util.c: qsort_s in C11

* configure.ac: macro for C11 to use qsort_s.

* util.c (ruby_qsort): fix for C11 qsort_s.  the comparison function
  for MSVCRT qsort_s is compatible with BSD qsort_r, but not with C11
  qsort_s, in spite of its name.
  note that mingw defines __STDC_VERSION__ but uses qsort_s in MSVCRT,
  so the MSVCRT block needs to preced the C11 block.
  [ruby-core:88899] [Bug #15091]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64661 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

configure.ac

@@ -1869,7 +1869,7 @@ AC_CHECK_FUNCS(utimes)
 AC_CHECK_FUNCS(wait4)
 AC_CHECK_FUNCS(waitpid)
 
-AS_IF([test "$ac_cv_func_memset_s" = yes],
+AS_CASE(["$ac_cv_func_memset_s:$ac_cvs_func_qsort_s"], [*yes*],
     [RUBY_DEFINE_IF([!defined __STDC_WANT_LIB_EXT1__], [__STDC_WANT_LIB_EXT1__], 1)])
 
 AS_IF([test "$ac_cv_func_getcwd" = yes], [

util.c

@@ -195,14 +195,32 @@ ruby_strtoul(const char *str, char **endptr, int base)
 #   define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
 #endif
 
-#if !defined HAVE_BSD_QSORT_R && defined HAVE_QSORT_S
+typedef int (cmpfunc_t)(const void*, const void*, void*);
+
+#if defined HAVE_QSORT_S
+# if defined __MSVCRT__
 # define qsort_r(base, nel, size, arg, cmp) qsort_s(base, nel, size, cmp, arg)
 # define cmp_bsd_qsort cmp_ms_qsort
 # define HAVE_BSD_QSORT_R 1
-#endif
-#if defined HAVE_BSD_QSORT_R
-typedef int (cmpfunc_t)(const void*, const void*, void*);
+# elif defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L
+/* C11 qsort_s has the same arguments as ours */
+void
+ruby_qsort(void* base, const size_t nel, const size_t size, cmpfunc_t *cmp, void *d)
+{
+    if (!nel || !size) return;  /* nothing to sort */
 
+    /* get rid of runtime-constraints handler for MT-safeness */
+    if (!base || !cmp) return;
+    if (nel > RSIZE_MAX || size > RSIZE_MAX) return;
+
+    qsort_s(base, nel, size, cmp, d);
+}
+# else
+#   error Unknown version qsort_s
+# endif
+#endif
+
+#if defined HAVE_BSD_QSORT_R
 struct bsd_qsort_r_args {
     cmpfunc_t *cmp;
     void *arg;
@@ -339,7 +357,6 @@ typedef struct { char *LL, *RR; } stack_node; /* Stack structure for L,l,R,r */
                        ((*cmp)((b),(c),d)<0 ? (b) : ((*cmp)((a),(c),d)<0 ? (c) : (a))) : \
                        ((*cmp)((b),(c),d)>0 ? (b) : ((*cmp)((a),(c),d)<0 ? (a) : (c))))
 
-typedef int (cmpfunc_t)(const void*, const void*, void*);
 void
 ruby_qsort(void* base, const size_t nel, const size_t size, cmpfunc_t *cmp, void *d)
 {