gcc.1

早期freebsd实现

.\" Copyright (c) 1991 Free Software Foundation              -*-Text-*-
.\" See section COPYING for conditions for redistribution
.\" FIXME: no info here on predefines.  Should there be?  extra for C++...
.TH CC 1 "28may1992" "GNU Tools" "GNU Tools"
.de BP
.sp
.ti \-.2i
\(**
..
.SH NAME
cc, g++ \- GNU project C and C++ Compiler (v2 preliminary)
.SH SYNOPSIS
.RB cc " [" \c
.IR option " | " filename " ].\|.\|.
.br
.RB g++ " [" \c
.IR option " | " filename " ].\|.\|.
.SH WARNING
The information in this man page is an extract from the full
documentation of the GNU C compiler, and is limited to the meaning of
the options.  This man page is not kept up to date except when
volunteers want to maintain it.

For complete and current documentation, refer to the Info file `\|\c
.B gcc\c
\&\|' or the manual
.I 
Using and Porting GNU CC (for version 2.0)\c
\&.  Both are made from the Texinfo source file
.BR gcc.texinfo .
.SH DESCRIPTION
The C and C++ compilers are integrated.  Both process input files
through one or more of four stages: preprocessing, compilation,
assembly, and linking.  Source filename suffixes identify the source
language, but which name you use for the compiler governs default
assumptions:
.TP
.B gcc
assumes preprocessed (\c
.B .i\c
\&) files are C and assumes C style linking.
.TP
.B g++
assumes preprocessed (\c
.B .i\c
\&) files are C++ and assumes C++ style linking.
.PP 
Suffixes of source file names indicate the language and kind of
processing to be done:

.ta \w'.cxx 'u
.B .c\c
\&	C source; preprocess, compile, assemble 
.br
.B .C\c
\&	C++ source; preprocess, compile, assemble
.br
.B .cc\c
\&	C++ source; preprocess, compile, assemble
.br
.B .cxx\c
\&	C++ source; preprocess, compile, assemble
.br
.B .m\c
\&	Objective-C source; preprocess, compile, assemble
.br
.B .i\c
\&	preprocessed C; compile, assemble
.br
.B .ii\c
\&	preprocessed C++; compile, assemble
.br
.B .s\c
\&	Assembler source; assemble 
.br
.B .S\c
\&	Assembler source; preprocess, assemble 
.br
.B .h\c
\&	Preprocessor file; not usually named on command line

.I ??\c
\&	Other (unrecognized) files passed to linker. 
.br
\&	Common cases:
.br
.B .o\c
\&	Object file
.br
.B .a\c
\&	Archive file

Linking is always the last stage unless you use one of the 
.BR \-c ,
.BR \-S ,
or 
.B \-E 
options to avoid it (or unless compilation errors stop the whole
process).  For the link stage, all 
.B .o
files corresponding to source files,
.B \-l 
libraries, unrecognized filenames (including named 
.B .o
object files and 
.B .a 
archives)
are passed to the linker in command-line order.

.SH OPTIONS
Options must be separate: `\|\c
.B \-dr\c
\&\|' is quite different from `\|\c
.B \-d \-r
\&\|'. 

Most `\|\c
.B \-f\c
\&\|' and `\|\c
.B \-W\c
\&\|' options have two contrary forms: 
.BI \-f name
and
.BI \-fno\- name\c
\& (or 
.BI \-W name
and
.BI \-Wno\- name\c
\&). Only the non-default forms are shown here.

Here is a summary of all the options, grouped by type.  Explanations are
in the following sections.

.hy 0
.na
.TP
.B Overall Options
.br
\-c
\-S
\-E
.RI "\-o " file
\-pipe
\-v
.RI "\-x " language

.TP
.B Language Options
\-ansi
\-fall\-virtual
\-fcond\-mismatch
\-fdollars\-in\-identifiers
\-fenum\-int\-equiv
\-fno\-asm
\-fno\-builtin
\-fno\-strict\-prototype
\-fsigned\-bitfields
\-fsigned\-char
\-fthis\-is\-variable
\-funsigned\-bitfields
\-funsigned\-char
\-fwritable\-strings
\-traditional
\-traditional\-cpp
\-trigraphs

