Explicitly list all tree codes in gcc/tree-streamer.c:record_common_node (was: [PR lto/77458] Avoid ICE in offloading with differing _FloatN, _FloatNx types)

[Thomas Schwinge]

Hi Richard!

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.)

commit f28dd9618be8a26c6a75ee089f1755e4e0281106
Author: Thomas Schwinge <thomas@codesourcery.com>
Date:   Thu Sep 29 16:35:19 2016 +0200

    Explicitly list all tree codes in gcc/tree-streamer.c:record_common_node
---
 gcc/tree-streamer.c | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git gcc/tree-streamer.c gcc/tree-streamer.c
index 6ada89a..8567a81 100644
--- gcc/tree-streamer.c
+++ gcc/tree-streamer.c
@@ -303,17 +303,32 @@ 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) == ARRAY_TYPE)
-    record_common_node (cache, TREE_TYPE (node));
-  else if (TREE_CODE (node) == COMPLEX_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 recursion.  */
+      break;
+    case POINTER_TYPE:
+    case REFERENCE_TYPE:
+    case ARRAY_TYPE:
+      record_common_node (cache, TREE_TYPE (node));
+      break;
+    case COMPLEX_TYPE:
       /* Verify that a complex type's component type (node_type) has been
 	 handled already (and we thus don't need to recurse here).  */
       verify_common_node_recorded (cache, TREE_TYPE (node));
-    }
-  else if (TREE_CODE (node) == RECORD_TYPE)
-    {
+      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
@@ -322,6 +337,9 @@ 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:
+      gcc_unreachable ();
     }
 }
 


Grüße
 Thomas