Reading specs from /usr/lib/gcc/x86_64-redhat-linux/3.4.6/specs
Usage: gcc [options] file...
Options:
-pass-exit-codes Exit with highest error code from a phase
--help Display this information
--target-help Display target specific command line options
-dumpspecs Display all of the built in spec strings
-dumpversion Display the version of the compiler
-dumpmachine Display the compiler's target processor
-print-search-dirs Display the directories in the compiler's search path
-print-libgcc-file-name Display the name of the compiler's companion library
-print-file-name=<lib> Display the full path to library <lib>
-print-prog-name=<prog> Display the full path to compiler component <prog>
-print-multi-directory Display the root directory for versions of libgcc
-print-multi-lib Display the mapping between command line options and
multiple library search directories
-print-multi-os-directory Display the relative path to OS libraries
-Wa,<options> Pass comma-separated <options> on to the assembler
-Wp,<options> Pass comma-separated <options> on to the preprocessor
-Wl,<options> Pass comma-separated <options> on to the linker
-Xassembler <arg> Pass <arg> on to the assembler
-Xpreprocessor <arg> Pass <arg> on to the preprocessor
-Xlinker <arg> Pass <arg> on to the linker
-save-temps Do not delete intermediate files
-pipe Use pipes rather than intermediate files
-time Time the execution of each subprocess
-specs=<file> Override built-in specs with the contents of <file>
-std=<standard> Assume that the input sources are for <standard>
-B <directory> Add <directory> to the compiler's search paths
-b <machine> Run gcc for target <machine>, if installed
-V <version> Run gcc version number <version>, if installed
-v Display the programs invoked by the compiler
-### Like -v but options quoted and commands not executed
-E Preprocess only; do not compile, assemble or link
-S Compile only; do not assemble or link
-c Compile and assemble, but do not link
-o <file> Place the output into <file>
-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.
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --disable-checking --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-java-awt=gtk --host=x86_64-redhat-linux
Thread model: posix
gcc version 3.4.6 20060404 (Red Hat 3.4.6-3)
/usr/libexec/gcc/x86_64-redhat-linux/3.4.6/cc1 -quiet -v help-dummy -quiet -dumpbase help-dummy -mtune=k8 -auxbase help-dummy -version --help -o /tmp/cc0yUXP4.s
The following options are language-independent:
--help Display this information
--param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
--target-help This switch lacks documentation
--version This switch lacks documentation
-G<number> Put global and static data smaller than <number> bytes into a special section (on some targets)
-O<number> Set optimization level to <number>
-Os Optimize for space rather than speed
-W This switch is deprecated; use -Wextra instead
-Waggregate-return Warn about returning structures, unions or arrays
-Wcast-align Warn about pointer casts which increase alignment
-Wdeprecated-declarations Warn about uses of __attribute__((deprecated)) declarations
-Wdisabled-optimization Warn when an optimization pass is disabled
-Werror Treat all warnings as errors
-Wextra Print extra (possibly unwanted) warnings
-Winline Warn when an inlined function cannot be inlined
-Wlarger-than-<number> Warn if an object is larger than <number> bytes
-Wmissing-noreturn Warn about functions which might be candidates for __attribute__((noreturn))
-Wpacked Warn when the packed attribute has no effect on struct layout
-Wpadded Warn when padding is required to align structure members
-Wshadow Warn when one local variable shadows another
-Wstrict-aliasing Warn about code which might break strict aliasing rules
-Wswitch Warn about enumerated switches, with no default, missing a case
-Wswitch-default Warn about enumerated switches missing a "default:" statement
-Wswitch-enum Warn about all enumerated switches missing a specific case
-Wsystem-headers Do not suppress warnings from system headers
-Wuninitialized Warn about uninitialized automatic variables
-Wunreachable-code Warn about code that will never be executed
-Wunused Enable all -Wunused- warnings
-Wunused-function Warn when a function is unused
-Wunused-label Warn when a label is unused
-Wunused-parameter Warn when a function parameter is unused
-Wunused-value Warn when an expression value is unused
-Wunused-variable Warn when a variable is unused
-aux-info <file> Emit declaration information into <file>
-aux-info= This switch lacks documentation
-auxbase This switch lacks documentation
-auxbase-strip This switch lacks documentation
-d<letters> Enable dumps from specific passes of the compiler
-dumpbase <file> Set the file basename to be used for dumps
