From: Siddhesh Poyarekar <siddhesh@gotplt.org>
To: gcc-patches@gcc.gnu.org
Cc: jakub@redhat.com
Subject: [PATCH 2/2] tree-object-size: More consistent behaviour with flex arrays
Date: Wed, 21 Dec 2022 17:25:54 -0500 [thread overview]
Message-ID: <20221221222554.4141678-3-siddhesh@gotplt.org> (raw)
In-Reply-To: <20221221222554.4141678-1-siddhesh@gotplt.org>
The tree object size pass tries to fail when it detects a flex array in
the struct, but it ends up doing the right thing only when the flex
array is in the outermost struct. For nested cases (such as arrays
nested in a union or an inner struct), it ends up taking whatever value
the flex array is declared with, using zero for the standard flex array,
i.e. [].
Rework subobject size computation to make it more consistent across the
board, honoring -fstrict-flex-arrays. With this change, any array at
the end of the struct will end up causing __bos to use the allocated
value of the outer object, bailing out in the maximum case when it can't
find it. In the minimum case, it will return the subscript value or the
allocated value of the outer object, whichever is larger.
gcc/ChangeLog:
PR tree-optimization/107952
* tree-object-size.cc (size_from_objects): New function.
(addr_object_size): Call it. Fully rely on
array_ref_flexible_size_p call to determine flex array.
gcc/testsuite/ChangeLog:
PR tree-optimization/107952
* g++.dg/ext/builtin-object-size1.C (test1, test6, test7,
test8): Adjust expected result for object size type 3 and 1.
* g++.dg/ext/builtin-object-size2.C (test1, test6, test7,
test8): Likewise.
* gcc.dg/builtin-object-size-13.c (main): Likewise.
* gcc.dg/builtin-object-size-6.c (test1, test6, test7, test8):
Likewise.
* gcc.dg/builtin-object-size-8.c (main): Likewise.
* gcc.dg/builtin-object-size-flex-common.h: Common code for new
tests.
* gcc.dg/builtin-object-size-flex-nested-struct-nonzero.c: New
test.
* gcc.dg/builtin-object-size-flex-nested-struct-zero.c: New
test.
* gcc.dg/builtin-object-size-flex-nested-struct.c: New test.
* gcc.dg/builtin-object-size-flex-nested-union-nonzero.c: New
test.
* gcc.dg/builtin-object-size-flex-nested-union-zero.c: New test.
* gcc.dg/builtin-object-size-flex-nested-union.c: New test.
* gcc.dg/builtin-object-size-flex-nonzero.c: New test.
* gcc.dg/builtin-object-size-flex-zero.c: New test.
* gcc.dg/builtin-object-size-flex.c: New test.
Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>
---
.../g++.dg/ext/builtin-object-size1.C | 10 +-
.../g++.dg/ext/builtin-object-size2.C | 10 +-
gcc/testsuite/gcc.dg/builtin-object-size-13.c | 4 +-
gcc/testsuite/gcc.dg/builtin-object-size-6.c | 10 +-
gcc/testsuite/gcc.dg/builtin-object-size-8.c | 4 +-
.../gcc.dg/builtin-object-size-flex-common.h | 90 +++++++++++
...n-object-size-flex-nested-struct-nonzero.c | 6 +
...ltin-object-size-flex-nested-struct-zero.c | 6 +
.../builtin-object-size-flex-nested-struct.c | 22 +++
...in-object-size-flex-nested-union-nonzero.c | 6 +
...iltin-object-size-flex-nested-union-zero.c | 6 +
.../builtin-object-size-flex-nested-union.c | 28 ++++
.../gcc.dg/builtin-object-size-flex-nonzero.c | 6 +
.../gcc.dg/builtin-object-size-flex-zero.c | 6 +
.../gcc.dg/builtin-object-size-flex.c | 18 +++
gcc/tree-object-size.cc | 150 ++++++------------
16 files changed, 265 insertions(+), 117 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-flex-common.h
