Use an autoconf test to detect for a BSD- or GNU-style qsort_r function

BSD is planning on changing their qsort_r() implementation to align
with the POSIX/GNU-style qsort_r() function signature.  So use an
autoconf test to determine which qsort_r() a system has.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

5 files changed, 218 insertions, 25 deletions

diff --git a/configure b/configure
index 493542367..caf6661df 100755
--- a/configure
+++ b/configure
@@ -13270,6 +13270,12 @@ then :
   printf "%s\n" "#define HAVE_PWRITE64 1" >>confdefs.h
 
 fi
+ac_fn_c_check_func "$LINENO" "qsort_r" "ac_cv_func_qsort_r"
+if test "x$ac_cv_func_qsort_r" = xyes
+then :
+  printf "%s\n" "#define HAVE_QSORT_R 1" >>confdefs.h
+
+fi
 ac_fn_c_check_func "$LINENO" "secure_getenv" "ac_cv_func_secure_getenv"
 if test "x$ac_cv_func_secure_getenv" = xyes
 then :
@@ -13951,6 +13957,90 @@ fi
 fi
 fi
 
+if test "$ac_cv_func_qsort_r" != no
+then :
+
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether qsort_r is GNU version" >&5
+printf %s "checking whether qsort_r is GNU version... " >&6; }
+if test ${e2_cv_gnu_qsort_r+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#include <stdlib.h>
+void (qsort_r)(void *base, size_t nmemb, size_t size,
+	    int (*compar)(const void *, const void *, void *),
+	    void *arg);
+
+int
+main (void)
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  e2_cv_gnu_qsort_r=yes
+else $as_nop
+  e2_cv_gnu_qsort_r=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $e2_cv_gnu_qsort_r" >&5
+printf "%s\n" "$e2_cv_gnu_qsort_r" >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether qsort_r is BSD version" >&5
+printf %s "checking whether qsort_r is BSD version... " >&6; }
+if test ${e2_cv_bsd_qsort_r+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#include <stdlib.h>
+void (qsort_r)(void *base, size_t nmemb, size_t size,
+	     void *arg, int (*compar)(void *, const void *, const void *));
+
+int
+main (void)
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  e2_cv_bsd_qsort_r=yes
+else $as_nop
+  e2_cv_bsd_qsort_r=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $e2_cv_bsd_qsort_r" >&5
+printf "%s\n" "$e2_cv_bsd_qsort_r" >&6; }
+  case "$e2_cv_gnu_qsort_r:$e2_cv_bsd_qsort_r" in #(
+  yes:no) :
+
+    printf "%s\n" "#define HAVE_GNU_QSORT_R 1" >>confdefs.h
+
+   ;; #(
+  no:yes) :
+
+    printf "%s\n" "#define HAVE_BSD_QSORT_R 1" >>confdefs.h
+
+   ;; #(
+  *) :
+     ;;
+esac
+
+fi
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for unified diff option" >&5
 printf %s "checking for unified diff option... " >&6; }
 if diff -u $0 $0 > /dev/null 2>&1 ; then
diff --git a/configure.ac b/configure.ac
index 78f71fd8e..4ece83e9b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1226,6 +1226,7 @@ AC_CHECK_FUNCS(m4_flatten([
 	pwrite
 	pread64
 	pwrite64
+	qsort_r
 	secure_getenv
 	setmntent
 	setresgid
@@ -1351,6 +1352,33 @@ then
 fi
 AC_SUBST(SEM_INIT_LIB)
 dnl
+dnl qsort_r detection
+dnl
+AS_IF([test "$ac_cv_func_qsort_r" != no], [
+  AC_CACHE_CHECK(whether qsort_r is GNU version, e2_cv_gnu_qsort_r,
+    [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+@%:@include <stdlib.h>
+void (qsort_r)(void *base, size_t nmemb, size_t size,
+	    int (*compar)(const void *, const void *, void *),
+	    void *arg);
+]], [[ ]])],[e2_cv_gnu_qsort_r=yes],[e2_cv_gnu_qsort_r=no])
+  ])
+  AC_CACHE_CHECK(whether qsort_r is BSD version, e2_cv_bsd_qsort_r,
+    [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+@%:@include <stdlib.h>
+void (qsort_r)(void *base, size_t nmemb, size_t size,
+	     void *arg, int (*compar)(void *, const void *, const void *));
+]], [[ ]])],[e2_cv_bsd_qsort_r=yes],[e2_cv_bsd_qsort_r=no])
+  ])
+  AS_CASE("$e2_cv_gnu_qsort_r:$e2_cv_bsd_qsort_r",
+  [yes:no], [
+    AC_DEFINE(HAVE_GNU_QSORT_R, 1, [ Define to 1 if you have the GNU-style 'qsort_r' function.])
+  ],
+  [no:yes], [
+    AC_DEFINE(HAVE_BSD_QSORT_R, 1, [ Define to 1 if you have the BSD-style 'qsort_r' function.])
+  ])
+])
+dnl
 dnl Check for unified diff
 dnl
 AC_MSG_CHECKING(for unified diff option)
diff --git a/e2fsck/rehash.c b/e2fsck/rehash.c
index 210cfdf2f..c79a5acf9 100644
--- a/e2fsck/rehash.c
+++ b/e2fsck/rehash.c
@@ -1053,13 +1053,11 @@ retry_nohash:
 	/* Sort the list */
 resort:
 	if (fd.compress && fd.num_array > 1)
-		sort_r_simple(fd.harray+2, fd.num_array-2,
-			      sizeof(struct hash_entry),
-			      hash_cmp, &name_cmp_ctx);
+		sort_r(fd.harray+2, fd.num_array-2, sizeof(struct hash_entry),
+		       hash_cmp, &name_cmp_ctx);
 	else
-		sort_r_simple(fd.harray, fd.num_array,
-			      sizeof(struct hash_entry),
-			      hash_cmp, &name_cmp_ctx);
+		sort_r(fd.harray, fd.num_array, sizeof(struct hash_entry),
+		       hash_cmp, &name_cmp_ctx);
 
