MAN page from openSUSE Leap 42 gcc6-c++-6.5.0+r265524-3.1.x86_64.rpm


Section: GNU (1)
Updated: 2018-10-26


gcc - GNU project C and C++ compiler 


gcc [-c|-S|-E] [-std=standard]
    [-g] [-pg] [-Olevel]
    [-Wwarn...] [-Wpedantic]
    [-Idir...] [-Ldir...]
    [-Dmacro[=defn]...] [-Umacro]
    [-foption...] [-mmachine-option...]
    [-o outfile] [@fileinfile...

Only the most useful options are listed here; see below for theremainder. g++ accepts mostly the same options as gcc. 


When you invoke GCC, it normally does preprocessing, compilation,assembly and linking. The ``overall options'' allow you to stop thisprocess at an intermediate stage. For example, the -c optionsays not to run the linker. Then the output consists of object filesoutput by the assembler.

Other options are passed on to one or more stages of processing. Some optionscontrol the preprocessor and others the compiler itself. Yet otheroptions control the assembler and linker; most of these are notdocumented here, since you rarely need to use any of them.

Most of the command-line options that you can use with GCC are usefulfor C programs; when an option is only useful with another language(usually C++), the explanation says so explicitly. If the descriptionfor a particular option does not mention a source language, you can usethat option with all supported languages.

The usual way to run GCC is to run the executable called gcc, ormachine-gcc when cross-compiling, ormachine-gcc-version to run a specific version of GCC.When you compile C++ programs, you should invoke GCC as g++ instead.

The gcc program accepts options and file names as operands. Manyoptions have multi-letter names; therefore multiple single-letter optionsmay not be grouped: -dv is very different from -d -v.

You can mix options and other arguments. For the most part, the orderyou use doesn't matter. Order does matter when you use severaloptions of the same kind; for example, if you specify -L morethan once, the directories are searched in the order specified. Also,the placement of the -l option is significant.

Many options have long names starting with -f or with-W---for example,-fmove-loop-invariants, -Wformat and so on. Most ofthese have both positive and negative forms; the negative form of-ffoo is -fno-foo. This manual documentsonly one of these two forms, whichever one is not the default. 



