* [GCC13][Patch][V2][2/2]Add a new option -fstrict-flex-array[=n] and attribute strict_flex_array(n) and use it in PR101836
@ 2022-07-19 14:11 Qing Zhao
2022-07-28 7:28 ` Richard Biener
2022-08-02 15:30 ` Kees Cook
0 siblings, 2 replies; 7+ messages in thread
From: Qing Zhao @ 2022-07-19 14:11 UTC (permalink / raw)
To: gcc-patches Paul A Clarke via
Cc: jakub Jelinek, richard Biener, martin Sebor, kees Cook, joseph
From a09f39ded462611286a44d9e8273de8342673ba2 Mon Sep 17 00:00:00 2001
From: Qing Zhao <qing.zhao@oracle.com>
Date: Mon, 18 Jul 2022 18:12:26 +0000
Subject: [PATCH 2/2] Use new flag DECL_NOT_FLEXARRAY in __builtin_object_size
[PR101836]
Use new flag DECL_NOT_FLEXARRAY to determine whether the trailing array
of a structure is flexible array member in __builtin_object_size.
gcc/ChangeLog:
PR tree-optimization/101836
* tree-object-size.cc (addr_object_size): Use array_at_struct_end_p
and DECL_NOT_FLEXARRAY to determine a flexible array member reference.
gcc/testsuite/ChangeLog:
PR tree-optimization/101836
* gcc.dg/pr101836.c: New test.
* gcc.dg/pr101836_1.c: New test.
* gcc.dg/pr101836_2.c: New test.
* gcc.dg/pr101836_3.c: New test.
* gcc.dg/pr101836_4.c: New test.
* gcc.dg/pr101836_5.c: New test.
* gcc.dg/strict-flex-array-2.c: New test.
* gcc.dg/strict-flex-array-3.c: New test.
---
gcc/testsuite/gcc.dg/pr101836.c | 60 ++++++++++++++++++++++
gcc/testsuite/gcc.dg/pr101836_1.c | 60 ++++++++++++++++++++++
gcc/testsuite/gcc.dg/pr101836_2.c | 60 ++++++++++++++++++++++
gcc/testsuite/gcc.dg/pr101836_3.c | 60 ++++++++++++++++++++++
gcc/testsuite/gcc.dg/pr101836_4.c | 60 ++++++++++++++++++++++
gcc/testsuite/gcc.dg/pr101836_5.c | 60 ++++++++++++++++++++++
gcc/testsuite/gcc.dg/strict-flex-array-2.c | 60 ++++++++++++++++++++++
gcc/testsuite/gcc.dg/strict-flex-array-3.c | 60 ++++++++++++++++++++++
gcc/tree-object-size.cc | 18 +++----
9 files changed, 489 insertions(+), 9 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/pr101836.c
create mode 100644 gcc/testsuite/gcc.dg/pr101836_1.c
create mode 100644 gcc/testsuite/gcc.dg/pr101836_2.c
create mode 100644 gcc/testsuite/gcc.dg/pr101836_3.c
create mode 100644 gcc/testsuite/gcc.dg/pr101836_4.c
create mode 100644 gcc/testsuite/gcc.dg/pr101836_5.c
create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-2.c
create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-3.c
diff --git a/gcc/testsuite/gcc.dg/pr101836.c b/gcc/testsuite/gcc.dg/pr101836.c
new file mode 100644
index 00000000000..e5b4e5160a4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr101836.c
@@ -0,0 +1,60 @@
+/* -fstrict-flex-array is aliased with -ftrict-flex-array=3, which is the
+ strictest, only [] is treated as flexible array. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-array" } */
+
+#include <stdio.h>
+
+#define expect(p, _v) do { \
+ size_t v = _v; \
+ if (p == v) \
+ printf("ok: %s == %zd\n", #p, p); \
+ else \
+ { \
+ printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
+ __builtin_abort (); \
+ } \
+} while (0);
+
+struct trailing_array_1 {
+ int a;
+ int b;
+ int c[4];
+};
+
+struct trailing_array_2 {
+ int a;
+ int b;
+ int c[1];
+};
+
+struct trailing_array_3 {
+ int a;
+ int b;
+ int c[0];
+};
+struct trailing_array_4 {
+ int a;
+ int b;
+ int c[];
+};
+
+void __attribute__((__noinline__)) stuff(
+ struct trailing_array_1 *normal,
+ struct trailing_array_2 *trailing_1,
+ struct trailing_array_3 *trailing_0,
+ struct trailing_array_4 *trailing_flex)
+{
+ expect(__builtin_object_size(normal->c, 1), 16);
+ expect(__builtin_object_size(trailing_1->c, 1), 4);
+ expect(__builtin_object_size(trailing_0->c, 1), 0);
+ expect(__builtin_object_size(trailing_flex->c, 1), -1);
+}
+
+int main(int argc, char *argv[])
+{
+ stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
+
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/pr101836_1.c b/gcc/testsuite/gcc.dg/pr101836_1.c
new file mode 100644
index 00000000000..30ea20427a5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr101836_1.c
@@ -0,0 +1,60 @@
+/* -fstrict-flex-array=3 is the strictest, only [] is treated as
+ flexible array. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-array=3" } */
+
+#include <stdio.h>
+
+#define expect(p, _v) do { \
+ size_t v = _v; \
+ if (p == v) \
+ printf("ok: %s == %zd\n", #p, p); \
+ else \
+ { \
+ printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
+ __builtin_abort (); \
+ } \
+} while (0);
+
+struct trailing_array_1 {
+ int a;
+ int b;
+ int c[4];
+};
+
+struct trailing_array_2 {
+ int a;
+ int b;
+ int c[1];
+};
+
+struct trailing_array_3 {
+ int a;
+ int b;
+ int c[0];
+};
+struct trailing_array_4 {
+ int a;
+ int b;
+ int c[];
+};
+
+void __attribute__((__noinline__)) stuff(
+ struct trailing_array_1 *normal,
+ struct trailing_array_2 *trailing_1,
+ struct trailing_array_3 *trailing_0,
+ struct trailing_array_4 *trailing_flex)
+{
+ expect(__builtin_object_size(normal->c, 1), 16);
+ expect(__builtin_object_size(trailing_1->c, 1), 4);
+ expect(__builtin_object_size(trailing_0->c, 1), 0);
+ expect(__builtin_object_size(trailing_flex->c, 1), -1);
+}
+
+int main(int argc, char *argv[])
+{
+ stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
+
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/pr101836_2.c b/gcc/testsuite/gcc.dg/pr101836_2.c
new file mode 100644
index 00000000000..ebbe88f433c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr101836_2.c
@@ -0,0 +1,60 @@
+/* When -fstrict-flex-array=2, only [] and [0] are treated as flexiable
+ arrays. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-array=2" } */
+
+#include <stdio.h>
+
+#define expect(p, _v) do { \
+ size_t v = _v; \
+ if (p == v) \
+ printf("ok: %s == %zd\n", #p, p); \
+ else \
+ { \
+ printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
+ __builtin_abort (); \
+ } \
+} while (0);
+
+struct trailing_array_1 {
+ int a;
+ int b;
+ int c[4];
+};
+
+struct trailing_array_2 {
+ int a;
+ int b;
+ int c[1];
+};
+
+struct trailing_array_3 {
+ int a;
+ int b;
+ int c[0];
+};
+struct trailing_array_4 {
+ int a;
+ int b;
+ int c[];
+};
+
+void __attribute__((__noinline__)) stuff(
+ struct trailing_array_1 *normal,
+ struct trailing_array_2 *trailing_1,
+ struct trailing_array_3 *trailing_0,
+ struct trailing_array_4 *trailing_flex)
+{
+ expect(__builtin_object_size(normal->c, 1), 16);
+ expect(__builtin_object_size(trailing_1->c, 1), 4);
+ expect(__builtin_object_size(trailing_0->c, 1), -1);
+ expect(__builtin_object_size(trailing_flex->c, 1), -1);
+}
+
+int main(int argc, char *argv[])
+{
+ stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
+
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/pr101836_3.c b/gcc/testsuite/gcc.dg/pr101836_3.c
new file mode 100644
index 00000000000..d4ba0afe5bc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr101836_3.c
@@ -0,0 +1,60 @@
+/* When -fstrict-flex-array=1, [], [0], and [1] are treated as flexible
+ arrays. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-array=1" } */
+
+#include <stdio.h>
+
+#define expect(p, _v) do { \
+ size_t v = _v; \
+ if (p == v) \
+ printf("ok: %s == %zd\n", #p, p); \
+ else \
+ { \
+ printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
+ __builtin_abort (); \
+ } \
+} while (0);
+
+struct trailing_array_1 {
+ int a;
+ int b;
+ int c[4];
+};
+
+struct trailing_array_2 {
+ int a;
+ int b;
+ int c[1];
+};
+
+struct trailing_array_3 {
+ int a;
+ int b;
+ int c[0];
+};
+struct trailing_array_4 {
+ int a;
+ int b;
+ int c[];
+};
+
+void __attribute__((__noinline__)) stuff(
+ struct trailing_array_1 *normal,
+ struct trailing_array_2 *trailing_1,
+ struct trailing_array_3 *trailing_0,
+ struct trailing_array_4 *trailing_flex)
+{
+ expect(__builtin_object_size(normal->c, 1), 16);
+ expect(__builtin_object_size(trailing_1->c, 1), -1);
+ expect(__builtin_object_size(trailing_0->c, 1), -1);
+ expect(__builtin_object_size(trailing_flex->c, 1), -1);
+}
+
+int main(int argc, char *argv[])
+{
+ stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
+
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/pr101836_4.c b/gcc/testsuite/gcc.dg/pr101836_4.c
new file mode 100644
index 00000000000..b10d3ce312d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr101836_4.c
@@ -0,0 +1,60 @@
+/* when -fstrict-flex-array=0, all trailing arrays are treated as
+ flexible arrays. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-array=0" } */
+
+#include <stdio.h>
+
+#define expect(p, _v) do { \
+ size_t v = _v; \
+ if (p == v) \
+ printf("ok: %s == %zd\n", #p, p); \
+ else \
+ { \
+ printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
+ __builtin_abort (); \
+ } \
+} while (0);
+
+struct trailing_array_1 {
+ int a;
+ int b;
+ int c[4];
+};
+
+struct trailing_array_2 {
+ int a;
+ int b;
+ int c[1];
+};
+
+struct trailing_array_3 {
+ int a;
+ int b;
+ int c[0];
+};
+struct trailing_array_4 {
+ int a;
+ int b;
+ int c[];
+};
+
+void __attribute__((__noinline__)) stuff(
+ struct trailing_array_1 *normal,
+ struct trailing_array_2 *trailing_1,
+ struct trailing_array_3 *trailing_0,
+ struct trailing_array_4 *trailing_flex)
+{
+ expect(__builtin_object_size(normal->c, 1), -1);
+ expect(__builtin_object_size(trailing_1->c, 1), -1);
+ expect(__builtin_object_size(trailing_0->c, 1), -1);
+ expect(__builtin_object_size(trailing_flex->c, 1), -1);
+}
+
+int main(int argc, char *argv[])
+{
+ stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
+
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/pr101836_5.c b/gcc/testsuite/gcc.dg/pr101836_5.c
new file mode 100644
index 00000000000..2f6b5f7ae1f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr101836_5.c
@@ -0,0 +1,60 @@
+/* -fno-strict-flex-array is aliased to -fstrict-flex-array=0,
+ all trailing arrays are treated as flexible array. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fno-strict-flex-array" } */
+
+#include <stdio.h>
+
+#define expect(p, _v) do { \
+ size_t v = _v; \
+ if (p == v) \
+ printf("ok: %s == %zd\n", #p, p); \
+ else \
+ { \
+ printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
+ __builtin_abort (); \
+ } \
+} while (0);
+
+struct trailing_array_1 {
+ int a;
+ int b;
+ int c[4];
+};
+
+struct trailing_array_2 {
+ int a;
+ int b;
+ int c[1];
+};
+
+struct trailing_array_3 {
+ int a;
+ int b;
+ int c[0];
+};
+struct trailing_array_4 {
+ int a;
+ int b;
+ int c[];
+};
+
+void __attribute__((__noinline__)) stuff(
+ struct trailing_array_1 *normal,
+ struct trailing_array_2 *trailing_1,
+ struct trailing_array_3 *trailing_0,
+ struct trailing_array_4 *trailing_flex)
+{
+ expect(__builtin_object_size(normal->c, 1), -1);
+ expect(__builtin_object_size(trailing_1->c, 1), -1);
+ expect(__builtin_object_size(trailing_0->c, 1), -1);
+ expect(__builtin_object_size(trailing_flex->c, 1), -1);
+}
+
+int main(int argc, char *argv[])
+{
+ stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
+
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/strict-flex-array-2.c b/gcc/testsuite/gcc.dg/strict-flex-array-2.c
new file mode 100644
