--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/Wstringop-overflow-23.c	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,176 @@
+/* PR middle-end/83859 - attribute to establish relation between parameters
+   for buffer and its size
+   Test to verify that with optimization enabled, -Wstringop-overflow
+   warnings are issued for calls to user-defined functions with attribute
+   access and with non-constant out-of-bounds arguments.
+   { dg-do compile }
+   { dg-options "-O2 -Wall" } */
+
+#include "range.h"
+
+#define INT_MAX   __INT_MAX__
+#define INT_MIN   (-INT_MAX - 1)
+
+#define RDONLY(...)  __attribute__ ((access (read_only, __VA_ARGS__)))
+#define WRONLY(...)  __attribute__ ((access (write_only, __VA_ARGS__)))
+#define RDWR(...)  __attribute__ ((access (read_write, __VA_ARGS__)))
+
+typedef __INT32_TYPE__ int32_t;
+
+/* Exercise null pointer detection.  */
+
+RDONLY (2, 1) void
+rd2_1 (int, const void*);       // { dg-message "in a call to function 'rd2_1' declared with attribute 'read_only \\\(2, 1\\\)" }
+
+void test_rd2_1 (void)
+{
+  {
+    void *null = 0;
+    void *p = &null;
+
+    rd2_1 (0, null);
+    rd2_1 (1, p);
+  }
+
+  {
+    void *null = 0;
+    rd2_1 (1, null);            // { dg-warning "argument 2 is null but the corresponding size argument 1 value is 1" }
+  }
+
+  {
+    void *null = 0;
+    rd2_1 (SR (1, 2), null);    // { dg-warning "argument 2 is null but the corresponding size argument 1 range is \\\[1, 2]" }
+  }
+}
+
+WRONLY (3, 1) void
+wr3_1 (int, int, void*);        // { dg-message "in a call to function 'wr3_1' declared with attribute 'write_only \\\(3, 1\\\)" }
+
+void test_wr3_1 (void)
+{
+  {
+    void *null = 0;
+    void *p = &null;
+
+    wr3_1 (SR (0, 1), 0, null);
+    wr3_1 (SR (1, 1), 0, p);
+  }
+
+  void *null = 0;
+
+  wr3_1 (SR (1, 2), 1, null);   // { dg-warning "argument 3 is null but the corresponding size argument 1 range is \\\[1, 2]" }
+}
+
+
+WRONLY (2, 1) void
+wr2_1 (int, void*);
+
+void test_wrd2_1 (int n)
+{
+  wr2_1 (0, 0);
+  wr2_1 (SR (-1, 1), 0);
+  wr2_1 (SR (0, 1), 0);
+  wr2_1 (SR (1, 2), 0);         // { dg-warning "argument 2 is null but the corresponding size argument 1 range is \\\[1, 2]" }
+
+  /* This should probably be diagnosed but to avoid false positives
+     caused by jump threading and such it would have to be done
+     earlier than it is now.  */
+  wr2_1 (n, 0);                 // { dg-warning "argument 2 is null" "unimplemented" { xfail *-*-* } }
+}
+
+
+/* Exercise pointer to an incomplete type other than void.  */
+
+struct Incomplete;
+extern struct Incomplete inc;
+
+extern char ax[];
+
+WRONLY (1, 2) void
+wr1_2_inc (struct Incomplete*, unsigned);
+
+void test_wr1_2_inc (struct Incomplete *pinc, unsigned n)
