs from the format of 810the equivalent section produced by GCC with the -frecord-gcc-switches flag. 811This option is currently only supported on ELF targets. 812 813.. option:: -fsanitize-address-field-padding=<arg> 814 815Level of field padding for AddressSanitizer 816 817.. option:: -fsanitize-address-globals-dead-stripping 818 819Enable linker dead stripping of globals in AddressSanitizer 820 821.. option:: -fsanitize-address-use-odr-indicator, -fno-sanitize-address-use-odr-indicator 822 823Enable ODR indicator globals to avoid false ODR violation reports in partially sanitized programs at the cost of an increase in binary size 824 825.. option:: -fsanitize-address-poison-custom-array-cookie, -fno-sanitize-address-poison-custom-array-cookie 826 827Enable "poisoning" array cookies when allocating arrays with a custom operator new\[\] in Address Sanitizer, preventing accesses to the cookies from user code. An array cookie is a small implementation-defined header added to certain array allocations to record metadata such as the length of the array. Accesses to array cookies from user code are technically allowed by the standard but are more likely to be the result of an out-of-bounds array access. 828 829An operator new\[\] is "custom" if it is not one of the allocation functions provided by the C++ standard library. Array cookies from non-custom allocation functions are always poisoned. 830 831.. option:: -fsanitize-address-use-after-scope, -fno-sanitize-address-use-after-scope 832 833Enable use-after-scope detection in AddressSanitizer 834 835.. option:: -fsanitize-blacklist=<arg> 836 837Path to blacklist file for sanitizers 838 839.. option:: -fsanitize-cfi-cross-dso, -fno-sanitize-cfi-cross-dso 840 841Enable control flow integrity (CFI) checks for cross-DSO calls. 842 843.. option:: -fsanitize-cfi-icall-generalize-pointers 844 845Generalize pointers in CFI indirect call type signature checks 846 847.. option:: -fsanitize-coverage=<arg1>,<arg2>..., -fno-sanitize-coverage=<arg1>,<arg2>... 848 849Specify the type of coverage instrumentation for Sanitizers 850 851.. option:: -fsanitize-link-c++-runtime 852 853.. option:: -fsanitize-memory-track-origins, -fno-sanitize-memory-track-origins 854 855Enable origins tracking in MemorySanitizer 856 857.. program:: clang1 858.. option:: -fsanitize-memory-track-origins=<arg> 859.. program:: clang 860 861Enable origins tracking in MemorySanitizer 862 863.. option:: -fsanitize-memory-use-after-dtor, -fno-sanitize-memory-use-after-dtor 864 865Enable use-after-destroy detection in MemorySanitizer 866 867.. option:: -fsanitize-minimal-runtime, -fno-sanitize-minimal-runtime 868 869.. option:: -fsanitize-recover, -fno-sanitize-recover 870 871.. program:: clang1 872.. option:: -fsanitize-recover=<arg1>,<arg2>..., -fno-sanitize-recover=<arg1>,<arg2>... 873.. program:: clang 874 875Enable recovery for specified sanitizers 876 877.. option:: -fsanitize-stats, -fno-sanitize-stats 878 879Enable sanitizer statistics gathering. 880 881.. option:: -fsanitize-thread-atomics, -fno-sanitize-thread-atomics 882 883Enable atomic operations instrumentation in ThreadSanitizer (default) 884 885.. option:: -fsanitize-thread-func-entry-exit, -fno-sanitize-thread-func-entry-exit 886 887Enable function entry/exit instrumentation in ThreadSanitizer (default) 888 889.. option:: -fsanitize-thread-memory-access, -fno-sanitize-thread-memory-access 890 891Enable memory access instrumentation in ThreadSanitizer (default) 892 893.. option:: -fsanitize-trap=<arg1>,<arg2>..., -fno-sanitize-trap=<arg1>,<arg2>... 894 895Enable trapping for specified sanitizers 896 897.. option:: -fsanitize-undefined-strip-path-components=<number> 898 899Strip (or keep only, if negative) a given number of path components when emitting check metadata. 900 901.. option:: -fsanitize-undefined-trap-on-error, -fno-sanitize-undefined-trap-on-error 902 903.. option:: -fsanitize=<check>,<arg2>..., -fno-sanitize=<arg1>,<arg2>... 904 905Turn on runtime checks for various forms of undefined or suspicious behavior. See user manual for available checks 906 907.. option:: -moutline, -mno-outline 908 909Enable function outlining (AArch64 only) 910 911.. option:: --param <arg>, --param=<arg> 912 913.. option:: -std=<arg>, --std=<arg>, --std <arg> 914 915Language standard to compile for 916 917Preprocessor flags 918~~~~~~~~~~~~~~~~~~ 919 920Flags controlling the behavior of the Clang preprocessor. 921 922.. option:: -C, --comments 923 924Include comments in preprocessed output 925 926.. option:: -CC, --comments-in-macros 927 928Include comments from within macros in preprocessed output 929 930.. option:: -D<macro>=<value>, --define-macro <arg>, --define-macro=<arg> 931 932Define <macro> to <value> (or 1 if <value> omitted) 933 934.. option:: -H, --trace-includes 935 936Show header includes and nesting depth 937 938.. option:: -P, --no-line-commands 939 940Disable linemarker output in -E mode 941 942.. option:: -U<macro>, --undefine-macro <arg>, --undefine-macro=<arg> 943 944Undefine macro <macro> 945 946.. option:: -Wp,<arg>,<arg2>... 947 948Pass the comma separated arguments in <arg> to the preprocessor 949 950.. option:: -Xpreprocessor <arg> 951 952Pass <arg> to the preprocessor 953 954Include path management 955----------------------- 956 957Flags controlling how ``#include``\s are resolved to files. 958 959.. option:: -I<dir>, --include-directory <arg>, --include-directory=<arg> 960 961Add directory to include search path 962 963.. option:: -I-, --include-barrier 964 965Restrict all prior -I flags to double-quoted inclusion and remove current directory from include path 966 967.. option:: --cuda-path-ignore-env 968 969Ignore environment variables to detect CUDA installation 970 971.. option:: --cuda-path=<arg> 972 973CUDA installation path 974 975.. option:: -cxx-isystem<directory> 976 977Add directory to the C++ SYSTEM include search path 978 979.. option:: -fbuild-session-file=<file> 980 981Use the last modification time of <file> as the build session timestamp 982 983.. option:: -fbuild-session-timestamp=<time since Epoch in seconds> 984 985Time when the current build session started 986 987.. option:: -fmodule-file=\[<name>=\]<file> 988 989Specify the mapping of module name to precompiled module file, or load a module file if name is omitted. 990 991.. option:: -fmodules-cache-path=<directory> 992 993Specify the module cache path 994 995.. option:: -fmodules-disable-diagnostic-validation 996 997Disable validation of the diagnostic options when loading the module 998 999.. option:: -fmodules-prune-after=<seconds> 1000 1001Specify the interval (in seconds) after which a module file will be considered unused 1002 1003.. option:: -fmodules-prune-interval=<seconds> 1004 1005Specify the interval (in seconds) between attempts to prune the module cache 1006 1007.. option:: -fmodules-user-build-path <directory> 1008 1009Specify the module user build path 1010 1011.. option:: -fmodules-validate-once-per-build-session 1012 1013Don't verify input files for the modules if the module has been successfully validated or loaded during this build session 1014 1015.. option:: -fmodules-validate-system-headers, -fno-modules-validate-system-headers 1016 1017Validate the system headers that a module depends on when loading the module 1018 1019.. option:: -fprebuilt-module-path=<directory> 1020 1021Specify the prebuilt module path 1022 1023.. option:: -idirafter<arg>, --include-directory-after <arg>, --include-directory-after=<arg> 1024 1025Add directory to AFTER include search path 1026 1027.. option:: -iframework<arg> 1028 1029Add directory to SYSTEM framework search path 1030 1031.. option:: -iframeworkwithsysroot<directory> 1032 1033Add directory to SYSTEM framework search path, absolute paths are relative to -isysroot 1034 1035.. option:: -imacros<file>, --imacros<file>, --imacros=<arg> 1036 1037Include macros from file before parsing 1038 1039.. option:: -include<file>, --include<file>, --include=<arg> 1040 1041Include file before parsing 1042 1043.. option:: -include-pch <file> 1044 1045Include precompiled header file 1046 