 	/*
 	 * Look for duplicates
diff --git a/lib/config.h.in b/lib/config.h.in
index b5856bb57..6cf1f47db 100644
--- a/lib/config.h.in
+++ b/lib/config.h.in
@@ -55,6 +55,9 @@
 /* Define to 1 if blkid has blkid_topology_get_dax */
 #undef HAVE_BLKID_TOPOLOGY_GET_DAX
 
+/* Define to 1 if you have the BSD-style 'qsort_r' function. */
+#undef HAVE_BSD_QSORT_R
+
 /* Define to 1 if you have the Mac OS X function
    CFLocaleCopyPreferredLanguages in the CoreFoundation framework. */
 #undef HAVE_CFLOCALECOPYPREFERREDLANGUAGES
@@ -154,6 +157,9 @@
 /* Define if the GNU gettext() function is already present or preinstalled. */
 #undef HAVE_GETTEXT
 
+/* Define to 1 if you have the GNU-style 'qsort_r' function. */
+#undef HAVE_GNU_QSORT_R
+
 /* Define if you have the iconv() function and it works. */
 #undef HAVE_ICONV
 
@@ -220,12 +226,12 @@
 /* Define to 1 if you have the `memalign' function. */
 #undef HAVE_MEMALIGN
 
-/* Define to 1 if you have the <memory.h> header file. */
-#undef HAVE_MEMORY_H
-
 /* Define to 1 if you have the `mempcpy' function. */
 #undef HAVE_MEMPCPY
 
+/* Define to 1 if you have the <minix/config.h> header file. */
+#undef HAVE_MINIX_CONFIG_H
+
 /* Define to 1 if you have the `mmap' function. */
 #undef HAVE_MMAP
 
@@ -298,6 +304,9 @@
 /* Define to 1 if you have the `pwrite64' function. */
 #undef HAVE_PWRITE64
 
+/* Define to 1 if you have the `qsort_r' function. */
+#undef HAVE_QSORT_R
+
 /* Define to 1 if dirent has d_reclen */
 #undef HAVE_RECLEN_DIRENT
 
@@ -343,6 +352,9 @@
 /* Define to 1 if you have the <stdint.h> header file. */
 #undef HAVE_STDINT_H
 
+/* Define to 1 if you have the <stdio.h> header file. */
+#undef HAVE_STDIO_H
+
 /* Define to 1 if you have the <stdlib.h> header file. */
 #undef HAVE_STDLIB_H
 
@@ -478,6 +490,9 @@
 /* Define to 1 if you have the `vprintf' function. */
 #undef HAVE_VPRINTF
 
+/* Define to 1 if you have the <wchar.h> header file. */
+#undef HAVE_WCHAR_H
+
 /* Define to 1 if you have the `__secure_getenv' function. */
 #undef HAVE___SECURE_GETENV
 
@@ -524,7 +539,9 @@
 /* The size of `time_t', as computed by sizeof. */
 #undef SIZEOF_TIME_T
 
-/* Define to 1 if you have the ANSI C header files. */
+/* Define to 1 if all of the C90 standard headers exist (not just the ones
+   required in a freestanding environment). This macro is provided for
+   backward compatibility; new code need not use it. */
 #undef STDC_HEADERS
 
