/* Functions for manipulating expressions designed to be executed on the agent
- Copyright 1998, 1999, 2000 Free Software Foundation, Inc.
+ Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
This file is part of GDB.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA. */
/* Despite what the above comment says about this file being part of
GDB, we would like to keep these functions free of GDB
int reg_mask_len = 1;
unsigned char *reg_mask = xmalloc (reg_mask_len * sizeof (reg_mask[0]));
- /* Jump target table. targets[i] is non-zero iff there is a jump to
- offset i. */
+ /* Jump target table. targets[i] is non-zero iff we have found a
+ jump to offset i. */
char *targets = (char *) alloca (ax->len * sizeof (targets[0]));
- /* Instruction boundary table. boundary[i] is non-zero iff an
- instruction starts at offset i. */
+ /* Instruction boundary table. boundary[i] is non-zero iff our scan
+ has reached an instruction starting at offset i. */
char *boundary = (char *) alloca (ax->len * sizeof (boundary[0]));
- /* Stack height record. iff either targets[i] or boundary[i] is
+ /* Stack height record. If either targets[i] or boundary[i] is
non-zero, heights[i] is the height the stack should have before
executing the bytecode at that point. */
int *heights = (int *) alloca (ax->len * sizeof (heights[0]));
return;
}
- /* If this instruction is a jump target, does the current stack
- height match the stack height at the jump source? */
+ /* If this instruction is a forward jump target, does the
+ current stack height match the stack height at the jump
+ source? */
if (targets[i] && (heights[i] != height))
{
reqs->flaw = agent_flaw_height_mismatch;
xfree (reg_mask);
return;
}
- /* Have we already found other jumps to the same location? */
- else if (targets[target])
+
+ /* Do we have any information about what the stack height
+ should be at the target? */
+ if (targets[target] || boundary[target])
{
- if (heights[i] != height)
+ if (heights[target] != height)
{
reqs->flaw = agent_flaw_height_mismatch;
xfree (reg_mask);
return;
}
}
- else
- {
- targets[target] = 1;
- heights[target] = height;
- }
+
+ /* Record the target, along with the stack height we expect. */
+ targets[target] = 1;
+ heights[target] = height;
}
/* For unconditional jumps with a successor, check that the