On Wed, 1 Feb 2023, Qing Zhao wrote:
>
>
> > On Feb 1, 2023, at 6:41 AM, Richard Biener <rguent...@suse.de> wrote:
> >
> > On Tue, 31 Jan 2023, Qing Zhao wrote:
> >
> >> GCC extension accepts the case when a struct with a flexible array member
> >> is embedded into another struct (possibly recursively).
> >> __builtin_object_size should treat such struct as flexible size per
> >> -fstrict-flex-arrays.
> >>
> >> PR tree-optimization/101832
> >>
> >> gcc/ChangeLog:
> >>
> >> PR tree-optimization/101832
> >> * tree-object-size.cc (flexible_size_type_p): New function.
> >> (addr_object_size): Handle structure/union type when it has
> >> flexible size.
> >>
> >> gcc/testsuite/ChangeLog:
> >>
> >> PR tree-optimization/101832
> >> * gcc.dg/builtin-object-size-pr101832-2.c: New test.
> >> * gcc.dg/builtin-object-size-pr101832-3.c: New test.
> >> * gcc.dg/builtin-object-size-pr101832-4.c: New test.
> >> * gcc.dg/builtin-object-size-pr101832.c: New test.
> >> ---
> >> .../gcc.dg/builtin-object-size-pr101832-2.c | 135 ++++++++++++++++++
> >> .../gcc.dg/builtin-object-size-pr101832-3.c | 135 ++++++++++++++++++
> >> .../gcc.dg/builtin-object-size-pr101832-4.c | 135 ++++++++++++++++++
> >> .../gcc.dg/builtin-object-size-pr101832.c | 119 +++++++++++++++
> >> gcc/tree-object-size.cc | 115 +++++++++++----
> >> 5 files changed, 611 insertions(+), 28 deletions(-)
> >> create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-pr101832-2.c
> >> create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-pr101832-3.c
> >> create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-pr101832-4.c
> >> create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-pr101832.c
> >>
> >> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-2.c
> >> b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-2.c
> >> new file mode 100644
> >> index 00000000000..f38babc5415
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-2.c
> >> @@ -0,0 +1,135 @@
> >> +/* PR 101832:
> >> + GCC extension accepts the case when a struct with a flexible array
> >> member
> >> + is embedded into another struct (possibly recursively).
> >> + __builtin_object_size will treat such struct as flexible size per
> >> + -fstrict-flex-arrays. */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2 -fstrict-flex-arrays=1" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +unsigned n_fails = 0;
> >> +
> >> +#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); \
> >> + n_fails++; \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct A {
> >> + int n;
> >> + char data[];/* Content following header */
> >> +};
> >> +
> >> +struct B {
> >> + int m;
> >> + struct A a;
> >> +};
> >> +
> >> +struct C {
> >> + int q;
> >> + struct B b;
> >> +};
> >> +
> >> +struct A0 {
> >> + int n;
> >> + char data[0];/* Content following header */
> >> +};
> >> +
> >> +struct B0 {
> >> + int m;
> >> + struct A0 a;
> >> +};
> >> +
> >> +struct C0 {
> >> + int q;
> >> + struct B0 b;
> >> +};
> >> +
> >> +struct A1 {
> >> + int n;
> >> + char data[1];/* Content following header */
> >> +};
> >> +
> >> +struct B1 {
> >> + int m;
> >> + struct A1 a;
> >> +};
> >> +
> >> +struct C1 {
> >> + int q;
> >> + struct B1 b;
> >> +};
> >> +
> >> +struct An {
> >> + int n;
> >> + char data[8];/* Content following header */
> >> +};
> >> +
> >> +struct Bn {
> >> + int m;
> >> + struct An a;
> >> +};
> >> +
> >> +struct Cn {
> >> + int q;
> >> + struct Bn b;
> >> +};
> >> +
> >> +volatile void *magic1, *magic2;
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + struct B *outer;
> >> + struct C *outest;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outer = (void *)magic1;
> >> + outest = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer->a, 1), -1);
> >> + expect(__builtin_object_size(&outest->b, 1), -1);
> >> + expect(__builtin_object_size(&outest->b.a, 1), -1);
> >> +
> >> + struct B0 *outer0;
> >> + struct C0 *outest0;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outer0 = (void *)magic1;
> >> + outest0 = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer0->a, 1), -1);
> >> + expect(__builtin_object_size(&outest0->b, 1), -1);
> >> + expect(__builtin_object_size(&outest0->b.a, 1), -1);
> >> +
> >> + struct B1 *outer1;
> >> + struct C1 *outest1;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outer1 = (void *)magic1;
> >> + outest1 = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer1->a, 1), -1);