 /* If the compiler supports a TLS storage class define it to that here */
@@ -534,21 +551,87 @@
 #ifndef _ALL_SOURCE
 # undef _ALL_SOURCE
 #endif
+/* Enable general extensions on macOS.  */
+#ifndef _DARWIN_C_SOURCE
+# undef _DARWIN_C_SOURCE
+#endif
+/* Enable general extensions on Solaris.  */
+#ifndef __EXTENSIONS__
+# undef __EXTENSIONS__
+#endif
 /* Enable GNU extensions on systems that have them.  */
 #ifndef _GNU_SOURCE
 # undef _GNU_SOURCE
 #endif
-/* Enable threading extensions on Solaris.  */
+/* Enable X/Open compliant socket functions that do not require linking
+   with -lxnet on HP-UX 11.11.  */
+#ifndef _HPUX_ALT_XOPEN_SOCKET_API
+# undef _HPUX_ALT_XOPEN_SOCKET_API
+#endif
+/* Identify the host operating system as Minix.
+   This macro does not affect the system headers' behavior.
+   A future release of Autoconf may stop defining this macro.  */
+#ifndef _MINIX
+# undef _MINIX
+#endif
+/* Enable general extensions on NetBSD.
+   Enable NetBSD compatibility extensions on Minix.  */
+#ifndef _NETBSD_SOURCE
+# undef _NETBSD_SOURCE
+#endif
+/* Enable OpenBSD compatibility extensions on NetBSD.
+   Oddly enough, this does nothing on OpenBSD.  */
+#ifndef _OPENBSD_SOURCE
+# undef _OPENBSD_SOURCE
+#endif
+/* Define to 1 if needed for POSIX-compatible behavior.  */
+#ifndef _POSIX_SOURCE
+# undef _POSIX_SOURCE
+#endif
+/* Define to 2 if needed for POSIX-compatible behavior.  */
+#ifndef _POSIX_1_SOURCE
+# undef _POSIX_1_SOURCE
+#endif
+/* Enable POSIX-compatible threading on Solaris.  */
 #ifndef _POSIX_PTHREAD_SEMANTICS
 # undef _POSIX_PTHREAD_SEMANTICS
 #endif
+/* Enable extensions specified by ISO/IEC TS 18661-5:2014.  */
+#ifndef __STDC_WANT_IEC_60559_ATTRIBS_EXT__
+# undef __STDC_WANT_IEC_60559_ATTRIBS_EXT__
+#endif
+/* Enable extensions specified by ISO/IEC TS 18661-1:2014.  */
+#ifndef __STDC_WANT_IEC_60559_BFP_EXT__
+# undef __STDC_WANT_IEC_60559_BFP_EXT__
+#endif
+/* Enable extensions specified by ISO/IEC TS 18661-2:2015.  */
+#ifndef __STDC_WANT_IEC_60559_DFP_EXT__
+# undef __STDC_WANT_IEC_60559_DFP_EXT__
+#endif
+/* Enable extensions specified by ISO/IEC TS 18661-4:2015.  */
+#ifndef __STDC_WANT_IEC_60559_FUNCS_EXT__
+# undef __STDC_WANT_IEC_60559_FUNCS_EXT__
+#endif
+/* Enable extensions specified by ISO/IEC TS 18661-3:2015.  */
+#ifndef __STDC_WANT_IEC_60559_TYPES_EXT__
+# undef __STDC_WANT_IEC_60559_TYPES_EXT__
+#endif
+/* Enable extensions specified by ISO/IEC TR 24731-2:2010.  */
+#ifndef __STDC_WANT_LIB_EXT2__
+# undef __STDC_WANT_LIB_EXT2__
+#endif
+/* Enable extensions specified by ISO/IEC 24747:2009.  */
+#ifndef __STDC_WANT_MATH_SPEC_FUNCS__
+# undef __STDC_WANT_MATH_SPEC_FUNCS__
+#endif
 /* Enable extensions on HP NonStop.  */
 #ifndef _TANDEM_SOURCE
 # undef _TANDEM_SOURCE
 #endif
-/* Enable general extensions on Solaris.  */
-#ifndef __EXTENSIONS__
-# undef __EXTENSIONS__
+/* Enable X/Open extensions.  Define to 500 only if necessary
+   to make mbstate_t available.  */
+#ifndef _XOPEN_SOURCE
+# undef _XOPEN_SOURCE
 #endif
 
 
@@ -573,14 +656,4 @@
 /* Define to 1 if Apple Darwin libintl workaround is needed */
 #undef _INTL_REDIRECT_MACROS
 
-/* Define to 1 if on MINIX. */
-#undef _MINIX
-
-/* Define to 2 if the system does not provide POSIX.1 features except with
-   this defined. */
-#undef _POSIX_1_SOURCE
-
-/* Define to 1 if you need to in order for `stat' and other things to work. */
-#undef _POSIX_SOURCE
-
 #include <dirpaths.h>
diff --git a/lib/support/sort_r.h b/lib/support/sort_r.h
index 3292a26ae..ebf78378e 100644
--- a/lib/support/sort_r.h
+++ b/lib/support/sort_r.h
@@ -24,7 +24,11 @@ void sort_r(void *base, size_t nel, size_t width,
 
 #define _SORT_R_INLINE inline
 
-#if (defined __gnu_hurd__ || defined __GNU__ || \
+#if (defined HAVE_GNU_QSORT_R)
+#  define _SORT_R_LINUX
+#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
 #elif (defined __APPLE__ || defined __MACH__ || defined __DARWIN__ || \