Hi!
This patch prevents init values of STRING_CST and braced
array initializers to reach the middle-end with incomplete
type.
This will allow further simplifications in the middle-end,
and address existing issues with STRING_CST in a correct
way.
Bootstrapped and reg-tested on x86_64-pc-linux-gnu.
Is it OK for trunk?
Thanks
Bernd.
gcc:
2018-08-24 Bernd Edlinger <bernd.edlin...@hotmail.de>
* varasm.c (output_constructor_regular_field): Check TYPE_SIZE_UNIT of
the init value.
c-family:
2018-08-24 Bernd Edlinger <bernd.edlin...@hotmail.de>
* c-common.c (complete_flexible_array_elts): New helper function.
* c-common.h (complete_flexible_array_elts): Declare.
c:
2018-08-24 Bernd Edlinger <bernd.edlin...@hotmail.de>
* c-decl.c (finish_decl): Call complete_flexible_array_elts.
cp:
2018-08-24 Bernd Edlinger <bernd.edlin...@hotmail.de>
* decl.c (check_initializer): Call complete_flexible_array_elts.
diff -Npur gcc/c/c-decl.c gcc/c/c-decl.c
--- gcc/c/c-decl.c 2018-08-21 08:17:41.000000000 +0200
+++ gcc/c/c-decl.c 2018-08-24 12:06:21.374892294 +0200
@@ -5035,6 +5035,8 @@ finish_decl (tree decl, location_t init_
if (init && TREE_CODE (init) == CONSTRUCTOR)
add_flexible_array_elts_to_size (decl, init);
+ complete_flexible_array_elts (DECL_INITIAL (decl));
+
if (DECL_SIZE (decl) == NULL_TREE && TREE_TYPE (decl) != error_mark_node
&& COMPLETE_TYPE_P (TREE_TYPE (decl)))
layout_decl (decl, 0);
diff -Npur gcc/c-family/c-common.c gcc/c-family/c-common.c
--- gcc/c-family/c-common.c 2018-08-17 05:02:11.000000000 +0200
+++ gcc/c-family/c-common.c 2018-08-24 12:45:56.559011703 +0200
@@ -6427,6 +6427,28 @@ complete_array_type (tree *ptype, tree i
return failure;
}
+/* INIT is an constructor of a structure with a flexible array member.
+ Complete the flexible array member with a domain based on it's value. */
+void
+complete_flexible_array_elts (tree init)
+{
+ tree elt, type;
+
+ if (init == NULL_TREE || TREE_CODE (init) != CONSTRUCTOR)
+ return;
+
+ if (vec_safe_is_empty (CONSTRUCTOR_ELTS (init)))
+ return;
+
+ elt = CONSTRUCTOR_ELTS (init)->last ().value;
+ type = TREE_TYPE (elt);
+ if (TREE_CODE (type) == ARRAY_TYPE
+ && TYPE_SIZE (type) == NULL_TREE)
+ complete_array_type (&TREE_TYPE (elt), elt, false);
+ else
+ complete_flexible_array_elts (elt);
+}
+
/* Like c_mark_addressable but don't check register qualifier. */
void
c_common_mark_addressable_vec (tree t)
diff -Npur gcc/c-family/c-common.h gcc/c-family/c-common.h
--- gcc/c-family/c-common.h 2018-08-17 05:02:11.000000000 +0200
+++ gcc/c-family/c-common.h 2018-08-24 12:06:21.375892280 +0200
@@ -1038,6 +1038,7 @@ extern tree fold_offsetof (tree, tree =
tree_code ctx = ERROR_MARK);
extern int complete_array_type (tree *, tree, bool);
+extern void complete_flexible_array_elts (tree);
extern tree builtin_type_for_size (int, bool);
diff -Npur gcc/cp/decl.c gcc/cp/decl.c
--- gcc/cp/decl.c 2018-08-22 22:35:38.000000000 +0200
+++ gcc/cp/decl.c 2018-08-24 12:06:21.377892252 +0200
@@ -6528,6 +6528,8 @@ check_initializer (tree decl, tree init,
init_code = store_init_value (decl, init, cleanups, flags);
+ complete_flexible_array_elts (DECL_INITIAL (decl));
+
if (pedantic && TREE_CODE (type) == ARRAY_TYPE
&& DECL_INITIAL (decl)
&& TREE_CODE (DECL_INITIAL (decl)) == STRING_CST
diff -Npur gcc/varasm.c gcc/varasm.c
--- gcc/varasm.c 2018-08-16 17:28:11.000000000 +0200
+++ gcc/varasm.c 2018-08-24 12:06:21.378892238 +0200
@@ -5161,6 +5161,8 @@ output_constructor_regular_field (oc_loc
on the chain is a TYPE_DECL of the enclosing struct. */
const_tree next = DECL_CHAIN (local->field);
gcc_assert (!fieldsize || !next || TREE_CODE (next) != FIELD_DECL);
+ tree size = TYPE_SIZE_UNIT (TREE_TYPE (local->val));
+ gcc_checking_assert (compare_tree_int (size, fieldsize) == 0);
}
else
fieldsize = tree_to_uhwi (DECL_SIZE_UNIT (local->field));