> >> + expect(__builtin_object_size(&outest1->b, 1), -1);
> >> + expect(__builtin_object_size(&outest1->b.a, 1), -1);
> >> +
> >> + struct Bn *outern;
> >> + struct Cn *outestn;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outern = (void *)magic1;
> >> + outestn = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outern->a, 1), sizeof(outern->a));
> >> + expect(__builtin_object_size(&outestn->b, 1), sizeof(outestn->b));
> >> + expect(__builtin_object_size(&outestn->b.a, 1), sizeof(outestn->b.a));
> >> +
> >> + if (n_fails > 0)
> >> + __builtin_abort ();
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-3.c
> >> b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-3.c
> >> new file mode 100644
> >> index 00000000000..aaae99b8d67
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-3.c
> >> @@ -0,0 +1,135 @@
> >> +/* PR 101832:
> >> + GCC extension accepts the case when a struct with a flexible array
> >> member
> >> + is embedded into another struct (possibly recursively).
> >> + __builtin_object_size will treat such struct as flexible size per
> >> + -fstrict-flex-arrays. */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2 -fstrict-flex-arrays=2" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +unsigned n_fails = 0;
> >> +
> >> +#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); \
> >> + n_fails++; \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct A {
> >> + int n;
> >> + char data[];/* Content following header */
> >> +};
> >> +
> >> +struct B {
> >> + int m;
> >> + struct A a;
> >> +};
> >> +
> >> +struct C {
> >> + int q;
> >> + struct B b;
> >> +};
> >> +
> >> +struct A0 {
> >> + int n;
> >> + char data[0];/* Content following header */
> >> +};
> >> +
> >> +struct B0 {
> >> + int m;
> >> + struct A0 a;
> >> +};
> >> +
> >> +struct C0 {
> >> + int q;
> >> + struct B0 b;
> >> +};
> >> +
> >> +struct A1 {
> >> + int n;
> >> + char data[1];/* Content following header */
> >> +};
> >> +
> >> +struct B1 {
> >> + int m;
> >> + struct A1 a;
> >> +};
> >> +
> >> +struct C1 {
> >> + int q;
> >> + struct B1 b;
> >> +};
> >> +
> >> +struct An {
> >> + int n;
> >> + char data[8];/* Content following header */
> >> +};
> >> +
> >> +struct Bn {
> >> + int m;
> >> + struct An a;
> >> +};
> >> +
> >> +struct Cn {
> >> + int q;
> >> + struct Bn b;
> >> +};
> >> +
> >> +volatile void *magic1, *magic2;
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + struct B *outer;
> >> + struct C *outest;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outer = (void *)magic1;
> >> + outest = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer->a, 1), -1);
> >> + expect(__builtin_object_size(&outest->b, 1), -1);
> >> + expect(__builtin_object_size(&outest->b.a, 1), -1);
> >> +
> >> + struct B0 *outer0;
> >> + struct C0 *outest0;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outer0 = (void *)magic1;
> >> + outest0 = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer0->a, 1), -1);
> >> + expect(__builtin_object_size(&outest0->b, 1), -1);
> >> + expect(__builtin_object_size(&outest0->b.a, 1), -1);
> >> +
> >> + struct B1 *outer1;
> >> + struct C1 *outest1;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outer1 = (void *)magic1;
> >> + outest1 = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer1->a, 1), sizeof(outer1->a));
> >> + expect(__builtin_object_size(&outest1->b, 1), sizeof(outest1->b));
> >> + expect(__builtin_object_size(&outest1->b.a, 1), sizeof(outest1->b.a));
> >> +
> >> + struct Bn *outern;
> >> + struct Cn *outestn;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outern = (void *)magic1;
> >> + outestn = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outern->a, 1), sizeof(outern->a));
> >> + expect(__builtin_object_size(&outestn->b, 1), sizeof(outestn->b));
> >> + expect(__builtin_object_size(&outestn->b.a, 1), sizeof(outestn->b.a));
> >> +
> >> + if (n_fails > 0)
> >> + __builtin_abort ();
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-4.c
> >> b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-4.c
> >> new file mode 100644
> >> index 00000000000..424264e2acd
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832-4.c
> >> @@ -0,0 +1,135 @@
> >> +/* PR 101832:
> >> + GCC extension accepts the case when a struct with a flexible array
> >> member
> >> + is embedded into another struct (possibly recursively).