index 00000000000..326ddcfeda5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/strict-flex-array-2.c
@@ -0,0 +1,60 @@
+/* test the combination of attribute strict_flex_array and option
+ -fstrict-flex-array: when both attribute and option specified,
+ attribute will have higher priority. */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-array=3" } */
+
+#include <stdio.h>
+
+#define expect(p, _v) do { \
+ size_t v = _v; \
+ if (p == v) \
+ printf("ok: %s == %zd\n", #p, p); \
+ else \
+ { \
+ printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
+ __builtin_abort (); \
+ } \
+} while (0);
+
+struct trailing_array_1 {
+ int a;
+ int b;
+ int c[4] __attribute__ ((strict_flex_array (0)));
+};
+
+struct trailing_array_2 {
+ int a;
+ int b;
+ int c[1] __attribute__ ((strict_flex_array (1)));
+};
+
+struct trailing_array_3 {
+ int a;
+ int b;
+ int c[0] __attribute__ ((strict_flex_array (2)));
+};
+struct trailing_array_4 {
+ int a;
+ int b;
+ int c[];
+};
+
+void __attribute__((__noinline__)) stuff(
+ struct trailing_array_1 *normal,
+ struct trailing_array_2 *trailing_1,
+ struct trailing_array_3 *trailing_0,
+ struct trailing_array_4 *trailing_flex)
+{
+ expect(__builtin_object_size(normal->c, 1), -1);
+ expect(__builtin_object_size(trailing_1->c, 1), -1);
+ expect(__builtin_object_size(trailing_0->c, 1), -1);
+ expect(__builtin_object_size(trailing_flex->c, 1), -1);
+}
+
+int main(int argc, char *argv[])
+{
+ stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
+
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/strict-flex-array-3.c b/gcc/testsuite/gcc.dg/strict-flex-array-3.c
new file mode 100644
index 00000000000..990c5bb6223
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/strict-flex-array-3.c
@@ -0,0 +1,60 @@
+/* test the combination of attribute strict_flex_array and option
+ -fstrict-flex-array: when both attribute and option specified,
+ attribute will have higher priority. */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-array=0" } */
+
+#include <stdio.h>
+
+#define expect(p, _v) do { \
+ size_t v = _v; \
+ if (p == v) \
+ printf("ok: %s == %zd\n", #p, p); \
+ else \
+ { \
+ printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
+ __builtin_abort (); \
+ } \
+} while (0);
+
+struct trailing_array_1 {
+ int a;
+ int b;
+ int c[4] __attribute__ ((strict_flex_array (1)));
+};
+
+struct trailing_array_2 {
+ int a;
+ int b;
+ int c[1] __attribute__ ((strict_flex_array (2)));
+};
+
+struct trailing_array_3 {
+ int a;
+ int b;
+ int c[0] __attribute__ ((strict_flex_array (3)));
+};
+struct trailing_array_4 {
+ int a;
+ int b;
+ int c[];
+};
+
+void __attribute__((__noinline__)) stuff(
+ struct trailing_array_1 *normal,
+ struct trailing_array_2 *trailing_1,
+ struct trailing_array_3 *trailing_0,
+ struct trailing_array_4 *trailing_flex)
+{
+ expect(__builtin_object_size(normal->c, 1), 16);
+ expect(__builtin_object_size(trailing_1->c, 1), 4);
+ expect(__builtin_object_size(trailing_0->c, 1), 0);
+ expect(__builtin_object_size(trailing_flex->c, 1), -1);
+}
+
+int main(int argc, char *argv[])
+{
+ stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
+
+ return 0;
+}
diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
index 4eb454a4a33..90710ecba72 100644
--- a/gcc/tree-object-size.cc
+++ b/gcc/tree-object-size.cc
@@ -604,9 +604,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF)
{
tree v = var;
- /* For &X->fld, compute object size only if fld isn't the last
- field, as struct { int i; char c[1]; } is often used instead
- of flexible array member. */
+ bool is_flexible_array_mem_ref = false;
+ /* For &X->fld, compute object size if fld isn't a flexible array
+ member. */
while (v && v != pt_var)
switch (TREE_CODE (v))
{
@@ -633,6 +633,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
v = NULL_TREE;
break;
}
+ is_flexible_array_mem_ref
+ = array_at_struct_end_p (v)
+ && !DECL_NOT_FLEXARRAY (TREE_OPERAND (v, 1));
while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
!= UNION_TYPE
@@ -645,12 +648,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
== RECORD_TYPE)
{
- tree fld_chain = DECL_CHAIN (TREE_OPERAND (v, 1));
- for (; fld_chain; fld_chain = DECL_CHAIN (fld_chain))
- if (TREE_CODE (fld_chain) == FIELD_DECL)
- break;
-
- if (fld_chain)
+ /* compute object size only if v is not a
+ flexible array member. */
+ if (!is_flexible_array_mem_ref)
{
v = NULL_TREE;
break;
--
2.27.0
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [GCC13][Patch][V2][2/2]Add a new option -fstrict-flex-array[=n] and attribute strict_flex_array(n) and use it in PR101836
2022-07-19 14:11 [GCC13][Patch][V2][2/2]Add a new option -fstrict-flex-array[=n] and attribute strict_flex_array(n) and use it in PR101836 Qing Zhao
@ 2022-07-28 7:28 ` Richard Biener
2022-07-29 14:23 ` Qing Zhao
2022-08-02 15:30 ` Kees Cook
1 sibling, 1 reply; 7+ messages in thread
From: Richard Biener @ 2022-07-28 7:28 UTC (permalink / raw)
To: Qing Zhao
Cc: gcc-patches Paul A Clarke via, jakub Jelinek, martin Sebor,
kees Cook, joseph
On Tue, 19 Jul 2022, Qing Zhao wrote:
> From a09f39ded462611286a44d9e8273de8342673ba2 Mon Sep 17 00:00:00 2001
> From: Qing Zhao <qing.zhao@oracle.com>
> Date: Mon, 18 Jul 2022 18:12:26 +0000
> Subject: [PATCH 2/2] Use new flag DECL_NOT_FLEXARRAY in __builtin_object_size
> [PR101836]
>
> Use new flag DECL_NOT_FLEXARRAY to determine whether the trailing array
> of a structure is flexible array member in __builtin_object_size.
>
> gcc/ChangeLog:
>
> PR tree-optimization/101836
> * tree-object-size.cc (addr_object_size): Use array_at_struct_end_p
> and DECL_NOT_FLEXARRAY to determine a flexible array member reference.
>
> gcc/testsuite/ChangeLog:
>
> PR tree-optimization/101836
> * gcc.dg/pr101836.c: New test.
> * gcc.dg/pr101836_1.c: New test.
> * gcc.dg/pr101836_2.c: New test.
> * gcc.dg/pr101836_3.c: New test.
> * gcc.dg/pr101836_4.c: New test.
> * gcc.dg/pr101836_5.c: New test.
> * gcc.dg/strict-flex-array-2.c: New test.
> * gcc.dg/strict-flex-array-3.c: New test.
> ---
> gcc/testsuite/gcc.dg/pr101836.c | 60 ++++++++++++++++++++++
> gcc/testsuite/gcc.dg/pr101836_1.c | 60 ++++++++++++++++++++++
> gcc/testsuite/gcc.dg/pr101836_2.c | 60 ++++++++++++++++++++++
> gcc/testsuite/gcc.dg/pr101836_3.c | 60 ++++++++++++++++++++++
> gcc/testsuite/gcc.dg/pr101836_4.c | 60 ++++++++++++++++++++++
> gcc/testsuite/gcc.dg/pr101836_5.c | 60 ++++++++++++++++++++++
> gcc/testsuite/gcc.dg/strict-flex-array-2.c | 60 ++++++++++++++++++++++
> gcc/testsuite/gcc.dg/strict-flex-array-3.c | 60 ++++++++++++++++++++++
> gcc/tree-object-size.cc | 18 +++----
> 9 files changed, 489 insertions(+), 9 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/pr101836.c
> create mode 100644 gcc/testsuite/gcc.dg/pr101836_1.c
> create mode 100644 gcc/testsuite/gcc.dg/pr101836_2.c
> create mode 100644 gcc/testsuite/gcc.dg/pr101836_3.c
> create mode 100644 gcc/testsuite/gcc.dg/pr101836_4.c
> create mode 100644 gcc/testsuite/gcc.dg/pr101836_5.c
> create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-2.c
> create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-3.c
>
> diff --git a/gcc/testsuite/gcc.dg/pr101836.c b/gcc/testsuite/gcc.dg/pr101836.c
> new file mode 100644
> index 00000000000..e5b4e5160a4
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836.c
> @@ -0,0 +1,60 @@
> +/* -fstrict-flex-array is aliased with -ftrict-flex-array=3, which is the
> + strictest, only [] is treated as flexible array. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-array" } */
> +
> +#include <stdio.h>
> +
> +#define expect(p, _v) do { \
> + size_t v = _v; \
> + if (p == v) \
> + printf("ok: %s == %zd\n", #p, p); \
> + else \
> + { \
> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> + __builtin_abort (); \
> + } \
> +} while (0);
> +
> +struct trailing_array_1 {
> + int a;
> + int b;
> + int c[4];
> +};
> +
> +struct trailing_array_2 {
> + int a;
> + int b;
> + int c[1];
> +};
> +
> +struct trailing_array_3 {
> + int a;
> + int b;
> + int c[0];
> +};
> +struct trailing_array_4 {
> + int a;
> + int b;
> + int c[];
> +};
> +
> +void __attribute__((__noinline__)) stuff(
> + struct trailing_array_1 *normal,
> + struct trailing_array_2 *trailing_1,
> + struct trailing_array_3 *trailing_0,
> + struct trailing_array_4 *trailing_flex)
> +{
> + expect(__builtin_object_size(normal->c, 1), 16);
> + expect(__builtin_object_size(trailing_1->c, 1), 4);
> + expect(__builtin_object_size(trailing_0->c, 1), 0);
> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> +
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.dg/pr101836_1.c b/gcc/testsuite/gcc.dg/pr101836_1.c
> new file mode 100644
> index 00000000000..30ea20427a5
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836_1.c
> @@ -0,0 +1,60 @@
> +/* -fstrict-flex-array=3 is the strictest, only [] is treated as
> + flexible array. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-array=3" } */
> +
> +#include <stdio.h>
> +
> +#define expect(p, _v) do { \
> + size_t v = _v; \
> + if (p == v) \
> + printf("ok: %s == %zd\n", #p, p); \
> + else \
> + { \
> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> + __builtin_abort (); \
> + } \
> +} while (0);
> +
> +struct trailing_array_1 {
> + int a;
> + int b;
> + int c[4];
> +};
> +
> +struct trailing_array_2 {
> + int a;
> + int b;
> + int c[1];
> +};
> +
> +struct trailing_array_3 {
> + int a;
> + int b;
> + int c[0];
> +};
> +struct trailing_array_4 {
> + int a;
> + int b;
> + int c[];
> +};
> +
> +void __attribute__((__noinline__)) stuff(
> + struct trailing_array_1 *normal,
> + struct trailing_array_2 *trailing_1,
> + struct trailing_array_3 *trailing_0,
> + struct trailing_array_4 *trailing_flex)
> +{
> + expect(__builtin_object_size(normal->c, 1), 16);
> + expect(__builtin_object_size(trailing_1->c, 1), 4);
> + expect(__builtin_object_size(trailing_0->c, 1), 0);
> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> +
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.dg/pr101836_2.c b/gcc/testsuite/gcc.dg/pr101836_2.c
> new file mode 100644
> index 00000000000..ebbe88f433c
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836_2.c
> @@ -0,0 +1,60 @@
> +/* When -fstrict-flex-array=2, only [] and [0] are treated as flexiable
> + arrays. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-array=2" } */
> +
> +#include <stdio.h>
> +
> +#define expect(p, _v) do { \
> + size_t v = _v; \
> + if (p == v) \
> + printf("ok: %s == %zd\n", #p, p); \
> + else \
> + { \
> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> + __builtin_abort (); \
> + } \
> +} while (0);
> +
> +struct trailing_array_1 {
> + int a;
> + int b;
> + int c[4];
> +};
> +
> +struct trailing_array_2 {
> + int a;
> + int b;
> + int c[1];
> +};
> +
> +struct trailing_array_3 {
> + int a;
> + int b;
> + int c[0];
> +};
> +struct trailing_array_4 {
> + int a;
> + int b;
> + int c[];
> +};
> +
> +void __attribute__((__noinline__)) stuff(
> + struct trailing_array_1 *normal,
> + struct trailing_array_2 *trailing_1,
> + struct trailing_array_3 *trailing_0,
> + struct trailing_array_4 *trailing_flex)
