GNU 編譯器家族 GCC 內部探密(轉)

GNU 編譯器家族 GCC 內部探密(轉)[@more@]GCC使用指南

使用語法：
gcc [ option | 20041012141356.htm ]...
g++ [ option | 20041012141356.htm ]...

其中 option 為 gcc 使用時的選項(後面會再詳述)，
而 20041012141356.htm 為欲以 gcc 處理的檔案
說明：
這 C 與 C++ 的 compiler 已將產生新程式的相關程式整合起來。產
生一個新的程式需要經過四個階段：預處理、編譯、彙編,連結，
而這兩個編譯器都能將輸入的檔案做不同階段的處理。雖然原始程式
的副檔名可用來分辨編寫原始程式碼所用的語言，但不同的 compiler
，其預設的處理程式卻各不相同：

gcc 預設經由預處理過(副檔名為.i)的檔案為 C 語言，並於程
式連結階段以 C 的連結方式處理。

g++ 預設經由預處理過(副檔名為.i)的檔案為 C++ 語言，並於程

序連結階段以 C++ 的連結方式處理。


原始程式碼的副檔名指出所用編寫程式所用的語言，以及相對應的處
理方法：

.c C 原始程式 ； 預處理、編譯、彙編
.C C++ 原始程式 ； 預處理、編譯、彙編
.cc C++ 原始程式 ； 預處理、編譯、彙編
.cxx C++ 原始程式 ； 預處理、編譯、彙編
.m Objective-C 原始程式 ； 預處理、編譯、彙編
.i 已經過預處理之 C 原始程式 ； 編譯、彙編
.ii 已經過預處理之 C++ 原始程式 ； 編譯、彙編
.s 組合語言原始程式 ； 彙編
.S 組合語言原始程式 ； 預處理、彙編
.h 預處理檔案(標標頭檔案) ； (不常出現在指令行)


其他副檔名的檔案是由連結程式來處理，通常有：

.o Object file
.a Archive file


除非編譯過程出現錯誤，否則 "連結" 一定是產生一個新程式的最
後階段。然而你也可以以 -c、-s 或 -E 等選項，將整個過程自四
個階段中的其中一個停止。在連結階段，所有與原始碼相對應的
.o 檔案、程式庫、和其他無法自檔名辨明屬性的檔案(包括不以 .o
為副檔名的 object file 以及副檔名為 .a 的 archive file)都會
交由連結程式來處理(在指令行將那些檔案當作連結程式的引數傳給
連結程式)。


選項：
不同的選項必須分開來下：例如 `-dr' 這個選項就與 `-d -r' 大
不相同。

絕大部份的 `-f' 及 `-W' 選項都有正反兩種形式：-fname 及
-fno-name (或 -Wname 及 -Wno-name)。以下只列出非預設的那個
形式。

以下是所有選項的摘要。以形式來分類。選項的意義將另闢小節說
明。

一般性(概略、常用的)選項
-c -S -E -o file -pipe -v -x language

程式語言選項
-ansi -fall-virtual -fcond-mismatch
-fdollars-in-identifiers -fenum-int-equiv
-fexternal-templates -fno-asm -fno-builtin
-fno-strict-prototype -fsigned-bitfields
-fsigned-char -fthis-is-variable
-funsigned-bitfields -funsigned-char
-fwritable-strings -traditional -traditional-cpp
-trigraphs

編譯時的警告選項
-fsyntax-only -pedantic -pedantic-errors -w -W
-Wall -Waggregate-return -Wcast-align -Wcast-qual
-Wchar-subscript -Wcomment -Wconversion
-Wenum-clash -Werror -Wformat -Wid-clash-len
-Wimplicit -Winline -Wmissing-prototypes
-Wmissing-declarations -Wnested-externs -Wno-import
-Wparentheses -Wpointer-arith -Wredundant-decls
-Wreturn-type -Wshadow -Wstrict-prototypes -Wswitch
-Wtemplate-debugging -Wtraditional -Wtrigraphs
-Wuninitialized -Wunused -Wwrite-strings

除錯選項
-a -dletters -fpretend-float -g -glevel -gcoff
-gxcoff -gxcoff+ -gdwarf -gdwarf+ -gstabs -gstabs+
-ggdb -p -pg -save-temps -print-file-name=library
-print-libgcc-file-name -print-prog-name=program

最佳化選項
-fcaller-saves -fcse-follow-jumps -fcse-skip-blocks
-fdelayed-branch -felide-constructors
-fexpensive-optimizations -ffast-math -ffloat-store
-fforce-addr -fforce-mem -finline-functions
-fkeep-inline-functions -fmemoize-lookups
-fno-default-inline -fno-defer-pop
-fno-function-cse -fno-inline -fno-peephole
-fomit-frame-pointer -frerun-cse-after-loop
-fschedule-insns -fschedule-insns2
-fstrength-reduce -fthread-jumps -funroll-all-loops
-funroll-loops -O -O2

預處理選項
-Aassertion -C -dD -dM -dN -Dmacro[=defn] -E -H
-idirafter dir -include file -imacros file -iprefix
file -iwithprefix dir -M -MD -MM -MMD -nostdinc -P
-Umacro -undef

