[[GCC13,V3] 2/2] Use array_at_struct_end_p in __builtin_object_size [PR101836]
Commit Message
Use array_at_struct_end_p 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
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-5.c: New test.
* gcc.dg/strict-flex-array-6.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-5.c | 60 ++++++++++++++++++++++
gcc/testsuite/gcc.dg/strict-flex-array-6.c | 60 ++++++++++++++++++++++
gcc/tree-object-size.cc | 16 +++---
9 files changed, 487 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-5.c
create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-6.c
Comments
On Wed, 17 Aug 2022, Qing Zhao wrote:
> Use array_at_struct_end_p to determine whether the trailing array
> of a structure is flexible array member in __builtin_object_size.
With the discussion about what array_at_struct_end_p actually computes,
is this now the correct utility for __builtin_object_size or should
it use a stricter variant?
> gcc/ChangeLog:
>
> PR tree-optimization/101836
> * tree-object-size.cc (addr_object_size): Use array_at_struct_end_p
> 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-5.c: New test.
> * gcc.dg/strict-flex-array-6.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-5.c | 60 ++++++++++++++++++++++
> gcc/testsuite/gcc.dg/strict-flex-array-6.c | 60 ++++++++++++++++++++++
> gcc/tree-object-size.cc | 16 +++---
> 9 files changed, 487 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-5.c
> create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-6.c
>
> diff --git a/gcc/testsuite/gcc.dg/pr101836.c b/gcc/testsuite/gcc.dg/pr101836.c
> new file mode 100644
> index 000000000000..efad02cfe899
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836.c
> @@ -0,0 +1,60 @@
> +/* -fstrict-flex-arrays is aliased with -ftrict-flex-arrays=3, which is the
> + strictest, only [] is treated as flexible array. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-arrays" } */
> +
> +#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 000000000000..e2931ce1012e
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836_1.c
> @@ -0,0 +1,60 @@
> +/* -fstrict-flex-arrays=3 is the strictest, only [] is treated as
> + flexible array. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-arrays=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 000000000000..78974187721f
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836_2.c
> @@ -0,0 +1,60 @@
> +/* When -fstrict-flex-arrays=2, only [] and [0] are treated as flexiable
> + arrays. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-arrays=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 000000000000..0e69388e81fb
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836_3.c
> @@ -0,0 +1,60 @@
> +/* When -fstrict-flex-arrays=1, [], [0], and [1] are treated as flexible
> + arrays. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-arrays=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 000000000000..e0025aa9a7b5
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836_4.c
> @@ -0,0 +1,60 @@
> +/* when -fstrict-flex-arrays=0, all trailing arrays are treated as
> + flexible arrays. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-arrays=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 000000000000..0ad8bbf693ce
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101836_5.c
> @@ -0,0 +1,60 @@
> +/* -fno-strict-flex-arrays is aliased to -fstrict-flex-arrays=0,
> + all trailing arrays are treated as flexible array. */
> +/* PR tree-optimization/101836 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fno-strict-flex-arrays" } */
> +
> +#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-5.c b/gcc/testsuite/gcc.dg/strict-flex-array-5.c
> new file mode 100644
> index 000000000000..e474b9ec43fa
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-5.c
> @@ -0,0 +1,60 @@
> +/* test the combination of attribute strict_flex_arrays and option
> + -fstrict-flex-arrays: when both attribute and option specified,
> + attribute will have higher priority. */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-arrays=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_arrays (0)));
> +};
> +
> +struct trailing_array_2 {
> + int a;
> + int b;
> + int c[1] __attribute__ ((strict_flex_arrays (1)));
> +};
> +
> +struct trailing_array_3 {
> + int a;
> + int b;
> + int c[0] __attribute__ ((strict_flex_arrays (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-6.c b/gcc/testsuite/gcc.dg/strict-flex-array-6.c
> new file mode 100644
> index 000000000000..b45e7b32f6d1
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-6.c
> @@ -0,0 +1,60 @@
> +/* test the combination of attribute strict_flex_arrays and option
> + -fstrict-flex-arrays: when both attribute and option specified,
> + attribute will have higher priority. */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fstrict-flex-arrays=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_arrays (1)));
> +};
> +
> +struct trailing_array_2 {
> + int a;
> + int b;
> + int c[1] __attribute__ ((strict_flex_arrays (2)));
> +};
> +
> +struct trailing_array_3 {
> + int a;
> + int b;
> + int c[0] __attribute__ ((strict_flex_arrays (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 4eb454a4a33b..1f04cb80fd0a 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. */
> + /* For &X->fld, compute object size if fld isn't a flexible array
> + member. */
> + bool is_flexible_array_mem_ref = false;
> while (v && v != pt_var)
> switch (TREE_CODE (v))
> {
> @@ -633,6 +633,7 @@ 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);
> while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
> if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
> != UNION_TYPE
> @@ -645,12 +646,9 @@ 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;
>
> On Aug 26, 2022, at 4:49 AM, Richard Biener <rguenther@suse.de> wrote:
>
> On Wed, 17 Aug 2022, Qing Zhao wrote:
>
>> Use array_at_struct_end_p to determine whether the trailing array
>> of a structure is flexible array member in __builtin_object_size.