-fPIC This switch lacks documentation
-fPIE This switch lacks documentation
-fabi-version= This switch lacks documentation
-falign-functions Align the start of functions
-falign-functions= This switch lacks documentation
-falign-jumps Align labels which are only reached by jumping
-falign-jumps= This switch lacks documentation
-falign-labels Align all labels
-falign-labels= This switch lacks documentation
-falign-loops Align the start of loops
-falign-loops= This switch lacks documentation
-fargument-alias Specify that arguments may alias each other and globals
-fargument-noalias Assume arguments may alias globals but not each other
-fargument-noalias-global Assume arguments alias neither each other nor globals
-fasynchronous-unwind-tables Generate unwind tables that are exact at each instruction boundary
-fbounds-check Generate code to check bounds before indexing arrays
-fbranch-count-reg Replace add, compare, branch with branch on count register
-fbranch-probabilities Use profiling information for branch probabilities
-fbranch-target-load-optimize Perform branch target load optimization before prologue / epilogue threading
-fbranch-target-load-optimize2 Perform branch target load optimization after prologue / epilogue threading
-fcall-saved-<register> Mark <register> as being preserved across functions
-fcall-used-<register> Mark <register> as being corrupted by function calls
-fcaller-saves Save registers around function calls
-fcommon Do not put uninitialized globals in the common section
-fcprop-registers Perform a register copy-propagation optimization pass
-fcrossjumping Perform cross-jumping optimization
-fcse-follow-jumps When running CSE, follow jumps to their targets
-fcse-skip-blocks When running CSE, follow conditional jumps
-fdata-sections Place data items into their own section
-fdefer-pop Defer popping functions args from stack until later
-fdelayed-branch Attempt to fill delay slots of branch instructions
-fdelete-null-pointer-checks Delete useless null pointer checks
-fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped
diagnostics
-fdump-unnumbered Suppress output of instruction numbers and line number notes in debugging dumps
-feliminate-dwarf2-dups Perform DWARF2 duplicate elimination
-feliminate-unused-debug-symbols Perform unused type elimination in debug info
-feliminate-unused-debug-types Perform unused type elimination in debug info
-fexceptions Enable exception handling
-fexpensive-optimizations Perform a number of minor, expensive optimizations
-ffast-math This switch lacks documentation
-ffinite-math-only Assume no NaNs or infinities are generated
-ffixed-<register> Mark <register> as being unavailable to the compiler
-ffloat-store Do not store floats in registers
-fforce-addr Copy memory address constants into registers before use
-fforce-mem Copy memory operands into registers before use
-fframe-base-loclist Allow use of DWARF2 location lists for frame base
-ffunction-cse Allow function addresses to be held in registers
-ffunction-sections Place each function into its own section
-fgcse Perform global common subexpression elimination
-fgcse-las Perform redundant load after store elimination in global common subexpression elimination
-fgcse-lm Perform enhanced load motion during global common subexpression elimination
-fgcse-sm Perform store motion after global common subexpression elimination
-fguess-branch-probability Enable guessing of branch probabilities
-fident Process #ident directives
-fif-conversion Perform conversion of conditional jumps to branchless equivalents
-fif-conversion2 Perform conversion of conditional jumps to conditional execution
-finhibit-size-directive Do not generate .size directives
-finline Pay attention to the "inline" keyword
-finline-functions This switch lacks documentation
-finline-limit- This switch lacks documentation
-finline-limit=<number> Limit the size of inlined functions to <number>
-finstrument-functions Instrument function entry and exit with profiling calls
-fkeep-inline-functions Generate code for functions even if they are fully inlined
-fkeep-static-consts Emit static const variables even if they are not used
-fleading-underscore Give external symbols a leading underscore
-floop-optimize Perform loop optimizations
-fmath-errno Set errno after built-in math functions
-fmem-report Report on permanent memory allocation
-fmerge-all-constants Attempt to merge identical constants and constant variables
-fmerge-constants Attempt to merge identical constants across compilation units
-fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
-fmove-all-movables Force all loop invariant computations out of loops
-fnew-ra Use graph-coloring register allocation
-fnon-call-exceptions Support synchronous non-call exceptions
