Hi, Mathieu Othacehe <m.othac...@gmail.com> skribis:
>> So is it expected that C_INCLUDE_PATH comes before the hard-coded GCC >> include directory? How can we work around that? > > Turns out, the best source of documentation here is > gcc/incpath.c. Here's a summary of my understanding. > > Header search list: > > * QUOTE > -> -iquote > * BRACKET > -> -I goes here > -> CPATH goes here > * SYSTEM > -> -isystem goes here > -> C_INCLUDE_PATH goes here > -> Hardcoded includes (gcc + glibc) goes here > * AFTER > -> -idirafter goes here. > > Duplicates inside SYSTEM are deleted, the first occurence is kept. So as > long as we have glibc in C_INCLUDE_PATH it will trigger deletion of > glibc in hardcoded includes and AFTER section. > > So I can see only two solutions here. > > 1. Go back to using CPATH (sad!), because when there is duplication > between BRACKET and SYSTEM, the include from SYSTEM is kept (why it > works on master). > > 2. Find a way to remove glibc from C_INCLUDE_PATH, but I have no clue > how to do this properly. Maybe using some kind of filter on > search-path-specifications. I’d rather go for #2. To do that, we could modify the ‘set-paths’ phase to manually remove glibc from C_INCLUDE_PATH (fragile), or we could modify GCC (perhaps removing the ‘remove_duplicates’ call for SYSTEM). Either way, this wouldn’t work well with ‘guix environment’, where glibc ends up in /gnu/store/…-profile, so it does not appear as duplicate to GCC. On ‘core-updates’, I see: --8<---------------cut here---------------start------------->8--- $ git log | head -3 commit 5afcb5caa53615c0a432e0c1781155398d747218 Author: Ludovic Courtès <l...@gnu.org> Date: Sat Feb 22 21:39:27 2020 +0100 $ ./pre-inst-env guix environment -C -e '(@@ (gnu packages commencement) coreutils-final)' [env]$ gcc -v -x c -E /dev/null Using built-in specs. COLLECT_GCC=gcc Target: x86_64-unknown-linux-gnu Configured with: Thread model: posix gcc version 7.5.0 (GCC) COLLECT_GCC_OPTIONS='-v' '-E' '-mtune=generic' '-march=x86-64' /gnu/store/0pjrnr8vhp94ykvarysd9wg7hcvfqkl5-gcc-7.5.0/libexec/gcc/x86_64-unknown-linux-gnu/7.5.0/cc1 -E -quiet -v /dev/null -mtune=generic -march=x86-64 ignoring duplicate directory "/gnu/store/k9l4v4530p1a69j8qs0aijbmn8lwak20-profile/include" ignoring nonexistent directory "/no-gcc-local-prefix/include" ignoring nonexistent directory "/gnu/store/adrw71v03nawqwyblxc0mdhcc41j5vnn-gcc-7.5.0-lib/lib/gcc/x86_64-unknown-linux-gnu/7.5.0/../../../../../../../x86_64-unknown-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /gnu/store/k9l4v4530p1a69j8qs0aijbmn8lwak20-profile/include /gnu/store/adrw71v03nawqwyblxc0mdhcc41j5vnn-gcc-7.5.0-lib/lib/gcc/x86_64-unknown-linux-gnu/7.5.0/include /gnu/store/adrw71v03nawqwyblxc0mdhcc41j5vnn-gcc-7.5.0-lib/lib/gcc/x86_64-unknown-linux-gnu/7.5.0/include-fixed /gnu/store/ccjj5wg0qkjs1zfjr98nhb8cpr434izw-glibc-2.31/include End of search list. # 1 "/dev/null" # 1 "<built-in>" # 1 "<command-line>" # 31 "<command-line>" # 1 "/gnu/store/k9l4v4530p1a69j8qs0aijbmn8lwak20-profile/include/stdc-predef.h" 1 3 # 32 "<command-line>" 2 # 1 "/dev/null" COMPILER_PATH=/gnu/store/0pjrnr8vhp94ykvarysd9wg7hcvfqkl5-gcc-7.5.0/libexec/gcc/x86_64-unknown-linux-gnu/7.5.0/:/gnu/store/0pjrnr8vhp94ykvarysd9wg7hcvfqkl5-gcc-7.5.0/libexec/gcc/x86_64-unknown-linux-gnu/7.5.0/:/gnu/store/0pjrnr8vhp94ykvarysd9wg7hcvfqkl5-gcc-7.5.0/libexec/gcc/x86_64-unknown-linux-gnu/:/gnu/store/adrw71v03nawqwyblxc0mdhcc41j5vnn-gcc-7.5.0-lib/lib/gcc/x86_64-unknown-linux-gnu/7.5.0/:/gnu/store/adrw71v03nawqwyblxc0mdhcc41j5vnn-gcc-7.5.0-lib/lib/gcc/x86_64-unknown-linux-gnu/ LIBRARY_PATH=/gnu/store/k9l4v4530p1a69j8qs0aijbmn8lwak20-profile/lib/:/gnu/store/k9l4v4530p1a69j8qs0aijbmn8lwak20-profile/lib/:/gnu/store/adrw71v03nawqwyblxc0mdhcc41j5vnn-gcc-7.5.0-lib/lib/gcc/x86_64-unknown-linux-gnu/7.5.0/:/gnu/store/adrw71v03nawqwyblxc0mdhcc41j5vnn-gcc-7.5.0-lib/lib/gcc/x86_64-unknown-linux-gnu/7.5.0/../../../:/gnu/store/ccjj5wg0qkjs1zfjr98nhb8cpr434izw-glibc-2.31/lib COLLECT_GCC_OPTIONS='-v' '-E' '-mtune=generic' '-march=x86-64' --8<---------------cut here---------------end--------------->8--- Looking at ‘cppdefault.c’ in GCC, I don’t see where glibc-2.31/include comes from; it seems that ‘INCLUDE_DEFAULTS’ is undefined on glibc systems. Thoughts? Incidentally, do we have problems building anything other than QEMU? Thanks, Ludo’.