create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct-nonzero.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct-zero.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union-nonzero.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union-zero.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-flex-nonzero.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-flex-zero.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-flex.c
diff --git a/gcc/testsuite/g++.dg/ext/builtin-object-size1.C b/gcc/testsuite/g++.dg/ext/builtin-object-size1.C
index 165b415683b..5b863637123 100644
--- a/gcc/testsuite/g++.dg/ext/builtin-object-size1.C
+++ b/gcc/testsuite/g++.dg/ext/builtin-object-size1.C
@@ -103,7 +103,7 @@ test1 (A *p)
FAIL ();
if (__builtin_object_size (&p->b, 3) != sizeof (p->b))
FAIL ();
- if (__builtin_object_size (&p->c, 3) != 0)
+ if (__builtin_object_size (&p->c, 3) != 10)
FAIL ();
c = p->a;
if (__builtin_object_size (c, 3) != sizeof (p->a))
@@ -118,7 +118,7 @@ test1 (A *p)
if (__builtin_object_size (c, 3) != sizeof (p->b))
FAIL ();
c = (char *) &p->c;
- if (__builtin_object_size (c, 3) != 0)
+ if (__builtin_object_size (c, 3) != 10)
FAIL ();
}
@@ -344,7 +344,7 @@ test6 (struct D *d)
{
if (__builtin_object_size (&d->j.a[3], 0) != (size_t) -1)
FAIL ();
- if (__builtin_object_size (&d->j.a[3], 1) != sizeof (d->j.a) - 3)
+ if (__builtin_object_size (&d->j.a[3], 1) != (size_t) -1)
FAIL ();
if (__builtin_object_size (&d->j.a[3], 2) != 0)
FAIL ();
@@ -380,7 +380,7 @@ test7 (struct E *e)
FAIL ();
if (__builtin_object_size ((char *) &e->j[0], 2) != 0)
FAIL ();
- if (__builtin_object_size ((char *) &e->j[0], 3) != 0)
+ if (__builtin_object_size ((char *) &e->j[0], 3) != sizeof (e->j))
FAIL ();
}
@@ -404,7 +404,7 @@ test8 (union F *f)
FAIL ();
if (__builtin_object_size (&f->d.c[3], 2) != 0)
FAIL ();
- if (__builtin_object_size (&f->d.c[3], 3) != 0)
+ if (__builtin_object_size (&f->d.c[3], 3) != sizeof (f->d.c) - 3)
FAIL ();
}
diff --git a/gcc/testsuite/g++.dg/ext/builtin-object-size2.C b/gcc/testsuite/g++.dg/ext/builtin-object-size2.C
index c5dbd96193c..665dad886d4 100644
--- a/gcc/testsuite/g++.dg/ext/builtin-object-size2.C
+++ b/gcc/testsuite/g++.dg/ext/builtin-object-size2.C
@@ -106,7 +106,7 @@ test1 (A *p)
FAIL ();
if (__builtin_object_size (&p->b, 3) != sizeof (p->b))
FAIL ();
- if (__builtin_object_size (&p->c, 3) != 0)
+ if (__builtin_object_size (&p->c, 3) != 10)
FAIL ();
c = p->a;
if (__builtin_object_size (c, 3) != sizeof (p->a))
@@ -121,7 +121,7 @@ test1 (A *p)
if (__builtin_object_size (c, 3) != sizeof (p->b))
FAIL ();
c = (char *) &p->c;
- if (__builtin_object_size (c, 3) != 0)
+ if (__builtin_object_size (c, 3) != 10)
FAIL ();
}
@@ -347,7 +347,7 @@ test6 (struct D *d)
{
if (__builtin_object_size (&d->j.a[3], 0) != (size_t) -1)
FAIL ();
- if (__builtin_object_size (&d->j.a[3], 1) != sizeof (d->j.a) - 3)
+ if (__builtin_object_size (&d->j.a[3], 1) != (size_t) -1)
FAIL ();
if (__builtin_object_size (&d->j.a[3], 2) != 0)
FAIL ();
@@ -383,7 +383,7 @@ test7 (struct E *e)
FAIL ();
if (__builtin_object_size ((char *) &e->j[0], 2) != 0)
FAIL ();
- if (__builtin_object_size ((char *) &e->j[0], 3) != 0)
+ if (__builtin_object_size ((char *) &e->j[0], 3) != sizeof (e->j))
FAIL ();
}
@@ -407,7 +407,7 @@ test8 (union F *f)
FAIL ();
if (__builtin_object_size (&f->d.c[3], 2) != 0)
FAIL ();
- if (__builtin_object_size (&f->d.c[3], 3) != 0)
+ if (__builtin_object_size (&f->d.c[3], 3) != sizeof (f->d.c) - 3)
FAIL ();
}