> +{
> + expect(__builtin_object_size(normal->c, 1), 16);
> + expect(__builtin_object_size(trailing_1->c, 1), 4);
> + expect(__builtin_object_size(trailing_0->c, 1), -1);
> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> +
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.dg/pr101836_3.c b/gcc/testsuite/gcc.dg/pr101836_3.c
> new file mode 100644
> index 00000000000..d4ba0afe5bc
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836_3.c
> @@ -0,0 +1,60 @@
> +/* When -fstrict-flex-array=1, [], [0], and [1] are treated as flexible
> + arrays. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-array=1" } */
> +
> +#include <stdio.h>
> +
> +#define expect(p, _v) do { \
> + size_t v = _v; \
> + if (p == v) \
> + printf("ok: %s == %zd\n", #p, p); \
> + else \
> + { \
> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> + __builtin_abort (); \
> + } \
> +} while (0);
> +
> +struct trailing_array_1 {
> + int a;
> + int b;
> + int c[4];
> +};
> +
> +struct trailing_array_2 {
> + int a;
> + int b;
> + int c[1];
> +};
> +
> +struct trailing_array_3 {
> + int a;
> + int b;
> + int c[0];
> +};
> +struct trailing_array_4 {
> + int a;
> + int b;
> + int c[];
> +};
> +
> +void __attribute__((__noinline__)) stuff(
> + struct trailing_array_1 *normal,
> + struct trailing_array_2 *trailing_1,
> + struct trailing_array_3 *trailing_0,
> + struct trailing_array_4 *trailing_flex)
> +{
> + expect(__builtin_object_size(normal->c, 1), 16);
> + expect(__builtin_object_size(trailing_1->c, 1), -1);
> + expect(__builtin_object_size(trailing_0->c, 1), -1);
> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> +
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.dg/pr101836_4.c b/gcc/testsuite/gcc.dg/pr101836_4.c
> new file mode 100644
> index 00000000000..b10d3ce312d
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836_4.c
> @@ -0,0 +1,60 @@
> +/* when -fstrict-flex-array=0, all trailing arrays are treated as
> + flexible arrays. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-array=0" } */
> +
> +#include <stdio.h>
> +
> +#define expect(p, _v) do { \
> + size_t v = _v; \
> + if (p == v) \
> + printf("ok: %s == %zd\n", #p, p); \
> + else \
> + { \
> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> + __builtin_abort (); \
> + } \
> +} while (0);
> +
> +struct trailing_array_1 {
> + int a;
> + int b;
> + int c[4];
> +};
> +
> +struct trailing_array_2 {
> + int a;
> + int b;
> + int c[1];
> +};
> +
> +struct trailing_array_3 {
> + int a;
> + int b;
> + int c[0];
> +};
> +struct trailing_array_4 {
> + int a;
> + int b;
> + int c[];
> +};
> +
> +void __attribute__((__noinline__)) stuff(
> + struct trailing_array_1 *normal,
> + struct trailing_array_2 *trailing_1,
> + struct trailing_array_3 *trailing_0,
> + struct trailing_array_4 *trailing_flex)
> +{
> + expect(__builtin_object_size(normal->c, 1), -1);
> + expect(__builtin_object_size(trailing_1->c, 1), -1);
> + expect(__builtin_object_size(trailing_0->c, 1), -1);
> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> +
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.dg/pr101836_5.c b/gcc/testsuite/gcc.dg/pr101836_5.c
> new file mode 100644
> index 00000000000..2f6b5f7ae1f
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836_5.c
> @@ -0,0 +1,60 @@
> +/* -fno-strict-flex-array is aliased to -fstrict-flex-array=0,
> + all trailing arrays are treated as flexible array. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fno-strict-flex-array" } */
> +
> +#include <stdio.h>
> +
> +#define expect(p, _v) do { \
> + size_t v = _v; \
> + if (p == v) \
> + printf("ok: %s == %zd\n", #p, p); \
> + else \
> + { \
> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> + __builtin_abort (); \
> + } \
> +} while (0);
> +
> +struct trailing_array_1 {
> + int a;
> + int b;
> + int c[4];
> +};
> +
> +struct trailing_array_2 {
> + int a;
> + int b;
> + int c[1];
> +};
> +
> +struct trailing_array_3 {
> + int a;
> + int b;
> + int c[0];
> +};
> +struct trailing_array_4 {
> + int a;
> + int b;
> + int c[];
> +};
> +
> +void __attribute__((__noinline__)) stuff(
> + struct trailing_array_1 *normal,
> + struct trailing_array_2 *trailing_1,
> + struct trailing_array_3 *trailing_0,
> + struct trailing_array_4 *trailing_flex)
> +{
> + expect(__builtin_object_size(normal->c, 1), -1);
> + expect(__builtin_object_size(trailing_1->c, 1), -1);
> + expect(__builtin_object_size(trailing_0->c, 1), -1);
> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> +
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.dg/strict-flex-array-2.c b/gcc/testsuite/gcc.dg/strict-flex-array-2.c
> new file mode 100644
> index 00000000000..326ddcfeda5
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-2.c
> @@ -0,0 +1,60 @@
> +/* test the combination of attribute strict_flex_array and option
> + -fstrict-flex-array: when both attribute and option specified,
> + attribute will have higher priority. */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-array=3" } */
> +
> +#include <stdio.h>
> +
> +#define expect(p, _v) do { \
> + size_t v = _v; \
> + if (p == v) \
> + printf("ok: %s == %zd\n", #p, p); \
> + else \
> + { \
> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> + __builtin_abort (); \
> + } \
> +} while (0);
> +
> +struct trailing_array_1 {
> + int a;
> + int b;
> + int c[4] __attribute__ ((strict_flex_array (0)));
> +};
> +
> +struct trailing_array_2 {
> + int a;
> + int b;
> + int c[1] __attribute__ ((strict_flex_array (1)));
> +};
> +
> +struct trailing_array_3 {
> + int a;
> + int b;
> + int c[0] __attribute__ ((strict_flex_array (2)));
> +};
> +struct trailing_array_4 {
> + int a;
> + int b;
> + int c[];
> +};
> +
> +void __attribute__((__noinline__)) stuff(
> + struct trailing_array_1 *normal,
> + struct trailing_array_2 *trailing_1,
> + struct trailing_array_3 *trailing_0,
> + struct trailing_array_4 *trailing_flex)
> +{
> + expect(__builtin_object_size(normal->c, 1), -1);
> + expect(__builtin_object_size(trailing_1->c, 1), -1);
> + expect(__builtin_object_size(trailing_0->c, 1), -1);
> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> +
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.dg/strict-flex-array-3.c b/gcc/testsuite/gcc.dg/strict-flex-array-3.c
> new file mode 100644
> index 00000000000..990c5bb6223
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-3.c
> @@ -0,0 +1,60 @@
> +/* test the combination of attribute strict_flex_array and option
> + -fstrict-flex-array: when both attribute and option specified,
> + attribute will have higher priority. */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-array=0" } */
> +
> +#include <stdio.h>
> +
> +#define expect(p, _v) do { \
> + size_t v = _v; \
> + if (p == v) \
> + printf("ok: %s == %zd\n", #p, p); \
> + else \
> + { \
> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> + __builtin_abort (); \
> + } \
> +} while (0);
> +
> +struct trailing_array_1 {
> + int a;
> + int b;
> + int c[4] __attribute__ ((strict_flex_array (1)));
> +};
> +
> +struct trailing_array_2 {
> + int a;
> + int b;
> + int c[1] __attribute__ ((strict_flex_array (2)));
> +};
> +
> +struct trailing_array_3 {
> + int a;
> + int b;
> + int c[0] __attribute__ ((strict_flex_array (3)));
> +};
> +struct trailing_array_4 {
> + int a;
> + int b;
> + int c[];
> +};
> +
> +void __attribute__((__noinline__)) stuff(
> + struct trailing_array_1 *normal,
> + struct trailing_array_2 *trailing_1,
> + struct trailing_array_3 *trailing_0,
> + struct trailing_array_4 *trailing_flex)
> +{
> + expect(__builtin_object_size(normal->c, 1), 16);
> + expect(__builtin_object_size(trailing_1->c, 1), 4);
> + expect(__builtin_object_size(trailing_0->c, 1), 0);
> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> +
> + return 0;
> +}
> diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
> index 4eb454a4a33..90710ecba72 100644
> --- a/gcc/tree-object-size.cc
> +++ b/gcc/tree-object-size.cc
> @@ -604,9 +604,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
> else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF)
> {
> tree v = var;
> - /* For &X->fld, compute object size only if fld isn't the last
> - field, as struct { int i; char c[1]; } is often used instead
> - of flexible array member. */
> + bool is_flexible_array_mem_ref = false;
> + /* For &X->fld, compute object size if fld isn't a flexible array
> + member. */
> while (v && v != pt_var)
> switch (TREE_CODE (v))
> {
> @@ -633,6 +633,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
> v = NULL_TREE;
> break;
> }
> + is_flexible_array_mem_ref
> + = array_at_struct_end_p (v)
> + && !DECL_NOT_FLEXARRAY (TREE_OPERAND (v, 1));
As said in the review for the first patch array_at_struct_end_p should
check DECL_NOT_FLEXARRAY.
OK with removing the extra check here.
> while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
> if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
> != UNION_TYPE
> @@ -645,12 +648,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
> && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
> == RECORD_TYPE)
> {
> - tree fld_chain = DECL_CHAIN (TREE_OPERAND (v, 1));
> - for (; fld_chain; fld_chain = DECL_CHAIN (fld_chain))
> - if (TREE_CODE (fld_chain) == FIELD_DECL)
> - break;
> -
> - if (fld_chain)
> + /* compute object size only if v is not a
> + flexible array member. */
> + if (!is_flexible_array_mem_ref)
> {
> v = NULL_TREE;
> break;
>
--
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
HRB 36809 (AG Nuernberg)
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [GCC13][Patch][V2][2/2]Add a new option -fstrict-flex-array[=n] and attribute strict_flex_array(n) and use it in PR101836
2022-07-28 7:28 ` Richard Biener
@ 2022-07-29 14:23 ` Qing Zhao
2022-08-01 7:13 ` Richard Biener
0 siblings, 1 reply; 7+ messages in thread
From: Qing Zhao @ 2022-07-29 14:23 UTC (permalink / raw)
To: Richard Biener
Cc: gcc-patches Paul A Clarke via, jakub Jelinek, martin Sebor,
kees Cook, joseph
> On Jul 28, 2022, at 3:28 AM, Richard Biener <rguenther@suse.de> wrote:
>
> On Tue, 19 Jul 2022, Qing Zhao wrote:
>
>> From a09f39ded462611286a44d9e8273de8342673ba2 Mon Sep 17 00:00:00 2001
>> From: Qing Zhao <qing.zhao@oracle.com>
>> Date: Mon, 18 Jul 2022 18:12:26 +0000
>> Subject: [PATCH 2/2] Use new flag DECL_NOT_FLEXARRAY in __builtin_object_size
>> [PR101836]
>>
>> Use new flag DECL_NOT_FLEXARRAY to determine whether the trailing array
>> of a structure is flexible array member in __builtin_object_size.
>>
>> gcc/ChangeLog:
>>
>> PR tree-optimization/101836
>> * tree-object-size.cc (addr_object_size): Use array_at_struct_end_p
>> and DECL_NOT_FLEXARRAY to determine a flexible array member reference.
>>
>> gcc/testsuite/ChangeLog:
>>
>> PR tree-optimization/101836
>> * gcc.dg/pr101836.c: New test.
>> * gcc.dg/pr101836_1.c: New test.
>> * gcc.dg/pr101836_2.c: New test.
>> * gcc.dg/pr101836_3.c: New test.
>> * gcc.dg/pr101836_4.c: New test.
>> * gcc.dg/pr101836_5.c: New test.
>> * gcc.dg/strict-flex-array-2.c: New test.
>> * gcc.dg/strict-flex-array-3.c: New test.
