1458 Commits

Author SHA1 Message Date
bc45f5366e Remove REPARSE condition to force hardware resource checking when updating watchpoints
Currently the resource checking is done if REPARSE is true.  The hardware
watchpoint resource checking in update_watchpoint needs to be redone on
each call to function update_watchpoints as the value chain may have
changed.  The number of hardware registers needed for a watchpoint can
change if the variable being watched changes.  This situation occurs in
this test when watching variable **global_ptr_ptr.  Initially when the
watch command is issued, only two addresses need to be watched as
**global_ptr_ptr has not yet been initialized.  Once the value of
**global_ptr_ptr is initialized the locations to be tracked increase to
three addresses.  However, update_watchpoints is not called again with
REPARSE set to 1 to force the resource checking to be redone.  When the
test is run on Power 10, an internal gdb error occurs when the PowerPC
routine tries to setup the three hardware watchpoint address since the hw
only has two hardware watchpoint registers.  The error occurs because the
resource checking was not redone in update_watchpoints after
**global_ptr_ptr changed.

The following descibes the situation in detail that occurs on Power 10 with
gdb running on the binary for gdb.base/watchpoint.c.

1 break func4
2 run
3 watch *global_ptr
4 next      execute source code:   buf[0] = 3;
5 next      execute source code:   global_ptr = buf;
6 next      execute source code:   buf[0] = 7;
7 delete 2  (delete watch *global_ptr)
8 watch **global_ptr_ptr
9 next       execute source code:   buf[1] = 5;
10 next      global_ptr_ptr = &global_ptr;
11 next      buf[0] = 9;

In step 8, the the watch **global_ptr_prt command calls update_watchpoint
in breakpoint.c with REPARSE set to 1.  The function update_watchpoint
calls can_use_hardware_watchpoint to see if there are enough
resources available to add the watchpoint since REPARSE is set to 1.  At
this point, **global_ptr_ptr has not been initialized so only two addresses
are watched.  The val_chain contains the address for **global_ptr_ptr and 0
since **global_ptr_ptr has not been initialized.  The update_watchpoint
updates the breakpoint list as follows:

  breakpoint 0
   loc 0: b->address = 0x100009c0
  breakpoint 1
   loc 1: b->address = 0x7ffff7f838a0
  breakpoint 2
   loc 2: b->address = 0x7ffff7b7fc54
  breakpoint 3
   loc 3: b->address = 0x7ffff7a5788c
  breakpoint 4
   loc 4: b->address = 0x0         <-- location pointed to by global_ptr_ptr
   loc 5: b->address = 0x100200b8  <-- global_ptr_ptr watchpoint
  breakpoint 5
   loc 6: b->address = 0x7ffff7b7fc54

In step 10, the next command executes the source code
global_ptr_ptr = &global_ptr.  This changes the set of locations to be
watched for the watchpoint **global_ptr_prt.  The list of addresses for the
breakpoint consist of the address for global_ptr_prt, global_ptr and buf.
The breakpoint list gets updated by update_watchpoint as follows:

  breakpoint 0
   loc 0: b->address = 0x100009c0
  breakpoint 1
   loc 1: b->address = 0x7ffff7f838a0
  breakpoint 2
   loc 2: b->address = 0x7ffff7b7fc54
  breakpoint 3
   loc 3: b->address = 0x7ffff7a5788c
  breakpoint 4
   loc 4: b->address = 0x10020050           buf
   loc 5: b->address = 0x100200b0           watch *global_ptr
   loc 6: b->address = 0x100200b8           watch **global_ptr_ptr
  breakpoint 5
   loc 7: b->address = 0x7ffff7b7fc54
  breakpoint 6

However, the hardware resource checking was not redone because
update_breakpoint was called with REPARSE equal to  0.

Step 11, execute the third next command.  The function
ppc_linux_nat_target::low_prepare_to_resume() attempts a ptrace
call to setup each of the three address for breakpoint 4.  The slot
value returned for the third ptrace call is -1 indicating an error
because there are only two hardware watchpoint registers available on
Power 10.

