Commit graph

15 commits

Author SHA1 Message Date
Tom Tromey
817003ed46 Rewrite output redirection and logging
This patch changes how gdb output redirection is done.

Currently, output is done via the UI.  gdb_stdout, for example, is a
define the expands to an lvalue referencing a field in the current UI.
When redirecting, this field may temporarily be reset; and when
logging is enabled or disabled, this is also done.

This has lead to bugs where the combination of redirection and logging
results in use-after-free.  Crashes are readily observable; see the
new test cases.

This patch upends this.  Now, gdb_stdout is simply an rvalue, and
refers to the current interpreter.  The interpreter provides ui_files
that do whatever rewriting is needed (mostly for MI); then output is
forward to the current UI via an indirection (see the new
ui::passthrough_file).

The ui provides paging, logging, timestamps, and the final stream that
writes to an actual file descriptor.

Redirection is handled at the ui layer.  Rather than changing the
output pipeline, new ui_files are simply swapped in by rewriting
pointers, hopefully with a scoped_restore.

Redirecting at the ui layer means that interpreter rewriting is still
applied when capturing output.  This fixes one of the reported bugs.

Not changing the pipeline means that the problems with the combination
of redirect and logging simply vanish.  Logging just changes a flag
and doesn't involve object destruction.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=17697
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28620
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28798
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28948
Approved-By: Andrew Burgess <aburgess@redhat.com>
2026-02-09 08:15:44 -07:00
Tom Tromey
1a7734d6c5 Small cleanup to interpreter initialization
interp::inited is currently public, because interp_set does the task
of making sure the interpreter is only initialized a single time.
However, the interpreter can do this job itself, and this member can
be private.
2026-01-06 10:12:55 -07:00
Tom Tromey
4abc1ce2cc Update copyright dates to include 2026
This updates the copyright headers to include 2026.  I did this by
running gdb/copyright.py and then manually modifying a few files as
noted by the script.
2026-01-05 13:16:46 -07:00
Tom Tromey
5fe70629ce Change file initialization to use INIT_GDB_FILE macro
This patch introduces a new macro, INIT_GDB_FILE.  This is used to
replace the current "_initialize_" idiom when introducing a per-file
initialization function.  That is, rather than write:

    void _initialize_something ();
    void
    _initialize_something ()
    {
       ...
    }

... now you would write:

    INIT_GDB_FILE (something)
    {
       ...
    }

The macro handles both the declaration and definition of the function.

The point of this approach is that it makes it harder to accidentally
cause an initializer to be omitted; see commit 2711e475 ("Ensure
cooked_index_entry self-tests are run").  Specifically, the regexp now
used by make-init-c seems harder to trick.

New in v2: un-did some erroneous changes made by the script.

The bulk of this patch was written by script.
Regression tested on x86-64 Fedora 41.
2025-06-26 06:15:59 -06:00
Tom Tromey
d01e823438 Update copyright dates to include 2025
This updates the copyright headers to include 2025.  I did this by
running gdb/copyright.py and then manually modifying a few files as
noted by the script.

Approved-By: Eli Zaretskii <eliz@gnu.org>
2025-04-08 10:54:39 -06:00
Tom Tromey
5c51acfcce Don't allow new-ui to start the TUI
The TUI can't really work properly with new-ui, at least not as
currently written.  This patch changes new-ui to reject an attempt.
Attempting to make a DAP ui this way is also now rejected.

Regression tested on x86-64 Fedora 38.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29273
Approved-By: Andrew Burgess <aburgess@redhat.com>
2024-05-17 09:39:41 -06:00
Simon Marchi
18d2988e5d gdb, gdbserver, gdbsupport: remove includes of early headers
Now that defs.h, server.h and common-defs.h are included via the
`-include` option, it is no longer necessary for source files to include
them.  Remove all the inclusions of these files I could find.  Update
the generation scripts where relevant.