-fold-unroll-all-loops Perform loop unrolling for all loops
-fold-unroll-loops Perform loop unrolling when iteration count is known
-fomit-frame-pointer When possible do not generate stack frames
-foptimize-register-move Do the full register move optimization pass
-foptimize-sibling-calls Optimize sibling and tail recursive calls
-fpack-struct Pack structure members together without holes
-fpcc-struct-return Return small aggregates in memory, not registers
-fpeel-loops Perform loop peeling
-fpeephole Enable machine specific peephole optimizations
-fpeephole2 Enable an RTL peephole pass before sched2
-fpic Generate position-independent code if possible
-fpie Generate position-independent code for executables if possible
-fprefetch-loop-arrays Generate prefetch instructions, if available, for arrays in loops
-fprofile Enable basic program profiling code
-fprofile-arcs Insert arc-based program profiling code
-fprofile-generate Enable common options for generating profile info for profile feedback directed optimizations
-fprofile-use Enable common options for performing profile feedback directed optimizations
-fprofile-values Insert code to profile values of expressions
-frandom-seed This switch lacks documentation
-frandom-seed=<string> Make compile reproducible using <string>
-freduce-all-givs Strength reduce all loop general induction variables
-freg-struct-return Return small aggregates in registers
-fregmove Enables a register move optimization
-frename-registers Perform a register renaming optimization pass
-freorder-blocks Reorder basic blocks to improve code placement
-freorder-functions Reorder functions to improve code placement
-frerun-cse-after-loop Add a common subexpression elimination pass after loop optimizations
-frerun-loop-opt Run the loop optimizer twice
-frounding-math Disable optimizations that assume default FP rounding behavior
-fsched-interblock Enable scheduling across basic blocks
-fsched-spec Allow speculative motion of non-loads
-fsched-spec-load Allow speculative motion of some loads
-fsched-spec-load-dangerous Allow speculative motion of more loads
-fsched-stalled-insns Allow premature scheduling of queued insns
-fsched-stalled-insns-dep Set dependence distance checking in premature scheduling of queued insns
-fsched-stalled-insns-dep= -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling
of queued insns
-fsched-stalled-insns= -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely
scheduled
-fsched-verbose=<number> Set the verbosity level of the scheduler
-fsched2-use-superblocks If scheduling post reload, do superblock scheduling
-fsched2-use-traces If scheduling post reload, do trace scheduling
-fschedule-insns Reschedule instructions before register allocation
-fschedule-insns2 Reschedule instructions after register allocation
-fshared-data Mark data as shared rather than private
-fsignaling-nans Disable optimizations observable by IEEE signaling NaNs
-fsingle-precision-constant Convert floating point constants to single precision constants
-fstack-check Insert stack checking code into the program
-fstack-limit This switch lacks documentation
-fstack-limit-register=<register> Trap if the stack goes past <register>
-fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
-fstrength-reduce Perform strength reduction optimizations
-fstrict-aliasing Assume strict aliasing rules apply
-fsyntax-only Check for syntax errors, then stop
-ftest-coverage Create data files needed by "gcov"
-fthread-jumps Perform jump threading optimizations
-ftime-report Report the time taken by each compiler pass
-ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation
model
-ftracer Perform superblock formation via tail duplication
-ftrapping-math Assume floating-point operations can trap
-ftrapv Trap for signed overflow in addition, subtraction and multiplication
-funit-at-a-time Compile whole compilation unit at a time
-funroll-all-loops Perform loop unrolling for all loops
-funroll-loops Perform loop unrolling when iteration count is known
-funsafe-math-optimizations Allow math optimizations that may violate IEEE or ISO standards
-funswitch-loops Perform loop unswitching
-funwind-tables Just generate unwind tables for exception handling
-fvar-tracking Perform variable tracking
-fverbose-asm Add extra commentary to assembler output
-fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
-fvpt Use expression value profiles in optimizations
-fweb Construct webs and split unrelated uses of single variable
-fwrapv Assume signed arithmetic overflow wraps around
-fwritable-strings Store strings in writable data section
-fzero-initialized-in-bss Put zero initialized data in the bss section
-g Generate debug information in default format
-gcoff Generate debug information in COFF format