Option Summary

Here is a summary of all the options, grouped by type. Explanations arein the following sections.
Overall Options
-c -S -E -o file -x language -v -### --help[=class[,...]] --target-help --version -pass-exit-codes -pipe -specs=file -wrapper @file -fplugin=file -fplugin-arg-name=arg -fdump-ada-spec[-slim] -fada-spec-parent=unit -fdump-go-spec=file
C Language Options
-ansi -std=standard -fgnu89-inline -aux-info filename -fallow-parameterless-variadic-functions -fno-asm -fno-builtin -fno-builtin-function -fhosted -ffreestanding -fopenacc -fopenmp -fopenmp-simd -fms-extensions -fplan9-extensions -fsso-struct=endianness-fallow-single-precision -fcond-mismatch -flax-vector-conversions -fsigned-bitfields -fsigned-char -funsigned-bitfields -funsigned-char -trigraphs -traditional -traditional-cpp
C++ Language Options
-fabi-version=n -fno-access-control -fcheck-new -fconstexpr-depth=n -ffriend-injection -fno-elide-constructors -fno-enforce-eh-specs -ffor-scope -fno-for-scope -fno-gnu-keywords -fno-implicit-templates -fno-implicit-inline-templates -fno-implement-inlines -fms-extensions -fno-nonansi-builtins -fnothrow-opt -fno-operator-names -fno-optional-diags -fpermissive -fno-pretty-templates -frepo -fno-rtti -fsized-deallocation -ftemplate-backtrace-limit=n -ftemplate-depth=n -fno-threadsafe-statics -fuse-cxa-atexit -fno-weak -nostdinc++ -fvisibility-inlines-hidden -fvisibility-ms-compat -fext-numeric-literals -Wabi=n -Wabi-tag -Wconversion-null -Wctor-dtor-privacy -Wdelete-non-virtual-dtor -Wliteral-suffix -Wmultiple-inheritance -Wnamespaces -Wnarrowing -Wnoexcept -Wnon-virtual-dtor -Wreorder -Weffc++ -Wstrict-null-sentinel -Wtemplates -Wno-non-template-friend -Wold-style-cast -Woverloaded-virtual -Wno-pmf-conversions -Wsign-promo -Wvirtual-inheritance
Objective-C and Objective-C++ Language Options
-fconstant-string-class=class-name -fgnu-runtime -fnext-runtime -fno-nil-receivers -fobjc-abi-version=n -fobjc-call-cxx-cdtors -fobjc-direct-dispatch -fobjc-exceptions -fobjc-gc -fobjc-nilcheck -fobjc-std=objc1 -fno-local-ivars -fivar-visibility=[public|protected|private|package] -freplace-objc-classes -fzero-link -gen-decls -Wassign-intercept -Wno-protocol -Wselector -Wstrict-selector-match -Wundeclared-selector
Diagnostic Message Formatting Options
-fmessage-length=n -fdiagnostics-show-location=[once|every-line] -fdiagnostics-color=[auto|never|always] -fno-diagnostics-show-option -fno-diagnostics-show-caret
Warning Options
-fsyntax-only -fmax-errors=n -Wpedantic -pedantic-errors -w -Wextra -Wall -Waddress -Waggregate-return -Wno-aggressive-loop-optimizations -Warray-bounds -Warray-bounds=n -Wno-attributes -Wbool-compare -Wno-builtin-macro-redefined -Wc90-c99-compat -Wc99-c11-compat -Wc++-compat -Wc++11-compat -Wc++14-compat -Wcast-align -Wcast-qual -Wchar-subscripts -Wchkp -Wclobbered -Wcomment -Wconditionally-supported -Wconversion -Wcoverage-mismatch -Wno-cpp -Wdate-time -Wdelete-incomplete -Wno-deprecated -Wno-deprecated-declarations -Wno-designated-init -Wdisabled-optimization -Wno-discarded-qualifiers -Wno-discarded-array-qualifiers -Wno-div-by-zero -Wdouble-promotion -Wduplicated-cond -Wempty-body -Wenum-compare -Wno-endif-labels -Werror -Werror=* -Wfatal-errors -Wfloat-equal -Wformat -Wformat=2 -Wno-format-contains-nul -Wno-format-extra-args -Wformat-nonliteral -Wformat-security -Wformat-signedness -Wformat-y2k -Wframe-address -Wframe-larger-than=len -Wno-free-nonheap-object -Wjump-misses-init -Wignored-qualifiers -Wignored-attributes -Wincompatible-pointer-types -Wimplicit -Wimplicit-function-declaration -Wimplicit-int -Winit-self -Winline -Wno-int-conversion -Wno-int-to-pointer-cast -Winvalid-memory-model -Wno-invalid-offsetof -Winvalid-pch -Wlarger-than=len -Wlogical-op -Wlogical-not-parentheses -Wlong-long -Wmain -Wmaybe-uninitialized -Wmemset-transposed-args -Wmisleading-indentation -Wmissing-braces -Wmissing-field-initializers -Wmissing-include-dirs -Wno-multichar -Wnonnull -Wnonnull-compare -Wnormalized=[none|id|nfc|nfkc] -Wnull-dereference -Wodr -Wno-overflow -Wopenmp-simd -Woverride-init-side-effects -Woverlength-strings -Wpacked -Wpacked-bitfield-compat -Wpadded -Wparentheses -Wno-pedantic-ms-format -Wplacement-new -Wplacement-new=n -Wpointer-arith -Wno-pointer-to-int-cast -Wno-pragmas -Wredundant-decls -Wno-return-local-addr -Wreturn-type -Wsequence-point -Wshadow -Wno-shadow-ivar -Wshift-overflow -Wshift-overflow=n -Wshift-count-negative -Wshift-count-overflow -Wshift-negative-value -Wsign-compare -Wsign-conversion -Wfloat-conversion -Wno-scalar-storage-order -Wsizeof-pointer-memaccess -Wsizeof-array-argument -Wstack-protector -Wstack-usage=len -Wstrict-aliasing -Wstrict-aliasing=n -Wstrict-overflow -Wstrict-overflow=n -Wsuggest-attribute=[pure|const|noreturn|format] -Wsuggest-final-types -Wsuggest-final-methods -Wsuggest-override -Wmissing-format-attribute -Wsubobject-linkage -Wswitch -Wswitch-default -Wswitch-enum -Wswitch-bool -Wsync-nand -Wsystem-headers -Wtautological-compare -Wtrampolines -Wtrigraphs -Wtype-limits -Wundef -Wuninitialized -Wunknown-pragmas -Wunsafe-loop-optimizations -Wunsuffixed-float-constants -Wunused -Wunused-function -Wunused-label -Wunused-local-typedefs -Wunused-parameter -Wno-unused-result -Wunused-value -Wunused-variable -Wunused-const-variable -Wunused-const-variable=n -Wunused-but-set-parameter -Wunused-but-set-variable -Wuseless-cast -Wvariadic-macros -Wvector-operation-performance -Wvla -Wvolatile-register-var -Wwrite-strings -Wzero-as-null-pointer-constant -Whsa
C and Objective-C-only Warning Options
-Wbad-function-cast -Wmissing-declarations -Wmissing-parameter-type -Wmissing-prototypes -Wnested-externs -Wold-style-declaration -Wold-style-definition -Wstrict-prototypes -Wtraditional -Wtraditional-conversion -Wdeclaration-after-statement -Wpointer-sign
Debugging Options
-g -glevel -gcoff -gdwarf -gdwarf-version -ggdb -grecord-gcc-switches -gno-record-gcc-switches -gstabs -gstabs+ -gstrict-dwarf -gno-strict-dwarf -gvms -gxcoff -gxcoff+ -gz[=type] -fdebug-prefix-map=old=new -fdebug-types-section -feliminate-dwarf2-dups -fno-eliminate-unused-debug-types -femit-struct-debug-baseonly -femit-struct-debug-reduced -femit-struct-debug-detailed[=spec-list] -feliminate-unused-debug-symbols -femit-class-debug-always -fno-merge-debug-strings -fno-dwarf2-cfi-asm -fvar-tracking -fvar-tracking-assignments
Optimization Options
-faggressive-loop-optimizations -falign-functions[=n] -falign-jumps[=n] -falign-labels[=n] -falign-loops[=n] -fassociative-math -fauto-profile -fauto-profile[=path] -fauto-inc-dec -fbranch-probabilities -fbranch-target-load-optimize -fbranch-target-load-optimize2 -fbtr-bb-exclusive -fcaller-saves -fcombine-stack-adjustments -fconserve-stack -fcompare-elim -fcprop-registers -fcrossjumping -fcse-follow-jumps -fcse-skip-blocks -fcx-fortran-rules -fcx-limited-range -fdata-sections -fdce -fdelayed-branch -fdelete-null-pointer-checks -fdevirtualize -fdevirtualize-speculatively -fdevirtualize-at-ltrans -fdse -fearly-inlining -fipa-sra -fexpensive-optimizations -ffat-lto-objects -ffast-math -ffinite-math-only -ffloat-store -fexcess-precision=style -fforward-propagate -ffp-contract=style -ffunction-sections -fgcse -fgcse-after-reload -fgcse-las -fgcse-lm -fgraphite-identity -fgcse-sm -fhoist-adjacent-loads -fif-conversion -fif-conversion2 -findirect-inlining -finline-functions -finline-functions-called-once -finline-limit=n -finline-small-functions -fipa-cp -fipa-cp-clone -fipa-cp-alignment -fipa-pta -fipa-profile -fipa-pure-const -fipa-reference -fipa-icf -fira-algorithm=algorithm -fira-region=region -fira-hoist-pressure -fira-loop-pressure -fno-ira-share-save-slots -fno-ira-share-spill-slots -fisolate-erroneous-paths-dereference -fisolate-erroneous-paths-attribute -fivopts -fkeep-inline-functions -fkeep-static-functions -fkeep-static-consts -flive-range-shrinkage -floop-block -floop-interchange -floop-strip-mine -floop-unroll-and-jam -floop-nest-optimize -floop-parallelize-all -flra-remat -flto -flto-compression-level -flto-partition=alg -fmerge-all-constants -fmerge-constants -fmodulo-sched -fmodulo-sched-allow-regmoves -fmove-loop-invariants -fno-branch-count-reg -fno-defer-pop -fno-function-cse -fno-guess-branch-probability -fno-inline -fno-math-errno -fno-peephole -fno-peephole2 -fno-sched-interblock -fno-sched-spec -fno-signed-zeros -fno-toplevel-reorder -fno-trapping-math -fno-zero-initialized-in-bss -fomit-frame-pointer -foptimize-sibling-calls -fpartial-inlining -fpeel-loops -fpredictive-commoning -fprefetch-loop-arrays -fprofile-correction -fprofile-use -fprofile-use=path -fprofile-values -fprofile-reorder-functions -freciprocal-math -free -frename-registers -freorder-blocks -freorder-blocks-algorithm=algorithm -freorder-blocks-and-partition -freorder-functions -frerun-cse-after-loop -freschedule-modulo-scheduled-loops -frounding-math -fsched2-use-superblocks -fsched-pressure -fsched-spec-load -fsched-spec-load-dangerous -fsched-stalled-insns-dep[=n] -fsched-stalled-insns[=n] -fsched-group-heuristic -fsched-critical-path-heuristic -fsched-spec-insn-heuristic -fsched-rank-heuristic -fsched-last-insn-heuristic -fsched-dep-count-heuristic -fschedule-fusion -fschedule-insns -fschedule-insns2 -fsection-anchors -fselective-scheduling -fselective-scheduling2 -fsel-sched-pipelining -fsel-sched-pipelining-outer-loops -fsemantic-interposition -fshrink-wrap -fsignaling-nans -fsingle-precision-constant -fsplit-ivs-in-unroller -fsplit-paths -fsplit-wide-types -fssa-backprop -fssa-phiopt -fstdarg-opt -fstrict-aliasing -fstrict-overflow -fthread-jumps -ftracer -ftree-bit-ccp -ftree-builtin-call-dce -ftree-ccp -ftree-ch -ftree-coalesce-vars -ftree-copy-prop -ftree-dce -ftree-dominator-opts -ftree-dse -ftree-forwprop -ftree-fre -ftree-loop-if-convert -ftree-loop-if-convert-stores -ftree-loop-im -ftree-phiprop -ftree-loop-distribution -ftree-loop-distribute-patterns -ftree-loop-ivcanon -ftree-loop-linear -ftree-loop-optimize -ftree-loop-vectorize -ftree-parallelize-loops=n -ftree-pre -ftree-partial-pre -ftree-pta -ftree-reassoc -ftree-sink -ftree-slsr -ftree-sra -ftree-switch-conversion -ftree-tail-merge -ftree-ter -ftree-vectorize -ftree-vrp -funconstrained-commons -funit-at-a-time -funroll-all-loops -funroll-loops -funsafe-loop-optimizations -funsafe-math-optimizations -funswitch-loops -fipa-ra -fvariable-expansion-in-unroller -fvect-cost-model -fvpt -fweb -fwhole-program -fwpa -fuse-linker-plugin --param name=value-O -O0 -O1 -O2 -O3 -Os -Ofast -Og
Program Instrumentation Options
-p -pg -fprofile-arcs --coverage -ftest-coverage -fprofile-dir=path -fprofile-generate -fprofile-generate=path -fsanitize=style -fsanitize-recover -fsanitize-recover=style -fasan-shadow-offset=number -fsanitize-sections=s1,s2,... -fsanitize-undefined-trap-on-error -fbounds-check -fcheck-pointer-bounds -fchkp-check-incomplete-type -fchkp-first-field-has-own-bounds -fchkp-narrow-bounds -fchkp-narrow-to-innermost-array -fchkp-optimize -fchkp-use-fast-string-functions -fchkp-use-nochk-string-functions -fchkp-use-static-bounds -fchkp-use-static-const-bounds -fchkp-treat-zero-dynamic-size-as-infinite -fchkp-check-read -fchkp-check-read -fchkp-check-write -fchkp-store-bounds -fchkp-instrument-calls -fchkp-instrument-marked-only -fchkp-use-wrappers -fstack-protector -fstack-protector-all -fstack-protector-strong -fstack-protector-explicit -fstack-check -fstack-limit-register=reg -fstack-limit-symbol=sym -fno-stack-limit -fsplit-stack -fvtable-verify=[std|preinit|none] -fvtv-counts -fvtv-debug -finstrument-functions -finstrument-functions-exclude-function-list=sym,sym,... -finstrument-functions-exclude-file-list=file,file,...
Preprocessor Options
-Aquestion=answer -A-question[=answer] -C -dD -dI -dM -dN -Dmacro[=defn] -E -H -idirafter dir -include file -imacros file -iprefix file -iwithprefix dir -iwithprefixbefore dir -isystem dir -imultilib dir -isysroot dir -M -MM -MF -MG -MP -MQ -MT -nostdinc -P -fdebug-cpp -ftrack-macro-expansion -fworking-directory -remap -trigraphs -undef -Umacro -Wp,option -Xpreprocessor option -no-integrated-cpp
Assembler Option
-Wa,option -Xassembler option
Linker Options
object-file-name -fuse-ld=linker -llibrary -nostartfiles -nodefaultlibs -nostdlib -pie -rdynamic -s -static -static-libgcc -static-libstdc++ -static-libasan -static-libtsan -static-liblsan -static-libubsan -static-libmpx -static-libmpxwrappers -shared -shared-libgcc -symbolic -T script -Wl,option -Xlinker option -u symbol -z keyword
Directory Options
-Bprefix -Idir -iplugindir=dir -iquotedir -Ldir -no-canonical-prefixes -I- --sysroot=dir --no-sysroot-suffix
Code Generation Options
-fcall-saved-reg -fcall-used-reg -ffixed-reg -fexceptions -fnon-call-exceptions -fdelete-dead-exceptions -funwind-tables -fasynchronous-unwind-tables -fno-gnu-unique -finhibit-size-directive -fno-common -fno-ident -fpcc-struct-return -fpic -fPIC -fpie -fPIE -fno-plt -fno-jump-tables -frecord-gcc-switches -freg-struct-return -fshort-enums -fshort-wchar -fverbose-asm -fpack-struct[=n] -fleading-underscore -ftls-model=model -fstack-reuse=reuse_level -ftrapv -fwrapv -fvisibility=[default|internal|hidden|protected] -fstrict-volatile-bitfields -fsync-libcalls
Developer Options
-dletters -dumpspecs -dumpmachine -dumpversion -fchecking -fdbg-cnt-list -fdbg-cnt=counter-value-list -fdisable-ipa-pass_name -fdisable-rtl-pass_name -fdisable-rtl-pass-name=range-list -fdisable-tree-pass_name -fdisable-tree-pass-name=range-list -fdump-noaddr -fdump-unnumbered -fdump-unnumbered-links -fdump-translation-unit[-n] -fdump-class-hierarchy[-n] -fdump-ipa-all -fdump-ipa-cgraph -fdump-ipa-inline -fdump-passes -fdump-rtl-pass -fdump-rtl-pass=filename -fdump-statistics -fdump-tree-all -fdump-tree-original[-n] -fdump-tree-optimized[-n] -fdump-tree-cfg -fdump-tree-alias -fdump-tree-ch -fdump-tree-ssa[-n] -fdump-tree-pre[-n] -fdump-tree-ccp[-n] -fdump-tree-dce[-n] -fdump-tree-gimple[-raw] -fdump-tree-dom[-n] -fdump-tree-dse[-n] -fdump-tree-phiprop[-n] -fdump-tree-phiopt[-n] -fdump-tree-backprop[-n] -fdump-tree-forwprop[-n] -fdump-tree-nrv -fdump-tree-vect -fdump-tree-sink -fdump-tree-sra[-n] -fdump-tree-forwprop[-n] -fdump-tree-fre[-n] -fdump-tree-vtable-verify -fdump-tree-vrp[-n] -fdump-tree-split-paths[-n] -fdump-tree-storeccp[-n] -fdump-final-insns=file -fcompare-debug[=opts] -fcompare-debug-second -fenable-kind-pass -fenable-kind-pass=range-list -fira-verbose=n -flto-report -flto-report-wpa -fmem-report-wpa -fmem-report -fpre-ipa-mem-report -fpost-ipa-mem-report -fopt-info -fopt-info-options[=file] -fprofile-report -frandom-seed=string -fsched-verbose=n -fsel-sched-verbose -fsel-sched-dump-cfg -fsel-sched-pipelining-verbose -fstats -fstack-usage -ftime-report -fvar-tracking-assignments-toggle -gtoggle -print-file-name=library -print-libgcc-file-name -print-multi-directory -print-multi-lib -print-multi-os-directory -print-prog-name=program -print-search-dirs -Q -print-sysroot -print-sysroot-headers-suffix -save-temps -save-temps=cwd -save-temps=obj -time[=file]
Machine-Dependent Options
AArch64 Options-mabi=name -mbig-endian -mlittle-endian -mgeneral-regs-only -mcmodel=tiny -mcmodel=small -mcmodel=large -mstrict-align -momit-leaf-frame-pointer -mno-omit-leaf-frame-pointer -mtls-dialect=desc -mtls-dialect=traditional -mtls-size=size -mfix-cortex-a53-835769 -mno-fix-cortex-a53-835769 -mfix-cortex-a53-843419 -mno-fix-cortex-a53-843419 -mlow-precision-recip-sqrt -mno-low-precision-recip-sqrt-march=name -mcpu=name -mtune=name

