On 1/18/21 12:31 AM, Patrick Palka wrote:
Here after resolving the address of a template-id inside decltype, we
end up instantiating the chosen specialization from the call to
mark_used in resolve_nondeduced_context, even though only its type is
needed.
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look for
trunk?
gcc/cp/ChangeLog:
PR c++/71879
* semantics.c (finish_decltype_type): Temporarily increment
cp_unevaluated_operand during call to resolve_nondeduced_context.
gcc/testsuite/ChangeLog:
PR c++/71879
* g++.dg/cpp0x/decltype-71879.C: New test.
---
gcc/cp/semantics.c | 2 ++
gcc/testsuite/g++.dg/cpp0x/decltype-71879.C | 5 +++++
2 files changed, 7 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/decltype-71879.C
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index c8a6283b120..cad55665ce8 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -10098,7 +10098,9 @@ finish_decltype_type (tree expr, bool
id_expression_or_member_access_p,
/* The type denoted by decltype(e) is defined as follows: */
+ ++cp_unevaluated_operand;
expr = resolve_nondeduced_context (expr, complain);
+ --cp_unevaluated_operand;
Hmm, is there a reason not to have cp_unevaluated_operand set through
the whole function? We might stick 'cp_unevaluated u;' at the top of
the function and remove the existing messing with
cp_unevaluated_operand. Or assert that it's set and fix the callers to
leave it set longer.
if (invalid_nonstatic_memfn_p (input_location, expr, complain))
return error_mark_node;
diff --git a/gcc/testsuite/g++.dg/cpp0x/decltype-71879.C
b/gcc/testsuite/g++.dg/cpp0x/decltype-71879.C
new file mode 100644
index 00000000000..9da4d40ca70
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/decltype-71879.C
@@ -0,0 +1,5 @@
+// PR c++/71879
+// { dg-do compile { target c++11 } }
+
+template <class T> void f(T x) { x.fail(); }
+using R = decltype(&f<int>);