-gdwarf-2 Generate debug information in DWARF v2 format
-ggdb Generate debug information in default extended format
-gstabs Generate debug information in STABS format
-gstabs+ Generate debug information in extended STABS format
-gvms Generate debug information in VMS format
-gxcoff Generate debug information in XCOFF format
-gxcoff+ Generate debug information in extended XCOFF format
-m This switch lacks documentation
-o <file> Place output into <file>
-p Enable function profiling
-pedantic Issue warnings needed for strict compliance to the standard
-pedantic-errors Like -pedantic but issue them as errors
-quiet Do not display functions compiled or elapsed time
-version This switch lacks documentation
-w Suppress warnings
The --param option recognizes the following as parameters:
max-inline-insns-single The maximum number of instructions in a single function eligible for inlining
max-inline-insns-auto The maximum number of instructions when automatically inlining
max-inline-insns-rtl The maximum number of instructions for the RTL inliner
max-delay-slot-insn-search The maximum number of instructions to consider to fill a delay slot
max-delay-slot-live-search The maximum number of instructions to consider to find accurate live register information
max-pending-list-length The maximum length of scheduling's pending operations list
large-function-insns The size of function body to be considered large
large-function-growth Maximal growth due to inlining of large function (in percent)
inline-unit-growth how much can given compilation unit grow because of the inlining (in percent)
max-gcse-memory The maximum amount of memory to be allocated by GCSE
max-gcse-passes The maximum number of passes to make when doing GCSE
max-unrolled-insns The maximum number of instructions to consider to unroll in a loop
max-average-unrolled-insns The maximum number of instructions to consider to unroll in a loop on average
max-unroll-times The maximum number of unrollings of a single loop
max-peeled-insns The maximum number of insns of a peeled loop
max-peel-times The maximum number of peelings of a single loop
max-completely-peeled-insns The maximum number of insns of a completely peeled loop
max-completely-peel-times The maximum number of peelings of a single loop that is peeled completely
max-once-peeled-insns The maximum number of insns of a peeled loop that rolls only once
max-unswitch-insns The maximum number of insns of an unswitched loop
max-unswitch-level The maximum number of unswitchings in a single loop
hot-bb-count-fraction Select fraction of the maximal count of repetitions of basic block in program given basic
block needs to have to be considered hot
hot-bb-frequency-fraction Select fraction of the maximal frequency of executions of basic block in function given basic
block needs to have to be considered hot
tracer-dynamic-coverage-feedback The percentage of function, weighted by execution frequency, that must be covered by
trace formation. Used when profile feedback is available
tracer-dynamic-coverage The percentage of function, weighted by execution frequency, that must be covered by trace
formation. Used when profile feedback is not available
tracer-max-code-growth Maximal code growth caused by tail duplication (in percent)
tracer-min-branch-ratio Stop reverse growth if the reverse probability of best edge is less than this threshold (in
percent)
tracer-min-branch-probability-feedback Stop forward growth if the probability of best edge is less than this threshold (in
percent). Used when profile feedback is available
tracer-min-branch-probability Stop forward growth if the probability of best edge is less than this threshold (in
percent). Used when profile feedback is not available
max-crossjump-edges The maximum number of incoming edges to consider for crossjumping
max-cse-path-length The maximum length of path considered in cse
max-cselib-memory-locations The maximum memory locations recorded by cselib
max-last-value-rtl The maximum number of RTL nodes that can be recorded as combiner's last value
ggc-min-expand Minimum heap expansion to trigger garbage collection, as a percentage of the total size of the
heap
ggc-min-heapsize Minimum heap size before we start collecting garbage, in kilobytes
max-reload-search-insns The maximum number of instructions to search backward when looking for equivalent reload
min-pretend-dynamic-size The minimum size for an auto object to allocate it in the stack as if its size was dynamic
The Ada front end recognizes the following options:
-I This switch lacks documentation
-Wall This switch lacks documentation
-Wlong-long Do not warn about using "long long" when -pedantic
-Wmissing-prototypes Warn about global functions without prototypes
-Wstrict-prototypes Warn about unprototyped function declarations
