Hi Bruno, Bruno Haible <br...@clisp.org> writes:
> modules/ieee754-h is simpler, with a use of _GL_GNULIB_HEADER that is > effectively replaced with 1 on the gnulib side. But this works only if > there are no other substitutions to be made (no @...@ replacements) > in preprocessor lines. (I would not bet that code like this: > #if 0 > # if @FOOBAR@ > # endif > #endif > works for all C and C++ compilers. Better avoid that.) I always wondered if a compiler would fail with that. As far as I remember gcc and clang handle it fine. But I agree it is best to avoid to be safe (and since it would be ugly in an installed header). > In any case, the ieee754-h approach is not to think "let's look at the > gnulib .in.h file and see how we can adapt it for glibc" but instead > "let's create a well-formed .h file for glibc and then let's see how we > can massage it so that it works with gnulib". > > The latter approach leads me to the following patch (that should work > when the header is installed in /usr/include and even with "gcc -Wundef"): Makes sense. Thanks! Collin
