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re PR c/41935 (ICE : tree check: expected integer_cst, have nop_expr in int_cst_value, at tree.c:8301) 

PR middle-end/41935
	* c-common.c (fold_offsetof_1) <case ARRAY_REF>: Don't crash for VLAs
	or non-constant index, allow index one past the last element and
	allow exceeding array bound in arrays that might be used as flexible
	array members.

	* gcc.dg/pr41935.c: New test.
	* c-c++-common/pr41935.c: New test.
	* c-c++-common/builtin-offsetof.c (f0): Allow index one past the last
	element.
	* gcc.c-torture/execute/pr41935.c: New test.

From-SVN: r153962
This commit is contained in:
Jakub Jelinek 2009-11-06 09:46:45 +01:00 committed by Jakub Jelinek
parent 21a15d9f83
commit d32599a6e9
7 changed files with 179 additions and 10 deletions
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8
gcc/ChangeLog
View File

@ -1,3 +1,11 @@
2009-11-06 Jakub Jelinek <jakub@redhat.com>
PR middle-end/41935
* c-common.c (fold_offsetof_1) <case ARRAY_REF>: Don't crash for VLAs
or non-constant index, allow index one past the last element and
allow exceeding array bound in arrays that might be used as flexible
array members.
2009-11-05 Richard Henderson <rth@redhat.com>
* config/i386/ia32intrin.h: Protect CRC32 builtins with __SSE4_2__.

48
gcc/c-common.c
View File

@ -8398,14 +8398,46 @@ fold_offsetof_1 (tree expr, tree stop_ref)
off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
/* Check if the offset goes beyond the upper bound of the array. */
{
tree nelts = array_type_nelts (TREE_TYPE (TREE_OPERAND (expr, 0)));
HOST_WIDE_INT index = int_cst_value (t);
if (index > int_cst_value (nelts))
warning (OPT_Warray_bounds,
"index %wd denotes an offset greater than size of %qT",
index, TREE_TYPE (TREE_OPERAND (expr, 0)));
}
if (code == PLUS_EXPR && TREE_CODE (t) == INTEGER_CST)
{
tree upbound = array_ref_up_bound (expr);
if (upbound != NULL_TREE
&& TREE_CODE (upbound) == INTEGER_CST
&& !tree_int_cst_equal (upbound,
TYPE_MAX_VALUE (TREE_TYPE (upbound))))
{
upbound = size_binop (PLUS_EXPR, upbound,
build_int_cst (TREE_TYPE (upbound), 1));
if (tree_int_cst_lt (upbound, t))
{
tree v;
for (v = TREE_OPERAND (expr, 0);
TREE_CODE (v) == COMPONENT_REF;
v = TREE_OPERAND (v, 0))
if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
== RECORD_TYPE)
{
tree fld_chain = TREE_CHAIN (TREE_OPERAND (v, 1));
for (; fld_chain; fld_chain = TREE_CHAIN (fld_chain))
if (TREE_CODE (fld_chain) == FIELD_DECL)
break;
if (fld_chain)
break;
}
/* Don't warn if the array might be considered a poor
man's flexible array member with a very permissive
definition thereof. */
if (TREE_CODE (v) == ARRAY_REF
|| TREE_CODE (v) == COMPONENT_REF)
warning (OPT_Warray_bounds,
"index %E denotes an offset "
"greater than size of %qT",
t, TREE_TYPE (TREE_OPERAND (expr, 0)));
}
}
}
break;
case COMPOUND_EXPR:

9
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,12 @@
2009-11-06 Jakub Jelinek <jakub@redhat.com>
PR middle-end/41935
* gcc.dg/pr41935.c: New test.
* c-c++-common/pr41935.c: New test.
* c-c++-common/builtin-offsetof.c (f0): Allow index one past the last
element.
* gcc.c-torture/execute/pr41935.c: New test.
2009-11-05 Jason Merrill <jason@redhat.com>
PR c++/34180