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-13.c b/gcc/testsuite/gcc.dg/builtin-object-size-13.c
index c7d58c941d4..6429dcaf426 100644
--- a/gcc/testsuite/gcc.dg/builtin-object-size-13.c
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-13.c
@@ -332,9 +332,9 @@ main (void)
o2 = __builtin_offsetof (struct H, h2.e1.c2);
h1 = malloc (s);
h2 = malloc (o2 + 212);
- TA (h1->h2.e1.c2.a2, s - o2, sizeof (h1->h2.e1.c2.a2));
+ TA (h1->h2.e1.c2.a2, s - o2, s - o2);
s = o2 + 212;
- TA (h2->h2.e1.c2.a2, s - o2, sizeof (h2->h2.e1.c2.a2));
+ TA (h2->h2.e1.c2.a2, s - o2, s - o2);
free (h2);
free (h1);
s = sizeof (struct H);
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-6.c b/gcc/testsuite/gcc.dg/builtin-object-size-6.c
index 4ce05184143..1ae608d456b 100644
--- a/gcc/testsuite/gcc.dg/builtin-object-size-6.c
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-6.c
@@ -103,7 +103,7 @@ test1 (struct A *p)
FAIL ();
if (__builtin_object_size (&p->b, 3) != sizeof (p->b))
FAIL ();
- if (__builtin_object_size (&p->c, 3) != 0)
+ if (__builtin_object_size (&p->c, 3) != 10)
FAIL ();
c = p->a;
if (__builtin_object_size (c, 3) != sizeof (p->a))
@@ -118,7 +118,7 @@ test1 (struct A *p)
if (__builtin_object_size (c, 3) != sizeof (p->b))
FAIL ();
c = (char *) &p->c;
- if (__builtin_object_size (c, 3) != 0)
+ if (__builtin_object_size (c, 3) != 10)
FAIL ();
}
@@ -344,7 +344,7 @@ test6 (struct D *d)
{
if (__builtin_object_size (&d->j.a[3], 0) != (size_t) -1)
FAIL ();
- if (__builtin_object_size (&d->j.a[3], 1) != sizeof (d->j.a) - 3)
+ if (__builtin_object_size (&d->j.a[3], 1) != -1)
FAIL ();
if (__builtin_object_size (&d->j.a[3], 2) != 0)
FAIL ();
@@ -380,7 +380,7 @@ test7 (struct E *e)
FAIL ();
if (__builtin_object_size ((char *) &e->j[0], 2) != 0)
FAIL ();
- if (__builtin_object_size ((char *) &e->j[0], 3) != 0)
+ if (__builtin_object_size ((char *) &e->j[0], 3) != sizeof (e->j))
FAIL ();
}
@@ -404,7 +404,7 @@ test8 (union F *f)
FAIL ();
if (__builtin_object_size (&f->d.c[3], 2) != 0)
FAIL ();
- if (__builtin_object_size (&f->d.c[3], 3) != 0)
+ if (__builtin_object_size (&f->d.c[3], 3) != 7)
FAIL ();
}
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-8.c b/gcc/testsuite/gcc.dg/builtin-object-size-8.c
index f67902e29f0..184769f1bd8 100644
--- a/gcc/testsuite/gcc.dg/builtin-object-size-8.c
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-8.c
@@ -186,13 +186,13 @@ main (void)
TS (h1->h1, s);
TS (h1->h2.e1.c1, s - o);
TS (h1->h2.e1.c2.a1, s - o2);
- TA (h1->h2.e1.c2.a2, s - o2, sizeof (h1->h2.e1.c2.a2));
+ TA (h1->h2.e1.c2.a2, s - o2, s - o2);
TF (h1->h2.e2, s - o);
s = o2 + 212;
TS (h2->h1, s);
TS (h2->h2.e1.c1, s - o);
TS (h2->h2.e1.c2.a1, s - o2);
- TA (h2->h2.e1.c2.a2, s - o2, sizeof (h2->h2.e1.c2.a2));
+ TA (h2->h2.e1.c2.a2, s - o2, s - o2);
TF (h2->h2.e2, s - o);
free (h2);
free (h1);
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-flex-common.h b/gcc/testsuite/gcc.dg/builtin-object-size-flex-common.h
new file mode 100644
index 00000000000..b8b68da762d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-flex-common.h
@@ -0,0 +1,90 @@
+#include "builtin-object-size-common.h"
+
+typedef __SIZE_TYPE__ size_t;
+
+void
+__attribute__ ((noinline))
+test_flexarray_allocate (const char *name)
+{
+ size_t n = sizeof (flex_t);
+
+ if (name != (void *) 0)
+ n += __builtin_strlen (name) + 1;
+
+ flex_t *p = __builtin_malloc (n);
+
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 0)
