On 11/20/18 7:11 PM, Joseph Myers wrote: > On Tue, 20 Nov 2018, Jakub Jelinek wrote: > >> hardcoding /usr/include looks just very wrong here. That should always be >> dependent on the configured prefix or better be relative from the driver, >> gcc should be relocatable. Or at least come from configure. It should e.g. >> honor the sysroot stuff etc. >> >> That said, I think you need somebody familiar with the driver, perhaps >> Joseph?
Hi Joseph. > > I'd sort of expect structures like those in cppdefault.[ch] to describe > the relevant Fortran directories and their properties (such as being > sysrooted or not - and if sysrooted, I suppose you'll want to make sure > SYSROOT_HEADERS_SUFFIX_SPEC is properly applied). We probably forgot to mention that the search mechanism happens in GCC driver. It's because we want to include the file (via a Fortran -fpre-include) conditionally only when found. > > If this preinclude doesn't pass through the C preprocessor, directories in > which it is searched for will need multilib or multiarch suffixes. No, it's not C preprocessor. > (Multilib suffixes on include directories for C are more or less an > implementation detail of how fixed headers are arranged in the case where > sysroot headers suffixes are used; they aren't really expected to be a > stable interface such that third-party software might install anything > using them, but I'm not sure if this preinclude is meant to come from > external software or be installed by GCC. It will come from glibc-devel package, and it's expected to be installed in: usr/include/finclude/ for 64-bit header and /usr/include/finclude/32/ for the 32-bit header. Multiarch suffixes, for systems > using Debian/Ubuntu-style multiarch directory arrangements, *are* intended > as a stable interface. And multilib *OS* suffixes > (-print-multi-os-directory) are a stable interface, but only really > suitable for libraries, not headers, because they are paths relative to > lib/ such as ../lib64.) If I understand correctly, Jakub wanted to have it working with -m32 being used for 64-bit GCC compiler. So yes, multi os for header files. So the question is what can we really do in the GCC driver? Martin
