Re: Explicitly list all tree codes in gcc/tree-streamer.c:record_common_node

[Thomas Schwinge <thomas at codesourcery dot com>]

Hi!

On Fri, 30 Sep 2016 09:47:56 +0200, Richard Biener <richard.guenther@gmail.com> wrote:
> On Thu, Sep 29, 2016 at 4:48 PM, Thomas Schwinge
> <thomas@codesourcery.com> wrote:
> > On Mon, 19 Sep 2016 13:25:01 +0200, Richard Biener <richard.guenther@gmail.com> wrote:
> >> On Mon, Sep 19, 2016 at 1:19 PM, Thomas Schwinge
> >> <thomas@codesourcery.com> wrote:
> >> > On Mon, 19 Sep 2016 10:18:35 +0200, Richard Biener <richard.guenther@gmail.com> wrote:
> >> >> On Fri, Sep 16, 2016 at 3:32 PM, Thomas Schwinge
> >> >> <thomas@codesourcery.com> wrote:
> >> >> > --- gcc/tree-streamer.c
> >> >> > +++ gcc/tree-streamer.c
> >> >> > @@ -278,9 +278,23 @@ record_common_node (struct streamer_tree_cache_d *cache, tree node)
> >> >> >    streamer_tree_cache_append (cache, node, cache->nodes.length ());
> >> >> >
> >> >> >    if (POINTER_TYPE_P (node)
> >> >> > -      || TREE_CODE (node) == COMPLEX_TYPE
> >> >> >        || TREE_CODE (node) == ARRAY_TYPE)
> >> >> >      record_common_node (cache, TREE_TYPE (node));
> >> >> > +  else if (TREE_CODE (node) == COMPLEX_TYPE)
> >> >> > [...]
> >> >> >    else if (TREE_CODE (node) == RECORD_TYPE)
> >
> >> [looks to me we miss handling of vector type components alltogether,
> >> maybe there are no global vector type trees ...]
> >
> > Looks like it, yes.  Would a patch like the following be reasonable,
> > which explicitly lists/handles all expected tree codes, or is something
> > like that not feasible?  (That's a subset of tree codes I gathered by a
> > partial run of the GCC testsuite, and libgomp testsuite; not claiming
> > this is complete.)
> 
> I think it would be a nice thing to have indeed.
> 
> So -- I'm inclined to approve this patch ;)

After quite a bit of testing (contrib/config-list.mk, modified to run
-fself-test with -flto, to exercise the code I'm modifying), I have now
committed this to trunk in r241246:

commit 29cfc397b0ec2c953ff929d0ba57001c7018ec0c
Author: tschwinge <tschwinge@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Mon Oct 17 15:56:22 2016 +0000

    Explicitly list all tree codes in gcc/tree-streamer.c:record_common_node
    
    	gcc/
    	* tree-streamer.c (record_common_node): Explicitly list expected
    	tree codes.
    
    git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@241246 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/ChangeLog       |  5 +++++
 gcc/tree-streamer.c | 30 +++++++++++++++++++++++++-----
 2 files changed, 30 insertions(+), 5 deletions(-)

diff --git gcc/ChangeLog gcc/ChangeLog
index 86df616..9acc738 100644
--- gcc/ChangeLog
+++ gcc/ChangeLog
@@ -1,3 +1,8 @@
+2016-10-17  Thomas Schwinge  <thomas@codesourcery.com>
+
+	* tree-streamer.c (record_common_node): Explicitly list expected
+	tree codes.
+
 2016-10-17  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/77988
diff --git gcc/tree-streamer.c gcc/tree-streamer.c
index 7ea7096..2139e96 100644
--- gcc/tree-streamer.c
+++ gcc/tree-streamer.c
@@ -277,12 +277,28 @@ record_common_node (struct streamer_tree_cache_d *cache, tree node)
      in the cache as hash value.  */
   streamer_tree_cache_append (cache, node, cache->nodes.length ());
 
-  if (POINTER_TYPE_P (node)
-      || TREE_CODE (node) == COMPLEX_TYPE
-      || TREE_CODE (node) == ARRAY_TYPE)
-    record_common_node (cache, TREE_TYPE (node));
-  else if (TREE_CODE (node) == RECORD_TYPE)
+  switch (TREE_CODE (node))
     {
+    case ERROR_MARK:
+    case FIELD_DECL:
+    case FIXED_POINT_TYPE:
+    case IDENTIFIER_NODE:
+    case INTEGER_CST:
+    case INTEGER_TYPE:
+    case POINTER_BOUNDS_TYPE:
+    case REAL_TYPE:
+    case TREE_LIST:
+    case VOID_CST:
+    case VOID_TYPE:
+      /* No recursive trees.  */
+      break;
+    case ARRAY_TYPE:
+    case COMPLEX_TYPE:
+    case POINTER_TYPE:
+    case REFERENCE_TYPE:
+      record_common_node (cache, TREE_TYPE (node));
+      break;
+    case RECORD_TYPE:
       /* The FIELD_DECLs of structures should be shared, so that every
 	 COMPONENT_REF uses the same tree node when referencing a field.
 	 Pointer equality between FIELD_DECLs is used by the alias
@@ -291,6 +307,10 @@ record_common_node (struct streamer_tree_cache_d *cache, tree node)
 	 nonoverlapping_component_refs_of_decl_p).  */
       for (tree f = TYPE_FIELDS (node); f; f = TREE_CHAIN (f))
 	record_common_node (cache, f);
+      break;
+    default:
+      /* Unexpected tree code.  */
+      gcc_unreachable ();
     }
 }
 


Grüße
 Thomas