mirror/gcc
2
0
Fork 0
mirror of git://gcc.gnu.org/git/gcc.git synced 2025-02-27 16:55:56 +08:00
Code Issues Packages Projects Releases Wiki Activity

c++, abi: Fix abi_tag attribute handling [PR98481]

Browse Source 
In GCC10 cp_walk_subtrees has been changed to walk template arguments.
As the following testcase, that changed the mangling of some functions.
I believe the previous behavior that find_abi_tags_r doesn't recurse into
template args has been the correct one, but setting *walk_subtrees = 0
for the types and handling the types subtree walking manually in
find_abi_tags_r looks too hard, there are a lot of subtrees and details what
should and shouldn't be walked, both in tree.c (walk_type_fields there,
which is static) and in cp_walk_subtrees itself.

The following patch abuses the fact that *walk_subtrees is an int to
tell cp_walk_subtrees it shouldn't walk the template args.

Co-authored-by: Jason Merrill <jason@redhat.com>

gcc/cp/ChangeLog:

	PR c++/98481
	* class.c (find_abi_tags_r): Set *walk_subtrees to 2 instead of 1
	for types.
	(mark_abi_tags_r): Likewise.
	* decl2.c (min_vis_r): Likewise.
	* tree.c (cp_walk_subtrees): If *walk_subtrees_p is 2, look through
	typedefs.

gcc/testsuite/ChangeLog:

	PR c++/98481
	* g++.dg/abi/abi-tag24.C: New test.
This commit is contained in:
Jakub Jelinek 2021-01-07 17:47:18 +01:00 committed by Jason Merrill
parent 8c09b788a9
commit 3dd0d3ee1d
4 changed files with 45 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
gcc/cp/class.c
View File

@ -1507,6 +1507,10 @@ mark_or_check_tags (tree t, tree *tp, abi_tag_data *p, bool val)
static tree
find_abi_tags_r (tree *tp, int *walk_subtrees, void *data)
{
if (TYPE_P (*tp) && *walk_subtrees == 1)
/* Tell cp_walk_subtrees to look though typedefs. */
*walk_subtrees = 2;
if (!OVERLOAD_TYPE_P (*tp))
return NULL_TREE;
@ -1527,6 +1531,10 @@ find_abi_tags_r (tree *tp, int *walk_subtrees, void *data)
static tree
mark_abi_tags_r (tree *tp, int *walk_subtrees, void *data)
{
if (TYPE_P (*tp) && *walk_subtrees == 1)
/* Tell cp_walk_subtrees to look though typedefs. */
*walk_subtrees = 2;
if (!OVERLOAD_TYPE_P (*tp))
return NULL_TREE;

7
gcc/cp/decl2.c
View File

@ -2358,9 +2358,6 @@ min_vis_r (tree *tp, int *walk_subtrees, void *data)
int this_vis = VISIBILITY_DEFAULT;
if (! TYPE_P (*tp))
*walk_subtrees = 0;
else if (typedef_variant_p (*tp))
/* Look through typedefs despite cp_walk_subtrees. */
this_vis = type_visibility (DECL_ORIGINAL_TYPE (TYPE_NAME (*tp)));
else if (OVERLOAD_TYPE_P (*tp)
&& !TREE_PUBLIC (TYPE_MAIN_DECL (*tp)))
{
@ -2379,6 +2376,10 @@ min_vis_r (tree *tp, int *walk_subtrees, void *data)
if (this_vis > *vis_p)
*vis_p = this_vis;
/* Tell cp_walk_subtrees to look through typedefs. */
if (*walk_subtrees == 1)
*walk_subtrees = 2;
return NULL;
}

22
gcc/cp/tree.c
View File

@ -5146,16 +5146,26 @@ cp_walk_subtrees (tree *tp, int *walk_subtrees_p, walk_tree_fn func,
if (TYPE_P (*tp))
{
/* Walk into template args without looking through typedefs. */
if (tree ti = TYPE_TEMPLATE_INFO_MAYBE_ALIAS (*tp))
WALK_SUBTREE (TI_ARGS (ti));
/* Don't look through typedefs; walk_tree_fns that want to look through
typedefs (like min_vis_r) need to do that themselves. */
if (typedef_variant_p (*tp))
/* If *WALK_SUBTREES_P is 1, we're interested in the syntactic form of
the argument, so don't look through typedefs, but do walk into
template arguments for alias templates (and non-typedefed classes).
If *WALK_SUBTREES_P > 1, we're interested in type identity or
equivalence, so look through typedefs, ignoring template arguments for
alias templates, and walk into template args of classes.
See find_abi_tags_r for an example of setting *WALK_SUBTREES_P to 2
when that's the behavior the walk_tree_fn wants. */
if (*walk_subtrees_p == 1 && typedef_variant_p (*tp))
{
if (tree ti = TYPE_ALIAS_TEMPLATE_INFO (*tp))
WALK_SUBTREE (TI_ARGS (ti));
*walk_subtrees_p = 0;
return NULL_TREE;
}
if (tree ti = TYPE_TEMPLATE_INFO (*tp))
WALK_SUBTREE (TI_ARGS (ti));
}
/* Not one of the easy cases. We must explicitly go through the

17
gcc/testsuite/g++.dg/abi/abi-tag24.C Normal file
View File

@ -0,0 +1,17 @@
// PR c++/98481
// { dg-do compile { target c++11 } }
inline namespace N __attribute ((__abi_tag__ ("myabi")))
{
struct A {};
}
template <typename T>
struct B { typedef int size_type; };
struct S1 { B<A>::size_type foo () const { return 1; } };
struct S2 { B<A>::size_type foo () const; };
int S2::foo () const { return 2; }
int (S1::*f1) () const = &S1::foo;
int (S2::*f2) () const = &S2::foo;
// { dg-final { scan-assembler "_ZNK2S13fooEv" } }
// { dg-final { scan-assembler "_ZNK2S23fooEv" } }
// { dg-final { scan-assembler-not "_ZNK2S13fooB5myabiEv" } }