>
> With the discussion about what array_at_struct_end_p actually computes,
> is this now the correct utility for __builtin_object_size or should
> it use a stricter variant?
My understanding is, -fstrict-flex-arrays should control all the GCC analysis consistently, including __bultin_object_size.
For a standard conforming application, use -fstrict-flex-arrays=3 for the most efficient code.
Kees, is it okay for Linux Kernel to add -fstrict-flex-arrays in order to enable FORTIFY_SOURCE work better for regular trailing arrays?
Thanks.
Qing
>
>> gcc/ChangeLog:
>>
>> PR tree-optimization/101836
>> * tree-object-size.cc (addr_object_size): Use array_at_struct_end_p
>> 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-5.c: New test.
>> * gcc.dg/strict-flex-array-6.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-5.c | 60 ++++++++++++++++++++++
>> gcc/testsuite/gcc.dg/strict-flex-array-6.c | 60 ++++++++++++++++++++++
>> gcc/tree-object-size.cc | 16 +++---
>> 9 files changed, 487 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-5.c
>> create mode 100644 gcc/testsuite/gcc.dg/strict-flex-array-6.c
>>
>> diff --git a/gcc/testsuite/gcc.dg/pr101836.c b/gcc/testsuite/gcc.dg/pr101836.c
>> new file mode 100644
>> index 000000000000..efad02cfe899
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836.c
>> @@ -0,0 +1,60 @@
>> +/* -fstrict-flex-arrays is aliased with -ftrict-flex-arrays=3, which is the
>> + strictest, only [] is treated as flexible array. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-arrays" } */
>> +
>> +#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 000000000000..e2931ce1012e
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836_1.c
>> @@ -0,0 +1,60 @@
>> +/* -fstrict-flex-arrays=3 is the strictest, only [] is treated as
>> + flexible array. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-arrays=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 000000000000..78974187721f
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836_2.c
>> @@ -0,0 +1,60 @@
>> +/* When -fstrict-flex-arrays=2, only [] and [0] are treated as flexiable
>> + arrays. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-arrays=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 000000000000..0e69388e81fb
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836_3.c
>> @@ -0,0 +1,60 @@
>> +/* When -fstrict-flex-arrays=1, [], [0], and [1] are treated as flexible
>> + arrays. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-arrays=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 000000000000..e0025aa9a7b5
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836_4.c
>> @@ -0,0 +1,60 @@
>> +/* when -fstrict-flex-arrays=0, all trailing arrays are treated as
>> + flexible arrays. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-arrays=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 000000000000..0ad8bbf693ce
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/pr101836_5.c
>> @@ -0,0 +1,60 @@
>> +/* -fno-strict-flex-arrays is aliased to -fstrict-flex-arrays=0,
>> + all trailing arrays are treated as flexible array. */
>> +/* PR tree-optimization/101836 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fno-strict-flex-arrays" } */
>> +
>> +#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-5.c b/gcc/testsuite/gcc.dg/strict-flex-array-5.c
>> new file mode 100644
>> index 000000000000..e474b9ec43fa
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-5.c
>> @@ -0,0 +1,60 @@
>> +/* test the combination of attribute strict_flex_arrays and option
>> + -fstrict-flex-arrays: when both attribute and option specified,
>> + attribute will have higher priority. */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-arrays=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_arrays (0)));
>> +};
>> +
>> +struct trailing_array_2 {
>> + int a;
>> + int b;
>> + int c[1] __attribute__ ((strict_flex_arrays (1)));
>> +};
>> +
>> +struct trailing_array_3 {
>> + int a;
>> + int b;
>> + int c[0] __attribute__ ((strict_flex_arrays (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-6.c b/gcc/testsuite/gcc.dg/strict-flex-array-6.c
>> new file mode 100644
>> index 000000000000..b45e7b32f6d1
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/strict-flex-array-6.c
>> @@ -0,0 +1,60 @@
>> +/* test the combination of attribute strict_flex_arrays and option
