[PATCH 9b] Don't assume that copy tables were initialized

[David Malcolm <dmalcolm at redhat dot com>]

gcc/ChangeLog:
	* cfg.c (original_copy_tables_initialized_p): New function.
	* cfg.h (original_copy_tables_initialized_p): New decl.
	* cfgrtl.c (relink_block_chain): Guard the call to
	free_original_copy_tables with a call to
	original_copy_tables_initialized_p.
---
 gcc/cfg.c    | 9 +++++++++
 gcc/cfg.h    | 1 +
 gcc/cfgrtl.c | 3 ++-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/gcc/cfg.c b/gcc/cfg.c
index 97cc755..f30b680 100644
--- a/gcc/cfg.c
+++ b/gcc/cfg.c
@@ -1094,6 +1094,15 @@ free_original_copy_tables (void)
   original_copy_bb_pool = NULL;
 }
 
+/* Return true iff we have had a call to initialize_original_copy_tables
+   without a corresponding call to free_original_copy_tables.  */
+
+bool
+original_copy_tables_initialized_p (void)
+{
+  return original_copy_bb_pool != NULL;
+}
+
 /* Removes the value associated with OBJ from table TAB.  */
 
 static void
diff --git a/gcc/cfg.h b/gcc/cfg.h
index d421d3b..b44f1e1 100644
--- a/gcc/cfg.h
+++ b/gcc/cfg.h
@@ -110,6 +110,7 @@ extern void scale_bbs_frequencies_gcov_type (basic_block *, int, gcov_type,
 extern void initialize_original_copy_tables (void);
 extern void reset_original_copy_tables (void);
 extern void free_original_copy_tables (void);
+extern bool original_copy_tables_initialized_p (void);
 extern void set_bb_original (basic_block, basic_block);
 extern basic_block get_bb_original (basic_block);
 extern void set_bb_copy (basic_block, basic_block);
diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c
index 7604346..b3b1146 100644
--- a/gcc/cfgrtl.c
+++ b/gcc/cfgrtl.c
@@ -3646,7 +3646,8 @@ relink_block_chain (bool stay_in_cfglayout_mode)
   /* Maybe reset the original copy tables, they are not valid anymore
      when we renumber the basic blocks in compact_blocks.  If we are
      are going out of cfglayout mode, don't re-allocate the tables.  */
-  free_original_copy_tables ();
+  if (original_copy_tables_initialized_p ())
+    free_original_copy_tables ();
   if (stay_in_cfglayout_mode)
     initialize_original_copy_tables ();
 
-- 
1.8.5.3