> >> + __builtin_object_size will treat such struct as flexible size per
> >> + -fstrict-flex-arrays. */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2 -fstrict-flex-arrays=3" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +unsigned n_fails = 0;
> >> +
> >> +#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); \
> >> + n_fails++; \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct A {
> >> + int n;
> >> + char data[];/* Content following header */
> >> +};
> >> +
> >> +struct B {
> >> + int m;
> >> + struct A a;
> >> +};
> >> +
> >> +struct C {
> >> + int q;
> >> + struct B b;
> >> +};
> >> +
> >> +struct A0 {
> >> + int n;
> >> + char data[0];/* Content following header */
> >> +};
> >> +
> >> +struct B0 {
> >> + int m;
> >> + struct A0 a;
> >> +};
> >> +
> >> +struct C0 {
> >> + int q;
> >> + struct B0 b;
> >> +};
> >> +
> >> +struct A1 {
> >> + int n;
> >> + char data[1];/* Content following header */
> >> +};
> >> +
> >> +struct B1 {
> >> + int m;
> >> + struct A1 a;
> >> +};
> >> +
> >> +struct C1 {
> >> + int q;
> >> + struct B1 b;
> >> +};
> >> +
> >> +struct An {
> >> + int n;
> >> + char data[8];/* Content following header */
> >> +};
> >> +
> >> +struct Bn {
> >> + int m;
> >> + struct An a;
> >> +};
> >> +
> >> +struct Cn {
> >> + int q;
> >> + struct Bn b;
> >> +};
> >> +
> >> +volatile void *magic1, *magic2;
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + struct B *outer;
> >> + struct C *outest;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outer = (void *)magic1;
> >> + outest = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer->a, 1), -1);
> >> + expect(__builtin_object_size(&outest->b, 1), -1);
> >> + expect(__builtin_object_size(&outest->b.a, 1), -1);
> >> +
> >> + struct B0 *outer0;
> >> + struct C0 *outest0;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outer0 = (void *)magic1;
> >> + outest0 = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer0->a, 1), sizeof(outer0->a));
> >> + expect(__builtin_object_size(&outest0->b, 1), sizeof(outest0->b));
> >> + expect(__builtin_object_size(&outest0->b.a, 1), sizeof(outest0->b.a));
> >> +
> >> + struct B1 *outer1;
> >> + struct C1 *outest1;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outer1 = (void *)magic1;
> >> + outest1 = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer1->a, 1), sizeof(outer1->a));
> >> + expect(__builtin_object_size(&outest1->b, 1), sizeof(outest1->b));
> >> + expect(__builtin_object_size(&outest1->b.a, 1), sizeof(outest1->b.a));
> >> +
> >> + struct Bn *outern;
> >> + struct Cn *outestn;
> >> +
> >> + /* Make sure optimization can't find some other object size. */
> >> + outern = (void *)magic1;
> >> + outestn = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outern->a, 1), sizeof(outern->a));
> >> + expect(__builtin_object_size(&outestn->b, 1), sizeof(outestn->b));
> >> + expect(__builtin_object_size(&outestn->b.a, 1), sizeof(outestn->b.a));
> >> +
> >> + if (n_fails > 0)
> >> + __builtin_abort ();
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-pr101832.c
> >> b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832.c
> >> new file mode 100644
> >> index 00000000000..8ed6980edf0
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-pr101832.c
> >> @@ -0,0 +1,119 @@
> >> +/* PR 101832:
> >> + GCC extension accepts the case when a struct with a flexible array
> >> member
> >> + is embedded into another struct (possibly recursively).
