Fix verify_type ICE on TYPE_METHOS
Jan Hubicka
hubicka@ucw.cz
Mon May 11 11:39:00 GMT 2015
Jason,
this patch is trying to fix the following verify_type_ice that check
that TYPE_METHODS is same for main variant and all its complete variants.
- /* FIXME: this check triggers during libstdc++ build that is a bug.
- It affects non-LTO debug output only, because free_lang_data clears
- this anyway. */
- if (RECORD_OR_UNION_TYPE_P (t) && COMPLETE_TYPE_P (t) && 0
- && TYPE_METHODS (t) != TYPE_METHODS (tv))
I tried to go in a way of making TYPE_METHODS to be defined only on main vairants
as it seems impractical to update variants each time we change TYPE_METHODS.
While doing so, I noticed that lazily_declare_fn sometimes adds new method
to variant only (that is probably source of ICE as fixup_type_variants copies the
TYPE_METHODS).
The attach patch however removes the copying and verifies that TYPE_MEHTODS is
NULL at all variants. It also updates middle-end uses to always check for main variant.
Bootstrapped/regtested ppc64-linux, does this seem to make sense?
I also noticed that TYPE_METHODS != NULL matters in some cases: it makes function.c
to drop register keyword and it makes us to speak of class instead of struct in
diagnostics, so I changed free_lang_data to zap the list to error_mark_node instead
of NULL (in past I tried to stream it for ODR warnings and I remember it added
measurable extra overhead that I considered too large for mainline).
Honza
* class.c (fixup_type_variants): Do not copy TYPE_METHODS
(one_inheriting_sig): Assert tat we always set TYPE_METHODS of main variant.
* semantics.c (finish_member_declaration): Likewise.
* method.c (lazily_declare_fn): Allways add method to main variant list.
* dwarf2out.c (gen_member_die): Sanity check that we access TYPE_MAIN_VARIANT
for TYPE_METHODS.
* function.c (use_register_for_decl): Look for TYPE_MAIN_VARIANT when checking
TYPE_METHODS.
* tree.c (free_lang_data_in_type): See TYPE_METHODS to error_mark_node
if non-null.
(build_distinct_type_copy): Clear TYPE_METHODS.
(verify_type_variant): Verify that TYPE_METHODS is NULL for variants.
(verify_type): Allow TYPE_METHODS to be error_mark_node.
* tree.def: Update docs of YTPE_STUB_DECL and TYPE_METHODS.
Index: cp/class.c
===================================================================
--- cp/class.c (revision 222991)
+++ cp/class.c (working copy)
@@ -1972,7 +1972,6 @@ fixup_type_variants (tree t)
/* Copy whatever these are holding today. */
TYPE_VFIELD (variants) = TYPE_VFIELD (t);
- TYPE_METHODS (variants) = TYPE_METHODS (t);
TYPE_FIELDS (variants) = TYPE_FIELDS (t);
}
}
@@ -3238,6 +3237,7 @@ one_inheriting_sig (tree t, tree ctor, t
parmlist = tree_cons (NULL_TREE, parms[i], parmlist);
tree fn = implicitly_declare_fn (sfk_inheriting_constructor,
t, false, ctor, parmlist);
+ gcc_assert (TYPE_MAIN_VARIANT (t) == t);
if (add_method (t, fn, NULL_TREE))
{
DECL_CHAIN (fn) = TYPE_METHODS (t);
Index: cp/method.c
===================================================================
--- cp/method.c (revision 222991)
+++ cp/method.c (working copy)
@@ -2189,11 +2189,11 @@ lazily_declare_fn (special_function_kind
&& DECL_VIRTUAL_P (fn))
/* The ABI requires that a virtual destructor go at the end of the
vtable. */
- TYPE_METHODS (type) = chainon (TYPE_METHODS (type), fn);
+ TYPE_METHODS (type) = chainon (TYPE_METHODS (TYPE_MAIN_VARIANT (type)), fn);
else
{
- DECL_CHAIN (fn) = TYPE_METHODS (type);
- TYPE_METHODS (type) = fn;
+ DECL_CHAIN (fn) = TYPE_METHODS (TYPE_MAIN_VARIANT (type));
+ TYPE_METHODS (TYPE_MAIN_VARIANT (type)) = fn;
}
maybe_add_class_template_decl_list (type, fn, /*friend_p=*/0);
if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)
Index: cp/semantics.c
===================================================================
--- cp/semantics.c (revision 222991)
+++ cp/semantics.c (working copy)
@@ -2913,6 +2913,7 @@ finish_member_declaration (tree decl)
CLASSTYPE_METHOD_VEC. */
if (add_method (current_class_type, decl, NULL_TREE))
{
+ gcc_assert (TYPE_MAIN_VARIANT (current_class_type) == current_class_type);
DECL_CHAIN (decl) = TYPE_METHODS (current_class_type);
TYPE_METHODS (current_class_type) = decl;
Index: dwarf2out.c
===================================================================