彙編程式選項
-Wa,option

連結程式選項
-llibrary -nostartfiles -nostdlib -static -shared
-symbolic -Xlinker option -Wl,option -u symbol

目錄選項
-Bprefix -Idir -I- -Ldir

Target Options
-b machine -V version

與機器(平臺)相關的選項
M680x0 Options
-m68000 -m68020 -m68020-40 -m68030 -m68040 -m68881
-mbitfield -mc68000 -mc68020 -mfpa -mnobitfield
-mrtd -mshort -msoft-float

VAX Options
-mg -mgnu -munix

SPARC Options
-mepilogue -mfpu -mhard-float -mno-fpu
-mno-epilogue -msoft-float -msparclite -mv8
-msupersparc -mcypress

Convex Options
-margcount -mc1 -mc2 -mnoargcount

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

M88K Options
-m88000 -m88100 -m88110 -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-serialize-volatile
-mno-underscores -mocs-debug-info
-mocs-frame-position -moptimize-arg-area
-mserialize-volatile -mshort-data-num -msvr3 -msvr4
-mtrap-large-shift -muse-div-instruction
-mversion-03.00 -mwarn-passed-structs

RS6000 Options
-mfp-in-toc -mno-fop-in-toc

RT Options
-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

MIPS Options
-mcpu=cpu type -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 num -nocpp

i386 Options
-m486 -mno-486 -msoft-float -mno-fp-ret-in-387

HPPA Options
-mpa-risc-1-0 -mpa-risc-1-1 -mkernel -mshared-libs
-mno-shared-libs -mlong-calls -mdisable-fpregs
-mdisable-indexing -mtrailing-colon

i960 Options
-mcpu-type -mnumerics -msoft-float
-mleaf-procedures -mno-leaf-procedures -mtail-call
-mno-tail-call -mcomplex-addr -mno-complex-addr
-mcode-align -mno-code-align -mic-compat
-mic2.0-compat -mic3.0-compat -masm-compat
-mintel-asm -mstrict-align -mno-strict-align
-mold-align -mno-old-align

DEC Alpha Options
-mfp-regs -mno-fp-regs -mno-soft-float -msoft-float

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

Code Generation Options
-fcall-saved-reg -fcall-used-reg -ffixed-reg
-finhibit-size-directive -fnonnull-objects
-fno-common -fno-ident -fno-gnu-linker
-fpcc-struct-return -fpic -fPIC
-freg-struct-returno -fshared-data -fshort-enums
-fshort-double -fvolatile -fvolatile-global
-fverbose-asm

PRAGMAS
Two `#pragma' directives are supported for GNU C++, to
permit using the same header file for two purposes: as a
definition of interfaces to a given object class, and as
the full definition of the contents of that object class.

#pragma interface
(C++ only.) Use this directive in header files
that define object classes, to save space in most
of the object files that use those classes. Nor-
mally, local copies of certain information (backup
copies of inline member functions, debugging infor-
mation, and the internal tables that implement vir-
tual functions) must be kept in each object file
that includes class definitions. You can use this
pragma to avoid such duplication. When a header
file containing `#pragma interface' is included in
a compilation, this auxiliary information will not
be generated (unless the main input source file it-
self uses `#pragma implementation'). Instead, the
object files will contain references to be resolved
at link time.

#pragma implementation

#pragma implementation "objects.h"
(C++ only.) Use this pragma in a main input file,
when you want full output from included header
files to be generated (and made globally visible).
The included header file, in turn, should use
`#pragma interface'. Backup copies of inline mem-
ber functions, debugging information, and the in-
ternal tables used to implement virtual functions
are all generated in implementation files.

If you use `#pragma implementation' with no argu-
ment, it applies to an include file with the same
basename as your source file; for example, in
`allclass.cc', `#pragma implementation' by itself
is equivalent to `#pragma implementation
"allclass.h"'. Use the string argument if you want
a single implementation file to include code from
multiple header files.

There is no way to split up the contents of a sin-
gle header file into multiple implementation files.

檔案說明
file.c C source file
file.h C header (preprocessor) file
file.i 經預處理過的 C source file
file.C C++ source file
file.cc C++ source file
file.cxx C++ source file
file.m Objective-C source file
file.s assembly language file
file.o object file
a.out link edited output
TMPDIR/cc* temporary files
LIBDIR/cpp preprocessor
LIBDIR/cc1 compiler for C
LIBDIR/cc1plus compiler for C++
LIBDIR/collect linker front end needed on some machines
LIBDIR/libgcc.a GCC subroutine library
/lib/crt[01n].o start-up routine
LIBDIR/ccrt0 additional start-up routine for C++
/lib/libc.a standard C library, 參閱 man page intro(3)
/usr/include standard directory for #include files
LIBDIR/include standard gcc directory for #include files
LIBDIR/g++-include additional g++ directory for #include

LIBDIR is usually /usr/local/lib/machine/version.
TMPDIR comes from the environment variable TMPDIR (default
/usr/tmp if available, else /tmp).