> >> + __builtin_object_size will treat such struct as flexible size per
> >> + -fstrict-flex-arrays. */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O2" } */
> >> +
> >> +#include <stdio.h>
> >> +
> >> +unsigned n_fails = 0;
> >> +
> >> +#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); \
> >> + n_fails++; \
> >> + } \
> >> +} while (0);
> >> +
> >> +struct A {
> >> + int n;
> >> + char data[];/* Content following header */
> >> +};
> >> +
> >> +struct B {
> >> + int m;
> >> + struct A a;
> >> +};
> >> +
> >> +struct C {
> >> + int q;
> >> + struct B b;
> >> +};
> >> +
> >> +struct A0 {
> >> + int n;
> >> + char data[0];/* Content following header */
> >> +};
> >> +
> >> +struct B0 {
> >> + int m;
> >> + struct A0 a;
> >> +};
> >> +
> >> +struct C0 {
> >> + int q;
> >> + struct B0 b;
> >> +};
> >> +
> >> +struct A1 {
> >> + int n;
> >> + char data[1];/* Content following header */
> >> +};
> >> +
> >> +struct B1 {
> >> + int m;
> >> + struct A1 a;
> >> +};
> >> +
> >> +struct C1 {
> >> + int q;
> >> + struct B1 b;
> >> +};
> >> +
> >> +struct An {
> >> + int n;
> >> + char data[8];/* Content following header */
> >> +};
> >> +
> >> +struct Bn {
> >> + int m;
> >> + struct An a;
> >> +};
> >> +
> >> +struct Cn {
> >> + int q;
> >> + struct Bn b;
> >> +};
> >> +
> >> +volatile void *magic1, *magic2;
> >> +
> >> +int main(int argc, char *argv[])
> >> +{
> >> + struct B *outer = (void *)magic1;
> >> + struct C *outest = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer->a, 1), -1);
> >> + expect(__builtin_object_size(&outest->b, 1), -1);
> >> + expect(__builtin_object_size(&outest->b.a, 1), -1);
> >> +
> >> + struct B0 *outer0 = (void *)magic1;
> >> + struct C0 *outest0 = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer0->a, 1), -1);
> >> + expect(__builtin_object_size(&outest0->b, 1), -1);
> >> + expect(__builtin_object_size(&outest0->b.a, 1), -1);
> >> +
> >> + struct B1 *outer1 = (void *)magic1;
> >> + struct C1 *outest1 = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outer1->a, 1), -1);
> >> + expect(__builtin_object_size(&outest1->b, 1), -1);
> >> + expect(__builtin_object_size(&outest1->b.a, 1), -1);
> >> +
> >> + struct Bn *outern = (void *)magic1;
> >> + struct Cn *outestn = (void *)magic2;
> >> +
> >> + expect(__builtin_object_size(&outern->a, 1), -1);
> >> + expect(__builtin_object_size(&outestn->b, 1), -1);
> >> + expect(__builtin_object_size(&outestn->b.a, 1), -1);
> >> +
> >> + if (n_fails > 0)
> >> + __builtin_abort ();
> >> +
> >> + return 0;
> >> +}
> >> diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
> >> index 9a936a91983..56b78ca2a8c 100644
> >> --- a/gcc/tree-object-size.cc
> >> +++ b/gcc/tree-object-size.cc
> >> @@ -500,6 +500,42 @@ decl_init_size (tree decl, bool min)
> >> return size;
> >> }
> >>
> >> +/* Determine whether TYPE is a structure with a flexible array member
> >> + per -fstrict-flex-array or a union containing such a structure
> >> + (possibly recursively). */
> >> +static bool
> >> +flexible_size_type_p (const_tree type)
> >> +{
> >> + tree x = NULL_TREE;
> >> + tree last = NULL_TREE;
> >> + switch (TREE_CODE (type))
> >> + {
