Commit graph

1114 commits

Author SHA1 Message Date
Andrew Burgess
0642912e83 gdb/python: allow Value.format_string to return styled output
Add a new argument to the gdb.Value.format_string method, 'styling'.
This argument is False by default.

When this argument is True, then the returned string can contain output
styling escape sequences.

When this argument is False, then the returned string will not contain
any styling escape sequences.

If the returned string is going to be printed to the user, then it is
often nice to retain the GDB styling.

For the testing, we need to adjust the TERM environment variable, as
we do for all the styling tests.  I'm now running all of the C tests
in gdb.python/py-format-string.exp in an environment where styling
could be generated, but only my new test should actually produce
styled output, hopefully this will catch the case where a bug might
cause format_string to always produce styled output.
2022-02-07 16:52:47 +00:00
Simon Marchi
5d0027b9ba gdb: remove SYMBOL_LINE macro
Add a getter and a setter for a symbol's line.  Remove the corresponding macro
and adjust all callers.

Change-Id: I229f2b8fcf938c07975f641361313a8761fad9a5
2022-02-06 16:03:47 -05:00
Simon Marchi
5f9c5a63ce gdb: remove SYMBOL_TYPE macro
Add a getter and a setter for a symbol's type.  Remove the corresponding
macro and adjust all callers.

Change-Id: Ie1a137744c5bfe1df4d4f9ae5541c5299577c8de
2022-02-06 16:03:47 -05:00
Simon Marchi
d9743061f9 gdb: remove SYMBOL_IS_ARGUMENT macro
Add a getter and a setter for whether a symbol is an argument.  Remove
the corresponding macro and adjust all callers.

Change-Id: I71b4f0465f3dfd2ed8b9e140bd3f7d5eb8d9ee81
2022-02-06 16:03:46 -05:00
Simon Marchi
7b3ecc7555 gdb: remove SYMBOL_OBJFILE_OWNED macro
Add a getter and a setter for whether a symbol is objfile owned.  Remove
the corresponding macro and adjust all callers.

Change-Id: Ib7ef3718d65553ae924ca04c3fd478b0f4f3147c
2022-02-06 16:03:46 -05:00
Simon Marchi
66d7f48f80 gdb: remove SYMBOL_CLASS macro, add getter
Change-Id: I83211d5a47efc0564386e5b5ea4a29c00b1fd46a
2022-02-06 16:03:46 -05:00
Simon Marchi
652099717d gdb: remove SYMTAB_OBJFILE macro
Remove the macro, replace with an equivalent method.

Change-Id: I8f9ecd290ad28502e53c1ceca5006ba78bf042eb
2022-02-06 16:03:46 -05:00
Simon Marchi
012cfab919 gdb: remove SYMTAB_BLOCKVECTOR macro
Remove the macro, replace with an equivalent method.

Change-Id: Id6fe2a79c04bcd6c69ccaefb7a69bc06a476288c
2022-02-06 16:03:46 -05:00
Simon Marchi
5b6074611e gdb: remove SYMTAB_LINETABLE macro, add getter/setter
Add a getter and a setter for a symtab's linetable.  Remove the
corresponding macro and adjust all callers.

Change-Id: I159183fc0ccd8e18ab937b3c2f09ef2244ec6e9c
2022-02-06 15:48:19 -05:00
Simon Marchi
c615965258 gdb: remove SYMTAB_COMPUNIT macro, add getter/setter
Add a getter and a setter for a symtab's compunit_symtab.  Remove the
corresponding macro and adjust all callers.

For brevity, I chose the name "compunit" instead of "compunit_symtab"
the the field, getter and setter names.  Since we are already in symtab
context, the _symtab suffix seems redundant.

Change-Id: I4b9b731c96e3594f7733e75af1e3d01bc0e4fe92
2022-02-06 15:48:19 -05:00
Simon Marchi
af39c5c874 gdb: remove COMPUNIT_BLOCKVECTOR macro, add getter/setter
Add a getter and a setter for a compunit_symtab's blockvector.  Remove
the corresponding macro and adjust all callers.

Change-Id: I99484c6619dcbbea7c5d89c72aa660316ca62f64
2022-02-06 15:48:18 -05:00
Simon Marchi
ab5f850eed gdb: remove COMPUNIT_PRODUCER macro, add getter/setter
Add a getter and a setter for a compunit_symtab's producer.  Remove the
corresponding macro and adjust all callers.

