BBS水木清华站∶精华区

OVERALL OPTIONS
       -x language
              Specify explicitly the language 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 `-x' op-
              tion.   Possible  values  of  language   are   `c',
              `objective-c',   `c-header',  `c++',  `cpp-output',
              `assembler', and `assembler-with-cpp'.

       -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  `-x'  has  not
              been used at all).

       If you want only some of the four stages (preprocess, com-
       pile, assemble, link), you can use `-x' (or filename  suf-
       fixes)  to tell gcc where to start, and one of the options
       `-c', `-S', or `-E' to say where gcc  is  to  stop.   Note
       that  some  combinations (for example, `-x cpp-output -E')
       instruct gcc to do nothing at all.

       -c     Compile or assemble the source files,  but  do  not
              link.  The compiler output is an object file corre-
              sponding to each source file.

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

              GCC  ignores  any  unrecognized  input files (those
              that do not require compilation or  assembly)  with
              the -c option.

       -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',  `.i',
              etc., with `.s'.  Use -o to select another name.

              GCC ignores any input files that don't require com-
              pilation.

       -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 prepro-
              cessing.

       -o file
              Place output in file file.  This applies regardless
              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 `-o' when compiling more
              than one input file, unless you  are  producing  an
              executable file as output.

              If  you  do not specify `-o', the default is to put
              an executable file in `a.out', the object file  for
              `source.suffix'  in  `source.o', its assembler file
              in `source.s', and all  preprocessed  C  source  on
              standard output.

       -v     Print  (on standard error output) the commands exe-
              cuted to run the stages of compilation.  Also print
              the  version  number of the compiler driver program
              and of the preprocessor and the compiler proper.

       -pipe  Use pipes rather than temporary files for  communi-
              cation  between  the various stages of compilation.
              This fails to work on some systems where the assem-
              bler cannot read from a pipe; but the GNU assembler
              has no trouble.