util: Add an implementation of qsort_r for non-GNU platforms

Android and MSVC don't have qsort_r() so let's provide a util wrapper
that uses the old qsort and thread-local storage.  We use C++ for this
because thread_local is built into C++11 and we can't rely on C11
everywhere.

Acked-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10989>

meson.build

@@ -1309,7 +1309,8 @@ foreach h : ['xlocale.h', 'linux/futex.h', 'endian.h', 'dlfcn.h', 'execinfo.h',
   endif
 endforeach
 
-foreach f : ['strtof', 'mkostemp', 'timespec_get', 'memfd_create', 'random_r', 'flock', 'strtok_r', 'getrandom']
+foreach f : ['strtof', 'mkostemp', 'timespec_get', 'memfd_create', 'random_r',
+             'flock', 'strtok_r', 'getrandom', 'qsort_r']
   if cc.has_function(f)
     pre_args += '-DHAVE_@0@'.format(f.to_upper())
   endif

src/util/Makefile.sources

@@ -80,6 +80,8 @@ MESA_UTIL_FILES := \
 	os_misc.h \
 	u_process.c \
 	u_process.h \
+	u_qsort.cpp \
+	u_qsort.h \
 	sha1/sha1.c \
 	sha1/sha1.h \
 	ralloc.c \

src/util/meson.build

@@ -79,6 +79,8 @@ files_mesa_util = files(
   'os_socket.h',
   'u_process.c',
   'u_process.h',
+  'u_qsort.cpp',
+  'u_qsort.h',
   'rwlock.h',
   'sha1/sha1.c',
   'sha1/sha1.h',

src/util/u_qsort.cpp

@@ -0,0 +1,44 @@
+/*
+ * Copyright © 2020 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "u_qsort.h"
+#include <thread>
+
+thread_local int (*tl_qsort_r_compar)(const void *, const void *, void *);
+thread_local void *tl_qsort_r_arg;
+
+static int
+qsort_r_compar(const void *a, const void *b)
+{
+   return tl_qsort_r_compar(a, b, tl_qsort_r_arg);
+}
+
+void
+util_tls_qsort_r(void *base, size_t nmemb, size_t size,
+                 int (*compar)(const void *, const void *, void *),
+                 void *arg)
+{
+   tl_qsort_r_compar = compar;
+   tl_qsort_r_arg = arg;
+   return qsort(base, nmemb, size, qsort_r_compar);
+}

src/util/u_qsort.h

@@ -0,0 +1,55 @@
+/*
+ * Copyright © 2020 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef U_QSORT_H
+#define U_QSORT_H
+
+#include <stdlib.h>
+
+#include "detect_os.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void util_tls_qsort_r(void *base, size_t nmemb, size_t size,
+                      int (*compar)(const void *, const void *, void *),
+                      void *arg);
+
+static inline void
+util_qsort_r(void *base, size_t nmemb, size_t size,
+             int (*compar)(const void *, const void *, void *),
+             void *arg)
+{
+#if HAVE_QSORT_R && !(DETECT_OS_APPLE || DETECT_OS_BSD)
+   qsort_r(base, nmemb, size, compar, arg);
+#else
+   util_tls_qsort_r(base, nmemb, size, compar, arg);
+#endif
+}
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* U_QSORT_H */