1047.. option:: -iprefix<dir>, --include-prefix <arg>, --include-prefix=<arg> 1048 1049Set the -iwithprefix/-iwithprefixbefore prefix 1050 1051.. option:: -iquote<directory> 1052 1053Add directory to QUOTE include search path 1054 1055.. option:: -isysroot<dir> 1056 1057Set the system root directory (usually /) 1058 1059.. option:: -isystem<directory> 1060 1061Add directory to SYSTEM include search path 1062 1063.. option:: -isystem-after<directory> 1064 1065Add directory to end of the SYSTEM include search path 1066 1067.. option:: -ivfsoverlay<arg> 1068 1069Overlay the virtual filesystem described by file over the real file system 1070 1071.. option:: -iwithprefix<dir>, --include-with-prefix <arg>, --include-with-prefix-after <arg>, --include-with-prefix-after=<arg>, --include-with-prefix=<arg> 1072 1073Set directory to SYSTEM include search path with prefix 1074 1075.. option:: -iwithprefixbefore<dir>, --include-with-prefix-before <arg>, --include-with-prefix-before=<arg> 1076 1077Set directory to include search path with prefix 1078 1079.. option:: -iwithsysroot<directory> 1080 1081Add directory to SYSTEM include search path, absolute paths are relative to -isysroot 1082 1083.. option:: --ptxas-path=<arg> 1084 1085Path to ptxas (used for compiling CUDA code) 1086 1087.. option:: --system-header-prefix=<prefix>, --no-system-header-prefix=<prefix>, --system-header-prefix <arg> 1088 1089Treat all #include paths starting with <prefix> as including a system header. 1090 1091Dependency file generation 1092-------------------------- 1093 1094Flags controlling generation of a dependency file for ``make``-like build 1095systems. 1096 1097.. option:: -M, --dependencies 1098 1099Like -MD, but also implies -E and writes to stdout by default 1100 1101.. option:: -MD, --write-dependencies 1102 1103Write a depfile containing user and system headers 1104 1105.. option:: -MF<file> 1106 1107Write depfile output from -MMD, -MD, -MM, or -M to <file> 1108 1109.. option:: -MG, --print-missing-file-dependencies 1110 1111Add missing headers to depfile 1112 1113.. option:: -MJ<arg> 1114 1115Write a compilation database entry per input 1116 1117.. option:: -MM, --user-dependencies 1118 1119Like -MMD, but also implies -E and writes to stdout by default 1120 1121.. option:: -MMD, --write-user-dependencies 1122 1123Write a depfile containing user headers 1124 1125.. option:: -MP 1126 1127Create phony target for each dependency (other than main file) 1128 1129.. option:: -MQ<arg> 1130 1131Specify name of main file output to quote in depfile 1132 1133.. option:: -MT<arg> 1134 1135Specify name of main file output in depfile 1136 1137.. option:: -MV 1138 1139Use NMake/Jom format for the depfile 1140 1141Dumping preprocessor state 1142-------------------------- 1143 1144Flags allowing the state of the preprocessor to be dumped in various ways. 1145 1146.. option:: -d 1147 1148.. program:: clang1 1149.. option:: -d<arg> 1150.. program:: clang 1151 1152.. option:: -dD 1153 1154Print macro definitions in -E mode in addition to normal output 1155 1156.. option:: -dI 1157 1158Print include directives in -E mode in addition to normal output 1159 1160.. option:: -dM 1161 1162Print macro definitions in -E mode instead of normal output 1163 1164Diagnostic flags 1165~~~~~~~~~~~~~~~~ 1166 1167Flags controlling which warnings, errors, and remarks Clang will generate. 1168See the :doc:`full list of warning and remark flags <DiagnosticsReference>`. 1169 1170.. option:: -R<remark> 1171 1172Enable the specified remark 1173 1174.. option:: -Rpass-analysis=<arg> 1175 1176Report transformation analysis from optimization passes whose name matches the given POSIX regular expression 1177 1178.. option:: -Rpass-missed=<arg> 1179 1180Report missed transformations by optimization passes whose name matches the given POSIX regular expression 1181 1182.. option:: -Rpass=<arg> 1183 1184Report transformations performed by optimization passes whose name matches the given POSIX regular expression 1185 1186.. option:: -W<warning>, --extra-warnings, --warn-<arg>, --warn-=<arg> 1187 1188Enable the specified warning 1189 1190.. option:: -Wdeprecated, -Wno-deprecated 1191 1192Enable warnings for deprecated constructs and define \_\_DEPRECATED 1193 1194.. option:: -Wnonportable-cfstrings<arg>, -Wno-nonportable-cfstrings<arg> 1195 1196Target-independent compilation options 1197~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1198.. option:: -Wframe-larger-than=<arg> 1199 1200.. option:: -fPIC, -fno-PIC 1201 1202.. option:: -fPIE, -fno-PIE 1203 1204.. option:: -faccess-control, -fno-access-control 1205 1206.. option:: -faddrsig, -fno-addrsig 1207 1208Emit an address-significance table 1209 1210.. option:: -falign-functions, -fno-align-functions 1211 1212.. program:: clang1 1213.. option:: -falign-functions=<arg> 1214.. program:: clang 1215 1216.. program:: clang1 1217.. option:: -faligned-allocation, -faligned-new, -fno-aligned-allocation 1218.. program:: clang 1219 1220Enable C++17 aligned allocation functions 1221 1222.. option:: -fallow-editor-placeholders, -fno-allow-editor-placeholders 1223 1224Treat editor placeholders as valid source code 1225 1226.. option:: -fallow-unsupported 1227 1228.. option:: -faltivec, -fno-altivec 1229 1230.. option:: -fansi-escape-codes 1231 1232Use ANSI escape codes for diagnostics 1233 1234.. option:: -fapple-kext, -findirect-virtual-calls, -fterminated-vtables 1235 1236Use Apple's kernel extensions ABI 1237 1238.. option:: -fapple-pragma-pack, -fno-apple-pragma-pack 1239 1240Enable Apple gcc-compatible #pragma pack handling 1241 1242.. option:: -fapplication-extension, -fno-application-extension 1243 1244Restrict code to those available for App Extensions 1245 1246.. option:: -fasm, -fno-asm 1247 1248.. option:: -fasm-blocks, -fno-asm-blocks 1249 1250.. option:: -fassociative-math, -fno-associative-math 1251 1252.. option:: -fassume-sane-operator-new, -fno-assume-sane-operator-new 1253 1254.. option:: -fast 1255 1256.. option:: -fastcp 1257 1258.. option:: -fastf 1259 1260.. option:: -fasynchronous-unwind-tables, -fno-asynchronous-unwind-tables 1261 1262.. option:: -fautolink, -fno-autolink 1263 1264.. option:: -fblocks, -fno-blocks 1265 1266Enable the 'blocks' language feature 1267 1268.. option:: -fbootclasspath=<arg>, --bootclasspath <arg>, --bootclasspath=<arg> 1269 1270.. option:: -fborland-extensions, -fno-borland-extensions 1271 1272Accept non-standard constructs supported by the Borland compiler 1273 1274.. option:: -fbracket-depth=<arg> 1275 1276.. option:: -fbuiltin, -fno-builtin 1277 1278.. option:: -fbuiltin-module-map 1279 1280Load the clang builtins module map file. 1281 1282.. option:: -fc++-static-destructors, -fno-c++-static-destructors 1283 1284Enable C++ static destructor registration (the default) 1285 1286.. option:: -fcaret-diagnostics, -fno-caret-diagnostics 1287 1288.. option:: -fcf-protection=<arg>, -fcf-protection (equivalent to -fcf-protection=full) 1289 1290Instrument control-flow architecture protection. Options: return, branch, full, none. 1291 1292.. option:: -fchar8\_t, -fno-char8\_t 1293 1294Enable C++ builtin type char8\_t 1295 1296.. option:: -fclasspath=<arg>, --CLASSPATH <arg>, --CLASSPATH=<arg>, --classpath <arg>, --classpath=<arg> 1297 1298.. option:: -fcolor-diagnostics, -fno-color-diagnostics 1299 1300Use colors in diagnostics 1301 1302.. option:: -fcommon, -fno-common 1303 1304.. option:: -fcompile-resource=<arg>, --resource <arg>, --resource=<arg> 1305 1306.. option:: -fconstant-cfstrings, -fno-constant-cfstrings 1307 1308.. option:: -fconstant-string-class=<arg> 1309 1310.. option:: -fconstexpr-backtrace-limit=<arg> 1311 1312.. option:: -fconstexpr-depth=<arg> 1313 1314.. option:: -fconstexpr-steps=<arg> 1315 1316.. option:: -fcoroutines-ts, -fno-coroutines-ts 1317 1318Enable support for the C++ Coroutines TS 1319 1320.. option:: -fcoverage-mapping, -fno-coverage-mapping 1321 1322Generate coverage mapping to enable code coverage analysis 1323 1324.. option:: -fcreate-profile 1325 1326.. option:: -fcxx-exceptions, -fno-cxx-exceptions 1327 1328Enable C++ exceptions 1329 1330.. option:: -fcxx-modules, -fno-cxx-modules 1331 1332.. option:: -fdata-sections, -fno-data-sections 1333 1334Place each data in its own section (ELF Only) 1335 1336.. option:: -fdebug-info-for-profiling, -fno-debug-info-for-profiling 1337 1338Emit extra debug info to make sample profile more accurate. 