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
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.
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().
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.
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.
When a user creates a gdb.Inferior object for the first time a new
Python object is created. This object is then cached within GDB's
inferior object using the registry mechanism (see
inferior_to_inferior_object in py-inferior.c, specifically the calls
to inferior_data and set_inferior_data).
The Python Reference to the gdb.Inferior object held within the real
inferior object ensures that the reference count on the Python
gdb.Inferior object never reaches zero while the GDB inferior object
continues to exist.
At the same time, the gdb.Inferior object maintains a C++ pointer back
to GDB's real inferior object. We therefore end up with a system that
looks like this:
Python Reference
|
|
.----------. | .--------------.
| |------------------->| |
| inferior | | gdb.Inferior |
| |<-------------------| |
'----------' | '--------------'
|
|
C++ Pointer
When GDB's inferior object is deleted (say the inferior exits) then
py_free_inferior is called (thanks to the registry system), this
function looks up the Python gdb.Inferior object and sets the C++
pointer to nullptr and finally reduces the reference count on the
Python gdb.Inferior object.
If at this point the user still holds a reference to the Python
gdb.Inferior object then nothing happens. However, the gdb.Inferior
object is now in the non-valid state (see infpy_is_valid in
py-inferior.c), but otherwise, everything is fine.
However, if there are no further references to the Python gdb.Inferior
object, or, once the user has given up all their references to the
gdb.Inferior object, then infpy_dealloc is called.
This function currently checks to see if the inferior pointer within
the gdb.Inferior object is nullptr or not. If the pointer is nullptr
then infpy_dealloc immediately returns.
Only when the inferior point in the gdb.Inferior is not nullptr do
we (a) set the gdb.Inferior reference inside GDB's inferior to
nullptr, and (b) call the underlying Python tp_free function.
There are a number things wrong here:
1. The Python gdb.Inferior reference within GDB's inferior object
holds a reference count, thus, setting this reference to nullptr
without first decrementing the reference count would leak a
reference, however...
2. As GDB's inferior holds a reference then infpy_dealloc will never
be called until GDB's inferior object is deleted. Deleting a GDB
inferior ohject calls py_free_inferior, and so gives up the
reference. At this point there is no longer a need to call
set_inferior_data to set the field back to NULL, that field must
have been cleared in order to get the reference count to zero, which
means...
3. If we know that py_free_inferior must be called before
infpy_dealloc, then we know that the inferior pointer in
gdb.Inferior will always be nullptr when infpy_dealloc is called,
this means that the call to the underlying tp_free function will
always be skipped. Skipping this call will cause Python to leak the
memory associated with the gdb.Inferior object, which is what we
currently always do.
Given all of the above, I assert that the C++ pointer within
gdb.Inferior will always be nullptr when infpy_dealloc is called.
That's what this patch does.
I wrote a test for this issue making use of Pythons tracemalloc
module, which allows us to spot this memory leak.
Add a new event, gdb.events.gdb_exiting, which is called once GDB
decides it is going to exit.
This event is not triggered in the case that GDB performs a hard
abort, for example, when handling an internal error and the user
decides to quit the debug session, or if GDB hits an unexpected,
fatal, signal.
This event is triggered if the user just types 'quit' at the command
prompt, or if GDB is run with '-batch' and has processed all of the
required commands.
The new event type is gdb.GdbExitingEvent, and it has a single
attribute exit_code, which is the value that GDB is about to exit
with.
The event is triggered before GDB starts dismantling any of its own
internal state, so, my expectation is that most Python calls should
work just fine at this point.
When considering this functionality I wondered about using the
'atexit' Python module. However, this is triggered when the Python
environment is shut down, which is done from a final cleanup. At
this point we don't know for sure what other GDB state has already
been cleaned up.
String-like settings (var_string, var_filename, var_optional_filename,
var_string_noescape) currently take a pointer to a `char *` storage
variable (typically global) that holds the setting's value. I'd like to
"mordernize" this by changing them to use an std::string for storage.
An obvious reason is that string operations on std::string are often
easier to write than with C strings. And they avoid having to do any
manual memory management.
Another interesting reason is that, with `char *`, nullptr and an empty
string often both have the same meaning of "no value". String settings
are initially nullptr (unless initialized otherwise). But when doing
"set foo" (where `foo` is a string setting), the setting now points to
an empty string. For example, solib_search_path is nullptr at startup,
but points to an empty string after doing "set solib-search-path". This
leads to some code that needs to check for both to check for "no value".
Or some code that converts back and forth between NULL and "" when
getting or setting the value. I find this very error-prone, because it
is very easy to forget one or the other. With std::string, we at least
know that the variable is not "NULL". There is only one way of
representing an empty string setting, that is with an empty string.
I was wondering whether the distinction between NULL and "" would be
important for some setting, but it doesn't seem so. If that ever
happens, it would be more C++-y and self-descriptive to use
optional<string> anyway.
Actually, there's one spot where this distinction mattered, it's in
init_history, for the test gdb.base/gdbinit-history.exp. init_history
sets the history filename to the default ".gdb_history" if it sees that
the setting was never set - if history_filename is nullptr. If
history_filename is an empty string, it means the setting was explicitly
cleared, so it leaves it as-is. With the change to std::string, this
distinction doesn't exist anymore. This can be fixed by moving the code
that chooses a good default value for history_filename to
_initialize_top. This is ran before -ex commands are processed, so an
-ex command can then clear that value if needed (what
gdb.base/gdbinit-history.exp tests).
Another small improvement, in my opinion is that we can now easily
give string parameters initial values, by simply initializing the global
variables, instead of xstrdup-ing it in the _initialize function.
