NAME

       gccmakedep - create dependencies in makefiles using 'gcc -M'

SYNOPSIS

       gccmakedep [ -sseparator ] [ -fmakefile ] [ -a ] [ -- options -- ] sourcefile ...

DESCRIPTION

       The gccmakedep program calls 'gcc -M' to output makefile rules describing the dependencies
       of each sourcefile, so that make(1) knows which object files must  be  recompiled  when  a
       dependency has changed.

       By  default,  gccmakedep  places  its  output  in  the  file  named makefile if it exists,
       otherwise Makefile.  An alternate makefile may be specified with the -f option.  It  first
       searches the makefile for a line beginning with

           # DO NOT DELETE

       or one provided with the -s option, as a delimiter for the dependency output.  If it finds
       it, it will delete everything following this up to the end of the  makefile  and  put  the
       output  after this line.  If it doesn't find it, the program will append the string to the
       makefile and place the output after that.

EXAMPLE

       Normally, gccmakedep will be used in a makefile target so that typing 'make  depend'  will
       bring the dependencies up to date for the makefile.  For example,
           SRCS = file1.c file2.c ...
           CFLAGS = -O -DHACK -I../foobar -xyz
           depend:
                   gccmakedep -- $(CFLAGS) -- $(SRCS)

OPTIONS

       The  program  will  ignore any option that it does not understand, so you may use the same
       arguments that you would for gcc(1), including -D and -U options to  define  and  undefine
       symbols and -I to set the include path.

       -a     Append the dependencies to the file instead of replacing existing dependencies.

       -fmakefile
              Filename.  This allows you to specify an alternate makefile in which gccmakedep can
              place its output.  Specifying “-” as the file name (that is, -f-) sends the  output
              to standard output instead of modifying an existing file.

       -sstring
              Starting  string  delimiter.  This option permits you to specify a different string
              for gccmakedep to look for in the makefile.  The default is “# DO NOT DELETE”.

       -- options --
              If gccmakedep encounters a double hyphen  (--)  in  the  argument  list,  then  any
              unrecognized  arguments  following  it  will  be silently ignored.  A second double
              hyphen terminates this special treatment.  In this way, gccmakedep can be  made  to
              safely  ignore esoteric compiler arguments that might normally be found in a CFLAGS
              make macro (see the EXAMPLE section above).   -D,  -I,  and  -U  options  appearing
              between the pair of double hyphens are still processed normally.

SEE ALSO

       gcc(1), make(1), makedepend(1).

AUTHOR

       The  version  of  the  gccmakedep included in this X.Org Foundation release was originally
       written by the XFree86 Project based on code supplied by Hongjiu Lu.

       Colin Watson wrote this manual page, originally for the Debian Project,  based  partly  on
       the manual page for makedepend(1).