1339 1340.. option:: -fdebug-macro, -fno-debug-macro 1341 1342Emit macro debug information 1343 1344.. option:: -fdebug-pass-arguments 1345 1346.. option:: -fdebug-pass-structure 1347 1348.. option:: -fdebug-prefix-map=<arg> 1349 1350remap file source paths in debug info 1351 1352.. option:: -fdebug-types-section, -fno-debug-types-section 1353 1354Place debug types in their own section (ELF Only) 1355 1356.. option:: -fdelayed-template-parsing, -fno-delayed-template-parsing 1357 1358Parse templated function definitions at the end of the translation unit 1359 1360.. option:: -fdelete-null-pointer-checks, -fno-delete-null-pointer-checks 1361 1362Treat usage of null pointers as undefined behavior. 1363 1364.. option:: -fdenormal-fp-math=<arg> 1365 1366.. option:: -fdiagnostics-absolute-paths 1367 1368Print absolute paths in diagnostics 1369 1370.. option:: -fdiagnostics-color, -fno-diagnostics-color 1371 1372.. program:: clang1 1373.. option:: -fdiagnostics-color=<arg> 1374.. program:: clang 1375 1376.. option:: -fdiagnostics-hotness-threshold=<number> 1377 1378Prevent optimization remarks from being output if they do not have at least this profile count 1379 1380.. option:: -fdiagnostics-show-hotness, -fno-diagnostics-show-hotness 1381 1382Enable profile hotness information in diagnostic line 1383 1384.. option:: -fdiagnostics-show-note-include-stack, -fno-diagnostics-show-note-include-stack 1385 1386Display include stacks for diagnostic notes 1387 1388.. option:: -fdiagnostics-show-option, -fno-diagnostics-show-option 1389 1390Print option name with mappable diagnostics 1391 1392.. option:: -fdiagnostics-show-template-tree 1393 1394Print a template comparison tree for differing templates 1395 1396.. option:: -fdigraphs, -fno-digraphs 1397 1398Enable alternative token representations '<:', ':>', '<%', '%>', '%:', '%:%:' (default) 1399 1400.. option:: -fdollars-in-identifiers, -fno-dollars-in-identifiers 1401 1402Allow '$' in identifiers 1403 1404.. option:: -fdouble-square-bracket-attributes, -fno-double-square-bracket-attributes 1405 1406Enable '\[\[\]\]' attributes in all C and C++ language modes 1407 1408.. option:: -fdwarf-directory-asm, -fno-dwarf-directory-asm 1409 1410.. option:: -fdwarf-exceptions 1411 1412Use DWARF style exceptions 1413 1414.. option:: -felide-constructors, -fno-elide-constructors 1415 1416.. option:: -feliminate-unused-debug-symbols, -fno-eliminate-unused-debug-symbols 1417 1418.. option:: -fembed-bitcode=<option>, -fembed-bitcode (equivalent to -fembed-bitcode=all), -fembed-bitcode-marker (equivalent to -fembed-bitcode=marker) 1419 1420Embed LLVM bitcode (option: off, all, bitcode, marker) 1421 1422.. option:: -femit-all-decls 1423 1424Emit all declarations, even if unused 1425 1426.. option:: -femulated-tls, -fno-emulated-tls 1427 1428Use emutls functions to access thread\_local variables 1429 1430.. option:: -fencoding=<arg>, --encoding <arg>, --encoding=<arg> 1431 1432.. option:: -ferror-limit=<arg> 1433 1434.. option:: -fescaping-block-tail-calls, -fno-escaping-block-tail-calls 1435 1436.. option:: -fexceptions, -fno-exceptions 1437 1438Enable support for exception handling 1439 1440.. option:: -fexec-charset=<arg> 1441 1442.. option:: -fextdirs=<arg>, --extdirs <arg>, --extdirs=<arg> 1443 1444.. option:: -ffast-math, -fno-fast-math 1445 1446Allow aggressive, lossy floating-point optimizations 1447 1448.. option:: -ffinite-math-only, -fno-finite-math-only 1449 1450.. option:: -ffixed-point, -fno-fixed-point 1451 1452Enable fixed point types 1453 1454.. option:: -ffor-scope, -fno-for-scope 1455 1456.. option:: -fforce-emit-vtables, -fno-force-emit-vtables 1457 1458Emits more virtual tables to improve devirtualization 1459 1460.. option:: -fforce-enable-int128, -fno-force-enable-int128 1461 1462Enable support for int128\_t type 1463 1464.. option:: -ffp-contract=<arg> 1465 1466Form fused FP ops (e.g. FMAs): fast (everywhere) \| on (according to FP\_CONTRACT pragma, default) \| off (never fuse) 1467 1468.. option:: -ffreestanding 1469 1470Assert that the compilation takes place in a freestanding environment 1471 1472.. option:: -ffunction-sections, -fno-function-sections 1473 1474Place each function in its own section (ELF Only) 1475 1476.. option:: -fgnu-inline-asm, -fno-gnu-inline-asm 1477 1478.. option:: -fgnu-keywords, -fno-gnu-keywords 1479 1480Allow GNU-extension keywords regardless of language standard 1481 1482.. option:: -fgnu-runtime 1483 1484Generate output compatible with the standard GNU Objective-C runtime 1485 1486.. option:: -fgnu89-inline, -fno-gnu89-inline 1487 1488Use the gnu89 inline semantics 1489 1490.. option:: -fhonor-infinities, -fhonor-infinites, -fno-honor-infinities 1491 1492.. option:: -fhonor-nans, -fno-honor-nans 1493 1494.. option:: -fhosted 1495 1496.. option:: -fimplicit-module-maps, -fmodule-maps, -fno-implicit-module-maps 1497 1498Implicitly search the file system for module map files. 1499 1500.. option:: -fimplicit-modules, -fno-implicit-modules 1501 1502.. option:: -finput-charset=<arg> 1503 1504.. option:: -finstrument-function-entry-bare 1505 1506Instrument function entry only, after inlining, without arguments to the instrumentation call 1507 1508.. option:: -finstrument-functions 1509 1510Generate calls to instrument function entry and exit 1511 1512.. option:: -finstrument-functions-after-inlining 1513 1514Like -finstrument-functions, but insert the calls after inlining 1515 1516.. option:: -fintegrated-as, -fno-integrated-as, -integrated-as 1517 1518Enable the integrated assembler 1519 1520.. option:: -fjump-tables, -fno-jump-tables 1521 1522.. option:: -fkeep-static-consts 1523 1524Keep static const variables even if unused 1525 1526.. option:: -flax-vector-conversions, -fno-lax-vector-conversions 1527 1528.. option:: -flimited-precision=<arg> 1529 1530.. option:: -flto, -fno-lto 1531 1532Enable LTO in 'full' mode 1533 1534.. option:: -flto-jobs=<arg> 1535 1536Controls the backend parallelism of -flto=thin (default of 0 means the number of threads will be derived from the number of CPUs detected) 1537 1538.. program:: clang1 1539.. option:: -flto=<arg> 1540.. program:: clang 1541 1542Set LTO mode to either 'full' or 'thin' 1543 1544.. option:: -fmacro-backtrace-limit=<arg> 1545 1546.. option:: -fmath-errno, -fno-math-errno 1547 1548Require math functions to indicate errors by setting errno 1549 1550.. option:: -fmax-type-align=<arg> 1551 1552Specify the maximum alignment to enforce on pointers lacking an explicit alignment 1553 1554.. option:: -fmerge-all-constants, -fno-merge-all-constants 1555 1556Allow merging of constants 1557 1558.. option:: -fmessage-length=<arg> 1559 1560.. option:: -fmodule-file-deps, -fno-module-file-deps 1561 1562.. option:: -fmodule-map-file=<file> 1563 1564Load this module map file 1565 1566.. option:: -fmodule-name=<name>, -fmodule-implementation-of <arg>, -fmodule-name <arg> 1567 1568Specify the name of the module to build 1569 1570.. option:: -fmodules, -fno-modules 1571 1572Enable the 'modules' language feature 1573 1574.. option:: -fmodules-decluse, -fno-modules-decluse 1575 1576Require declaration of modules used within a module 1577 1578.. option:: -fmodules-ignore-macro=<arg> 1579 1580Ignore the definition of the given macro when building and loading modules 1581 1582.. option:: -fmodules-search-all, -fno-modules-search-all 1583 1584Search even non-imported modules to resolve references 1585 1586.. option:: -fmodules-strict-decluse 1587 1588Like -fmodules-decluse but requires all headers to be in modules 1589 1590.. option:: -fmodules-ts 1591 1592Enable support for the C++ Modules TS 1593 1594.. option:: -fms-compatibility, -fno-ms-compatibility 1595 1596Enable full Microsoft Visual C++ compatibility 1597 1598.. option:: -fms-compatibility-version=<arg> 1599 1600Dot-separated