Patchwork C++ PATCH for c++/48531 (ICE with value-initialization of array)

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Submitter Jason Merrill
Date April 18, 2011, 12:49 a.m.
Message ID <4DAB8AB0.70300@redhat.com>
Download mbox | patch
Permalink /patch/91645/
State New
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Comments

Jason Merrill - April 18, 2011, 12:49 a.m.
The switch to using build_value_init for value-initialization of 
non-class types caused us to incorrectly allow functional casts to array 
type, leading to an ICE.

Tested x86_64-pc-linux-gnu, applied to trunk.
commit 4c4d50b6852b51cd6a227a09f330a086eb3b1d63
Author: Jason Merrill <jason@redhat.com>
Date:   Sat Apr 16 17:34:10 2011 -0700

    	PR c++/48531
    	* typeck2.c (build_functional_cast): Disallow array type.

Patch

diff --git a/gcc/cp/init.c b/gcc/cp/init.c
index fad7f0c..3280d9b 100644
--- a/gcc/cp/init.c
+++ b/gcc/cp/init.c
@@ -369,6 +369,8 @@  build_value_init (tree type, tsubst_flags_t complain)
 tree
 build_value_init_noctor (tree type, tsubst_flags_t complain)
 {
+  /* FIXME the class and array cases should just use digest_init once it is
+     SFINAE-enabled.  */
   if (CLASS_TYPE_P (type))
     {
       gcc_assert (!TYPE_NEEDS_CONSTRUCTING (type));
@@ -450,7 +452,9 @@  build_value_init_noctor (tree type, tsubst_flags_t complain)
 	  if (ce->value == error_mark_node)
 	    return error_mark_node;
 
-	  /* The gimplifier can't deal with a RANGE_EXPR of TARGET_EXPRs.  */
+	  /* We shouldn't have gotten here for anything that would need
+	     non-trivial initialization, and gimplify_init_ctor_preeval
+	     would need to be fixed to allow it.  */
 	  gcc_assert (TREE_CODE (ce->value) != TARGET_EXPR
 		      && TREE_CODE (ce->value) != AGGR_INIT_EXPR);
 	}
diff --git a/gcc/cp/typeck2.c b/gcc/cp/typeck2.c
index 20b47d5..f0b67f7 100644
--- a/gcc/cp/typeck2.c
+++ b/gcc/cp/typeck2.c
@@ -1534,6 +1534,15 @@  build_functional_cast (tree exp, tree parms, tsubst_flags_t complain)
   else
     type = exp;
 
+  /* We need to check this explicitly, since value-initialization of
+     arrays is allowed in other situations.  */
+  if (TREE_CODE (type) == ARRAY_TYPE)
+    {
+      if (complain & tf_error)
+	error ("functional cast to array type %qT", type);
+      return error_mark_node;
+    }
+
   if (processing_template_decl)
     {
       tree t;
diff --git a/gcc/testsuite/g++.dg/cpp0x/sfinae16.C b/gcc/testsuite/g++.dg/cpp0x/sfinae16.C
new file mode 100644
index 0000000..6470567
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/sfinae16.C
@@ -0,0 +1,17 @@ 
+// PR c++/48531
+// { dg-options -std=c++0x }
+
+template<class T,
+  class = decltype(T())
+>
+char f(int);
+
+template<class>
+double f(...);
+
+struct B2 {
+  B2(...);
+};
+
+#define SA(X) static_assert ((X), #X);
+SA(sizeof(f<B2[2]>(0)) != 1);