C++ PATCH for c++/65985 (wrong error with constexpr ctor)

[Jason Merrill]

The declaration of __PRETTY_FUNCTION__ was confusing 
build_constexpr_constructor_member_initializers.

Tested x86_64-pc-linux-gnu, applying to trunk.
commit aef1a26de333aab5f602f6eb02cfd1ae751bb84f
Author: Jason Merrill <ja...@redhat.com>
Date:   Wed Feb 17 16:33:50 2016 -0500
    	PR c++/65985
    	* constexpr.c (build_constexpr_constructor_member_initializers):
    	Handle an additional STATEMENT_LIST.

diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index 0eedfca..d3b04b1 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -528,21 +528,32 @@ build_constexpr_constructor_member_initializers (tree type, tree body)
 {
   vec<constructor_elt, va_gc> *vec = NULL;
   bool ok = true;
-  if (TREE_CODE (body) == MUST_NOT_THROW_EXPR
-      || TREE_CODE (body) == EH_SPEC_BLOCK)
-    body = TREE_OPERAND (body, 0);
-  if (TREE_CODE (body) == STATEMENT_LIST)
-    {
-      for (tree_stmt_iterator i = tsi_start (body);
-	   !tsi_end_p (i); tsi_next (&i))
-	{
-	  body = tsi_stmt (i);
-	  if (TREE_CODE (body) == BIND_EXPR)
-	    break;
-	}
+  while (true)
+    switch (TREE_CODE (body))
+      {
+      case MUST_NOT_THROW_EXPR:
+      case EH_SPEC_BLOCK:
+	body = TREE_OPERAND (body, 0);
+	break;
+
+      case STATEMENT_LIST:
+	for (tree_stmt_iterator i = tsi_start (body);
+	     !tsi_end_p (i); tsi_next (&i))
+	  {
+	    body = tsi_stmt (i);
+	    if (TREE_CODE (body) == BIND_EXPR)
+	      break;
+	  }
+	break;
+
+      case BIND_EXPR:
+	body = BIND_EXPR_BODY (body);
+	goto found;
+
+      default:
+	gcc_unreachable ();
     }
-  if (TREE_CODE (body) == BIND_EXPR)
-    body = BIND_EXPR_BODY (body);
+ found:
   if (TREE_CODE (body) == CLEANUP_POINT_EXPR)
     {
       body = TREE_OPERAND (body, 0);
diff --git a/gcc/testsuite/g++.dg/cpp1y/constexpr-assert2.C b/gcc/testsuite/g++.dg/cpp1y/constexpr-assert2.C
new file mode 100644
index 0000000..a329101
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/constexpr-assert2.C
@@ -0,0 +1,31 @@
+// PR c++/65985
+// { dg-do compile { target c++14 } }
+
+#include <cassert>
+
+class Angle
+{
+  int degrees = 0;
+
+  constexpr auto invariant() const noexcept
+  {
+    return 0 <= degrees && degrees < 360;
+  }
+
+public:
+  explicit constexpr Angle(int n) noexcept
+    : degrees{n % 360}
+  {
+    assert(invariant());
+  }
+
+  /* implicit */ constexpr operator auto() const noexcept
+  {
+    return degrees;
+  }
+};
+
+int main()
+{
+  static_assert(Angle{360} == 0, "");
+}