c++: premature overload resolution [PR93085]

We can't resolve the call to foo<42> before instantiation of G, because the
template parameter of #1 has dependent type.  But we were missing that in
our dependency check, because the tree walk of DECL_TEMPLATE_PARMS doesn't
look into the types of template parameters.  So look at them directly.

gcc/cp/ChangeLog:

	PR c++/93085
	* pt.c (uses_outer_template_parms): Handle non-type and template
	template parameters specifically.

gcc/testsuite/ChangeLog:

	PR c++/93085
	* g++.dg/template/dependent-tmpl1.C: New test.

1 files changed, 16 insertions, 5 deletions

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index abd1ad4..efcbc59 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -10846,11 +10846,22 @@ uses_outer_template_parms (tree decl)
 			      &depth, NULL, /*include_nondeduced_p=*/true))
     return true;
   if (PRIMARY_TEMPLATE_P (decl)
-      && for_each_template_parm (INNERMOST_TEMPLATE_PARMS
-				 (DECL_TEMPLATE_PARMS (decl)),
-				 template_parm_outer_level,
-				 &depth, NULL, /*include_nondeduced_p=*/true))
-    return true;
+      || DECL_TEMPLATE_TEMPLATE_PARM_P (decl))
+    {
+      tree parms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (decl));
+      for (int i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
+	{
+	  tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
+	  if (TREE_CODE (parm) == PARM_DECL
+	      && for_each_template_parm (TREE_TYPE (parm),
+					 template_parm_outer_level,
+					 &depth, NULL, /*nondeduced*/true))
+	    return true;
+	  if (TREE_CODE (parm) == TEMPLATE_DECL
+	      && uses_outer_template_parms (parm))
+	    return true;
+	}
+    }
   tree ci = get_constraints (decl);
   if (ci)
     ci = CI_ASSOCIATED_CONSTRAINTS (ci);