Re: Feature request: per-file compilation flags

[Jack Kelly]

On Wed, Mar 31, 2010 at 9:04 AM, Manoj Rajagopalan <address@hidden> wrote:
>   A typical use case for me is when one particular function that resides in a
> file by itself must be compiled without optimizations so that some
> machine-specific numerical information can be calculated accurately. With C++
> the volatile keyword pre-empts this requirement but C and FORTRAN lack this
> capability. So far my option is to create a convenience library for each file
> that requires special compilation flags.

C also has "volatile", with (I thought?) the same semantics: don't
optimise access.

Here's a way to do this in current automake, compiling foo.c into bar
and into baz, but with different flags:

bin_PROGRAMS = bar baz
...
bar_LDADD = libfoo_bar.a
baz_LDADD = libfoo_baz.a

noinst_LIBRARIES = libfoo_bar.a libfoo_baz.a
libfoo_bar_a_SOURCES = foo.c
libfoo_baz_a_SOURCES = foo.c
libfoo_bar_a_CFLAGS = -O3
libfoo_baz_a_CFLAGS = -O0

You'll also need AM_PROG_CC_C_O in configure.ac.

-- Jack