--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/Wreturn-local-addr-3.c	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,248 @@
+/* PR c/71924 - missing -Wreturn-local-addr returning alloca result
+   { dg-do compile }
+   { dg-options "-O2 -Wall" } */
+
+#define ATTR(...) __attribute__ ((__VA_ARGS__))
+
+typedef __INTPTR_TYPE__ intptr_t;
+
+struct A { int a, b, c; };
+struct B { int a, b, c[]; };
+
+extern int g1[5], g2[5], g3[5], g4[5], g5[5];
+
+void sink (void*, ...);
+
+/* Verify that a pointer difference expression is handled correctly
+   even when converted to a pointer.  */
+
+ATTR (noipa) void*
+return_local_diff_cst (void)
+{
+  int a[5];
+  void *p = (void*)(&a[4] - &a[1]);
+  return p;
+}
+
+ATTR (noipa) void*
+return_local_diff_var (int i, int j)
+{
+  int a[5];
+  void *p = (void*)(&a[j] - &a[i]);
+  return p;
+}
+
+ATTR (noipa) void*
+return_2_locals (int i)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+  void *p = i < 0 ? a : b;
+  return p;         /* { dg-warning "function returns address of local" } */
+}
+
+/* Verify that returning the address of a local converted to intptr_t
+   is not diagnosed (see bug 90737 for a case the front-end gets wrong).  */
+
+ATTR (noipa) intptr_t
+return_int_2_locals (int i)
+{
+  int a[1];
+  int b[2];
+  void *p = i < 0 ? a : b;
+  return (intptr_t)p;
+}
+
+/* Verify that a conditional expression with a pointer first operand
+   is handled correctly.  */
+
+ATTR (noipa) void*
+return_2_locals_ptrcond (void *q)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+  void *p = q ? a : b;
+  return p;         /* { dg-warning "function returns address of local" } */
+}
+
+/* Verify that a preincrement expression with a pointer operand is
+   handled correctly.  */
+
+ATTR (noipa) void*
+return_2_locals_ptrinc (void *q)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+  int *p = q ? a : b;
+  return ++p;       /* { dg-warning "function returns address of local" } */
+}
+
+ATTR (noipa) void*
+return_3_locals (int i)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+  int c[3];         /* { dg-message "declared here" } */
+
+  void *p = i < 0 ? a : 0 < i ? c : b;
+  return p;         /* { dg-warning "function returns address of local" } */
+}
+
+/* Verify that a conditional expression with a pointer first operand
+   is handled correctly.  */
+
+ATTR (noipa) void*
+return_3_locals_ptrcond (void *p, void *q)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+  int c[3];         /* { dg-message "declared here" } */
+
+  void *r = q ? r ? a : b : c;
+  return r;         /* { dg-warning "function returns address of local" } */
+}
+
+ATTR (noipa) void*
+return_5_locals (int i)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+  int c[3];         /* { dg-message "declared here" } */
+  int d[4];         /* { dg-message "declared here" } */
+  int e[5];         /* { dg-message "declared here" } */
+
+  void *p = i < -1 ? a : i < 0 ? b : 1 < i ? e : 0 < i ? d : c;
+  return p;         /* { dg-warning "function returns address of local" } */
+}
+
+ATTR (noipa) void*
+return_1_global_4_locals (int i)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+  int c[3];         /* { dg-message "declared here" } */
+  int d[4];         /* { dg-message "declared here" } */
+
+  void *p = i < -1 ? a : i < 0 ? b : 1 < i ? g1 : 0 < i ? d : c;
+  return p;         /* { dg-warning "function may return address of local" } */
+}
+
+ATTR (noipa) void*
+return_2_globals_3_locals (int i)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+  int c[3];         /* { dg-message "declared here" } */
+
+  void *p = i < -1 ? a : i < 0 ? b : 1 < i ? g1 : 0 < i ? g2 : c;
+  return p;         /* { dg-warning "function may return address of local" } */
+}
+
+ATTR (noipa) void*
+return_3_globals_2_locals (int i)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+
+  void *p = i < -1 ? a : i < 0 ? b : 1 < i ? g1 : 0 < i ? g2 : g3;
+  return p;         /* { dg-warning "function may return address of local" } */
+}
+
+ATTR (noipa) void*
+return_4_globals_1_local (int i)
+{
+  int a[1];         /* { dg-message "declared here" } */
+
+  void *p = i < -1 ? a : i < 0 ? g1 : 1 < i ? g2 : 0 < i ? g4 : g3;
+  return p;         /* { dg-warning "function may return address of local" } */
+}
+
+ATTR (noipa) void*
+return_all_globals (int i)
+{
+  void *p = i < -1 ? g1 : i < 0 ? g2 : 1 < i ? g3 : 0 < i ? g5 : g4;
+  return p;
+}
+
+
+ATTR (noipa) void*
+return_2_alloca_local_cstoff (int n, int i)
+{
+  int *a = __builtin_alloca (n);  /* { dg-message "declared here" } */
+  int *b = __builtin_alloca (n);  /* { dg-message "declared here" } */
+  int *p = i < 0 ? a : b;
+  p += 1;
+  sink (p);
+  return p;         /* { dg-warning "function returns address of local" } */
+}
+
+ATTR (noipa) void*
+return_alloca_local_cstoff (int n, int i)
+{
+  int *a = __builtin_alloca (n);  /* { dg-message "declared here" } */
+  int b[2];                       /* { dg-message "declared here" } */
+  int *p = i < 0 ? a : b;
+  p += 1;
+  sink (p);
+  return p;         /* { dg-warning "function returns address of local" } */
+}
+
+ATTR (noipa) void*
+return_local_alloca_cstoff (int n, int i)
+{
+  int a[2];                       /* { dg-message "declared here" } */
+  int *b = __builtin_alloca (n);  /* { dg-message "declared here" } */
+  int *p = i < 0 ? a : b;
+  p += 1;
+  sink (p);
+  return p;         /* { dg-warning "function returns address of local" } */
+}
+
+ATTR (noipa) void*
+return_2_locals_cstoff (int i)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+  int *p = i < 0 ? a : b;
+  p += 1;
+  sink (p);
+  return p;         /* { dg-warning "function returns address of local" } */
+}
+
+ATTR (noipa) void*
+return_2_globals_3_locals_cstoff (int i)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+  int c[3];         /* { dg-message "declared here" } */
+
+  int *p = i < -1 ? a : i < 0 ? b : 1 < i ? g1 : 0 < i ? g2 : c;
+  p += 1;
+  sink (p);
+  return p;         /* { dg-warning "function may return address of local" } */
+}
+
+ATTR (noipa) void*
+return_3_globals_alloca_local_varoff (int n, int i, int j)
+{
+  int *a = __builtin_alloca (n);  /* { dg-message "declared here" } */
+  int b[2];                       /* { dg-message "declared here" } */
+
+  int *p = i < -1 ? a : i < 0 ? b : 1 < i ? g1 : 0 < i ? g2 : g3;
+  p += j;
+  sink (p);
+  return p;         /* { dg-warning "function may return address of local" } */
+}
+
+ATTR (noipa) void*
+return_3_globals_2_locals_varoff (int i, int j)
+{
+  int a[1];         /* { dg-message "declared here" } */
+  int b[2];         /* { dg-message "declared here" } */
+
+  int *p = i < -1 ? a : i < 0 ? b : 1 < i ? g1 : 0 < i ? g2 : g3;
+  p += j;
+  sink (p);
+  return p;         /* { dg-warning "function may return address of local" } */
+}
+