public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc r9-9456] c++: Fix folding of non-dependent BASELINKs [PR95468]
@ 2021-04-21 21:09 Patrick Palka
0 siblings, 0 replies; only message in thread
From: Patrick Palka @ 2021-04-21 21:09 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:1b265d910f27743dc3ea8e4fde6c292df220fb9f
commit r9-9456-g1b265d910f27743dc3ea8e4fde6c292df220fb9f
Author: Patrick Palka <ppalka@redhat.com>
Date: Tue Feb 23 09:40:09 2021 -0500
c++: Fix folding of non-dependent BASELINKs [PR95468]
Here, the problem ultimately seems to be that tsubst_copy_and_build,
when called with empty args as we do during non-dependent expression
folding, doesn't touch BASELINKs at all: it delegates to tsubst_copy
which then immediately exits early due to the empty args. This means
that the CAST_EXPR int(1) in the BASELINK A::condition<int(1)> never
gets folded (as part of folding of the overall CALL_EXPR), which later
causes us to crash when performing overload resolution of the rebuilt
CALL_EXPR (which is still in terms of this templated BASELINK).
This doesn't happen when condition() is a namespace-scope function
because then condition<int(1)> is represented by a TEMPLATE_ID_EXPR
rather than by a BASELINK, which does get handled directly from
tsubst_copy_and_build.
This patch fixes this issue by having tsubst_copy_and_build handle
BASELINK directly rather than delegating to tsubst_copy, so that it
processes BASELINKs even when args is empty.
gcc/cp/ChangeLog:
PR c++/95468
* pt.c (tsubst_copy_and_build) <case BASELINK>: New case, copied
over from tsubst_copy.
gcc/testsuite/ChangeLog:
PR c++/95468
* g++.dg/template/non-dependent15.C: New test.
(cherry picked from commit 5bd7afb71fca3a5a6e9f8586d86903bae1849193)
Diff:
---
gcc/cp/pt.c | 5 +++++
gcc/testsuite/g++.dg/template/non-dependent15.C | 12 ++++++++++++
2 files changed, 17 insertions(+)
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index cc40ee0bc81..d0bea4a5266 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -18787,6 +18787,11 @@ tsubst_copy_and_build (tree t,
case SCOPE_REF:
RETURN (tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
/*address_p=*/false));
+
+ case BASELINK:
+ RETURN (tsubst_baselink (t, current_nonlambda_class_type (),
+ args, complain, in_decl));
+
case ARRAY_REF:
op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
args, complain, in_decl);
diff --git a/gcc/testsuite/g++.dg/template/non-dependent15.C b/gcc/testsuite/g++.dg/template/non-dependent15.C
new file mode 100644
index 00000000000..00dfe26d6ba
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/non-dependent15.C
@@ -0,0 +1,12 @@
+// PR c++/95468
+// { dg-do compile { target c++11 } }
+
+struct A {
+ template <int N>
+ static constexpr int condition() { return N; }
+};
+
+template <int> struct B {};
+
+template <class>
+using T = B<A::condition<int(1)>()>;
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2021-04-21 21:09 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-21 21:09 [gcc r9-9456] c++: Fix folding of non-dependent BASELINKs [PR95468] Patrick Palka
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).