From: Jason Merrill <jason@redhat.com>
Date: Mon, 5 Apr 2021 18:26:03 +0000 (-0400)
Subject: c++: enum in generic lambda in template [PR95317]
X-Git-Tag: basepoints/gcc-12~264
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9f4c41147a41d08a74990eafe69a1064a3c13435;p=thirdparty%2Fgcc.git

c++: enum in generic lambda in template [PR95317]

Here we weren't instantiating the enumerators because the arglist still had
the template parameter for the generic lambda, so looking one up failed.  We
need to instantiate if the non-lambda enclosing scope is non-dependent.

gcc/cp/ChangeLog:

	PR c++/95317
	* pt.c (lookup_template_class_1): Do tsubst_enum when
	tsubsting a generic lambda.

gcc/testsuite/ChangeLog:

	PR c++/95317
	* g++.dg/cpp1y/lambda-generic-enum1.C: New test.
---

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index d6a8ede386da..41bc633cfcea 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -10173,7 +10173,8 @@ lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
 	= tree_cons (arglist, t,
 		     DECL_TEMPLATE_INSTANTIATIONS (found));
 
-      if (TREE_CODE (template_type) == ENUMERAL_TYPE && !is_dependent_type
+      if (TREE_CODE (template_type) == ENUMERAL_TYPE
+	  && !uses_template_parms (current_nonlambda_scope ())
 	  && !DECL_ALIAS_TEMPLATE_P (gen_tmpl))
 	/* Now that the type has been registered on the instantiations
 	   list, we set up the enumerators.  Because the enumeration
diff --git a/gcc/testsuite/g++.dg/cpp1y/lambda-generic-enum1.C b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-enum1.C
new file mode 100644
index 000000000000..de15443bfcff
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-enum1.C
@@ -0,0 +1,10 @@
+// PR c++/95317
+// { dg-do compile { target c++14 } }
+
+template <typename> void fn1() {
+  [](auto) {
+    enum { VALUE };
+    VALUE;
+  };
+}
+int main() { fn1<void>; }