Within the breakpoint struct we have two fields ::thread and ::task
which are used for thread or task specific breakpoints. When a
breakpoint doesn't have a specific thread or task then these fields
have the values -1 and 0 respectively.
There's no particular reason (as far as I can tell) why these two
"default" values are different, and I find the difference a little
confusing. Long term I'd like to potentially fold these two fields
into a single field, but that isn't what this commit does.
What this commit does is switch to using -1 as the "default" value for
both fields, this means that the default for breakpoint::task has
changed from 0 to -1. I've updated all the code I can find that
relied on the value of 0, and I see no test regressions, especially in
gdb.ada/tasks.exp, which still fully passes.
There should be no user visible changes after this commit.
Approved-By: Pedro Alves <pedro@palves.net>
After this mailing list posting:
https://sourceware.org/pipermail/gdb-patches/2023-February/196607.html
it seems to me that in practice an Ada task maps 1:1 with a GDB
thread, and so it doesn't really make sense to allow uses to give both
a thread and a task within a single breakpoint or watchpoint
condition.
This commit updates GDB so that the user will get an error if both
are specified.
I've added new tests to cover the CLI as well as the Python and Guile
APIs. For the Python and Guile testing, as far as I can tell, this
was the first testing for this corner of the APIs, so I ended up
adding more than just a single test.
For documentation I've added a NEWS entry, but I've not added anything
to the docs themselves. Currently we document the commands with a
thread-id or task-id as distinct command, e.g.:
'break LOCSPEC task TASKNO'
'break LOCSPEC task TASKNO if ...'
'break LOCSPEC thread THREAD-ID'
'break LOCSPEC thread THREAD-ID if ...'
As such, I don't believe there is any indication that combining 'task'
and 'thread' would be expected to work; it seems clear to me in the
above that those four options are all distinct commands.
I think the NEWS entry is enough that if someone is combining these
keywords (it's not clear what the expected behaviour would be in this
case) then they can figure out that this was a deliberate change in
GDB, but for a new user, the manual doesn't suggest combining them is
OK, and any future attempt to combine them will give an error.
Approved-By: Pedro Alves <pedro@palves.net>
A following patch will want to install a breakpoint and then keep a
non-owning reference to it. Make install_breakpoint return a non-owning
reference, to make that easy.
Co-Authored-By: Simon Marchi <simon.marchi@efficios.com>
Change-Id: I2e8106a784021ff276ce251e24708cbdccc2d479
Approved-By: Andrew Burgess <aburgess@redhat.com>
This commit is the result of running the gdb/copyright.py script,
which automated the update of the copyright year range for all
source files managed by the GDB project to be updated to include
year 2023.
This implements the request given in PR breakpoints/12464.
Before this patch, when a breakpoint that has multiple locations is reached,
GDB printed:
Thread 1 "zeoes" hit Breakpoint 1, some_func () at somefunc1.c:5
This patch changes the message so that bkpt_print_id prints the precise
encountered breakpoint:
Thread 1 "zeoes" hit Breakpoint 1.2, some_func () at somefunc1.c:5
In mi mode, bkpt_print_id also (optionally) prints a new table field "locno":
locno is printed when the breakpoint hit has more than one location.
Note that according to the GDB user manual node 'GDB/MI Development and Front
Ends', it is ok to add new fields without changing the MI version.
Also, when a breakpoint is reached, the convenience variables
$_hit_bpnum and $_hit_locno are set to the encountered breakpoint number
and location number.
$_hit_bpnum and $_hit_locno can a.o. be used in the command list of a
breakpoint, to disable the specific encountered breakpoint, e.g.
disable $_hit_bpnum.$_hit_locno
In case the breakpoint has only one location, $_hit_locno is set to
the value 1, so as to allow a command such as:
disable $_hit_bpnum.$_hit_locno
to disable the breakpoint even when the breakpoint has only one location.
This also fixes a strange behaviour: when a breakpoint X has only
one location,
enable|disable X.1
is accepted but transforms the breakpoint in a multiple locations
breakpoint having only one location.
The changes in RFA v4 handle the comments of Tom Tromey:
- Changed convenience var names from $bkptno/$locno to
$_hit_bpnum/$_hit_locno.
- updated the tests and user manual accordingly.
User manual also explictly describes that $_hit_locno is set to 1
for a breakpoint with a single location.