>> ---
>> gcc/testsuite/gcc.dg/pr101836.c | 60 ++++++++++++++++++++++
>> gcc/testsuite/gcc.dg/pr101836_1.c | 60 ++++++++++++++++++++++
>> gcc/testsuite/gcc.dg/pr101836_2.c | 60 ++++++++++++++++++++++
>> gcc/testsuite/gcc.dg/pr101836_3.c | 60 ++++++++++++++++++++++
>> gcc/testsuite/gcc.dg/pr101836_4.c | 60 ++++++++++++++++++++++
>> gcc/testsuite/gcc.dg/pr101836_5.c | 60 ++++++++++++++++++++++
>> gcc/testsuite/gcc.dg/strict-flex-array-2.c | 60 ++++++++++++++++++++++
>> gcc/testsuite/gcc.dg/strict-flex-array-3.c | 60 ++++++++++++++++++++++
>> gcc/tree-object-size.cc | 18 +++----
>> 9 files changed, 489 insertions(+), 9 deletions(-)
>> create mode 100644 gcc/testsuite/gcc.dg/pr101836.c
>> create mode 100644 gcc/testsuite/gcc.dg/pr101836_1.c
>> create mode 100644 gcc/testsuite/gcc.dg/pr101836_2.c
>> create mode 100644 gcc/testsuite/gcc.dg/pr101836_3.c
>> create mode 100644 gcc/testsuite/gcc.dg/pr101836_4.c
>> create mode 100644 gcc/testsuite/gcc.dg/pr101836_5.c
>> create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-2.c
>> create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-3.c
>>
>> diff --git a/gcc/testsuite/gcc.dg/pr101836.c b/gcc/testsuite/gcc.dg/pr101836.c
>> new file mode 100644
>> index 00000000000..e5b4e5160a4
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836.c
>> @@ -0,0 +1,60 @@
>> +/* -fstrict-flex-array is aliased with -ftrict-flex-array=3, which is the
>> + strictest, only [] is treated as flexible array. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-array" } */
>> +
>> +#include <stdio.h>
>> +
>> +#define expect(p, _v) do { \
>> + size_t v = _v; \
>> + if (p == v) \
>> + printf("ok: %s == %zd\n", #p, p); \
>> + else \
>> + { \
>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>> + __builtin_abort (); \
>> + } \
>> +} while (0);
>> +
>> +struct trailing_array_1 {
>> + int a;
>> + int b;
>> + int c[4];
>> +};
>> +
>> +struct trailing_array_2 {
>> + int a;
>> + int b;
>> + int c[1];
>> +};
>> +
>> +struct trailing_array_3 {
>> + int a;
>> + int b;
>> + int c[0];
>> +};
>> +struct trailing_array_4 {
>> + int a;
>> + int b;
>> + int c[];
>> +};
>> +
>> +void __attribute__((__noinline__)) stuff(
>> + struct trailing_array_1 *normal,
>> + struct trailing_array_2 *trailing_1,
>> + struct trailing_array_3 *trailing_0,
>> + struct trailing_array_4 *trailing_flex)
>> +{
>> + expect(__builtin_object_size(normal->c, 1), 16);
>> + expect(__builtin_object_size(trailing_1->c, 1), 4);
>> + expect(__builtin_object_size(trailing_0->c, 1), 0);
>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>> +
>> + return 0;
>> +}
>> diff --git a/gcc/testsuite/gcc.dg/pr101836_1.c b/gcc/testsuite/gcc.dg/pr101836_1.c
>> new file mode 100644
>> index 00000000000..30ea20427a5
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836_1.c
>> @@ -0,0 +1,60 @@
>> +/* -fstrict-flex-array=3 is the strictest, only [] is treated as
>> + flexible array. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-array=3" } */
>> +
>> +#include <stdio.h>
>> +
>> +#define expect(p, _v) do { \
>> + size_t v = _v; \
>> + if (p == v) \
>> + printf("ok: %s == %zd\n", #p, p); \
>> + else \
>> + { \
>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>> + __builtin_abort (); \
>> + } \
>> +} while (0);
>> +
>> +struct trailing_array_1 {
>> + int a;
>> + int b;
>> + int c[4];
>> +};
>> +
>> +struct trailing_array_2 {
>> + int a;
>> + int b;
>> + int c[1];
>> +};
>> +
>> +struct trailing_array_3 {
>> + int a;
>> + int b;
>> + int c[0];
>> +};
>> +struct trailing_array_4 {
>> + int a;
>> + int b;
>> + int c[];
>> +};
>> +
>> +void __attribute__((__noinline__)) stuff(
>> + struct trailing_array_1 *normal,
>> + struct trailing_array_2 *trailing_1,
>> + struct trailing_array_3 *trailing_0,
>> + struct trailing_array_4 *trailing_flex)
>> +{
>> + expect(__builtin_object_size(normal->c, 1), 16);
>> + expect(__builtin_object_size(trailing_1->c, 1), 4);
>> + expect(__builtin_object_size(trailing_0->c, 1), 0);
>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>> +
>> + return 0;
>> +}
>> diff --git a/gcc/testsuite/gcc.dg/pr101836_2.c b/gcc/testsuite/gcc.dg/pr101836_2.c
>> new file mode 100644
>> index 00000000000..ebbe88f433c
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836_2.c
>> @@ -0,0 +1,60 @@
>> +/* When -fstrict-flex-array=2, only [] and [0] are treated as flexiable
>> + arrays. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-array=2" } */
>> +
>> +#include <stdio.h>
>> +
>> +#define expect(p, _v) do { \
>> + size_t v = _v; \
>> + if (p == v) \
>> + printf("ok: %s == %zd\n", #p, p); \
>> + else \
>> + { \
>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>> + __builtin_abort (); \
>> + } \
>> +} while (0);
>> +
>> +struct trailing_array_1 {
>> + int a;
>> + int b;
>> + int c[4];
>> +};
>> +
>> +struct trailing_array_2 {
>> + int a;
>> + int b;
>> + int c[1];
>> +};
>> +
>> +struct trailing_array_3 {
>> + int a;
>> + int b;
>> + int c[0];
>> +};
>> +struct trailing_array_4 {
>> + int a;
>> + int b;
>> + int c[];
>> +};
>> +
>> +void __attribute__((__noinline__)) stuff(
>> + struct trailing_array_1 *normal,
>> + struct trailing_array_2 *trailing_1,
>> + struct trailing_array_3 *trailing_0,
>> + struct trailing_array_4 *trailing_flex)
>> +{
>> + expect(__builtin_object_size(normal->c, 1), 16);
>> + expect(__builtin_object_size(trailing_1->c, 1), 4);
>> + expect(__builtin_object_size(trailing_0->c, 1), -1);
>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>> +
>> + return 0;
>> +}
>> diff --git a/gcc/testsuite/gcc.dg/pr101836_3.c b/gcc/testsuite/gcc.dg/pr101836_3.c
>> new file mode 100644
>> index 00000000000..d4ba0afe5bc
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836_3.c
>> @@ -0,0 +1,60 @@
>> +/* When -fstrict-flex-array=1, [], [0], and [1] are treated as flexible
>> + arrays. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-array=1" } */
>> +
>> +#include <stdio.h>
>> +
>> +#define expect(p, _v) do { \
>> + size_t v = _v; \
>> + if (p == v) \
>> + printf("ok: %s == %zd\n", #p, p); \
>> + else \
>> + { \
>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>> + __builtin_abort (); \
>> + } \
>> +} while (0);
>> +
>> +struct trailing_array_1 {
>> + int a;
>> + int b;
>> + int c[4];
>> +};
>> +
>> +struct trailing_array_2 {
>> + int a;
>> + int b;
>> + int c[1];
>> +};
>> +
>> +struct trailing_array_3 {
>> + int a;
>> + int b;
>> + int c[0];
>> +};
>> +struct trailing_array_4 {
>> + int a;
>> + int b;
>> + int c[];
>> +};
>> +
>> +void __attribute__((__noinline__)) stuff(
>> + struct trailing_array_1 *normal,
>> + struct trailing_array_2 *trailing_1,
>> + struct trailing_array_3 *trailing_0,
>> + struct trailing_array_4 *trailing_flex)
>> +{
>> + expect(__builtin_object_size(normal->c, 1), 16);
>> + expect(__builtin_object_size(trailing_1->c, 1), -1);
>> + expect(__builtin_object_size(trailing_0->c, 1), -1);
>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>> +
>> + return 0;
>> +}
>> diff --git a/gcc/testsuite/gcc.dg/pr101836_4.c b/gcc/testsuite/gcc.dg/pr101836_4.c
>> new file mode 100644
>> index 00000000000..b10d3ce312d
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836_4.c
>> @@ -0,0 +1,60 @@
>> +/* when -fstrict-flex-array=0, all trailing arrays are treated as
>> + flexible arrays. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-array=0" } */
>> +
>> +#include <stdio.h>
>> +
>> +#define expect(p, _v) do { \
>> + size_t v = _v; \
>> + if (p == v) \
>> + printf("ok: %s == %zd\n", #p, p); \
>> + else \
>> + { \
>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>> + __builtin_abort (); \
>> + } \
>> +} while (0);
>> +
>> +struct trailing_array_1 {
>> + int a;
>> + int b;
>> + int c[4];
>> +};
>> +
>> +struct trailing_array_2 {
>> + int a;
>> + int b;
>> + int c[1];
>> +};
>> +
>> +struct trailing_array_3 {
>> + int a;
>> + int b;
>> + int c[0];
>> +};
>> +struct trailing_array_4 {
>> + int a;
>> + int b;
>> + int c[];
>> +};
>> +
>> +void __attribute__((__noinline__)) stuff(
>> + struct trailing_array_1 *normal,
>> + struct trailing_array_2 *trailing_1,
>> + struct trailing_array_3 *trailing_0,
>> + struct trailing_array_4 *trailing_flex)
>> +{
>> + expect(__builtin_object_size(normal->c, 1), -1);
>> + expect(__builtin_object_size(trailing_1->c, 1), -1);
>> + expect(__builtin_object_size(trailing_0->c, 1), -1);
>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>> +
>> + return 0;
>> +}
>> diff --git a/gcc/testsuite/gcc.dg/pr101836_5.c b/gcc/testsuite/gcc.dg/pr101836_5.c
>> new file mode 100644
>> index 00000000000..2f6b5f7ae1f
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836_5.c
>> @@ -0,0 +1,60 @@
>> +/* -fno-strict-flex-array is aliased to -fstrict-flex-array=0,
>> + all trailing arrays are treated as flexible array. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fno-strict-flex-array" } */
>> +
>> +#include <stdio.h>
>> +
>> +#define expect(p, _v) do { \
>> + size_t v = _v; \
>> + if (p == v) \
>> + printf("ok: %s == %zd\n", #p, p); \
>> + else \
>> + { \
>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>> + __builtin_abort (); \
>> + } \
>> +} while (0);
>> +
>> +struct trailing_array_1 {
>> + int a;
>> + int b;
>> + int c[4];
>> +};
>> +
>> +struct trailing_array_2 {
>> + int a;
>> + int b;
>> + int c[1];
>> +};
>> +
>> +struct trailing_array_3 {
>> + int a;
>> + int b;
>> + int c[0];
>> +};
>> +struct trailing_array_4 {
>> + int a;
>> + int b;
>> + int c[];
>> +};
>> +
>> +void __attribute__((__noinline__)) stuff(
>> + struct trailing_array_1 *normal,
>> + struct trailing_array_2 *trailing_1,
>> + struct trailing_array_3 *trailing_0,
>> + struct trailing_array_4 *trailing_flex)
>> +{
>> + expect(__builtin_object_size(normal->c, 1), -1);
>> + expect(__builtin_object_size(trailing_1->c, 1), -1);
>> + expect(__builtin_object_size(trailing_0->c, 1), -1);
>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>> +
>> + return 0;
>> +}
>> diff --git a/gcc/testsuite/gcc.dg/strict-flex-array-2.c b/gcc/testsuite/gcc.dg/strict-flex-array-2.c
>> new file mode 100644
>> index 00000000000..326ddcfeda5
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-2.c
>> @@ -0,0 +1,60 @@
>> +/* test the combination of attribute strict_flex_array and option
>> + -fstrict-flex-array: when both attribute and option specified,
>> + attribute will have higher priority. */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-array=3" } */
>> +
>> +#include <stdio.h>
>> +
>> +#define expect(p, _v) do { \
>> + size_t v = _v; \
>> + if (p == v) \
>> + printf("ok: %s == %zd\n", #p, p); \
>> + else \
>> + { \
>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>> + __builtin_abort (); \
>> + } \
>> +} while (0);
>> +
>> +struct trailing_array_1 {
>> + int a;
>> + int b;
>> + int c[4] __attribute__ ((strict_flex_array (0)));
>> +};
>> +
>> +struct trailing_array_2 {
>> + int a;
>> + int b;
>> + int c[1] __attribute__ ((strict_flex_array (1)));
>> +};
>> +
>> +struct trailing_array_3 {
>> + int a;
>> + int b;
>> + int c[0] __attribute__ ((strict_flex_array (2)));
>> +};
>> +struct trailing_array_4 {
>> + int a;
>> + int b;
>> + int c[];
>> +};
>> +
>> +void __attribute__((__noinline__)) stuff(
>> + struct trailing_array_1 *normal,
>> + struct trailing_array_2 *trailing_1,
>> + struct trailing_array_3 *trailing_0,
>> + struct trailing_array_4 *trailing_flex)
>> +{
>> + expect(__builtin_object_size(normal->c, 1), -1);
>> + expect(__builtin_object_size(trailing_1->c, 1), -1);
>> + expect(__builtin_object_size(trailing_0->c, 1), -1);
>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>> +
>> + return 0;
>> +}
>> diff --git a/gcc/testsuite/gcc.dg/strict-flex-array-3.c b/gcc/testsuite/gcc.dg/strict-flex-array-3.c
>> new file mode 100644
>> index 00000000000..990c5bb6223
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-3.c
>> @@ -0,0 +1,60 @@
>> +/* test the combination of attribute strict_flex_array and option
>> + -fstrict-flex-array: when both attribute and option specified,
>> + attribute will have higher priority. */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-array=0" } */
>> +
>> +#include <stdio.h>
>> +
>> +#define expect(p, _v) do { \
>> + size_t v = _v; \
>> + if (p == v) \
>> + printf("ok: %s == %zd\n", #p, p); \
>> + else \
>> + { \
>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>> + __builtin_abort (); \
>> + } \
>> +} while (0);
>> +
>> +struct trailing_array_1 {
>> + int a;
>> + int b;
>> + int c[4] __attribute__ ((strict_flex_array (1)));
>> +};
>> +
>> +struct trailing_array_2 {
>> + int a;
>> + int b;
>> + int c[1] __attribute__ ((strict_flex_array (2)));
>> +};
>> +
>> +struct trailing_array_3 {
>> + int a;
>> + int b;
>> + int c[0] __attribute__ ((strict_flex_array (3)));
>> +};
>> +struct trailing_array_4 {
>> + int a;
>> + int b;
>> + int c[];
>> +};
>> +
>> +void __attribute__((__noinline__)) stuff(
>> + struct trailing_array_1 *normal,
>> + struct trailing_array_2 *trailing_1,
>> + struct trailing_array_3 *trailing_0,
>> + struct trailing_array_4 *trailing_flex)
>> +{
>> + expect(__builtin_object_size(normal->c, 1), 16);
>> + expect(__builtin_object_size(trailing_1->c, 1), 4);
>> + expect(__builtin_object_size(trailing_0->c, 1), 0);
>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>> +
>> + return 0;
>> +}
>> diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
>> index 4eb454a4a33..90710ecba72 100644
>> --- a/gcc/tree-object-size.cc
>> +++ b/gcc/tree-object-size.cc
>> @@ -604,9 +604,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
>> else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF)
>> {
>> tree v = var;
>> - /* For &X->fld, compute object size only if fld isn't the last
>> - field, as struct { int i; char c[1]; } is often used instead
>> - of flexible array member. */
>> + bool is_flexible_array_mem_ref = false;
>> + /* For &X->fld, compute object size if fld isn't a flexible array
>> + member. */
>> while (v && v != pt_var)
>> switch (TREE_CODE (v))
>> {
>> @@ -633,6 +633,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
>> v = NULL_TREE;
>> break;
>> }
>> + is_flexible_array_mem_ref
>> + = array_at_struct_end_p (v)
>> + && !DECL_NOT_FLEXARRAY (TREE_OPERAND (v, 1));
>
> As said in the review for the first patch array_at_struct_end_p should
> check DECL_NOT_FLEXARRAY.
