During an exp-run for llvm 16 (see bug 271047), it turned out that devel/libgit2 failed to build with clang 16: /wrkdirs/usr/ports/devel/libgit2/work/libgit2-1.5.2/src/util/util.c:731:28: error: incompatible function pointer types passing 'int (void *, const void *, const void *)' to parameter of type 'int (*)(const void *, const void *, void *)' [-Wincompatible-function-pointer-types] qsort_s(els, nel, elsize, git__qsort_r_glue_cmp, &glue); ^~~~~~~~~~~~~~~~~~~~~ /usr/include/stdlib.h:397:11: note: passing argument to parameter here int (*)(const void *, const void *, void *), void *); ^ Clang is indeed right, as the version of qsort_s(3) in FreeBSD 13 and later has the 'void *payload' parameter last: errno_t qsort_s(void *, rsize_t, rsize_t, int (*)(const void *, const void *, void *), void *); This could be fixed by putting the arguments in the right place for qsort_s(3), but it turns out the rabbit hole goes a bit deeper: on 14-CURRENT, libgit2's CMake configuration is not able to detect qsort_r(3), which is actually why it chooses qsort_s(): -- Checking prototype qsort_r for GIT_QSORT_R_BSD -- Checking prototype qsort_r for GIT_QSORT_R_BSD - False -- Checking prototype qsort_r for GIT_QSORT_R_GNU -- Checking prototype qsort_r for GIT_QSORT_R_GNU - False -- Looking for qsort_s -- Looking for qsort_s - found The problem with the GIT_QSORT_R_BSD detection is due to the check in libgit2's src/CMakeLists.txt, where it does: check_prototype_definition(qsort_r "void qsort_r(void *base, size_t nmemb, size_t size, void *thunk, int (*compar)(void *, const void *, const void *))" "" "stdlib.h" GIT_QSORT_R_BSD) and CMake attempts to define a function with a similar prototype in its test program, which then fails to compile, at least on 14-CURRENT: /wrkdirs/share/dim/ports/devel/libgit2/work/.build/CMakeFiles/CMakeScratch/TryCompile-tILE28/CheckPrototypeDefinition.c:14:6: error: expected identifier or '(' void qsort_r(void *base, size_t nmemb, size_t size, void *thunk, int (*compar)(void *, const void *, const void *)) { ^ /usr/include/stdlib.h:357:5: note: expanded from macro 'qsort_r' __generic(arg5, int (*)(void *, const void *, const void *), \\ ^ /usr/include/sys/cdefs.h:323:2: note: expanded from macro '__generic' _Generic(expr, t: yes, default: no) ^ This is because in https://cgit.freebsd.org/src/commit/?id=af3c78886fd8d Ed Schouten changed the prototype of qsort_r(3) to match POSIX, using a C11 _Generic macro. When CMake tries to compile its own custom definition of qsort_r, that fails with the above compile error, because the macro gets expanded in place of the function declaration. So the summarized situation is: * On 12.x and 13.x, qsort_r(3) is a plain function, and uses the old comparison function type: 'int (*compar)(void *thunk, const void *elem1, const void *elem2)'. Therefore, CMake detects GIT_QSORT_R_BSD, and libgit2's src/util/util.c uses the correct comparison function type. * On 14.x, qsort_r(3) is a macro, and uses the POSIX comparison function type: 'int (*compar)(const void *elem1, const void *elem2, void *thunk)'. Therefore, CMake fails to detect GIT_QSORT_R_BSD, and detects GIT_QSORT_S instead, and libgit2's src/util/util.c uses an incorrect comparison function type. Possible fixes include: * Adding __FreeBSD_version check, although base commit af3c78886fd8d did not bump the version * Adding additional CMake logic to correctly work around the _Generic macro definition in 14.x's stdlib.h * Fixing CMake's check_prototype_definition() <https://cmake.org/cmake/help/latest/module/CheckPrototypeDefinition.html> to put parentheses around the checked function names * ... haven't thought or more possible fixes here, suggestions welcome Preferably, any fix should be upstreamable.
Submitted pull request upstream: https://github.com/libgit2/libgit2/pull/6555
Created attachment 242064 [details] devel/libgit2: fix build with clang 16 Adjusted https://github.com/libgit2/libgit2/pull/6555 to apply on top of libgit-1.5.2.
(In reply to Dimitry Andric from comment #2) Thanks a lot for taking care of this! If a finished solution is accepted upstream we can directly include it or wait for a new release, both options are find for me.
Created attachment 242162 [details] devel/libgit2: fix build with clang 16 Upstream merged my original pull request, but then another problem turned up which was addressed in https://github.com/libgit2/libgit2/pull/6558, and eventually upstream landed the following commits: * https://github.com/libgit2/libgit2/commit/d873966fd (util: detect all possible qsort_r and qsort_s variants) * https://github.com/libgit2/libgit2/commit/3d9cb5e0c (Work around -Werror problems when detecting qsort variants) * https://github.com/libgit2/libgit2/commit/767a9a733 (cmake: simplify QSORT names) * https://github.com/libgit2/libgit2/commit/333573857 (cmake: refactor `check_prototype_definition`) This new patch combines all of the above, with some adjustments for libgit-1.5.2.