In Python and Guile, when registering a string-like parameter, we
allocate (with new) an std::string that is owned by the param_smob (in
Guile) and the parmpy_object (in Python) objects.
This patch started by changing all relevant add_setshow_* commands to
take an `std::string *` instead of a `char **` and fixing everything
that failed to build. That includes of course all string setting
variable and their uses.
string_option_def now uses an std::string also, because there's a
connection between options and settings (see
add_setshow_cmds_for_options).
The add_path function in source.c is really complex and twisted, I'd
rather not try to change it to work on an std::string right now.
Instead, I added an overload that copies the std:string to a `char *`
and back. This means more copying, but this is not used in a hot path
at all, so I think it is acceptable.
Change-Id: I92c50a1bdd8307141cdbacb388248e4e4fc08c93
Co-authored-by: Lancelot SIX <lsix@lancelotsix.com>
cmd_list_element can contain a pointer to data that can be set and / or
shown. This is achieved with the void* VAR member which points to the
data that can be accessed, while the VAR_TYPE member (of type enum
var_types) indicates how to interpret the data pointed to.
With this pattern, the user of the cmd_list_element needs to know what
is the storage type associated with a given VAR_TYPES in order to do
the proper casting. No automatic safeguard is available to prevent
miss-use of the pointer. Client code typically looks something like:
switch (c->var_type)
{
case var_zuinteger:
unsigned int v = *(unsigned int*) c->var;
...
break;
case var_boolean:
bool v = *(bool *) c->var;
...
break;
...
}
This patch proposes to add an abstraction around the var_types and void*
pointer pair. The abstraction is meant to prevent the user from having
to handle the cast and verify that the data is read or written as a type
that is coherent with the setting's var_type. This is achieved by
introducing the struct setting which exposes a set of templated get /
set member functions. The template parameter is the type of the
variable that holds the referred variable.
Using those accessors allows runtime checks to be inserted in order to
ensure that the data pointed to has the expected type. For example,
instantiating the member functions with bool will yield something
similar to:
const bool &get<bool> () const
{
gdb_assert (m_var_type == var_boolean);
gdb_assert (m_var != nullptr);
return *static_cast<bool *> (m_var);
}
void set<bool> (const bool &var)
{
gdb_assert (m_var_type == var_boolean);
gdb_assert (m_var != nullptr);
*static_cast<bool *> (m_var) = var;
}
Using the new abstraction, our initial example becomes:
switch (c->var_type)
{
case var_zuinteger:
unsigned int v = c->var->get<unsigned int> ();
...
break;
case var_boolean:
bool v = c->var->get<bool> ();
...
break;
...
}
While the call site is still similar, the introduction of runtime checks
help ensure correct usage of the data.
In order to avoid turning the bulk of add_setshow_cmd_full into a
templated function, and following a suggestion from Pedro Alves, a
setting can be constructed from a pre validated type erased reference to
a variable. This is what setting::erased_args is used for.
Introducing an opaque abstraction to describe a setting will also make
it possible to use callbacks to retrieve or set the value of the setting
on the fly instead of pointing to a static chunk of memory. This will
be done added in a later commit.
Given that a cmd_list_element may or may not reference a setting, the
VAR and VAR_TYPES members of the struct are replaced with a
gdb::optional<setting> named VAR.
Few internal function signatures have been modified to take into account
this new abstraction:
-The functions value_from_setting, str_value_from_setting and
get_setshow_command_value_string used to have a 'cmd_list_element *'
parameter but only used it for the VAR and VAR_TYPE member. They now
take a 'const setting &' parameter instead.
- Similarly, the 'void *' and a 'enum var_types' parameters of
pascm_param_value and gdbpy_parameter_value have been replaced with a
'const setting &' parameter.
No user visible change is expected after this patch.
Tested on GNU/Linux x86_64, with no regression noticed.
Co-authored-by: Simon Marchi <simon.marchi@polymtl.ca>
Change-Id: Ie1d08c3ceb8b30b3d7bf1efe036eb8acffcd2f34
Fix these rather obvious warnings reported by flake8:
./lib/gdb/FrameIterator.py:16:1: F401 'gdb' imported but unused
./lib/gdb/FrameIterator.py:17:1: F401 'itertools' imported but unused
./lib/gdb/command/prompt.py:55:26: E712 comparison to False should be 'if cond is False:' or 'if not cond:'
./lib/gdb/command/explore.py:526:9: F841 local variable 'has_explorable_fields' is assigned to but never used
./lib/gdb/command/explore.py:697:56: E712 comparison to False should be 'if cond is False:' or 'if not cond:'
./lib/gdb/command/explore.py:736:62: E712 comparison to False should be 'if cond is False:' or 'if not cond:'
./lib/gdb/command/explore.py:767:61: E712 comparison to False should be 'if cond is False:' or 'if not cond:'
./lib/gdb/command/frame_filters.py:21:1: F401 'copy' imported but unused
./lib/gdb/command/frame_filters.py:22:1: F401 'gdb.FrameIterator.FrameIterator' imported but unused
./lib/gdb/command/frame_filters.py:23:1: F401 'gdb.FrameDecorator.FrameDecorator' imported but unused
./lib/gdb/command/frame_filters.py:25:1: F401 'itertools' imported but unused
./lib/gdb/command/frame_filters.py:179:17: E712 comparison to True should be 'if cond is True:' or 'if cond:'
Change-Id: I4f49c0cb430359ee872222600c61d9c5283b09ab
Remove the `TYPE_FIELD_NAME` and `FIELD_NAME` macros, changing all the
call sites to use field::name directly.