Change-Id: Ia1d6d8a0e247a08a21af23819d71e49b37d8931b
2022-02-06 15:48:18 -05:00
Simon Marchi
9821f3fa56 gdb: remove COMPUNIT_OBJFILE macro
Remove the macro, update all users to use the getter directly.

Change-Id: I3f0fd6f4455d1c4ebd5da73b561eb18a979ef1f6
2022-02-06 15:48:18 -05:00
Tom Tromey
2b53149244 Remove host_hex_value
I noticed that host_hex_value is redundant, because gdbsupport already
has fromhex.  This patch removes the former in favor of the latter.

Regression tested on x86-64 Fedora 34.
2022-02-04 07:37:22 -07:00
Andrew Burgess
2f6b20e2e0 gdb: fix formatting for help set/show extended-prompt
The formatting of the help text for 'help set extended-prompt' and
'help show extended-prompt' is a little off.

Here's the offending snippet:

    Substitutions are applied to VALUE to compute the real prompt.

    The currently defined substitutions are:
      \[	Begins a sequence of non-printing characters.
  \\	A backslash.
  \]	Ends a sequence of non-printing characters.
  \e	The ESC character.

Notice that the line for '\[' is indented more that the others.

Turns out this is due to how we build this help text, something which
is done in Python.  We extended a classes __doc__ string with some
dynamically generated text.

The classes doc string looks like this:

    """Set the extended prompt.

    Usage: set extended-prompt VALUE

    Substitutions are applied to VALUE to compute the real prompt.

    The currently defined substitutions are:
    """

Notice the closing """ are in a line of their own, and include some
white space just before.  It's this extra white space that's causing
the problem.

Fix the formatting issue by moving the """ to the end of the previous
line.  I then add the extra newline in at the point where the doc
string is merged with the dynamically generated text.

Now everything lines up correctly.
2022-02-02 16:33:05 +00:00
Jan Vrany
219c04fc3b gdb/python: fix gdb.Objfile.__repr__ () for dynamically compiled code
While experimenting with JIT reader API I realized that calling repr ()
on objfile created by JIT reader crashes GDB.

The problem was that objfpy_repr () called objfile_filename () which
returned NULL, causing PyString_FromFormat () to crash.

This commit fixes this problem by using objfile_name () instead of
objfile_filename (). This also makes consistent with the value of gdb.Objfile.filename variable.
2022-02-01 14:49:30 +00:00
Andrew Burgess
299953ca95 gdb/python: handle non utf-8 characters when source highlighting
This commit adds support for source files that contain non utf-8
characters when performing source styling using the Python pygments
package.  This does not change the behaviour of GDB when the GNU
Source Highlight library is used.

For the following problem description, assume that either GDB is built
without GNU Source Highlight support, of that this has been disabled
using 'maintenance set gnu-source-highlight enabled off'.

The initial problem reported was that a source file containing non
utf-8 characters would cause GDB to print a Python exception, and then
display the source without styling, e.g.:

  Python Exception <class 'UnicodeDecodeError'>: 'utf-8' codec can't decode byte 0xc0 in position 142: invalid start byte
  /* Source code here, without styling...  */

Further, as the user steps through different source files, each time
the problematic source file was evicted from the source cache, and
then later reloaded, the exception would be printed again.

Finally, this problem is only present when using Python 3, this issue
is not present for Python 2.

What makes this especially frustrating is that GDB can clearly print
the source file contents, they're right there...  If we disable
styling completely, or make use of the GNU Source Highlight library,
then everything is fine.  So why is there an error when we try to
apply styling using Python?

The problem is the use of PyString_FromString (which is an alias for
PyUnicode_FromString in Python 3), this function converts a C string
into a either a Unicode object (Py3) or a str object (Py2).  For
Python 2 there is no unicode encoding performed during this function
call, but for Python 3 the input is assumed to be a uft-8 encoding
string for the purpose of the conversion.  And here of course, is the
problem, if the source file contains non utf-8 characters, then it
should not be treated as utf-8, but that's what we do, and that's why
we get an error.

My first thought when looking at this was to spot when the
PyString_FromString call failed with a UnicodeDecodeError and silently
ignore the error.  This would mean that GDB would print the source
without styling, but would also avoid the annoying exception message.