+ != n - sizeof (*p) + SIZEOF_FLEX_ARRAY)
+ FAIL ();
+
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 1)
+ != n - sizeof (*p) + SIZEOF_FLEX_ARRAY)
+ FAIL ();
+
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 2)
+ != n - sizeof (*p) + SIZEOF_FLEX_ARRAY)
+ FAIL ();
+
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 3)
+ != n - sizeof (*p) + SIZEOF_FLEX_ARRAY)
+ FAIL ();
+
+ __builtin_free (p);
+}
+
+void
+__attribute__ ((noinline))
+__attribute__ ((access (read_only, 1, 2)))
+test_flexarray_access (flex_t *p, size_t sz)
+{
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 0)
+ != (sz - 1) * sizeof (*p) + SIZEOF_FLEX_ARRAY)
+ FAIL ();
+
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 1)
+ != (sz - 1) * sizeof (*p) + SIZEOF_FLEX_ARRAY)
+ FAIL ();
+
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 2)
+ != (sz - 1) * sizeof (*p) + SIZEOF_FLEX_ARRAY)
+ FAIL ();
+
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 3)
+ != (sz - 1) * sizeof (*p) + SIZEOF_FLEX_ARRAY)
+ FAIL ();
+}
+
+void
+__attribute__ ((noinline))
+test_flexarray_none (flex_t *p)
+{
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 0) != -1)
+ FAIL ();
+
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 1) != -1)
+ FAIL ();
+
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 2) != 0)
+ FAIL ();
+
+ if (__builtin_dynamic_object_size (FLEX_ARRAY (p), 3) != SIZEOF_FLEX_ARRAY)
+ FAIL ();
+}
+
+int
+main (int argc, char **argv)
+{
+ const char *str = "qwertyuiopasdfgghjklzxcvbnm";
+
+ test_flexarray_allocate (str);
+
+ const size_t sz = 1024;
+ flex_t *p = __builtin_malloc (sz * sizeof (*p));
+
+ test_flexarray_access (p, sz);
+
+ test_flexarray_none (p);
+ __builtin_free (p);
+
+ DONE ();
+}
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct-nonzero.c b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct-nonzero.c
new file mode 100644
index 00000000000..c50cd89a817
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct-nonzero.c
@@ -0,0 +1,6 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#define SIZEOF_FLEX_ARRAY 4
+
+#include "builtin-object-size-flex-nested-struct.c"
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct-zero.c b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct-zero.c
new file mode 100644
index 00000000000..554aece0b46
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct-zero.c
@@ -0,0 +1,6 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#define SIZEOF_FLEX_ARRAY 0
+
+#include "builtin-object-size-flex-nested-struct.c"
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct.c b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct.c
new file mode 100644
index 00000000000..1adeac16ac4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-struct.c
@@ -0,0 +1,22 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#ifndef SIZEOF_FLEX_ARRAY
+# define SIZEOF_FLEX_ARRAY_DECL
+# define SIZEOF_FLEX_ARRAY 0
+#else
+# define SIZEOF_FLEX_ARRAY_DECL SIZEOF_FLEX_ARRAY
+#endif
+
+typedef struct {
+ unsigned pad;
+ struct {
+ unsigned pad;
+ char data[SIZEOF_FLEX_ARRAY_DECL];
+ } s;
+} flex_t;
+
+#define FLEX_ARRAY(p) p->s.data
+#define SIZE_OF_FLEX sizeof (unsigned) + sizeof (unsigned)
+
+#include "builtin-object-size-flex-common.h"
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union-nonzero.c b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union-nonzero.c
new file mode 100644
index 00000000000..58e387c8db6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union-nonzero.c