This patch removes just the statement "if (reparse)" in function
update_watchpoint to force the resources to be rechecked on every call to
the function.  This ensures that any changes to the val_chain resulting
in needing more resources then available will be caught.

The patch has been tested on Power 8, Power 10 and X86-64.  Note the patch
has no effect on Power 9 since hardware watchpoint support is disabled on
that processor.
2022-10-31 14:44:17 -04:00
47e2c30aac [gdb] Rewrite RETHROW_ON_TARGET_CLOSE_ERROR into function
Recent commit b2829fcf9b5 ("[gdb] Fix rethrow exception slicing in
insert_bp_location") introduced macro RETHROW_ON_TARGET_CLOSE_ERROR.

I wrote this as a macro in order to have the rethrowing throw be part of the
same function as the catch, but as it turns out that's not necessary.

Rewrite into a function.

Tested on x86_64-linux.
2022-10-25 11:32:41 +02:00
b2829fcf9b [gdb] Fix rethrow exception slicing in insert_bp_location
The preferred way of rethrowing an exception is by using throw without
expression, because it avoids object slicing of the exception [1].

Fix this in insert_bp_location.

Tested on x86_64-linux.

[1] https://en.cppreference.com/w/cpp/language/throw

Approved-By: Andrew Burgess <aburgess@redhat.com>
2022-10-24 14:20:49 +02:00
d8de7963a9 gdb: some int to bool conversion in breakpoint.c
Some int to bool conversion in breakpoint.c.  I've only updated the
function signatures of static functions, but I've updated some
function local variables throughout the file.

There should be no user visible changes after this commit.

Approved-By: Simon Marchi <simon.marchi@efficios.com>
2022-10-20 16:41:51 +01:00
aaa141a0a9 gdb: make use of scoped_restore in unduplicated_should_be_inserted
I noticed that we could make use of a scoped_restore in the function
unduplicated_should_be_inserted.  I've also converted the function
return type from int to bool.

This change shouldn't make any difference, as I don't think anything
within should_be_inserted could throw an exception, but the change
doesn't hurt, and will help keep us safe if anything ever changes in
the future.

Approved-By: Simon Marchi <simon.marchi@efficios.com>
2022-10-20 16:41:51 +01:00
705b6305ed gdb: used scoped_restore_frame in update_watchpoint
I was doing some int to bool cleanup in update_watchpoint, and I
noticed a manual version of scoped_restore_selected_frame.  As always
when these things are done manually, there is the chance that, in an
error case, we might leave the wrong frame selected.

This commit updates things to use scoped_restore_selected_frame, and
also converts a local variable from int to bool.

The only user visible change after this commit is in the case where
update_watchpoint throws an error - we should now correctly restore
the previously selected frame.  Otherwise, this commit should be
invisible to the user.

Approved-By: Simon Marchi <simon.marchi@efficios.com>
2022-10-20 16:41:51 +01:00
b2ff9ed305 gdb: make some bp_location arguments const in breakpoint.c
I spotted a few places where I could make some 'bp_location *'
arguments constant in breakpoint.c.

There should be no user visible changes after this commit.

Approved-By: Simon Marchi <simon.marchi@efficios.com>
2022-10-20 16:41:51 +01:00
508ccf9b3e [gdb] Fix assert in handle_jit_event
With the cc-with-tweaks.sh patch submitted here (
https://sourceware.org/pipermail/gdb-patches/2022-October/192586.html ) we run
with:
...
$ export STRIP_ARGS_STRIP_DEBUG=--strip-all
$ make check RUNTESTFLAGS="gdb.base/jit-reader.exp \
    --target_board cc-with-gnu-debuglink"
...
into the following assert:
...
(gdb) run ^M
Starting program: jit-reader ^M
gdb/jit.c:1247: internal-error: jit_event_handler: \
  Assertion `jiter->jiter_data != nullptr' failed.^M
...

Fix this by handling the
jit_bp_sym.objfile->separate_debug_objfile_backlink != nullptr case in
handle_jit_event.

