This patch makes us deal with flexible array members and global
initializers correctly, thus for
struct s {
int i;
char c[];
} s = { 1, "01234" };
return 6 for the size of s.c instead of 0 (which is wrong, it
should have been reported as -1 instead - I didn't try to fix
that particular issue).
For the total size of the pointed-to object we can simply
use DECL_SIZE_UNIT instead of TYPE_SIZE_UNIT if it is a decl.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk,
queued for 4.6 (it's a wrong-code bug, but not a regression).
Richard.
2011-05-19 Richard Guenther <[email protected]>
PR middle-end/48985
* tree-object-size.c (addr_object_size): If the pointed-to
variable is a decl use DECL_SIZE_UNIT instead of TYPE_SIZE_UNIT.
* gcc.dg/builtin-object-size-11.c: New testcase.
Index: gcc/tree-object-size.c
===================================================================
*** gcc/tree-object-size.c (revision 173900)
--- gcc/tree-object-size.c (working copy)
*************** addr_object_size (struct object_size_inf
*** 205,210 ****
--- 205,216 ----
pt_var_size = size_int (sz);
}
else if (pt_var
+ && DECL_P (pt_var)
+ && host_integerp (DECL_SIZE_UNIT (pt_var), 1)
+ && (unsigned HOST_WIDE_INT)
+ tree_low_cst (DECL_SIZE_UNIT (pt_var), 1) < offset_limit)
+ pt_var_size = DECL_SIZE_UNIT (pt_var);
+ else if (pt_var
&& (SSA_VAR_P (pt_var) || TREE_CODE (pt_var) == STRING_CST)
&& TYPE_SIZE_UNIT (TREE_TYPE (pt_var))
&& host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (pt_var)), 1)
Index: gcc/testsuite/gcc.dg/builtin-object-size-11.c
===================================================================
*** gcc/testsuite/gcc.dg/builtin-object-size-11.c (revision 0)
--- gcc/testsuite/gcc.dg/builtin-object-size-11.c (revision 0)
***************
*** 0 ****
--- 1,20 ----
+ /* PR48985 */
+ /* { dg-do run } */
+
+ extern void abort (void);
+
+ struct s {
+ int i;
+ char c[];
+ } s = { 1, "01234" };
+
+ __SIZE_TYPE__ f (void) { return __builtin_object_size (&s.c, 0); }
+
+ int
+ main()
+ {
+ if (f() != sizeof ("01234"))
+ abort ();
+
+ return 0;
+ }
