ioccc/2014/morgan

To build:

    make

To use:

    ./prog [arg ..]

Try:

    ./try.sh

Judges' remarks:

Think of this as a Maker Faire's make. :-)

It works reasonably well. While not super ultra-featured, it does fair well with the Makefile we supplied. Not only that, it helped uncover a bug we had in our special Makefile rules.

Author's remarks:

Remarks

This program is a tiny make(1) clone.

It is able to parse a subset of the make(1) syntax and will execute rules for goals given in arguments if they need to (based on timestamp of dependencies of rule targets).

Supported features

• Variable assignments (only recursive ones). Variable references with recursion.
• Environment variables are available.
• It is possible to specify variables in command line: name=value.
• Variables given in command line will have precedence over variables defined in Makefile, which will have precedence over environment variables.
• If no target given in command line, the first target defined will be used.
• Comments, escaped comments, escaped new lines.

It should be able to build programs of previous years with the provided Makefile found in previous contest archives. Simply use this program instead of make. It will recursively use itself for sub-make.

Limitations / Known issues

• There are a lot of memory leaks (not a single free).
• The opened file is not closed.
• The input file shall be named Makefile.
• No diagnostic message, but the exit status is non zero to indicates failure (failed command in a rule or missing target).
• Only $< and $@ are supported for automatic variables in commands.
• No parallel execution (-j option).
• No := += ?= syntax for variable assignment.
• No built-in function available.
• No pattern targets.
• No pattern substitution variables.
• No built-in rules.
• No built-in variables (except the one from environment).
• No conditional directives.

Compilation warnings

With gcc 4.8.2 on Linux Ubuntu 14.04 64-bit :

    prog.c:22:15: warning: return makes integer from pointer without a cast [enabled by default]
    prog.c:23:72: warning: signed and unsigned type in conditional expression [-Wsign-compare]
    prog.c:12:11: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]