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make: Utilities in Makefiles

 
 16.2 Utilities in Makefiles
 ===========================
 
 Write the Makefile commands (and any shell scripts, such as 'configure')
 to run under 'sh' (both the traditional Bourne shell and the POSIX
 shell), not 'csh'.  Don't use any special features of 'ksh' or 'bash',
 or POSIX features not widely supported in traditional Bourne 'sh'.
 
    The 'configure' script and the Makefile rules for building and
 installation should not use any utilities directly except these:
 
      awk cat cmp cp diff echo egrep expr false grep install-info ln ls
      mkdir mv printf pwd rm rmdir sed sleep sort tar test touch tr true
 
    Compression programs such as 'gzip' can be used in the 'dist' rule.
 
    Generally, stick to the widely-supported (usually POSIX-specified)
 options and features of these programs.  For example, don't use 'mkdir
 -p', convenient as it may be, because a few systems don't support it at
 all and with others, it is not safe for parallel execution.  For a list
 of known incompatibilities, see Portable Shell Programming
 (autoconf)Portable Shell.
 
    It is a good idea to avoid creating symbolic links in makefiles,
 since a few file systems don't support them.
 
    The Makefile rules for building and installation can also use
 compilers and related programs, but should do so via 'make' variables so
 that the user can substitute alternatives.  Here are some of the
 programs we mean:
 
      ar bison cc flex install ld ldconfig lex
      make makeinfo ranlib texi2dvi yacc
 
    Use the following 'make' variables to run those programs:
 
      $(AR) $(BISON) $(CC) $(FLEX) $(INSTALL) $(LD) $(LDCONFIG) $(LEX)
      $(MAKE) $(MAKEINFO) $(RANLIB) $(TEXI2DVI) $(YACC)
 
    When you use 'ranlib' or 'ldconfig', you should make sure nothing bad
 happens if the system does not have the program in question.  Arrange to
 ignore an error from that command, and print a message before the
 command to tell the user that failure of this command does not mean a
 problem.  (The Autoconf 'AC_PROG_RANLIB' macro can help with this.)
 
    If you use symbolic links, you should implement a fallback for
 systems that don't have symbolic links.
 
    Additional utilities that can be used via Make variables are:
 
      chgrp chmod chown mknod
 
    It is ok to use other utilities in Makefile portions (or scripts)
 intended only for particular systems where you know those utilities
 exist.
 

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