$ gcc --help -v -vオプション追加で呼び出される各プロセスごとに--helpによる出力が発生 Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/8.2.0/lto-wrapper Usage: gcc [options] file... 以下、gccのコマンドラインオプションの説明 Options: -pass-exit-codes Exit with highest error code from a phase. --help Display this information. --target-help Display target specific command line options. --help={common|optimizers|params|target|warnings|[^]{joined|separate|undocumented}}[,...]. ︙ -pie Create a dynamically linked position independent executable. -shared Create a shared library. -x <language> Specify the language of the following input files. Permissible languages include: c c++ assembler none 'none' means revert to the default behavior of guessing the language based on the file's extension. Options starting with -g, -f, -m, -O, -W, or --param are automatically passed on to the various sub-processes invoked by gcc. In order to pass other options on to these processes the -W<letter> options must be used. Target: x86_64-pc-linux-gnu Configured with: ../configure --prefix=/usr --enable-languages=c,c++ --disable-multilib --disable-bootstrap --disable-libmpx --with-system-zlib Thread model: posix gcc version 8.2.0 (GCC) COLLECT_GCC_OPTIONS='--help' '-v' '-mtune=generic' '-march=x86-64' /usr/libexec/gcc/x86_64-pc-linux-gnu/8.2.0/cc1 -quiet -v help-dummy ... The following options are specific to just the language Ada: 以下、コンパイラのコマンドラインオプションの説明 -fbuiltin-printf Ignored. The following options are specific to just the language AdaSCIL: None found. Use --help=AdaSCIL to show *all* the options supported by the AdaSCIL front-end. The following options are specific to just the language AdaWhy: None found. Use --help=AdaWhy to show *all* the options supported by the AdaWhy front-end. The following options are specific to just the language BRIG: None found. Use --help=BRIG to show *all* the options supported by the BRIG front-end. The following options are specific to just the language C: -fgimple Enable parsing GIMPLE. -lang-asm This option lacks documentation. The following options are specific to just the language C++: -Wplacement-new Warn for placement new expressions with undefined behavior. Same as -Wplacement-new=. -Wplacement-new=<0,2> Warn for placement new expressions with undefined behavior. The following options are specific to just the language Fortran: -J<directory> Put MODULE files in 'directory'. -Waliasing Warn about possible aliasing of dummy arguments. -Walign-commons Warn about alignment of COMMON blocks. ︙ -std=f95 Conform to the ISO Fortran 95 standard. -std=gnu Conform to nothing in particular. -std=legacy Accept extensions to support legacy code. The following options are specific to just the language Go: -fgo-c-header=<file> Write Go struct definitions to file as C code. -fgo-check-divide-overflow Add explicit checks for division overflow in INT_MIN / -1. -fgo-check-divide-zero Add explicit checks for division by zero. ︙ -fgo-prefix=<string> Set package-specific prefix for exported Go names. -fgo-relative-import-path=<path> Treat a relative import as relative to path. -frequire-return-statement Functions which return values must end with return statements. The following options are specific to just the language LTO: -flinker-output= Set linker output type (used internally during LTO optimization) -fltrans Run the link-time optimizer in local transformation (LTRANS) mode. -fltrans-output-list= Specify a file to which a list of files output by LTRANS is written. -fresolution= The resolution file. -fwpa Run the link-time optimizer in whole program analysis (WPA) mode. -fwpa= Whole program analysis (WPA) mode with number of parallel jobs specified. The following options are specific to just the language ObjC: None found. Use --help=ObjC to show *all* the options supported by the ObjC front-end. The following options are specific to just the language ObjC++: -fobjc-call-cxx-cdtors Generate special Objective-C methods to initialize/destroy non-POD C++ ivars, if needed. The following options are language-related: --all-warnings Same as -Wall. Use the latter option instead. --ansi Same as -ansi. Use the latter option instead. --assert Same as -A. Use the latter option instead. ︙ -undef Do not predefine system-specific and GCC-specific macros. -v Enable verbose output. -w Suppress warnings. The --param option recognizes the following as parameters: predictable-branch-outcome Maximal estimated outcome of branch considered predictable. inline-min-speedup The minimal estimated speedup allowing inliner to ignore inline-insns-single and inline-insns-auto. max-inline-insns-single The maximum number of instructions in a single function eligible for inlining. ︙ unroll-jam-min-percent Minimum percentage of memrefs that must go away for unroll-and-jam to be considered profitable. unroll-jam-max-unroll Maximum unroll factor