.TP
.B Warning Options
\-fsyntax\-only
\-pedantic
\-pedantic\-errors
\-w
\-W
\-Wall
\-Waggregate\-return
\-Wcast\-align
\-Wcast\-qual
\-Wcomment
\-Wconversion
\-Wenum\-clash
\-Werror
\-Wformat
.RI \-Wid\-clash\- len
\-Wimplicit
\-Winline
\-Wmissing\-prototypes
\-Wparentheses
\-Wpointer\-arith
\-Wreturn\-type
\-Wshadow
\-Wstrict\-prototypes
\-Wswitch
\-Wtraditional
\-Wtrigraphs
\-Wuninitialized
\-Wunused
\-Wwrite\-strings

.TP
.B Debugging Options
\-a
.RI \-d letters
\-fpretend\-float
\-g
\-gstabs
\-gdwarf
\-ggdb
\-gsdb
\-p
\-pg
\-save\-temps

.TP
.B Optimization Options
\-fcaller\-saves
\-fcse\-follow\-jumps
\-fdelayed\-branch
\-felide\-constructors
\-fexpensive\-optimizations
\-ffloat\-store
\-fforce\-addr
\-fforce\-mem
\-finline
\-finline\-functions
\-fkeep\-inline\-functions
\-fmemoize\-lookups
\-fno\-default\-inline
\-fno\-defer\-pop
\-fno\-function\-cse
\-fomit\-frame\-pointer
\-frerun\-cse\-after\-loop
\-fschedule\-insns
\-fschedule\-insns2
\-fstrength\-reduce
\-fthread\-jumps
\-funroll\-all\-loops
\-funroll\-loops
\-O
\-O2

.TP
.B Preprocessor Options
\-C
\-dD
\-dM
\-dN
.RI \-D macro [\|= defn \|]
\-E
\-H
.RI "\-i " file
\-M
\-MD
\-MM
\-MMD
\-nostdinc
\-P
.RI \-U macro
\-undef

.TP
.B Linker Options
.RI \-l library
\-nostdlib
\-static

.TP
.B Directory Options
.RI \-B prefix
.RI \-I dir
\-I\-
.RI \-L dir

.TP
.B Target Options
.RI "\-b  " machine
.RI "\-V " version

.TP
.B Machine Dependent Options
.I M680x0\ Options
.br
\-m68000
\-m68020
\-m68881
\-mbitfield
\-mc68000
\-mc68020
\-mfpa
\-mnobitfield
\-mrtd
\-mshort
\-msoft\-float

.I VAX Options
.br
\-mg
\-mgnu
\-munix

.I SPARC Options
.br
\-mfpu
\-mno\-epilogue

.I Convex Options
.br
\-margcount
\-mc1
\-mc2
\-mnoargcount

.I AMD29K Options
.br
\-m29000
\-m29050
\-mbw
\-mdw
\-mkernel\-registers
\-mlarge
\-mnbw
\-mnodw
\-msmall
\-mstack\-check
\-muser\-registers

.I M88K Options
.br
\-mbig\-pic
\-mcheck\-zero\-division
\-mhandle\-large\-shift
\-midentify\-revision
\-mno\-check\-zero\-division
\-mno\-ocs\-debug\-info
\-mno\-ocs\-frame\-position
\-mno\-optimize\-arg\-area
\-mno\-underscores
\-mocs\-debug\-info
\-mocs\-frame\-position
\-moptimize\-arg\-area
.RI \-mshort\-data\- num
\-msvr3
\-msvr4
\-mtrap\-large\-shift
\-muse\-div\-instruction
\-mversion\-03.00
\-mwarn\-passed\-structs

.I RS6000 Options
.br
\-mfp\-in\-toc
\-mno\-fop\-in\-toc

.I RT Options
.br
\-mcall\-lib\-mul
\-mfp\-arg\-in\-fpregs
\-mfp\-arg\-in\-gregs
\-mfull\-fp\-blocks
\-mhc\-struct\-return
\-min\-line\-mul
\-mminimum\-fp\-blocks
\-mnohc\-struct\-return

