--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/attr-alloc_size-7.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,73 @@
+/* PR c/78284 - warn on malloc with very large arguments
+   Test exercising the ability of the built-in allocation functions to
+   detect and diagnose calls that attemnpt to allocate objects in excess
+   of the maximum specified by -Walloc-size-larger-than=maximum.  */
+/* { dg-do compile } */
+/* { dg-require-effective-target alloca } */
+/* { dg-options "-O2 -Wall -Walloc-size-larger-than=12345" } */
+
+#define SIZE_MAX   __SIZE_MAX__
+#define MAXOBJSZ   12345
+
+typedef __SIZE_TYPE__ size_t;
+
+void sink (void*);
+
+size_t maxobjsize (void)
+{
+  return MAXOBJSZ;
+}
+
+
+void test_var (void *p)
+{
+  size_t max = maxobjsize ();
+
+  sink (__builtin_aligned_alloc (1, max));
+  sink (__builtin_aligned_alloc (1, max + 1));   /* { dg-warning "argument 2 value .12346\[lu\]*. exceeds maximum object size 12345" } */
+
+  sink (__builtin_alloca (max));
+  sink (__builtin_alloca (max + 2));   /* { dg-warning "argument 1 value .12347\[lu\]*. exceeds maximum object size 12345" } */
+
+  sink (__builtin_calloc (1, max));
+  sink (__builtin_calloc (max, 1));
+
+  sink (__builtin_calloc (max / 2, 3));   /* { dg-warning "product .6172\[lu\]* \\* 3\[lu\]*. of arguments 1 and 2 exceeds maximum object size 12345" } */
+  sink (__builtin_calloc (4, max / 3));   /* { dg-warning "product .4\[lu\]* \\* 4115\[lu\]*. of arguments 1 and 2 exceeds maximum object size 12345" } */
+
+  sink (__builtin_malloc (max));
+  sink (__builtin_malloc (max + 3));   /* { dg-warning "argument 1 value .12348\[lu\]*. exceeds maximum object size 12345" } */
+
+  sink (__builtin_realloc (p, max));
+  sink (__builtin_realloc (p, max + 4));  /* { dg-warning "argument 2 value .12349\[lu\]*. exceeds maximum object size 12345" } */
+}
+
+
+void test_range (void *p, size_t range)
+{
+  /* Make sure the variable is at least as large as the maximum object
+     size but also make sure that it's guaranteed not to be too big to
+     increment (and wrap around).  */
+  size_t max = maxobjsize ();
+
+  if (range < max || 2 * max <= range)
+    range = maxobjsize ();
+
+  sink (__builtin_aligned_alloc (1, range));
+  sink (__builtin_aligned_alloc (1, range + 1));   /* { dg-warning "argument 2 range \\\[12346\[lu\]*, \[0-9\]+\[lu\]*\\\] exceeds maximum object size 12345" } */
+
+  sink (__builtin_alloca (range));
+  sink (__builtin_alloca (range + 2));   /* { dg-warning "argument 1 range \\\[12347\[lu\]*, \[0-9\]+\[lu\]*\\\] exceeds maximum object size 12345" } */
+
+  sink (__builtin_calloc (range, 1));
+  sink (__builtin_calloc (1, range));
+
+  sink (__builtin_calloc (range / 2, 3));   /* { dg-warning "product .6172\[lu\]* \\* 3\[lu\]*. of arguments 1 and 2 exceeds maximum object size 12345" } */
+  sink (__builtin_calloc (4, range / 3));   /* { dg-warning "product .4\[lu\]* \\* 4115\[lu\]*. of arguments 1 and 2 exceeds maximum object size 12345" } */
+
+  sink (__builtin_malloc (range));
+  sink (__builtin_malloc (range + 3));   /* { dg-warning "argument 1 range \\\[12348\[lu\]*, 24692\[lu\]*\\\] exceeds maximum object size 12345" } */
+
+  sink (__builtin_realloc (p, range));
+  sink (__builtin_realloc (p, range + 4));  /* { dg-warning "argument 2 range \\\[12349\[lu\]*, 24693\[lu\]*\\\] exceeds maximum object size 12345" } */
+}