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).