Public domain POSIX make

This is an implementation of POSIX make.

It comes with its own makefile, naturally, and should build on most modernish Unix-style systems. (Command line options may not work properly due to differences in how getopt(3) is reset. Adjust GETOPT_RESET() in make.h for your platform, if necessary.)

The default configuration enables extensions: some from a future POSIX standard and some that are non-POSIX. Generally these extensions are compatible with GNU make:

• double-colon rules
• -include to ignore missing include files
• include files can be created if required
• ifdef/ifndef/else/endif conditionals
• lib.a(mem1.o mem2.o...) syntax for archive members
• :=/::=/:::=/+=/?=/!= macro assignments
• macro expansions can be nested
• chained inference rules
• */?/[] wildcards for filenames in target rules
• $(SRC:%.c=%.o) pattern macro expansions
• special handling of MAKE macro
• $^ internal macro
• skip duplicate entries in $^ and $?
• .PHONY special target
• -C directory and -j maxjobs command line options

When extensions are enabled adding the .POSIX target to your makefile will disable them. Other versions of make tend to allow extensions even in POSIX mode.

Setting the environment variable PDPMAKE_POSIXLY_CORRECT (its value doesn't matter) or giving the --posix option as the first on the command line also turn off extensions.