However, I also make use of `pygmentize`, a command line wrapper
around the Python pygments module, which I use to apply syntax
highlighting in the output of `less`.  And this command line wrapper
is quite happy to syntax highlight my source file that contains non
utf-8 characters, so it feels like the problem should be solvable.

It turns out that inside the pygments module there is already support
for guessing the encoding of the incoming file content, if the
incoming content is not already a Unicode string.  This is what
happens for Python 2 where the incoming content is of `str` type.

We could try and make GDB smarter when it comes to converting C
strings into Python Unicode objects; this would probably require us to
just try a couple of different encoding schemes rather than just
giving up after utf-8.

However, I figure, why bother?  The pygments module already does this
for us, and the colorize API is not part of the documented external
API of GDB.  So, why not just change the colorize API, instead of the
content being a Unicode string (for Python 3), lets just make the
content be a bytes object.  The pygments module can then take
responsibility for guessing the encoding.

So, currently, the colorize API receives a unicode object, and returns
a unicode object.  I propose that the colorize API receive a bytes
object, and return a bytes object.
2022-01-26 23:12:52 +00:00
Tom Tromey
1285ce8629 Always call the wrap_here method
This changes all existing calls to wrap_here to call the method on the
appropriate ui_file instead.  The choice of ui_file is determined by
context.
2022-01-26 15:19:13 -07:00
Tom Tromey
6c92c33953 Convert wrap_here to use integer parameter
I think it only really makes sense to call wrap_here with an argument
consisting solely of spaces.  Given this, it seemed better to me that
the argument be an int, rather than a string.  This patch is the
result.  Much of it was written by a script.
2022-01-26 15:19:13 -07:00
Andrew Burgess
bbea680797 gdb/python: improve the auto help text for gdb.Parameter
This commit attempts to improve the help text that is generated for
gdb.Parameter objects when the user fails to provide their own
documentation.

Documentation for a gdb.Parameter is currently pulled from two
sources: the class documentation string, and the set_doc/show_doc
class attributes.  Thus, a fully documented parameter might look like
this:

  class Param_All (gdb.Parameter):
     """This is the class documentation string."""

     show_doc = "Show the state of this parameter"
     set_doc = "Set the state of this parameter"

     def get_set_string (self):
        val = "on"
        if (self.value == False):
           val = "off"
        return "Test Parameter has been set to " + val

     def __init__ (self, name):
        super (Param_All, self).__init__ (name, gdb.COMMAND_DATA, gdb.PARAM_BOOLEAN)
        self._value = True

  Param_All ('param-all')

Then in GDB we see this:

  (gdb) help set param-all
  Set the state of this parameter
  This is the class documentation string.

Which is fine.  But, if the user skips both of the documentation parts
like this:

  class Param_None (gdb.Parameter):

     def get_set_string (self):
        val = "on"
        if (self.value == False):
           val = "off"
        return "Test Parameter has been set to " + val

     def __init__ (self, name):
        super (Param_None, self).__init__ (name, gdb.COMMAND_DATA, gdb.PARAM_BOOLEAN)
        self._value = True

  Param_None ('param-none')

Now in GDB we see this:

  (gdb) help set param-none
  This command is not documented.
  This command is not documented.

That's not great, the duplicated text looks a bit weird.  If we drop
different parts we get different results.  Here's what we get if the
user drops the set_doc and show_doc attributes:

  (gdb) help set param-doc
  This command is not documented.
  This is the class documentation string.

That kind of sucks, we say it's undocumented, then proceed to print
the documentation.  Finally, if we drop the class documentation but
keep the set_doc and show_doc:

  (gdb) help set param-set-show
  Set the state of this parameter
  This command is not documented.

That seems OK.

So, I think there's room for improvement.

With this patch, for the four cases above we now see this:

  # All values provided by the user, no change in this case:
  (gdb) help set param-all
  Set the state of this parameter
  This is the class documentation string.

  # Nothing provided by the user, the first string is now different:
  (gdb) help set param-none
  Set the current value of 'param-none'.
  This command is not documented.

  # Only the class documentation is provided, the first string is
  # changed as in the previous case:
  (gdb) help set param-doc
  Set the current value of 'param-doc'.
  This is the class documentation string.

  # Only the set_doc and show_doc are provided, this case is unchanged
  # from before the patch:
  (gdb) help set param-set-show
  Set the state of this parameter
  This command is not documented.