- The variable values are now set in bpstat_do_actions_1 so that
they are set for silent breakpoints, and when several breakpoints
are hit at the same time, that the variables are set to the printed
breakpoint.
The changes in RFA v3 handle the additional comments of Eli:
GDB/NEW:
- Use max 80-column
- Use 'code location' instead of 'location'.
- Fix typo $bkpno
- Ensure that disable $bkptno and disable $bkptno.$locno have
each their explanation inthe example
- Reworded the 'breakpoint-hit' paragraph.
gdb.texinfo:
- Use 'code location' instead of 'location'.
- Add a note to clarify the distinction between $bkptno and $bpnum.
- Use @kbd instead of examples with only one command.
Compared to RFA v1, the changes in v2 handle the comments given by
Keith Seitz and Eli Zaretskii:
- Use %s for the result of paddress
- Use bkptno_numopt_re instead of 2 different -re cases
- use C@t{++}
- Add index entries for $bkptno and $locno
- Added an example for "locno" in the mi interface
- Added examples in the Break command manual.
The print_one_detail_ranged_breakpoint has been renamed to
ranged_breakpoint::print_one_detail in this commit:
commit ec45bb676c9c69c30783bcf35ffdac8280f3b8bc
Date: Sat Jan 15 16:34:51 2022 -0700
Convert ranged breakpoints to vtable ops
So their comments should be updated as well.
Change from int to target_waitkind, which is really what is is. While
at it, remove some outdated doc. The return value is described by a
relatively self-describing enum, not a numerical value like the doc
says.
Change-Id: Id899c853a857c7891c45e5b1639024067d5b59cd
breakpoint::decode_location_spec just asserts if called. It turned
out to be relatively easy to remove this method from breakpoint and
instead move the base implementation to code_breakpoint.
The "script" field, output whenever information about a breakpoint with
commands is output, uses wrong MI syntax.
$ ./gdb -nx -q --data-directory=data-directory -x script -i mi
=thread-group-added,id="i1"
=breakpoint-created,bkpt={number="1",type="breakpoint",disp="keep",enabled="y",addr="0x000000000000111d",func="main",file="test.c",fullname="/home/simark/build/binutils-gdb-one-target/gdb/test.c",line="3",thread-groups=["i1"],times="0",original-location="main"}
=breakpoint-modified,bkpt={number="1",type="breakpoint",disp="keep",enabled="y",addr="0x000000000000111d",func="main",file="test.c",fullname="/home/simark/build/binutils-gdb-one-target/gdb/test.c",line="3",thread-groups=["i1"],times="0",script={"aaa","bbb","ccc"},original-location="main"}
(gdb)
-break-info
^done,BreakpointTable={nr_rows="1",nr_cols="6",hdr=[{width="7",alignment="-1",col_name="number",colhdr="Num"},{width="14",alignment="-1",col_name="type",colhdr="Type"},{width="4",alignment="-1",col_name="disp",colhdr="Disp"},{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},{width="18",alignment="-1",col_name="addr",colhdr="Address"},{width="40",alignment="2",col_name="what",colhdr="What"}],body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",addr="0x000000000000111d",func="main",file="test.c",fullname="/home/simark/build/binutils-gdb-one-target/gdb/test.c",line="3",thread-groups=["i1"],times="0",script={"aaa","bbb","ccc"},original-location="main"}]}
(gdb)
In both the =breakpoint-modified and -break-info output, we have:
script={"aaa","bbb","ccc"}
According to the output syntax [1], curly braces means tuple, and a
tuple contains key=value pairs. This looks like it should be a list,
but uses curly braces by mistake. This would make more sense:
script=["aaa","bbb","ccc"]
Fix it, keeping the backwards compatibility by introducing a new MI
version (MI4), in exactly the same way as was done when fixing
multi-locations breakpoint output in [2].
- Add a fix_breakpoint_script_output uiout flag. MI uiouts will use
this flag if the version is >= 4.
- Add a fix_breakpoint_script_output_globally variable and the
-fix-breakpoint-script-output MI command to set it, if frontends want
to use the fixed output for this without using the newer MI version.
- When emitting the script field, use list instead of tuple, if we want
the fixed output (depending on the two criteria above)
-
[1] https://sourceware.org/gdb/onlinedocs/gdb/GDB_002fMI-Output-Syntax.html#GDB_002fMI-Output-Syntax
[2] b4be1b0648
Change-Id: I7113c6892832c8d6805badb06ce42496677e2242
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=24285
PR python/18385
v7:
This version addresses the issues pointed out by Tom.
