This bug talks about ICEs trying to capture a VLA by value. We don't
support that, but we can give a more helpful error. In the comments
Paolo also noticed that with the new support for capture by reference,
we wrongly warn about returning a reference to the captured variable.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit e88823b454079098df61d1701ac0c7b59a96b758
Author: Jason Merrill <ja...@redhat.com>
Date: Thu May 9 22:15:22 2013 -0400
PR c++/55149
* semantics.c (add_capture): Error rather than abort on copy
capture of VLA.
* typeck.c (maybe_warn_about_returning_address_of_local): Don't
warn about capture proxy.
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 3e1a0bf..d0db10a 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -9463,9 +9463,12 @@ add_capture (tree lambda, tree id, tree initializer, bool by_reference_p,
type = lambda_capture_field_type (initializer, explicit_init_p);
if (array_of_runtime_bound_p (type))
{
+ if (!by_reference_p)
+ error ("array of runtime bound cannot be captured by copy, "
+ "only by reference");
+
/* For a VLA, we capture the address of the first element and the
maximum index, and then reconstruct the VLA for the proxy. */
- gcc_assert (by_reference_p);
tree elt = cp_build_array_ref (input_location, initializer,
integer_zero_node, tf_warning_or_error);
tree ctype = vla_capture_type (type);
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index df5fc4a..b8ea555 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -8140,6 +8140,7 @@ maybe_warn_about_returning_address_of_local (tree retval)
if (DECL_P (whats_returned)
&& DECL_NAME (whats_returned)
&& DECL_FUNCTION_SCOPE_P (whats_returned)
+ && !is_capture_proxy (whats_returned)
&& !(TREE_STATIC (whats_returned)
|| TREE_PUBLIC (whats_returned)))
{
diff --git a/gcc/testsuite/g++.dg/cpp1y/vla5.C b/gcc/testsuite/g++.dg/cpp1y/vla5.C
new file mode 100644
index 0000000..1f6da29
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/vla5.C
@@ -0,0 +1,8 @@
+// PR c++/55149
+// { dg-options -std=c++1y }
+
+void test(int n) {
+ int r[n];
+ [&r]() { return r + 0; };
+ [r]() { return r + 0; }; // { dg-error "captured by copy" }
+}