The one place where this change might be considered a negative is when
dealing with prefix commands.  If we create a prefix command but don't
supply the set_doc / show_doc strings, then this is what we saw before
my patch:

  (gdb) python Param_None ('print param-none')
  (gdb) help set print
  set print, set pr, set p
  Generic command for setting how things print.

  List of set print subcommands:

  ... snip ...
  set print param-none -- This command is not documented.
  ... snip ...

And after my patch:

  (gdb) python Param_None ('print param-none')
  (gdb) help set print
  set print, set pr, set p
  Generic command for setting how things print.

  List of set print subcommands:

  ... snip ...
  set print param-none -- Set the current value of 'print param-none'.
  ... snip ...

This seems slightly less helpful than before, but I don't think its
terrible.

Additionally, I've changed what we print when the get_show_string
method is not provided in Python.

Back when gdb.Parameter was first added to GDB, we didn't provide a
show function when registering the internal command object within
GDB.  As a result, GDB would make use of its "magic" mangling of the
show_doc string to create a sentence that would display the current
value (see deprecated_show_value_hack in cli/cli-setshow.c).

However, when we added support for the get_show_string method to
gdb.Parameter, there was an attempt to maintain backward compatibility
by displaying the show_doc string with the current value appended, see
get_show_value in py-param.c.  Unfortunately, this isn't anywhere
close to what deprecated_show_value_hack does, and the results are
pretty poor, for example, this is GDB before my patch:

  (gdb) show param-none
  This command is not documented. off

I think we can all agree that this is pretty bad.

After my patch, we how show this:

  (gdb) show param-none
  The current value of 'param-none' is "off".

Which at least is a real sentence, even if it's not very informative.

This patch does change the way that the Python API behaves slightly,
but only in the cases when the user has missed providing GDB with some
information.  In most cases I think the new behaviour is a lot better,
there's the one case (noted above) which is a bit iffy, but I think is
still OK.

I've updated the existing gdb.python/py-parameter.exp test to cover
the modified behaviour.

Finally, I've updated the documentation to (I hope) make it clearer
how the various bits of help text come together.
2022-01-26 22:00:20 +00:00
Andrew Burgess
30a87e90be gdb/python: add gdb.history_count function
Add a new function gdb.history_count to the Python api, this function
returns an integer, the number of items in GDB's value history.

This is useful if you want to pull items from the history by their
absolute number, for example, if you wanted to show a complete history
list.  Previously we could figure out how many items are in the
history list by trying to fetch the items, and then catching the
exception when the item is not available, but having this function
seems nicer.
2022-01-26 21:58:12 +00:00
Tom Tromey
b583c328e7 Add a way to temporarily set a gdb parameter from Python
It's sometimes useful to temporarily set some gdb parameter from
Python.  Now that the 'endian' crash is fixed, and now that the
current language is no longer captured by the Python layer, it seems
reasonable to add a helper function for this situation.

This adds a new gdb.with_parameter function.  This creates a context
manager which temporarily sets some parameter to a specified value.
The old value is restored when the context is exited.  This is most
useful with the Python "with" statement:

   with gdb.with_parameter('language', 'ada'):
      ... do Ada stuff

This also adds a simple function to set a parameter,
gdb.set_parameter, as suggested by Andrew.

This is PR python/10790.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=10790
2022-01-26 06:49:51 -07:00
Tom Tromey
dedb7102b3 Fix another crash with gdb parameters in Python
While looking into the language-capturing issue, I found another way
to crash gdb using parameters from Python:

(gdb) python print(gdb.parameter('endian'))

(This is related to PR python/12188, though this patch isn't going to
fix what that bug is really about.)

The problem here is that the global variable that underlies the
"endian" parameter is initialized to NULL.  However, that's not a
valid value for an "enum" set/show parameter.

My understanding is that, in gdb, an "enum" parameter's underlying
variable must have a value that is "==" (not just strcmp-equal) to one
of the values coming from the enum array.  This invariant is relied on
in various places.

I started this patch by fixing the problem with "endian".  Then I
added some assertions to add_setshow_enum_cmd to try to catch other
problems of the same type.

This patch fixes all the problems that I found.  I also looked at all
the calls to add_setshow_enum_cmd to ensure that they were all
included in the gdb I tested.  I think they are: there are no calls in
nat-* files, or in remote-sim.c; and I was trying a build with all
targets, Python, and Guile enabled.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=12188
2022-01-26 06:49:51 -07:00
Tom Tromey
1da5d0e664 Change how Python architecture and language are handled
Currently, gdb's Python layer captures the current architecture and
language when "entering" Python code.  This has some undesirable
effects, and so this series changes how this is handled.

