AOSP: lib/support: don't assume qsort_r() is always available on Linux

Since commit 4e5f24ae4267 ("Use an autoconf test to detect for a BSD- or
GNU-style qsort_r function"), e2fsck fails to build for Android because
lib/support/sort_r.h assumes that qsort_r() is always available on
"Linux", but in fact it's not supported by Android's libc.

Rename _SORT_R_LINUX to _SORT_R_GNU to clarify that it's really the
glibc convention for qsort_r(), not the "Linux" convention per se, and
make sort_r.h stop setting it automatically when __linux__ is defined.

Note: this change does *not* prevent glibc's qsort_r() from being used
when e2fsprogs is built using the autotools-based build system, as
'configure' checks for qsort_r() too.  This change just affects the
fallback behavior for when qsort_r() was not already detected.

Fixes: 4e5f24ae4267 ("Use an autoconf test to detect for a BSD- or GNU-style qsort_r function")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20230130215829.863455-1-ebiggers@kernel.org
Change-Id: I4ed2fd6aef5a0d62960988d29e35acd337bb7d02
From AOSP commit: 9f289d0add4f12fa2e4b21754141363a2759d152

diff --git a/lib/support/sort_r.h b/lib/support/sort_r.h
index ebf78378eb786b4921182ebb63006b6ddc25472a..8473ca8342e46744e3b242ba89ef2b6bfa0b6d65 100644 (file)
--- a/lib/support/sort_r.h
+++ b/lib/support/sort_r.h
@@ -25,12 +25,12 @@ void sort_r(void *base, size_t nel, size_t width,
 #define _SORT_R_INLINE inline
 
 #if (defined HAVE_GNU_QSORT_R)
-#  define _SORT_R_LINUX
+#  define _SORT_R_GNU
 #elif (defined HAVE_BSD_QSORT_R)
 #  define _SORT_R_BSD
 #elif (defined __gnu_hurd__ || defined __GNU__ || \
-       defined __linux__ || defined __MINGW32__ || defined __GLIBC__)
-#  define _SORT_R_LINUX
+       defined __MINGW32__ || defined __GLIBC__)
+#  define _SORT_R_GNU
 #elif (defined __APPLE__ || defined __MACH__ || defined __DARWIN__ || \
      defined __FreeBSD__ || defined __DragonFly__)
 #  define _SORT_R_BSD
@@ -264,7 +264,7 @@ static _SORT_R_INLINE void sort_r_simple(void *base, size_t nel, size_t w,
 
   #endif
 
-  #if defined _SORT_R_LINUX
+  #if defined _SORT_R_GNU
 
     typedef int(* __compar_d_fn_t)(const void *, const void *, void *);
     extern void qsort_r(void *base, size_t nel, size_t width,
@@ -280,7 +280,7 @@ static _SORT_R_INLINE void sort_r_simple(void *base, size_t nel, size_t w,
                                                   const void *_b, void *_arg),
                                     void *arg)
   {
-    #if defined _SORT_R_LINUX
+    #if defined _SORT_R_GNU
 
       #if defined __GLIBC__ && ((__GLIBC__ < 2) || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 8))
 
@@ -319,7 +319,7 @@ static _SORT_R_INLINE void sort_r_simple(void *base, size_t nel, size_t w,
 
 #undef _SORT_R_INLINE
 #undef _SORT_R_WINDOWS
-#undef _SORT_R_LINUX
+#undef _SORT_R_GNU
 #undef _SORT_R_BSD
 
 #endif /* SORT_R_H_ */