Adapteva Epiphany Options-mhalf-reg-file -mprefer-short-insn-regs -mbranch-cost=num -mcmove -mnops=num -msoft-cmpsf -msplit-lohi -mpost-inc -mpost-modify -mstack-offset=num -mround-nearest -mlong-calls -mshort-calls -msmall16 -mfp-mode=mode -mvect-double -max-vect-align=num -msplit-vecmove-early -m1reg-reg

ARC Options-mbarrel-shifter -mcpu=cpu -mA6 -mARC600 -mA7 -mARC700 -mdpfp -mdpfp-compact -mdpfp-fast -mno-dpfp-lrsr -mea -mno-mpy -mmul32x16 -mmul64 -matomic -mnorm -mspfp -mspfp-compact -mspfp-fast -msimd -msoft-float -mswap -mcrc -mdsp-packa -mdvbf -mlock -mmac-d16 -mmac-24 -mrtsc -mswape -mtelephony -mxy -misize -mannotate-align -marclinux -marclinux_prof -mlong-calls -mmedium-calls -msdata -mucb-mcount -mvolatile-cache -malign-call -mauto-modify-reg -mbbit-peephole -mno-brcc -mcase-vector-pcrel -mcompact-casesi -mno-cond-exec -mearly-cbranchsi -mexpand-adddi -mindexed-loads -mlra -mlra-priority-none -mlra-priority-compact mlra-priority-noncompact -mno-millicode -mmixed-code -mq-class -mRcq -mRcw -msize-level=level -mtune=cpu -mmultcost=num -munalign-prob-threshold=probability -mmpy-option=multo -mdiv-rem -mcode-density -mll64 -mfpu=fpu

ARM Options-mapcs-frame -mno-apcs-frame -mabi=name -mapcs-stack-check -mno-apcs-stack-check -mapcs-float -mno-apcs-float -mapcs-reentrant -mno-apcs-reentrant -msched-prolog -mno-sched-prolog -mlittle-endian -mbig-endian -mfloat-abi=name -mfp16-format=name-mthumb-interwork -mno-thumb-interwork -mcpu=name -march=name -mfpu=name -mtune=name -mprint-tune-info -mstructure-size-boundary=n -mabort-on-noreturn -mlong-calls -mno-long-calls -msingle-pic-base -mno-single-pic-base -mpic-register=reg -mnop-fun-dllimport -mpoke-function-name -mthumb -marm -mtpcs-frame -mtpcs-leaf-frame -mcaller-super-interworking -mcallee-super-interworking -mtp=name -mtls-dialect=dialect -mword-relocations -mfix-cortex-m3-ldrd -munaligned-access -mneon-for-64bits -mslow-flash-data -masm-syntax-unified -mrestrict-it

AVR Options-mmcu=mcu -maccumulate-args -mbranch-cost=cost -mcall-prologues -mint8 -mn_flash=size -mno-interrupts -mrelax -mrmw -mstrict-X -mtiny-stack -nodevicelib -Waddr-space-convert -Wmisspelled-isr

Blackfin Options-mcpu=cpu[-sirevision] -msim -momit-leaf-frame-pointer -mno-omit-leaf-frame-pointer -mspecld-anomaly -mno-specld-anomaly -mcsync-anomaly -mno-csync-anomaly -mlow-64k -mno-low64k -mstack-check-l1 -mid-shared-library -mno-id-shared-library -mshared-library-id=n -mleaf-id-shared-library -mno-leaf-id-shared-library -msep-data -mno-sep-data -mlong-calls -mno-long-calls -mfast-fp -minline-plt -mmulticore -mcorea -mcoreb -msdram -micplb

C6X Options-mbig-endian -mlittle-endian -march=cpu -msim -msdata=sdata-type

CRIS Options-mcpu=cpu -march=cpu -mtune=cpu -mmax-stack-frame=n -melinux-stacksize=n -metrax4 -metrax100 -mpdebug -mcc-init -mno-side-effects -mstack-align -mdata-align -mconst-align -m32-bit -m16-bit -m8-bit -mno-prologue-epilogue -mno-gotplt -melf -maout -melinux -mlinux -sim -sim2 -mmul-bug-workaround -mno-mul-bug-workaround

CR16 Options-mmac -mcr16cplus -mcr16c -msim -mint32 -mbit-ops-mdata-model=model

Darwin Options-all_load -allowable_client -arch -arch_errors_fatal -arch_only -bind_at_load -bundle -bundle_loader -client_name -compatibility_version -current_version -dead_strip -dependency-file -dylib_file -dylinker_install_name -dynamic -dynamiclib -exported_symbols_list -filelist -flat_namespace -force_cpusubtype_ALL -force_flat_namespace -headerpad_max_install_names -iframework -image_base -init -install_name -keep_private_externs -multi_module -multiply_defined -multiply_defined_unused -noall_load -no_dead_strip_inits_and_terms -nofixprebinding -nomultidefs -noprebind -noseglinkedit -pagezero_size -prebind -prebind_all_twolevel_modules -private_bundle -read_only_relocs -sectalign -sectobjectsymbols -whyload -seg1addr -sectcreate -sectobjectsymbols -sectorder -segaddr -segs_read_only_addr -segs_read_write_addr -seg_addr_table -seg_addr_table_filename -seglinkedit -segprot -segs_read_only_addr -segs_read_write_addr -single_module -static -sub_library -sub_umbrella -twolevel_namespace -umbrella -undefined -unexported_symbols_list -weak_reference_mismatches -whatsloaded -F -gused -gfull -mmacosx-version-min=version -mkernel -mone-byte-bool

DEC Alpha Options-mno-fp-regs -msoft-float -mieee -mieee-with-inexact -mieee-conformant -mfp-trap-mode=mode -mfp-rounding-mode=mode -mtrap-precision=mode -mbuild-constants -mcpu=cpu-type -mtune=cpu-type -mbwx -mmax -mfix -mcix -mfloat-vax -mfloat-ieee -mexplicit-relocs -msmall-data -mlarge-data -msmall-text -mlarge-text -mmemory-latency=time

FR30 Options-msmall-model -mno-lsim

FT32 Options-msim -mlra -mnodiv

FRV Options-mgpr-32 -mgpr-64 -mfpr-32 -mfpr-64 -mhard-float -msoft-float -malloc-cc -mfixed-cc -mdword -mno-dword -mdouble -mno-double -mmedia -mno-media -mmuladd -mno-muladd -mfdpic -minline-plt -mgprel-ro -multilib-library-pic -mlinked-fp -mlong-calls -malign-labels -mlibrary-pic -macc-4 -macc-8 -mpack -mno-pack -mno-eflags -mcond-move -mno-cond-move -moptimize-membar -mno-optimize-membar -mscc -mno-scc -mcond-exec -mno-cond-exec -mvliw-branch -mno-vliw-branch -mmulti-cond-exec -mno-multi-cond-exec -mnested-cond-exec -mno-nested-cond-exec -mtomcat-stats -mTLS -mtls -mcpu=cpu

GNU/Linux Options-mglibc -muclibc -mmusl -mbionic -mandroid -tno-android-cc -tno-android-ld