Change-Id: I6900ae4e1ffab1396e24fb3298e94bf123826ca6
This started out as changing thread_info::name to a unique_xmalloc_ptr.
That showed that almost all users of that field had the same logic to
get a thread's name: use thread_info::name if non-nullptr, else ask the
target. Factor out this logic in a new thread_name free function. Make
the field private (rename to m_name) and add some accessors.
Change-Id: Iebdd95f4cd21fbefc505249bd1d05befc466a2fc
I noticed that pointer_type is declared in language.h and defined in
language.c. However, it really has to do with types, so it should
have been in gdbtypes.h all along.
This patch changes it to be a method on struct type. And, I went
through uses of TYPE_IS_REFERENCE and updated many spots to use the
new method as well. (I didn't update ones that were in arch-specific
code, as I couldn't readily test that.)
The ptid_t 'tid' member is normally used as an address in gdb -- both
bsd-uthread and ravenscar-thread use it this way. However, because
the type is 'long', this can cause problems with sign extension.
This patch changes the type to ULONGEST to ensure that sign extension
does not occur.
A build without Python will currently fail, because
selftests::test_python uses gdb_python_initialized, which is only
conditionally defined.
This patch fixes the build by making test_python also be conditionally
defined. I chose this approach because the selftest will fail if
Python is not enabled, so it didn't seem useful to leave it defined.
The test-case gdb.gdb/python-selftest.exp:
- patches the gdb_python_initialized variable in gdb to 0
- checks that the output of a python command is "Python not initialized"
Reimplement gdb.gdb/python-selftest.exp as unittest, using:
- execute_command_to_string to capture the output
- try/catch to catch the "Python not initialized" exception.
Tested on x86_64-linux.
Python 2 has a bit flag Py_TPFLAGS_HAVE_ITER which can be passed as
part of the tp_flags field when defining a new object type. This flag
is not defined in Python 3 and so we define it to 0 in
python-internal.h (when IS_PY3K is defined).
The meaning of this flag is that the object has the fields tp_iter and
tp_iternext. Note the use of "has" here, the flag says nothing about
the values in those fields, just that the type object has the fields.
In early versions of Python 2 these fields were no part of the
PyTypeObject struct, they were added in version 2.2 (see
https://docs.python.org/release/2.3/api/type-structs.html). And so,
there could be a some code compiled out there which has a PyTypeObject
structure within it that doesn't even have the tp_iter and tp_iternext
fields, attempting to access these fields would be undefined
behaviour.
And so Python added the Py_TPFLAGS_HAVE_ITER flag. If the flag is
present then Python is free to access the tp_iter and tp_iternext
fields.
If we consider GDB then we always assume that the tp_iter and
tp_iternext fields are part of PyTypeObject. If someone was crazy
enough to try and compile GDB against Python 2.1 then we'd get lots of
build errors saying that we were passing too many fields when
initializing PyTypeObject structures. And so, I claim, we can be sure
that GDB will always be compiled with a version of Python that has the
tp_iter and tp_iternext fields in PyTypeObject.
Next we can look at the Py_TPFLAGS_DEFAULT flag. In Python 2, each
time additional fields are added to PyTypeObject a new Py_TPFLAGS_*
flag would be defined to indicate whether those flags are present or
not. And, those new flags would be added to Py_TPFLAGS_DEFAULT. And
so, in the latest version of Python 2 the Py_TPFLAGS_DEFAULT flag
includes Py_TPFLAGS_HAVE_ITER (see
https://docs.python.org/2.7/c-api/typeobj.html).
In GDB we pass Py_TPFLAGS_DEFAULT as part of the tp_flags for all
objects we define.
And so, in this commit, I propose to remove all uses of
Py_TPFLAGS_HAVE_ITER from GDB, it's simply not needed.
There should be no user visible changes after this commit.
The guile API has (history-append! <value>) to add values into GDB's
history list. There is currently no equivalent in the Python API.
This commit adds gdb.add_history(<value>) to the Python API, this
function takes <value> a gdb.Value (or anything that can be passed to
the constructor of gdb.Value), and adds the value it represents to
GDB's history list. The index of the newly added value is returned.
I believe that many calls to fprintf_symbol_filtered are incorrect.
In particular, there are some that pass a symbol's print name, like:
fprintf_symbol_filtered (gdb_stdout, sym->print_name (),
current_language->la_language, DMGL_ANSI);
fprintf_symbol_filtered uses the "demangle" global to decide whether
or not to demangle -- but print_name does this as well. This can lead
to double-demangling. Normally this could be innocuous, except I also
plan to change Ada demangling in a way that causes this to fail.
I don't understand what the sfunc function type in
cmd_list_element::function is for. Compared to cmd_simple_func_ftype,
it has an extra cmd_list_element parameter, giving the callback access
to the cmd_list_element for the command being invoked. This allows
registering the same callback with many commands, and alter the behavior
using the cmd_list_element's context.
From the comment in cmd_list_element, it sounds like at some point it
was the callback function type for set and show functions, hence the
"s". But nowadays, it's used for many more commands that need to access
the cmd_list_element object (see add_catch_command for example).
I don't really see the point of having sfunc at all, since do_sfunc is
just a trivial shim that changes the order of the arguments. All
commands using sfunc could just as well set cmd_list_element::func to
their callback directly.
Therefore, remove the sfunc field in cmd_list_element and everything
that goes with it. Rename cmd_const_sfunc_ftype to cmd_func_ftype and
use it for cmd_list_element::func, as well as for the add_setshow
commands.
