Re: Deciphering flags in CXX_FOR_TARGET

[Gabriel Dos Reis <gdr at codesourcery dot com>]

Nathanael Nerode <neroden@doctormoo.dyndns.org> writes:

[...]

| > | > I suspect they're necessary for building libstdc++-v3 or libjava, and
| > | > that the weirdness is actually a bug.
| > | Heh.  Actually, that's the one thing I'm absolutely sure they're not
| > | necessary for, since they're explicitly avoided in those two contexts!
| > 
| > I'm not sure I understand your comment.  Maybe the name of script is
| > ill-choosen but at the time it was first created that name was
| > descriptive. 
| If you look carefully at the top level configure.in, you will note the
| comment 'Don't use libstdc++-v3's flags to configure/build itself.'

That comment is right since the flags output by testsuite_flags do
depend on information passed down from the toplevel configure.in.

| The way the macros are set up explicitly avoids using the flags from the
| testsuite_flags script when the directory being dealt with is 'libjava'
| or 'libstdc++-v3'.  This is presumably because the script doesn't exist
| until libstdc++-v3 is configured.

testsuite_flags is generated from testsuite_flags.in during
libstdc++-v3 configuration.

| Presumably its flags are used for c++ tests,

Mostly.  But any client built at the same time and that needs to
locate V3 headers has to invoke that script in order to get the
correct values.

-- Gaby