middle-end/112741 - ICE with gimple FE and later regimplification

The GIMPLE frontend, when bypassing gimplification, doesn't set
DECL_SEEN_IN_BIND_EXPR_P given there are no such things in GIMPLE.
But it probably should set the flag anyway to avoid later ICEs
when regimplifying.

	PR middle-end/112741
gcc/c/
	* gimple-parser.cc (c_parser_parse_gimple_body): Also
	set DECL_SEEN_IN_BIND_EXPR_Pfor locals.

gcc/testsuite/
	* gcc.dg/ubsan/pr112741.c: New testcase.

2 files changed, 28 insertions, 1 deletions

diff --git a/gcc/c/gimple-parser.cc b/gcc/c/gimple-parser.cc
index f43c039..72bff1c 100644
--- a/gcc/c/gimple-parser.cc
+++ b/gcc/c/gimple-parser.cc
@@ -280,7 +280,13 @@ c_parser_parse_gimple_body (c_parser *cparser, char *gimple_pass,
       for (tree var = BIND_EXPR_VARS (stmt); var; var = DECL_CHAIN (var))
 	if (VAR_P (var)
 	    && !DECL_EXTERNAL (var))
-	  add_local_decl (cfun, var);
+	  {
+	    add_local_decl (cfun, var);
+	    /* When the middle-end re-gimplifies any expression we might
+	       run into the assertion that we've seen the decl in a BIND.  */
+	    if (!TREE_STATIC (var))
+	      DECL_SEEN_IN_BIND_EXPR_P (var) = 1;
+	  }
       /* We have a CFG.  Build the edges.  */
       for (unsigned i = 0; i < parser.edges.length (); ++i)
 	{
diff --git a/gcc/testsuite/gcc.dg/ubsan/pr112741.c b/gcc/testsuite/gcc.dg/ubsan/pr112741.c
new file mode 100644
index 0000000..13994f6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ubsan/pr112741.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-fgimple -fsanitize=undefined" } */
+
+int __GIMPLE(ssa) foo(int j)
+{
+  int c[1][10][1];
+  int _1;
+
+__BB(2):
+  c[0][1][0] = 1;
+  c[0][1] = _Literal (int[1]) {};
+  _1 = c[0][j_2(D)][0];
+  return _1;
+}
+
+int main()
+{
+  if (foo (1) != 0)
+    __builtin_abort ();
+  return 0;
+}