H8/300 Options-mrelax -mh -ms -mn -mexr -mno-exr -mint32 -malign-300

HPPA Options-march=architecture-type -mcaller-copies -mdisable-fpregs -mdisable-indexing -mfast-indirect-calls -mgas -mgnu-ld -mhp-ld -mfixed-range=register-range -mjump-in-delay -mlinker-opt -mlong-calls -mlong-load-store -mno-disable-fpregs -mno-disable-indexing -mno-fast-indirect-calls -mno-gas -mno-jump-in-delay -mno-long-load-store -mno-portable-runtime -mno-soft-float -mno-space-regs -msoft-float -mpa-risc-1-0 -mpa-risc-1-1 -mpa-risc-2-0 -mportable-runtime -mschedule=cpu-type -mspace-regs -msio -mwsio -munix=unix-std -nolibdld -static -threads

IA-64 Options-mbig-endian -mlittle-endian -mgnu-as -mgnu-ld -mno-pic -mvolatile-asm-stop -mregister-names -msdata -mno-sdata -mconstant-gp -mauto-pic -mfused-madd -minline-float-divide-min-latency -minline-float-divide-max-throughput -mno-inline-float-divide -minline-int-divide-min-latency -minline-int-divide-max-throughput -mno-inline-int-divide -minline-sqrt-min-latency -minline-sqrt-max-throughput -mno-inline-sqrt -mdwarf2-asm -mearly-stop-bits -mfixed-range=register-range -mtls-size=tls-size -mtune=cpu-type -milp32 -mlp64 -msched-br-data-spec -msched-ar-data-spec -msched-control-spec -msched-br-in-data-spec -msched-ar-in-data-spec -msched-in-control-spec -msched-spec-ldc -msched-spec-control-ldc -msched-prefer-non-data-spec-insns -msched-prefer-non-control-spec-insns -msched-stop-bits-after-every-cycle -msched-count-spec-in-critical-path -msel-sched-dont-check-control-spec -msched-fp-mem-deps-zero-cost -msched-max-memory-insns-hard-limit -msched-max-memory-insns=max-insns

LM32 Options-mbarrel-shift-enabled -mdivide-enabled -mmultiply-enabled -msign-extend-enabled -muser-enabled

M32R/D Options-m32r2 -m32rx -m32r -mdebug -malign-loops -mno-align-loops -missue-rate=number -mbranch-cost=number -mmodel=code-size-model-type -msdata=sdata-type -mno-flush-func -mflush-func=name -mno-flush-trap -mflush-trap=number -G num

M32C Options-mcpu=cpu -msim -memregs=number

M680x0 Options-march=arch -mcpu=cpu -mtune=tune -m68000 -m68020 -m68020-40 -m68020-60 -m68030 -m68040 -m68060 -mcpu32 -m5200 -m5206e -m528x -m5307 -m5407 -mcfv4e -mbitfield -mno-bitfield -mc68000 -mc68020 -mnobitfield -mrtd -mno-rtd -mdiv -mno-div -mshort -mno-short -mhard-float -m68881 -msoft-float -mpcrel -malign-int -mstrict-align -msep-data -mno-sep-data -mshared-library-id=n -mid-shared-library -mno-id-shared-library -mxgot -mno-xgot

MCore Options-mhardlit -mno-hardlit -mdiv -mno-div -mrelax-immediates -mno-relax-immediates -mwide-bitfields -mno-wide-bitfields -m4byte-functions -mno-4byte-functions -mcallgraph-data -mno-callgraph-data -mslow-bytes -mno-slow-bytes -mno-lsim -mlittle-endian -mbig-endian -m210 -m340 -mstack-increment

MeP Options-mabsdiff -mall-opts -maverage -mbased=n -mbitops -mc=n -mclip -mconfig=name -mcop -mcop32 -mcop64 -mivc2 -mdc -mdiv -meb -mel -mio-volatile -ml -mleadz -mm -mminmax -mmult -mno-opts -mrepeat -ms -msatur -msdram -msim -msimnovec -mtf -mtiny=n

MicroBlaze Options-msoft-float -mhard-float -msmall-divides -mcpu=cpu -mmemcpy -mxl-soft-mul -mxl-soft-div -mxl-barrel-shift -mxl-pattern-compare -mxl-stack-check -mxl-gp-opt -mno-clearbss -mxl-multiply-high -mxl-float-convert -mxl-float-sqrt -mbig-endian -mlittle-endian -mxl-reorder -mxl-mode-app-model

MIPS Options-EL -EB -march=arch -mtune=arch -mips1 -mips2 -mips3 -mips4 -mips32 -mips32r2 -mips32r3 -mips32r5 -mips32r6 -mips64 -mips64r2 -mips64r3 -mips64r5 -mips64r6 -mips16 -mno-mips16 -mflip-mips16 -minterlink-compressed -mno-interlink-compressed -minterlink-mips16 -mno-interlink-mips16 -mabi=abi -mabicalls -mno-abicalls -mshared -mno-shared -mplt -mno-plt -mxgot -mno-xgot -mgp32 -mgp64 -mfp32 -mfpxx -mfp64 -mhard-float -msoft-float -mno-float -msingle-float -mdouble-float -modd-spreg -mno-odd-spreg -mabs=mode -mnan=encoding -mdsp -mno-dsp -mdspr2 -mno-dspr2 -mmcu -mmno-mcu -meva -mno-eva -mvirt -mno-virt -mxpa -mno-xpa -mmicromips -mno-micromips -mfpu=fpu-type -msmartmips -mno-smartmips -mpaired-single -mno-paired-single -mdmx -mno-mdmx -mips3d -mno-mips3d -mmt -mno-mt -mllsc -mno-llsc -mlong64 -mlong32 -msym32 -mno-sym32 -Gnum -mlocal-sdata -mno-local-sdata -mextern-sdata -mno-extern-sdata -mgpopt -mno-gopt -membedded-data -mno-embedded-data -muninit-const-in-rodata -mno-uninit-const-in-rodata -mcode-readable=setting -msplit-addresses -mno-split-addresses -mexplicit-relocs -mno-explicit-relocs -mcheck-zero-division -mno-check-zero-division -mdivide-traps -mdivide-breaks -mmemcpy -mno-memcpy -mlong-calls -mno-long-calls -mmad -mno-mad -mimadd -mno-imadd -mfused-madd -mno-fused-madd -nocpp -mfix-24k -mno-fix-24k -mfix-r4000 -mno-fix-r4000 -mfix-r4400 -mno-fix-r4400 -mfix-r10000 -mno-fix-r10000 -mfix-rm7000 -mno-fix-rm7000 -mfix-vr4120 -mno-fix-vr4120 -mfix-vr4130 -mno-fix-vr4130 -mfix-sb1 -mno-fix-sb1 -mflush-func=func -mno-flush-func -mbranch-cost=num -mbranch-likely -mno-branch-likely -mcompact-branches=policy -mfp-exceptions -mno-fp-exceptions -mvr4130-align -mno-vr4130-align -msynci -mno-synci -mrelax-pic-calls -mno-relax-pic-calls -mmcount-ra-address -mframe-header-opt -mno-frame-header-opt

MMIX Options-mlibfuncs -mno-libfuncs -mepsilon -mno-epsilon -mabi=gnu -mabi=mmixware -mzero-extend -mknuthdiv -mtoplevel-symbols -melf -mbranch-predict -mno-branch-predict -mbase-addresses -mno-base-addresses -msingle-exit -mno-single-exit