Tested on x86_64-linux.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29277
2022-10-19 17:41:47 +02:00
f34652de0b internal_error: remove need to pass __FILE__/__LINE__
Currently, every internal_error call must be passed __FILE__/__LINE__
explicitly, like:

  internal_error (__FILE__, __LINE__, "foo %d", var);

The need to pass in explicit __FILE__/__LINE__ is there probably
because the function predates widespread and portable variadic macros
availability.  We can use variadic macros nowadays, and in fact, we
already use them in several places, including the related
gdb_assert_not_reached.

So this patch renames the internal_error function to something else,
and then reimplements internal_error as a variadic macro that expands
__FILE__/__LINE__ itself.

The result is that we now should call internal_error like so:

  internal_error ("foo %d", var);

Likewise for internal_warning.

The patch adjusts all calls sites.  99% of the adjustments were done
with a perl/sed script.

The non-mechanical changes are in gdbsupport/errors.h,
gdbsupport/gdb_assert.h, and gdb/gdbarch.py.

Approved-By: Simon Marchi <simon.marchi@efficios.com>
Change-Id: Ia6f372c11550ca876829e8fd85048f4502bdcf06
2022-10-19 15:32:36 +01:00
98ed24fb35 Use checked_static_cast in more places
I looked through all the uses of static_cast<... *> in gdb and
converted many of them to checked_static_cast.

I couldn't test a few of these changes.
2022-10-16 10:50:47 -06:00
65558ca5df Use scoped_value_mark in more places
I looked at all the spots using value_mark, and converted all the
straightforward ones to use scoped_value_mark instead.

Regression tested on x86-64 Fedora 34.
2022-10-14 11:21:02 -06:00
bd2b40ac12 Change GDB to use frame_info_ptr
This changes GDB to use frame_info_ptr instead of frame_info *
The substitution was done with multiple sequential `sed` commands:

sed 's/^struct frame_info;/class frame_info_ptr;/'
sed 's/struct frame_info \*/frame_info_ptr /g' - which left some
    issues in a few files, that were manually fixed.
sed 's/\<frame_info \*/frame_info_ptr /g'
sed 's/frame_info_ptr $/frame_info_ptr/g' - used to remove whitespace
    problems.

The changed files were then manually checked and some 'sed' changes
undone, some constructors and some gets were added, according to what
made sense, and what Tromey originally did

Co-Authored-By: Bruno Larsen <blarsen@redhat.com>
Approved-by: Tom Tomey <tom@tromey.com>
2022-10-10 11:57:10 +02:00
a0cbd6505e Remove frame_id_eq
This replaces frame_id_eq with operator== and operator!=.  I wrote
this for a version of this series that I later abandoned; but since it
simplifies the code, I left this patch in.

Approved-by: Tom Tomey <tom@tromey.com>
2022-10-10 11:57:10 +02:00
80e0c6dc91 gdb: add missing nullptr checks in bpstat_check_breakpoint_conditions
Add a couple of missing nullptr checks in the function
bpstat_check_breakpoint_conditions.

No user visible change after this commit.
2022-10-06 10:01:15 +01:00
d8a77e4c80 gdb: more infrun debug from breakpoint.c
This commit adds additional infrun debug from the breakpoint.c file.
The new debug output all relates to breakpoint condition evaluation.

There is already some infrun debug emitted from the breakpoint.c file,
so hopefully, adding more will not be contentious.  I think the
functions being instrumented make sense as part of the infrun process,
the inferior stops, evaluates the condition, and then either stops or
continues.  This new debug gives more insight into that process.

I had to make the bp_location* argument to find_loc_num_by_location
const, and add a declaration for find_loc_num_by_location.

There should be no user visible changes unless they turn on debug
output.
2022-10-06 10:01:15 +01:00
8f5bc64185 Remove decode_location_spec_default
This removes decode_location_spec_default, inlining it into its sole
caller.

Regression tested on x86-64 Fedora 34.
2022-10-04 16:17:08 -06:00
df86565b31 gdb: remove TYPE_LENGTH
Remove the macro, replace all uses with calls to type::length.

