re PR c++/38699 (ICE using offsetof with pointer and array accesses)

Fix PR c++/38699

gcc/ChangeLog:

	PR c++/38699
	* c-common.c (fold_offsetof_1): Issue errors when the member designator of
	the offsetoff expression is not legitimate.

gcc/testsuite/ChangeLog:

	* c-c++-common/dfp/builtin-offsetof.c: New test.
	* g++.dg/other/offsetof6.C: Likewise.

From-SVN: r153844
This commit is contained in:
Dodji Seketeli 2009-11-03 10:46:00 +00:00 committed by Dodji Seketeli
parent 62c5f254d0
commit 0ebe71e647
5 changed files with 83 additions and 7 deletions

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@ -1,3 +1,9 @@
2009-11-03 Dodji Seketeli <dodji@redhat.com>
PR c++/38699
* c-common.c (fold_offsetof_1): Issue errors when the member designator
of the offsetoff expression is not legitimate.
2009-10-28 Jakub Jelinek <jakub@redhat.com>
PR target/41762

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@ -7633,15 +7633,14 @@ fold_offsetof_1 (tree expr, tree stop_ref)
error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded");
return error_mark_node;
case INTEGER_CST:
gcc_assert (integer_zerop (expr));
return size_zero_node;
case NOP_EXPR:
case INDIRECT_REF:
base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
gcc_assert (base == error_mark_node || base == size_zero_node);
return base;
if (!integer_zerop (TREE_OPERAND (expr, 0)))
{
error ("cannot apply %<offsetof%> to a non constant address");
return error_mark_node;
}
return size_zero_node;
case COMPONENT_REF:
base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref);
@ -7673,6 +7672,16 @@ fold_offsetof_1 (tree expr, tree stop_ref)
}
t = convert (sizetype, t);
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 %ld denotes an offset greater than size of %qT",
index, TREE_TYPE (TREE_OPERAND (expr, 0)));
}
break;
case COMPOUND_EXPR:

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@ -1,3 +1,9 @@
2009-11-03 Dodji Seketeli <dodji@redhat.com>
PR c++/38699
* c-c++-common/dfp/builtin-offsetof.c: New test.
* g++.dg/other/offsetof6.C: Likewise.
2009-11-02 Dodji Seketeli <dodji@redhat.com>
PR c++/37093

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@ -0,0 +1,29 @@
// Contributed by Dodji Seketeli <dodji@redhat.com>
// Origin PR c++/38699
// { dg-options "-Warray-bounds" }
// { dg-do compile }
struct A
{
const char *p;
};
struct B
{
char p[10];
struct A a;
};
void
f0 ()
{
__builtin_offsetof(struct A, p); // OK
__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, a.p); // OK
__builtin_offsetof(struct B, p[0]); // OK
__builtin_offsetof(struct B, a.p[0]); // { dg-error "non constant address" }
}

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@ -0,0 +1,26 @@
// Contributed by Dodji Seketeli <dodji@redhat.com>
// Origin PR c++/38699
// { dg-do compile }
template<class T>
struct A
{
const T *p;
};
struct B
{
A<int> a;
};
template class A<char>;
void
f0 ()
{
__builtin_offsetof(A<char>, p); // OK
__builtin_offsetof(A<char>, p[1]); // { dg-error "non constant address" }
__builtin_offsetof(B, a.p); // OK
__builtin_offsetof(B, a.p[1]); // { dg-error "non constant address" }
}