>> + -fstrict-flex-arrays: when both attribute and option specified,
>> + attribute will have higher priority. */
>> +/* { dg-do run } */
>> +/* { dg-options "-O2 -fstrict-flex-arrays=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_arrays (1)));
>> +};
>> +
>> +struct trailing_array_2 {
>> + int a;
>> + int b;
>> + int c[1] __attribute__ ((strict_flex_arrays (2)));
>> +};
>> +
>> +struct trailing_array_3 {
>> + int a;
>> + int b;
>> + int c[0] __attribute__ ((strict_flex_arrays (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 4eb454a4a33b..1f04cb80fd0a 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. */
>> + /* For &X->fld, compute object size if fld isn't a flexible array
>> + member. */
>> + bool is_flexible_array_mem_ref = false;
>> while (v && v != pt_var)
>> switch (TREE_CODE (v))
>> {
>> @@ -633,6 +633,7 @@ 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);
>> while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
>> if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
>> != UNION_TYPE
>> @@ -645,12 +646,9 @@ 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)
new file mode 100644
@@ -0,0 +1,60 @@
+/* -fstrict-flex-arrays is aliased with -ftrict-flex-arrays=3, which is the
+ strictest, only [] is treated as flexible array. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-arrays" } */
+
+#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;
+}
new file mode 100644
@@ -0,0 +1,60 @@
+/* -fstrict-flex-arrays=3 is the strictest, only [] is treated as
+ flexible array. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-arrays=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;
+}
new file mode 100644
@@ -0,0 +1,60 @@
+/* When -fstrict-flex-arrays=2, only [] and [0] are treated as flexiable
+ arrays. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-arrays=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;
+}
new file mode 100644
@@ -0,0 +1,60 @@
+/* When -fstrict-flex-arrays=1, [], [0], and [1] are treated as flexible
+ arrays. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-arrays=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;
+}
new file mode 100644
@@ -0,0 +1,60 @@
+/* when -fstrict-flex-arrays=0, all trailing arrays are treated as
+ flexible arrays. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-arrays=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;
+}
new file mode 100644
@@ -0,0 +1,60 @@
+/* -fno-strict-flex-arrays is aliased to -fstrict-flex-arrays=0,
+ all trailing arrays are treated as flexible array. */
+/* PR tree-optimization/101836 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fno-strict-flex-arrays" } */
+
+#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;
+}
new file mode 100644
@@ -0,0 +1,60 @@
+/* test the combination of attribute strict_flex_arrays and option
+ -fstrict-flex-arrays: when both attribute and option specified,
+ attribute will have higher priority. */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-arrays=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_arrays (0)));
+};
+
+struct trailing_array_2 {
+ int a;
+ int b;
+ int c[1] __attribute__ ((strict_flex_arrays (1)));
+};
+
+struct trailing_array_3 {
+ int a;
+ int b;
+ int c[0] __attribute__ ((strict_flex_arrays (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;
+}
new file mode 100644
@@ -0,0 +1,60 @@
+/* test the combination of attribute strict_flex_arrays and option
+ -fstrict-flex-arrays: when both attribute and option specified,
+ attribute will have higher priority. */
+/* { dg-do run } */
+/* { dg-options "-O2 -fstrict-flex-arrays=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_arrays (1)));
+};
+
+struct trailing_array_2 {
+ int a;
+ int b;
+ int c[1] __attribute__ ((strict_flex_arrays (2)));
+};
+
+struct trailing_array_3 {
+ int a;
+ int b;
+ int c[0] __attribute__ ((strict_flex_arrays (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;
+}
@@ -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. */
+ /* For &X->fld, compute object size if fld isn't a flexible array
+ member. */
+ bool is_flexible_array_mem_ref = false;
while (v && v != pt_var)
switch (TREE_CODE (v))
{
@@ -633,6 +633,7 @@ 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);
while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
!= UNION_TYPE
@@ -645,12 +646,9 @@ 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;