gcc/g++ compiler options

March 5, 2010

When I started using C in CS137, one of the tips I picked up on was passing options to the compiler to request warnings. This usually meant having to type a long line of options every time I wanted to compile something. Additionally, I wasn’t a big fan of the a.out default filenames, so I wanted to specify my own.

So I borrowed and modified a quick Perl script to do this for me: it takes the source code as the argument, and runs gcc on it, with all my favourite options passed to the compiler.

#!/usr/bin/perl

my $output = $ARGV[0];
$output =~ s/(.*)\.c$/$1/;

exec("/usr/bin/gcc @ARGV -o $output -std=c99 -lm -Wall -W -pedantic");

This takes my source file, runs gcc on it with arguments to use the C99 standard, enable warnings, and give the compiled file the same name as the source (without the .c extension).

I saved this as gcc2, changed the permissions so it’d be executable, and added this line to .bash_login:

alias gcc2="/Users/mhyee/gcc2";

This allows me to simply type gcc2 source.c without the entire path.

Now that we’ve moved to C++ in CS138, I did the same thing for compiling C++ files.

#!/usr/bin/perl

my $output = $ARGV[0];
$output =~ s/(.*)\.(C|cc|cpp|c\+\+|cp|cxx)$/$1/;

exec("/usr/bin/g++ @ARGV -o $output -pedantic -Wall -Wextra -ansi");

This is similar to gcc2 except that it’s for g++ and the regex strips out a wider variety of extensions. I called this file gpp and added the line to .bash_login:

alias gpp="/Users/mhyee/gpp";

Once again, I can type gpp source.cc without worrying about the entire path or arguments.

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