Change-Id: Ib9bdc954576860b21190886534c99103d6a47afb
2022-09-21 11:05:21 -04:00
992aeed80b Use ui_out_redirect_pop in more places
This changes ui_out_redirect_pop to also perform the redirection, and
then updates several sites to use this, rather than explicit
redirects.
2022-08-31 11:03:39 -06:00
f79688953f gdb: update ranged_breakpoint::print_one_detail in comments
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.
2022-08-30 21:06:51 +08:00
403c71fdac gdb: change bpstat_print's kind parameter to target_waitkind
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
2022-08-26 10:32:08 -04:00
aef4b7a5cc Move decode_location_spec to code_breakpoint
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.
2022-08-13 18:47:55 -06:00
2c9a6d728e Change location_spec_to_sals to a method
location_spec_to_sals is only ever called for code breakpoints, so
make it a protected method there.
2022-08-13 18:47:55 -06:00
b3d5660a7a Change breakpoint_re_set_default to a method
breakpoint_re_set_default is only ever called from breakpoint re_set
methods, so make it a protected method on code_breakpoint.
2022-08-13 18:47:55 -06:00
9db0d8536d gdb/mi: fix breakpoint script field output
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
2022-08-10 15:38:19 -04:00
08b8a139c9 Rewrite registry.h
This rewrites registry.h, removing all the macros and replacing it
with relatively ordinary template classes.  The result is less code
than the previous setup.  It replaces large macros with a relatively
straightforward C++ class, and now manages its own cleanup.

The existing type-safe "key" class is replaced with the equivalent
template class.  This approach ended up requiring relatively few
changes to the users of the registry code in gdb -- code using the key
system just required a small change to the key's declaration.

All existing users of the old C-like API are now converted to use the
type-safe API.  This mostly involved changing explicit deletion
functions to be an operator() in a deleter class.

The old "save/free" two-phase process is removed, and replaced with a
single "free" phase.  No existing code used both phases.

The old "free" callbacks took a parameter for the enclosing container
object.  However, this wasn't truly needed and is removed here as
well.
2022-07-28 14:16:50 -06:00
e5213e2c85 gdb/python: Add BreakpointLocation type
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
2022-07-28 11:20:46 -06:00
602707187f gdb: select suitable thread for gdbarch_adjust_breakpoint_address
The three targets that implement gdbarch_adjust_breakpoint_address are
arm, frv, and mips.  In each of these targets the adjust breakpoint
address function does some combination of reading the symbol table, or
reading memory at the location the breakpoint could be placed.

The problem is that performing these actions requires that the current
inferior and program space be the one in which the breakpoint will be
placed, and this is not currently always the case.

Consider a GDB session with multiple inferiors.  One inferior might be
a native target while another could be a remote target of a completely
different architecture.  Alternatively, if we consider ARM and
AArch64, one native inferior might be AArch64, while a second native
inferior could be ARM.

In these cases it is possible, and valid, for a user to have one
inferior selected, and place a breakpoint in the other inferior by
placing a breakpoint on a particular symbol.

If this happens, then currently, when
gdbarch_adjust_breakpoint_address is called, the wrong inferior (and
program space) will be selected, and memory reads, and symbol look
ups, will not return the expected results, this could lead to
breakpoints being placed in the wrong location.

There are currently two places where gdbarch_adjust_breakpoint_address
is called:

  1. In infrun.c, in the function handle_step_into_function.  In this
  case, I believe that the correct inferior and program space will
  already be selected as this is called as part of the stop event
  handling, so I don't think we need to worry about this case, and

  2. In breakpoint.c, in the function adjust_breakpoint_address, which
  is itself called from code_breakpoint::add_location and
  watch_command_1.

  The watch_command_1 case I don't think we need to worry about, this
  is for when a local watch expression is created, which can only be
  in the currently selected inferior, so this case should be fine.

  The code_breakpoint::add_location case is the one that needs fixing,
  this is what allows a breakpoint to be created between inferiors.

To fix the code_breakpoint::add_location case, I propose that we pass
the "correct" program_space (i.e. the program space in which the
breakpoint will be created) to the adjust_breakpoint_address function.
Then in adjust_breakpoint_address we can make use of
switch_to_program_space_and_thread to switch program_space and
inferior before calling gdbarch_adjust_breakpoint_address.

I discovered this issue while working on a later patch in this
series.  This later patch will detect when we cast the result of
gdbarch_tdep to the wrong type.

