Hi,
This patch fixes c++/21113 which reports that the C++ frontend does not
forbid jumps into the scope of identifiers with variably-modified types.
The patch simply augments decl_jump_unsafe() to disallow jumping into
blocks that initialize variably-modified decls.
I bootstrapped and regtested this change on x86_64-unknown-linux-gnu.
2014-04-03 Patrick Palka <patr...@parcs.ath.cx>
PR c++/21113
* decl.c (decl_jump_unsafe): Consider variably-modified decls.
---
gcc/cp/decl.c | 5 ++---
gcc/testsuite/g++.dg/ext/vla14.C | 23 +++++++++++++++++++++++
2 files changed, 25 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/ext/vla14.C
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 5bd33c5..6571af5 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -2785,9 +2785,8 @@ decl_jump_unsafe (tree decl)
|| type == error_mark_node)
return 0;
- type = strip_array_types (type);
-
- if (DECL_NONTRIVIALLY_INITIALIZED_P (decl))
+ if (DECL_NONTRIVIALLY_INITIALIZED_P (decl)
+ || variably_modified_type_p (type, NULL_TREE))
return 2;
if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (decl)))
diff --git a/gcc/testsuite/g++.dg/ext/vla14.C b/gcc/testsuite/g++.dg/ext/vla14.C
new file mode 100644
index 0000000..278cb63
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/vla14.C
@@ -0,0 +1,23 @@
+// PR c++/21113
+// { dg-options "" }
+
+void
+f (int n)
+{
+ goto label; // { dg-error "from here" }
+ int a[n]; // { dg-error "crosses initialization" }
+label: // { dg-error "jump to label" }
+ ;
+}
+
+void
+g (int n)
+{
+ switch (1)
+ {
+ case 1:
+ int (*a)[n]; // { dg-error "crosses initialization" }
+ default: // { dg-error "jump to case label" }
+ ;
+ }
+}
--
1.9.1
