Tested x86_64-pc-linux-gnu, applying to trunk.
-- 8< --
Here we are trying to do name lookup in a deferred instantiation of t() and
failing to find __func__. tsubst_expr already tries to instantiate members
of local classes, but was failing with the partial instantiation of generic
lambdas.
PR c++/108242
gcc/cp/ChangeLog:
* pt.cc (tsubst_expr) [TAG_DEFN]: Handle partial instantiation.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/lambda-generic-func2.C: New test.
---
gcc/cp/pt.cc | 5 ++++-
.../g++.dg/cpp1y/lambda-generic-func2.C | 18 ++++++++++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/lambda-generic-func2.C
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index ddbd73371b9..1072882e1a8 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -19341,7 +19341,10 @@ tsubst_expr (tree t, tree args, tsubst_flags_t
complain, tree in_decl)
case TAG_DEFN:
tmp = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
- if (CLASS_TYPE_P (tmp))
+ if (dependent_type_p (tmp))
+ /* This is a partial instantiation, try again when full. */
+ add_stmt (build_min (TAG_DEFN, tmp));
+ else if (CLASS_TYPE_P (tmp))
{
/* Local classes are not independent templates; they are
instantiated along with their containing function. And this
diff --git a/gcc/testsuite/g++.dg/cpp1y/lambda-generic-func2.C
b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-func2.C
new file mode 100644
index 00000000000..ed541c7812f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-func2.C
@@ -0,0 +1,18 @@
+// PR c++/108242
+// { dg-do compile { target c++14 } }
+
+template<int F>
+void my_fun()
+{
+ [&](auto) {
+ static constexpr char const* fun_name = __func__;
+ struct t
+ {
+ t() { fun_name; };
+ } t1;
+ }(12);
+}
+
+int main() {
+ my_fun<1>();
+}
base-commit: 1cc8814098bb46f9fca58a0b831fbf9a8574bdc9
--
2.31.1