-Wwrite-strings Give strings the type "array of char"
-fRTS This switch lacks documentation
-gnat<options> Specify options to GNAT
-nostdinc Do not search standard system include directories (those specified with -isystem will still be
used)
-nostdlib This switch lacks documentation
The C front end recognizes the following options:
-I, -Wall, -Wlong-long, -Wmissing-prototypes, -Wstrict-prototypes, -Wwrite-strings, -nostdinc
--output-pch= This switch lacks documentation
-A<question>=<answer> Assert the <answer> to <question>. Putting '-' before <question> disables the <answer> to
<question>
-C Do not discard comments
-CC Do not discard comments in macro expansions
-D<macro>[=<val>] Define a <macro> with <val> as its value. If just <macro> is given, <val> is taken to be 1
-H Print the name of header files as they are used
-M This switch lacks documentation
-MD Generate make dependencies and compile
-MF This switch lacks documentation
-MG Treat missing header files as generated files
-MM This switch lacks documentation
-MMD Like -MD but ignore system header files
-MP This switch lacks documentation
-MQ <target> Add a MAKE-quoted target
-MT This switch lacks documentation
-P Do not generate #line directives
-U<macro> Undefine <macro>
-Wbad-function-cast Warn about casting functions to incompatible types
-Wcast-qual Warn about casts which discard qualifiers
-Wchar-subscripts Warn about subscripts whose type is "char"
-Wcomment This switch lacks documentation
-Wcomments This switch lacks documentation
-Wconversion Warn about possibly confusing type conversions
-Wdeclaration-after-statement Warn when a declaration is found after a statement
-Wdiv-by-zero Warn about compile-time integer division by zero
-Wendif-labels Warn about stray tokens after #elif and #endif
-Werror-implicit-function-declaration Make implicit function declarations an error
-Wfloat-equal Warn if testing floating point numbers for equality
-Wformat Warn about printf/scanf/strftime/strfmon format string anomalies
-Wformat-extra-args Warn if passing too many arguments to a function for its format string
-Wformat-nonliteral Warn about format strings that are not literals
-Wformat-security Warn about possible security problems with format functions
-Wformat-y2k Warn about strftime formats yielding 2-digit years
-Wformat-zero-length This switch lacks documentation
-Wformat= This switch lacks documentation
-Wimplicit This switch lacks documentation
-Wimplicit-function-declaration Warn about implicit function declarations
-Wimplicit-int Warn when a declaration does not specify a type
-Wimport This switch lacks documentation
-Winit-self Warn about variables which are initialized to themselves.
-Winvalid-pch Warn about PCH files that are found but not used
-Wmain Warn about suspicious declarations of "main"
-Wmissing-braces Warn about possibly missing braces around initializers
-Wmissing-declarations Warn about global functions without previous declarations
-Wmissing-format-attribute Warn about functions which might be candidates for format attributes
-Wmultichar Warn about use of multi-character character constants
-Wnested-externs Warn about "extern" declarations not at file scope
-Wnonnull This switch lacks documentation
-Wold-style-definition Warn if an old-style parameter definition is used
-Wparentheses Warn about possibly missing parentheses
-Wpointer-arith Warn about function pointer arithmetic
-Wredundant-decls Warn about multiple declarations of the same object
-Wreturn-type Warn whenever a function's return type defaults to "int" (C), or about inconsistent return
types (C++)
-Wsequence-point Warn about possible violations of sequence point rules
-Wsign-compare Warn about signed-unsigned comparisons
-Wtraditional Warn about features not present in traditional C
-Wtrigraphs This switch lacks documentation
-Wundef Warn if an undefined macro is used in an #if directive
-Wunknown-pragmas Warn about unrecognized pragmas
-Wunused-macros Warn about macros defined in the main file that are not used
-ansi A synonym for -std=c89 (for C) or -std=c++98 (for C++).
-fasm Recognize the "asm" keyword
-fbuiltin Recognize built-in functions
-fbuiltin- This switch lacks documentation
-fcond-mismatch Allow the arguments of the '?' operator to have different types
-fdollars-in-identifiers Permit '$' as an identifier character
-fdump- This switch lacks documentation
-fexec-charset=<cset> Convert all strings and character constants to character set <cset>
-ffixed-form This switch lacks documentation
ffixed-line-length-<number> Set the maximum line length to <number>
-ffreestanding Do not assume that standard C libraries and "main" exist
-fhosted Assume normal C execution environment
-finput-charset= -finput-charset=<cset> Specify the default character set for source files.
