From 19ac327de421fe05916e234e3450e6e1cc5c935c Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Mon, 12 Feb 2024 21:00:53 -0500
Subject: [PATCH] c++: variable partial spec redeclaration [PR113612]
If register_specialization finds a previous declaration and throws the new
one away, we shouldn't still add the new one to
DECL_TEMPLATE_SPECIALIZATIONS.
PR c++/113612
gcc/cp/ChangeLog:
* pt.cc (process_partial_specialization): Return early
on redeclaration.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/var-templ85.C: New test.
---
gcc/cp/pt.cc | 11 ++++++++---
gcc/testsuite/g++.dg/cpp1y/var-templ85.C | 6 ++++++
2 files changed, 14 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ85.C
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 475f2181cc49..2803824d11e1 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -5417,9 +5417,14 @@ process_partial_specialization (tree decl)
}
if (VAR_P (decl))
- /* We didn't register this in check_explicit_specialization so we could
- wait until the constraints were set. */
- decl = register_specialization (decl, maintmpl, specargs, false, 0);
+ {
+ /* We didn't register this in check_explicit_specialization so we could
+ wait until the constraints were set. */
+ tree reg = register_specialization (decl, maintmpl, specargs, false, 0);
+ if (reg != decl)
+ /* Redeclaration. */
+ return reg;
+ }
else
associate_classtype_constraints (type);
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ85.C b/gcc/testsuite/g++.dg/cpp1y/var-templ85.C
new file mode 100644
index 000000000000..33c24e0c2844
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ85.C
@@ -0,0 +1,6 @@
+// PR c++/113612
+// { dg-do compile { target c++14 } }
+
+template <typename T> T t;
+template <typename T> extern T *t<T *>;
+template <typename T> T *t<T *> = t<int>;
--
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