value representing the Microsoft compiler version number to report in \_MSC\_VER (0 = don't define it (default)) 1601 1602.. option:: -fms-extensions, -fno-ms-extensions 1603 1604Accept some non-standard constructs supported by the Microsoft compiler 1605 1606.. option:: -fms-memptr-rep=<arg> 1607 1608.. option:: -fms-volatile<arg> 1609 1610.. option:: -fmsc-version=<arg> 1611 1612Microsoft compiler version number to report in \_MSC\_VER (0 = don't define it (default)) 1613 1614.. option:: -fmudflap 1615 1616.. option:: -fmudflapth 1617 1618.. option:: -fnested-functions 1619 1620.. option:: -fnew-alignment=<align>, -fnew-alignment <arg> 1621 1622Specifies the largest alignment guaranteed by '::operator new(size\_t)' 1623 1624.. option:: -fnext-runtime 1625 1626.. option:: -fno-builtin-<arg> 1627 1628Disable implicit builtin knowledge of a specific function 1629 1630.. option:: -fno-elide-type 1631 1632Do not elide types when printing diagnostics 1633 1634.. option:: -fno-max-type-align 1635 1636.. option:: -fno-operator-names 1637 1638Do not treat C++ operator name keywords as synonyms for operators 1639 1640.. option:: -fno-rtti-data 1641 1642Control emission of RTTI data 1643 1644.. option:: -fno-strict-modules-decluse 1645 1646.. option:: -fno-working-directory 1647 1648.. option:: -fnoxray-link-deps 1649 1650.. option:: -fobjc-abi-version=<arg> 1651 1652.. option:: -fobjc-arc, -fno-objc-arc 1653 1654Synthesize retain and release calls for Objective-C pointers 1655 1656.. option:: -fobjc-arc-exceptions, -fno-objc-arc-exceptions 1657 1658Use EH-safe code when synthesizing retains and releases in -fobjc-arc 1659 1660.. option:: -fobjc-exceptions, -fno-objc-exceptions 1661 1662Enable Objective-C exceptions 1663 1664.. option:: -fobjc-infer-related-result-type, -fno-objc-infer-related-result-type 1665 1666.. option:: -fobjc-legacy-dispatch, -fno-objc-legacy-dispatch 1667 1668.. option:: -fobjc-link-runtime 1669 1670.. option:: -fobjc-nonfragile-abi, -fno-objc-nonfragile-abi 1671 1672.. option:: -fobjc-nonfragile-abi-version=<arg> 1673 1674.. option:: -fobjc-runtime=<arg> 1675 1676Specify the target Objective-C runtime kind and version 1677 1678.. option:: -fobjc-sender-dependent-dispatch 1679 1680.. option:: -fobjc-weak, -fno-objc-weak 1681 1682Enable ARC-style weak references in Objective-C 1683 1684.. option:: -fomit-frame-pointer, -fno-omit-frame-pointer 1685 1686.. option:: -fopenmp, -fno-openmp 1687 1688Parse OpenMP pragmas and generate parallel code. 1689 1690.. option:: -fopenmp-simd, -fno-openmp-simd 1691 1692Emit OpenMP code only for SIMD-based constructs. 1693 1694.. option:: -fopenmp-version=<arg> 1695 1696.. program:: clang1 1697.. option:: -fopenmp=<arg> 1698.. program:: clang 1699 1700.. option:: -foperator-arrow-depth=<arg> 1701 1702.. option:: -foptimization-record-file=<arg> 1703 1704Specify the file name of any generated YAML optimization record 1705 1706.. option:: -foptimize-sibling-calls, -fno-optimize-sibling-calls 1707 1708.. option:: -foutput-class-dir=<arg>, --output-class-directory <arg>, --output-class-directory=<arg> 1709 1710.. option:: -fpack-struct, -fno-pack-struct 1711 1712.. program:: clang1 1713.. option:: -fpack-struct=<arg> 1714.. program:: clang 1715 1716Specify the default maximum struct packing alignment 1717 1718.. option:: -fpascal-strings, -fno-pascal-strings, -mpascal-strings 1719 1720Recognize and construct Pascal-style string literals 1721 1722.. option:: -fpcc-struct-return 1723 1724Override the default ABI to return all structs on the stack 1725 1726.. option:: -fpch-preprocess 1727 1728.. option:: -fpic, -fno-pic 1729 1730.. option:: -fpie, -fno-pie 1731 1732.. option:: -fplt, -fno-plt 1733 1734Use the PLT to make function calls 1735 1736.. option:: -fplugin=<dsopath> 1737 1738Load the named plugin (dynamic shared object) 1739 1740.. option:: -fpreserve-as-comments, -fno-preserve-as-comments 1741 1742.. option:: -fprofile-arcs, -fno-profile-arcs 1743 1744.. option:: -fprofile-dir=<arg> 1745 1746.. option:: -fprofile-generate, -fno-profile-generate 1747 1748Generate instrumented code to collect execution counts into default.profraw (overridden by LLVM\_PROFILE\_FILE env var) 1749 1750.. program:: clang1 1751.. option:: -fprofile-generate=<directory> 1752.. program:: clang 1753 1754Generate instrumented code to collect execution counts into <directory>/default.profraw (overridden by LLVM\_PROFILE\_FILE env var) 1755 1756.. option:: -fprofile-instr-generate, -fno-profile-instr-generate 1757 1758Generate instrumented code to collect execution counts into default.profraw file (overridden by '=' form of option or LLVM\_PROFILE\_FILE env var) 1759 1760.. program:: clang1 1761.. option:: -fprofile-instr-generate=<file> 1762.. program:: clang 1763 1764Generate instrumented code to collect execution counts into <file> (overridden by LLVM\_PROFILE\_FILE env var) 1765 1766.. option:: -fprofile-instr-use, -fno-profile-instr-use, -fprofile-use 1767 1768.. program:: clang1 1769.. option:: -fprofile-instr-use=<arg> 1770.. program:: clang 1771 1772Use instrumentation data for profile-guided optimization 1773 1774.. option:: -fprofile-sample-accurate, -fauto-profile-accurate, -fno-profile-sample-accurate 1775 1776Specifies that the sample profile is accurate. If the sample 1777 profile is accurate, callsites without profile samples are marked 1778 as cold. Otherwise, treat callsites without profile samples as if 1779 we have no profile 1780 1781.. option:: -fprofile-sample-use, -fauto-profile, -fno-profile-sample-use 1782 1783.. program:: clang1 1784.. option:: -fprofile-sample-use=<arg>, -fauto-profile=<arg> 1785.. program:: clang 1786 1787Enable sample-based profile guided optimizations 1788 1789.. program:: clang1 1790.. option:: -fprofile-use=<pathname> 1791.. program:: clang 1792 1793Use instrumentation data for profile-guided optimization. If pathname is a directory, it reads from <pathname>/default.profdata. Otherwise, it reads from file <pathname>. 1794 1795.. option:: -freciprocal-math, -fno-reciprocal-math 1796 1797Allow division operations to be reassociated 1798 1799.. option:: -freg-struct-return 1800 1801Override the default ABI to return small structs in registers 1802 1803.. option:: -fregister-global-dtors-with-atexit, -fno-register-global-dtors-with-atexit 1804 1805Use atexit or \_\_cxa\_atexit to register global destructors 1806 1807.. option:: -frelaxed-template-template-args, -fno-relaxed-template-template-args 1808 1809Enable C++17 relaxed template template argument matching 1810 1811.. option:: -freroll-loops, -fno-reroll-loops 1812 1813Turn on loop reroller 1814 1815.. option:: -fretain-comments-from-system-headers 1816 1817.. option:: -frewrite-imports, -fno-rewrite-imports 1818 1819.. option:: -frewrite-includes, -fno-rewrite-includes 1820 1821.. option:: -frewrite-map-file <arg> 1822 1823.. program:: clang1 1824.. option:: -frewrite-map-file=<arg> 1825.. program:: clang 1826 1827.. option:: -fropi, -fno-ropi 1828 1829.. option:: -frtti, -fno-rtti 1830 1831.. option:: -frwpi, -fno-rwpi 1832 1833.. option:: -fsave-optimization-record, -fno-save-optimization-record 1834 1835Generate a YAML optimization record file 1836 1837.. option:: -fseh-exceptions 1838 1839Use SEH style exceptions 1840 1841.. option:: -fshort-enums, -fno-short-enums 1842 1843Allocate to an enum type only as many bytes as it needs for the declared range of possible values 1844 1845.. option:: -fshort-wchar, -fno-short-wchar 1846 1847Force wchar\_t to be a short unsigned int 1848 1849.. option:: -fshow-column, -fno-show-column 1850 1851.. option:: -fshow-overloads=<arg> 1852 1853Which overload candidates to show when overload resolution fails: best\|all; defaults to all 1854 1855.. option:: -fshow-source-location, -fno-show-source-location 1856 1857.. option:: -fsignaling-math, -fno-signaling-math 1858 1859.. option:: -fsigned-bitfields 1860 1861.. option:: -fsigned-char, -fno-signed-char, --signed-char 1862 1863.. option:: -fsigned-zeros, -fno-signed-zeros 1864 1865.. option:: -fsized-deallocation, -fno-sized-deallocation 1866 1867Enable C++14 sized