-fms-extensions Don't warn about uses of Microsoft extensions
-fpch-deps This switch lacks documentation
-fpreprocessed This switch lacks documentation
-fshort-double Use the same size for double as for float
-fshort-enums Use the narrowest integer type possible for enumeration types
-fshort-wchar Force the underlying type for "wchar_t" to be "unsigned short"
-fshow-column This switch lacks documentation
-fsigned-bitfields When "signed" or "unsigned" is not given make the bitfield signed
-fsigned-char Make "char" signed by default
-ftabstop=<number> Distance between tab stops for column reporting
-funsigned-bitfields When "signed" or "unsigned" is not given make the bitfield unsigned
-funsigned-char Make "char" unsigned by default
-fwide-exec-charset=<cset> Convert all wide strings and character constants to character set <cset>
-fworking-directory Generate a #line directive pointing at the current working directory
-idirafter <dir> Add <dir> to the end of the system include path
-imacros <file> Accept definition of macros in <file>
-include <file> Include the contents of <file> before other files
-iprefix <path> Specify <path> as a prefix for next two options
-isysroot <dir> Set <dir> to be the system root directory
-isystem <dir> Add <dir> to the start of the system include path
-iwithprefix <dir> Add <dir> to the end of the system include path
-iwithprefixbefore <dir> Add <dir> to the end of the main include path
-remap Remap file names when including files
-std=c89 Conform to the ISO 1990 C standard
-std=c99 Conform to the ISO 1999 C standard
-std=c9x Deprecated in favor of -std=c99
-std=gnu89 Conform to the ISO 1990 C standard with GNU extensions
-std=gnu99 Conform to the ISO 1999 C standard with GNU extensions
-std=gnu9x Deprecated in favor of -std=gnu99
-std=iso9899:1990 Conform to the ISO 1990 C standard
-std=iso9899:199409 Conform to the ISO 1990 C standard as amended in 1994
-std=iso9899:1999 Conform to the ISO 1999 C standard
-std=iso9899:199x Deprecated in favor of -std=iso9899:1999
-traditional-cpp Enable traditional preprocessing
-trigraphs Support ISO C trigraphs
-undef Do not predefine system-specific and GCC-specific macros
-v Enable verbose output
The C++ front end recognizes the following options:
--output-pch=, -A, -C, -CC, -D, -H, -I, -M, -MD, -MF, -MG, -MM, -MMD, -MP, -MQ, -MT, -P, -U, -Wall, -Wcast-qual,
-Wchar-subscripts, -Wcomment, -Wcomments, -Wconversion, -Wendif-labels, -Wfloat-equal, -Wformat, -Wformat-extra-args,
-Wformat-nonliteral, -Wformat-security, -Wformat-y2k, -Wformat=, -Wimplicit, -Wimport, -Winit-self, -Winvalid-pch,
-Wlong-long, -Wmissing-braces, -Wmissing-format-attribute, -Wmultichar, -Wparentheses, -Wpointer-arith, -Wredundant-decls,
-Wreturn-type, -Wsign-compare, -Wtrigraphs, -Wundef, -Wunknown-pragmas, -Wunused-macros, -Wwrite-strings, -ansi, -fasm,
-fbuiltin, -fbuiltin-, -fcond-mismatch, -fdollars-in-identifiers, -fdump-, -fexec-charset=, -finput-charset=,
-fms-extensions, -fpch-deps, -fpreprocessed, -fshort-double, -fshort-enums, -fshort-wchar, -fshow-column,
-fsigned-bitfields, -fsigned-char, -ftabstop=, -funsigned-bitfields, -funsigned-char, -fwide-exec-charset=,
-fworking-directory, -idirafter, -imacros, -include, -iprefix, -isysroot, -isystem, -iwithprefix, -iwithprefixbefore,
-nostdinc, -remap, -traditional-cpp, -trigraphs, -undef, -v
-Wabi This switch lacks documentation
-Wctor-dtor-privacy Warn when all constructors and destructors are private
-Wdeprecated Warn if deprecated class, method, or field is used
-Weffc++ Warn about violations of Effective C++ style rules
-Winvalid-offsetof Warn about invalid uses of the "offsetof" macro
-Wnon-template-friend Warn when non-templatized friend functions are declared within a template
-Wnon-virtual-dtor Warn about non-virtual destructors
-Wold-style-cast Warn if a C-style cast is used in a program
-Woverloaded-virtual Warn about overloaded virtual function names
-Wpmf-conversions Warn when converting the type of pointers to member functions
-Wreorder Warn when the compiler reorders code
-Wsign-promo Warn when overload promotes from unsigned to signed
-Wsynth Warn when synthesis behavior differs from Cfront
-faccess-control Enforce class member access control semantics
-fall-virtual This switch lacks documentation
-falt-external-templates Change when template instances are emitted
-fcheck-new Check the return value of new
-fconserve-space Reduce the size of object files
-fconst-strings Make string literals "const char[]" not "char[]"
-fdefault-inline Inline member functions by default
-felide-constructors This switch lacks documentation
-fenforce-eh-specs Generate code to check exception specifications
-fenum-int-equiv This switch lacks documentation
-fexternal-templates This switch lacks documentation
-ffor-scope Scope of for-init-statement variables is local to the loop
-fgnu-keywords Recognize GNU-defined keywords
-fguiding-decls This switch lacks documentation
-fhandle-exceptions This switch lacks documentation
-fhonor-std This switch lacks documentation
