From: Jason Merrill <jason@redhat.com>
Date: Wed, 14 Apr 2021 18:14:31 +0000 (-0400)
Subject: c++: premature overload resolution redux [PR100078]
X-Git-Tag: basepoints/gcc-12~75
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=00a2774923c1dc5666cd26bb9b8c37b1b7dd689d;p=thirdparty%2Fgcc.git

c++: premature overload resolution redux [PR100078]

My patch for PR93085 didn't consider that a default template argument can
also make a template dependent.

gcc/cp/ChangeLog:

	PR c++/100078
	PR c++/93085
	* pt.c (uses_outer_template_parms): Also look at default
	template argument.

gcc/testsuite/ChangeLog:

	PR c++/100078
	* g++.dg/template/dependent-tmpl2.C: New test.
---

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index f488a5a8c120..0f119a552720 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -10856,6 +10856,7 @@ uses_outer_template_parms (tree decl)
       for (int i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
 	{
 	  tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
+	  tree defarg = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
 	  if (TREE_CODE (parm) == PARM_DECL
 	      && for_each_template_parm (TREE_TYPE (parm),
 					 template_parm_outer_level,
@@ -10864,6 +10865,10 @@ uses_outer_template_parms (tree decl)
 	  if (TREE_CODE (parm) == TEMPLATE_DECL
 	      && uses_outer_template_parms (parm))
 	    return true;
+	  if (defarg
+	      && for_each_template_parm (defarg, template_parm_outer_level,
+					 &depth, NULL, /*nondeduced*/true))
+	    return true;
 	}
     }
   tree ci = get_constraints (decl);
diff --git a/gcc/testsuite/g++.dg/template/dependent-tmpl2.C b/gcc/testsuite/g++.dg/template/dependent-tmpl2.C
new file mode 100644
index 000000000000..040ddb47ee61
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/dependent-tmpl2.C
@@ -0,0 +1,10 @@
+// PR c++/100078
+// { dg-do compile { target c++11 } }
+
+template <bool> struct enable_if;
+template <typename Data> struct HashMapBucket {
+  template <typename T = Data>
+  static typename enable_if<T ::value>::type selectStructure() {
+    selectStructure();
+  }
+};