global deallocation functions 1868 1869.. option:: -fsjlj-exceptions 1870 1871Use SjLj style exceptions 1872 1873.. option:: -fslp-vectorize, -fno-slp-vectorize, -ftree-slp-vectorize 1874 1875Enable the superword-level parallelism vectorization passes 1876 1877.. option:: -fspell-checking, -fno-spell-checking 1878 1879.. option:: -fspell-checking-limit=<arg> 1880 1881.. option:: -fsplit-dwarf-inlining, -fno-split-dwarf-inlining 1882 1883Provide minimal debug info in the object/executable to facilitate online symbolication/stack traces in the absence of .dwo/.dwp files when using Split DWARF 1884 1885.. option:: -fsplit-stack 1886 1887.. option:: -fstack-protector, -fno-stack-protector 1888 1889Enable stack protectors for functions potentially vulnerable to stack smashing 1890 1891.. option:: -fstack-protector-all 1892 1893Force the usage of stack protectors for all functions 1894 1895.. option:: -fstack-protector-strong 1896 1897Use a strong heuristic to apply stack protectors to functions 1898 1899.. option:: -fstack-size-section, -fno-stack-size-section 1900 1901Emit section containing metadata on function stack sizes 1902 1903.. option:: -fstandalone-debug, -fno-limit-debug-info, -fno-standalone-debug 1904 1905Emit full debug info for all types used by the program 1906 1907.. option:: -fstrict-aliasing, -fno-strict-aliasing 1908 1909.. option:: -fstrict-enums, -fno-strict-enums 1910 1911Enable optimizations based on the strict definition of an enum's value range 1912 1913.. option:: -fstrict-float-cast-overflow, -fno-strict-float-cast-overflow 1914 1915Assume that overflowing float-to-int casts are undefined (default) 1916 1917.. option:: -fstrict-overflow, -fno-strict-overflow 1918 1919.. option:: -fstrict-return, -fno-strict-return 1920 1921Always treat control flow paths that fall off the end of a non-void function as unreachable 1922 1923.. option:: -fstrict-vtable-pointers, -fno-strict-vtable-pointers 1924 1925Enable optimizations based on the strict rules for overwriting polymorphic C++ objects 1926 1927.. option:: -fstruct-path-tbaa, -fno-struct-path-tbaa 1928 1929.. option:: -ftabstop=<arg> 1930 1931.. option:: -ftemplate-backtrace-limit=<arg> 1932 1933.. option:: -ftemplate-depth-<arg> 1934 1935.. option:: -ftemplate-depth=<arg> 1936 1937.. option:: -ftest-coverage 1938 1939.. option:: -fthinlto-index=<arg> 1940 1941Perform ThinLTO importing using provided function summary index 1942 1943.. option:: -fthreadsafe-statics, -fno-threadsafe-statics 1944 1945.. option:: -ftime-report 1946 1947.. option:: -ftime-trace 1948 1949Turn on time profiler. Results can be analyzed with chrome://tracing or 1950`Speedscope App <https://www.speedscope.app>`_ for flamegraph visualization 1951 1952.. option:: -ftime-trace-granularity=<arg> 1953 1954Minimum time granularity (in microseconds) traced by time profiler 1955 1956.. option:: -ftls-model=<arg> 1957 1958.. option:: -ftrap-function=<arg> 1959 1960Issue call to specified function rather than a trap instruction 1961 1962.. option:: -ftrapping-math, -fno-trapping-math 1963 1964.. option:: -ftrapv 1965 1966Trap on integer overflow 1967 1968.. option:: -ftrapv-handler <arg> 1969 1970.. program:: clang1 1971.. option:: -ftrapv-handler=<function name> 1972.. program:: clang 1973 1974Specify the function to be called on overflow 1975 1976.. option:: -ftrigraphs, -fno-trigraphs, -trigraphs, --trigraphs 1977 1978Process trigraph sequences 1979 1980.. option:: -funique-section-names, -fno-unique-section-names 1981 1982Use unique names for text and data sections (ELF Only) 1983 1984.. option:: -funit-at-a-time, -fno-unit-at-a-time 1985 1986.. option:: -funroll-loops, -fno-unroll-loops 1987 1988Turn on loop unroller 1989 1990.. option:: -funsafe-math-optimizations, -fno-unsafe-math-optimizations 1991 1992.. option:: -funsigned-bitfields 1993 1994.. option:: -funsigned-char, -fno-unsigned-char, --unsigned-char 1995 1996.. option:: -funwind-tables, -fno-unwind-tables 1997 1998.. option:: -fuse-cxa-atexit, -fno-use-cxa-atexit 1999 2000.. option:: -fuse-init-array, -fno-use-init-array 2001 2002Use .init\_array instead of .ctors 2003 2004.. option:: -fuse-ld=<arg> 2005 2006.. option:: -fuse-line-directives, -fno-use-line-directives 2007 2008.. option:: -fveclib=<arg> 2009 2010Use the given vector functions library 2011 2012.. option:: -fvectorize, -fno-vectorize, -ftree-vectorize 2013 2014Enable the loop vectorization passes 2015 2016.. option:: -fverbose-asm, -fno-verbose-asm, -dA 2017 2018.. option:: -fvisibility-inlines-hidden 2019 2020Give inline C++ member functions hidden visibility by default 2021 2022.. option:: -fvisibility-ms-compat 2023 2024Give global types 'default' visibility and global functions and variables 'hidden' visibility by default 2025 2026.. option:: -fvisibility=<arg> 2027 2028Set the default symbol visibility for all global declarations 2029 2030.. option:: -fwhole-program-vtables, -fno-whole-program-vtables 2031 2032Enables whole-program vtable optimization. Requires -flto 2033 2034.. option:: -fwrapv, -fno-wrapv 2035 2036Treat signed integer overflow as two's complement 2037 2038.. option:: -fwritable-strings 2039 2040Store string literals as writable data 2041 2042.. option:: -fxray-always-emit-customevents, -fno-xray-always-emit-customevents 2043 2044Determine whether to always emit \_\_xray\_customevent(...) calls even if the function it appears in is not always instrumented. 2045 2046.. option:: -fxray-always-emit-typedevents, -fno-xray-always-emit-typedevents 2047 2048Determine whether to always emit \_\_xray\_typedevent(...) calls even if the function it appears in is not always instrumented. 2049 2050.. option:: -fxray-always-instrument=<arg> 2051 2052DEPRECATED: Filename defining the whitelist for imbuing the 'always instrument' XRay attribute. 2053 2054.. option:: -fxray-attr-list=<arg> 2055 2056Filename defining the list of functions/types for imbuing XRay attributes. 2057 2058.. option:: -fxray-instruction-threshold<arg> 2059 2060.. program:: clang1 2061.. option:: -fxray-instruction-threshold=<arg> 2062.. program:: clang 2063 2064Sets the minimum function size to instrument with XRay 2065 2066.. option:: -fxray-instrument, -fno-xray-instrument 2067 2068Generate XRay instrumentation sleds on function entry and exit 2069 2070.. option:: -fxray-instrumentation-bundle=<arg> 2071 2072Select which XRay instrumentation points to emit. Options: all, none, function, custom. Default is 'all'. 2073 2074.. option:: -fxray-link-deps 2075 2076Tells clang to add the link dependencies for XRay. 2077 2078.. option:: -fxray-modes=<arg> 2079 2080List of modes to link in by default into XRay instrumented binaries. 2081 2082.. option:: -fxray-never-instrument=<arg> 2083 2084DEPRECATED: Filename defining the whitelist for imbuing the 'never instrument' XRay attribute. 2085 2086.. option:: -fzero-initialized-in-bss, -fno-zero-initialized-in-bss 2087 2088.. option:: -fzvector, -fno-zvector, -mzvector 2089 2090Enable System z vector language extension 2091 2092.. option:: -pedantic, --pedantic, -no-pedantic, --no-pedantic 2093 2094.. option:: -pedantic-errors, --pedantic-errors 2095 2096OpenCL flags 2097------------ 2098.. option:: -cl-denorms-are-zero 2099 2100OpenCL only. Allow denormals to be flushed to zero. 2101 2102.. option:: -cl-fast-relaxed-math 2103 2104OpenCL only. Sets -cl-finite-math-only and -cl-unsafe-math-optimizations, and defines \_\_FAST\_RELAXED\_MATH\_\_. 2105 2106.. option:: -cl-finite-math-only 2107 2108OpenCL only. Allow floating-point optimizations that assume arguments and results are not NaNs or +-Inf. 2109 2110.. option:: -cl-fp32-correctly-rounded-divide-sqrt 2111 2112OpenCL only. Specify that single precision floating-point divide and sqrt used in the program source are correctly rounded. 2113 2114.. option:: -cl-kernel-arg-info 2115 2116OpenCL only. Generate kernel argument metadata. 2117 2118.. option:: -cl-mad-enable 2119 2120OpenCL only. Allow use of less precise MAD computations in the generated binary. 2121 2122.. option:: -cl-no-signed-zeros 2123 2124OpenCL only. Allow use of less precise no signed zeros computations in the generated binary. 