@@ -0,0 +1,6 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#define SIZEOF_FLEX_ARRAY 4
+
+#include "builtin-object-size-flex-nested-union.c"
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union-zero.c b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union-zero.c
new file mode 100644
index 00000000000..ec6429a5a9b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union-zero.c
@@ -0,0 +1,6 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#define SIZEOF_FLEX_ARRAY 0
+
+#include "builtin-object-size-flex-nested-union.c"
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union.c b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union.c
new file mode 100644
index 00000000000..8326131c890
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nested-union.c
@@ -0,0 +1,28 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#ifndef SIZEOF_FLEX_ARRAY
+# define SIZEOF_FLEX_ARRAY_DECL
+# define SIZEOF_FLEX_ARRAY 0
+#else
+# define SIZEOF_FLEX_ARRAY_DECL SIZEOF_FLEX_ARRAY
+#endif
+
+typedef struct {
+ unsigned pad;
+ union {
+ struct {
+ unsigned pad;
+ char data[SIZEOF_FLEX_ARRAY_DECL];
+ } s1;
+ struct {
+ unsigned pad;
+ char data[SIZEOF_FLEX_ARRAY_DECL];
+ } s2;
+ } u;
+} flex_t;
+
+#define FLEX_ARRAY(p) p->u.s1.data
+#define SIZE_OF_FLEX sizeof (unsigned) + sizeof (unsigned)
+
+#include "builtin-object-size-flex-common.h"
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-flex-nonzero.c b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nonzero.c
new file mode 100644
index 00000000000..693d2e98758
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-flex-nonzero.c
@@ -0,0 +1,6 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#define SIZEOF_FLEX_ARRAY 4
+
+#include "builtin-object-size-flex.c"
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-flex-zero.c b/gcc/testsuite/gcc.dg/builtin-object-size-flex-zero.c
new file mode 100644
index 00000000000..f38d0e01d4b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-flex-zero.c
@@ -0,0 +1,6 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#define SIZEOF_FLEX_ARRAY 0
+
+#include "builtin-object-size-flex.c"
diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-flex.c b/gcc/testsuite/gcc.dg/builtin-object-size-flex.c
new file mode 100644
index 00000000000..34aba8942d6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-object-size-flex.c
@@ -0,0 +1,18 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#ifndef SIZEOF_FLEX_ARRAY
+# define SIZEOF_FLEX_ARRAY_DECL
+# define SIZEOF_FLEX_ARRAY 0
+#else
+# define SIZEOF_FLEX_ARRAY_DECL SIZEOF_FLEX_ARRAY
+#endif
+
+typedef struct {
+ unsigned pad;
+ char data[SIZEOF_FLEX_ARRAY_DECL];
+} flex_t;
+
+#define FLEX_ARRAY(p) p->data
+
+#include "builtin-object-size-flex-common.h"
diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
index d9f25397c71..98ee3c2b527 100644
--- a/gcc/tree-object-size.cc
+++ b/gcc/tree-object-size.cc
@@ -499,6 +499,19 @@ decl_init_size (tree decl, bool min)
return size;
}
+/* Return the size of SUBOBJ that is within VAR where the latter has VAR_SIZE
+ size. */
+
+static tree
+size_from_objects (const_tree subobj, const_tree var, tree var_size,
+ int object_size_type)
+{
+ tree bytes = compute_object_offset (subobj, var);
+
+ return (bytes != error_mark_node ? size_for_offset (var_size, bytes)
+ : size_unknown (object_size_type));
+}
+
/* Compute __builtin_object_size for PTR, which is a ADDR_EXPR.
