Commit graph

52139 commits

Author SHA1 Message Date
Tom Tromey
309d28d1e4 Optimize lookup_minimal_symbol_text
lookup_minimal_symbol_text always loops over all objfiles, even when
an objfile is passed in as an argument.  This patch changes the
function to loop over the minimal number of objfiles in the latter
situation.
2024-01-08 18:40:22 -07:00
Tom Tromey
0a008773c5 Lazy language setting
When gdb starts up with a symbol file, it uses the program's "main" to
decide the "static context" and the initial language.  With background
DWARF reading, this means that gdb has to wait for a significant
amount of DWARF to be read synchronously.

This patch introduces lazy language setting.  The idea here is that in
many cases, the prompt can show up early, making gdb feel more
responsive.
2024-01-08 18:40:22 -07:00
Tom Tromey
c83a280218 Change current_language to be a macro
This changes the 'current_language' global to be a macro that wraps a
function call.  This change will let a subsequent patch introduce lazy
language setting.
2024-01-08 18:40:22 -07:00
Tom Tromey
245703b3ce Remove two quick_symbol_functions methods
quick_symbol_functions::read_partial_symbols is no longer implemented,
so both it and quick_symbol_functions::can_lazily_read_symbols can be
removed.  This allows for other functions to be removed as well.

Note that SYMFILE_NO_READ is now pretty much dead.  I haven't removed
it here -- but could if that's desirable.  I tend to think that this
functionality would be better implemented in the core; but whenever I
dive into the non-DWARF readers it is pretty depressing.
2024-01-08 18:40:21 -07:00
Tom Tromey
aecbdf5f34 Simplify the public DWARF API
dwarf2_has_info and dwarf2_initialize_objfile are only separate
because the DWARF reader implemented lazy psymtab reading.  However,
now that this is gone, we can simplify the public DWARF API again.
2024-01-08 18:40:21 -07:00
Tom Tromey
33c6eaaefc Do more DWARF reading in the background
This patch rearranges the DWARF reader so that more work is done in
the background.  This is PR symtab/29942.

The idea here is that there is only a small amount of work that must
be done on the main thread when scanning DWARF -- before the main
scan, the only part is mapping the section data.

Currently, the DWARF reader uses the quick_symbol_functions "lazy"
functionality to defer even starting to read.  This patch instead
changes the reader to start reading immediately, but doing more in
worker tasks.

Before this patch, "file" on my machine:

    (gdb) file /tmp/gdb
    2023-10-23 12:29:56.885 - command started
    Reading symbols from /tmp/gdb...
    2023-10-23 12:29:58.047 - command finished
    Command execution time: 5.867228 (cpu), 1.162444 (wall)

After the patch, more work is done in the background and so this takes
a bit less time:

    (gdb) file /tmp/gdb
    2023-10-23 13:25:51.391 - command started
    Reading symbols from /tmp/gdb...
    2023-10-23 13:25:51.712 - command finished
    Command execution time: 1.894500 (cpu), 0.320306 (wall)

I think this could be further sped up by using the shared library load
map to avoid objfile loops like the one in expand_symtab_containing_pc
-- it seems like the correct objfile could be chosen more directly.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29942
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30174
2024-01-08 18:40:21 -07:00
Tom Tromey
f7840e9e3e Change how cooked index waits for threads
This changes the cooked index code to wait for threads in its
public-facing API.  That is, the waits are done in cooked_index now,
and never in the cooked_index_shard.  Centralizing this decision makes
it easier to wait for other events here as well.
2024-01-08 18:40:21 -07:00
Tom Tromey
9b595a2641 Add "maint set dwarf synchronous"
For testing, it's sometimes convenient to be able to request that
DWARF reading be done synchronously.  This patch adds a new "maint"
setting for this purpose.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>
2024-01-08 18:40:21 -07:00
Tom Tromey
a274da12ea Move cooked_index_storage to cooked-index.h
This moves cooked_index_storage to cooked-index.h.  This is needed by
a subsequent patch.
2024-01-08 18:40:21 -07:00
Tom Tromey
4ea870efec Add quick_symbol_functions::compute_main_name
This adds a new compute_main_name method to quick_symbol_functions.
Currently there are no implementations of this, but a subsequent patch
will add one.
2024-01-08 18:40:21 -07:00
Tom Tromey
8e279fda0f Add deferred_warnings parameter to read_addrmap_from_aranges
When DWARF reading is done in the background,
read_addrmap_from_aranges will be called from a worker thread.
Because warnings can't be emitted from these threads, this patch adds
a new deferred_warnings parameter to the function, letting the caller
control exactly how the warnings are emitted.
2024-01-08 18:40:21 -07:00
Tom Tromey
54b815ddb4 Refactor complaint thread-safety approach
This patch changes the way complaint works in a background thread.
The new approach requires installing a complaint interceptor in each
worker, and then the resulting complaints are treated as one of the
results of the computation.  This change is needed for a subsequent
patch, where installing a complaint interceptor around a parallel-for
is no longer a viable approach.
2024-01-08 18:40:21 -07:00
Tom Tromey
da0e2ac4f7 Add thread-safety to gdb's BFD wrappers
This changes gdb to ensure that gdb's BFD cache is guarded by a lock.
This avoids any races when multiple threads might open a BFD (and thus
use the BFD cache) at the same time.

