Hi,
this is a regression present on the mainline and 9 branch: the compiler gives
an ICE for the attached Ada testcase on the following assertion:
if (DECL_P (ref))
{
/* We shouldn't have true variables here. */
gcc_assert (TREE_READONLY (ref));
subst = ref;
}
in self_referential_size because the size function machinery is invoked again
by the *free_lang_data pass, more precisely from fld_process_array_type:
if (!existed)
{
array
= build_array_type_1 (t2, TYPE_DOMAIN (t), TYPE_TYPELESS_STORAGE (t),
false, false);
TYPE_CANONICAL (array) = TYPE_CANONICAL (t);
if (!fld->pset.add (array))
add_tree_to_fld_list (array, fld);
}
through the call to build_array_type_1, and more precisely through the
recursive call made for computing TYPE_CANONICAL:
if (TYPE_CANONICAL (t) == t)
{
if (TYPE_STRUCTURAL_EQUALITY_P (elt_type)
|| (index_type && TYPE_STRUCTURAL_EQUALITY_P (index_type))
|| in_lto_p)
SET_TYPE_STRUCTURAL_EQUALITY (t);
else if (TYPE_CANONICAL (elt_type) != elt_type
|| (index_type && TYPE_CANONICAL (index_type) != index_type))
TYPE_CANONICAL (t)
= build_array_type_1 (TYPE_CANONICAL (elt_type),
index_type
? TYPE_CANONICAL (index_type) : NULL_TREE,
typeless_storage, shared, set_canonical);
}
That's a bit surprising because t2 is an incomplete type and we have these
lines in build_array_type_1 just before:
/* If the element type is incomplete at this point we get marked for
structural equality. Do not record these types in the canonical
type hashtable. */
if (TYPE_STRUCTURAL_EQUALITY_P (t))
return t;
so the computation of TYPE_CANONICAL should be skipped. But it turns out that
these lines from 2009 are obsolete because layout_type no longer forces the
TYPE_STRUCTURAL_EQUALITY_P on the array when the element type is incomplete.
Since fld_process_array_type overwrites TYPE_CANONICAL just after the call to
build_array_type_1, there is no point for the latter in computing it so the
proposed fix is to add a new SET_CANONICAL parameter to build_array_type_1.
Tested on x86_64-suse-linux, OK for mainline and 9 branch?
2019-12-09 Eric Botcazou <ebotca...@adacore.com>
* tree.c (build_array_type_1): Add SET_CANONICAL parameter and compute
TYPE_CANONICAL from the element type only if it is set. Remove obsolete
lines and adjust recursive call.
(fld_process_array_type): Adjust call to build_array_type_1.
(build_array_type): Likewise.
(build_nonshared_array_type): Likewise.
2019-12-09 Eric Botcazou <ebotca...@adacore.com>
* gnat.dg/lto23.adb: New test.
--
Eric BotcazouIndex: tree.c
===================================================================
--- tree.c (revision 278938)
+++ tree.c (working copy)
@@ -266,7 +266,7 @@ static void print_type_hash_statistics (
static void print_debug_expr_statistics (void);
static void print_value_expr_statistics (void);
-static tree build_array_type_1 (tree, tree, bool, bool);
+static tree build_array_type_1 (tree, tree, bool, bool, bool);
tree global_trees[TI_MAX];
tree integer_types[itk_none];
@@ -5303,8 +5303,9 @@ fld_process_array_type (tree t, tree t2,
= map->get_or_insert (t, &existed);
if (!existed)
{
- array = build_array_type_1 (t2, TYPE_DOMAIN (t),
- TYPE_TYPELESS_STORAGE (t), false);
+ array
+ = build_array_type_1 (t2, TYPE_DOMAIN (t), TYPE_TYPELESS_STORAGE (t),
+ false, false);
TYPE_CANONICAL (array) = TYPE_CANONICAL (t);
if (!fld->pset.add (array))
add_tree_to_fld_list (array, fld);
@@ -8155,11 +8156,12 @@ subrange_type_for_debug_p (const_tree ty
/* Construct, lay out and return the type of arrays of elements with ELT_TYPE
and number of elements specified by the range of values of INDEX_TYPE.
If TYPELESS_STORAGE is true, TYPE_TYPELESS_STORAGE flag is set on the type.
- If SHARED is true, reuse such a type that has already been constructed. */
+ If SHARED is true, reuse such a type that has already been constructed.
+ If SET_CANONICAL is true, compute TYPE_CANONICAL from the element type. */
static tree
build_array_type_1 (tree elt_type, tree index_type, bool typeless_storage,
- bool shared)
+ bool shared, bool set_canonical)
{
tree t;
@@ -8176,19 +8178,13 @@ build_array_type_1 (tree elt_type, tree
TYPE_TYPELESS_STORAGE (t) = typeless_storage;
layout_type (t);
- /* If the element type is incomplete at this point we get marked for
- structural equality. Do not record these types in the canonical
- type hashtable. */
- if (TYPE_STRUCTURAL_EQUALITY_P (t))
- return t;
-
if (shared)
{
hashval_t hash = type_hash_canon_hash (t);
t = type_hash_canon (hash, t);
}
- if (TYPE_CANONICAL (t) == t)
+ if (TYPE_CANONICAL (t) == t && set_canonical)
{
if (TYPE_STRUCTURAL_EQUALITY_P (elt_type)
|| (index_type && TYPE_STRUCTURAL_EQUALITY_P (index_type))
@@ -8200,7 +8196,7 @@ build_array_type_1 (tree elt_type, tree
= build_array_type_1 (TYPE_CANONICAL (elt_type),
index_type
? TYPE_CANONICAL (index_type) : NULL_TREE,
- typeless_storage, shared);
+ typeless_storage, shared, set_canonical);
}
return t;
@@ -8211,7 +8207,8 @@ build_array_type_1 (tree elt_type, tree
tree
build_array_type (tree elt_type, tree index_type, bool typeless_storage)
{
- return build_array_type_1 (elt_type, index_type, typeless_storage, true);
+ return
+ build_array_type_1 (elt_type, index_type, typeless_storage, true, true);
}
/* Wrapper around build_array_type_1 with SHARED set to false. */
@@ -8219,7 +8216,7 @@ build_array_type (tree elt_type, tree in
tree
build_nonshared_array_type (tree elt_type, tree index_type)
{
- return build_array_type_1 (elt_type, index_type, false, false);
+ return build_array_type_1 (elt_type, index_type, false, false, true);
}
/* Return a representation of ELT_TYPE[NELTS], using indices of type
-- { dg-do compile }
-- { dg-options "-flto" { target lto } }
procedure Lto23 (N : Natural) is
type Root is tagged null record;
type Vec is array (Positive range <>) of Root;
type Rec is record
V : Vec (1 .. N);
end record;
type Arr is array (Positive range <>) of Rec;
A : Arr (1 .. 4);
begin
null;
end;