for the unroll-and-jam transformation. avoid-fma-max-bits Maximum number of bits for which we avoid creating FMAs. The following options control compiler warning messages: --extra-warnings Same as -Wextra. Use the latter option instead. -W This switch is deprecated; use -Wextra instead. Same as -Wextra. -Waggregate-return Warn about returning structures, unions or arrays. ︙ -Wunused-parameter Warn when a function parameter is unused. -Wunused-value Warn when an expression value is unused. -Wvector-operation-performance Warn when a vector operation is compiled outside the SIMD. The following options control optimizations: -O<number> Set optimization level to <number>. -Ofast Optimize for speed disregarding exact standards compliance. -Og Optimize for debugging experience rather than speed or size. ︙ -fweb Construct webs and split unrelated uses of single variable. -fwrapv Assume signed arithmetic overflow wraps around. -fwrapv-pointer Assume pointer overflow wraps around. The following options are target specific: -m128bit-long-double sizeof(long double) is 16. -m16 Generate 16bit i386 code. -m32 Generate 32bit i386 code. ︙ -mxsavec Support XSAVEC instructions. -mxsaveopt Support XSAVEOPT instruction. -mxsaves Support XSAVES and XRSTORS instructions. Known assembler dialects (for use with the -masm= option): att intel ︙ Known TLS dialects (for use with the -mtls-dialect= option): gnu gnu2 The following options are language-independent: --debug Same as -g. Use the latter option instead. --dumpbase Same as -dumpbase. Use the latter option instead. --dumpdir Same as -dumpdir. Use the latter option instead. ︙ -gas-loc-support Assume assembler support for (DWARF2+) .loc directives -gas-locview-support Assume assembler support for view in (DWARF2+) .loc directives -gcoff GNU C17 (GCC) version 8.2.0 (x86_64-pc-linux-gnu) compiled by GNU C version 8.2.0, GMP version 6.1.2, MPFR version 4.0.1, MPC version 1.1.0, isl version none GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Does nothing. Preserved for backward compatibility. Uses of this option are diagnosed. -gcoff1 Does nothing. Preserved for backward compatibility. Uses of this option are diagnosed. -gcoff2 Does nothing. Preserved for backward compatibility. Uses of this option are diagnosed. ︙ -pedantic-errors Like -pedantic but issue them as errors. -quiet Do not display functions compiled or elapsed time. -version Display the compiler's version. COLLECT_GCC_OPTIONS='--help' '-v' '-mtune=generic' '-march=x86-64' as -v --64 --help -o /tmp/ccmtY4m8.o /tmp/ccdw7kjU.s GNU assembler version 2.31.1 (x86_64-pc-linux-gnu) using BFD version (GNU Binutils) 2.31.1 Usage: as [option...] [asmfile...] 以下、アセンブラのコマンドラインオプションの説明 Options: -a[sub-option...] turn on listings Sub-options [default hls]: c omit false conditionals d omit debugging directives g include general info h include high-level source l include assembly m include macro expansions n omit forms processing s include symbols =FILE list to FILE (must be last sub-option) --alternate initially turn on alternate macro syntax --compress-debug-sections[={none|zlib|zlib-gnu|zlib-gabi}] compress DWARF debug sections using zlib [default] ︙ -mrelax-relocations=[no|yes] generate relax relocations -mamd64 accept only AMD64 ISA -mintel64 accept only Intel64 ISA Report bugs to <http://www.sourceware.org/bugzilla/> COMPILER_PATH=/usr/libexec/gcc/x86_64-pc-linux-gnu/8.2.0/:/usr/libexec/gcc/x86_64-pc-linux-gnu/8.2.0/:/usr/libexec/gcc/x86_64-pc-linux-gnu/:/usr/lib/gcc/x86_64-pc-linux-gnu/8.2.0/:/usr/lib/gcc/x86_64-pc-linux-gnu/ LIBRARY_PATH=/usr/lib/gcc/x86_64-pc-linux-gnu/8.2.0/:/usr/lib/gcc/x86_64-pc-linux-gnu/8.2.0/../../../../lib/:/lib/../lib/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-pc-linux-gnu/8.2.0/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='--help' '-v' '-mtune=generic' '-march=x86-64' /usr/libexec/gcc/x86_64-pc-linux-gnu/8.2.0/collect2 ... Usage: collect2 [options] 以下、リンカのコマンドラインオプションの説明 Wrap linker and generate constructor code if needed. Options: -debug Enable debug output --help Display this information -v, --version Display this program's version number Overview: http://gcc.gnu.org/onlinedocs/gccint/Collect2.html Report bugs: <https://gcc.gnu.org/bugs/> Usage: /usr/bin/ld [options] file... Options: -a KEYWORD Shared library control for HP/UX compatibility -A ARCH, --architecture ARCH Set architecture -b TARGET, --format TARGET Specify target for following input files ︙ -z dynamic-undefined-weak Make undefined weak symbols dynamic -z nodynamic-undefined-weak Do not make undefined weak symbols dynamic -z call-nop=PADDING Use PADDING as 1-byte NOP for branch Report bugs to <http://www.sourceware.org/bugzilla/> COLLECT_GCC_OPTIONS='--help' '-v' '-mtune=generic' '-march=x86-64' For bug reporting instructions, please see: <https://gcc.gnu.org/bugs/> $