[committed] asan, v2: Fix ICE during instrumentation of returns_twice calls [PR112709]

[Jakub Jelinek]

On Tue, Mar 12, 2024 at 02:46:07PM +0100, Richard Biener wrote:
> OK.

Thanks.  Here is the actually committed version which uses
gsi_safe_insert_before instead.

Bootstrapped/regtested on x86_64-linux and i686-linux, committed to
trunk.

2024-03-13  Jakub Jelinek  <ja...@redhat.com>

        PR sanitizer/112709
        * asan.cc (maybe_create_ssa_name, maybe_cast_to_ptrmode,
        build_check_stmt, maybe_instrument_call, asan_expand_mark_ifn): Use
        gsi_safe_insert_before instead of gsi_insert_before.

        * gcc.dg/asan/pr112709-2.c: New test.

--- gcc/asan.cc.jj      2024-03-11 13:49:58.931045179 +0100
+++ gcc/asan.cc 2024-03-11 18:38:29.047330489 +0100
@@ -2574,7 +2589,7 @@ maybe_create_ssa_name (location_t loc, t
   gimple *g = gimple_build_assign (make_ssa_name (TREE_TYPE (base)), base);
   gimple_set_location (g, loc);
   if (before_p)
-    gsi_insert_before (iter, g, GSI_SAME_STMT);
+    gsi_safe_insert_before (iter, g);
   else
     gsi_insert_after (iter, g, GSI_NEW_STMT);
   return gimple_assign_lhs (g);
@@ -2593,7 +2608,7 @@ maybe_cast_to_ptrmode (location_t loc, t
                                  NOP_EXPR, len);
   gimple_set_location (g, loc);
   if (before_p)
-    gsi_insert_before (iter, g, GSI_SAME_STMT);
+    gsi_safe_insert_before (iter, g);
   else
     gsi_insert_after (iter, g, GSI_NEW_STMT);
   return gimple_assign_lhs (g);
@@ -2684,7 +2699,7 @@ build_check_stmt (location_t loc, tree b
                                                 align / BITS_PER_UNIT));
   gimple_set_location (g, loc);
   if (before_p)
-    gsi_insert_before (&gsi, g, GSI_SAME_STMT);
+    gsi_safe_insert_before (&gsi, g);
   else
     {
       gsi_insert_after (&gsi, g, GSI_NEW_STMT);
@@ -3025,7 +3040,7 @@ maybe_instrument_call (gimple_stmt_itera
          tree decl = builtin_decl_implicit (BUILT_IN_ASAN_HANDLE_NO_RETURN);
          gimple *g = gimple_build_call (decl, 0);
          gimple_set_location (g, gimple_location (stmt));
-         gsi_insert_before (iter, g, GSI_SAME_STMT);
+         gsi_safe_insert_before (iter, g);
        }
     }
 
@@ -3852,7 +3867,7 @@ asan_expand_mark_ifn (gimple_stmt_iterat
       g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
                               NOP_EXPR, len);
       gimple_set_location (g, loc);
-      gsi_insert_before (iter, g, GSI_SAME_STMT);
+      gsi_safe_insert_before (iter, g);
       tree sz_arg = gimple_assign_lhs (g);
 
       tree fun
--- gcc/testsuite/gcc.dg/asan/pr112709-2.c.jj   2024-03-11 18:30:59.813488200 
+0100
+++ gcc/testsuite/gcc.dg/asan/pr112709-2.c      2024-03-11 18:31:06.506396462 
+0100
@@ -0,0 +1,50 @@
+/* PR sanitizer/112709 */
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=address -O2" } */
+
+struct S { char c[1024]; } *p;
+int foo (int);
+
+__attribute__((returns_twice, noipa)) int
+bar (struct S x)
+{
+  (void) x.c[0];
+  return 0;
+}
+
+void
+baz (int *y)
+{
+  foo (1);
+  *y = bar (*p);
+}
+
+void
+qux (int x, int *y)
+{
+  if (x == 25)
+    x = foo (2);
+  else if (x == 42)
+    x = foo (foo (3));
+  *y = bar (*p);
+}
+
+void
+corge (int x, int *y)
+{
+  void *q[] = { &&l1, &&l2, &&l3, &&l3 };
+  if (x == 25)
+    {
+    l1:
+      x = foo (2);
+    }
+  else if (x == 42)
+    {
+    l2:
+      x = foo (foo (3));
+    }
+l3:
+  *y = bar (*p);
+  if (x < 4)
+    goto *q[x & 3];
+}


        Jakub