From e0e1b357435272f8906e8fd70d92c7862e1bc07b Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Tue, 3 Jul 2012 01:03:34 -0400
Subject: [PATCH] re PR c++/53619 ([C++11] wrong capture of "this" in lambda in
 case of multiple inheritance)

	PR c++/53619
	* pt.c (in_template_function): New.
	* cp-tree.h: Declare it.
	* class.c (build_base_path, resolves_to_fixed_type_p): Use it.

From-SVN: r189191
---
 gcc/cp/ChangeLog                              |  5 +++++
 gcc/cp/class.c                                |  6 ++---
 gcc/cp/cp-tree.h                              |  1 +
 gcc/cp/pt.c                                   | 17 ++++++++++++++
 gcc/testsuite/ChangeLog                       |  3 +++
 .../g++.dg/cpp0x/lambda/lambda-this5.C        | 22 +++++++++++++++++++
 6 files changed, 50 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/lambda/lambda-this5.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 580f8cda3abb..2c524230fe43 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,10 @@
 2012-07-02  Jason Merrill  <jason@redhat.com>
 
+	PR c++/53619
+	* pt.c (in_template_function): New.
+	* cp-tree.h: Declare it.
+	* class.c (build_base_path, resolves_to_fixed_type_p): Use it.
+
 	PR c++/53783
 	* pt.c (tsubst_copy_and_build) [LAMBDA_EXPR]: Use tsubst
 	for LAMBDA_EXPR_EXTRA_SCOPE.
diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index e70e6747b55b..0d4a40d4dbec 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -325,8 +325,7 @@ build_base_path (enum tree_code code,
      up properly yet, and the value doesn't matter there either; we're just
      interested in the result of overload resolution.  */
   if (cp_unevaluated_operand != 0
-      || (current_function_decl
-	  && uses_template_parms (current_function_decl)))
+      || in_template_function ())
     {
       expr = build_nop (ptr_target_type, expr);
       if (!want_pointer)
@@ -6523,8 +6522,7 @@ resolves_to_fixed_type_p (tree instance, int* nonnull)
 
   /* processing_template_decl can be false in a template if we're in
      fold_non_dependent_expr, but we still want to suppress this check.  */
-  if (current_function_decl
-      && uses_template_parms (current_function_decl))
+  if (in_template_function ())
     {
       /* In a template we only care about the type of the result.  */
       if (nonnull)
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index a4b7ae3716df..41ca83ca8c9b 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -5330,6 +5330,7 @@ extern tree lookup_template_class		(tree, tree, tree, tree,
 extern tree lookup_template_function		(tree, tree);
 extern int uses_template_parms			(tree);
 extern int uses_template_parms_level		(tree, int);
+extern bool in_template_function		(void);
 extern tree instantiate_class_template		(tree);
 extern tree instantiate_template		(tree, tree, tsubst_flags_t);
 extern int fn_type_unification			(tree, tree, tree,
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index d385ea7ee76c..f618fa557d10 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -8027,6 +8027,23 @@ uses_template_parms (tree t)
   return dependent_p;
 }
 
+/* Returns true iff current_function_decl is an incompletely instantiated
+   template.  Useful instead of processing_template_decl because the latter
+   is set to 0 during fold_non_dependent_expr.  */
+
+bool
+in_template_function (void)
+{
+  tree fn = current_function_decl;
+  bool ret;
+  ++processing_template_decl;
+  ret = (fn && DECL_LANG_SPECIFIC (fn)
+	 && DECL_TEMPLATE_INFO (fn)
+	 && any_dependent_template_arguments_p (DECL_TI_ARGS (fn)));
+  --processing_template_decl;
+  return ret;
+}
+
 /* Returns true if T depends on any template parameter with level LEVEL.  */
 
 int
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index cb62b113a1ae..7ce574a64f55 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2012-07-02  Jason Merrill  <jason@redhat.com>
 
+	PR c++/53619
+	* g++.dg/cpp0x/lambda/lambda-this5.C: New.
+
 	PR c++/53783
 	* g++.dg/cpp0x/lambda/lambda-template7.C: New.
 
diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-this5.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-this5.C
new file mode 100644
index 000000000000..8974641643cb
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-this5.C
@@ -0,0 +1,22 @@
+// PR c++/53619
+// { dg-do run { target c++11 } }
+
+struct C {
+  int x;
+};
+struct B {
+  int q;
+};
+struct A : public B , C  {
+  void foo();
+};
+
+void A::foo() {
+  auto k = [this]() {return (void *)(&x);};
+  if (k() != (void*)&x)
+    __builtin_abort();
+}
+
+int main(int l, char **) {
+  A a; a.foo();
+}