Okay.
Then, should we change the name of “array_at_struct_end_p” to a more descriptive name, for example,”flexible_array_member_p”? Otherwise,
It’s really confusing.
>
> OK with removing the extra check here.
Okay.
thanks.
Qing
>
>> while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
>> if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
>> != UNION_TYPE
>> @@ -645,12 +648,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
>> && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
>> == RECORD_TYPE)
>> {
>> - tree fld_chain = DECL_CHAIN (TREE_OPERAND (v, 1));
>> - for (; fld_chain; fld_chain = DECL_CHAIN (fld_chain))
>> - if (TREE_CODE (fld_chain) == FIELD_DECL)
>> - break;
>> -
>> - if (fld_chain)
>> + /* compute object size only if v is not a
>> + flexible array member. */
>> + if (!is_flexible_array_mem_ref)
>> {
>> v = NULL_TREE;
>> break;
>>
>
> --
> Richard Biener <rguenther@suse.de>
> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
> Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
> HRB 36809 (AG Nuernberg)
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [GCC13][Patch][V2][2/2]Add a new option -fstrict-flex-array[=n] and attribute strict_flex_array(n) and use it in PR101836
2022-07-29 14:23 ` Qing Zhao
@ 2022-08-01 7:13 ` Richard Biener
2022-08-01 14:14 ` Qing Zhao
0 siblings, 1 reply; 7+ messages in thread
From: Richard Biener @ 2022-08-01 7:13 UTC (permalink / raw)
To: Qing Zhao
Cc: gcc-patches Paul A Clarke via, jakub Jelinek, martin Sebor,
kees Cook, joseph
On Fri, 29 Jul 2022, Qing Zhao wrote:
>
>
> > On Jul 28, 2022, at 3:28 AM, Richard Biener <rguenther@suse.de> wrote:
> >
> > On Tue, 19 Jul 2022, Qing Zhao wrote:
> >
> >> From a09f39ded462611286a44d9e8273de8342673ba2 Mon Sep 17 00:00:00 2001
> >> From: Qing Zhao <qing.zhao@oracle.com>
> >> Date: Mon, 18 Jul 2022 18:12:26 +0000
> >> Subject: [PATCH 2/2] Use new flag DECL_NOT_FLEXARRAY in __builtin_object_size
> >> [PR101836]
> >>
> >> Use new flag DECL_NOT_FLEXARRAY to determine whether the trailing array
> >> of a structure is flexible array member in __builtin_object_size.
> >>
> >> gcc/ChangeLog:
> >>
> >> PR tree-optimization/101836
> >> * tree-object-size.cc (addr_object_size): Use array_at_struct_end_p
> >> and DECL_NOT_FLEXARRAY to determine a flexible array member reference.
> >>
> >> gcc/testsuite/ChangeLog:
> >>
> >> PR tree-optimization/101836
> >> * gcc.dg/pr101836.c: New test.
> >> * gcc.dg/pr101836_1.c: New test.
> >> * gcc.dg/pr101836_2.c: New test.
> >> * gcc.dg/pr101836_3.c: New test.
> >> * gcc.dg/pr101836_4.c: New test.
> >> * gcc.dg/pr101836_5.c: New test.
> >> * gcc.dg/strict-flex-array-2.c: New test.
> >> * gcc.dg/strict-flex-array-3.c: New test.
> >> ---
> >> gcc/testsuite/gcc.dg/pr101836.c | 60 ++++++++++++++++++++++
> >> gcc/testsuite/gcc.dg/pr101836_1.c | 60 ++++++++++++++++++++++
> >> gcc/testsuite/gcc.dg/pr101836_2.c | 60 ++++++++++++++++++++++
> >> gcc/testsuite/gcc.dg/pr101836_3.c | 60 ++++++++++++++++++++++
> >> gcc/testsuite/gcc.dg/pr101836_4.c | 60 ++++++++++++++++++++++
> >> gcc/testsuite/gcc.dg/pr101836_5.c | 60 ++++++++++++++++++++++
> >> gcc/testsuite/gcc.dg/strict-flex-array-2.c | 60 ++++++++++++++++++++++
> >> gcc/testsuite/gcc.dg/strict-flex-array-3.c | 60 ++++++++++++++++++++++
> >> gcc/tree-object-size.cc | 18 +++----
> >> 9 files changed, 489 insertions(+), 9 deletions(-)
> >> create mode 100644 gcc/testsuite/gcc.dg/pr101836.c
> >> create mode 100644 gcc/testsuite/gcc.dg/pr101836_1.c
> >> create mode 100644 gcc/testsuite/gcc.dg/pr101836_2.c
> >> create mode 100644 gcc/testsuite/gcc.dg/pr101836_3.c
> >> create mode 100644 gcc/testsuite/gcc.dg/pr101836_4.c
> >> create mode 100644 gcc/testsuite/gcc.dg/pr101836_5.c
> >> create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-2.c
> >> create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-3.c
> >>
> >> diff --git a/gcc/testsuite/gcc.dg/pr101836.c b/gcc/testsuite/gcc.dg/pr101836.c
> >> new file mode 100644
> >> index 00000000000..e5b4e5160a4
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/pr101836.c
> >> @@ -0,0 +1,60 @@
> >> +/* -fstrict-flex-array is aliased with -ftrict-flex-array=3, which is the
> >> + strictest, only [] is treated as flexible array. */
> >> +/* PR tree-optimization/101836 */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2 -fstrict-flex-array" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +#define expect(p, _v) do { \
> >> + size_t v = _v; \
> >> + if (p == v) \
> >> + printf("ok: %s == %zd\n", #p, p); \
> >> + else \
> >> + { \
> >> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> >> + __builtin_abort (); \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct trailing_array_1 {
> >> + int a;
> >> + int b;
> >> + int c[4];
> >> +};
> >> +
> >> +struct trailing_array_2 {
> >> + int a;
> >> + int b;
> >> + int c[1];
> >> +};
> >> +
> >> +struct trailing_array_3 {
> >> + int a;
> >> + int b;
> >> + int c[0];
> >> +};
> >> +struct trailing_array_4 {
> >> + int a;
> >> + int b;
> >> + int c[];
> >> +};
> >> +
> >> +void __attribute__((__noinline__)) stuff(
> >> + struct trailing_array_1 *normal,
> >> + struct trailing_array_2 *trailing_1,
> >> + struct trailing_array_3 *trailing_0,
> >> + struct trailing_array_4 *trailing_flex)
> >> +{
> >> + expect(__builtin_object_size(normal->c, 1), 16);
> >> + expect(__builtin_object_size(trailing_1->c, 1), 4);
> >> + expect(__builtin_object_size(trailing_0->c, 1), 0);
> >> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> >> +}
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/testsuite/gcc.dg/pr101836_1.c b/gcc/testsuite/gcc.dg/pr101836_1.c
> >> new file mode 100644
> >> index 00000000000..30ea20427a5
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/pr101836_1.c
> >> @@ -0,0 +1,60 @@
> >> +/* -fstrict-flex-array=3 is the strictest, only [] is treated as
> >> + flexible array. */
> >> +/* PR tree-optimization/101836 */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2 -fstrict-flex-array=3" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +#define expect(p, _v) do { \
> >> + size_t v = _v; \
> >> + if (p == v) \
> >> + printf("ok: %s == %zd\n", #p, p); \
> >> + else \
> >> + { \
> >> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> >> + __builtin_abort (); \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct trailing_array_1 {
> >> + int a;
> >> + int b;
> >> + int c[4];
> >> +};
> >> +
> >> +struct trailing_array_2 {
> >> + int a;
> >> + int b;
> >> + int c[1];
> >> +};
> >> +
> >> +struct trailing_array_3 {
> >> + int a;
> >> + int b;
> >> + int c[0];
> >> +};
> >> +struct trailing_array_4 {
> >> + int a;
> >> + int b;
> >> + int c[];
> >> +};
> >> +
> >> +void __attribute__((__noinline__)) stuff(
> >> + struct trailing_array_1 *normal,
> >> + struct trailing_array_2 *trailing_1,
> >> + struct trailing_array_3 *trailing_0,
> >> + struct trailing_array_4 *trailing_flex)
> >> +{
> >> + expect(__builtin_object_size(normal->c, 1), 16);
> >> + expect(__builtin_object_size(trailing_1->c, 1), 4);
> >> + expect(__builtin_object_size(trailing_0->c, 1), 0);
> >> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> >> +}
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/testsuite/gcc.dg/pr101836_2.c b/gcc/testsuite/gcc.dg/pr101836_2.c
> >> new file mode 100644
> >> index 00000000000..ebbe88f433c
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/pr101836_2.c
> >> @@ -0,0 +1,60 @@
> >> +/* When -fstrict-flex-array=2, only [] and [0] are treated as flexiable
> >> + arrays. */
> >> +/* PR tree-optimization/101836 */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2 -fstrict-flex-array=2" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +#define expect(p, _v) do { \
> >> + size_t v = _v; \
> >> + if (p == v) \
> >> + printf("ok: %s == %zd\n", #p, p); \
> >> + else \
> >> + { \
> >> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> >> + __builtin_abort (); \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct trailing_array_1 {
> >> + int a;
> >> + int b;
> >> + int c[4];
> >> +};
> >> +
> >> +struct trailing_array_2 {
> >> + int a;
> >> + int b;
> >> + int c[1];
> >> +};
> >> +
> >> +struct trailing_array_3 {
> >> + int a;
> >> + int b;
> >> + int c[0];
> >> +};
> >> +struct trailing_array_4 {
> >> + int a;
> >> + int b;
> >> + int c[];
> >> +};
> >> +
> >> +void __attribute__((__noinline__)) stuff(
> >> + struct trailing_array_1 *normal,
> >> + struct trailing_array_2 *trailing_1,
> >> + struct trailing_array_3 *trailing_0,
> >> + struct trailing_array_4 *trailing_flex)
> >> +{
> >> + expect(__builtin_object_size(normal->c, 1), 16);
> >> + expect(__builtin_object_size(trailing_1->c, 1), 4);
> >> + expect(__builtin_object_size(trailing_0->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> >> +}
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/testsuite/gcc.dg/pr101836_3.c b/gcc/testsuite/gcc.dg/pr101836_3.c
> >> new file mode 100644
> >> index 00000000000..d4ba0afe5bc
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/pr101836_3.c
> >> @@ -0,0 +1,60 @@
> >> +/* When -fstrict-flex-array=1, [], [0], and [1] are treated as flexible
> >> + arrays. */
> >> +/* PR tree-optimization/101836 */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2 -fstrict-flex-array=1" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +#define expect(p, _v) do { \
> >> + size_t v = _v; \
> >> + if (p == v) \
> >> + printf("ok: %s == %zd\n", #p, p); \
> >> + else \
> >> + { \
> >> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> >> + __builtin_abort (); \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct trailing_array_1 {
> >> + int a;
> >> + int b;
> >> + int c[4];
> >> +};
> >> +
> >> +struct trailing_array_2 {
> >> + int a;
> >> + int b;
> >> + int c[1];
> >> +};
> >> +
> >> +struct trailing_array_3 {
> >> + int a;
> >> + int b;
> >> + int c[0];
> >> +};
> >> +struct trailing_array_4 {
> >> + int a;
> >> + int b;
> >> + int c[];
> >> +};
> >> +
> >> +void __attribute__((__noinline__)) stuff(
> >> + struct trailing_array_1 *normal,
> >> + struct trailing_array_2 *trailing_1,
> >> + struct trailing_array_3 *trailing_0,
> >> + struct trailing_array_4 *trailing_flex)
> >> +{
> >> + expect(__builtin_object_size(normal->c, 1), 16);
> >> + expect(__builtin_object_size(trailing_1->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_0->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> >> +}
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/testsuite/gcc.dg/pr101836_4.c b/gcc/testsuite/gcc.dg/pr101836_4.c
> >> new file mode 100644
> >> index 00000000000..b10d3ce312d
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/pr101836_4.c
> >> @@ -0,0 +1,60 @@
