GNU toolchain configuration

Variables you may want to tweak:

• GENERATE_COVERAGE if set, adds SPECIAL_CFLAGS to generate coverage

  data for gcov.

• CC, CPP, CXX, AR, AS, The commands to use. Each compilter suite configuration

  LD, OBJDUMP is expected to set these.

• LDFLAGS Mandatory libraries to include when linking the final

  executable. LDFLAGS gets tacked onto the end of the link command-line.

• WFLAGS C-compiler warning flags.

• ARFLAGS Flags to the archiver command when creating link libraries.

• OPTIMIZE_CFLAGS Optimization options to the C compiler.

• CFLAGS, CXXFLAGS The flags that appear on the C and C++ compiler commandline,

  respectively. Typically '%WFLAGS %SPECIAL_CFLAGS %OPTIMIZE_CFLAGS' or similar.

We also use Devel::Depend::Cpp as our depender.