My change to rationalize the *_constant_value functions broke this
testcase, because we were no longer replacing the reference to the array
with its constant value. Fixed by using maybe_constant_value instead.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit 00557979b84dabd18eb7cf46cb20bed9cf9bd7f6
Author: Jason Merrill <ja...@redhat.com>
Date: Fri Jun 5 16:19:11 2015 -0400
PR c++/66387
* semantics.c (process_outer_var_ref): Make sure the value is
actually constant before returning it.
* typeck.c (cp_build_array_ref): Allow subscripting non-lvalue
array.
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 650ef4c..59ec9047 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -3128,7 +3128,11 @@ process_outer_var_ref (tree decl, tsubst_flags_t complain)
form, so wait until instantiation time. */
return decl;
else if (decl_constant_var_p (decl))
- return scalar_constant_value (decl);
+ {
+ tree t = maybe_constant_value (convert_from_reference (decl));
+ if (TREE_CONSTANT (t))
+ return t;
+ }
}
if (parsing_nsdmi ())
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 6c4b038..5b09b73 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -3141,15 +3141,6 @@ cp_build_array_ref (location_t loc, tree array, tree idx,
return error_mark_node;
}
- if (!lvalue_p (array))
- {
- if (complain & tf_error)
- pedwarn (loc, OPT_Wpedantic,
- "ISO C++ forbids subscripting non-lvalue array");
- else
- return error_mark_node;
- }
-
/* Note in C++ it is valid to subscript a `register' array, since
it is valid to take the address of something with that
storage specification. */
diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-const5.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-const5.C
new file mode 100644
index 0000000..cba0370
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-const5.C
@@ -0,0 +1,16 @@
+// PR c++/66387
+// { dg-do compile { target c++11 } }
+
+template <typename T>
+void
+bar (T x)
+{
+ x ();
+}
+
+void
+foo ()
+{
+ constexpr int a[1] = { 1 };
+ bar ([&]{ return a[0]; });
+}
