From d79ca2074fdb83ace6f79ccf3530285d8b15be8c Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Fri, 25 Jan 2008 19:41:49 -0500
Subject: [PATCH] re PR c++/27177 (ICE in build_simple_base_path, at
 cp/class.c:474)

        PR c++/27177
        * class.c (build_base_path): Don't mess with virtual access if
        skip_evaluation.
        * call.c (standard_conversion): Don't check whether source type
        is complete.

From-SVN: r131855
---
 gcc/cp/ChangeLog                  |  6 ++++++
 gcc/cp/call.c                     | 14 +-------------
 gcc/cp/class.c                    |  3 ++-
 gcc/testsuite/g++.dg/expr/cast9.C | 12 ++++++++++++
 4 files changed, 21 insertions(+), 14 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/expr/cast9.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index e8d8adf2049..1f05c682699 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -8,6 +8,12 @@
 
 2008-01-25  Jason Merrill  <jason@redhat.com>
 
+	PR c++/27177
+	* class.c (build_base_path): Don't mess with virtual access if
+	skip_evaluation.
+	* call.c (standard_conversion): Don't check whether source type
+	is complete.
+
 	* decl2.c (is_late_template_attribute): Don't defer attribute
 	visibility just because the type is dependent.
 
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 3cd80b40dac..c4e4c793982 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -745,19 +745,7 @@ standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
 		  that necessitates this conversion is ill-formed.
 		  Therefore, we use DERIVED_FROM_P, and do not check
 		  access or uniqueness.  */
-	       && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from))
-	       /* If FROM is not yet complete, then we must be parsing
-		  the body of a class.  We know what's derived from
-		  what, but we can't actually perform a
-		  derived-to-base conversion.  For example, in:
-
-		     struct D : public B { 
-                       static const int i = sizeof((B*)(D*)0);
-                     };
-
-                  the D*-to-B* conversion is a reinterpret_cast, not a
-		  static_cast.  */
-	       && COMPLETE_TYPE_P (TREE_TYPE (from)))
+	       && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from)))
 	{
 	  from =
 	    cp_build_qualified_type (TREE_TYPE (to),
diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 65e7144bfd7..6b76bf7477f 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -291,7 +291,8 @@ build_base_path (enum tree_code code,
   target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo);
 
   /* Do we need to look in the vtable for the real offset?  */
-  virtual_access = (v_binfo && fixed_type_p <= 0);
+  /* Don't bother inside sizeof; the source type might not be complete.  */
+  virtual_access = (v_binfo && fixed_type_p <= 0) && !skip_evaluation;
 
   /* Do we need to check for a null pointer?  */
   if (want_pointer && !nonnull)
diff --git a/gcc/testsuite/g++.dg/expr/cast9.C b/gcc/testsuite/g++.dg/expr/cast9.C
new file mode 100644
index 00000000000..150183a3898
--- /dev/null
+++ b/gcc/testsuite/g++.dg/expr/cast9.C
@@ -0,0 +1,12 @@
+// PR c++/27177
+
+struct Z {};
+struct A : Z {};
+
+Z* implicitToZ (Z*);
+
+struct B : A
+{
+  static const int i = sizeof(implicitToZ((B*)0));
+};
+