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author | Dimitry Andric <dimitry@andric.com> | 2023-05-03 22:47:12 +0200 |
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committer | Dimitry Andric <dimitry@andric.com> | 2023-05-08 20:29:26 +0200 |
commit | d873966fdeae7f0ac974318ce21772af555f1660 (patch) | |
tree | f41e294f70c296286c3d7a249482ae4134101691 | |
parent | fc4c00b21983ddbe7a5e67e240c40fece4fea285 (diff) | |
download | libgit2-d873966fdeae7f0ac974318ce21772af555f1660.tar.gz |
util: detect all possible qsort_r and qsort_s variants
As reported in https://bugs.freebsd.org/271234, recent versions of
FreeBSD have adjusted the prototype for qsort_r() to match the POSIX
interface. This causes libgit2's CMake configuration check to fail to
detect qsort_r(), making it fall back to qsort_s(), which in libgit2
also has an incompatible interface. With recent versions of clang this
results in a "incompatible function pointer types" compile error.
Summarizing, there are four variations of 'qsort-with-context':
* old style BSD qsort_r(), used in FreeBSD 13 and earlier, where the
comparison function has the context parameter first
* GNU or POSIX qsort_r(), also used in FreeBSD 14 and later, where the
comparison function has the context parameter last
* C11 qsort_s(), where the comparison function has the context parameter
last
* Microsoft qsort_s(), where the comparison function has the context
parameter first
Add explicit detections for all these variants, so they get detected as
(in the same order as above):
* `GIT_QSORT_R_BSD`
* `GIT_QSORT_R_GNU`
* `GIT_QSORT_S_C11`
* `GIT_QSORT_S_MSC`
An additional complication is that on FreeBSD 14 and later, <stdlib.h>
uses the C11 _Generic() macro mechanism to automatically select the
correct qsort_r() prototype, depending on the caller's comparison
function argument. This breaks CMake's check_prototype_definition()
functionality, since it tries to redefine the function, and _Generic
macro is expanded inline causing a compile error.
Work around that problem by putting the function names in parentheses,
to prevent the preprocessor from using a macro to replace the function
name.
Also, in `git__qsort_r()`, change the `#if` order so the variants that
do not have to use glue are preferred.
-rw-r--r-- | src/CMakeLists.txt | 20 | ||||
-rw-r--r-- | src/util/git2_features.h.in | 3 | ||||
-rw-r--r-- | src/util/util.c | 17 |
3 files changed, 29 insertions, 11 deletions
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt index cc0a0d4dc..de591e4e4 100644 --- a/src/CMakeLists.txt +++ b/src/CMakeLists.txt @@ -58,15 +58,29 @@ add_feature_info(futimens GIT_USE_FUTIMENS "futimens support") # qsort +# old-style FreeBSD qsort_r() has the 'context' parameter as the first argument +# of the comparison function: 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 *))" + "void (qsort_r)(void *base, size_t nmemb, size_t size, void *context, int (*compar)(void *, const void *, const void *))" "" "stdlib.h" GIT_QSORT_R_BSD) +# GNU or POSIX qsort_r() has the 'context' parameter as the last argument of the +# comparison function: check_prototype_definition(qsort_r - "void qsort_r(void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *, void *), void *arg)" + "void (qsort_r)(void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *, void *), void *context)" "" "stdlib.h" GIT_QSORT_R_GNU) -check_function_exists(qsort_s GIT_QSORT_S) +# C11 qsort_s() has the 'context' parameter as the last argument of the +# comparison function, and returns an error status: +check_prototype_definition(qsort_s + "errno_t (qsort_s)(void *base, rsize_t nmemb, rsize_t size, int (*compar)(const void *, const void *, void *), void *context)" + "0" "stdlib.h" GIT_QSORT_S_C11) + +# MSC qsort_s() has the 'context' parameter as the first argument of the +# comparison function, and as the last argument of qsort_s(): +check_prototype_definition(qsort_s + "void (qsort_s)(void *base, size_t num, size_t width, int (*compare )(void *, const void *, const void *), void *context)" + "" "stdlib.h" GIT_QSORT_S_MSC) # random / entropy data diff --git a/src/util/git2_features.h.in b/src/util/git2_features.h.in index 1575be641..5f606df84 100644 --- a/src/util/git2_features.h.in +++ b/src/util/git2_features.h.in @@ -26,7 +26,8 @@ #cmakedefine GIT_QSORT_R_BSD #cmakedefine GIT_QSORT_R_GNU -#cmakedefine GIT_QSORT_S +#cmakedefine GIT_QSORT_S_C11 +#cmakedefine GIT_QSORT_S_MSC #cmakedefine GIT_SSH 1 #cmakedefine GIT_SSH_MEMORY_CREDENTIALS 1 diff --git a/src/util/util.c b/src/util/util.c index 9c9f2c040..f4eaf5835 100644 --- a/src/util/util.c +++ b/src/util/util.c @@ -18,7 +18,7 @@ # endif # include <windows.h> -# ifdef GIT_QSORT_S +# ifdef GIT_QSORT_S_MSC # include <search.h> # endif #endif @@ -673,7 +673,7 @@ size_t git__unescape(char *str) return (pos - str); } -#if defined(GIT_QSORT_S) || defined(GIT_QSORT_R_BSD) +#if defined(GIT_QSORT_S_MSC) || defined(GIT_QSORT_R_BSD) typedef struct { git__sort_r_cmp cmp; void *payload; @@ -690,7 +690,8 @@ static int GIT_LIBGIT2_CALL git__qsort_r_glue_cmp( #if !defined(GIT_QSORT_R_BSD) && \ !defined(GIT_QSORT_R_GNU) && \ - !defined(GIT_QSORT_S) + !defined(GIT_QSORT_S_C11) && \ + !defined(GIT_QSORT_S_MSC) static void swap(uint8_t *a, uint8_t *b, size_t elsize) { char tmp[256]; @@ -721,12 +722,14 @@ static void insertsort( void git__qsort_r( void *els, size_t nel, size_t elsize, git__sort_r_cmp cmp, void *payload) { -#if defined(GIT_QSORT_R_BSD) +#if defined(GIT_QSORT_R_GNU) + qsort_r(els, nel, elsize, cmp, payload); +#elif defined(GIT_QSORT_S_C11) + qsort_s(els, nel, elsize, cmp, payload); +#elif defined(GIT_QSORT_R_BSD) git__qsort_r_glue glue = { cmp, payload }; qsort_r(els, nel, elsize, &glue, git__qsort_r_glue_cmp); -#elif defined(GIT_QSORT_R_GNU) - qsort_r(els, nel, elsize, cmp, payload); -#elif defined(GIT_QSORT_S) +#elif defined(GIT_QSORT_S_MSC) git__qsort_r_glue glue = { cmp, payload }; qsort_s(els, nel, elsize, git__qsort_r_glue_cmp, &glue); #else |