Added nullchecks for Python object creations.
Changed from using PyLong_FromLong to the gdb_py-versions.
Re-factored some code to make it look more cohesive.
Also added the more safe Python reference count decrement PY_XDECREF,
even though the BreakpointLocation type is never instantiated by the
user (explicitly documented in the docs) decrementing < 0 is made
impossible with the safe call.
Tom pointed out that using the policy class explicitly to decrement a
reference counted object was not the way to go, so this has instead been
wrapped in a ref_ptr that handles that for us in blocpy_dealloc.
Moved macro from py-internal to py-breakpoint.c.
Renamed section at the bottom of commit message "Patch Description".
v6:
This version addresses the points Pedro gave in review to this patch.
Added the attributes `function`, `fullname` and `thread_groups`
as per request by Pedro with the argument that it more resembles the
output of the MI-command "-break-list". Added documentation for these attributes.
Cleaned up left overs from copy+paste in test suite, removed hard coding
of line numbers where possible.
Refactored some code to use more c++-y style range for loops
wrt to breakpoint locations.
Changed terminology, naming was very inconsistent. Used a variety of "parent",
"owner". Now "owner" is the only term used, and the field in the
gdb_breakpoint_location_object now also called "owner".
v5:
Changes in response to review by Tom Tromey:
- Replaced manual INCREF/DECREF calls with
gdbpy_ref ptrs in places where possible.
- Fixed non-gdb style conforming formatting
- Get parent of bploc increases ref count of parent.
- moved bploc Python definition to py-breakpoint.c
The INCREF of self in bppy_get_locations is due
to the individual locations holding a reference to
it's owner. This is decremented at de-alloc time.
The reason why this needs to be here is, if the user writes
for instance;
py loc = gdb.breakpoints()[X].locations[Y]
The breakpoint owner object is immediately going
out of scope (GC'd/dealloced), and the location
object requires it to be alive for as long as it is alive.
Thanks for your review, Tom!
v4:
Fixed remaining doc issues as per request
by Eli.
v3:
Rewritten commit message, shortened + reworded,
added tests.
Patch Description
Currently, the Python API lacks the ability to
query breakpoints for their installed locations,
and subsequently, can't query any information about them, or
enable/disable individual locations.
This patch solves this by adding Python type gdb.BreakpointLocation.
The type is never instantiated by the user of the Python API directly,
but is produced by the gdb.Breakpoint.locations attribute returning
a list of gdb.BreakpointLocation.
gdb.Breakpoint.locations:
The attribute for retrieving the currently installed breakpoint
locations for gdb.Breakpoint. Matches behavior of
the "info breakpoints" command in that it only
returns the last known or currently inserted breakpoint locations.
BreakpointLocation contains 7 attributes
6 read-only attributes:
owner: location owner's Python companion object
source: file path and line number tuple: (string, long) / None
address: installed address of the location
function: function name where location was set
fullname: fullname where location was set
thread_groups: thread groups (inferiors) where location was set.
1 writeable attribute:
enabled: get/set enable/disable this location (bool)
Access/calls to these, can all throw Python exceptions (documented in
the online documentation), and that's due to the nature
of how breakpoint locations can be invalidated
"behind the scenes", either by them being removed
from the original breakpoint or changed,
like for instance when a new symbol file is loaded, at
which point all breakpoint locations are re-created by GDB.
Therefore this patch has chosen to be non-intrusive:
it's up to the Python user to re-request the locations if
they become invalid.
Also there's event handlers that handle new object files etc, if a Python
user is storing breakpoint locations in some larger state they've
built up, refreshing the locations is easy and it only comes
with runtime overhead when the Python user wants to use them.
gdb.BreakpointLocation Python type
struct "gdbpy_breakpoint_location_object" is found in python-internal.h
Its definition, layout, methods and functions
are found in the same file as gdb.Breakpoint (py-breakpoint.c)
1 change was also made to breakpoint.h/c to make it possible
to enable and disable a bp_location* specifically,
without having its LOC_NUM, as this number
also can change arbitrarily behind the scenes.
Updated docs & news file as per request.
Testsuite: tests the .source attribute and the disabling of
individual locations.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=18385
Change-Id: I302c1c50a557ad59d5d18c88ca19014731d736b0
Currently, GDB internally uses the term "location" for both the
location specification the user input (linespec, explicit location, or
an address location), and for actual resolved locations, like the
breakpoint locations, or the result of decoding a location spec to
SaLs. This is expecially confusing in the breakpoints module, as
struct breakpoint has these two fields:
breakpoint::location;
breakpoint::loc;
"location" is the location spec, and "loc" is the resolved locations.
