Hi!
During review of Martin's -fsanitize-use-after-scope patch, I've noticed
what I believe is a bug in #pragma acc declare support.
In particular, the oacc_declare_returns has been added next to the CLOBBER
additions, but the clobbers are guarded with many conditions, e.g. aren't
emitted with -fstack-reuse=none and many other conditions.
I believe the additions to that data structure aren't guarded by these
conditions, it is just for VAR_DECLs that aren't is_global_var and have
current_function_decl context.
I haven't tested this patch (can bootstrap/regtest it), but don't have time
to try to write a testcase for all the cases where the conditions matter.
2016-10-07 Jakub Jelinek <ja...@redhat.com>
* gimplify.c (gimplify_bind_expr): Handle oacc_declare_returns
even for -fstack-reuse=none, or for volatile vars etc.
--- gcc/gimplify.c.jj 2016-09-26 12:06:46.000000000 +0200
+++ gcc/gimplify.c 2016-10-07 14:11:09.299624104 +0200
@@ -1192,21 +1192,24 @@ gimplify_bind_expr (tree *expr_p, gimple
{
if (TREE_CODE (t) == VAR_DECL
&& !is_global_var (t)
- && DECL_CONTEXT (t) == current_function_decl
- && !DECL_HARD_REGISTER (t)
- && !TREE_THIS_VOLATILE (t)
- && !DECL_HAS_VALUE_EXPR_P (t)
- /* Only care for variables that have to be in memory. Others
- will be rewritten into SSA names, hence moved to the top-level. */
- && !is_gimple_reg (t)
- && flag_stack_reuse != SR_NONE)
+ && DECL_CONTEXT (t) == current_function_decl)
{
- tree clobber = build_constructor (TREE_TYPE (t), NULL);
- gimple *clobber_stmt;
- TREE_THIS_VOLATILE (clobber) = 1;
- clobber_stmt = gimple_build_assign (t, clobber);
- gimple_set_location (clobber_stmt, end_locus);
- gimplify_seq_add_stmt (&cleanup, clobber_stmt);
+ if (!DECL_HARD_REGISTER (t)
+ && !TREE_THIS_VOLATILE (t)
+ && !DECL_HAS_VALUE_EXPR_P (t)
+ /* Only care for variables that have to be in memory. Others
+ will be rewritten into SSA names, hence moved to the
+ top-level. */
+ && !is_gimple_reg (t)
+ && flag_stack_reuse != SR_NONE)
+ {
+ tree clobber = build_constructor (TREE_TYPE (t), NULL);
+ gimple *clobber_stmt;
+ TREE_THIS_VOLATILE (clobber) = 1;
+ clobber_stmt = gimple_build_assign (t, clobber);
+ gimple_set_location (clobber_stmt, end_locus);
+ gimplify_seq_add_stmt (&cleanup, clobber_stmt);
+ }
if (flag_openacc && oacc_declare_returns != NULL)
{
Jakub