> >> +/* when -fstrict-flex-array=0, all trailing arrays are treated as
> >> + flexible arrays. */
> >> +/* PR tree-optimization/101836 */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2 -fstrict-flex-array=0" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +#define expect(p, _v) do { \
> >> + size_t v = _v; \
> >> + if (p == v) \
> >> + printf("ok: %s == %zd\n", #p, p); \
> >> + else \
> >> + { \
> >> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> >> + __builtin_abort (); \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct trailing_array_1 {
> >> + int a;
> >> + int b;
> >> + int c[4];
> >> +};
> >> +
> >> +struct trailing_array_2 {
> >> + int a;
> >> + int b;
> >> + int c[1];
> >> +};
> >> +
> >> +struct trailing_array_3 {
> >> + int a;
> >> + int b;
> >> + int c[0];
> >> +};
> >> +struct trailing_array_4 {
> >> + int a;
> >> + int b;
> >> + int c[];
> >> +};
> >> +
> >> +void __attribute__((__noinline__)) stuff(
> >> + struct trailing_array_1 *normal,
> >> + struct trailing_array_2 *trailing_1,
> >> + struct trailing_array_3 *trailing_0,
> >> + struct trailing_array_4 *trailing_flex)
> >> +{
> >> + expect(__builtin_object_size(normal->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_1->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_0->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> >> +}
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/testsuite/gcc.dg/pr101836_5.c b/gcc/testsuite/gcc.dg/pr101836_5.c
> >> new file mode 100644
> >> index 00000000000..2f6b5f7ae1f
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/pr101836_5.c
> >> @@ -0,0 +1,60 @@
> >> +/* -fno-strict-flex-array is aliased to -fstrict-flex-array=0,
> >> + all trailing arrays are treated as flexible array. */
> >> +/* PR tree-optimization/101836 */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2 -fno-strict-flex-array" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +#define expect(p, _v) do { \
> >> + size_t v = _v; \
> >> + if (p == v) \
> >> + printf("ok: %s == %zd\n", #p, p); \
> >> + else \
> >> + { \
> >> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> >> + __builtin_abort (); \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct trailing_array_1 {
> >> + int a;
> >> + int b;
> >> + int c[4];
> >> +};
> >> +
> >> +struct trailing_array_2 {
> >> + int a;
> >> + int b;
> >> + int c[1];
> >> +};
> >> +
> >> +struct trailing_array_3 {
> >> + int a;
> >> + int b;
> >> + int c[0];
> >> +};
> >> +struct trailing_array_4 {
> >> + int a;
> >> + int b;
> >> + int c[];
> >> +};
> >> +
> >> +void __attribute__((__noinline__)) stuff(
> >> + struct trailing_array_1 *normal,
> >> + struct trailing_array_2 *trailing_1,
> >> + struct trailing_array_3 *trailing_0,
> >> + struct trailing_array_4 *trailing_flex)
> >> +{
> >> + expect(__builtin_object_size(normal->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_1->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_0->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> >> +}
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/testsuite/gcc.dg/strict-flex-array-2.c b/gcc/testsuite/gcc.dg/strict-flex-array-2.c
> >> new file mode 100644
> >> index 00000000000..326ddcfeda5
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-2.c
> >> @@ -0,0 +1,60 @@
> >> +/* test the combination of attribute strict_flex_array and option
> >> + -fstrict-flex-array: when both attribute and option specified,
> >> + attribute will have higher priority. */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2 -fstrict-flex-array=3" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +#define expect(p, _v) do { \
> >> + size_t v = _v; \
> >> + if (p == v) \
> >> + printf("ok: %s == %zd\n", #p, p); \
> >> + else \
> >> + { \
> >> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> >> + __builtin_abort (); \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct trailing_array_1 {
> >> + int a;
> >> + int b;
> >> + int c[4] __attribute__ ((strict_flex_array (0)));
> >> +};
> >> +
> >> +struct trailing_array_2 {
> >> + int a;
> >> + int b;
> >> + int c[1] __attribute__ ((strict_flex_array (1)));
> >> +};
> >> +
> >> +struct trailing_array_3 {
> >> + int a;
> >> + int b;
> >> + int c[0] __attribute__ ((strict_flex_array (2)));
> >> +};
> >> +struct trailing_array_4 {
> >> + int a;
> >> + int b;
> >> + int c[];
> >> +};
> >> +
> >> +void __attribute__((__noinline__)) stuff(
> >> + struct trailing_array_1 *normal,
> >> + struct trailing_array_2 *trailing_1,
> >> + struct trailing_array_3 *trailing_0,
> >> + struct trailing_array_4 *trailing_flex)
> >> +{
> >> + expect(__builtin_object_size(normal->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_1->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_0->c, 1), -1);
> >> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> >> +}
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/testsuite/gcc.dg/strict-flex-array-3.c b/gcc/testsuite/gcc.dg/strict-flex-array-3.c
> >> new file mode 100644
> >> index 00000000000..990c5bb6223
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-3.c
> >> @@ -0,0 +1,60 @@
> >> +/* test the combination of attribute strict_flex_array and option
> >> + -fstrict-flex-array: when both attribute and option specified,
> >> + attribute will have higher priority. */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2 -fstrict-flex-array=0" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +#define expect(p, _v) do { \
> >> + size_t v = _v; \
> >> + if (p == v) \
> >> + printf("ok: %s == %zd\n", #p, p); \
> >> + else \
> >> + { \
> >> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
> >> + __builtin_abort (); \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct trailing_array_1 {
> >> + int a;
> >> + int b;
> >> + int c[4] __attribute__ ((strict_flex_array (1)));
> >> +};
> >> +
> >> +struct trailing_array_2 {
> >> + int a;
> >> + int b;
> >> + int c[1] __attribute__ ((strict_flex_array (2)));
> >> +};
> >> +
> >> +struct trailing_array_3 {
> >> + int a;
> >> + int b;
> >> + int c[0] __attribute__ ((strict_flex_array (3)));
> >> +};
> >> +struct trailing_array_4 {
> >> + int a;
> >> + int b;
> >> + int c[];
> >> +};
> >> +
> >> +void __attribute__((__noinline__)) stuff(
> >> + struct trailing_array_1 *normal,
> >> + struct trailing_array_2 *trailing_1,
> >> + struct trailing_array_3 *trailing_0,
> >> + struct trailing_array_4 *trailing_flex)
> >> +{
> >> + expect(__builtin_object_size(normal->c, 1), 16);
> >> + expect(__builtin_object_size(trailing_1->c, 1), 4);
> >> + expect(__builtin_object_size(trailing_0->c, 1), 0);
> >> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
> >> +}
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
> >> index 4eb454a4a33..90710ecba72 100644
> >> --- a/gcc/tree-object-size.cc
> >> +++ b/gcc/tree-object-size.cc
> >> @@ -604,9 +604,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
> >> else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF)
> >> {
> >> tree v = var;
> >> - /* For &X->fld, compute object size only if fld isn't the last
> >> - field, as struct { int i; char c[1]; } is often used instead
> >> - of flexible array member. */
> >> + bool is_flexible_array_mem_ref = false;
> >> + /* For &X->fld, compute object size if fld isn't a flexible array
> >> + member. */
> >> while (v && v != pt_var)
> >> switch (TREE_CODE (v))
> >> {
> >> @@ -633,6 +633,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
> >> v = NULL_TREE;
> >> break;
> >> }
> >> + is_flexible_array_mem_ref
> >> + = array_at_struct_end_p (v)
> >> + && !DECL_NOT_FLEXARRAY (TREE_OPERAND (v, 1));
> >
> > As said in the review for the first patch array_at_struct_end_p should
> > check DECL_NOT_FLEXARRAY.
> Okay.
>
> Then, should we change the name of “array_at_struct_end_p” to a more
> descriptive name, for example,”flexible_array_member_p”? Otherwise, It’s
> really confusing.
It has been that way since forever, so please don't (at least not as
part of this series).
>
>
> >
> > OK with removing the extra check here.
>
> Okay.
>
>
> thanks.
>
> Qing
> >
> >> while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
> >> if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
> >> != UNION_TYPE
> >> @@ -645,12 +648,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
> >> && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
> >> == RECORD_TYPE)
> >> {
> >> - tree fld_chain = DECL_CHAIN (TREE_OPERAND (v, 1));
> >> - for (; fld_chain; fld_chain = DECL_CHAIN (fld_chain))
> >> - if (TREE_CODE (fld_chain) == FIELD_DECL)
> >> - break;
> >> -
> >> - if (fld_chain)
> >> + /* compute object size only if v is not a
> >> + flexible array member. */
> >> + if (!is_flexible_array_mem_ref)
> >> {
> >> v = NULL_TREE;
> >> break;
> >>
> >
> > --
> > Richard Biener <rguenther@suse.de>
> > SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
> > Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
> > HRB 36809 (AG Nuernberg)
>
>
--
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
HRB 36809 (AG Nuernberg)
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [GCC13][Patch][V2][2/2]Add a new option -fstrict-flex-array[=n] and attribute strict_flex_array(n) and use it in PR101836
2022-08-01 7:13 ` Richard Biener
@ 2022-08-01 14:14 ` Qing Zhao
0 siblings, 0 replies; 7+ messages in thread
From: Qing Zhao @ 2022-08-01 14:14 UTC (permalink / raw)
To: Richard Biener
Cc: gcc-patches Paul A Clarke via, jakub Jelinek, martin Sebor,
kees Cook, joseph
> On Aug 1, 2022, at 3:13 AM, Richard Biener <rguenther@suse.de> wrote:
>
> On Fri, 29 Jul 2022, Qing Zhao wrote:
>
>>
>>
>>> On Jul 28, 2022, at 3:28 AM, Richard Biener <rguenther@suse.de> wrote:
>>>
>>> On Tue, 19 Jul 2022, Qing Zhao wrote:
>>>
>>>> From a09f39ded462611286a44d9e8273de8342673ba2 Mon Sep 17 00:00:00 2001
>>>> From: Qing Zhao <qing.zhao@oracle.com>
>>>> Date: Mon, 18 Jul 2022 18:12:26 +0000
>>>> Subject: [PATCH 2/2] Use new flag DECL_NOT_FLEXARRAY in __builtin_object_size
>>>> [PR101836]
>>>>
>>>> Use new flag DECL_NOT_FLEXARRAY to determine whether the trailing array
>>>> of a structure is flexible array member in __builtin_object_size.
>>>>
>>>> gcc/ChangeLog:
>>>>
>>>> PR tree-optimization/101836
>>>> * tree-object-size.cc (addr_object_size): Use array_at_struct_end_p
>>>> and DECL_NOT_FLEXARRAY to determine a flexible array member reference.
>>>>
>>>> gcc/testsuite/ChangeLog:
>>>>
>>>> PR tree-optimization/101836
>>>> * gcc.dg/pr101836.c: New test.
>>>> * gcc.dg/pr101836_1.c: New test.
>>>> * gcc.dg/pr101836_2.c: New test.
>>>> * gcc.dg/pr101836_3.c: New test.
>>>> * gcc.dg/pr101836_4.c: New test.
>>>> * gcc.dg/pr101836_5.c: New test.
>>>> * gcc.dg/strict-flex-array-2.c: New test.
>>>> * gcc.dg/strict-flex-array-3.c: New test.
