Hello commit 57a889b7282dab303c4cdc49cccbbe22f961bd1c: commit 57a889b7282dab303c4cdc49cccbbe22f961bd1c Author: Jonas Hahnfeld <hah...@hahnjo.de> Date: Thu Feb 22 22:09:42 2024 +0100
build: Fix cross-compilation in out-of-tree-builds gen-scmconfig.h is generated in libguile, not $(top_builddir). * libguile/Makefile.am: Add '-I.' when compiling gen-scmconfig.o. Signed-off-by: Ludovic Court<C3><A8>s <l...@gnu.org> was in response to the report quoted here: https://lists.gnu.org/archive/html/bug-guile/2024-05/msg00006.html (apologies for not replying inside the original mail thread: I was not subscribed at the time) But, paradoxically, for me it breaks cross compilation of 32 bit target on a 64 bit native host. After successful build/install of guile-3.0.10 for the native host (64 bit), I run the cross build with: --build=x86_64-unknown-linux-gnu --host=i686-unknown-linux-gnu and get: ----8<---- make[2]: Entering directory '/home/balducci/tmp/install-us-d/guile-3.0.10.d/guile-3.0.10/libguile' \ if [ "yes" = "yes" ]; then \ gcc -m32 -DHAVE_CONFIG_H -I.. \ -I. -c -o gen-scmconfig.o gen-scmconfig.c; \ else \ gcc -m32 -DHAVE_CONFIG_H -DBUILDING_LIBGUILE=1 -I.. -I.. -I../lib -I../lib -iquote. -I../libguile/lightening -I/home/balducci/tmp/install-us-d/guile-3.0.10.d/guile-3.0.10 -Wall -Wmissing-prototypes -Wpointer-arith -fno-strict-aliasing -fwrapv -fvisibility=hidden -I/opt/stow.d/versions/gc-5458/usr/include -Wno-incompatible-pointer-types -flto -c -o gen-scmconfig.o gen-scmconfig.c; \ fi In file included from ../libguile/inline.h:28, from ../libguile/gc.h:25, from ./strings.h:25, from /usr/include/string.h:462, from gen-scmconfig.c:142: ../libguile/scm.h:30:10: fatal error: libguile/scmconfig.h: No such file or directory 30 | #include "libguile/scmconfig.h" | ^~~~~~~~~~~~~~~~~~~~~~ compilation terminated. make[2]: *** [Makefile:4478: gen-scmconfig.o] Error 1 make[2]: Leaving directory '/home/balducci/tmp/install-us-d/guile-3.0.10.d/guile-3.0.10/libguile' ---->8---- The reason seems to be precisely the "-I." added by the above mentioned commit. If I delete the "-I." directive the cross build completes successfully. Actually, in my case, the reason why the "-I." causes the failure is the following. libguile/gen-scmconfig.c includes the string.h system header: #include <string.h> On my system (GNU/linux) the /usr/include/string.h system header (from glibc) includes a strings.h system header (note the s in strings.h): #include <strings.h> It happens that in libguile, where gen-scmconfig.c is compiled, there is also a strings.h header of the guile distribution (so totally different from the system's /usr/include/strings.h): thus, the added "-I." directive makes my /usr/include/string.h system header include *guile's strings.h*, instead of my system's /usr/include/strings.h and this causes the compile failure, due to the (wrong) chain of included headers downstream, which ends up trying to include libguile/scmconfig.h, which, obviously, isn't there yet, since it is supposed to be created precisely by the gen-scmconfig executable. As I could clarify, the wrong inclusion chain caused by the "-I." directive is: gen-scmconfig.c `-- /usr/include/string.h # THIS WANTS /usr/include/strings.h `-- ./strings.h # BUT GETS THIS ONE, INSTEAD `-- ../libguile/gc.h `-- ../libguile/inline.h `-- ../libguile/scm.h `-- ../libguile/scmconfig.h # ISN'T THERE, YET => ERROR According to the original post (which then triggered the above mentioned commit) the "-I." directive was supposed to fix the inclusion of gen-scmconfig.h, which is created in the same directory (libguile) where gen-scmconfig.c is compiled. BUT: gen-scmconfig.c includes gen-scmconfig.h as a *quoted* header: #include "gen-scmconfig.h" and, at least with gcc, which I use for building, quoted headers are looked for in the same directory of the file being compiled without the need for a "-I." directive (OTOH, the "-I." directive makes the current directory searched for headers BEFORE the system directories, and this causes the build failure in my case, as detailed above). Turning the "-I." into "-iquote." or "-idirafter." (instead of deleting it) works for me and maybe might work also for the original poster, but I don't think is portable outside gcc... Apologies for the long mail: I hope to have clarified the problem thanks a lot for your valuable work ciao -gabriele