From: Jason Merrill <jason@redhat.com>
Date: Tue, 30 Aug 2011 15:28:30 +0000 (-0400)
Subject: re PR c++/50234 (internal compiler error: in cxx_eval_component_reference, at cp... 
X-Git-Tag: releases/gcc-4.7.0~4097
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d05da2b9d529b199ff3589353e91ec4440f5ab1f;p=thirdparty%2Fgcc.git

re PR c++/50234 (internal compiler error: in cxx_eval_component_reference, at cp/semantics.c:6527)

	PR c++/50234
	* semantics.c (cxx_eval_component_reference): Handle
	value-initialization for omitted initializers.

From-SVN: r178325
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 315078aad33e..9abac29a151e 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2011-08-30  Jason Merrill  <jason@redhat.com>
+
+	PR c++/50234
+	* semantics.c (cxx_eval_component_reference): Handle
+	value-initialization for omitted initializers.
+
 2011-08-29  Jason Merrill  <jason@redhat.com>
 
 	PR c++/50224
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 07f53b5cd127..1ad991fab4e0 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -6518,7 +6518,8 @@ cxx_eval_component_reference (const constexpr_call *call, tree t,
       if (field == part)
         return value;
     }
-  if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE)
+  if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE
+      && CONSTRUCTOR_NELTS (whole) > 0)
     {
       /* DR 1188 says we don't have to deal with this.  */
       if (!allow_non_constant)
@@ -6527,8 +6528,12 @@ cxx_eval_component_reference (const constexpr_call *call, tree t,
       *non_constant_p = true;
       return t;
     }
-  gcc_unreachable();
-  return error_mark_node;
+
+  /* If there's no explicit init for this field, it's value-initialized.  */
+  value = build_value_init (TREE_TYPE (t), tf_warning_or_error);
+  return cxx_eval_constant_expression (call, value,
+				       allow_non_constant, addr,
+				       non_constant_p);
 }
 
 /* Subroutine of cxx_eval_constant_expression.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2449a63ac63b..237deac888c2 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-08-30  Jason Merrill  <jason@redhat.com>
+
+	PR c++/50234
+	* g++.dg/cpp0x/constexpr-value3.C: New.
+
 2011-08-30  Richard Guenther  <rguenther@suse.de>
 
 	PR middle-end/48571
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-value3.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-value3.C
new file mode 100644
index 000000000000..38d89936ec4d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-value3.C
@@ -0,0 +1,10 @@
+// PR c++/50234
+// { dg-options -std=c++0x }
+
+#define SA(X) static_assert((X),#X)
+
+struct A { int i; };
+
+constexpr int f(A a) { return a.i; }
+
+SA(f({}) == 0);