>>>> ---
>>>> gcc/testsuite/gcc.dg/pr101836.c | 60 ++++++++++++++++++++++
>>>> gcc/testsuite/gcc.dg/pr101836_1.c | 60 ++++++++++++++++++++++
>>>> gcc/testsuite/gcc.dg/pr101836_2.c | 60 ++++++++++++++++++++++
>>>> gcc/testsuite/gcc.dg/pr101836_3.c | 60 ++++++++++++++++++++++
>>>> gcc/testsuite/gcc.dg/pr101836_4.c | 60 ++++++++++++++++++++++
>>>> gcc/testsuite/gcc.dg/pr101836_5.c | 60 ++++++++++++++++++++++
>>>> gcc/testsuite/gcc.dg/strict-flex-array-2.c | 60 ++++++++++++++++++++++
>>>> gcc/testsuite/gcc.dg/strict-flex-array-3.c | 60 ++++++++++++++++++++++
>>>> gcc/tree-object-size.cc | 18 +++----
>>>> 9 files changed, 489 insertions(+), 9 deletions(-)
>>>> create mode 100644 gcc/testsuite/gcc.dg/pr101836.c
>>>> create mode 100644 gcc/testsuite/gcc.dg/pr101836_1.c
>>>> create mode 100644 gcc/testsuite/gcc.dg/pr101836_2.c
>>>> create mode 100644 gcc/testsuite/gcc.dg/pr101836_3.c
>>>> create mode 100644 gcc/testsuite/gcc.dg/pr101836_4.c
>>>> create mode 100644 gcc/testsuite/gcc.dg/pr101836_5.c
>>>> create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-2.c
>>>> create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-3.c
>>>>
>>>> diff --git a/gcc/testsuite/gcc.dg/pr101836.c b/gcc/testsuite/gcc.dg/pr101836.c
>>>> new file mode 100644
>>>> index 00000000000..e5b4e5160a4
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.dg/pr101836.c
>>>> @@ -0,0 +1,60 @@
>>>> +/* -fstrict-flex-array is aliased with -ftrict-flex-array=3, which is the
>>>> + strictest, only [] is treated as flexible array. */
>>>> +/* PR tree-optimization/101836 */
>>>> +/* { dg-do run } */
>>>> +/* { dg-options "-O2 -fstrict-flex-array" } */
>>>> +
>>>> +#include <stdio.h>
>>>> +
>>>> +#define expect(p, _v) do { \
>>>> + size_t v = _v; \
>>>> + if (p == v) \
>>>> + printf("ok: %s == %zd\n", #p, p); \
>>>> + else \
>>>> + { \
>>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>>>> + __builtin_abort (); \
>>>> + } \
>>>> +} while (0);
>>>> +
>>>> +struct trailing_array_1 {
>>>> + int a;
>>>> + int b;
>>>> + int c[4];
>>>> +};
>>>> +
>>>> +struct trailing_array_2 {
>>>> + int a;
>>>> + int b;
>>>> + int c[1];
>>>> +};
>>>> +
>>>> +struct trailing_array_3 {
>>>> + int a;
>>>> + int b;
>>>> + int c[0];
>>>> +};
>>>> +struct trailing_array_4 {
>>>> + int a;
>>>> + int b;
>>>> + int c[];
>>>> +};
>>>> +
>>>> +void __attribute__((__noinline__)) stuff(
>>>> + struct trailing_array_1 *normal,
>>>> + struct trailing_array_2 *trailing_1,
>>>> + struct trailing_array_3 *trailing_0,
>>>> + struct trailing_array_4 *trailing_flex)
>>>> +{
>>>> + expect(__builtin_object_size(normal->c, 1), 16);
>>>> + expect(__builtin_object_size(trailing_1->c, 1), 4);
>>>> + expect(__builtin_object_size(trailing_0->c, 1), 0);
>>>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>>>> +}
>>>> +
>>>> +int main(int argc, char *argv[])
>>>> +{
>>>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>>>> +
>>>> + return 0;
>>>> +}
>>>> diff --git a/gcc/testsuite/gcc.dg/pr101836_1.c b/gcc/testsuite/gcc.dg/pr101836_1.c
>>>> new file mode 100644
>>>> index 00000000000..30ea20427a5
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.dg/pr101836_1.c
>>>> @@ -0,0 +1,60 @@
>>>> +/* -fstrict-flex-array=3 is the strictest, only [] is treated as
>>>> + flexible array. */
>>>> +/* PR tree-optimization/101836 */
>>>> +/* { dg-do run } */
>>>> +/* { dg-options "-O2 -fstrict-flex-array=3" } */
>>>> +
>>>> +#include <stdio.h>
>>>> +
>>>> +#define expect(p, _v) do { \
>>>> + size_t v = _v; \
>>>> + if (p == v) \
>>>> + printf("ok: %s == %zd\n", #p, p); \
>>>> + else \
>>>> + { \
>>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>>>> + __builtin_abort (); \
>>>> + } \
>>>> +} while (0);
>>>> +
>>>> +struct trailing_array_1 {
>>>> + int a;
>>>> + int b;
>>>> + int c[4];
>>>> +};
>>>> +
>>>> +struct trailing_array_2 {
>>>> + int a;
>>>> + int b;
>>>> + int c[1];
>>>> +};
>>>> +
>>>> +struct trailing_array_3 {
>>>> + int a;
>>>> + int b;
>>>> + int c[0];
>>>> +};
>>>> +struct trailing_array_4 {
>>>> + int a;
>>>> + int b;
>>>> + int c[];
>>>> +};
>>>> +
>>>> +void __attribute__((__noinline__)) stuff(
>>>> + struct trailing_array_1 *normal,
>>>> + struct trailing_array_2 *trailing_1,
>>>> + struct trailing_array_3 *trailing_0,
>>>> + struct trailing_array_4 *trailing_flex)
>>>> +{
>>>> + expect(__builtin_object_size(normal->c, 1), 16);
>>>> + expect(__builtin_object_size(trailing_1->c, 1), 4);
>>>> + expect(__builtin_object_size(trailing_0->c, 1), 0);
>>>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>>>> +}
>>>> +
>>>> +int main(int argc, char *argv[])
>>>> +{
>>>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>>>> +
>>>> + return 0;
>>>> +}
>>>> diff --git a/gcc/testsuite/gcc.dg/pr101836_2.c b/gcc/testsuite/gcc.dg/pr101836_2.c
>>>> new file mode 100644
>>>> index 00000000000..ebbe88f433c
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.dg/pr101836_2.c
>>>> @@ -0,0 +1,60 @@
>>>> +/* When -fstrict-flex-array=2, only [] and [0] are treated as flexiable
>>>> + arrays. */
>>>> +/* PR tree-optimization/101836 */
>>>> +/* { dg-do run } */
>>>> +/* { dg-options "-O2 -fstrict-flex-array=2" } */
>>>> +
>>>> +#include <stdio.h>
>>>> +
>>>> +#define expect(p, _v) do { \
>>>> + size_t v = _v; \
>>>> + if (p == v) \
>>>> + printf("ok: %s == %zd\n", #p, p); \
>>>> + else \
>>>> + { \
>>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>>>> + __builtin_abort (); \
>>>> + } \
>>>> +} while (0);
>>>> +
>>>> +struct trailing_array_1 {
>>>> + int a;
>>>> + int b;
>>>> + int c[4];
>>>> +};
>>>> +
>>>> +struct trailing_array_2 {
>>>> + int a;
>>>> + int b;
>>>> + int c[1];
>>>> +};
>>>> +
>>>> +struct trailing_array_3 {
>>>> + int a;
>>>> + int b;
>>>> + int c[0];
>>>> +};
>>>> +struct trailing_array_4 {
>>>> + int a;
>>>> + int b;
>>>> + int c[];
>>>> +};
>>>> +
>>>> +void __attribute__((__noinline__)) stuff(
>>>> + struct trailing_array_1 *normal,
>>>> + struct trailing_array_2 *trailing_1,
>>>> + struct trailing_array_3 *trailing_0,
>>>> + struct trailing_array_4 *trailing_flex)
>>>> +{
>>>> + expect(__builtin_object_size(normal->c, 1), 16);
>>>> + expect(__builtin_object_size(trailing_1->c, 1), 4);
>>>> + expect(__builtin_object_size(trailing_0->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>>>> +}
>>>> +
>>>> +int main(int argc, char *argv[])
>>>> +{
>>>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>>>> +
>>>> + return 0;
>>>> +}
>>>> diff --git a/gcc/testsuite/gcc.dg/pr101836_3.c b/gcc/testsuite/gcc.dg/pr101836_3.c
>>>> new file mode 100644
>>>> index 00000000000..d4ba0afe5bc
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.dg/pr101836_3.c
>>>> @@ -0,0 +1,60 @@
>>>> +/* When -fstrict-flex-array=1, [], [0], and [1] are treated as flexible
>>>> + arrays. */
>>>> +/* PR tree-optimization/101836 */
>>>> +/* { dg-do run } */
>>>> +/* { dg-options "-O2 -fstrict-flex-array=1" } */
>>>> +
>>>> +#include <stdio.h>
>>>> +
>>>> +#define expect(p, _v) do { \
>>>> + size_t v = _v; \
>>>> + if (p == v) \
>>>> + printf("ok: %s == %zd\n", #p, p); \
>>>> + else \
>>>> + { \
>>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>>>> + __builtin_abort (); \
>>>> + } \
>>>> +} while (0);
>>>> +
>>>> +struct trailing_array_1 {
>>>> + int a;
>>>> + int b;
>>>> + int c[4];
>>>> +};
>>>> +
>>>> +struct trailing_array_2 {
>>>> + int a;
>>>> + int b;
>>>> + int c[1];
>>>> +};
>>>> +
>>>> +struct trailing_array_3 {
>>>> + int a;
>>>> + int b;
>>>> + int c[0];
>>>> +};
>>>> +struct trailing_array_4 {
>>>> + int a;
>>>> + int b;
>>>> + int c[];
>>>> +};
>>>> +
>>>> +void __attribute__((__noinline__)) stuff(
>>>> + struct trailing_array_1 *normal,
>>>> + struct trailing_array_2 *trailing_1,
>>>> + struct trailing_array_3 *trailing_0,
>>>> + struct trailing_array_4 *trailing_flex)
>>>> +{
>>>> + expect(__builtin_object_size(normal->c, 1), 16);
>>>> + expect(__builtin_object_size(trailing_1->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_0->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>>>> +}
>>>> +
>>>> +int main(int argc, char *argv[])
>>>> +{
>>>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>>>> +
>>>> + return 0;
>>>> +}
>>>> diff --git a/gcc/testsuite/gcc.dg/pr101836_4.c b/gcc/testsuite/gcc.dg/pr101836_4.c
>>>> new file mode 100644
>>>> index 00000000000..b10d3ce312d
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.dg/pr101836_4.c
>>>> @@ -0,0 +1,60 @@
>>>> +/* when -fstrict-flex-array=0, all trailing arrays are treated as
>>>> + flexible arrays. */
>>>> +/* PR tree-optimization/101836 */
>>>> +/* { dg-do run } */
>>>> +/* { dg-options "-O2 -fstrict-flex-array=0" } */
>>>> +
>>>> +#include <stdio.h>
>>>> +
>>>> +#define expect(p, _v) do { \
>>>> + size_t v = _v; \
>>>> + if (p == v) \
>>>> + printf("ok: %s == %zd\n", #p, p); \
>>>> + else \
>>>> + { \
>>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>>>> + __builtin_abort (); \
>>>> + } \
>>>> +} while (0);
>>>> +
>>>> +struct trailing_array_1 {
>>>> + int a;
>>>> + int b;
>>>> + int c[4];
>>>> +};
>>>> +
>>>> +struct trailing_array_2 {
>>>> + int a;
>>>> + int b;
>>>> + int c[1];
>>>> +};
>>>> +
>>>> +struct trailing_array_3 {
>>>> + int a;
>>>> + int b;
>>>> + int c[0];
>>>> +};
>>>> +struct trailing_array_4 {
>>>> + int a;
>>>> + int b;
>>>> + int c[];
>>>> +};
>>>> +
>>>> +void __attribute__((__noinline__)) stuff(
>>>> + struct trailing_array_1 *normal,
>>>> + struct trailing_array_2 *trailing_1,
>>>> + struct trailing_array_3 *trailing_0,
>>>> + struct trailing_array_4 *trailing_flex)
>>>> +{
>>>> + expect(__builtin_object_size(normal->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_1->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_0->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>>>> +}
>>>> +
>>>> +int main(int argc, char *argv[])
>>>> +{
>>>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>>>> +
>>>> + return 0;
>>>> +}
>>>> diff --git a/gcc/testsuite/gcc.dg/pr101836_5.c b/gcc/testsuite/gcc.dg/pr101836_5.c
>>>> new file mode 100644
>>>> index 00000000000..2f6b5f7ae1f
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.dg/pr101836_5.c
>>>> @@ -0,0 +1,60 @@
>>>> +/* -fno-strict-flex-array is aliased to -fstrict-flex-array=0,
>>>> + all trailing arrays are treated as flexible array. */
>>>> +/* PR tree-optimization/101836 */
>>>> +/* { dg-do run } */
>>>> +/* { dg-options "-O2 -fno-strict-flex-array" } */
>>>> +
>>>> +#include <stdio.h>
>>>> +
>>>> +#define expect(p, _v) do { \
>>>> + size_t v = _v; \
>>>> + if (p == v) \
>>>> + printf("ok: %s == %zd\n", #p, p); \
>>>> + else \
>>>> + { \
>>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>>>> + __builtin_abort (); \
>>>> + } \
>>>> +} while (0);
>>>> +
