From 2e66e53b1efb98f5cf6b0a123990c1ca999affd7 Mon Sep 17 00:00:00 2001
From: Nathan Sidwell <nathan@acm.org>
Date: Thu, 24 Sep 2020 06:17:00 -0700
Subject: [PATCH] c++: local-decls are never member fns [PR97186]

This fixes an ICE in noexcept instantiation.  It was presuming
functions always have template_info, but that changed with my
DECL_LOCAL_DECL_P changes.  Fortunately DECL_LOCAL_DECL_P fns are
never member fns, so we don't need to go fishing out a this pointer.

Also I realized I'd misnamed local10.C, so renaming it local-fn3.C,
and while there adding the effective-target lto that David E pointed
out was missing.

	PR c++/97186
	gcc/cp/
	* pt.c (maybe_instantiate_noexcept): Local externs are never
	member fns.
	gcc/testsuite/
	* g++.dg/template/local10.C: Rename ...
	* g++.dg/template/local-fn3.C: .. here.  Require lto.
	* g++.dg/template/local-fn4.C: New.
---
 gcc/cp/pt.c                                         | 21 +++++++++++++--------
 .../g++.dg/template/{local10.C => local-fn3.C}      |  2 ++
 gcc/testsuite/g++.dg/template/local-fn4.C           | 21 +++++++++++++++++++++
 3 files changed, 36 insertions(+), 8 deletions(-)
 rename gcc/testsuite/g++.dg/template/{local10.C => local-fn3.C} (87%)
 create mode 100644 gcc/testsuite/g++.dg/template/local-fn4.C

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 1ec039d..62e8509 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -25397,15 +25397,20 @@ maybe_instantiate_noexcept (tree fn, tsubst_flags_t complain)
 	  push_deferring_access_checks (dk_no_deferred);
 	  input_location = DECL_SOURCE_LOCATION (fn);
 
-	  /* If needed, set current_class_ptr for the benefit of
-	     tsubst_copy/PARM_DECL.  */
-	  tree tdecl = DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (fn));
-	  if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tdecl))
+	  if (!DECL_LOCAL_DECL_P (fn))
 	    {
-	      tree this_parm = DECL_ARGUMENTS (tdecl);
-	      current_class_ptr = NULL_TREE;
-	      current_class_ref = cp_build_fold_indirect_ref (this_parm);
-	      current_class_ptr = this_parm;
+	      /* If needed, set current_class_ptr for the benefit of
+		 tsubst_copy/PARM_DECL.  The exception pattern will
+		 refer to the parm of the template, not the
+		 instantiation.  */
+	      tree tdecl = DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (fn));
+	      if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tdecl))
+		{
+		  tree this_parm = DECL_ARGUMENTS (tdecl);
+		  current_class_ptr = NULL_TREE;
+		  current_class_ref = cp_build_fold_indirect_ref (this_parm);
+		  current_class_ptr = this_parm;
+		}
 	    }
 
 	  /* If this function is represented by a TEMPLATE_DECL, then
diff --git a/gcc/testsuite/g++.dg/template/local10.C b/gcc/testsuite/g++.dg/template/local-fn3.C
similarity index 87%
rename from gcc/testsuite/g++.dg/template/local10.C
rename to gcc/testsuite/g++.dg/template/local-fn3.C
index a2ffc1e..2affe23 100644
--- a/gcc/testsuite/g++.dg/template/local10.C
+++ b/gcc/testsuite/g++.dg/template/local-fn3.C
@@ -1,4 +1,6 @@
 // PR c++/97171
+
+// { dg-require-effective-target lto }
 // { dg-additional-options -flto }
 
 template <typename _UnaryOperation>
diff --git a/gcc/testsuite/g++.dg/template/local-fn4.C b/gcc/testsuite/g++.dg/template/local-fn4.C
new file mode 100644
index 0000000..4699012
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/local-fn4.C
@@ -0,0 +1,21 @@
+// PR c++/97186
+// ICE in exception spec substitution
+
+
+template <class GG>
+struct no {
+  static void
+  tg ()
+  {
+    void
+      hk () noexcept (tg); // { dg-error "convert" }
+
+    hk ();
+  }
+};
+
+void
+os ()
+{
+  no<int> ().tg ();
+}
-- 
2.7.4