[PATCH] Disallow pseudo-registers in agent expression.

andrzej zaborowski
2008-01-26T19:08:02Z

Collecting a pseudo-register in a tracepoint action gives a failed
assert and probably wouldn't work anyway:

(gdb) action
Enter actions for tracepoint 1, one per line.
End with a line saying just "end".
> collect $pc
regcache.c:163: internal-error: register_type: Assertion `regnum >= 0
&& regnum < descr->nr_cooked_registers' failed.
A problem internal to GDB has been detected,

The patch also prevents a segfault when "action" or "while-stepping"
is ended with a ^D.

Attached is a mailer-unmangled version of the same file:
diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c
--- a/gdb/ax-gdb.c
+++ b/gdb/ax-gdb.c
@@ -1607,6 +1607,8 @@ gen_expr (union exp_element **pc, struct agent_expr *ax,
if (reg == -1)
internal_error (__FILE__, __LINE__,
_("Register $%s not available"), name);
+ if (reg >= gdbarch_num_regs (current_gdbarch))
+ error (_("GDB agent expressions cannot use pseudo-registers."));
value->kind = axs_lvalue_register;
value->u.reg = reg;
value->type = register_type (current_gdbarch, reg);
index 2d744ae..ba57fee 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -862,8 +862,11 @@ read_actions (struct tracepoint *t)
line = gdb_readline (0);

if (!line)
- line = "end";
-
+ {
+ line = xstrdup ("end");
+ printf_filtered ("end\n");
+ }
+
linetype = validate_actionline (&line, t);
if (linetype == BADLINE)
continue; /* already warned -- collect another line */