1 files changed, 141 insertions, 0 deletions
diff --git a/tests/test-stddef-h.c b/tests/test-stddef-h.c
new file mode 100644
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--- /dev/null
+++ b/tests/test-stddef-h.c
@@ -0,0 +1,141 @@
+/* Test of <stddef.h> substitute.
+   Copyright (C) 2009-2025 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Eric Blake <ebb9@byu.net>, 2009.  */
+
+#include <config.h>
+
+#include <stddef.h>
+
+/* Check that appropriate types are defined.  */
+wchar_t a = 'c';
+ptrdiff_t b = 1;
+size_t c = 2;
+#if !defined __cplusplus || __cplusplus >= 201103
+max_align_t mat;
+#endif
+
+#if !(defined __cplusplus && defined _MSC_VER)
+/* Check that NULL can be passed through varargs as a pointer type,
+   per POSIX 2008.  */
+static_assert (sizeof NULL == sizeof (void *));
+#endif
+
+/* Check that offsetof produces integer constants with correct type.  */
+struct d
+{
+  char e;
+  char f;
+};
+/* Solaris 10 has a bug where offsetof is under-parenthesized, and
+   cannot be used as an arbitrary expression.  However, since it is
+   unlikely to bite real code, we ignore that short-coming.  */
+/* static_assert (sizeof offsetof (struct d, e) == sizeof (size_t)); */
+static_assert (sizeof (offsetof (struct d, e)) == sizeof (size_t));
+static_assert (offsetof (struct d, f) == 1);
+
+#if !defined __cplusplus || __cplusplus >= 201103
+/* Check max_align_t's alignment.  */
+static_assert (alignof (double) <= alignof (max_align_t));
+static_assert (alignof (int) <= alignof (max_align_t));
+static_assert (alignof (long double) <= alignof (max_align_t));
+static_assert (alignof (long int) <= alignof (max_align_t));
+static_assert (alignof (ptrdiff_t) <= alignof (max_align_t));
+static_assert (alignof (size_t) <= alignof (max_align_t));
+static_assert (alignof (wchar_t) <= alignof (max_align_t));
+static_assert (alignof (struct d) <= alignof (max_align_t));
+# if defined __GNUC__ || defined __clang__ || defined __IBM__ALIGNOF__
+static_assert (__alignof__ (double) <= __alignof__ (max_align_t));
+static_assert (__alignof__ (int) <= __alignof__ (max_align_t));
+static_assert (__alignof__ (long double) <= __alignof__ (max_align_t));
+static_assert (__alignof__ (long int) <= __alignof__ (max_align_t));
+static_assert (__alignof__ (ptrdiff_t) <= __alignof__ (max_align_t));
+static_assert (__alignof__ (size_t) <= __alignof__ (max_align_t));
+static_assert (__alignof__ (wchar_t) <= __alignof__ (max_align_t));
+static_assert (__alignof__ (struct d) <= __alignof__ (max_align_t));
+# endif
+#endif
+
+
+#ifndef __cplusplus
+
+/* Test 'unreachable'.  */
+
+int test_unreachable_optimization (int x);
+_Noreturn void test_unreachable_noreturn (void);
+
+int
+test_unreachable_optimization (int x)
+{
+  /* Check that the compiler uses 'unreachable' for optimization.
+     This function, when compiled with optimization, should have code
+     equivalent to
+       return x + 3;
+     Use 'objdump --disassemble test-stddef.o' to verify this.  */
+  if (x < 4)
+    unreachable ();
+  return (x > 1 ? x + 3 : 2 * x + 10);
+}
+
+_Noreturn void
+test_unreachable_noreturn (void)
+{
+  /* Check that the compiler's data-flow analysis recognizes 'unreachable ()'.
+     This function should not elicit a warning.  */
+  unreachable ();
+}
+
+#endif
+
+
+/* Test 'gl_unreachable'.  */
+
+int test_gl_unreachable_optimization (int x);
+_Noreturn void test_gl_unreachable_noreturn (void);
+
+int
+test_gl_unreachable_optimization (int x)
+{
+  /* Check that the compiler uses 'gl_unreachable' for optimization.
+     This function, when compiled with optimization, should have code
+     equivalent to
+       return x + 3;
+     Use 'objdump --disassemble test-stddef.o' to verify this.  */
+  if (x < 4)
+    gl_unreachable ();
+  return (x > 1 ? x + 3 : 2 * x + 10);
+}
+
+_Noreturn void
+test_gl_unreachable_noreturn (void)
+{
+  /* Check that the compiler's data-flow analysis recognizes
+     'gl_unreachable ()'.  This function should not elicit a warning.  */
+  gl_unreachable ();
+}
+
+
+#include <limits.h> /* INT_MAX */
+
+/* offsetof promotes to an unsigned integer if and only if sizes do
+   not fit in int.  */
+static_assert ((offsetof (struct d, e) < -1) == (INT_MAX < (size_t) -1));
+
+int
+main (void)
+{
+  return 0;
+}