Change-Id: I1eb96326c9b511c293c76996cea0ebc51c70fac0
A following patch will want to take some action when a pending wait
status is set on or removed from a thread. Add a getter and a setter on
thread_info for the pending waitstatus, so that we can add some code in
the setter later.
The thing is, the pending wait status field is in the
thread_suspend_state, along with other fields that we need to backup
before and restore after the thread does an inferior function call.
Therefore, make the thread_suspend_state member private
(thread_info::suspend becomes thread_info::m_suspend), and add getters /
setters for all of its fields:
- pending wait status
- stop signal
- stop reason
- stop pc
For the pending wait status, add the additional has_pending_waitstatus
and clear_pending_waitstatus methods.
I think this makes the thread_info interface a bit nicer, because we
now access the fields as:
thread->stop_pc ()
rather than
thread->suspend.stop_pc
The stop_pc field being in the `suspend` structure is an implementation
detail of thread_info that callers don't need to be aware of.
For the backup / restore of the thread_suspend_state structure, add
save_suspend_to and restore_suspend_from methods. You might wonder why
`save_suspend_to`, as opposed to a simple getter like
thread_suspend_state &suspend ();
I want to make it clear that this is to be used only for backing up and
restoring the suspend state, _not_ to access fields like:
thread->suspend ()->stop_pc
Adding some getters / setters allows adding some assertions. I find
that this helps understand how things are supposed to work. Add:
- When getting the pending status (pending_waitstatus method), ensure
that there is a pending status.
- When setting a pending status (set_pending_waitstatus method), ensure
there is no pending status.
There is one case I found where this wasn't true - in
remote_target::process_initial_stop_replies - which needed adjustments
to respect that contract. I think it's because
process_initial_stop_replies is kind of (ab)using the
thread_info::suspend::waitstatus to store some statuses temporarily, for
its internal use (statuses it doesn't intent on leaving pending).
process_initial_stop_replies pulls out stop replies received during the
initial connection using target_wait. It always stores the received
event in `evthread->suspend.waitstatus`. But it only sets
waitstatus_pending_p, if it deems the event interesting enough to leave
pending, to be reported to the core:
if (ws.kind != TARGET_WAITKIND_STOPPED
|| ws.value.sig != GDB_SIGNAL_0)
evthread->suspend.waitstatus_pending_p = 1;
It later uses this flag a bit below, to choose which thread to make the
"selected" one:
if (selected == NULL
&& thread->suspend.waitstatus_pending_p)
selected = thread;
And ultimately that's used if the user-visible mode is all-stop, so that
we print the stop for that interesting thread:
/* In all-stop, we only print the status of one thread, and leave
others with their status pending. */
if (!non_stop)
{
thread_info *thread = selected;
if (thread == NULL)
thread = lowest_stopped;
if (thread == NULL)
thread = first;
print_one_stopped_thread (thread);
}
But in any case (all-stop or non-stop), print_one_stopped_thread needs
to access the waitstatus value of these threads that don't have a
pending waitstatus (those that had TARGET_WAITKIND_STOPPED +
GDB_SIGNAL_0). This doesn't work with the assertions I've
put.
So, change the code to only set the thread's wait status if it is an
interesting one that we are going to leave pending. If the thread
stopped due to a non-interesting event (TARGET_WAITKIND_STOPPED +
GDB_SIGNAL_0), don't store it. Adjust print_one_stopped_thread to
understand that if a thread has no pending waitstatus, it's because it
stopped with TARGET_WAITKIND_STOPPED + GDB_SIGNAL_0.
The call to set_last_target_status also uses the pending waitstatus.
However, given that the pending waitstatus for the thread may have been
cleared in print_one_stopped_thread (and that there might not even be a
pending waitstatus in the first place, as explained above), it is no
longer possible to do it at this point. To fix that, move the call to
set_last_target_status in print_one_stopped_thread. I think this will
preserve the existing behavior, because set_last_target_status is
currently using the current thread's wait status. And the current
thread is the last one for which print_one_stopped_thread is called. So
by calling set_last_target_status in print_one_stopped_thread, we'll get
the same result. set_last_target_status will possibly be called
multiple times, but only the last call will matter. It just means
possibly more calls to set_last_target_status, but those are cheap.
Change-Id: Iedab9653238eaf8231abcf0baa20145acc8b77a7
I wrote this while debugging a problem where the expected unwinder for a
frame wasn't used. It adds messages to show which unwinders are
considered for a frame, why they are not selected (if an exception is
thrown), and finally which unwinder is selected in the end.
To be able to show a meaningful, human-readable name for the unwinders,
add a "name" field to struct frame_unwind, and update all instances to
include a name.
Here's an example of the output:
[frame] frame_unwind_find_by_frame: this_frame=0
[frame] frame_unwind_try_unwinder: trying unwinder "dummy"
[frame] frame_unwind_try_unwinder: no
[frame] frame_unwind_try_unwinder: trying unwinder "dwarf2 tailcall"
[frame] frame_unwind_try_unwinder: no
[frame] frame_unwind_try_unwinder: trying unwinder "inline"
[frame] frame_unwind_try_unwinder: no
[frame] frame_unwind_try_unwinder: trying unwinder "jit"
[frame] frame_unwind_try_unwinder: no
[frame] frame_unwind_try_unwinder: trying unwinder "python"
[frame] frame_unwind_try_unwinder: no
[frame] frame_unwind_try_unwinder: trying unwinder "amd64 epilogue"
[frame] frame_unwind_try_unwinder: no
[frame] frame_unwind_try_unwinder: trying unwinder "i386 epilogue"
[frame] frame_unwind_try_unwinder: no
[frame] frame_unwind_try_unwinder: trying unwinder "dwarf2"
[frame] frame_unwind_try_unwinder: yes
gdb/ChangeLog:
* frame-unwind.h (struct frame_unwind) <name>: New. Update
instances everywhere to include this field.