With this later patch in place I ran gdb.multi/multi-arch.exp on an
AArch64 target.  In this situation, two inferiors are created, an
AArch64 inferior, and an ARM inferior.  The test selected the AArch64
inferior and tries to create a breakpoint in the ARM inferior.

As a result of this we end up in arm_adjust_breakpoint_address, which
calls arm_pc_is_thumb.  Before this commit the AArch64 inferior would
be current.  As a result, all of the checks in arm_pc_is_thumb would
fail (they rely on reading symbols from the current program space),
and so, at the end of arm_pc_is_thumb we would call
arm_frame_is_thumb.  However, remember, at this point the current
inferior is the AArch64 inferior, so the current frame is an AArch64
frame.

In arm_frame_is_thumb we call arm_psr_thumb_bit, which calls
gdbarch_tdep and casts the result to arm_gdbarch_tdep.  This is wrong,
the tdep field is of type aarch64_gdbarch_tdep.  After this we have
undefined behaviour.

With this patch in place, we will have switched to a thread in the ARM
program space before calling arm_adjust_breakpoint_address.  As a
result, we now succeed in looking up the required symbols in
arm_pc_is_thumb, and so we never call arm_frame_is_thumb.

However, in the worst case scenario, if we did end up calling
arm_frame_is_thumb, as the current inferior should now be the ARM
inferior, the current frame should be an ARM frame, so we still should
not hit undefined behaviour.

I have added an assert to arm_frame_is_thumb.
2022-07-21 15:19:41 +01:00
0f443d1b70 Fix "until LINE" in main, when "until" runs into longjmp
With a test like this:

1       #include <dlfcn.h>
2       int
3       main ()
4       {
5          dlsym (RTLD_DEFAULT, "FOO");
6          return 0;
7       }

and then "start" followed by "until 6", GDB currently incorrectly
stops inside the runtime loader, instead of line 6.  Vis:

  ...
  Temporary breakpoint 1, main () at until.c:5
  4       {
  (gdb) until 6
  0x00007ffff7f0a90d in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdb00, operate=<optimized out>, args=0x7ffff7f0a90d <__GI__dl_catch_exception+109>) at dl-error-skeleton.c:206
  206     dl-error-skeleton.c: No such file or directory.
  (gdb)

The problem is related to longjmp handling -- dlsym internally
longjmps on error.  The testcase can be reduced to this:

1       #include <setjmp.h>
2       void func () {
3         jmp_buf buf;
4         if (setjmp (buf) == 0)
5           longjmp (buf, 1);
6       }
7
8       int main () {
9         func ();
10        return 0; /* until to here */
11      }

and then with "start" followed by "until 10", GDB currently
incorrectly stops at line 4 (returning from setjmp), instead of line
10.

The problem is that the BPSTAT_WHAT_CLEAR_LONGJMP_RESUME code in
infrun.c fails to find the initiating frame, and so infrun thinks that
the longjmp jumped somewhere outer to "until"'s originating frame.

Here:

    case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
      {
	struct frame_info *init_frame;

	/* There are several cases to consider.

	   1. The initiating frame no longer exists.  In this case we
	   must stop, because the exception or longjmp has gone too
	   far.

        ...

	init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);

	if (init_frame)   // this is NULL!
	  {
	     ...
	  }

	/* For Cases 1 and 2, remove the step-resume breakpoint, if it
	   exists.  */
	delete_step_resume_breakpoint (ecs->event_thread);

	end_stepping_range (ecs);   // case 1., so we stop.
      }

The initiating frame is set by until_break_command ->
set_longjmp_breakpoint.  The initiating frame is supposed to be the
frame that is selected when the command was issued, but
until_break_command instead passes the frame id of the _caller_ frame
by mistake.  When the "until LINE" command is issued from main, the
caller frame is the caller of main.  When later infrun tries to find
that frame by id, it fails to find it, because frame_find_by_id
doesn't unwind past main.

The bug is that we passed the caller frame's id to
set_longjmp_breakpoint.  We should have passed the selected frame's id
instead.