And then, we have a method called "locations()", which returns the
resolved locations as range...
The location spec type is presently called event_location:
/* Location we used to set the breakpoint. */
event_location_up location;
and it is described like this:
/* The base class for all an event locations used to set a stop event
in the inferior. */
struct event_location
{
and even that is incorrect... Location specs are used for finding
actual locations in the program in scenarios that have nothing to do
with stop events. E.g., "list" works with location specs.
To clean all this confusion up, this patch renames "event_location" to
"location_spec" throughout, and then all the variables that hold a
location spec, they are renamed to include "spec" in their name, like
e.g., "location" -> "locspec". Similarly, functions that work with
location specs, and currently have just "location" in their name are
renamed to include "spec" in their name too.
Change-Id: I5814124798aa2b2003e79496e78f95c74e5eddca
Even after the previous patches reworking the inheritance of several
breakpoint types, the present breakpoint hierarchy looks a bit
surprising, as we have "breakpoint" as the superclass, and then
"base_breakpoint" inherits from "breakpoint". Like so, simplified:
breakpoint
base_breakpoint
ordinary_breakpoint
internal_breakpoint
momentary_breakpoint
ada_catchpoint
exception_catchpoint
tracepoint
watchpoint
catchpoint
exec_catchpoint
...
The surprising part to me is having "base_breakpoint" being a subclass
of "breakpoint". I'm just refering to naming here -- I mean, you'd
expect that it would be the top level baseclass that would be called
"base".
Just flipping the names of breakpoint and base_breakpoint around
wouldn't be super great for us, IMO, given we think of every type of
*point as a breakpoint at the user visible level. E.g., "info
breakpoints" shows watchpoints, tracepoints, etc. So it makes to call
the top level class breakpoint.
Instead, I propose renaming base_breakpoint to code_breakpoint. The
previous patches made sure that all code breakpoints inherit from
base_breakpoint, so it's fitting. Also, "code breakpoint" contrasts
nicely with a watchpoint also being typically known as a "data
breakpoint".
After this commit, the resulting hierarchy looks like:
breakpoint
code_breakpoint
ordinary_breakpoint
internal_breakpoint
momentary_breakpoint
ada_catchpoint
exception_catchpoint
tracepoint
watchpoint
catchpoint
exec_catchpoint
...
... which makes a lot more sense to me.
I've left this patch as last in the series in case people want to
bikeshed on the naming.
"code" has a nice property that it's exactly as many letters as
"base", so this patch didn't require any reindentation. :-)
Change-Id: Id8dc06683a69fad80d88e674f65e826d6a4e3f66
This tweaks the intro comments of the following classes:
internal_breakpoint
momentary_breakpoint
breakpoint
base_breakpoint
watchpoint
catchpoint
Change-Id: If6b31f51ebbb81705fbe5b8435f60ab2c88a98c8
After the previous patches, only base_breakpoint subclasses use
add_location(sal), so we can move it to base_breakpoint (a.k.a. base
class for code breakpoints).
This requires a few casts here and there, but always at spots where
you can see from context what the breakpoint's type actually is.
I inlined new_single_step_breakpoint into its only caller exactly for
this reason.
I did try to propagate more use of base_breakpoint to avoid casts, but
that turned out unwieldy for this patch.
Change-Id: I49d959322b0fdce5a88a216bb44730fc5dd7c6f8
Move common bits of catchpoint and exception_catchpoint to
breakpoint's ctor, to avoid duplicating code.
Change-Id: I3a115180f4d496426522f1d89a3875026aea3cf2
struct catchpoint's ctor currently calls init_raw_breakpoint, which is
a bit weird, as that ctor-like function takes a sal argument, but
catchpoints don't have code locations.
Instead, make struct catchpoint's ctor add the catchpoint's dummy
location using add_dummy_location.
init_raw_breakpoint uses add_location under the hood, and with a dummy
sal it would ultimately use the breakpoint's gdbarch for the
location's gdbarch, so replace the references to loc->gdbarch (which
is now NULL) in syscall_catchpoint to references to the catchpoint's
gdbarch.
struct catchpoint's ctor was the last user of init_raw_breakpoint, so
this commit eliminates the latter.
