From 5770bbac66da20acd60a488430dff494db6606b4 Mon Sep 17 00:00:00 2001
From: Nathan Sidwell <nathan@acm.org>
Date: Tue, 20 Mar 2018 15:57:30 +0000
Subject: [PATCH] [PR c++/84970] lookup marking

https://gcc.gnu.org/ml/gcc-patches/2018-03/msg00973.html
	PR c++/84970
	* cp-tree.h (lookup_list_keep): Declare.
	* tree.c (lookup_list_keep): New, broken out of ...
	(build_min): ... here.  Call it.
	* decl.c (cp_finish_decl): Call lookup_list_keep.

	PR c++/84970
	* g++.dg/lookup/pr84970.C: New.

From-SVN: r258685
---
 gcc/cp/ChangeLog                      |  8 ++++++++
 gcc/cp/cp-tree.h                      |  1 +
 gcc/cp/decl.c                         |  6 +++++-
 gcc/cp/tree.c                         | 18 +++++++++++++++---
 gcc/testsuite/ChangeLog               |  5 +++++
 gcc/testsuite/g++.dg/lookup/pr84970.C | 21 +++++++++++++++++++++
 6 files changed, 55 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/lookup/pr84970.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index fd7329f0622..7ce79d3862b 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2018-03-20  Nathan Sidwell  <nathan@acm.org>
+
+	PR c++/84970
+	* cp-tree.h (lookup_list_keep): Declare.
+	* tree.c (lookup_list_keep): New, broken out of ...
+	(build_min): ... here.  Call it.
+	* decl.c (cp_finish_decl): Call lookup_list_keep.
+
 2018-03-19  Jason Merrill  <jason@redhat.com>
 
 	PR c++/84937 - ICE with class deduction and auto.
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 727822e36da..077ef2d13f9 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -7012,6 +7012,7 @@ extern tree lookup_add				(tree fns, tree lookup);
 extern tree lookup_maybe_add			(tree fns, tree lookup,
 						 bool deduping);
 extern void lookup_keep				(tree lookup, bool keep);
+extern void lookup_list_keep			(tree list, bool keep);
 extern int is_overloaded_fn			(tree) ATTRIBUTE_PURE;
 extern bool really_overloaded_fn		(tree) ATTRIBUTE_PURE;
 extern tree dependent_name			(tree);
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 546468bf79f..5f181a5da72 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7034,7 +7034,11 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
 	}
 
       if (init)
-	DECL_INITIAL (decl) = init;
+	{
+	  if (TREE_CODE (init) == TREE_LIST)
+	    lookup_list_keep (init, true);
+	  DECL_INITIAL (decl) = init;
+	}
       if (dep_init)
 	{
 	  retrofit_lang_decl (decl);
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index 90fbe183b97..5993633cbe5 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -2436,6 +2436,20 @@ lookup_keep (tree lookup, bool keep)
     ovl_used (lookup);
 }
 
+/* LIST is a TREE_LIST whose TREE_VALUEs may be OVERLOADS that need
+   keeping, or may be ignored.  */
+
+void
+lookup_list_keep (tree list, bool keep)
+{
+  for (; list; list = TREE_CHAIN (list))
+    {
+      tree v = TREE_VALUE (list);
+      if (TREE_CODE (v) == OVERLOAD)
+	lookup_keep (v, keep);
+    }
+}
+
 /* Returns nonzero if X is an expression for a (possibly overloaded)
    function.  If "f" is a function or function template, "f", "c->f",
    "c.f", "C::f", and "f<int>" will all be considered possibly
@@ -3315,9 +3329,7 @@ build_min (enum tree_code code, tree tt, ...)
 
   if (code == CAST_EXPR)
     /* The single operand is a TREE_LIST, which we have to check.  */
-    for (tree v = TREE_OPERAND (t, 0); v; v = TREE_CHAIN (v))
-      if (TREE_CODE (TREE_VALUE (v)) == OVERLOAD)
-	lookup_keep (TREE_VALUE (v), true);
+    lookup_list_keep (TREE_OPERAND (t, 0), true);
 
   return t;
 }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f88a09842fa..14c775ba191 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-03-20  Nathan Sidwell  <nathan@acm.org>
+
+	PR c++/84970
+	* g++.dg/lookup/pr84970.C: New.
+
 2018-03-20  Richard Biener  <rguenther@suse.de>
 
 	PR target/84986
diff --git a/gcc/testsuite/g++.dg/lookup/pr84970.C b/gcc/testsuite/g++.dg/lookup/pr84970.C
new file mode 100644
index 00000000000..ad02248d75f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lookup/pr84970.C
@@ -0,0 +1,21 @@
+// PR c++/84970 ICE with deferred initializer
+
+namespace bob {
+  void a();
+}
+using namespace bob;
+
+void a (int);
+
+template <typename b>
+void *x (b)
+{
+  void (*c)(b) (a);
+
+  return (void *)c;
+}
+
+void d () {
+  x (1);
+}
+