-fhuge-objects Enable support for huge objects
-fimplement-inlines Export functions even if they can be inlined
-fimplicit-inline-templates Emit implicit instantiations of inline templates
-fimplicit-templates Emit implicit instantiations of templates
-flabels-ok This switch lacks documentation
-fname-mangling-version- This switch lacks documentation
-fnew-abi This switch lacks documentation
-fnonansi-builtins This switch lacks documentation
-fnonnull-objects This switch lacks documentation
-foperator-names Recognize C++ kewords like "compl" and "xor"
-foptional-diags Enable optional diagnostics
-fpermissive Downgrade conformance errors to warnings
-frepo Enable automatic template instantiation
-frtti Generate run time type descriptor information
-fsquangle This switch lacks documentation
-fstats Display statistics accumulated during compilation
-fstrict-prototype This switch lacks documentation
-ftemplate-depth-<number> Specify maximum template instantiation depth
-fthis-is-variable This switch lacks documentation
-fno-threadsafe-statics Do not generate thread-safe code for initializing local statics.
-fuse-cxa-atexit Use __cxa_atexit to register destructors
-fvisibility-inlines-hidden Marks all inlined methods as having hidden visibility
-fvtable-gc Discard unused virtual functions
-fvtable-thunks Implement vtables using thunks
-fweak Emit common-like symbols as weak symbols
-fxref Emit cross referencing information
-nostdinc++ Do not search standard system include directories for C++
-std=c++98 Conform to the ISO 1998 C++ standard
-std=gnu++98 Conform to the ISO 1998 C++ standard with GNU extensions
Target specific options:
-mno-tls-direct-seg-refs Do not use direct references against %gs when accessing tls data
-mtls-direct-seg-refs Use direct references against %gs when accessing tls data
-mno-red-zone Do not use red-zone in the x86-64 code
-mred-zone Use red-zone in the x86-64 code
-mno-ms-bitfields Use gcc default bitfield layout
-mms-bitfields Use native (MS) bitfield layout
-m32 Generate 32bit i386 code
-m64 Generate 64bit x86-64 code
-m96bit-long-double sizeof(long double) is 12
-m128bit-long-double sizeof(long double) is 16
-mno-sse3 Do not support MMX, SSE, SSE2 and SSE3 built-in functions and code generation
-msse3 Support MMX, SSE, SSE2 and SSE3 built-in functions and code generation
-mno-sse2 Do not support MMX, SSE and SSE2 built-in functions and code generation
-msse2 Support MMX, SSE and SSE2 built-in functions and code generation
-mno-sse Do not support MMX and SSE built-in functions and code generation
-msse Support MMX and SSE built-in functions and code generation
-mno-3dnow Do not support 3DNow! built-in functions
-m3dnow Support 3DNow! built-in functions
-mno-mmx Do not support MMX built-in functions
-mmmx Support MMX built-in functions
-mno-accumulate-outgoing-args Do not use push instructions to save outgoing arguments
-maccumulate-outgoing-args Use push instructions to save outgoing arguments
-mno-push-args Do not use push instructions to save outgoing arguments
-mpush-args Use push instructions to save outgoing arguments
-mno-inline-all-stringops Do not inline all known string operations
-minline-all-stringops Inline all known string operations
-mno-align-stringops Do not align destination of the string operations
-malign-stringops Align destination of the string operations
-mstack-arg-probe Enable stack probing
-momit-leaf-frame-pointer Omit the frame pointer in leaf functions
-mfancy-math-387 Generate sin, cos, sqrt for FPU
-mno-fancy-math-387 Do not generate sin, cos, sqrt for FPU
-mno-fp-ret-in-387 Do not return values of functions in FPU registers
-mfp-ret-in-387 Return values of functions in FPU registers
-mno-ieee-fp Do not use IEEE math for fp comparisons
-mieee-fp Use IEEE math for fp comparisons
-mno-svr3-shlib Uninitialized locals in .data
-msvr3-shlib Uninitialized locals in .bss
-mno-align-double Align doubles on word boundary
-malign-double Align some doubles on dword boundary
-mno-rtd Use normal calling convention
-mrtd Alternate calling convention
-mno-soft-float Use hardware fp
-msoft-float Do not use hardware fp
-mhard-float Use hardware fp
-mno-80387 Do not use hardware fp
-m80387 Use hardware fp
-mtls-dialect= Use given thread-local storage dialect
-masm= Use given assembler dialect
-mcmodel= Use given x86-64 code model
-mbranch-cost= Branches are this expensive (1-5, arbitrary units)
-mpreferred-stack-boundary= Attempt to keep stack aligned to this power of 2
-malign-functions= Function starts are aligned to this power of 2
-malign-jumps= Jump targets are aligned to this power of 2
-malign-loops= Loop code aligned to this power of 2
-mregparm= Number of registers used to pass integer arguments
-march= Generate code for given CPU
-mfpmath= Generate floating point mathematics using given instruction set
-mtune= Schedule code for given CPU
GCC
Section: GNU Tools (1)
Updated: 2003/12/05
Index Return to Main Contents
NAME
gcc,g++-GNU工程的C和C++编译器(egcs-1.1.2)
总览(SYNOPSIS)
gcc[option|filename ]...