.I MIPS Options
.br
\-mcpu=\fIcpu type\fP
\-mips2
\-mips3
\-mint64
\-mlong64
\-mlonglong128
\-mmips\-as
\-mgas
\-mrnames
\-mno\-rnames
\-mgpopt
\-mno\-gpopt
\-mstats
\-mno\-stats
\-mmemcpy
\-mno\-memcpy
\-mno\-mips\-tfile
\-mmips\-tfile
\-msoft\-float
\-mhard\-float
\-mabicalls
\-mno\-abicalls
\-mhalf\-pic
\-mno\-half\-pic
\-G \fInum\fP

.I i386 Options
.br
\-m486
\-mno486
\-msoft\-float

.TP
.B Code Generation Options
.RI +e N
.RI \-fcall\-saved\- reg
.RI \-fcall\-used\- reg
.RI \-ffixed\- reg
\-fno\-common
\-fno\-gnu\-binutils
\-fnonnull\-objects
\-fpcc\-struct\-return
\-fpic
\-fPIC
\-fshared\-data
\-fshort\-enums
\-fshort\-double
\-fvolatile
.ad b
.hy 1

.SH OVERALL OPTIONS
.TP
.BI "\-x " "language"
Specify explicitly the 
.I language\c
\& for the following input files (rather than choosing a default based
on the file name suffix) .  This option applies to all following input
files until the next `\|\c
.B \-x\c
\&\|' option.  Possible values of \c
.I language\c
\& are
`\|\c
.B c\c
\&\|', `\|\c
.B objective\-c\c
\&\|', `\|\c
.B c\-header\c
\&\|', `\|\c
.B c++\c
\&\|',
`\|\c
.B cpp\-output\c
\&\|', `\|\c
.B assembler\c
\&\|', and `\|\c
.B assembler\-with\-cpp\c
\&\|'.
.TP
.B \-x none
Turn off any specification of a language, so that subsequent files are
handled according to their file name suffixes (as they are if `\|\c
.B \-x\c
\&\|'
has not been used at all).
.PP

If you want only some of the four stages (preprocess, compile,
assemble, link), you can use
`\|\c
.B \-x\c
\&\|' (or filename suffixes) to tell \c
.B gcc\c
\& where to start, and
one of the options `\|\c
.B \-c\c
\&\|', `\|\c
.B \-S\c
\&\|', or `\|\c
.B \-E\c
\&\|' to say where
\c
.B gcc\c
\& is to stop.  Note that some combinations (for example,
`\|\c
.B \-x cpp\-output \-E\c
\&\|') instruct \c
.B gcc\c
\& to do nothing at all.
.TP
.B \-c
Compile or assemble the source files, but do not link.  The compiler
output is an object file corresponding to each source file.

By default, GCC makes the object file name for a source file by replacing
the suffix `\|\c
.B .c\c
\&\|', `\|\c
.B .i\c
\&\|', `\|\c
.B .s\c
\&\|', etc., with `\|\c
.B .o\c
\&\|'.  Use
.B \-o\c
\& to select another name.

GCC ignores any unrecognized input files (those that do not require
compilation or assembly) with the
.B \-c
option.
.TP
.B \-S
Stop after the stage of compilation proper; do not assemble.  The output
is an assembler code file for each non-assembler input
file specified.

By default, GCC makes the assembler file name for a source file by
replacing the suffix `\|\c
.B .c\c
\&\|', `\|\c
.B .i\c
\&\|', etc., with `\|\c
.B .s\c
\&\|'.  Use
.B \-o\c
\& to select another name.


GCC ignores any input files that don't require compilation.
.TP
.B \-E
Stop after the preprocessing stage; do not run the compiler proper.  The
output is preprocessed source code, which is sent to the
standard output.

GCC ignores input files which don't require preprocessing.
.TP
.BI "\-o " file\c
\&
Place output in file \c
.I file\c
\&.  This applies to whatever
sort of output GCC is producing, whether it be an executable file,
an object file, an assembler file or preprocessed C code.

Since only one output file can be specified, it does not make sense to
use `\|\c
.B \-o\c
\&\|' when compiling more than one input file, unless you are
producing an executable file as output.

If you do not specify `\|\c
.B \-o\c
\&\|', the default is to put an executable file
in `\|\c
.B a.out\c
\&\|', an object file for `\|\c
.B \c
.I source\c
\&.\c
.I suffix\c
\&\c
\&\|' in
`\|\c
.B \c
.I source\c