Since catchpoint locations aren't code locations, make struct
catchpoint inherit struct breakpoint instead of base_breakpoint. This
let's us delete the tracepoint::re_set override too.
Change-Id: Ib428bf71efb09fdaf399c56e4372b0f41d9c5869
Software watchpoints allocate a special dummy location using
software_watchpoint_add_no_memory_location, and then
breakpoint_address_bits checks whether the location is that special
location to decide whether the location has a meaninful address to
print.
Introduce a new bp_loc_software_watchpoint location kind, and make
breakpoint_address_bits use bl_address_is_meaningful instead, which
returns false for bp_loc_other, which is in accordance with we
document for bp_location::address:
/* (... snip ...) Valid for all types except
bp_loc_other. */
CORE_ADDR address = 0;
Rename software_watchpoint_add_no_memory_location to
add_dummy_location, and simplify it. This will be used by catchpoints
too in a following patch.
Note that neither "info breakpoints" nor "maint info breakpoints"
actually prints the addresses of watchpoints, but I think it would be
useful to do so in "maint info breakpoints". This approach let's us
implement that in the future.
Change-Id: I50e398f66ef618c31ffa662da755eaba6295aed7
Currently, init_ada_exception_catchpoint is defined in breakpoint.c, I
presume so it can call the static describe_other_breakpoints function.
I think this is a dependency inversion.
init_ada_exception_catchpoint, being code specific to Ada catchpoints,
should be in ada-lang.c, and describe_other_breakpoints, a core
function, should be exported.
And then, we can convert init_ada_exception_catchpoint to an
ada_catchpoint ctor.
Change-Id: I07695572dabc5a75d3d3740fd9b95db1529406a1
This converts init_breakpoint_sal to a base_breakpoint constructor.
It removes a use of init_raw_breakpoint.
To avoid manually adding a bunch of parameters to
new_breakpoint_from_type, and manually passing them down to the
constructors of a number of different base_breakpoint subclasses, make
new_breakpoint_from_type a variable template function.
Change-Id: I4cc24133ac4c292f547289ec782fc78e5bbe2510
This makes tracepoints inherit from base_breakpoint, since their
locations are code locations. If we do that, then we can eliminate
tracepoint::re_set and tracepoint::decode_location, as they are doing
the same as the base_breakpoint implementations.
With this, all breakpoint types created by new_breakpoint_from_type
are code breakpoints, i.e., base_breakpoint subclasses, and thus we
can make it return a base_breakpoint pointer.
Finally, init_breakpoint_sal can take a base_breakpoint pointer as
"self" pointer too. This will let us convert this function to a
base_breakpoint ctor in a following patch.
Change-Id: I3a4073ff1a4c865f525588095c18dc42b744cb54
Make add_location_to_breakpoint be a method of struct breakpoint.
A patch later in the series will move this to base_breakpoint, but for
now, it needs to be here.
Change-Id: I5bdc2ec1a7c2d66f26f51bf6f6adc8384a90b129
This introduces a catchpoint class that is used as the base class for
all catchpoints. init_catchpoint is rewritten to be a constructor
instead.
This changes the hierarchy a little -- some catchpoints now inherit
from base_breakpoint whereas previously they did not. This isn't a
problem, as long as re_set is redefined in catchpoint.
This adds some initializers to tracepoint. I think right now these
may not be needed, due to obscure rules about zero initialization.
However, this will change in the next patch, and anyway it is clearer
to be explicit.
This changes print_recreate_thread to be a method on breakpoint. This
function is only used as a helper by print_recreate methods, so I
thought this transformation made sense.
The type_wanted value, passed down to the create_sals_from_location
callback, is never used. Remove it.
Change-Id: Ic363ee13f6af593a3e875ff7fe46de130cdc190c
At this point, all implementations of breakpoints use the vtable. So,
we can now remove most function pointers from breakpoint_ops and
switch to using methods directly in the callers. Only the two "static
virtual" methods remain in breakpoint_ops.
Because the actual construction of a breakpoint is buried deep in
create_breakpoint, at present it's necessary to have a new bp_
enumerator constant any time a new subclass is needed. Static marker
tracepoints are one such case, so this patch introduces
bp_static_marker_tracepoint and updates various spots to recognize it.
This converts "ordinary" breakpoint to use vtable_breakpoint_ops.
Recall that an ordinary breakpoint is both the kind normally created
by users, and also a base class used by other classes.