First, there is code like this:

  gdbpy_enter enter_py (python_gdbarch, python_language);

This is incorrect, because both of these are NULL when not otherwise
assigned.  This can cause crashes in some cases -- I've added one to
the test suite.  (Note that this crasher is just an example, other
ones along the same lines are possible.)

Second, when the language is captured in this way, it means that
Python code cannot affect the current language for its own purposes.
It's reasonable to want to write code like this:

    gdb.execute('set language mumble')
    ... stuff using the current language
    gdb.execute('set language previous-value')

However, this won't actually work, because the language is captured on
entry.  I've added a test to show this as well.

This patch changes gdb to try to avoid capturing the current values.
The Python concept of the current gdbarch is only set in those few
cases where a non-default value is computed or needed; and the
language is not captured at all -- instead, in the cases where it's
required, the current language is temporarily changed.
2022-01-26 06:49:51 -07:00
Tom Tromey
d4396e0e97 Reduce explicit use of gdb_stdout
In an earlier version of the pager rewrite series, it was important to
audit unfiltered output calls to see which were truly necessary.

This is no longer necessary, but it still seems like a decent cleanup
to change calls to avoid explicitly passing gdb_stdout.  That is,
rather than using something like fprintf_unfiltered with gdb_stdout,
the code ought to use plain printf_unfiltered instead.

This patch makes this change.  I went ahead and converted all the
_filtered calls I could find, as well, for the same clarity.
2022-01-25 15:22:49 -07:00
Tom Tromey
bf31fd38f0 Move gdb obstack code to gdbsupport
This moves the gdb-specific obstack code -- both extensions like
obconcat and obstack_strdup, and things like auto_obstack -- to
gdbsupport.
2022-01-18 10:14:42 -07:00
Andrew Burgess
61671e9792 gdb/python: add gdb.host_charset function
We already have gdb.target_charset and gdb.target_wide_charset.  This
commit adds gdb.host_charset along the same lines.
2022-01-12 16:00:07 +00:00
Hannes Domani
72df4c816f Fix inferior_thread attribute in new_thread event
Commit 72ee03ff58 fixed a use-after-move bug in add_thread_object, but
it changed the inferior_thread attribute to contain the inferior instead
of the actual thread.
This now uses the thread_obj in its new location instead.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28429
2022-01-05 18:35:20 +01:00
Joel Brobecker
4a94e36819 Automatic Copyright Year update after running gdb/copyright.py
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.

For the avoidance of doubt, all changes in this commits were
performed by the script.
2022-01-01 19:13:23 +04:00
Simon Marchi
37260e0df0 gdb: re-format with black 21.12b0
Run black 21.12b0 on gdb/, there is a single whitespace change.  I will
update the wiki [1] in parallel to bump the version of black to 21.12b0.

[1] https://sourceware.org/gdb/wiki/Internals%20GDB-Python-Coding-Standards

Change-Id: Ib3b859e3506c74a4f15d16f1e44ef402de3b98e2
2021-12-15 20:30:53 -05:00
Andrew Burgess
2988a36005 gdb/python: Use tp_init instead of tp_new to setup gdb.Value
The documentation suggests that we implement gdb.Value.__init__,
however, this is not currently true, we really implement
gdb.Value.__new__.  This will cause confusion if a user tries to
sub-class gdb.Value.  They might write:

  class MyVal (gdb.Value):
      def __init__ (self, val):
          gdb.Value.__init__(self, val)

  obj = MyVal(123)
  print ("Got: %s" % obj)

But, when they source this code they'll see:

  (gdb) source ~/tmp/value-test.py
  Traceback (most recent call last):
    File "/home/andrew/tmp/value-test.py", line 7, in <module>
      obj = MyVal(123)
    File "/home/andrew/tmp/value-test.py", line 5, in __init__
      gdb.Value.__init__(self, val)
  TypeError: object.__init__() takes exactly one argument (the instance to initialize)
  (gdb)

The reason for this is that, as we don't implement __init__ for
gdb.Value, Python ends up calling object.__init__ instead, which
doesn't expect any arguments.