OBJECT_SIZE_TYPE is the second argument from __builtin_object_size.
If unknown, return size_unknown (object_size_type). */
@@ -589,105 +602,52 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
{
var = TREE_OPERAND (ptr, 0);
+ /* Get the immediate containing subobject. Skip over conversions
+ because we don't need them. */
while (var != pt_var
- && TREE_CODE (var) != BIT_FIELD_REF
- && TREE_CODE (var) != COMPONENT_REF
- && TREE_CODE (var) != ARRAY_REF
- && TREE_CODE (var) != ARRAY_RANGE_REF
- && TREE_CODE (var) != REALPART_EXPR
- && TREE_CODE (var) != IMAGPART_EXPR)
+ && (!handled_component_p (var)
+ || TREE_CODE (var) == VIEW_CONVERT_EXPR))
var = TREE_OPERAND (var, 0);
if (var != pt_var && TREE_CODE (var) == ARRAY_REF)
var = TREE_OPERAND (var, 0);
+
+ /* If the subobject size cannot be easily inferred or is smaller than
+ the whole size, just use the whole size. */
if (! TYPE_SIZE_UNIT (TREE_TYPE (var))
|| ! tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (var)))
|| (pt_var_size && TREE_CODE (pt_var_size) == INTEGER_CST
&& tree_int_cst_lt (pt_var_size,
TYPE_SIZE_UNIT (TREE_TYPE (var)))))
var = pt_var;
- else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF)
- {
- tree v = var;
- /* 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))
- {
- case ARRAY_REF:
- if (TYPE_SIZE_UNIT (TREE_TYPE (TREE_OPERAND (v, 0))))
- {
- tree domain
- = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (v, 0)));
- if (domain && TYPE_MAX_VALUE (domain))
- {
- v = NULL_TREE;
- break;
- }
- }
- v = TREE_OPERAND (v, 0);
- break;
- case REALPART_EXPR:
- case IMAGPART_EXPR:
- v = NULL_TREE;
- break;
- case COMPONENT_REF:
- if (TREE_CODE (TREE_TYPE (v)) != ARRAY_TYPE)
- {
- v = NULL_TREE;
- break;
- }
- is_flexible_array_mem_ref = array_ref_flexible_size_p (v);
- while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
- if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
- != UNION_TYPE
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
- != QUAL_UNION_TYPE)
- break;
- else
- v = TREE_OPERAND (v, 0);
- if (TREE_CODE (v) == COMPONENT_REF
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
- == RECORD_TYPE)
- {
- /* compute object size only if v is not a
- flexible array member. */
- if (!is_flexible_array_mem_ref)
- {
- v = NULL_TREE;
- break;
- }
- v = TREE_OPERAND (v, 0);
- }
- while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
- if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
- != UNION_TYPE
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
- != QUAL_UNION_TYPE)
- break;
- else
- v = TREE_OPERAND (v, 0);
- if (v != pt_var)
- v = NULL_TREE;
- else
- v = pt_var;
- break;
- default:
- v = pt_var;
- break;
- }
- if (v == pt_var)
- var = pt_var;
- }
}
else
var = pt_var;
+ bool is_flexible_array_mem_ref = false;
+ /* Find out if this is a flexible array. This will change