* frame-unwind.c (frame_unwind_try_unwinder,
frame_unwind_find_by_frame): Add debug messages.
Change-Id: I813f17777422425f0d08b22499817b23922e8ddb
Following on from the previous commit, this commit changes the API of
value_struct_elt to take gdb::optional<gdb::array_view<value *>>
instead of a pointer to the gdb::array_view.
This makes the optional nature of the array_view parameter explicit.
This commit is purely a refactoring commit, there should be no user
visible change after this commit.
I have deliberately kept this refactor separate from the previous two
commits as this is a more extensive change, and I'm not 100% sure that
using gdb::optional for the parameter type, instead of a pointer, is
going to be to everyone's taste. If there's push back on this patch
then this one can be dropped from the series.
gdb/ChangeLog:
* ada-lang.c (desc_bounds): Use '{}' instead of NULL to indicate
an empty gdb::optional when calling value_struct_elt.
(desc_data): Likewise.
(desc_one_bound): Likewise.
* eval.c (structop_base_operation::evaluate_funcall): Pass
gdb::array_view, not a gdb::array_view* to value_struct_elt.
(eval_op_structop_struct): Use '{}' instead of NULL to indicate
an empty gdb::optional when calling value_struct_elt.
(eval_op_structop_ptr): Likewise.
* f-lang.c (fortran_structop_operation::evaluate): Likewise.
* guile/scm-value.c (gdbscm_value_field): Likewise.
* m2-lang.c (eval_op_m2_high): Likewise.
(eval_op_m2_subscript): Likewise.
* opencl-lang.c (opencl_structop_operation::evaluate): Likewise.
* python/py-value.c (valpy_getitem): Likewise.
* rust-lang.c (rust_val_print_str): Likewise.
(rust_range): Likewise.
(rust_subscript): Likewise.
(eval_op_rust_structop): Likewise.
(rust_aggregate_operation::evaluate): Likewise.
* valarith.c (value_user_defined_op): Likewise.
* valops.c (search_struct_method): Change parameter type, update
function body accordingly, and update header comment.
(value_struct_elt): Change parameter type, update function body
accordingly.
* value.h (value_struct_elt): Update declaration.
This commit adds initial support for catchpoints to the python
breakpoint API.
This commit adds a BP_CATCHPOINT constant which corresponds to
GDB's internal bp_catchpoint. The new constant is documented in the
manual.
The user can't create breakpoints with type BP_CATCHPOINT after this
commit, but breakpoints that already exist, obtained with the
`gdb.breakpoints` function, can now have this type. Additionally,
when a stop event is reported for hitting a catchpoint, GDB will now
report a BreakpointEvent with the attached breakpoint being of type
BP_CATCHPOINT - previously GDB would report a generic StopEvent in
this situation.
gdb/ChangeLog:
* NEWS: Mention Python BP_CATCHPOINT feature.
* python/py-breakpoint.c (pybp_codes): Add bp_catchpoint support.
(bppy_init): Likewise.
(gdbpy_breakpoint_created): Likewise.
gdb/doc/ChangeLog:
* python.texinfo (Breakpoints In Python): Add BP_CATCHPOINT
description.
gdb/testsuite/ChangeLog:
* gdb.python/py-breakpoint.c (do_throw): New function.
(main): Call do_throw.
* gdb.python/py-breakpoint.exp (test_catchpoints): New proc.
GNAT emits encoded type names, but these aren't usually of interest to
users. The Ada language code in gdb hides this oddity -- but the
Python layer does not. This patch changes the Python code to use the
decoded Ada type name, when appropriate.
I looked at decoding Ada type names during construction, as that would
be cleaner. However, the Ada support in gdb relies on the encodings
at various points, so this isn't really doable right now.
2021-06-25 Tom Tromey <tromey@adacore.com>
* python/py-type.c (typy_get_name): Decode an Ada type name.
gdb/testsuite/ChangeLog
2021-06-25 Tom Tromey <tromey@adacore.com>
* gdb.ada/py_range.exp: Add type name test cases.
If we have multiple registered unwinders, this will helps identify which
unwinder was chosen and make it easier to track down potential problems.
Unwinders have a mandatory name argument, which we can use in the
message.
First, make gdb._execute_unwinders return a tuple containing the name,
in addition to the UnwindInfo. Then, make pyuw_sniffer include the name
in the debug message.
I moved the debug message earlier. I think it's good to print it as
early as possible, so that we see it in case an assert is hit in the
loop below, for example.
gdb/ChangeLog:
* python/lib/gdb/__init__.py (_execute_unwinders): Return tuple
with name of chosen unwinder.
* python/py-unwind.c (pyuw_sniffer): Print name of chosen
unwinder in debug message.
Change-Id: Id603545b44a97df2a39dd1872fe1f38ad5059f03
Add new methods to the PendingFrame and Frame classes to obtain the
stack frame level for each object.
The use of 'level' as the method name is consistent with the existing
attribute RecordFunctionSegment.level (though this is an attribute
rather than a method).
For Frame/PendingFrame I went with methods as these classes currently
only use methods, including for simple data like architecture, so I
want to be consistent with this interface.
gdb/ChangeLog:
* NEWS: Mention the two new methods.
* python/py-frame.c (frapy_level): New function.
(frame_object_methods): Register 'level' method.
* python/py-unwind.c (pending_framepy_level): New function.