The Python docs suggest that the reason why we might take this
approach is because we want gdb.Value to be immutable:

   https://docs.python.org/3/c-api/typeobj.html#c.PyTypeObject.tp_new

But I don't see any reason why we should require gdb.Value to be
immutable when other types defined in GDB are not.  This current
immutability can be seen in this code:

  obj = gdb.Value(1234)
  print("Got: %s" % obj)
  obj.__init__ (5678)
  print("Got: %s" % obj)

Which currently runs without error, but prints:

  Got: 1234
  Got: 1234

In this commit I propose that we switch to using __init__ to
initialize gdb.Value objects.

This does introduce some additional complexity, during the __init__
call a gdb.Value might already be associated with a gdb value object,
in which case we need to cleanly break that association before
installing the new gdb value object.  However, the cost of doing this
is not great, and the benefit - being able to easily sub-class
gdb.Value seems worth it.

After this commit the first example above works without error, while
the second example now prints:

  Got: 1234
  Got: 5678

In order to make it easier to override the gdb.Value.__init__ method,
I have tweaked the definition of gdb.Value.__init__.  The second,
optional argument to __init__ is a gdb.Type, if this argument is not
present then GDB figures out a suitable type.

However, if we want to override the __init__ method in a sub-class,
and still support the default argument, it is easier to write:

  class MyVal (gdb.Value):
      def __init__ (self, val, type=None):
          gdb.Value.__init__(self, val, type)

Currently, passing None for the Type will result in an error:

  TypeError: type argument must be a gdb.Type.

After this commit I now allow the type argument to be None, in which
case GDB figures out a suitable type just as if the type had not been
passed at all.

Unless a user is trying to reinitialize a value, or create sub-classes
of gdb.Value, there should be no user visible changes after this
commit.
2021-12-08 13:38:11 +00:00
Andrew Burgess
90fe61ced1 gdb/python: don't use the 'p' format for parsing args
When running the gdb.python/py-arch.exp tests on a GDB built
against Python 2 I ran into some errors.  The problem is that this
test script exercises the gdb.Architecture.integer_type method, and
this method uses 'p' as an argument format specifier in a call to
gdb_PyArg_ParseTupleAndKeywords.

Unfortunately this specified was only added in Python 3.3, so will
cause an error for earlier versions of Python.

This commit switches to use the 'O' specifier to collect a PyObject,
and then uses PyObject_IsTrue to convert the object to a boolean.

An earlier version of this patch incorrectly switched from using 'p'
to use 'i', however, it was pointed out during review that this would
cause some changes in behaviour, for example both of these will work
with 'p', but not with 'i':

  gdb.selected_inferior().architecture().integer_type(32, None)
  gdb.selected_inferior().architecture().integer_type(32, "foo")

The new approach of using 'O' works fine with these cases.  I've added
some new tests to cover both of the above.

There should be no user visible changes after this commit.
2021-11-30 15:46:09 +00:00
Andrew Burgess
24b2de7b77 gdb/python: add gdb.RemoteTargetConnection.send_packet
This commits adds a new sub-class of gdb.TargetConnection,
gdb.RemoteTargetConnection.  This sub-class is created for all
'remote' and 'extended-remote' targets.

This new sub-class has one additional method over its base class,
'send_packet'.  This new method is equivalent to the 'maint
packet' CLI command, it allows a custom packet to be sent to a remote
target.

The outgoing packet can either be a bytes object, or a Unicode string,
so long as the Unicode string contains only ASCII characters.

The result of calling RemoteTargetConnection.send_packet is a bytes
object containing the reply that came from the remote.
2021-11-30 12:10:40 +00:00
Andrew Burgess
0e3b7c25ee gdb/python: introduce gdb.TargetConnection object type
This commit adds a new object type gdb.TargetConnection.  This new
type represents a connection within GDB (a connection as displayed by
'info connections').

There's three ways to find a gdb.TargetConnection, there's a new
'gdb.connections()' function, which returns a list of all currently
active connections.

Or you can read the new 'connection' property on the gdb.Inferior
object type, this contains the connection for that inferior (or None
if the inferior has no connection, for example, it is exited).

Finally, there's a new gdb.events.connection_removed event registry,
this emits a new gdb.ConnectionEvent whenever a connection is removed
from GDB (this can happen when all inferiors using a connection exit,
though this is not always the case, depending on the connection type).
The gdb.ConnectionEvent has a 'connection' property, which is the
gdb.TargetConnection being removed from GDB.

