https://gcc.gnu.org/g:4c5bea7def13613fba166edb23289bab446b0b48
commit r15-948-g4c5bea7def13613fba166edb23289bab446b0b48
Author: Qing Zhao <qing.z...@oracle.com>
Date: Tue May 28 18:39:31 2024 +0000
Add the 6th argument to .ACCESS_WITH_SIZE
to carry the TYPE of the flexible array.
Such information is needed during tree-object-size.cc.
We cannot use the result type or the type of the 1st argument
of the routine .ACCESS_WITH_SIZE to decide the element type
of the original array due to possible type casting in the
source code.
gcc/c/ChangeLog:
* c-typeck.cc (build_access_with_size_for_counted_by): Add the 6th
argument to .ACCESS_WITH_SIZE.
gcc/ChangeLog:
* tree-object-size.cc (access_with_size_object_size): Use the type
of the 6th argument for the type of the element.
* internal-fn.cc (expand_ACCESS_WITH_SIZE): Update the comment with
the 6th argument.
gcc/testsuite/ChangeLog:
* gcc.dg/flex-array-counted-by-6.c: New test.
Diff:
---
gcc/c/c-typeck.cc | 11 ++++--
gcc/internal-fn.cc | 2 ++
gcc/testsuite/gcc.dg/flex-array-counted-by-6.c | 46 ++++++++++++++++++++++++++
gcc/tree-object-size.cc | 16 +++++----
4 files changed, 66 insertions(+), 9 deletions(-)
diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 268c3ddbe14..a0e7dbe1b48 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -2714,7 +2714,8 @@ build_counted_by_ref (tree datum, tree subdatum, tree
*counted_by_type)
to:
- (*.ACCESS_WITH_SIZE (REF, COUNTED_BY_REF, 1, (TYPE_OF_SIZE)0, -1))
+ (*.ACCESS_WITH_SIZE (REF, COUNTED_BY_REF, 1, (TYPE_OF_SIZE)0, -1,
+ (TYPE_OF_ARRAY *)0))
NOTE: The return type of this function is the POINTER type pointing
to the original flexible array type.
@@ -2726,6 +2727,9 @@ build_counted_by_ref (tree datum, tree subdatum, tree
*counted_by_type)
The 4th argument of the call is a constant 0 with the TYPE of the
object pointed by COUNTED_BY_REF.
+ The 6th argument of the call is a constant 0 with the pointer TYPE
+ to the original flexible array type.
+
*/
static tree
build_access_with_size_for_counted_by (location_t loc, tree ref,
@@ -2738,12 +2742,13 @@ build_access_with_size_for_counted_by (location_t loc,
tree ref,
tree call
= build_call_expr_internal_loc (loc, IFN_ACCESS_WITH_SIZE,
- result_type, 5,
+ result_type, 6,
array_to_pointer_conversion (loc, ref),
counted_by_ref,
build_int_cst (integer_type_node, 1),
build_int_cst (counted_by_type, 0),
- build_int_cst (integer_type_node, -1));
+ build_int_cst (integer_type_node, -1),
+ build_int_cst (result_type, 0));
/* Wrap the call with an INDIRECT_REF with the flexible array type. */
call = build1 (INDIRECT_REF, TREE_TYPE (ref), call);
SET_EXPR_LOCATION (call, loc);
diff --git a/gcc/internal-fn.cc b/gcc/internal-fn.cc
index eb2c4cd5904..0d27f17b283 100644
--- a/gcc/internal-fn.cc
+++ b/gcc/internal-fn.cc
@@ -3456,6 +3456,8 @@ expand_DEFERRED_INIT (internal_fn, gcall *stmt)
1: read_only
2: write_only
3: read_write
+ 6th argument: A constant 0 with the pointer TYPE to the original flexible
+ array type.
Both the return type and the type of the first argument of this
function have been converted from the incomplete array type to
diff --git a/gcc/testsuite/gcc.dg/flex-array-counted-by-6.c
b/gcc/testsuite/gcc.dg/flex-array-counted-by-6.c
new file mode 100644
index 00000000000..65fa01443d9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/flex-array-counted-by-6.c
@@ -0,0 +1,46 @@
+/* Test the attribute counted_by and its usage in
+ * __builtin_dynamic_object_size: when the type of the flexible array member
+ * is casting to another type. */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#include "builtin-object-size-common.h"
+
+typedef unsigned short u16;
+
+struct info {
+ u16 data_len;
+ char data[] __attribute__((counted_by(data_len)));
+};
+
+struct foo {
+ int a;
+ int b;
+};
+
+static __attribute__((__noinline__))
+struct info *setup ()
+{
+ struct info *p;
+ size_t bytes = 3 * sizeof(struct foo);
+
+ p = (struct info *)malloc (sizeof (struct info) + bytes);
+ p->data_len = bytes;
+
+ return p;
+}
+
+static void
+__attribute__((__noinline__)) report (struct info *p)
+{
+ struct foo *bar = (struct foo *)p->data;
+ EXPECT(__builtin_dynamic_object_size((char *)(bar + 1), 1), 16);
+ EXPECT(__builtin_dynamic_object_size((char *)(bar + 2), 1), 8);
+}
+
+int main(int argc, char *argv[])
+{
+ struct info *p = setup();
+ report(p);
+ return 0;
+}
diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
index 8de264d1dee..4c1fa9b555f 100644
--- a/gcc/tree-object-size.cc
+++ b/gcc/tree-object-size.cc
@@ -762,9 +762,11 @@ addr_object_size (struct object_size_info *osi, const_tree
ptr,
1: the number of the elements of the object type;
4th argument TYPE_OF_SIZE: A constant 0 with its TYPE being the same as the
TYPE
of the object referenced by REF_TO_SIZE
+ 6th argument: A constant 0 with the pointer TYPE to the original flexible
+ array type.
- The size of the element can be retrived from the result type of the call,
- which is the pointer to the array type. */
+ The size of the element can be retrived from the TYPE of the 6th argument
+ of the call, which is the pointer to the array type. */
static tree
access_with_size_object_size (const gcall *call, int object_size_type)
{
@@ -773,10 +775,12 @@ access_with_size_object_size (const gcall *call, int
object_size_type)
return size_unknown (object_size_type);
gcc_assert (gimple_call_internal_p (call, IFN_ACCESS_WITH_SIZE));
- /* Result type is a pointer type to the original flexible array type. */
- tree result_type = gimple_call_return_type (call);
- gcc_assert (POINTER_TYPE_P (result_type));
- tree element_size = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (result_type)));
+ /* The type of the 6th argument type is the pointer TYPE to the original
+ flexible array type. */
+ tree pointer_to_array_type = TREE_TYPE (gimple_call_arg (call, 5));
+ gcc_assert (POINTER_TYPE_P (pointer_to_array_type));
+ tree element_type = TREE_TYPE (TREE_TYPE (pointer_to_array_type));
+ tree element_size = TYPE_SIZE_UNIT (element_type);
tree ref_to_size = gimple_call_arg (call, 1);
unsigned int class_of_size = TREE_INT_CST_LOW (gimple_call_arg (call, 2));
tree type = TREE_TYPE (gimple_call_arg (call, 3));
