From: Cary Coutant <ccoutant@google.com>
Date: Mon, 10 Jun 2013 23:48:41 +0000 (+0000)
Subject: dwarf2out.c (hash_external_ref): Use die_symbol or signature for hash so that hash... 
X-Git-Tag: upstream/12.2.0~69275
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a5dc7f88de18ed816eb57be1ede6083528406893;p=platform%2Fupstream%2Fgcc.git

dwarf2out.c (hash_external_ref): Use die_symbol or signature for hash so that hash table traversal order is...

2013-06-10  Cary Coutant  <ccoutant@google.com>

gcc/
	* dwarf2out.c (hash_external_ref): Use die_symbol or signature
	for hash so that hash table traversal order is deterministic.

From-SVN: r199927
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 77bd5e6..703428a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2013-06-10  Cary Coutant  <ccoutant@google.com>
+
+	* dwarf2out.c (hash_external_ref): Use die_symbol or signature
+	for hash so that hash table traversal order is deterministic.
+
 2013-06-10  Michael Meissner  <meissner@linux.vnet.ibm.com>
 	    Pat Haugen <pthaugen@us.ibm.com>
 	    Peter Bergner <bergner@vnet.ibm.com>
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index b615b18..f42ad66 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -7388,7 +7388,22 @@ struct external_ref_hasher : typed_free_remove <external_ref>
 inline hashval_t
 external_ref_hasher::hash (const value_type *r)
 {
-  return htab_hash_pointer (r->type);
+  dw_die_ref die = r->type;
+  hashval_t h = 0;
+
+  /* We can't use the address of the DIE for hashing, because
+     that will make the order of the stub DIEs non-deterministic.  */
+  if (! die->comdat_type_p)
+    /* We have a symbol; use it to compute a hash.  */
+    h = htab_hash_string (die->die_id.die_symbol);
+  else
+    {
+      /* We have a type signature; use a subset of the bits as the hash.
+	 The 8-byte signature is at least as large as hashval_t.  */
+      comdat_type_node_ref type_node = die->die_id.die_type_node;
+      memcpy (&h, type_node->signature, sizeof (h));
+    }
+  return h;
 }
 
 inline bool