(pending_frame_object_methods): Register 'level' method.
gdb/doc/ChangeLog:
* python.texi (Unwinding Frames in Python): Mention
PendingFrame.level.
(Frames In Python): Mention Frame.level.
gdb/testsuite/ChangeLog:
* gdb.python/py-frame.exp: Add Frame.level tests.
* gdb.python/py-pending-frame-level.c: New file.
* gdb.python/py-pending-frame-level.exp: New file.
* gdb.python/py-pending-frame-level.py: New file.
We already have two helper functions in py-utils.c:
gdb_py_object_from_longest (LONGEST l)
gdb_py_object_from_ulongest (ULONGEST l)
these wrap around calls to either PyLong_FromLongLong,
PyLong_FromLong, or PyInt_From_Long (if Python 2 is being used).
There is one place in gdb/python/* where a call to PyLong_FromLong was
added outside of the above utility functions, this was done in the
recent commit:
commit 55789354fc
Date: Fri May 14 11:56:31 2021 +0200
gdb/python: add a 'connection_num' attribute to Inferior objects
In this commit I replace the direct use of PyLong_FromLong with a call
to gdb_py_object_from_longest. The only real change with this commit,
is that, for Python 2, we will now end up calling PyInt_FromLong
instead of PyLong_FromLong, but this should be invisible to the user.
For Python 3 there should be absolutely no change.
gdb/ChangeLog:
* python/py-inferior.c (infpy_get_connection_num): Call
gdb_py_object_from_longest instead of PyLong_FromLong directly.
This patch came about because I wanted to write a frame unwinder that
would corrupt the backtrace in a particular way. In order to achieve
what I wanted I ended up trying to write an unwinder like this:
class FrameId(object):
.... snip class definition ....
class TestUnwinder(Unwinder):
def __init__(self):
Unwinder.__init__(self, "some name")
def __call__(self, pending_frame):
pc_desc = pending_frame.architecture().registers().find("pc")
pc = pending_frame.read_register(pc_desc)
sp_desc = pending_frame.architecture().registers().find("sp")
sp = pending_frame.read_register(sp_desc)
# ... snip code to decide if this unwinder applies or not.
fid = FrameId(pc, sp)
unwinder = pending_frame.create_unwind_info(fid)
unwinder.add_saved_register(pc_desc, pc)
unwinder.add_saved_register(sp_desc, sp)
return unwinder
The important things here are the two calls:
unwinder.add_saved_register(pc_desc, pc)
unwinder.add_saved_register(sp_desc, sp)
On x86-64 these would fail with an assertion error:
gdb/regcache.c:168: internal-error: int register_size(gdbarch*, int): Assertion `regnum >= 0 && regnum < gdbarch_num_cooked_regs (gdbarch)' failed.
What happens is that in unwind_infopy_add_saved_register (py-unwind.c)
we call register_size, as register_size should only be called on
cooked (real or pseudo) registers, and 'pc' and 'sp' are implemented
as user registers (at least on x86-64), we trigger the assertion.
A simple fix would be to check in unwind_infopy_add_saved_register if
the register number we are handling is a cooked register or not, if
not we can throw a 'Bad register' error back to the Python code.
However, I think we can do better.
Consider that at the CLI we can do this:
(gdb) set $pc=0x1234
This works because GDB first evaluates '$pc' to get a register value,
then evaluates '0x1234' to create a value encapsulating the
immediate. The contents of the immediate value are then copied back
to the location of the register value representing '$pc'.
The value location for a user-register will (usually) be the location
of the real register that was accessed, so on x86-64 we'd expect this
to be $rip.
So, in this patch I propose that in the unwinder code, when
add_saved_register is called, if it is passed a
user-register (i.e. non-cooked) then we first fetch the register,
extract the real register number from the value's location, and use
that new register number when handling the add_saved_register call.
If either the value location that we get for the user-register is not
a cooked register then we can throw a 'Bad register' error back to the
Python code, but in most cases this will not happen.
gdb/ChangeLog:
* python/py-unwind.c (unwind_infopy_add_saved_register): Handle
saving user registers.
gdb/testsuite/ChangeLog:
* gdb.python/py-unwind-user-regs.c: New file.
* gdb.python/py-unwind-user-regs.exp: New file.
* gdb.python/py-unwind-user-regs.py: New file.
While reviewing a patch sent to the mailing list, I noticed there are few
places where python code checks if a variable is 'None' or not by using the
comparison operators '==' and '!='. PEP8[1], which is used as coding standard
in GDB coding standards, recommends using 'is' / 'is not' when comparing to a
singleton such as 'None'.
This patch proposes to change the instances of '== None' by 'is None' and
'!= None' by 'is not None'.
[1] https://www.python.org/dev/peps/pep-0008/
gdb/doc/ChangeLog:
* python.texi (Writing a Pretty-Printer): Use 'is None' instead of
'== None'.
gdb/ChangeLog:
* python/lib/gdb/FrameDecorator.py (FrameDecorator): Use 'is None' instead of
'== None'.
(FrameVars): Use 'is not None' instead of '!= None'.
* python/lib/gdb/command/frame_filters.py (SetFrameFilterPriority): Use 'is None'
instead of '== None' and 'is not None' instead of '!= None'.
gdb/testsuite/ChangeLog:
* gdb.base/premature-dummy-frame-removal.py (TestUnwinder): Use
'is None' instead of '== None' and 'is not None' instead of
'!= None'.
* gdb.python/py-frame-args.py (lookup_function): Same.
* gdb.python/py-framefilter-invalidarg.py (Reverse_Function): Same.
* gdb.python/py-framefilter.py (Reverse_Function): Same.