Thanks a lot, please feel free to commit it!
A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/ports/commit/?id=a62f1b5796b641bb502b33f7f073238a49dc4d0c commit a62f1b5796b641bb502b33f7f073238a49dc4d0c Author: Dimitry Andric <dim@FreeBSD.org> AuthorDate: 2023-05-14 12:26:37 +0000 Commit: Dimitry Andric <dim@FreeBSD.org> CommitDate: 2023-05-14 19:23:31 +0000 devel/libgit2: fix build with clang 16 Clang 16 has a new error about incompatible function types, which shows up when building devel/libgit2: /wrkdirs/usr/ports/devel/libgit2/work/libgit2-1.5.2/src/util/util.c:731:28: error: incompatible function pointer types passing 'int (void *, const void *, const void *)' to parameter of type 'int (*)(const void *, const void *, void *)' [-Wincompatible-function-pointer-types] qsort_s(els, nel, elsize, git__qsort_r_glue_cmp, &glue); ^~~~~~~~~~~~~~~~~~~~~ /usr/include/stdlib.h:397:11: note: passing argument to parameter here int (*)(const void *, const void *, void *), void *); ^ Clang is indeed right, as the version of qsort_s(3) in FreeBSD 13 and later has the 'void *payload' parameter last: errno_t qsort_s(void *, rsize_t, rsize_t, int (*)(const void *, const void *, void *), void *); This could be fixed by putting the arguments in the right place for qsort_s(3), but it turns out the rabbit hole goes a bit deeper: on 14-CURRENT, libgit2's CMake configuration is not able to detect qsort_r(3), which is actually why it chooses qsort_s(): -- Checking prototype qsort_r for GIT_QSORT_R_BSD -- Checking prototype qsort_r for GIT_QSORT_R_BSD - False -- Checking prototype qsort_r for GIT_QSORT_R_GNU -- Checking prototype qsort_r for GIT_QSORT_R_GNU - False -- Looking for qsort_s -- Looking for qsort_s - found The problem with the GIT_QSORT_R_BSD detection is due to the check in libgit2's src/CMakeLists.txt, where it does: check_prototype_definition(qsort_r "void qsort_r(void *base, size_t nmemb, size_t size, void *thunk, int (*compar)(void *, const void *, const void *))" "" "stdlib.h" GIT_QSORT_R_BSD) and CMake attempts to define a function with a similar prototype in its test program, which then fails to compile, at least on 14-CURRENT: /wrkdirs/share/dim/ports/devel/libgit2/work/.build/CMakeFiles/CMakeScratch/TryCompile-tILE28/CheckPrototypeDefinition.c:14:6: error: expected identifier or '(' void qsort_r(void *base, size_t nmemb, size_t size, void *thunk, int (*compar)(void *, const void *, const void *)) { ^ /usr/include/stdlib.h:357:5: note: expanded from macro 'qsort_r' __generic(arg5, int (*)(void *, const void *, const void *), \\ ^ /usr/include/sys/cdefs.h:323:2: note: expanded from macro '__generic' _Generic(expr, t: yes, default: no) ^ This is because in https://cgit.freebsd.org/src/commit/?id=af3c78886fd8d Ed Schouten changed the prototype of qsort_r(3) to match POSIX, using a C11 _Generic macro. When CMake tries to compile its own custom definition of qsort_r, that fails with the above compile error, because the macro gets expanded in place of the function declaration. So the summarized situation is: * On 12.x and 13.x, qsort_r(3) is a plain function, and uses the old comparison function type: 'int (*compar)(void *thunk, const void *elem1, const void *elem2)'. Therefore, CMake detects GIT_QSORT_R_BSD, and libgit2's src/util/util.c uses the correct comparison function type. * On 14.x, qsort_r(3) is a macro, and uses the POSIX comparison function type: 'int (*compar)(const void *elem1, const void *elem2, void *thunk)'. Therefore, CMake fails to detect GIT_QSORT_R_BSD, and detects GIT_QSORT_S instead, and libgit2's src/util/util.c uses an incorrect comparison function type. I submitted https://github.com/libgit2/libgit2/pull/6555 and https://github.com/libgit2/libgit2/pull/6558 upstream to remedy the situation and correctly detect all qsort variants, and these were merged with a few minor changes. This is an adjusted version of the upstream commits that applies on top of libgit-1.5.2. PR: 271234 Approved by: mfechner (maintainer) MFH: 2023Q2 devel/libgit2/Makefile | 1 + devel/libgit2/files/patch-github-pr6555 (new) | 145 ++++++++++++++++++++++++++ 2 files changed, 146 insertions(+)