> >> + case RECORD_TYPE:
> >> + for (x = TYPE_FIELDS (type); x != NULL_TREE; x = DECL_CHAIN (x))
> >> + if (TREE_CODE (x) == FIELD_DECL)
> >> + last = x;
> >> + if (last == NULL_TREE)
> >> + return false;
> >> + if (TREE_CODE (TREE_TYPE (last)) == ARRAY_TYPE
> >> + && !DECL_NOT_FLEXARRAY (last))
> >> + return true;
> >> + else if (TREE_CODE (TREE_TYPE (last)) == RECORD_TYPE
> >> + || TREE_CODE (TREE_TYPE (last)) == UNION_TYPE)
> >> + return flexible_size_type_p (TREE_TYPE (last));
> >
> > For types with many members this can become quite slow (IIRC we had
> > bugs about similar walks of all fields in types), and this function
> > looks like it's invoked multiple times on the same type per TU.
> >
> > In principle the property is fixed at the time we lay out a record
> > type, so we might want to compute it at that time and record the
> > result.
>
> You mean in FE?
Yes, either in the frontend or in the middle-ends layout_type.
> Yes, that?s better and cleaner.
>
> I will add one more field in the TYPE structure to record this information
> and check this field during middle end.
>
> I had the same thought in the beginning, but not sure whether adding a
> new field in IR is necessary or not, other places in middle end might
> not use this new field.
It might be interesting to search for other code walking all fields of
a type to determine this or similar info.
> thanks.
>
> Qing
>
> >
> >> + return false;
> >> + case UNION_TYPE:
> >> + for (x = TYPE_FIELDS (type); x != NULL_TREE; x = DECL_CHAIN (x))
> >> + {
> >> + if (TREE_CODE (x) == FIELD_DECL
> >> + && flexible_array_type_p (TREE_TYPE (x)))
> >> + return true;
> >> + }
> >> + return false;
> >> + default:
> >> + return false;
> >> + }
> >> +}
> >> +
> >> /* 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). */
> >> @@ -633,45 +669,68 @@ addr_object_size (struct object_size_info *osi,
> >> const_tree ptr,
> >> v = NULL_TREE;
> >> break;
> >> case COMPONENT_REF:
> >> - if (TREE_CODE (TREE_TYPE (v)) != ARRAY_TYPE)
> >> + /* When the ref is not to an array, a record or a union, it
> >> + will not have flexible size, compute the object size
> >> + directly. */
> >> + if ((TREE_CODE (TREE_TYPE (v)) != ARRAY_TYPE)
> >> + && (TREE_CODE (TREE_TYPE (v)) != RECORD_TYPE)
> >> + && (TREE_CODE (TREE_TYPE (v)) != UNION_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)
> >> + /* if the record or union does not have flexible size
> >> + compute the object size directly. */
> >> + if (TREE_CODE (TREE_TYPE (v)) == RECORD_TYPE
> >> + || TREE_CODE (TREE_TYPE (v)) == UNION_TYPE)
> >> {
> >> - /* compute object size only if v is not a
> >> - flexible array member. */
> >> - if (!is_flexible_array_mem_ref)
> >> + if (!flexible_size_type_p (TREE_TYPE (v)))
> >> {
> >> v = NULL_TREE;
> >> break;
> >> }
> >> - v = TREE_OPERAND (v, 0);
> >> + else
> >> + 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;
> >> + {
> >> + /* Now the ref is to an array type. */
> >> + 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;
> >>
> >
> > --
> > Richard Biener <rguent...@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 <rguent...@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)
