2011/3/24 Kai Tietz <ktiet...@googlemail.com>:
> 2011/3/24 Jason Merrill <ja...@redhat.com>:
>> On 03/24/2011 06:06 PM, Kai Tietz wrote:
>>>
>>> +/* Compare two attributes for identity. Return true if the attributes
>>> + are known to be equal; otherwise return false. */
>>> +
>>> +static bool
>>> +attribute_equal (const_tree attr1, const_tree attr2)
>>> +{
>>> + if (attr1 == attr2)
>>> + return true;
>>> +
>>
>> Shouldn't this compare the TREE_VALUEs?
>>
>> This function is also assuming that the TREE_PURPOSEs name the same
>> attribute. I had figured that we would pull out the TREE_VALUE in the
>> caller, but doing it in here is fine too as long as the function is
>> documented as making that assumption.
>>
>> Jason
>>
>
> I added an note to the documentation of the helper function. Ok by this?
>
> Kai
>
I thought a bit about it and renamed function's name to
attribute_value_equal and adjusted helper functions comment to point
out that just value identity is checked by it. Previous variant was a
bit weak.
Kai
Index: gcc/gcc/c-typeck.c
===================================================================
--- gcc.orig/gcc/c-typeck.c 2011-03-24 08:23:42.441173500 +0100
+++ gcc/gcc/c-typeck.c 2011-03-24 09:24:53.445892300 +0100
@@ -1079,7 +1079,7 @@ comptypes_internal (const_tree type1, co
return 1;
/* 1 if no need for warning yet, 2 if warning cause has been seen. */
- if (!(attrval = targetm.comp_type_attributes (t1, t2)))
+ if (!(attrval = comp_type_attributes (t1, t2)))
return 0;
/* 1 if no need for warning yet, 2 if warning cause has been seen. */
Index: gcc/gcc/cp/decl.c
===================================================================
--- gcc.orig/gcc/cp/decl.c 2011-03-24 08:23:42.443173500 +0100
+++ gcc/gcc/cp/decl.c 2011-03-24 09:24:53.573408500 +0100
@@ -1012,8 +1012,8 @@ decls_match (tree newdecl, tree olddecl)
types_match =
compparms (p1, p2)
&& (TYPE_ATTRIBUTES (TREE_TYPE (newdecl)) == NULL_TREE
- || targetm.comp_type_attributes (TREE_TYPE (newdecl),
- TREE_TYPE (olddecl)) != 0);
+ || comp_type_attributes (TREE_TYPE (newdecl),
+ TREE_TYPE (olddecl)) != 0);
}
else
types_match = 0;
Index: gcc/gcc/cp/search.c
===================================================================
--- gcc.orig/gcc/cp/search.c 2011-03-24 08:23:42.444173500 +0100
+++ gcc/gcc/cp/search.c 2011-03-24 09:24:53.645417600 +0100
@@ -1897,7 +1897,7 @@ check_final_overrider (tree overrider, t
}
/* Check for conflicting type attributes. */
- if (!targetm.comp_type_attributes (over_type, base_type))
+ if (!comp_type_attributes (over_type, base_type))
{
error ("conflicting type attributes specified for %q+#D", overrider);
error (" overriding %q+#D", basefn);
Index: gcc/gcc/cp/typeck.c
===================================================================
--- gcc.orig/gcc/cp/typeck.c 2011-03-24 08:23:42.495173500 +0100
+++ gcc/gcc/cp/typeck.c 2011-03-24 09:24:53.697424200 +0100
@@ -1338,7 +1338,7 @@ structural_comptypes (tree t1, tree t2,
/* If we get here, we know that from a target independent POV the
types are the same. Make sure the target attributes are also
the same. */
- return targetm.comp_type_attributes (t1, t2);
+ return comp_type_attributes (t1, t2);
}
/* Return true if T1 and T2 are related as allowed by STRICT. STRICT
Index: gcc/gcc/gimple.c
===================================================================
--- gcc.orig/gcc/gimple.c 2011-03-24 08:23:42.496173500 +0100
+++ gcc/gcc/gimple.c 2011-03-24 09:24:53.793936500 +0100
@@ -3615,7 +3615,7 @@ gimple_types_compatible_p_1 (tree t1, tr
state, sccstack, sccstate, sccstate_obstack))
goto different_types;
- if (!targetm.comp_type_attributes (t1, t2))
+ if (!comp_type_attributes (t1, t2))
goto different_types;
if (TYPE_ARG_TYPES (t1) == TYPE_ARG_TYPES (t2))
Index: gcc/gcc/tree-ssa.c
===================================================================
--- gcc.orig/gcc/tree-ssa.c 2011-03-24 08:23:42.498173500 +0100
+++ gcc/gcc/tree-ssa.c 2011-03-24 09:24:53.831441200 +0100
@@ -1438,7 +1438,7 @@ useless_type_conversion_p (tree outer_ty
/* Defer to the target if necessary. */
if (TYPE_ATTRIBUTES (inner_type) || TYPE_ATTRIBUTES (outer_type))
- return targetm.comp_type_attributes (outer_type, inner_type) != 0;
+ return comp_type_attributes (outer_type, inner_type) != 0;
return true;
}
Index: gcc/gcc/tree.c
===================================================================
--- gcc.orig/gcc/tree.c 2011-03-24 08:23:42.499173500 +0100
+++ gcc/gcc/tree.c 2011-03-24 20:42:37.699096700 +0100
@@ -4283,7 +4283,7 @@ build_type_attribute_qual_variant (tree
its canonical type, we will need to use structural equality
checks for this type. */
if (TYPE_STRUCTURAL_EQUALITY_P (ttype)
- || !targetm.comp_type_attributes (ntype, ttype))
+ || !comp_type_attributes (ntype, ttype))
SET_TYPE_STRUCTURAL_EQUALITY (ntype);
else if (TYPE_CANONICAL (ntype) == ntype)
TYPE_CANONICAL (ntype) = TYPE_CANONICAL (ttype);
@@ -4296,6 +4296,75 @@ build_type_attribute_qual_variant (tree
return ttype;
}
+/* Compare two attributes for their value identity. Return true if the
attribute
+ values are known to be equal; otherwise return false.
