--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/Wstringop-overflow.c	Thu Oct 25 07:37:49 2018 +0900
@@ -0,0 +1,132 @@
+/* PR middle-end/77608 - missing protection on trivially detectable runtime
+   buffer overflow
+   { dg-do compile }
+   { dg-options "-O2 -Wstringop-overflow -ftrack-macro-expansion=0" }  */
+
+#define SIZE_MAX   __SIZE_MAX__
+#define DIFF_MAX   __PTRDIFF_MAX__
+#define DIFF_MIN   (-DIFF_MAX - 1)
+
+typedef __SIZE_TYPE__ size_t;
+
+extern void* memcpy (void*, const void*, size_t);
+extern char* strcpy (char*, const char*);
+extern char* strncpy (char*, const char*, size_t);
+
+void sink (void*);
+
+static size_t unsigned_value (void)
+{
+  extern volatile size_t unsigned_value_source;
+  return unsigned_value_source;
+}
+
+static size_t unsigned_range (size_t min, size_t max)
+{
+  size_t val = unsigned_value ();
+  return val < min || max < val ? min : val;
+}
+
+#define UR(min, max) unsigned_range (min, max)
+
+
+char a7[7];
+
+struct MemArray { char a9[9]; char a1[1]; };
+
+void test_memcpy_array (const void *s)
+{
+#define T(d, s, n) (memcpy ((d), (s), (n)), sink (d))
+
+  T (a7 + UR (0, 1), s, 7);
+  T (a7 + UR (0, 7), s, 7);
+  T (a7 + UR (0, 8), s, 7);
+  T (a7 + UR (0, DIFF_MAX), s, 7);
+  T (a7 + UR (0, SIZE_MAX), s, 7);
+
+  T (a7 + UR (1, 2), s, 7);   /* { dg-warning "writing 7 bytes into a region of size 6" } */
+  T (a7 + UR (2, 3), s, 7);   /* { dg-warning "writing 7 bytes into a region of size 5" } */
+  T (a7 + UR (6, 9), s, 7);   /* { dg-warning "writing 7 bytes into a region of size 1" } */
+  T (a7 + UR (7, 9), s, 7);   /* { dg-warning "writing 7 bytes into a region of size 0" } */
+  T (a7 + UR (8, 9), s, 7);   /* { dg-warning "writing 7 bytes into a region of size 0" } */
+
+  T (a7 + UR (9, 10), s, 7);  /* { dg-warning "writing 7 bytes into a region of size 0" } */
+  T (a7 + UR (DIFF_MAX, DIFF_MAX + (size_t)1), s, 7);  /* { dg-warning "writing 7 bytes into a region of size 0" } */
+  T (a7 + UR (DIFF_MAX, SIZE_MAX), s, 7);  /* { dg-warning "writing 7 bytes into a region of size 0" } */
+
+  /* This is valid.  */
+  char *d = a7 + 7;
+  T (d + UR (-8, -7), s, 7);
+}
+
+/* Verify the absence of warnings for memcpy writing beyond object
+   boundaries. */
+
+void test_memcpy_memarray (struct MemArray *p, const void *s)
+{
+#undef T
+#define T(d, s, n) (memcpy ((d), (s), (n)), sink (d))
+
+  /* The following are valid.  */
+  T (p->a9 + UR (0, 1), s, 9);
+  T (p->a9 + UR (0, 7), s, 9);
+  T (p->a9 + UR (0, 8), s, 9);
+  T (p->a9 + UR (0, DIFF_MAX), s, 9);
+  T (p->a9 + UR (0, SIZE_MAX), s, 9);
+
+  /* The following are invalid.  Unfortunately, there is apparently enough
+     code out there that abuses memcpy to write past the end of one member
+     and into the members that follow so the following are not diagnosed
+     by design.  It sure would be nice not to have to cater to hacks like
+     these...  */
+  T (p->a9 + UR (1, 2), s, 9);
+  T (p->a9 + UR (1, 2), s, 123);
+}
+
+
+void test_strcpy_array (void)
+{
+#undef T
+#define T(d, s) (strcpy ((d), (s)), sink (d))
+
+  T (a7 + UR (0, 1), "012345");
+  T (a7 + UR (0, 7), "012345");
+  T (a7 + UR (0, 8), "012345");
+  T (a7 + UR (0, DIFF_MAX), "012345");
+  T (a7 + UR (0, SIZE_MAX), "012345");
+
+  T (a7 + UR (1, 2), "012345");   /* { dg-warning "writing 7 bytes into a region of size 6" } */
+  T (a7 + UR (2, 3), "012345");   /* { dg-warning "writing 7 bytes into a region of size 5" } */
+  T (a7 + UR (6, 9), "012345");   /* { dg-warning "writing 7 bytes into a region of size 1" } */
+  T (a7 + UR (7, 9), "012345");   /* { dg-warning "writing 7 bytes into a region of size 0" } */
+  T (a7 + UR (8, 9), "012345");   /* { dg-warning "writing 7 bytes into a region of size 0" } */
+
+  T (a7 + UR (9, 10), "012345");  /* { dg-warning "writing 7 bytes into a region of size 0" } */
+  T (a7 + UR (DIFF_MAX, DIFF_MAX + (size_t)1), "012345");  /* { dg-warning "writing 7 bytes into a region of size 0" } */
+  T (a7 + UR (DIFF_MAX, SIZE_MAX), "012345");  /* { dg-warning "writing 7 bytes into a region of size 0" } */
+
+  char *d = a7 + 7;
+
+  T (d + UR (-8, -7), "012345");
+}
+
+void test_strncpy_memarray (struct MemArray *p, const void *s)
+{
+#undef T
+#define T(d, s, n) (strncpy ((d), (s), (n)), sink (d))
+
+  T (p->a9 + UR (0, 1), s, 9);
+  T (p->a9 + UR (0, 7), s, 9);
+  T (p->a9 + UR (0, 8), s, 9);
+  T (p->a9 + UR (0, DIFF_MAX), s, 9);
+  T (p->a9 + UR (0, SIZE_MAX), s, 9);
+
+  T (p->a9 + UR (1, 2), s, 9);    /* { dg-warning "writing 9 bytes into a region of size 8" } */
+  T (p->a9 + UR (2, 3), s, 9);    /* { dg-warning "writing 9 bytes into a region of size 7" } */
+  T (p->a9 + UR (6, 9), s, 9);    /* { dg-warning "writing 9 bytes into a region of size 3" } */
+  T (p->a9 + UR (9, 10), s, 9);   /* { dg-warning "writing 9 bytes into a region of size 0" } */
+  T (p->a9 + UR (10, 11), s, 9);  /* { dg-warning "writing 9 bytes into a region of size 0" } */
+
+  T (p->a9 + UR (DIFF_MAX, DIFF_MAX + (size_t)1), s, 1);  /* { dg-warning "writing 1 byte into a region of size 0" } */
+  T (p->a9 + UR (DIFF_MAX, SIZE_MAX), s, 3);  /* { dg-warning "writing 3 bytes into a region of size 0" } */
+}