Hi,
On Wed, May 16 2018, Jason Merrill wrote:
> On Wed, May 16, 2018 at 6:35 AM, Martin Jambor <mjam...@suse.cz> wrote:
>> On Tue, May 15 2018, Jason Merrill wrote:
>>> In C++11 and up, the implicitly-declared copy constructor and
>>> assignment operator are deprecated if one of them, or the destructor,
>>> is user-provided. Implementing that in G++ turned up a few dodgy uses
>>> in the compiler.
>>>
>>> In general it's unsafe to copy an ipa_edge_args, because if one of the
>>> pointers is non-null you get two copies of a vec pointer, and when one
>>> of the objects is destroyed it frees the vec and leaves the other
>>> object pointing to freed memory. This specific example is safe
>>> because it only copies from an object with null pointers, but it would
>>> be better to avoid the copy. OK for trunk?
>>
>> I have had a look and found out that the function in question
>> (ipa_free_edge_args_substructures) has no uses, apparently I forgot to
>> remove it when I did the conversion of jump functions to be stored in
>> call graph edge summaries. So thanks lot for spotting this but I'd
>> prefer the following (compiled but untested) patch:
>>
>> Martin
>>
>>
>> 2018-05-16 Martin Jambor <mjam...@suse.cz>
>>
>> * ipa-prop.c (ipa_free_all_edge_args): Remove.
>> * ipa-prop.h (ipa_free_all_edge_args): Likewise.
>
> That works for me, too.
>
> Jason
OK, so after bootstrapping and testing on x86_64, I committed the patch
as obvious.
Thanks,
Martin
2018-05-16 Martin Jambor <mjam...@suse.cz>
* ipa-prop.c (ipa_free_all_edge_args): Remove.
* ipa-prop.h (ipa_free_all_edge_args): Likewise.
---
gcc/ipa-prop.c | 10 ----------
gcc/ipa-prop.h | 1 -
2 files changed, 11 deletions(-)
diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
index 38441cc49bc..19d55cda009 100644
--- a/gcc/ipa-prop.c
+++ b/gcc/ipa-prop.c
@@ -3708,16 +3708,6 @@ ipa_check_create_edge_args (void)
ipa_vr_hash_table = hash_table<ipa_vr_ggc_hash_traits>::create_ggc (37);
}
-/* Frees all dynamically allocated structures that the argument info points
- to. */
-
-void
-ipa_free_edge_args_substructures (struct ipa_edge_args *args)
-{
- vec_free (args->jump_functions);
- *args = ipa_edge_args ();
-}
-
/* Free all ipa_edge structures. */
void
diff --git a/gcc/ipa-prop.h b/gcc/ipa-prop.h
index a61e06135e3..dc45cea9c71 100644
--- a/gcc/ipa-prop.h
+++ b/gcc/ipa-prop.h
@@ -664,7 +664,6 @@ extern GTY(()) vec<ipcp_transformation_summary, va_gc>
*ipcp_transformations;
void ipa_create_all_node_params (void);
void ipa_create_all_edge_args (void);
void ipa_check_create_edge_args (void);
-void ipa_free_edge_args_substructures (struct ipa_edge_args *);
void ipa_free_all_node_params (void);
void ipa_free_all_edge_args (void);
void ipa_free_all_structures_after_ipa_cp (void);
--
2.16.3