Change-Id: Iaae1af7cdddf296b7c5af82c3b5b7d9b66755b1c
2022-07-13 14:20:49 +01:00
709438c75a Convert location_spec_to_string to a method
This converts location_spec_to_string to a method of location_spec,
simplifying the code using it, as it no longer has to use
std::unique_ptr::get().

Change-Id: I621bdad8ea084470a2724163f614578caf8f2dd5
2022-06-17 09:58:49 +01:00
7464aeaab4 Convert location_spec_type to a method
This converts location_spec_type to location_spec::type().

Change-Id: Iff4cbfafb1cf3d22adfa142ff939b4a148e52273
2022-06-17 09:58:49 +01:00
238dc9af03 Convert location_spec_empty_p to a method
This converts location_spec_empty_p to a method of location_spec,
simplifying users, as they no longer have to use
std::unique_ptr::get().

Change-Id: I83381a729896f12e1c5a1b4d6d4c2eb1eb6582ff
2022-06-17 09:58:49 +01:00
5c1ddcb69a Eliminate copy_location_spec
copy_location_spec is just a wrapper around location_spec::clone(), so
remove it and call clone() directly.  This simplifies users, as they
no longer have to use std::unique_ptr::get().

Change-Id: I8ce8658589460b98888283b306b315a5b8f73976
2022-06-17 09:58:49 +01:00
40d97ee21f Eliminate the two-level data structures behind location_specs
Currently, there's the location_spec hierarchy, and then some
location_spec subclasses have their own struct type holding all their
data fields.

I.e., there is this:

 location_spec
   explicit_location_spec
   linespec_location_spec
   address_location_spec
   probe_location_spec

and then these separate types:

  explicit_location
  linespec_location

where:

  explicit_location_spec
     has-a explicit_location
  linespec_location_spec
     has-a linespec_location

This patch eliminates explicit_location and linespec_location,
inlining their members in the corresponding location_spec type.

The location_spec subclasses were the ones currently defined in
location.c, so they are moved to the header.  Since the definitions of
the classes are now visible, we no longer need location_spec_deleter.

Some constructors that are used for cloning location_specs, like:

  explicit explicit_location_spec (const struct explicit_location *loc)

... were converted to proper copy ctors.

In the process, initialize_explicit_location is eliminated, and some
functions that returned the "data type behind a locspec", like
get_linespec_location are converted to downcast functions, like
as_linespec_location_spec.

Change-Id: Ia31ccef9382b25a52b00fa878c8df9b8cf2a6c5a
2022-06-17 09:55:39 +01:00
264f98902f event_location -> location_spec
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
2022-06-17 09:41:24 +01:00
fbcda57701 Show enabled locations with disabled breakpoint parent as "y-"
Currently, breakpoint locations that are enabled while their parent
breakpoint is disabled are displayed with "y" in the Enb colum of
"info breakpoints":

 (gdb) info breakpoints
 Num     Type           Disp Enb Address            What
 1       breakpoint     keep n   <MULTIPLE>
 1.1                         y   0x00000000000011b6 in ...
 1.2                         y   0x00000000000011c2 in ...
 1.3                         n   0x00000000000011ce in ...

Such locations won't trigger a break, so to avoid confusion, show "y-"
instead.  For example:

 (gdb) info breakpoints
 Num     Type           Disp Enb Address            What
 1       breakpoint     keep n   <MULTIPLE>
 1.1                         y-  0x00000000000011b6 in ...
 1.2                         y-  0x00000000000011c2 in ...
 1.3                         n   0x00000000000011ce in ...

The "-" sign is inspired on how the TUI represents breakpoints on the
left side of the source window, with "b-" for a disabled breakpoint.

Change-Id: I9952313743c51bf21b4b380c72360ef7d4396a09
2022-05-25 19:51:46 +01:00
74421c0bc8 Rename base_breakpoint -> code_breakpoint
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
2022-05-20 20:41:02 +01:00
7ab979957c Make sure momentary breakpoints are always thread-specific
This adds a new ctor to momentary_breakpoints with a few parameters
that are always necessary for momentary breakpoints.

In particular, I noticed that set_std_terminate_breakpoint doesn't
make the breakpoint be thread specific, which looks like a bug to me.