>>>> +struct trailing_array_1 {
>>>> + int a;
>>>> + int b;
>>>> + int c[4];
>>>> +};
>>>> +
>>>> +struct trailing_array_2 {
>>>> + int a;
>>>> + int b;
>>>> + int c[1];
>>>> +};
>>>> +
>>>> +struct trailing_array_3 {
>>>> + int a;
>>>> + int b;
>>>> + int c[0];
>>>> +};
>>>> +struct trailing_array_4 {
>>>> + int a;
>>>> + int b;
>>>> + int c[];
>>>> +};
>>>> +
>>>> +void __attribute__((__noinline__)) stuff(
>>>> + struct trailing_array_1 *normal,
>>>> + struct trailing_array_2 *trailing_1,
>>>> + struct trailing_array_3 *trailing_0,
>>>> + struct trailing_array_4 *trailing_flex)
>>>> +{
>>>> + expect(__builtin_object_size(normal->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_1->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_0->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>>>> +}
>>>> +
>>>> +int main(int argc, char *argv[])
>>>> +{
>>>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>>>> +
>>>> + return 0;
>>>> +}
>>>> diff --git a/gcc/testsuite/gcc.dg/strict-flex-array-2.c b/gcc/testsuite/gcc.dg/strict-flex-array-2.c
>>>> new file mode 100644
>>>> index 00000000000..326ddcfeda5
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-2.c
>>>> @@ -0,0 +1,60 @@
>>>> +/* test the combination of attribute strict_flex_array and option
>>>> + -fstrict-flex-array: when both attribute and option specified,
>>>> + attribute will have higher priority. */
>>>> +/* { dg-do run } */
>>>> +/* { dg-options "-O2 -fstrict-flex-array=3" } */
>>>> +
>>>> +#include <stdio.h>
>>>> +
>>>> +#define expect(p, _v) do { \
>>>> + size_t v = _v; \
>>>> + if (p == v) \
>>>> + printf("ok: %s == %zd\n", #p, p); \
>>>> + else \
>>>> + { \
>>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>>>> + __builtin_abort (); \
>>>> + } \
>>>> +} while (0);
>>>> +
>>>> +struct trailing_array_1 {
>>>> + int a;
>>>> + int b;
>>>> + int c[4] __attribute__ ((strict_flex_array (0)));
>>>> +};
>>>> +
>>>> +struct trailing_array_2 {
>>>> + int a;
>>>> + int b;
>>>> + int c[1] __attribute__ ((strict_flex_array (1)));
>>>> +};
>>>> +
>>>> +struct trailing_array_3 {
>>>> + int a;
>>>> + int b;
>>>> + int c[0] __attribute__ ((strict_flex_array (2)));
>>>> +};
>>>> +struct trailing_array_4 {
>>>> + int a;
>>>> + int b;
>>>> + int c[];
>>>> +};
>>>> +
>>>> +void __attribute__((__noinline__)) stuff(
>>>> + struct trailing_array_1 *normal,
>>>> + struct trailing_array_2 *trailing_1,
>>>> + struct trailing_array_3 *trailing_0,
>>>> + struct trailing_array_4 *trailing_flex)
>>>> +{
>>>> + expect(__builtin_object_size(normal->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_1->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_0->c, 1), -1);
>>>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>>>> +}
>>>> +
>>>> +int main(int argc, char *argv[])
>>>> +{
>>>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>>>> +
>>>> + return 0;
>>>> +}
>>>> diff --git a/gcc/testsuite/gcc.dg/strict-flex-array-3.c b/gcc/testsuite/gcc.dg/strict-flex-array-3.c
>>>> new file mode 100644
>>>> index 00000000000..990c5bb6223
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-3.c
>>>> @@ -0,0 +1,60 @@
>>>> +/* test the combination of attribute strict_flex_array and option
>>>> + -fstrict-flex-array: when both attribute and option specified,
>>>> + attribute will have higher priority. */
>>>> +/* { dg-do run } */
>>>> +/* { dg-options "-O2 -fstrict-flex-array=0" } */
>>>> +
>>>> +#include <stdio.h>
>>>> +
>>>> +#define expect(p, _v) do { \
>>>> + size_t v = _v; \
>>>> + if (p == v) \
>>>> + printf("ok: %s == %zd\n", #p, p); \
>>>> + else \
>>>> + { \
>>>> + printf("WAT: %s == %zd (expected %zd)\n", #p, p, v); \
>>>> + __builtin_abort (); \
>>>> + } \
>>>> +} while (0);
>>>> +
>>>> +struct trailing_array_1 {
>>>> + int a;
>>>> + int b;
>>>> + int c[4] __attribute__ ((strict_flex_array (1)));
>>>> +};
>>>> +
>>>> +struct trailing_array_2 {
>>>> + int a;
>>>> + int b;
>>>> + int c[1] __attribute__ ((strict_flex_array (2)));
>>>> +};
>>>> +
>>>> +struct trailing_array_3 {
>>>> + int a;
>>>> + int b;
>>>> + int c[0] __attribute__ ((strict_flex_array (3)));
>>>> +};
>>>> +struct trailing_array_4 {
>>>> + int a;
>>>> + int b;
>>>> + int c[];
>>>> +};
>>>> +
>>>> +void __attribute__((__noinline__)) stuff(
>>>> + struct trailing_array_1 *normal,
>>>> + struct trailing_array_2 *trailing_1,
>>>> + struct trailing_array_3 *trailing_0,
>>>> + struct trailing_array_4 *trailing_flex)
>>>> +{
>>>> + expect(__builtin_object_size(normal->c, 1), 16);
>>>> + expect(__builtin_object_size(trailing_1->c, 1), 4);
>>>> + expect(__builtin_object_size(trailing_0->c, 1), 0);
>>>> + expect(__builtin_object_size(trailing_flex->c, 1), -1);
>>>> +}
>>>> +
>>>> +int main(int argc, char *argv[])
>>>> +{
>>>> + stuff((void *)argv[0], (void *)argv[0], (void *)argv[0], (void *)argv[0]);
>>>> +
>>>> + return 0;
>>>> +}
>>>> diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
>>>> index 4eb454a4a33..90710ecba72 100644
>>>> --- a/gcc/tree-object-size.cc
>>>> +++ b/gcc/tree-object-size.cc
>>>> @@ -604,9 +604,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
>>>> else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF)
>>>> {
>>>> tree v = var;
>>>> - /* For &X->fld, compute object size only if fld isn't the last
>>>> - field, as struct { int i; char c[1]; } is often used instead
>>>> - of flexible array member. */
>>>> + bool is_flexible_array_mem_ref = false;
>>>> + /* For &X->fld, compute object size if fld isn't a flexible array
>>>> + member. */
>>>> while (v && v != pt_var)
>>>> switch (TREE_CODE (v))
>>>> {
>>>> @@ -633,6 +633,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
>>>> v = NULL_TREE;
>>>> break;
>>>> }
>>>> + is_flexible_array_mem_ref
>>>> + = array_at_struct_end_p (v)
>>>> + && !DECL_NOT_FLEXARRAY (TREE_OPERAND (v, 1));
>>>
>>> As said in the review for the first patch array_at_struct_end_p should
>>> check DECL_NOT_FLEXARRAY.
>> Okay.
>>
>> Then, should we change the name of “array_at_struct_end_p” to a more
>> descriptive name, for example,”flexible_array_member_p”? Otherwise, It’s
>> really confusing.
>
> It has been that way since forever, so please don't (at least not as
> part of this series).
Okay, I will keep the name as it in this set of patches.
(However, I do think that we should change the name of this routine, it’s really confusing…)
Qing
>
>>
>>
>>>
>>> OK with removing the extra check here.
>>
>> Okay.
>>
>>
>> thanks.
>>
>> Qing
>>>
>>>> while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
>>>> if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
>>>> != UNION_TYPE
>>>> @@ -645,12 +648,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
>>>> && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
>>>> == RECORD_TYPE)
>>>> {
>>>> - tree fld_chain = DECL_CHAIN (TREE_OPERAND (v, 1));
>>>> - for (; fld_chain; fld_chain = DECL_CHAIN (fld_chain))
>>>> - if (TREE_CODE (fld_chain) == FIELD_DECL)
>>>> - break;
>>>> -
>>>> - if (fld_chain)
>>>> + /* compute object size only if v is not a
>>>> + flexible array member. */
>>>> + if (!is_flexible_array_mem_ref)
>>>> {
>>>> v = NULL_TREE;
>>>> break;
>>>>
>>>
>>> --
>>> Richard Biener <rguenther@suse.de>
>>> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
>>> Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
>>> HRB 36809 (AG Nuernberg)
>>
>>
>
> --
> Richard Biener <rguenther@suse.de>
> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
> Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
> HRB 36809 (AG Nuernberg)
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [GCC13][Patch][V2][2/2]Add a new option -fstrict-flex-array[=n] and attribute strict_flex_array(n) and use it in PR101836
2022-07-19 14:11 [GCC13][Patch][V2][2/2]Add a new option -fstrict-flex-array[=n] and attribute strict_flex_array(n) and use it in PR101836 Qing Zhao
2022-07-28 7:28 ` Richard Biener
@ 2022-08-02 15:30 ` Kees Cook
2022-08-02 15:41 ` Qing Zhao
1 sibling, 1 reply; 7+ messages in thread
From: Kees Cook @ 2022-08-02 15:30 UTC (permalink / raw)
To: Qing Zhao
Cc: gcc-patches, jakub Jelinek, richard Biener, martin Sebor, joseph
On Tue, Jul 19, 2022 at 02:11:19PM +0000, Qing Zhao wrote:
> From a09f39ded462611286a44d9e8273de8342673ba2 Mon Sep 17 00:00:00 2001
> From: Qing Zhao <qing.zhao@oracle.com>
> Date: Mon, 18 Jul 2022 18:12:26 +0000
> Subject: [PATCH 2/2] Use new flag DECL_NOT_FLEXARRAY in __builtin_object_size
> [PR101836]
>
> Use new flag DECL_NOT_FLEXARRAY to determine whether the trailing array
> of a structure is flexible array member in __builtin_object_size.
FWIW, with these patches I've done builds of the Linux kernel using
the ...=3 level, and things are looking correct on our end. (There are,
as expected, many places in Linux that need to be fixed, and that work
is on-going, guided by this option's results.)
-Kees
--
Kees Cook
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [GCC13][Patch][V2][2/2]Add a new option -fstrict-flex-array[=n] and attribute strict_flex_array(n) and use it in PR101836
2022-08-02 15:30 ` Kees Cook
@ 2022-08-02 15:41 ` Qing Zhao
0 siblings, 0 replies; 7+ messages in thread
From: Qing Zhao @ 2022-08-02 15:41 UTC (permalink / raw)
To: Kees Cook
Cc: gcc-patches, jakub Jelinek, richard Biener, martin Sebor, joseph
Thanks a lot for your testing on Linux Kernel.
Will work on the version 3 of this patch soon.
Qing
> On Aug 2, 2022, at 11:30 AM, Kees Cook <keescook@chromium.org> wrote:
>
> On Tue, Jul 19, 2022 at 02:11:19PM +0000, Qing Zhao wrote:
>> From a09f39ded462611286a44d9e8273de8342673ba2 Mon Sep 17 00:00:00 2001
>> From: Qing Zhao <qing.zhao@oracle.com>
>> Date: Mon, 18 Jul 2022 18:12:26 +0000
>> Subject: [PATCH 2/2] Use new flag DECL_NOT_FLEXARRAY in __builtin_object_size
>> [PR101836]
>>
>> Use new flag DECL_NOT_FLEXARRAY to determine whether the trailing array
>> of a structure is flexible array member in __builtin_object_size.
>
> FWIW, with these patches I've done builds of the Linux kernel using
> the ...=3 level, and things are looking correct on our end. (There are,
> as expected, many places in Linux that need to be fixed, and that work
> is on-going, guided by this option's results.)
>
> -Kees
>
> --
> Kees Cook
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2022-08-02 15:41 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-07-19 14:11 [GCC13][Patch][V2][2/2]Add a new option -fstrict-flex-array[=n] and attribute strict_flex_array(n) and use it in PR101836 Qing Zhao
2022-07-28 7:28 ` Richard Biener
2022-07-29 14:23 ` Qing Zhao
2022-08-01 7:13 ` Richard Biener
2022-08-01 14:14 ` Qing Zhao
2022-08-02 15:30 ` Kees Cook
2022-08-02 15:41 ` Qing Zhao
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