On Wed, Jan 13, 2016 at 9:42 AM, Jan Hubicka <hubi...@ucw.cz> wrote:
> Hi,
> this patch fix wrong code with Firefox and LTO which Martin Liska tracked
> down.
> The problem is that unlike DECL_ABSTRACT_ORIGIN that always point to
> transitive
> closure of origin, BLOCK_ABSTRACT_ORIGIN can iterate. In firefox we see a
> function split by ipa-split which contains a construction we inlined from.
> Consequently, the BLOCK_ABSTRACT_ORIGIN is an another block whose
> BLOCK_ABSTRACT_ORIGIN is the ctor instead of BLOCK_ABSTRACT_ORIGIN beaing ctor
> idrectly as exxpected by inlined_polymorphic_ctor_dtor_block_p.
>
> Bootstrapped/regtested x86_64-linux, will commit it tonight if there are no
> complains. Note that the function block_origin is different from
> ultimate_block_origin used by dwarf2out because it walks abstract blocks that
> is needed, because the blocks we seek for are abstract.
>
> I think the release branches are also affected.
>
> Honza
>
> * ipa-polymorphic-call.c (block_origin): New function.
> (inlined_polymorphic_ctor_dtor_block_p,
> noncall_stmt_may_be_vtbl_ptr_store): Use it.
> Index: ipa-polymorphic-call.c
> ===================================================================
> --- ipa-polymorphic-call.c (revision 232293)
> +++ ipa-polymorphic-call.c (working copy)
> @@ -477,6 +477,20 @@ contains_type_p (tree outer_type, HOST_W
> consider_bases);
> }
>
> +/* Unlike ABSTRACT_ORIGIN, the BLOCK_ABSTRACT_ORIGIN can iterate. Look up
> + the real origin of BLOCK. */
> +
> +static tree
> +block_origin (tree block)
> +{
> + if (!BLOCK_ABSTRACT_ORIGIN (block))
> + return NULL;
> + while (TREE_CODE (block) == BLOCK && BLOCK_ABSTRACT_ORIGIN (block)
> + && BLOCK_ABSTRACT_ORIGIN (block) != block)
> + block = BLOCK_ABSTRACT_ORIGIN (block);
> + return DECL_P (block) ? DECL_ORIGIN (block) : block;
> +}
block_ultimate_origin ()?
> +
>
> /* Return a FUNCTION_DECL if BLOCK represents a constructor or destructor.
> If CHECK_CLONES is true, also check for clones of ctor/dtors. */
> @@ -484,7 +498,7 @@ contains_type_p (tree outer_type, HOST_W
> tree
> inlined_polymorphic_ctor_dtor_block_p (tree block, bool check_clones)
> {
> - tree fn = BLOCK_ABSTRACT_ORIGIN (block);
> + tree fn = block_origin (block);
> if (fn == NULL || TREE_CODE (fn) != FUNCTION_DECL)
> return NULL_TREE;
>
> @@ -1143,7 +1157,7 @@ noncall_stmt_may_be_vtbl_ptr_store (gimp
> for (tree block = gimple_block (stmt); block && TREE_CODE (block) == BLOCK;
> block = BLOCK_SUPERCONTEXT (block))
> if (BLOCK_ABSTRACT_ORIGIN (block)
> - && TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block)) == FUNCTION_DECL)
> + && TREE_CODE (block_origin (block)) == FUNCTION_DECL)
> return inlined_polymorphic_ctor_dtor_block_p (block, false);
> return (TREE_CODE (TREE_TYPE (current_function_decl)) == METHOD_TYPE
> && (DECL_CXX_CONSTRUCTOR_P (current_function_decl)