+*/
+
+static bool
+attribute_value_equal (const_tree attr1, const_tree attr2)
+{
+ if (attr1 == attr2)
+ return true;
+
+ if (TREE_VALUE (attr1) != NULL_TREE
+ && TREE_CODE (TREE_VALUE (attr1)) == TREE_LIST
+ && TREE_VALUE (attr2) != NULL
+ && TREE_CODE (TREE_VALUE (attr2)) == TREE_LIST)
+ return (simple_cst_list_equal (TREE_VALUE (attr1),
+ TREE_VALUE (attr2)) == 1);
+
+ return (simple_cst_equal (TREE_VALUE (attr1), TREE_VALUE (attr2)) == 1);
+}
+
+/* Return 0 if the attributes for two types are incompatible, 1 if they
+ are compatible, and 2 if they are nearly compatible (which causes a
+ warning to be generated). */
+int
+comp_type_attributes (const_tree type1, const_tree type2)
+{
+ const_tree a1 = TYPE_ATTRIBUTES (type1);
+ const_tree a2 = TYPE_ATTRIBUTES (type2);
+ const_tree a;
+
+ if (a1 == a2)
+ return 1;
+ for (a = a1; a != NULL_TREE; a = TREE_CHAIN (a))
+ {
+ const struct attribute_spec *as;
+ const_tree attr;
+
+ as = lookup_attribute_spec (TREE_PURPOSE (a));
+ if (!as || as->affects_type_identity == false)
+ continue;
+
+ attr = lookup_attribute (as->name, CONST_CAST_TREE (a2));
+ if (!attr || !attribute_value_equal (a, attr))
+ break;
+ }
+ if (!a)
+ {
+ for (a = a2; a != NULL_TREE; a = TREE_CHAIN (a))
+ {
+ const struct attribute_spec *as;
+
+ as = lookup_attribute_spec (TREE_PURPOSE (a));
+ if (!as || as->affects_type_identity == false)
+ continue;
+
+ if (!lookup_attribute (as->name, CONST_CAST_TREE (a1)))
+ break;
+ /* We don't need to compare trees again, as we did this
+ already in first loop. */
+ }
+ /* All types - affecting identity - are equal, so
+ there is no need to call target hook for comparison. */
+ if (!a)
+ return 1;
+ }
+ /* As some type combinations - like default calling-convention - might
+ be compatible, we have to call the target hook to get the final result.
*/
+ return targetm.comp_type_attributes (type1, type2);
+}
/* Return a type like TTYPE except that its TYPE_ATTRIBUTE
is ATTRIBUTE.
@@ -5296,23 +5365,10 @@ merge_attributes (tree a1, tree a2)
tree a;
for (a = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
attributes);
- a != NULL_TREE;
+ a != NULL_TREE && !attribute_value_equal (a, a2);
a = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
TREE_CHAIN (a)))
- {
- if (TREE_VALUE (a) != NULL
- && TREE_CODE (TREE_VALUE (a)) == TREE_LIST
- && TREE_VALUE (a2) != NULL
- && TREE_CODE (TREE_VALUE (a2)) == TREE_LIST)
- {
- if (simple_cst_list_equal (TREE_VALUE (a),
- TREE_VALUE (a2)) == 1)
- break;
- }
- else if (simple_cst_equal (TREE_VALUE (a),
- TREE_VALUE (a2)) == 1)
- break;
- }
+ ;
if (a == NULL_TREE)
{
a1 = copy_node (a2);
@@ -6250,24 +6306,12 @@ attribute_list_contained (const_tree l1,
const_tree. */
for (attr = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)),
CONST_CAST_TREE(l1));
- attr != NULL_TREE;
+ attr != NULL_TREE && !attribute_value_equal (t2, attr);
attr = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)),
TREE_CHAIN (attr)))
- {
- if (TREE_VALUE (t2) != NULL
- && TREE_CODE (TREE_VALUE (t2)) == TREE_LIST
- && TREE_VALUE (attr) != NULL
- && TREE_CODE (TREE_VALUE (attr)) == TREE_LIST)
- {
- if (simple_cst_list_equal (TREE_VALUE (t2),
- TREE_VALUE (attr)) == 1)
- break;
- }
- else if (simple_cst_equal (TREE_VALUE (t2), TREE_VALUE (attr)) == 1)
- break;
- }
+ ;
- if (attr == 0)
+ if (attr == NULL_TREE)
return 0;
}
Index: gcc/gcc/tree.h
===================================================================
--- gcc.orig/gcc/tree.h 2011-03-24 08:23:42.619173500 +0100
+++ gcc/gcc/tree.h 2011-03-24 09:24:54.041968000 +0100
@@ -4286,6 +4286,11 @@ extern tree build_type_attribute_variant
extern tree build_decl_attribute_variant (tree, tree);
extern tree build_type_attribute_qual_variant (tree, tree, int);
+/* Return 0 if the attributes for two types are incompatible, 1 if they
+ are compatible, and 2 if they are nearly compatible (which causes a
+ warning to be generated). */
+extern int comp_type_attributes (const_tree, const_tree);
+
/* Structure describing an attribute and a function to handle it. */
struct attribute_spec
{
