Re: [PATCH] c++: abi_tag attribute on templates [PR109715]

[Jason Merrill]

On 12/14/23 14:17, Patrick Palka wrote:

Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk?  Do we want to condition this on abi_check (19)?

I think we do, sadly.

-- >8 --

As with other declaration attributes, we need to look through
TEMPLATE_DECL when looking up the abi_tag attribute.

        PR c++/109715

gcc/cp/ChangeLog:

        * mangle.cc (get_abi_tags): Look through TEMPLATE_DECL.

gcc/testsuite/ChangeLog:

        * g++.dg/abi/abi-tag25.C: New test.
---
  gcc/cp/mangle.cc                     |  3 +++
  gcc/testsuite/g++.dg/abi/abi-tag25.C | 17 +++++++++++++++++
  2 files changed, 20 insertions(+)
  create mode 100644 gcc/testsuite/g++.dg/abi/abi-tag25.C

diff --git a/gcc/cp/mangle.cc b/gcc/cp/mangle.cc
index 0684f0e6038..1fbd879c116 100644
--- a/gcc/cp/mangle.cc
+++ b/gcc/cp/mangle.cc
@@ -527,6 +527,9 @@ get_abi_tags (tree t)
    if (!t || TREE_CODE (t) == NAMESPACE_DECL)
      return NULL_TREE;

+ if (TREE_CODE (t) == TEMPLATE_DECL && DECL_TEMPLATE_RESULT (t))

+    t = DECL_TEMPLATE_RESULT (t);
+
    if (DECL_P (t) && DECL_DECLARES_TYPE_P (t))
      t = TREE_TYPE (t);

diff --git a/gcc/testsuite/g++.dg/abi/abi-tag25.C b/gcc/testsuite/g++.dg/abi/abi-tag25.C

new file mode 100644
index 00000000000..9847f0dccc8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/abi-tag25.C
@@ -0,0 +1,17 @@
+// PR c++/109715
+// { dg-do compile { target c++11 } }
+
+template<class T>
+[[gnu::abi_tag("foo")]] void fun() { }
+
+template void fun<int>();
+
+#if __cpp_variable_templates
+template<class T>
+[[gnu::abi_tag("foo")]] int var = 0;
+
+template int var<int>;
+#endif
+
+// { dg-final { scan-assembler "_Z3funB3fooIiEvv" } }
+// { dg-final { scan-assembler "_Z3varB3fooIiE" { target c++14 } } }