MN10300 Options-mmult-bug -mno-mult-bug -mno-am33 -mam33 -mam33-2 -mam34 -mtune=cpu-type -mreturn-pointer-on-d0 -mno-crt0 -mrelax -mliw -msetlb

Moxie Options-meb -mel -mmul.x -mno-crt0

MSP430 Options-msim -masm-hex -mmcu= -mcpu= -mlarge -msmall -mrelax -mwarn-mcu -mcode-region= -mdata-region= -msilicon-errata= -msilicon-errata-warn= -mhwmult= -minrt

NDS32 Options-mbig-endian -mlittle-endian -mreduced-regs -mfull-regs -mcmov -mno-cmov -mperf-ext -mno-perf-ext -mv3push -mno-v3push -m16bit -mno-16bit -misr-vector-size=num -mcache-block-size=num -march=arch -mcmodel=code-model -mctor-dtor -mrelax

Nios II Options-G num -mgpopt=option -mgpopt -mno-gpopt -mel -meb -mno-bypass-cache -mbypass-cache -mno-cache-volatile -mcache-volatile -mno-fast-sw-div -mfast-sw-div -mhw-mul -mno-hw-mul -mhw-mulx -mno-hw-mulx -mno-hw-div -mhw-div -mcustom-insn=N -mno-custom-insn -mcustom-fpu-cfg=name -mhal -msmallc -msys-crt0=name -msys-lib=name -march=arch -mbmx -mno-bmx -mcdx -mno-cdx

Nvidia PTX Options-m32 -m64 -mmainkernel -moptimize

PDP-11 Options-mfpu -msoft-float -mac0 -mno-ac0 -m40 -m45 -m10 -mbcopy -mbcopy-builtin -mint32 -mno-int16 -mint16 -mno-int32 -mfloat32 -mno-float64 -mfloat64 -mno-float32 -mabshi -mno-abshi -mbranch-expensive -mbranch-cheap -munix-asm -mdec-asm

picoChip Options-mae=ae_type -mvliw-lookahead=N -msymbol-as-address -mno-inefficient-warnings

PowerPC OptionsSee RS/6000 and PowerPC Options.

RL78 Options-msim -mmul=none -mmul=g13 -mmul=g14 -mallregs -mcpu=g10 -mcpu=g13 -mcpu=g14 -mg10 -mg13 -mg14 -m64bit-doubles -m32bit-doubles

RS/6000 and PowerPC Options-mcpu=cpu-type -mtune=cpu-type -mcmodel=code-model -mpowerpc64 -maltivec -mno-altivec -mpowerpc-gpopt -mno-powerpc-gpopt -mpowerpc-gfxopt -mno-powerpc-gfxopt -mmfcrf -mno-mfcrf -mpopcntb -mno-popcntb -mpopcntd -mno-popcntd -mfprnd -mno-fprnd -mcmpb -mno-cmpb -mmfpgpr -mno-mfpgpr -mhard-dfp -mno-hard-dfp -mfull-toc -mminimal-toc -mno-fp-in-toc -mno-sum-in-toc -m64 -m32 -mxl-compat -mno-xl-compat -mpe -malign-power -malign-natural -msoft-float -mhard-float -mmultiple -mno-multiple -msingle-float -mdouble-float -msimple-fpu -mstring -mno-string -mupdate -mno-update -mavoid-indexed-addresses -mno-avoid-indexed-addresses -mfused-madd -mno-fused-madd -mbit-align -mno-bit-align -mstrict-align -mno-strict-align -mrelocatable -mno-relocatable -mrelocatable-lib -mno-relocatable-lib -mtoc -mno-toc -mlittle -mlittle-endian -mbig -mbig-endian -mdynamic-no-pic -maltivec -mswdiv -msingle-pic-base -mprioritize-restricted-insns=priority -msched-costly-dep=dependence_type -minsert-sched-nops=scheme -mcall-sysv -mcall-netbsd -maix-struct-return -msvr4-struct-return -mabi=abi-type -msecure-plt -mbss-plt -mblock-move-inline-limit=num -misel -mno-isel -misel=yes -misel=no -mspe -mno-spe -mspe=yes -mspe=no -mpaired -mgen-cell-microcode -mwarn-cell-microcode -mvrsave -mno-vrsave -mmulhw -mno-mulhw -mdlmzb -mno-dlmzb -mfloat-gprs=yes -mfloat-gprs=no -mfloat-gprs=single -mfloat-gprs=double -mprototype -mno-prototype -msim -mmvme -mads -myellowknife -memb -msdata -msdata=opt -mreadonly-in-sdata -mvxworks -G num -pthread -mrecip -mrecip=opt -mno-recip -mrecip-precision -mno-recip-precision -mveclibabi=type -mfriz -mno-friz -mpointers-to-nested-functions -mno-pointers-to-nested-functions -msave-toc-indirect -mno-save-toc-indirect -mpower8-fusion -mno-mpower8-fusion -mpower8-vector -mno-power8-vector -mcrypto -mno-crypto -mhtm -mno-htm -mdirect-move -mno-direct-move -mquad-memory -mno-quad-memory -mquad-memory-atomic -mno-quad-memory-atomic -mcompat-align-parm -mno-compat-align-parm -mupper-regs-df -mno-upper-regs-df -mupper-regs-sf -mno-upper-regs-sf -mupper-regs -mno-upper-regs -mfloat128 -mno-float128 -mfloat128-hardware -mno-float128-hardware -mlra -mno-lra

RX Options-m64bit-doubles -m32bit-doubles -fpu -nofpu-mcpu=-mbig-endian-data -mlittle-endian-data -msmall-data -msim -mno-sim-mas100-syntax -mno-as100-syntax-mrelax-mmax-constant-size=-mint-register=-mpid-mallow-string-insns -mno-allow-string-insns-mjsr-mno-warn-multiple-fast-interrupts-msave-acc-in-interrupts

S/390 and zSeries Options-mtune=cpu-type -march=cpu-type -mhard-float -msoft-float -mhard-dfp -mno-hard-dfp -mlong-double-64 -mlong-double-128 -mbackchain -mno-backchain -mpacked-stack -mno-packed-stack -msmall-exec -mno-small-exec -mmvcle -mno-mvcle -m64 -m31 -mdebug -mno-debug -mesa -mzarch -mhtm -mvx -mzvector -mtpf-trace -mno-tpf-trace -mfused-madd -mno-fused-madd -mwarn-framesize -mwarn-dynamicstack -mstack-size -mstack-guard -mhotpatch=halfwords,halfwords

Score Options-meb -mel -mnhwloop -muls -mmac -mscore5 -mscore5u -mscore7 -mscore7d

SH Options-m1 -m2 -m2e -m2a-nofpu -m2a-single-only -m2a-single -m2a -m3 -m3e -m4-nofpu -m4-single-only -m4-single -m4 -m4a-nofpu -m4a-single-only -m4a-single -m4a -m4al -mb -ml -mdalign -mrelax -mbigtable -mfmovd -mrenesas -mno-renesas -mnomacsave -mieee -mno-ieee -mbitops -misize -minline-ic_invalidate -mpadstruct -mspace -mprefergot -musermode -multcost=number -mdiv=strategy -mdivsi3_libfunc=name -mfixed-range=register-range -maccumulate-outgoing-args -matomic-model=atomic-model -mbranch-cost=num -mzdcbranch -mno-zdcbranch -mcbranch-force-delay-slot -mfused-madd -mno-fused-madd -mfsca -mno-fsca -mfsrra -mno-fsrra -mpretend-cmove -mtas