* gdb.python/py-nested-maps.py (lookup_function): Same.
* gdb.python/py-objfile-script-gdb.py (lookup_function): Same.
* gdb.python/py-prettyprint.py (lookup_function): Same.
* gdb.python/py-section-script.py (lookup_function): Same.
* gdb.python/py-unwind-inline.py (dummy_unwinder): Same.
* gdb.python/python.exp: Same.
* gdb.rust/pp.py (lookup_function): Same.
If the TUI window object implements the click method, it is called for each
mouse click event in this window.
gdb/ChangeLog:
2021-06-04 Hannes Domani <ssbssa@yahoo.de>
* python/py-tui.c (class tui_py_window): Add click function.
(tui_py_window::click): Likewise.
gdb/doc/ChangeLog:
2021-06-04 Hannes Domani <ssbssa@yahoo.de>
* python.texi (TUI Windows In Python): Document Window.click.
It was removed (probably by mistake) in
51e78fc5fa.
gdb/ChangeLog:
2021-06-03 Hannes Domani <ssbssa@yahoo.de>
* python/py-symbol.c (gdbpy_initialize_symbols): Restore
gdb.SYMBOL_LABEL_DOMAIN constant.
gdb/testsuite/ChangeLog:
2021-06-03 Hannes Domani <ssbssa@yahoo.de>
* gdb.python/py-symbol.exp: Test symbol constants.
I wrote a small script to spot a pattern of indentation mistakes I saw
happened in breakpoint.c. And while at it I ran it on all files and
fixed what I found. No behavior changes intended, just indentation and
addition / removal of curly braces.
gdb/ChangeLog:
* Fix some indentation mistakes throughout.
gdbserver/ChangeLog:
* Fix some indentation mistakes throughout.
Change-Id: Ia01990c26c38e83a243d8f33da1d494f16315c6e
Now that we have range functions that let us use ranged for loops, we
can remove iterate_over_breakpoints in favor of those, which are easier
to read and write. This requires exposing the declaration of
all_breakpoints and all_breakpoints_safe in breakpoint.h, as well as the
supporting types.
Change some users of iterate_over_breakpoints to use all_breakpoints,
when they don't need to delete the breakpoint, and all_breakpoints_safe
otherwise.
gdb/ChangeLog:
* breakpoint.h (iterate_over_breakpoints): Remove. Update
callers to use all_breakpoints or all_breakpoints_safe.
(breakpoint_range, all_breakpoints, breakpoint_safe_range,
all_breakpoints_safe): Move here.
* breakpoint.c (all_breakpoints, all_breakpoints_safe): Make
non-static.
(iterate_over_breakpoints): Remove.
* python/py-finishbreakpoint.c (bpfinishpy_detect_out_scope_cb):
Return void.
* python/py-breakpoint.c (build_bp_list): Add comment, reverse
return value logic.
* guile/scm-breakpoint.c (bpscm_build_bp_list): Return void.
Change-Id: Idde764a1f577de0423e4f2444a7d5cdb01ba5e48
To prevent flickering when first calling erase, then write, this new
argument indicates that the passed string contains the full contents of
the window. This fills every unused cell of the window with a space, so
it's not necessary to call erase beforehand.
gdb/ChangeLog:
2021-05-27 Hannes Domani <ssbssa@yahoo.de>
* python/py-tui.c (tui_py_window::output): Add full_window
argument.
(gdbpy_tui_write): Parse "full_window" argument.
gdb/doc/ChangeLog:
2021-05-27 Hannes Domani <ssbssa@yahoo.de>
* python.texi (TUI Windows In Python): Document "full_window"
argument.
The alias creation functions currently accept a name to specify the
target command. They pass this to add_alias_cmd, which needs to lookup
the target command by name.
Given that:
- We don't support creating an alias for a command before that command
exists.
- We always use add_info_alias just after creating that target command,
and therefore have access to the target command's cmd_list_element.
... change add_com_alias to accept the target command as a
cmd_list_element (other functions are done in subsequent patches). This
ensures we don't create the alias before the target command, because you
need to get the cmd_list_element from somewhere when you call the alias
creation function. And it avoids an unecessary command lookup. So it
seems better to me in every aspect.
gdb/ChangeLog:
* command.h (add_com_alias): Accept target as
cmd_list_element. Update callers.
Change-Id: I24bed7da57221cc77606034de3023fedac015150
In add_setshow_generic, we create set/show commands using add_setshow_*
functions, then look up the commands by name to set the context pointer.
It would be simpler and more efficient to use the return values of the
add_setshow_* functions, do that.
gdb/ChangeLog:
* python/py-param.c (add_setshow_generic): Use return values of
add_setshow functions.
Change-Id: I04d50736e1001ddb732d81e088468876df9c88ff
Remove a few instances where we look up a command by name, but could
just use the return value of a previous "add command" function call
instead.
gdb/ChangeLog:
* mi/mi-main.c (_initialize_mi_main):
* python/py-auto-load.c (gdbpy_initialize_auto_load):
* remote.c (_initialize_remote):
Change-Id: I6d06f9ca636e340c88c1064ae870483ad392607d
tui_win_info::refresh_window first redraws the background window, then
tui_wrefresh draws the python text on top of it, which flickers.
By using wnoutrefresh for the background window, the actual drawing on
the screen is only done once, without flickering.
gdb/ChangeLog:
2021-05-24 Hannes Domani <ssbssa@yahoo.de>
* python/py-tui.c (tui_py_window::refresh_window):
Avoid flickering.