The point of that breakpoint is to intercept std::terminate calls that
happen as result of the called thread throwing an exception that won't
be caught by the dummy frame.  If some other thread calls
std::terminate, IMO, it's no different from some other thread calling
exit/_exit, for example.

Change-Id: Ifc5ff4a6d6e58b8c4854d00b86725382d38a1a02
2022-05-20 20:41:02 +01:00
f970305146 Momentary breakpoints should have no breakpoint number
Momentary breakpoints have no breakpoint number, their breakpoint
number should be always 0, to avoid constantly incrementing (or
decrementing) the internal breakpoint count.

Indeed, set_momentary_breakpoint installs the created breakpoint
without a number.

However, momentary_breakpoint_from_master incorrectly gives an
internal breakpoint number to the new breakpoint.  This commit fixes
that.

Change-Id: Iedcae5432cdf232db9e9a6e1a646d358abd34f95
2022-05-20 20:41:02 +01:00
9a71ed14cb Add/tweak intro comments of struct breakpoint and several subclasses
This tweaks the intro comments of the following classes:

 internal_breakpoint
 momentary_breakpoint
 breakpoint
 base_breakpoint
 watchpoint
 catchpoint

Change-Id: If6b31f51ebbb81705fbe5b8435f60ab2c88a98c8
2022-05-20 20:41:01 +01:00
960bc2bd14 Move add_location(sal) to base_breakpoint
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
2022-05-20 20:41:01 +01:00
92bb0228c8 Move common bits of catchpoint/exception_catchpoint to breakpoint's ctor
Move common bits of catchpoint and exception_catchpoint to
breakpoint's ctor, to avoid duplicating code.

Change-Id: I3a115180f4d496426522f1d89a3875026aea3cf2
2022-05-20 20:41:01 +01:00
acd0955bc1 Make catchpoint inherit breakpoint, eliminate init_raw_breakpoint
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
2022-05-20 20:41:01 +01:00
6e14e4412b Make breakpoint_address_bits look at the location kind
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
2022-05-20 20:41:01 +01:00
7a3e3265ed Refactor momentary breakpoints, eliminate set_raw_breakpoint{,_without_location}
This commit makes set_momentary_breakpoint allocate the breakpoint
type without relying on set_raw_breakpoint, and similarly,
momentary_breakpoint_from_master not rely on
set_raw_breakpoint_without_location.  This will let us convert
init_raw_breakpoint to a ctor in a following patch.

The comment about set_raw_breakpoint being used in gdbtk sources is
stale.  gdbtk no longer uses it.

Change-Id: Ibbf77731e4b22e18ccebc1b5799bbec0aff28c8a
2022-05-20 20:41:01 +01:00
752a2291b1 Refactor set_internal_breakpoint / internal_breakpoint ctor
This moves initialization of internal_breakpoint's breakpoint fields
to internal_breakpoint's ctor, and stops using
new_breakpoint_from_type for internal_breakpoint breakpoints.

Change-Id: I898ed0565f47cb00e4429f1c6446e6f9a385a78d
2022-05-20 20:41:01 +01:00
bd21b6c9cf Convert init_ada_exception_catchpoint to a ctor
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
2022-05-20 20:41:01 +01:00
3b003a6126 init_breakpoint_sal -> base_breakpoint::base_breakpoint
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
2022-05-20 20:41:00 +01:00
d837fd813d Remove "internal" parameter from a couple functions
None of init_breakpoint_sal, create_breakpoint_sal, and
strace_marker_create_breakpoints_sal make use of their "internal"
parameter, so remove it.

Change-Id: I943f3bb44717ade7a7b7547edf8f3ff3c37da435
2022-05-20 20:41:00 +01:00
ef4848c75f More breakpoint_ops parameter elimination
Remove breakpoint_ops parameters from a few functions that don't need
it.

Change-Id: Ifcf5e1cc688184acbf5e19b8ea60138ebe63cf28
2022-05-20 20:41:00 +01:00
ff733ec228 Make a few functions work with base_breakpoint instead of breakpoint
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
2022-05-20 20:41:00 +01:00