The gdb.TargetConnection has an 'is_valid()' method.  A connection
object becomes invalid when the underlying connection is removed from
GDB (as discussed above, this might be when all inferiors using a
connection exit, or it might be when the user explicitly replaces a
connection in GDB by issuing another 'target' command).

The gdb.TargetConnection has the following read-only properties:

  'num': The number for this connection,

  'type': e.g. 'native', 'remote', 'sim', etc

  'description': The longer description as seen in the 'info
                 connections' command output.

  'details': A string or None.  Extra details for the connection, for
             example, a remote connection's details might be
             'hostname:port'.
2021-11-30 12:10:33 +00:00
Enze Li
9e99facd6c gdb: ensure extension_language_python is always defined
In this commit:

  commit c6a6aad52d
  Date:   Mon Oct 25 17:25:45 2021 +0100

      gdb/python: make some global variables static

building without Python was broken.  The extension_language_python
global was moved from being always defined, to only being defined when
the HAVE_PYTHON macro was defined.  As a consequence, building without
Python support would result in errors like:

  /usr/bin/ld: extension.o:(.rodata+0x120): undefined reference to `extension_language_python'

This commit fixes the problem by moving the definition of
extension_language_python outside of the HAVE_PYTHON macro protection.
2021-11-25 18:05:46 +00:00
Andrew Burgess
c6a6aad52d gdb/python: make some global variables static
Make a couple of global variables static in python/python.c.  To do
this I had to move the definition of extension_language_python to
later in the file.

There should be no user visible changes after this commit.
2021-11-25 10:07:15 +00:00
Andrew Burgess
8579fd136a gdb/gdbsupport: make xstrprintf and xstrvprintf return a unique_ptr
The motivation is to reduce the number of places where unmanaged
pointers are returned from allocation type routines.  All of the
callers are updated.

There should be no user visible changes after this commit.
2021-11-16 17:45:45 +00:00
Simon Marchi
313f3b21cb gdb: remove bpstat typedef, rename bpstats to bpstat
I don't find that the bpstat typedef, which hides a pointer, is
particularly useful.  In fact, it confused me many times, and I just see
it as something to remember that adds cognitive load.  Also, with C++,
we might want to be able to pass bpstats objects by const-reference, not
necessarily by pointer.

So, remove the bpstat typedef and rename struct bpstats to bpstat (since
it represents one bpstat, it makes sense that it is singular).

Change-Id: I52e763b6e54ee666a9e045785f686d37b4f5f849
2021-11-08 16:39:14 -05:00
Simon Marchi
970db51860 gdb: remove TYPE_FIELD_ENUMVAL
Remove TYPE_FIELD_ENUMVAL, replace with type::field +
field::loc_enumval.

Change-Id: I2ada73e4635aad3363ce2eb22c1dc52698ee2072
2021-10-29 16:44:45 -04:00
Simon Marchi
b610c04548 gdb: remove TYPE_FIELD_BITPOS
Remove TYPE_FIELD_BITPOS, replace its uses with type::field +
field::loc_bitpos.

Change-Id: Iccd8d5a77e5352843a837babaa6bd284162e0320
2021-10-29 16:44:44 -04:00
Simon Marchi
2ad53ea10c gdb: remove TYPE_FIELD_LOC_KIND
Remove TYPE_FIELD_LOC_KIND, replace its uses with type::field +
field::loc_kind.

Change-Id: Ib124a26365df82ac1d23df7962d954192913bd90
2021-10-29 16:44:21 -04:00
Tom Tromey
d3771fe234 Add gdb.Architecture.integer_type Python function
This adds a new Python function, gdb.Architecture.integer_type, which
can be used to look up an integer type of a given size and
signed-ness.  This is useful to avoid dependency on debuginfo when a
particular integer type would be useful.

v2 moves this to be a method on gdb.Architecture and addresses other
review comments.
2021-10-29 07:52:31 -06:00
Simon Marchi
f54bdb6d27 gdb: add add_setshow_prefix_cmd
There's a common pattern to call add_basic_prefix_cmd and
add_show_prefix_cmd to add matching set and show commands.  Add the
add_setshow_prefix_cmd function to factor that out and use it at a few
places.

Change-Id: I6e9e90a30e9efb7b255bf839cac27b85d7069cfd
2021-10-28 10:44:18 -04:00
Simon Marchi
50888e42dc gdb: change functions returning value contents to use gdb::array_view
The bug fixed by this [1] patch was caused by an out-of-bounds access to
a value's content.  The code gets the value's content (just a pointer)
and then indexes it with a non-sensical index.