Solaris 2 Options-mclear-hwcap -mno-clear-hwcap -mimpure-text -mno-impure-text -pthreads -pthread

SPARC Options-mcpu=cpu-type -mtune=cpu-type -mcmodel=code-model -mmemory-model=mem-model -m32 -m64 -mapp-regs -mno-app-regs -mfaster-structs -mno-faster-structs -mflat -mno-flat -mfpu -mno-fpu -mhard-float -msoft-float -mhard-quad-float -msoft-quad-float -mstack-bias -mno-stack-bias -mstd-struct-return -mno-std-struct-return -munaligned-doubles -mno-unaligned-doubles -muser-mode -mno-user-mode -mv8plus -mno-v8plus -mvis -mno-vis -mvis2 -mno-vis2 -mvis3 -mno-vis3 -mcbcond -mno-cbcond -mfmaf -mno-fmaf -mpopc -mno-popc -mfix-at697f -mfix-ut699

SPU Options-mwarn-reloc -merror-reloc -msafe-dma -munsafe-dma -mbranch-hints -msmall-mem -mlarge-mem -mstdmain -mfixed-range=register-range -mea32 -mea64 -maddress-space-conversion -mno-address-space-conversion -mcache-size=cache-size -matomic-updates -mno-atomic-updates

System V Options-Qy -Qn -YP,paths -Ym,dir

TILE-Gx Options-mcpu=CPU -m32 -m64 -mbig-endian -mlittle-endian -mcmodel=code-model

TILEPro Options-mcpu=cpu -m32

V850 Options-mlong-calls -mno-long-calls -mep -mno-ep -mprolog-function -mno-prolog-function -mspace -mtda=n -msda=n -mzda=n -mapp-regs -mno-app-regs -mdisable-callt -mno-disable-callt -mv850e2v3 -mv850e2 -mv850e1 -mv850es -mv850e -mv850 -mv850e3v5 -mloop -mrelax -mlong-jumps -msoft-float -mhard-float -mgcc-abi -mrh850-abi -mbig-switch

VAX Options-mg -mgnu -munix

Visium Options-mdebug -msim -mfpu -mno-fpu -mhard-float -msoft-float -mcpu=cpu-type -mtune=cpu-type -msv-mode -muser-mode

VMS Options-mvms-return-codes -mdebug-main=prefix -mmalloc64 -mpointer-size=size

VxWorks Options-mrtp -non-static -Bstatic -Bdynamic -Xbind-lazy -Xbind-now

x86 Options-mtune=cpu-type -march=cpu-type -mtune-ctrl=feature-list -mdump-tune-features -mno-default -mfpmath=unit -masm=dialect -mno-fancy-math-387 -mno-fp-ret-in-387 -msoft-float -mno-wide-multiply -mrtd -malign-double -mpreferred-stack-boundary=num -mincoming-stack-boundary=num -mcld -mcx16 -msahf -mmovbe -mcrc32 -mrecip -mrecip=opt -mvzeroupper -mprefer-avx128 -mmmx -msse -msse2 -msse3 -mssse3 -msse4.1 -msse4.2 -msse4 -mavx -mavx2 -mavx512f -mavx512pf -mavx512er -mavx512cd -mavx512vl -mavx512bw -mavx512dq -mavx512ifma -mavx512vbmi -msha -maes -mpclmul -mfsgsbase -mrdrnd -mf16c -mfma -mprefetchwt1 -mclflushopt -mxsavec -mxsaves -msse4a -m3dnow -mpopcnt -mabm -mbmi -mtbm -mfma4 -mxop -mlzcnt -mbmi2 -mfxsr -mxsave -mxsaveopt -mrtm -mlwp -mmpx -mmwaitx -mclzero-mpku -mthreads -mms-bitfields -mno-align-stringops -minline-all-stringops -minline-stringops-dynamically -mstringop-strategy=alg -mmemcpy-strategy=strategy -mmemset-strategy=strategy -mpush-args -maccumulate-outgoing-args -m128bit-long-double -m96bit-long-double -mlong-double-64 -mlong-double-80 -mlong-double-128 -mregparm=num -msseregparm -mveclibabi=type -mvect8-ret-in-mem -mpc32 -mpc64 -mpc80 -mstackrealign -momit-leaf-frame-pointer -mno-red-zone -mno-tls-direct-seg-refs -mcmodel=code-model -mabi=name -maddress-mode=mode -m32 -m64 -mx32 -m16 -miamcu -mlarge-data-threshold=num -msse2avx -mfentry -mrecord-mcount -mnop-mcount -m8bit-idiv -mavx256-split-unaligned-load -mavx256-split-unaligned-store -malign-data=type -mstack-protector-guard=guard -mmitigate-rop -mindirect-branch=choice -mfunction-return=choice -mindirect-branch-register

x86 Windows Options-mconsole -mcygwin -mno-cygwin -mdll -mnop-fun-dllimport -mthread -municode -mwin32 -mwindows -fno-set-stack-executable

Xstormy16 Options-msim

Xtensa Options-mconst16 -mno-const16 -mfused-madd -mno-fused-madd -mforce-no-pic -mserialize-volatile -mno-serialize-volatile -mtext-section-literals -mno-text-section-literals -mauto-litpools -mno-auto-litpools -mtarget-align -mno-target-align -mlongcalls -mno-longcalls

zSeries OptionsSee S/390 and zSeries Options.


Options Controlling the Kind of Output

Compilation can involve up to four stages: preprocessing, compilationproper, assembly and linking, always in that order. GCC is capable ofpreprocessing and compiling several files either into severalassembler input files, or into one assembler input file; then eachassembler input file produces an object file, and linking combines allthe object files (those newly compiled, and those specified as input)into an executable file.

For any given input file, the file name suffix determines what kind ofcompilation is done:

C source code that must be preprocessed.
C source code that should not be preprocessed.
C++ source code that should not be preprocessed.
Objective-C source code. Note that you must link with the libobjclibrary to make an Objective-C program work.
Objective-C source code that should not be preprocessed.
Objective-C++ source code. Note that you must link with the libobjclibrary to make an Objective-C++ program work. Note that .M refersto a literal capital M.
Objective-C++ source code that should not be preprocessed.
C, C++, Objective-C or Objective-C++ header file to be turned into aprecompiled header (default), or C, C++ header file to be turned into anAda spec (via the -fdump-ada-spec switch).
C++ source code that must be preprocessed. Note that in .cxx,the last two letters must both be literally x. Likewise,.C refers to a literal capital C.
Objective-C++ source code that must be preprocessed.
Objective-C++ source code that should not be preprocessed.
C++ header file to be turned into a precompiled header or Ada spec.
Fixed form Fortran source code that should not be preprocessed.
Fixed form Fortran source code that must be preprocessed (with the traditionalpreprocessor).
Free form Fortran source code that should not be preprocessed.
Free form Fortran source code that must be preprocessed (with thetraditional preprocessor).
Go source code.
Ada source code file that contains a library unit declaration (adeclaration of a package, subprogram, or generic, or a genericinstantiation), or a library unit renaming declaration (a package,generic, or subprogram renaming declaration). Such files are alsocalled specs.
Ada source code file containing a library unit body (a subprogram orpackage body). Such files are also called bodies.
Assembler code.
Assembler code that must be preprocessed.
An object file to be fed straight into linking.Any file name with no recognized suffix is treated this way.