Change-Id: Ia026cff269c1b7ae7386dd3619bc9bb6a5332837
Approved-By: Pedro Alves <pedro@palves.net>
2024-03-26 21:13:22 -04:00
Tom Tromey
8bb8f83467 Fix gdb.interrupt race
gdb.interrupt was introduced to implement DAP request cancellation.
However, because it can be run from another thread, and because I
didn't look deeply enough at the implementation, it turns out to be
racy.

The fix here is to lock accesses to certain globals in extension.c.

Note that this won't work in the case where configure detects that the
C++ compiler doesn't provide thread support.  This version of the
patch disables DAP entirely in this situation.

Regression tested on x86-64 Fedora 38.  I also ran gdb.dap/pause.exp
in a thread-sanitizer build tree to make sure the reported race is
gone.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31263
2024-02-28 09:08:16 -07:00
Tom de Vries
05bf17f03b [gdb/dap] Fix race between dap startup and dap log file
In dap_gdb_start we do:
...
        append GDBFLAGS " -iex \"set debug dap-log-file $logfile\" -q -i=dap"
...

While the dap log file setting comes before the dap interpreter setting,
the order is the other way around:
- first, the dap interpreter is started
- second, the -iex commands are executed and the log file is initialized.

Consequently, there's a race between dap interpreter startup and dap log file
initialization.

This cannot be fixed by using -eiex instead.  Before the interpreter is
started, the "set debug dap-log-file" command is not yet registered.

Fix this by postponing the start of the DAP server until GDB has processed all
command files.

Tested on aarch64-linux.

Approved-By: Tom Tromey <tom@tromey.com>

PR dap/31386
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31386
2024-02-22 11:35:26 +01:00
Andrew Burgess
1d506c26d9 Update copyright year range in header of all files managed by GDB
This commit is the result of the following actions:

  - Running gdb/copyright.py to update all of the copyright headers to
    include 2024,

  - Manually updating a few files the copyright.py script told me to
    update, these files had copyright headers embedded within the
    file,

  - Regenerating gdbsupport/Makefile.in to refresh it's copyright
    date,

  - Using grep to find other files that still mentioned 2023.  If
    these files were updated last year from 2022 to 2023 then I've
    updated them this year to 2024.

I'm sure I've probably missed some dates.  Feel free to fix them up as
you spot them.
2024-01-12 15:49:57 +00:00
Tom de Vries
3c3e54d7b5 [gdb/dap] Disable DAP for python <= 3.5
DAP requires python module typing, which is supported starting python 3.5.

Make this formal by:
- disabling the dap interpreter for python version < 3.5
- returning 0 in allow_dap_tests for python version < 3.5

Approved-By: Tom Tromey <tom@tromey.com>

PR dap/30708
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30708
2023-08-02 23:14:58 +02:00
Simon Marchi
13d03262f2 gdb: move struct ui and related things to ui.{c,h}
I'd like to move some things so they become methods on struct ui.  But
first, I think that struct ui and the related things are big enough to
deserve their own file, instead of being scattered through top.{c,h} and
event-top.c.

Change-Id: I15594269ace61fd76ef80a7b58f51ff3ab6979bc
2023-05-01 15:40:54 -04:00
Pedro Alves
b885aea1bb Simplify interp::exec / interp_exec - let exceptions propagate
This patch implements a simplication that I suggested here:

  https://sourceware.org/pipermail/gdb-patches/2022-March/186320.html

Currently, the interp::exec virtual method interface is such that
subclass implementations must catch exceptions and then return them
via normal function return.

However, higher up the in chain, for the CLI we get to
interpreter_exec_cmd, which does:

  for (i = 1; i < nrules; i++)
    {
      struct gdb_exception e = interp_exec (interp_to_use, prules[i]);

      if (e.reason < 0)
	{
	  interp_set (old_interp, 0);
	  error (_("error in command: \"%s\"."), prules[i]);
	}
    }

and for MI we get to mi_cmd_interpreter_exec, which has:

  void
  mi_cmd_interpreter_exec (const char *command, char **argv, int argc)
  {
  ...
    for (i = 1; i < argc; i++)
      {
	struct gdb_exception e = interp_exec (interp_to_use, argv[i]);

	if (e.reason < 0)
	  error ("%s", e.what ());
      }
  }

Note that if those errors are reached, we lose the original
exception's error code.  I can't see why we'd want that.