2125 2126.. option:: -cl-opt-disable 2127 2128OpenCL only. This option disables all optimizations. By default optimizations are enabled. 2129 2130.. option:: -cl-single-precision-constant 2131 2132OpenCL only. Treat double precision floating-point constant as single precision constant. 2133 2134.. option:: -cl-std=<arg> 2135 2136OpenCL language standard to compile for. 2137 2138.. option:: -cl-strict-aliasing 2139 2140OpenCL only. This option is added for compatibility with OpenCL 1.0. 2141 2142.. option:: -cl-uniform-work-group-size 2143 2144OpenCL only. Defines that the global work-size be a multiple of the work-group size specified to clEnqueueNDRangeKernel 2145 2146.. option:: -cl-unsafe-math-optimizations 2147 2148OpenCL only. Allow unsafe floating-point optimizations. Also implies -cl-no-signed-zeros and -cl-mad-enable. 2149 2150Target-dependent compilation options 2151~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2152.. option:: -G<size>, -G=<arg>, -msmall-data-threshold=<arg> 2153 2154Put objects of at most <size> bytes into small data section (MIPS / Hexagon) 2155 2156.. option:: -m16 2157 2158.. option:: -m32 2159 2160.. option:: -m64 2161 2162.. option:: -mabi=<arg> 2163 2164.. option:: -malign-double 2165 2166Align doubles to two words in structs (x86 only) 2167 2168.. option:: -march=<arg> 2169 2170.. option:: -masm=<arg> 2171 2172.. option:: -mbackchain, -mno-backchain 2173 2174Link stack frames through backchain on System Z 2175 2176.. option:: -mcmodel=<arg> 2177 2178.. option:: -mconsole<arg> 2179 2180.. 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) 2181 2182Use -mcpu=? to see a list of supported cpu models. 2183 2184.. option:: -mcrc, -mno-crc 2185 2186Allow use of CRC instructions (ARM/Mips only) 2187 2188.. option:: -mdefault-build-attributes<arg>, -mno-default-build-attributes<arg> 2189 2190.. option:: -mdll<arg> 2191 2192.. option:: -mdynamic-no-pic<arg> 2193 2194.. option:: -meabi <arg> 2195 2196Set EABI type, e.g. 4, 5 or gnu (default depends on triple) 2197 2198.. option:: -mfentry 2199 2200Insert calls to fentry at function entry (x86/SystemZ only) 2201 2202.. option:: -mfloat-abi=<arg> 2203 2204.. option:: -mfpmath=<arg> 2205 2206.. option:: -mfpu=<arg> 2207 2208.. option:: -mglobal-merge, -mno-global-merge 2209 2210Enable merging of globals 2211 2212.. option:: -mhard-float 2213 2214.. option:: -mhwdiv=<arg>, --mhwdiv <arg>, --mhwdiv=<arg> 2215 2216.. option:: -miamcu, -mno-iamcu 2217 2218Use Intel MCU ABI 2219 2220.. option:: -mimplicit-float, -mno-implicit-float 2221 2222.. option:: -mimplicit-it=<arg> 2223 2224.. option:: -mincremental-linker-compatible, -mno-incremental-linker-compatible 2225 2226(integrated-as) Emit an object file which can be used with an incremental linker 2227 2228.. option:: -miphoneos-version-min=<arg>, -mios-version-min=<arg> 2229 2230.. option:: -mkernel 2231 2232.. option:: -mlong-calls, -mno-long-calls 2233 2234Generate branches with extended addressability, usually via indirect jumps. 2235 2236.. option:: -mmacosx-version-min=<arg>, -mmacos-version-min=<arg> 2237 2238Set macOS deployment target 2239 2240.. option:: -mmcu=<arg> 2241 2242.. option:: -mms-bitfields, -mno-ms-bitfields 2243 2244Set the default structure layout to be compatible with the Microsoft compiler standard 2245 2246.. option:: -momit-leaf-frame-pointer, -mno-omit-leaf-frame-pointer 2247 2248Omit frame pointer setup for leaf functions 2249 2250.. option:: -moslib=<arg> 2251 2252.. option:: -mpie-copy-relocations, -mno-pie-copy-relocations 2253 2254Use copy relocations support for PIE builds 2255 2256.. option:: -mprefer-vector-width=<arg> 2257 2258Specifies preferred vector width for auto-vectorization. Defaults to 'none' which allows target specific decisions. 2259 2260.. option:: -mqdsp6-compat 2261 2262Enable hexagon-qdsp6 backward compatibility 2263 2264.. option:: -mrecip 2265 2266.. program:: clang1 2267.. option:: -mrecip=<arg1>,<arg2>... 2268.. program:: clang 2269 2270.. option:: -mred-zone, -mno-red-zone 2271 2272.. option:: -mregparm=<arg> 2273 2274.. option:: -mrelax-all, -mno-relax-all 2275 2276(integrated-as) Relax all machine instructions 2277 2278.. option:: -mretpoline, -mno-retpoline 2279 2280.. option:: -mrtd, -mno-rtd 2281 2282Make StdCall calling convention the default 2283 2284.. option:: -msign-return-address=<arg> 2285 2286Select return address signing scope 2287 2288.. option:: -msoft-float, -mno-soft-float 2289 2290Use software floating point 2291 2292.. option:: -mstack-alignment=<arg> 2293 2294Set the stack alignment 2295 2296.. option:: -mstack-arg-probe, -mno-stack-arg-probe 2297 2298Enable stack probes 2299 2300.. option:: -mstack-probe-size=<arg> 2301 2302Set the stack probe size 2303 2304.. option:: -mstackrealign, -mno-stackrealign 2305 2306Force realign the stack at entry to every function 2307 2308.. option:: -mthread-model <arg> 2309 2310The thread model to use, e.g. posix, single (posix by default) 2311 2312.. option:: -mthreads<arg> 2313 2314.. option:: -mthumb, -mno-thumb 2315 2316.. option:: -mtune=<arg> 2317 2318Use -mtune=? to see a list of supported cpu models. 2319 2320.. option:: -mtvos-version-min=<arg>, -mappletvos-version-min=<arg> 2321 2322.. option:: -municode<arg> 2323 2324.. option:: -mvx, -mno-vx 2325 2326.. option:: -mwarn-nonportable-cfstrings, -mno-warn-nonportable-cfstrings 2327 2328.. option:: -mwatchos-version-min=<arg> 2329 2330.. option:: -mwindows<arg> 2331 2332.. option:: -mx32 2333 2334AARCH64 2335------- 2336.. option:: -ffixed-x1 2337 2338Reserve the x1 register (AArch64 only) 2339 2340.. option:: -ffixed-x2 2341 2342Reserve the x2 register (AArch64 only) 2343 2344.. option:: -ffixed-x3 2345 2346Reserve the x3 register (AArch64 only) 2347 2348.. option:: -ffixed-x4 2349 2350Reserve the x4 register (AArch64 only) 2351 2352.. option:: -ffixed-x5 2353 2354Reserve the x5 register (AArch64 only) 2355 2356.. option:: -ffixed-x6 2357 2358Reserve the x6 register (AArch64 only) 2359 2360.. option:: -ffixed-x7 2361 2362Reserve the x7 register (AArch64 only) 2363 2364.. option:: -ffixed-x18 2365 2366Reserve the x18 register (AArch64 only) 2367 2368.. option:: -ffixed-x20 2369 2370Reserve the x20 register (AArch64 only) 2371 2372.. option:: -fcall-saved-x8 2373 2374Make the x8 register call-saved (AArch64 only) 2375 2376.. option:: -fcall-saved-x9 2377 2378Make the x9 register call-saved (AArch64 only) 2379 2380.. option:: -fcall-saved-x10 2381 2382Make the x10 register call-saved (AArch64 only) 2383 2384.. option:: -fcall-saved-x11 2385 2386Make the x11 register call-saved (AArch64 only) 2387 2388.. option:: -fcall-saved-x12 2389 2390Make the x12 register call-saved (AArch64 only) 2391 2392.. option:: -fcall-saved-x13 2393 2394Make the x13 register call-saved (AArch64 only) 2395 2396.. option:: -fcall-saved-x14 2397 2398Make the x14 register call-saved (AArch64 only) 2399 2400.. option:: -fcall-saved-x15 2401 2402Make the x15 register call-saved (AArch64 only) 2403 2404.. option:: -fcall-saved-x18 2405 2406Make the x18 register call-saved (AArch64 only) 2407 2408.. option:: -mfix-cortex-a53-835769, -mno-fix-cortex-a53-835769 2409 2410Workaround Cortex-A53 erratum 835769 (AArch64 only) 2411 2412.. option:: -mgeneral-regs-only 2413 2414Generate code which only uses the general purpose registers (AArch64 only) 2415 2416AMDGPU 2417------ 2418.. option:: -mcumode, -mno-cumode 2419 2420CU wavefront execution mode is used if enabled and WGP wavefront execution mode 2421is used if disabled (AMDGPU only) 2422 2423.. option:: -mwavefrontsize64, -mno-wavefrontsize64 2424 2425Wavefront size 64 is used if enabled and wavefront size 32 if disabled (AMDGPU only) 2426 2427.. option:: -mxnack, -mno-xnack 2428 2429Enable XNACK (AMDGPU only) 2430 2431ARM 2432--- 2433 2434.. option:: -ffixed-r6 2435 2436Reserve the r6 register (ARM only) 2437 2438.. option:: -ffixed-r7 2439 2440Reserve the r7 register (ARM only) 2441 2442.. option:: -ffixed-r8 2443 2444Reserve the r8 register (ARM only) 2445 2446.. option:: -ffixed-r9 2447 2448Reserve the r9 register (ARM only) 2449 2450.. option:: -ffixed-r10 2451 2452Reserve the r10 register (ARM only) 2453 2454.. option:: -ffixed-r11 2455 2456Reserve the r11 register (ARM only) 2457 2458.. option:: -mexecute-only, -mno-execute-only, -mpure-code 2459 2460Disallow generation of data access to code sections (ARM only) 2461 2462.. option:: -mno-movt 2463 2464Disallow use of movt/movw pairs (ARM only) 2465 2466.. option:: -mno-neg-immediates 2467 2468Disallow converting instructions with negative immediates to their negation or inversion. 