You can specify the input language explicitly with the -x option:

-x language
Specify explicitly the language for the following input files(rather than letting the compiler choose a default based on the filename suffix). This option applies to all following input files untilthe next -x option. Possible values for language are:

        c  c-header  cpp-output        c++  c++-header  c++-cpp-output        objective-c  objective-c-header  objective-c-cpp-output        objective-c++ objective-c++-header objective-c++-cpp-output        assembler  assembler-with-cpp        ada        f77  f77-cpp-input f95  f95-cpp-input        go        java
-x none
Turn off any specification of a language, so that subsequent files arehandled according to their file name suffixes (as they are if -xhas not been used at all).

If you only want some of the stages of compilation, you can use-x (or filename suffixes) to tell gcc where to start, andone of the options -c, -S, or -E to say wheregcc is to stop. Note that some combinations (for example,-x cpp-output -E) instruct gcc to do nothing at all.

Compile or assemble the source files, but do not link. The linkingstage simply is not done. The ultimate output is in the form of anobject file for each source file.

By default, the object file name for a source file is made by replacingthe suffix .c, .i, .s, etc., with .o.

Unrecognized input files, not requiring compilation or assembly, areignored.

Stop after the stage of compilation proper; do not assemble. The outputis in the form of an assembler code file for each non-assembler inputfile specified.

By default, the assembler file name for a source file is made byreplacing the suffix .c, .i, etc., with .s.

Input files that don't require compilation are ignored.

Stop after the preprocessing stage; do not run the compiler proper. Theoutput is in the form of preprocessed source code, which is sent to thestandard output.

Input files that don't require preprocessing are ignored.

-o file
Place output in file file. This applies to whateversort of output is being produced, whether it be an executable file,an object file, an assembler file or preprocessed C code.

If -o is not specified, the default is to put an executablefile in a.out, the object file forsource.suffix in source.o, itsassembler file in source.s, a precompiled header file insource.suffix.gch, and all preprocessed C source onstandard output.

Print (on standard error output) the commands executed to run the stagesof compilation. Also print the version number of the compiler driverprogram and of the preprocessor and the compiler proper.
Like -v except the commands are not executed and argumentsare quoted unless they contain only alphanumeric characters or "./-_".This is useful for shell scripts to capture the driver-generated command lines.
Print (on the standard output) a description of the command-line optionsunderstood by gcc. If the -v option is also specifiedthen --help is also passed on to the various processesinvoked by gcc, so that they can display the command-line optionsthey accept. If the -Wextra option has also been specified(prior to the --help option), then command-line options thathave no documentation associated with them are also displayed.
Print (on the standard output) a description of target-specific command-lineoptions for each tool. For some targets extra target-specificinformation may also be printed.
Print (on the standard output) a description of the command-lineoptions understood by the compiler that fit into all specified classesand qualifiers. These are the supported classes:
Display all of the optimization options supported by thecompiler.
Display all of the options controlling warning messagesproduced by the compiler.
Display target-specific options. Unlike the--target-help option however, target-specific options of thelinker and assembler are not displayed. This is because thosetools do not currently support the extended --help= syntax.
Display the values recognized by the --paramoption.
Display the options supported for language, wherelanguage is the name of one of the languages supported in thisversion of GCC.
Display the options that are common to all languages.

These are the supported qualifiers:

Display only those options that are undocumented.
Display options taking an argument that appears after an equalsign in the same continuous piece of text, such as:--help=target.
Display options taking an argument that appears as a separate wordfollowing the original option, such as: -o output-file.

Thus for example to display all the undocumented target-specificswitches supported by the compiler, use:


The sense of a qualifier can be inverted by prefixing it with the^ character, so for example to display all binary warningoptions (i.e., ones that are either on or off and that do not take anargument) that have a description, use:


The argument to --help= should not consist solely of invertedqualifiers.

Combining several classes is possible, although this usuallyrestricts the output so much that there is nothing to display. Onecase where it does work, however, is when one of the classes istarget. For example, to display all the target-specificoptimization options, use:


The --help= option can be repeated on the command line. Eachsuccessive use displays its requested class of options, skippingthose that have already been displayed.

If the -Q option appears on the command line before the--help= option, then the descriptive text displayed by--help= is changed. Instead of describing the displayedoptions, an indication is given as to whether the option is enabled,disabled or set to a specific value (assuming that the compilerknows this at the point where the --help= option is used).

Here is a truncated example from the ARM port of gcc:

          % gcc -Q -mabi=2 --help=target -c          The following options are target specific:          -mabi=                                2          -mabort-on-noreturn                   [disabled]          -mapcs                                [disabled]

The output is sensitive to the effects of previous command-lineoptions, so for example it is possible to find out which optimizationsare enabled at -O2 by using:

        -Q -O2 --help=optimizers

Alternatively you can discover which binary optimizations are enabledby -O3 by using:

        gcc -c -Q -O3 --help=optimizers > /tmp/O3-opts        gcc -c -Q -O2 --help=optimizers > /tmp/O2-opts        diff /tmp/O2-opts /tmp/O3-opts | grep enabled
Display the version number and copyrights of the invoked GCC.
Normally the gcc program exits with the code of 1 if anyphase of the compiler returns a non-success return code. If you specify-pass-exit-codes, the gcc program instead returns withthe numerically highest error produced by any phase returning an errorindication. The C, C++, and Fortran front ends return 4 if an internalcompiler error is encountered.
Use pipes rather than temporary files for communication between thevarious stages of compilation. This fails to work on some systems wherethe assembler is unable to read from a pipe; but the GNU assembler hasno trouble.
Process file after the compiler reads in the standard specsfile, in order to override the defaults which the gcc driverprogram uses when determining what switches to pass to cc1,cc1plus, as, ld, etc. More than one-specs=file can be specified on the command line, and theyare processed in order, from left to right.
Invoke all subcommands under a wrapper program. The name of thewrapper program and its parameters are passed as a comma separatedlist.

        gcc -c t.c -wrapper gdb,--args

This invokes all subprograms of gcc undergdb --args, thus the invocation of cc1 isgdb --args cc1 ....
Load the plugin code in file, assumed to be ashared object to be dlopen'd by the compiler. The base name ofthe shared object file is used to identify the plugin for thepurposes of argument parsing (See-fplugin-arg-name-key=value below).Each plugin should define the callback functions specified in thePlugins API.
Define an argument called key with a value of valuefor the plugin called name.
For C and C++ source and include files, generate corresponding Ada specs.
In conjunction with -fdump-ada-spec[-slim] above, generateAda specs as child units of parent unit.
For input files in any language, generate corresponding Godeclarations in file. This generates Go "const","type", "var", and "func" declarations which may be auseful way to start writing a Go interface to code written in someother language.
Read command-line options from file. The options read areinserted in place of the original @file option. If filedoes not exist, or cannot be read, then the option will be treatedliterally, and not removed.

Options in file are separated by whitespace.