Same idea as the previous patch, but for prefix instead of alias.
gdb/ChangeLog:
* cli/cli-decode.h (cmd_list_element) <is_prefix>: New, use it.
Change-Id: I76a9d2e82fc8d7429904424674d99ce6f9880e2b
While browsing this code, I found the name "prefixlist" really
confusing. I kept reading it as "list of prefixes". Which it isn't:
it's a list of sub-commands, for a prefix command. I think that
renaming it to "subcommands" would make things clearer.
gdb/ChangeLog:
* Rename "prefixlist" parameters to "subcommands" throughout.
* cli/cli-decode.h (cmd_list_element) <prefixlist>: Rename to...
<subcommands>: ... this.
* cli/cli-decode.c (lookup_cmd_for_prefixlist): Rename to...
(lookup_cmd_with_subcommands): ... this.
Change-Id: I150da10d03052c2420aa5b0dee41f422e2a97928
Define a 'connection_num' attribute for Inferior objects. The
read-only attribute is the ID of the connection of an inferior, as
printed by "info inferiors". In GDB's internal terminology, that's
the process stratum target of the inferior. If the inferior has no
target connection, the attribute is None.
gdb/ChangeLog:
2021-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* python/py-inferior.c (infpy_get_connection_num): New function.
(inferior_object_getset): Add a new element for 'connection_num'.
* NEWS: Mention the 'connection_num' attribute of Inferior objects.
gdb/doc/ChangeLog:
2021-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* python.texi (Inferiors In Python): Mention the 'connection_num'
attribute.
gdb/testsuite/ChangeLog:
2021-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* gdb.python/py-inferior.exp: Add test cases for 'connection_num'.
The 'print max-depth' feature incorrectly causes GDB to skip printing
the string representation of pretty printed variables if the variable
is stored at a nested depth corresponding to the set max-depth value.
This change ensures that it is always printed before checking whether
the maximum print depth has been reached.
Regression tested with GCC 7.3.0 on x86_64, ppc64le, aarch64.
gdb/ChangeLog:
* cp-valprint.c (cp_print_value): Replaced duplicate code.
* guile/scm-pretty-print.c (ppscm_print_children): Check max_depth
just before printing child values.
(gdbscm_apply_val_pretty_printer): Don't check max_depth before
printing string representation.
* python/py-prettyprint.c (print_children): Check max_depth just
before printing child values.
(gdbpy_apply_val_pretty_printer): Don't check max_depth before
printing string representation.
gdb/testsuite/ChangeLog:
* gdb.python/py-format-string.c: Added a variable to test.
* gdb.python/py-format-string.exp: Check string representation is
printed at appropriate max_depth settings.
* gdb.python/py-nested-maps.exp: Likewise.
* gdb.guile/scm-pretty-print.exp: Add additional tests.
This avoids some manual memory management.
cmdpy_init correctly transfers ownership of the name to the
cmd_list_element, as it sets the name_allocated flag. However,
cmdpy_init (and add_setshow_generic) doesn't, it looks like the name is
just leaked. This is a bit tricky, because it actually creates two
commands (one set and one show), it would take a bit of refactoring of
the command code to give each their own allocated copy. For now, just
keep doing what the current code does but in a more explicit fashion,
with an explicit release.
gdb/ChangeLog:
* python/python-internal.h (gdbpy_parse_command_name): Return
gdb::unique_xmalloc_ptr.
* python/py-cmd.c (gdbpy_parse_command_name): Likewise.
(cmdpy_init): Adjust.
* python/py-param.c (parmpy_init): Adjust.
(add_setshow_generic): Take gdb::unique_xmalloc_ptr, release it
when done.
Change-Id: Iae5bc21fe2b22f12d5f954057b0aca7ca4cd3f0d
Previously, the prefixname field of struct cmd_list_element was manually
set for prefix commands. This seems verbose and error prone as it
required every single call to functions adding prefix commands to
specify the prefix name while the same information can be easily
generated.
Historically, this was not possible as the prefix field was null for
many commands, but this was fixed in commit
3f4d92ebdf by Philippe Waroquiers, so
we can rely on the prefix field being set when generating the prefix
name.
This commit also fixes a use after free in this scenario:
* A command gets created via Python (using the gdb.Command class).
The prefix name member is dynamically allocated.
* An alias to the new command is created. The alias's prefixname is set
to point to the prefixname for the original command with a direct
assignment.
* A new command with the same name as the Python command is created.
* The object for the original Python command gets freed and its
prefixname gets freed as well.
* The alias is updated to point to the new command, but its prefixname
is not updated so it keeps pointing to the freed one.
gdb/ChangeLog:
* command.h (add_prefix_cmd): Remove the prefixname argument as
it can now be generated automatically. Update all callers.
(add_basic_prefix_cmd): Ditto.
(add_show_prefix_cmd): Ditto.
(add_prefix_cmd_suppress_notification): Ditto.
(add_abbrev_prefix_cmd): Ditto.
* cli/cli-decode.c (add_prefix_cmd): Ditto.
(add_basic_prefix_cmd): Ditto.
(add_show_prefix_cmd): Ditto.
(add_prefix_cmd_suppress_notification): Ditto.
(add_prefix_cmd_suppress_notification): Ditto.
(add_abbrev_prefix_cmd): Ditto.
* cli/cli-decode.h (struct cmd_list_element): Replace the
prefixname member variable with a method which generates the
prefix name at runtime. Update all code reading the prefix
name to use the method, and remove all code setting it.
* python/py-cmd.c (cmdpy_destroyer): Remove code to free the
prefixname member as it's now a method.
(cmdpy_function): Determine if the command is a prefix by
looking at prefixlist, not prefixname.