+ according to -fstrict-flex-arrays. */
+ if (var != pt_var && TREE_CODE (pt_var) == MEM_REF)
+ is_flexible_array_mem_ref = array_ref_flexible_size_p (var);
+
+ /* We cannot get a maximum estimate for a flex array without the
+ whole object size. */
+ if (is_flexible_array_mem_ref && !pt_var_size
+ && !(object_size_type & OST_MINIMUM))
+ return false;
+
if (var != pt_var)
{
- var_size = TYPE_SIZE_UNIT (TREE_TYPE (var));
- if (!TREE_CONSTANT (var_size))
- var_size = get_or_create_ssa_default_def (cfun, var_size);
+ /* For flexible arrays, we prefer the size based on the whole object
+ if it is available. */
+ if (is_flexible_array_mem_ref && pt_var_size)
+ var_size = size_from_objects (var, pt_var, pt_var_size,
+ object_size_type);
+ else
+ {
+ var_size = TYPE_SIZE_UNIT (TREE_TYPE (var));
+ if (!TREE_CONSTANT (var_size))
+ var_size = get_or_create_ssa_default_def (cfun, var_size);
+ }
if (!var_size)
return false;
}
@@ -695,23 +655,17 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
return false;
else
var_size = pt_var_size;
- bytes = compute_object_offset (TREE_OPERAND (ptr, 0), var);
- if (bytes != error_mark_node)
+
+ bytes = size_from_objects (TREE_OPERAND (ptr, 0), var, var_size,
+ object_size_type);
+
+ if (var != pt_var && pt_var_size && TREE_CODE (pt_var) == MEM_REF
+ && !is_flexible_array_mem_ref)
{
- bytes = size_for_offset (var_size, bytes);
- if (var != pt_var && pt_var_size && TREE_CODE (pt_var) == MEM_REF)
- {
- tree bytes2 = compute_object_offset (TREE_OPERAND (ptr, 0),
- pt_var);
- if (bytes2 != error_mark_node)
- {
- bytes2 = size_for_offset (pt_var_size, bytes2);
- bytes = size_binop (MIN_EXPR, bytes, bytes2);
- }
- }
+ tree bytes2 = size_from_objects (TREE_OPERAND (ptr, 0), pt_var,
+ pt_var_size, object_size_type);
+ bytes = size_binop (MIN_EXPR, bytes, bytes2);
}
- else
- bytes = size_unknown (object_size_type);
wholebytes
= object_size_type & OST_SUBOBJECT ? var_size : pt_var_wholesize;
--
2.38.1
next prev parent reply other threads:[~2022-12-21 22:26 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-21 22:25 [PATCH 0/2] __bos and " Siddhesh Poyarekar
2022-12-21 22:25 ` [PATCH 1/2] testsuite: Run __bos tests to completion Siddhesh Poyarekar
2023-01-31 12:33 ` Jakub Jelinek
2023-02-01 16:46 ` [committed v2] " Siddhesh Poyarekar
2022-12-21 22:25 ` Siddhesh Poyarekar [this message]
2023-01-26 16:20 ` [PATCH 2/2] tree-object-size: More consistent behaviour with flex arrays Qing Zhao
2023-01-26 17:16 ` Siddhesh Poyarekar
2023-01-26 17:42 ` Qing Zhao
2023-01-31 12:46 ` Jakub Jelinek
2023-01-31 13:01 ` Siddhesh Poyarekar
2023-01-03 14:30 ` [ping][PATCH 0/2] __bos and " Siddhesh Poyarekar
2023-01-11 13:14 ` [ping2][PATCH " Siddhesh Poyarekar
2023-01-20 19:38 ` [ping3][PATCH " Siddhesh Poyarekar
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