2469 2470.. option:: -mnocrc 2471 2472Disallow use of CRC instructions (ARM only) 2473 2474.. option:: -mrestrict-it, -mno-restrict-it 2475 2476Disallow generation of deprecated IT blocks for ARMv8. It is on by default for ARMv8 Thumb mode. 2477 2478.. option:: -mtp=<arg> 2479 2480Read thread pointer from coprocessor register (ARM only) 2481 2482.. option:: -munaligned-access, -mno-unaligned-access 2483 2484Allow memory accesses to be unaligned (AArch32/AArch64 only) 2485 2486Hexagon 2487------- 2488.. option:: -mieee-rnd-near 2489 2490.. option:: -mmemops, -mno-memops 2491 2492Enable generation of memop instructions 2493 2494.. option:: -mnvj, -mno-nvj 2495 2496Enable generation of new-value jumps 2497 2498.. option:: -mnvs, -mno-nvs 2499 2500Enable generation of new-value stores 2501 2502.. option:: -mpackets, -mno-packets 2503 2504Enable generation of instruction packets 2505 2506Hexagon 2507------- 2508.. option:: -mhvx, -mno-hvx 2509 2510Enable Hexagon Vector eXtensions 2511 2512.. option:: -mhvx-length=<arg> 2513 2514Set Hexagon Vector Length 2515 2516.. program:: clang1 2517.. option:: -mhvx=<arg> 2518.. program:: clang 2519 2520Enable Hexagon Vector eXtensions 2521 2522MIPS 2523---- 2524.. option:: -mabicalls, -mno-abicalls 2525 2526Enable SVR4-style position-independent code (Mips only) 2527 2528.. option:: -mabs=<arg> 2529 2530.. option:: -mcheck-zero-division, -mno-check-zero-division 2531 2532.. option:: -mcompact-branches=<arg> 2533 2534.. option:: -mdouble-float 2535 2536.. option:: -mdsp, -mno-dsp 2537 2538.. option:: -mdspr2, -mno-dspr2 2539 2540.. option:: -membedded-data, -mno-embedded-data 2541 2542Place constants in the .rodata section instead of the .sdata section even if they meet the -G <size> threshold (MIPS) 2543 2544.. option:: -mextern-sdata, -mno-extern-sdata 2545 2546Assume that externally defined data is in the small data if it meets the -G <size> threshold (MIPS) 2547 2548.. option:: -mfp32 2549 2550Use 32-bit floating point registers (MIPS only) 2551 2552.. option:: -mfp64 2553 2554Use 64-bit floating point registers (MIPS only) 2555 2556.. option:: -mginv, -mno-ginv 2557 2558.. option:: -mgpopt, -mno-gpopt 2559 2560Use GP relative accesses for symbols known to be in a small data section (MIPS) 2561 2562.. option:: -mindirect-jump=<arg> 2563 2564Change indirect jump instructions to inhibit speculation 2565 2566.. option:: -mips16 2567 2568.. option:: -mldc1-sdc1, -mno-ldc1-sdc1 2569 2570.. option:: -mlocal-sdata, -mno-local-sdata 2571 2572Extend the -G behaviour to object local data (MIPS) 2573 2574.. option:: -mmadd4, -mno-madd4 2575 2576Enable the generation of 4-operand madd.s, madd.d and related instructions. 2577 2578.. option:: -mmicromips, -mno-micromips 2579 2580.. option:: -mmsa, -mno-msa 2581 2582Enable MSA ASE (MIPS only) 2583 2584.. option:: -mmt, -mno-mt 2585 2586Enable MT ASE (MIPS only) 2587 2588.. option:: -mnan=<arg> 2589 2590.. option:: -mno-mips16 2591 2592.. option:: -msingle-float 2593 2594.. option:: -mvirt, -mno-virt 2595 2596.. option:: -mxgot, -mno-xgot 2597 2598PowerPC 2599------- 2600.. option:: -maltivec, -mno-altivec 2601 2602.. option:: -mcmpb, -mno-cmpb 2603 2604.. option:: -mcrbits, -mno-crbits 2605 2606.. option:: -mcrypto, -mno-crypto 2607 2608.. option:: -mdirect-move, -mno-direct-move 2609 2610.. option:: -mfloat128, -mno-float128 2611 2612.. option:: -mfprnd, -mno-fprnd 2613 2614.. option:: -mhtm, -mno-htm 2615 2616.. option:: -minvariant-function-descriptors, -mno-invariant-function-descriptors 2617 2618.. option:: -misel, -mno-isel 2619 2620.. option:: -mlongcall, -mno-longcall 2621 2622.. option:: -mmfocrf, -mmfcrf, -mno-mfocrf 2623 2624.. option:: -mpopcntd, -mno-popcntd 2625 2626.. option:: -mpower8-vector, -mno-power8-vector 2627 2628.. option:: -mpower9-vector, -mno-power9-vector 2629 2630.. option:: -mqpx, -mno-qpx 2631 2632.. option:: -msecure-plt 2633 2634.. option:: -mvsx, -mno-vsx 2635 2636WebAssembly 2637----------- 2638.. option:: -mexception-handling, -mno-exception-handling 2639 2640.. option:: -mnontrapping-fptoint, -mno-nontrapping-fptoint 2641 2642.. option:: -msign-ext, -mno-sign-ext 2643 2644.. option:: -msimd128, -mno-simd128 2645 2646X86 2647--- 2648.. option:: -m3dnow, -mno-3dnow 2649 2650.. option:: -m3dnowa, -mno-3dnowa 2651 2652.. option:: -madx, -mno-adx 2653 2654.. option:: -maes, -mno-aes 2655 2656.. option:: -mavx, -mno-avx 2657 2658.. option:: -mavx2, -mno-avx2 2659 2660.. option:: -mavx512bitalg, -mno-avx512bitalg 2661 2662.. option:: -mavx512bf16, -mno-avx512bf16 2663 2664.. option:: -mavx512bw, -mno-avx512bw 2665 2666.. option:: -mavx512cd, -mno-avx512cd 2667 2668.. option:: -mavx512dq, -mno-avx512dq 2669 2670.. option:: -mavx512er, -mno-avx512er 2671 2672.. option:: -mavx512f, -mno-avx512f 2673 2674.. option:: -mavx512ifma, -mno-avx512ifma 2675 2676.. option:: -mavx512pf, -mno-avx512pf 2677 2678.. option:: -mavx512vbmi, -mno-avx512vbmi 2679 2680.. option:: -mavx512vbmi2, -mno-avx512vbmi2 2681 2682.. option:: -mavx512vl, -mno-avx512vl 2683 2684.. option:: -mavx512vnni, -mno-avx512vnni 2685 2686.. option:: -mavx512vp2intersect, -mno-avx512vp2intersect 2687 2688.. option:: -mavx512vpopcntdq, -mno-avx512vpopcntdq 2689 2690.. option:: -mbmi, -mno-bmi 2691 2692.. option:: -mbmi2, -mno-bmi2 2693 2694.. option:: -mcldemote, -mno-cldemote 2695 2696.. option:: -mclflushopt, -mno-clflushopt 2697 2698.. option:: -mclwb, -mno-clwb 2699 2700.. option:: -mclzero, -mno-clzero 2701 2702.. option:: -mcx16, -mno-cx16 2703 2704.. option:: -menqcmd, -mno-enqcmd 2705 2706.. option:: -mf16c, -mno-f16c 2707 2708.. option:: -mfma, -mno-fma 2709 2710.. option:: -mfma4, -mno-fma4 2711 2712.. option:: -mfsgsbase, -mno-fsgsbase 2713 2714.. option:: -mfxsr, -mno-fxsr 2715 2716.. option:: -mgfni, -mno-gfni 2717 2718.. option:: -minvpcid, -mno-invpcid 2719 2720.. option:: -mlwp, -mno-lwp 2721 2722.. option:: -mlzcnt, -mno-lzcnt 2723 2724.. option:: -mmmx, -mno-mmx 2725 2726.. option:: -mmovbe, -mno-movbe 2727 2728.. option:: -mmovdir64b, -mno-movdir64b 2729 2730.. option:: -mmovdiri, -mno-movdiri 2731 2732.. option:: -mmpx, -mno-mpx 2733 2734.. option:: -mmwaitx, -mno-mwaitx 2735 2736.. option:: -mpclmul, -mno-pclmul 2737 2738.. option:: -mpconfig, -mno-pconfig 2739 2740.. option:: -mpku, -mno-pku 2741 2742.. option:: -mpopcnt, -mno-popcnt 2743 2744.. option:: -mprefetchwt1, -mno-prefetchwt1 2745 2746.. option:: -mprfchw, -mno-prfchw 2747 2748.. option:: -mptwrite, -mno-ptwrite 2749 2750.. option:: -mrdpid, -mno-rdpid 2751 2752.. option:: -mrdrnd, -mno-rdrnd 2753 2754.. option:: -mrdseed, -mno-rdseed 2755 2756.. option:: -mretpoline-external-thunk, -mno-retpoline-external-thunk 2757 2758.. option:: -mrtm, -mno-rtm 2759 2760.. option:: -msahf, -mno-sahf 2761 2762.. option:: -msgx, -mno-sgx 2763 2764.. option:: -msha, -mno-sha 2765 2766.. option:: -mshstk, -mno-shstk 2767 2768.. option:: -msse, -mno-sse 2769 2770.. option:: -msse2, -mno-sse2 2771 2772.. option:: -msse3, -mno-sse3 2773 2774.. option:: -msse4.1, -mno-sse4.1 2775 2776.. program:: clang1 2777.. option:: -msse4.2, -mno-sse4.2, -msse4 2778.. program:: clang 2779 2780.. option:: -msse4a, -mno-sse4a 2781 2782.. option:: -mssse3, -mno-ssse3 2783 2784.. option:: -mtbm, -mno-tbm 2785 2786.. option:: -mvaes, -mno-vaes 2787 2788.. option:: -mvpclmulqdq, -mno-vpclmulqdq 2789 2790.. option:: -mwaitpkg, -mno-waitpkg 2791 2792.. option:: -mwbnoinvd, -mno-wbnoinvd 2793 2794.. option:: -mx87, -m80387, -mno-x87 2795 2796.. option:: -mxop, -mno-xop 2797 2798.. option:: -mxsave, -mno-xsave 2799 2800.. option:: -mxsavec, -mno-xsavec 2801 2802.. option:: -mxsaveopt, -mno-xsaveopt 2803 2804.. option:: -mxsaves, -mno-xsaves 2805 2806RISCV 2807----- 2808.. option:: -mrelax, -mno-relax 2809 2810Enable linker relaxation 2811 2812Optimization level 2813~~~~~~~~~~~~~~~~~~ 2814 2815Flags controlling how much optimization should be performed. 