g++[option|filename ]...
警告(WARNING)
本手册页内容摘自GNU C编译器的完整文档,仅限于解释选项的含义.
除非有人自愿维护,否则本手册页不再更新.如果发现手册页和软件之间有所矛盾,请查对Info文件, Info文件是权威文档.
如果我们发觉本手册页的内容由于过时而导致明显的混乱和抱怨时,我们就停止发布它.不可能有其他选择,象更新Info文件同时更新man手册,因为其他维护GNU CC的工作没有留给我们时间做这个. GNU工程认为man手册是过时产物,应该把时间用到别的地方.
如果需要完整和最新的文档,请查阅Info文件`gcc'或Using and Porting GNU CC (for version 2.0) (使用和移植GNU CC 2.0) 手册.二者均来自Texinfo原文件 gcc.texinfo.
描述(DESCRIPTION)
C和C++编译器是集成的.他们都要用四个步骤中的一个或多个处理输入文件: 预处理(preprocessing),编译(compilation),汇编(assembly)和连接(linking).源文件后缀名标识源文件的 语言,但是对编译器来说,后缀名控制着缺省设定:
- gcc
- 认为预处理后的文件(.i)是C文件,并且设定C形式的连接.
- g++
- 认为预处理后的文件(.i)是C++文件,并且设定C++形式的连接.
源文件后缀名指出语言种类以及后期的操作:
.c C源程序;预处理,编译,汇编.C C++源程序;预处理,编译,汇编.cc C++源程序;预处理,编译,汇编.cxx C++源程序;预处理,编译,汇编.m Objective-C源程序;预处理,编译,汇编.i 预处理后的C文件;编译,汇编.ii 预处理后的C++文件;编译,汇编.s 汇编语言源程序;汇编.S 汇编语言源程序;预处理,汇编.h 预处理器文件;通常不出现在命令行上
其他后缀名的文件被传递给连接器(linker).通常包括:
.o 目标文件(Object file).a 归档库文件(Archive file)
除非使用了-c, -S,或-E选项(或者编译错误阻止了完整的过程),否则连接总是 最后的步骤.在连接阶段中,所有对应于源程序的.o文件, -l库文件,无法识别的文件名(包括指定的 .o目标文件和.a库文件)按命令行中的顺序传递给连接器.
选项(OPTIONS)
选项必须分立给出: `-dr'完全不同于`-d -r '.
大多数`-f'和`-W'选项有两个相反的格式: -fname和 -fno-name (或-Wname和-Wno-name).这里 只列举不是默认选项的格式.
下面是所有选项的摘要,按类型分组,解释放在后面的章节中.
- 总体选项(Overall Option)
-c -S -E -o file -pipe -v -x language- 语言选项(Language Option)
- -ansi -fall-virtual -fcond-mismatch -fdollars-in-identifiers -fenum-int-equiv -fexternal-templates -fno-asm -fno-builtin -fhosted -fno-hosted -ffreestanding -fno-freestanding -fno-strict-prototype -fsigned-bitfields -fsigned-char -fthis-is-variable -funsigned-bitfields -funsigned-char -fwritable-strings -traditional -traditional-cpp -trigraphs
- 警告选项(Warning Option)
- -fsyntax-only -pedantic -pedantic-errors -w -W -Wall -Waggregate-return -Wcast-