This made me think of changing functions that return value contents to
return array_views instead of a plain pointer.  This has the advantage
that when GDB is built with _GLIBCXX_DEBUG, accesses to the array_view
are checked, making bugs more apparent / easier to find.

This patch changes the return types of these functions, and updates
callers to call .data() on the result, meaning it's not changing
anything in practice.  Additional work will be needed (which can be done
little by little) to make callers propagate the use of array_view and
reap the benefits.

[1] https://sourceware.org/pipermail/gdb-patches/2021-September/182306.html

Change-Id: I5151f888f169e1c36abe2cbc57620110673816f3
2021-10-25 14:51:44 -04:00
Andrew Burgess
625f7b1cdc gdb/python: move gdb.Membuf support into a new file
In a future commit I'm going to be creating gdb.Membuf objects from a
new file within gdb/python/py*.c.  Currently all gdb.Membuf objects
are created directly within infpy_read_memory (as a result of calling
gdb.Inferior.read_memory()).

Initially I split out the Membuf creation code into a new function,
and left the new function in gdb/python/py-inferior.c, however, it
felt a little random that the Membuf creation code should live with
the inferior handling code.

So, then I moved all of the Membuf related code out into a new file,
gdb/python/py-membuf.c, the interface is gdbpy_buffer_to_membuf, which
wraps an array of bytes into a gdb.Membuf object.

Most of the code is moved directly from py-inferior.c with only minor
tweaks to layout and replacing NULL with nullptr, hence, I've left the
copyright date on py-membuf.c as 2009-2021 to match py-inferior.c.

Currently, the only user of this code is still py-inferior.c, but in
later commits this will change.

There should be no user visible changes after this commit.
2021-10-22 13:43:42 +01:00
Andrew Burgess
8b87fbe6bb gdb/python: new gdb.architecture_names function
Add a new function to the Python API, gdb.architecture_names().  This
function returns a list containing all of the supported architecture
names within the current build of GDB.

The values returned in this list are all of the possible values that
can be returned from gdb.Architecture.name().
2021-10-22 13:42:49 +01:00
Tom Tromey
6f781ee300 Use unique_xmalloc_ptr in breakpoint
This changes struct breakpoint to use unique_xmalloc_ptr in a couple
of spots, removing a bit of manual memory management.
2021-10-20 11:00:32 -06:00
Tom Tromey
a4c50be3d6 Use unique_xmalloc_ptr in watchpoint
This changes struct watchpoint to use unique_xmalloc_ptr in a couple
of places, removing a bit of manual memory management.
2021-10-20 11:00:31 -06:00
Tom de Vries
c82f680a94 [gdb/testsuite] Reimplement gdb.gdb/python-interrupts.exp as unittest
The test-case gdb.gdb/python-interrupts.exp:
- runs to captured_command_loop
- sets a breakpoint at set_active_ext_lang
- calls a python command
- verifies the command triggers the breakpoint
- sends a signal and verifies the result

The test-case is fragile, because (f.i. with -flto) it cannot be guaranteed
that captured_command_loop and set_active_ext_lang are available for setting
breakpoints.

Reimplement the test-case as unittest, using:
- execute_command_to_string to capture the output
- try/catch to catch the "Error while executing Python code" exception
- a new hook selftests::hook_set_active_ext_lang to raise the signal

Tested on x86_64-linux.
2021-10-19 23:50:50 +02:00
Tom de Vries
84a6adfd4c [gdb] Make execute_command_to_string return string on throw
The pattern for using execute_command_to_string is:
...
  std::string output;
  output = execute_fn_to_string (fn, term_out);
...

This results in a problem when using it in a try/catch:
...
  try
    {
      output = execute_fn_to_string (fn, term_out)
    }
  catch (const gdb_exception &e)
    {
      /* Use output.  */
    }
...

If an expection was thrown during execute_fn_to_string, then the output
remains unassigned, while it could be worthwhile to known what output was
generated by gdb before the expection was thrown.

Fix this by returning the string using a parameter instead:
...
  execute_fn_to_string (output, fn, term_out)
...

Also add a variant without string parameter, to support places where the
function is used while ignoring the result:
...
  execute_fn_to_string (fn, term_out)
...

Tested on x86_64-linux.
2021-10-09 18:58:30 +02:00