2816 2817.. option:: -O<arg>, -O (equivalent to -O2), --optimize, --optimize=<arg> 2818 2819.. option:: -Ofast<arg> 2820 2821Debug information generation 2822~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2823 2824Flags controlling how much and what kind of debug information should be 2825generated. 2826 2827Kind and level of debug information 2828----------------------------------- 2829.. option:: -g, --debug, --debug=<arg> 2830 2831Generate source-level debug information 2832 2833.. option:: -gdwarf-2 2834 2835Generate source-level debug information with dwarf version 2 2836 2837.. option:: -gdwarf-3 2838 2839Generate source-level debug information with dwarf version 3 2840 2841.. option:: -gdwarf-4, -gdwarf 2842 2843Generate source-level debug information with dwarf version 4 2844 2845.. option:: -gdwarf-5 2846 2847Generate source-level debug information with dwarf version 5 2848 2849.. option:: -gfull 2850 2851.. option:: -gused 2852 2853Debug level 2854___________ 2855.. option:: -g0 2856 2857.. option:: -g2 2858 2859.. option:: -g3 2860 2861.. option:: -ggdb0 2862 2863.. option:: -ggdb1 2864 2865.. option:: -ggdb2 2866 2867.. option:: -ggdb3 2868 2869.. option:: -gline-tables-only, -g1, -gmlt 2870 2871Emit debug line number tables only 2872 2873.. option:: -gmodules 2874 2875Generate debug info with external references to clang modules or precompiled headers 2876 2877Debugger to tune debug information for 2878______________________________________ 2879.. option:: -ggdb 2880 2881.. option:: -glldb 2882 2883.. option:: -gsce 2884 2885Debug information flags 2886----------------------- 2887.. option:: -gcolumn-info, -gno-column-info 2888 2889.. option:: -gdwarf-aranges 2890 2891.. option:: -gembed-source, -gno-embed-source 2892 2893Embed source text in DWARF debug sections 2894 2895.. option:: -ggnu-pubnames, -gno-gnu-pubnames 2896 2897.. option:: -gpubnames, -gno-pubnames 2898 2899.. option:: -grecord-command-line, -grecord-gcc-switches, -gno-record-command-line, -gno-record-gcc-switches 2900 2901.. option:: -gsplit-dwarf 2902 2903.. option:: -gstrict-dwarf, -gno-strict-dwarf 2904 2905.. option:: -gz 2906 2907DWARF debug sections compression type 2908 2909.. program:: clang1 2910.. option:: -gz=<arg> 2911.. program:: clang 2912 2913DWARF debug sections compression type 2914 2915Static analyzer flags 2916===================== 2917 2918Flags controlling the behavior of the Clang Static Analyzer. 2919 2920.. option:: -Xanalyzer <arg> 2921 2922Pass <arg> to the static analyzer 2923 2924Fortran compilation flags 2925========================= 2926 2927Flags that will be passed onto the ``gfortran`` compiler when Clang is given 2928a Fortran input. 2929 2930.. option:: -A<arg>, --assert <arg>, --assert=<arg> 2931 2932.. option:: -A-<arg> 2933 2934.. option:: -J<arg> 2935 2936.. option:: -cpp 2937 2938.. option:: -faggressive-function-elimination, -fno-aggressive-function-elimination 2939 2940.. option:: -falign-commons, -fno-align-commons 2941 2942.. option:: -fall-intrinsics, -fno-all-intrinsics 2943 2944.. option:: -fautomatic, -fno-automatic 2945 2946.. option:: -fbackslash, -fno-backslash 2947 2948.. option:: -fbacktrace, -fno-backtrace 2949 2950.. option:: -fblas-matmul-limit=<arg> 2951 2952.. option:: -fbounds-check, -fno-bounds-check 2953 2954.. option:: -fcheck-array-temporaries, -fno-check-array-temporaries 2955 2956.. option:: -fcheck=<arg> 2957 2958.. option:: -fcoarray=<arg> 2959 2960.. option:: -fconvert=<arg> 2961 2962.. option:: -fcray-pointer, -fno-cray-pointer 2963 2964.. option:: -fd-lines-as-code, -fno-d-lines-as-code 2965 2966.. option:: -fd-lines-as-comments, -fno-d-lines-as-comments 2967 2968.. option:: -fdefault-double-8, -fno-default-double-8 2969 2970.. option:: -fdefault-integer-8, -fno-default-integer-8 2971 2972.. option:: -fdefault-real-8, -fno-default-real-8 2973 2974.. option:: -fdollar-ok, -fno-dollar-ok 2975 2976.. option:: -fdump-fortran-optimized, -fno-dump-fortran-optimized 2977 2978.. option:: -fdump-fortran-original, -fno-dump-fortran-original 2979 2980.. option:: -fdump-parse-tree, -fno-dump-parse-tree 2981 2982.. option:: -fexternal-blas, -fno-external-blas 2983 2984.. option:: -ff2c, -fno-f2c 2985 2986.. option:: -ffixed-form, -fno-fixed-form 2987 2988.. option:: -ffixed-line-length-<arg> 2989 2990.. option:: -ffpe-trap=<arg> 2991 2992.. option:: -ffree-form, -fno-free-form 2993 2994.. option:: -ffree-line-length-<arg> 2995 2996.. option:: -ffrontend-optimize, -fno-frontend-optimize 2997 2998.. option:: -fimplicit-none, -fno-implicit-none 2999 3000.. option:: -finit-character=<arg> 3001 3002.. option:: -finit-integer=<arg> 3003 3004.. option:: -finit-local-zero, -fno-init-local-zero 3005 3006.. option:: -finit-logical=<arg> 3007 3008.. option:: -finit-real=<arg> 3009 3010.. option:: -finteger-4-integer-8, -fno-integer-4-integer-8 3011 3012.. option:: -fintrinsic-modules-path, -fno-intrinsic-modules-path 3013 3014.. option:: -fmax-array-constructor=<arg> 3015 3016.. option:: -fmax-errors=<arg> 3017 3018.. option:: -fmax-identifier-length, -fno-max-identifier-length 3019 3020.. option:: -fmax-stack-var-size=<arg> 3021 3022.. option:: -fmax-subrecord-length=<arg> 3023 3024.. option:: -fmodule-private, -fno-module-private 3025 3026.. option:: -fpack-derived, -fno-pack-derived 3027 3028.. option:: -fprotect-parens, -fno-protect-parens 3029 3030.. option:: -frange-check, -fno-range-check 3031 3032.. option:: -freal-4-real-10, -fno-real-4-real-10 3033 3034.. option:: -freal-4-real-16, -fno-real-4-real-16 3035 3036.. option:: -freal-4-real-8, -fno-real-4-real-8 3037 3038.. option:: -freal-8-real-10, -fno-real-8-real-10 3039 3040.. option:: -freal-8-real-16, -fno-real-8-real-16 3041 3042.. option:: -freal-8-real-4, -fno-real-8-real-4 3043 3044.. option:: -frealloc-lhs, -fno-realloc-lhs 3045 3046.. option:: -frecord-marker=<arg> 3047 3048.. option:: -frecursive, -fno-recursive 3049 3050.. option:: -frepack-arrays, -fno-repack-arrays 3051 3052.. option:: -fsecond-underscore, -fno-second-underscore 3053 3054.. option:: -fsign-zero, -fno-sign-zero 3055 3056.. option:: -fstack-arrays, -fno-stack-arrays 3057 3058.. option:: -funderscoring, -fno-underscoring 3059 3060.. option:: -fwhole-file, -fno-whole-file 3061 3062.. option:: -imultilib <arg> 3063 3064.. option:: -nocpp 3065 3066.. option:: -static-libgfortran 3067 3068Linker flags 3069============ 3070Flags that are passed on to the linker 3071 3072.. option:: -L<dir>, --library-directory <arg>, --library-directory=<arg> 3073 3074Add directory to library search path 3075 3076.. option:: -Mach 3077 3078.. option:: -T<script> 3079 3080Specify <script> as linker script 3081 3082.. option:: -Tbss<addr> 3083 3084Set starting address of BSS to <addr> 3085 3086.. option:: -Tdata<addr> 3087 3088Set starting address of DATA to <addr> 3089 3090.. option:: -Ttext<addr> 3091 3092Set starting address of TEXT to <addr> 3093 3094.. option:: -Wl,<arg>,<arg2>... 3095 3096Pass the comma separated arguments in <arg> to the linker 3097 3098.. option:: -X 3099 3100.. option:: -Xlinker <arg>, --for-linker <arg>, --for-linker=<arg> 3101 3102Pass <arg> to the linker 3103 3104.. program:: clang1 3105.. option:: -Z 3106.. program:: clang 3107 3108.. option:: -e<arg>, --entry 3109 3110.. option:: -filelist <arg> 3111 3112.. option:: --hip-device-lib-path=<arg> 3113 3114HIP device library path 3115 3116.. option:: --hip-device-lib=<arg> 3117 3118HIP device library 3119 3120.. option:: -l<arg> 3121 3122.. option:: -r 3123 3124.. option:: -rpath <arg> 3125 3126.. option:: -s 3127 3128.. option:: -t 3129 3130.. option:: -u<arg>, --force-link <arg>, --force-link=<arg> 3131 3132.. option:: -undef 3133 3134undef all system defines 3135 3136.. option:: -undefined<arg>, --no-undefined 3137 3138.. option:: -z <arg> 3139 3140Pass -z <arg> to the linker 3141 3142