[PATCH] dynamic printf
Hui Zhu
teawater@gmail.com
Thu Mar 1 14:04:00 GMT 2012
Hi Stan,
This work is really cool!
I will try to make KGTP support it when it commit to trunk.
+ case gdb_agent_op_printf:
+ {
+ int chan, nargs, slen, i;
+ int args[100];
Just use support 10 args, I suggest this line should be: int args[10];
+ char *format;
+
+ chan = aexpr->bytes[pc++];
+ nargs = aexpr->bytes[pc++];
+ slen = aexpr->bytes[pc++];
+ format = (char *) &(aexpr->bytes[pc]);
+ pc += slen;
+ for (i = 0; i < nargs; ++i)
+ {
+ args[i] = top;
Suggest add a check in this part, then when i bigger than 9, stop set
top tp args[i]
+ if (--sp >= 0)
+ top = stack[sp];
+ }
I think this part need keep, because all to value that in the stack
need be clean.
+ /* (should re-check format before calling?) */
+ printf (format,
+ args[0], args[1], args[2], args[3], args[4],
+ args[5], args[6], args[7], args[8], args[9]);
+ }
+ break;
+
Best,
Hui
On Wed, Feb 29, 2012 at 15:03, Stan Shebs <stanshebs@earthlink.net> wrote:
> This patch implements a "dynamic printf", which is basically a breakpoint
> with a printf;continue as its command list - but with additional features
> that make it more interesting. First, there is an option to send the result
> to the inferior's output stream rather than to the GDB console; second,
> there is an option to do the printing in a remote agent/stub; and third, the
> agent version can continue printf'ing even after GDB detaches(!).
>
> (For those who pay attention to the competitive landscape, this is an
> Ericsson-requested GDBification of a Wind River feature.)
>
> The syntax of the command is
>
> dprintf <location> <format>,<arg>,<arg>...
>
> where the location is as for breakpoints, while the format and args are as
> for the printf command. So you could have something like
>
> dprintf myfun "myfun args are %d,%d\n",arg1,arg2
>
> A setshow variable dprintf-style controls whether the printing is done by
> GDB, the inferior, or by a remote agent, and another variable
> disconnected-dprintf controls persistence upon disconnection, similarly to
> disconnected tracing.
>
> The patch itself is somewhat of a hack-n-slash through the middle of GDB,
> and there is much to critique. :-) Partly this is because I wanted to push
> through to a genuinely useful example of target-side breakpoint commands,
> rather than doing limited-functionality "commands" in the abstract. It also
> points up our continuing need for being able to define types of breakpoints
> by properties rather than adding enums... I borrowed some of Luis'
> target-side conditional code, and got some inspiration from Hui Zhu's
> previous try at a printf bytecode.
>
> Anyway, without further ado, here's the patch itself. I've skipped the
> testsuite for now, as I expect everybody will want nontrivial modifications.
> :-)
>
> Stan
>
> 2012-02-28 Stan Shebs <stan@codesourcery.com>
>
> Add dynamic printf.
> * breakpoint.h (enum bptype): New type bp_dprintf.
> (struct bp_target_info): New field commands and persist.
> (struct bp_location): New field cmd_bytecode.
> (struct breakpoint): New field extra_string.
> * breakpoint.c (dprintf_breakpoint_ops): New.
> (disconnected_dprintf): New global.
> (is_breakpoint): Add bp_dprintf.
> (parse_format_string): New function.
> (parse_cmd_to_aexpr): New function.
> (build_target_command_list): New function.
> (insert_bp_location): Call it.
> (remove_breakpoints_pid): Skip dprintf breakpoints.
> (bpstat_what): Add dprintf case.
> (bptype_string): Ditto.
> (print_one_breakpoint_location): Ditto.
> (init_bp_location): Ditto.
> (bkpt_print_mention): Ditto.
> (dprintf_style_enums): New array.
> (dprintf_style): New global.
> (glob_extra_string): New global.
> (init_breakpoint_sal): Handle extra string.
> (addr_string_to_sals): Ditto.
> (find_condition_and_thread): Add extra argument.
> (create_breakpoint): Save away additional text at end of command.
> (dprintf_command): New function.
> (_initialize_breakpoint): Add new commands.
> * common/ax.def (printf): New bytecode.
> * ax-gdb.c (gen_printf): New function.
> (agent_print_command): New function.
> (_initialize_ax_gdb): Add maint agent-printf command.
> * ax-gdb.h (gen_printf): Declare.
> * ax-general.c (ax_print): Add printf disassembly.
> * remote.c (remote_state) <cond_breakpoints>: New field.
> (PACKET_BreakpointCommandss): New enum.
> (remote_breakpoint_commands_feature): New function.
> (remote_protocol_features): Add new BreakpointCommands entry.
> (remote_can_run_breakpoint_commands): New function.
> (remote_add_target_side_commands): New function.
> (remote_insert_breakpoint): Call it.
> (remote_insert_hw_breakpoint): Ditto.
> (_initialize_remote): Add new packet configuration for
> target-side breakpoint commands.
> * target.h (struct target_ops): New field
> to_can_run_breakpoint_commands.
> (target_can_run_breakpoint_commands): New macro.
> * target.c (update_current_target): Handle
> to_can_run_breakpoint_commands.
>
> [gdbserver]
> * server.c (handle_query): Claim support for breakpoint commands.
> (process_point_options): Add command case.
> (process_serial_event): Leave running if there are printfs in
> effect.
> * mem-break.c (struct point_command_list): New struct.
> (struct breakpoint): New field command_list.
> (any_persistent_commands): New function.
> (add_commands_to_breakpoint): New function.
> (add_breakpoint_commands): New function.
> (gdb_no_commands_at_breakpoint): New function.
> (run_breakpoint_commands): New function.
> * mem-break.h (any_persistent_commands): Declare.
> (add_breakpoint_commands): Declare.
> (gdb_no_commands_at_breakpoint): Declare.
> (run_breakpoint_commands): Declare.
> * linux-low.c (linux_wait_1): Test for and run breakpoint commands
> locally.
> * ax.c (gdb_eval_agent_expr): Add printf opcode.
>
> [doc]
> * gdb.texinfo (Dynamic Printf): New subsection.
>
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