re PR middle-end/90194 (ICE in expand_debug_expr, at cfgexpand.c:5244)

2019-04-25  Richard Biener  <rguenther@suse.de>

	PR middle-end/90194
	* match.pd: Add pattern to simplify view-conversion of an
	empty constructor.

	* g++.dg/torture/pr90194.C: New testcase.

From-SVN: r270569

gcc/ChangeLog

@@ -1,3 +1,9 @@
+2019-04-25  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/90194
+	* match.pd: Add pattern to simplify view-conversion of an
+	empty constructor.
+
 2019-04-24  Clement Chigot  <clement.chigot@atos.net>
 
 	* config/rs6000/aix71.h (SUBTARGET_OVERRIDE_OPTIONS): Disable

gcc/match.pd

@@ -2596,6 +2596,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 	       && TYPE_UNSIGNED (TREE_TYPE (@1)))))
    (view_convert @1)))
 
+/* Simplify a view-converted empty constructor.  */
+(simplify
+  (view_convert CONSTRUCTOR@0)
+  (if (TREE_CODE (@0) != SSA_NAME
+       && CONSTRUCTOR_NELTS (@0) == 0)
+   { build_zero_cst (type); }))
+
 /* Re-association barriers around constants and other re-association
    barriers can be removed.  */
 (simplify

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2019-04-25  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/90194
+	* g++.dg/torture/pr90194.C: New testcase.
+
 2019-04-24  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/90236

gcc/testsuite/g++.dg/torture/pr90194.C

@@ -0,0 +1,18 @@
+// { dg-do compile }
+// { dg-additional-options "-g" }
+
+struct cb {
+    int yr;
+};
+
+void *
+operator new (__SIZE_TYPE__, void *nq)
+{
+  return nq;
+}
+
+void
+af (int xn)
+{
+  new (&xn) cb { };
+}