C++ PATCH for c++/48531 (SFINAE and array of unknown bound)

[Jason Merrill]

Here's the one where we just need to check complain before giving an error.

Tested x86_64-pc-linux-gnu, applying to trunk.

commit a9fa1134b357ad03ac5279c926d67af75728062d
Author: Jason Merrill <ja...@redhat.com>
Date:   Wed Apr 13 18:17:17 2011 -0400

        PR c++/48531
        * init.c (build_value_init_noctor): Check complain consistently.

diff --git a/gcc/cp/init.c b/gcc/cp/init.c
index 32afa03..fad7f0c 100644
--- a/gcc/cp/init.c
+++ b/gcc/cp/init.c
@@ -422,7 +422,9 @@ build_value_init_noctor (tree type, tsubst_flags_t complain)
         as we don't know the size of the array yet.  */
       if (max_index == error_mark_node)
        {
-         error ("cannot value-initialize array of unknown bound %qT", type);
+         if (complain & tf_error)
+           error ("cannot value-initialize array of unknown bound %qT",
+                  type);
          return error_mark_node;
        }
       gcc_assert (TREE_CODE (max_index) == INTEGER_CST);
diff --git a/gcc/testsuite/g++.dg/cpp0x/sfinae15.C 
b/gcc/testsuite/g++.dg/cpp0x/sfinae15.C
new file mode 100644
index 0000000..595ca40
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/sfinae15.C
@@ -0,0 +1,12 @@
+// PR c++/48531
+// { dg-options -std=c++0x }
+
+template<class T,
+  class = decltype(T())
+>
+char f(int);
+
+template<class>
+char (&f(...))[2];
+
+static_assert(sizeof(f<int[]>(0)) != 1, "Error");