From 92812757648109dc6cd35a52374ab3f6e9f44f78 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Tue, 11 Jun 2019 08:40:08 -0400
Subject: [PATCH] gdbhooks.py (TreePrinter.to_string): Recognize ggc_free'd
 memory.

	* gdbhooks.py (TreePrinter.to_string): Recognize ggc_free'd memory.

	* tree.c (get_tree_code_name): Likewise.
	* print-tree.c (print_node): Only briefly print a node with an
	invalid code.

From-SVN: r272150
---
 gcc/ChangeLog    |  7 +++++++
 gcc/gdbhooks.py  |  3 +++
 gcc/print-tree.c | 16 +++++++++-------
 gcc/tree.c       |  6 +++++-
 4 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 66e45395da8..f115982cf1d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2019-06-11  Jason Merrill  <jason@redhat.com>
+
+	* gdbhooks.py (TreePrinter.to_string): Recognize ggc_free'd memory.
+	* tree.c (get_tree_code_name): Likewise.
+	* print-tree.c (print_node): Only briefly print a node with an
+	invalid code.
+
 2019-06-11  Jakub Jelinek  <jakub@redhat.com>
 
 	PR bootstrap/90819
diff --git a/gcc/gdbhooks.py b/gcc/gdbhooks.py
index 39f5c4772f9..e08208e1533 100644
--- a/gcc/gdbhooks.py
+++ b/gcc/gdbhooks.py
@@ -222,6 +222,9 @@ class TreePrinter:
         # extern const enum tree_code_class tree_code_type[];
         # #define TREE_CODE_CLASS(CODE)	tree_code_type[(int) (CODE)]
 
+        if val_TREE_CODE == 0xa5a5:
+            return '<ggc_freed 0x%x>' % intptr(self.gdbval)
+
         val_tree_code_type = gdb.parse_and_eval('tree_code_type')
         val_tclass = val_tree_code_type[val_TREE_CODE]
 
diff --git a/gcc/print-tree.c b/gcc/print-tree.c
index 81b66a1891b..f69a2c26679 100644
--- a/gcc/print-tree.c
+++ b/gcc/print-tree.c
@@ -233,6 +233,15 @@ print_node (FILE *file, const char *prefix, tree node, int indent,
     return;
 
   code = TREE_CODE (node);
+
+  /* It is unsafe to look at any other fields of a node with ERROR_MARK or
+     invalid code.  */
+  if (code == ERROR_MARK || code >= MAX_TREE_CODES)
+    {
+      print_node_brief (file, prefix, node, indent);
+      return;
+    }
+
   tclass = TREE_CODE_CLASS (code);
 
   /* Don't get too deep in nesting.  If the user wants to see deeper,
@@ -251,13 +260,6 @@ print_node (FILE *file, const char *prefix, tree node, int indent,
       return;
     }
 
-  /* It is unsafe to look at any other fields of an ERROR_MARK node.  */
-  if (code == ERROR_MARK)
-    {
-      print_node_brief (file, prefix, node, indent);
-      return;
-    }
-
   /* Allow this function to be called if the table is not there.  */
   if (table)
     {
diff --git a/gcc/tree.c b/gcc/tree.c
index 5d955535acc..e879f15a841 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -13450,7 +13450,11 @@ get_tree_code_name (enum tree_code code)
   const char *invalid = "<invalid tree code>";
 
   if (code >= MAX_TREE_CODES)
-    return invalid;
+    {
+      if (code == 0xa5a5)
+	return "ggc_freed";
+      return invalid;
+    }
 
   return tree_code_name[code];
 }
-- 
2.30.2