+{
+  wr1_2_inc (0, 0);
+  wr1_2_inc (0, 1);         // { dg-warning "argument 1 is null but the corresponding size argument 2 value is 1" }
+
+  wr1_2_inc (pinc, 1);
+  wr1_2_inc (&inc, 1);
+
+  wr1_2_inc (pinc, 123);
+  wr1_2_inc (&inc, 456);
+
+  char a3[3];
+  pinc = (struct Incomplete*)a3;
+  wr1_2_inc (pinc, SR (3, 4));
+  wr1_2_inc (pinc, SR (4, 5));
+  // { dg-warning "'wr1_2_inc' writing between 4 and 5 bytes into a region of size 3" "small buffer cast to incomplete" { target *-*-* } .-1 }
+
+  pinc = (struct Incomplete*)ax;
+  wr1_2_inc (pinc, SR (123, 456));
+
+  char vla[n];
+  pinc = (struct Incomplete*)vla;
+  wr1_2_inc (pinc, SR (345, 456));
+}
+
+
+RDONLY (1, 3) WRONLY (2, 4) void
+rd1_3_wr2_4 (const void*, void*, int, int);
+
+void test_rd1_3_wr2_4 (const void *s, void *d, int n1, int n2)
+{
+  rd1_3_wr2_4 (s, d, 1, 2);
+  rd1_3_wr2_4 (s, d, 123, 456);
+  rd1_3_wr2_4 (s, d, INT_MAX, INT_MAX);
+  rd1_3_wr2_4 (s, d, -1, 2);    // { dg-warning "argument 3 value -1 is negative" }
+
+  const int ir_min_m1 = SR (INT_MIN, -1);
+  rd1_3_wr2_4 (s, d, ir_min_m1, 2);   // { dg-warning "argument 3 range \\\[-\[0-9\]+, -1] is negative" }
+
+  rd1_3_wr2_4 (s, d, SR (-1, 0), 2);
+  rd1_3_wr2_4 (s, d, SR (INT_MIN, INT_MAX), 2);
+
+  rd1_3_wr2_4 (s, d, n1, n2);
+
+
+  const char s11[11] = "0123456789";
+
+  rd1_3_wr2_4 (s11, d, 11, n2);
+  rd1_3_wr2_4 (s11, d, 12, n2);   // { dg-warning "'rd1_3_wr2_4' reading 12 bytes from a region of size 11" }
+
+  rd1_3_wr2_4 (s11, d, SR (0, 11), n2);
+  rd1_3_wr2_4 (s11, d, SR (0, 12), n2);
+  rd1_3_wr2_4 (s11, d, SR (11, 12), n2);
+  rd1_3_wr2_4 (s11, d, SR (11, INT_MAX), n2);
+  rd1_3_wr2_4 (s11, d, SR (12, 13), n2);  // { dg-warning "'rd1_3_wr2_4' reading between 12 and 13 bytes from a region of size 11" }
+
+  char d4[4];
+  rd1_3_wr2_4 (s, d4, n1, 4);
+  rd1_3_wr2_4 (s, d4, n1, 5);     // { dg-warning "'rd1_3_wr2_4' writing 5 bytes into a region of size 4" }
+
+  rd1_3_wr2_4 (s11, d4, SR (12, 13), SR (5, 6));
+  // { dg-warning "'rd1_3_wr2_4' reading between 12 and 13 bytes from a region of size 11" "read" { target *-*-* } .-1 }
+  // { dg-warning "'rd1_3_wr2_4' writing between 5 and 6 bytes into a region of size 4" "read" { target *-*-* } .-2 }
+}
+
+
+/* Verify that function pointers are handled.  */
+
+RDONLY (1) void (*pfrd1)(const void*, const void*);
+
+void test_pfrd1 (void)
+{
+  pfrd1 ("" + SR (0, 9), "" + SR (1, 9));
+  pfrd1 ("" + SR (1, 2), "");   // { dg-warning "reading 1 byte from a region of size 0" }
+}
+
+
+WRONLY (4, 3) void (*pfwr4_3)(int, const char*, int, int32_t*);
+
+void test_pfwr4_3 (void)
+{
+  int32_t i;
+  pfwr4_3 (3, "", 0, &i + SR (0, 9));
+  pfwr4_3 (5, "", 1, &i + SR (1, 2));   // { dg-warning "writing 4 bytes into a region of size 0" }
+}