And, I can't see why we need to have interp_exec catch the exception
and return it via the normal return path.  That's normally needed when
we need to handle propagating exceptions across C code, like across
readline or ncurses, but that's not the case here.

It seems to me that we can simplify things by removing some
try/catch-ing and just letting exceptions propagate normally.

Note, the "error in command" error shown above, which only exists in
the CLI interpreter-exec command, is only ever printed AFAICS if you
run "interpreter-exec console" when the top level interpreter is
already the console/tui.  Like:

 (gdb) interpreter-exec console "foobar"
 Undefined command: "foobar".  Try "help".
 error in command: "foobar".

You won't see it with MI's "-interpreter-exec console" from a top
level MI interpreter:

 (gdb)
 -interpreter-exec console "foobar"
 &"Undefined command: \"foobar\".  Try \"help\".\n"
 ^error,msg="Undefined command: \"foobar\".  Try \"help\"."
 (gdb)

nor with MI's "-interpreter-exec mi" from a top level MI interpreter:

 (gdb)
 -interpreter-exec mi "-foobar"
 ^error,msg="Undefined MI command: foobar",code="undefined-command"
 ^done
 (gdb)

in both these cases because MI's -interpreter-exec just does:

  error ("%s", e.what ());

You won't see it either when running an MI command with the CLI's
"interpreter-exec mi":

 (gdb) interpreter-exec mi "-foobar"
 ^error,msg="Undefined MI command: foobar",code="undefined-command"
 (gdb)

This last case is because MI's interp::exec implementation never
returns an error:

 gdb_exception
 mi_interp::exec (const char *command)
 {
   mi_execute_command_wrapper (command);
   return gdb_exception ();
 }

Thus I think that "error in command" error is pretty pointless, and
since it simplifies things to not have it, the patch just removes it.

The patch also ends up addressing an old FIXME.

Change-Id: I5a6432a80496934ac7127594c53bf5221622e393
Approved-By: Tom Tromey <tromey@adacore.com>
Approved-By: Kevin Buettner <kevinb@redhat.com>
2023-02-08 17:28:42 +00:00
Tom Tromey
5aea5eca6c Do not use PyObject_CallNoArgs
PyObject_CallNoArgs was introduced in Python 3.9, so avoid it in favor
of PyObject_CallObject.
2023-01-03 07:13:01 -07:00
Tom Tromey
de7d7cb58e Initial implementation of Debugger Adapter Protocol
The Debugger Adapter Protocol is a JSON-RPC protocol that IDEs can use
to communicate with debuggers.  You can find more information here:

    https://microsoft.github.io/debug-adapter-protocol/

Frequently this is implemented as a shim, but it seemed to me that GDB
could implement it directly, via the Python API.  This patch is the
initial implementation.

DAP is implemented as a new "interp".  This is slightly weird, because
it doesn't act like an ordinary interpreter -- for example it doesn't
implement a command syntax, and doesn't use GDB's ordinary event loop.
However, this seemed like the best approach overall.

To run GDB in this mode, use:

    gdb -i=dap

The DAP code will accept JSON-RPC messages on stdin and print
responses to stdout.  GDB redirects the inferior's stdout to a new
pipe so that output can be encapsulated by the protocol.

The Python code uses multiple threads to do its work.  Separate
threads are used for reading JSON from the client and for writing JSON
to the client.  All GDB work is done in the main thread.  (The first
implementation used asyncio, but this had some limitations, and so I
rewrote it to use threads instead.)

This is not a complete implementation of the protocol, but it does
implement enough to demonstrate that the overall approach works.

There is a rudimentary test suite.  It uses a JSON parser written in
pure Tcl.  This parser is under the same license as Tcl itself, so I
felt it was acceptable to simply import it into the tree.

There is also a bit of documentation -- just documenting the new
interpreter name.
2023-01-02 09:49:37 -07:00