4
gcc/testsuite/c-c++-common/builtin-offsetof.c
View File

@ -21,9 +21,9 @@ f0 ()
__builtin_offsetof(struct A, p[0]); // { dg-error "non constant address" }
__builtin_offsetof(struct B, p[0]); // OK
__builtin_offsetof(struct B, p[9]); // OK
__builtin_offsetof(struct B, p[10]); // { dg-warning "greater than size" }
__builtin_offsetof(struct B, p[10]); // OK
__builtin_offsetof(struct B, p[11]); // { dg-warning "greater than size" }
__builtin_offsetof(struct B, a.p); // OK
__builtin_offsetof(struct B, p[0]); // OK
__builtin_offsetof(struct B, a.p[0]); // { dg-error "non constant address" }
}

70
gcc/testsuite/c-c++-common/pr41935.c Normal file
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@ -0,0 +1,70 @@
/* { dg-options "-Warray-bounds" } */
/* { dg-do compile } */
struct A
{
int i;
char p[1];
};
struct B
{
struct A a;
int i;
};
struct C
{
int i;
struct A a;
};
union D
{
char p[1];
struct A a;
struct B b;
struct C c;
};
struct E
{
int i;
union D d;
};
struct F
{
union D d;
int i;
};
union G
{
int i;
union D d;
};
void
f0 ()
{
__builtin_offsetof (struct A, p[4]); /* OK */
__builtin_offsetof (struct B, a.p[4]); /* { dg-warning "greater than size" } */
__builtin_offsetof (struct C, a.p[4]); /* OK */
__builtin_offsetof (union D, p[4]); /* OK */
__builtin_offsetof (union D, a.p[4]); /* OK */
__builtin_offsetof (union D, b.a.p[4]); /* { dg-warning "greater than size" } */
__builtin_offsetof (union D, c.a.p[4]); /* OK */
__builtin_offsetof (struct E, d.p[4]); /* OK */
__builtin_offsetof (struct E, d.a.p[4]); /* OK */
__builtin_offsetof (struct E, d.b.a.p[4]); /* { dg-warning "greater than size" } */
__builtin_offsetof (struct E, d.c.a.p[4]); /* OK */
__builtin_offsetof (struct F, d.p[4]); /* { dg-warning "greater than size" } */
__builtin_offsetof (struct F, d.a.p[4]); /* { dg-warning "greater than size" } */
__builtin_offsetof (struct F, d.b.a.p[4]); /* { dg-warning "greater than size" } */
__builtin_offsetof (struct F, d.c.a.p[4]); /* { dg-warning "greater than size" } */
__builtin_offsetof (union G, d.p[4]); /* OK */
__builtin_offsetof (union G, d.a.p[4]); /* OK */
__builtin_offsetof (union G, d.b.a.p[4]); /* { dg-warning "greater than size" } */
__builtin_offsetof (union G, d.c.a.p[4]); /* OK */
}

25
gcc/testsuite/gcc.c-torture/execute/pr41935.c Normal file
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@ -0,0 +1,25 @@
/* PR middle-end/41935 */
extern void abort (void);
long int
foo (int n, int i, int j)
{
typedef int T[n];
struct S { int a; T b[n]; };
return __builtin_offsetof (struct S, b[i][j]);
}
int
main (void)
{
typedef int T[5];
struct S { int a; T b[5]; };
if (foo (5, 2, 3)
!= __builtin_offsetof (struct S, b) + (5 * 2 + 3) * sizeof (int))
abort ();
if (foo (5, 5, 5)
!= __builtin_offsetof (struct S, b) + (5 * 5 + 5) * sizeof (int))
abort ();
return 0;
}

25
gcc/testsuite/gcc.dg/pr41935.c Normal file
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@ -0,0 +1,25 @@
/* PR middle-end/41935 */
/* { dg-do run } */
/* { dg-options "-O2" } */
extern void abort (void);
struct A { int a; int b[10]; };
int
foo (struct A *p)
{
return __builtin_offsetof (struct A, b[p->a]);
}
int
main ()
{
struct A a;
a.a = 7;
if (foo (&a) != 7 * sizeof (int) + __builtin_offsetof (struct A, b))
abort ();
a.a = 2;
if (foo (&a) != 2 * sizeof (int) + __builtin_offsetof (struct A, b))
abort ();
return 0;
}