--- dwarf2out.c (revision 222991)
+++ dwarf2out.c (working copy)
@@ -19945,6 +19945,8 @@ gen_member_die (tree type, dw_die_ref co
gen_decl_die (member, NULL, context_die);
}
+ /* We do not keep type methods in type variants. */
+ gcc_assert (TYPE_MAIN_VARIANT (type) == type);
/* Now output info about the function members (if any). */
for (member = TYPE_METHODS (type); member; member = DECL_CHAIN (member))
{
Index: function.c
===================================================================
--- function.c (revision 222991)
+++ function.c (working copy)
@@ -2170,7 +2170,7 @@ use_register_for_decl (const_tree decl)
/* When not optimizing, disregard register keyword for variables with
types containing methods, otherwise the methods won't be callable
from the debugger. */
- if (TYPE_METHODS (TREE_TYPE (decl)))
+ if (TYPE_METHODS (TYPE_MAIN_VARIANT (TREE_TYPE (decl))))
return false;
break;
default:
Index: tree.c
===================================================================
--- tree.c (revision 222991)
+++ tree.c (working copy)
@@ -5100,7 +5100,13 @@ free_lang_data_in_type (tree type)
if (TYPE_VFIELD (type) && TREE_CODE (TYPE_VFIELD (type)) != FIELD_DECL)
TYPE_VFIELD (type) = NULL_TREE;
- TYPE_METHODS (type) = NULL_TREE;
+ /* Remove TYPE_METHODS list. While it would be nice to keep it
+ to enable ODR warnings about different method lists, doing so
+ seems to impractically increase size of LTO data streamed.
+ Keep the information if TYPE_METHODS was non-NULL. This is used
+ by function.c and pretty printers. */
+ if (TYPE_METHODS (type))
+ TYPE_METHODS (type) = error_mark_node;
if (TYPE_BINFO (type))
{
free_lang_data_in_binfo (TYPE_BINFO (type));
@@ -6574,6 +6580,12 @@ build_distinct_type_copy (tree type)
TYPE_MAIN_VARIANT (t) = t;
TYPE_NEXT_VARIANT (t) = 0;
+ /* We do not record methods in type copies nor variants
+ so we do not need to keep them up to date when new method
+ is inserted. */
+ if (RECORD_OR_UNION_TYPE_P (t))
+ TYPE_METHODS (t) = NULL_TREE;
+
/* Note that it is now possible for TYPE_MIN_VALUE to be a value
whose TREE_TYPE is not t. This can also happen in the Ada
frontend when using subtypes. */
@@ -12528,13 +12540,9 @@ verify_type_variant (const_tree t, tree
debug_tree (tv);
return false;
}
- /* FIXME: this check triggers during libstdc++ build that is a bug.
- It affects non-LTO debug output only, because free_lang_data clears
- this anyway. */
- if (RECORD_OR_UNION_TYPE_P (t) && COMPLETE_TYPE_P (t) && 0
- && TYPE_METHODS (t) != TYPE_METHODS (tv))
+ if (RECORD_OR_UNION_TYPE_P (t) && TYPE_METHODS (t))
{
- error ("type variant has different TYPE_METHODS");
+ error ("type variant has TYPE_METHODS");
debug_tree (tv);
return false;
}
@@ -12749,9 +12757,10 @@ verify_type (const_tree t)
if (RECORD_OR_UNION_TYPE_P (t))
{
if (TYPE_METHODS (t) && TREE_CODE (TYPE_METHODS (t)) != FUNCTION_DECL
- && TREE_CODE (TYPE_METHODS (t)) != TEMPLATE_DECL)
+ && TREE_CODE (TYPE_METHODS (t)) != TEMPLATE_DECL
+ && TYPE_METHODS (t) != error_mark_node)
{
- error ("TYPE_METHODS is not FUNCTION_DECL nor TEMPLATE_DECL");
+ error ("TYPE_METHODS is not FUNCTION_DECL, TEMPLATE_DECL nor error_mark_node");
debug_tree (TYPE_METHODS (t));
error_found = true;
}
Index: tree.def
===================================================================
--- tree.def (revision 222991)
+++ tree.def (working copy)
@@ -110,9 +110,12 @@ DEFTREECODE (BLOCK, "block", tcc_excepti
particular, since any type which is of some type category (e.g.
an array type or a function type) which cannot either have a name
itself or have named members doesn't really have a "scope" per se.
- The TREE_CHAIN field is used as a forward-references to names for
+ The TYPE_STUB_DECL field is used as a forward-references to names for
ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes;
- see below. */
+ see below.
+ The TYPE_METHODS points to list of all methods associated with the type.
+ It is non-NULL only at main variant of the type and after free_lang_data
+ it may be set to error_mark_node instead of actual list to save memory. */
/* The ordering of the following codes is optimized for the checking
macros in tree.h. Changing the order will degrade the speed of the
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