Currently, this change is not needed because the the main thread waits
for some DWARF scanning to be completed before returning.  The only
locking that's required is when opening DWO files, and there's a local
lock to this end in dwarf2/read.c.

However, in the coming patches, the DWARF reader will begin its work
earlier, in the background.  This means there is the potential for the
DWARF reader and other code on the main thread to both attempt to open
BFDs at the same time.
2024-01-08 18:40:21 -07:00
Tom Tromey
a2eb3f887c Add a couple of bfd_cache_close calls
This adds a couple of calls to bfd_cache_close at points where a BFD
isn't actively needed by gdb.  Normally at these points, all the
needed section data is already mapped, so we can simply close the file
descriptor.  This is harmless at worst, because if this is needed
after all, the BFD file descriptor cache will reopen it.
2024-01-08 18:40:21 -07:00
Tom Tromey
a37fbcfec5 Pre-read DWZ section data
This changes the DWZ code to pre-read the section data and somewhat
simplify the DWZ API.  This makes it easier to add the bfd_cache_close
call to the new dwarf2_read_dwz_file function -- after this is done,
there shouldn't be a reason to keep the BFD's file descriptor open.
2024-01-08 18:40:21 -07:00
Tom Tromey
3c2f688e70 Don't use objfile::intern in DWO code
The DWO code in the DWARF reader currently uses objfile::intern.  This
accesses a shared data structure and so would be racy when used from
multiple threads.  I don't believe this can happen right now, but
background reading could provoke this, and in any case it's better to
avoid this, just to be sure.

This patch changes this code to just use a std::string.  A new type is
introduced to do hash table lookups, to avoid unnecessary copies.
2024-01-08 18:40:21 -07:00
Joseph Myers
30a9c613df MAINTAINERS: Update my email address 2024-01-08 18:55:03 +00:00
Tom de Vries
6ccc6caf49 [gdb/testsuite] Add missing -no-prompt-anchor in gdb.base/vfork-follow-parent.exp
When running test-case gdb.base/vfork-follow-parent.exp it passes fine, but
when running it with "taskset -c 0" I run into:
...
(gdb) inferior 1^M
[Switching to inferior 1 [process 26606] (vfork-follow-parent-exit)]^M
[Switching to thread 1.1 (process 26606)]^M
(gdb) Reading symbols from vfork-follow-parent-exit...^M
FAIL: $exp: exec_file=vfork-follow-parent-exit: target-non-stop=on: \
  non-stop=off: resolution_method=schedule-multiple: inferior 1 (timeout)
...

Fix this by using -no-prompt-anchor.

Tested on x86_64-linux.

PR testsuite/31166
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31166
2024-01-08 13:01:50 +01:00
Tom de Vries
09f5e4ed86 [gdb/testsuite] Make gdb.base/solib-search.exp more robust
On aarch64-linux, with gcc 13.2.1, I run into:
...
 (gdb) backtrace^M
 #0  break_here () at solib-search.c:30^M
 #1  0x0000fffff7f20194 in lib2_func4 () at solib-search-lib2.c:50^M
 #2  0x0000fffff7f70194 in lib1_func3 () at solib-search-lib1.c:50^M
 #3  0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M
 #4  0x0000fffff7f70174 in lib1_func1 () at solib-search-lib1.c:30^M
 #5  0x00000000004101b4 in main () at solib-search.c:23^M
 (gdb) PASS: gdb.base/solib-search.exp: \
   backtrace (with wrong libs) (data collection)
 FAIL: gdb.base/solib-search.exp: backtrace (with wrong libs)
...

The FAIL is generated by this code in the test-case:
...
    if { $expect_fail } {
	# If the backtrace output is correct the test isn't sufficiently
	# testing what it should.
	if { $count == $total_expected } {
	    set fail 1
	}
...

The test-case:
- builds two versions of two shared libs, a "right" and "wrong" version, the
  difference being an additional dummy function (called spacer function),
- uses the "right" version to generate a core file,
- uses the "wrong" version to interpret the core file, and
- generates a backtrace.

The intent is that the backtrace is incorrect due to using the "wrong"
version, but actually it's correct.  This is because the spacer functions
aren't large enough.

Fix this by increasing the size of the spacer functions by adding a dummy
loop, after which we have, as expected, an incorrect backtrace:
...
 (gdb) backtrace^M
 #0  break_here () at solib-search.c:30^M
 #1  0x0000fffff7f201c0 in ?? ()^M
 #2  0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M
 #3  0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M
 #4  0x0000fffff7f70174 in lib1_func1 () at solib-search-lib1.c:30^M
 #5  0x00000000004101b4 in main () at solib-search.c:23^M
 (gdb) PASS: gdb.base/solib-search.exp: \
   backtrace (with wrong libs) (data collection)
 PASS: gdb.base/solib-search.exp: backtrace (with wrong libs)
...

Tested on aarch64-linux.
2024-01-08 10:37:44 +01:00
Tom de Vries
2bcfdb758b [gdb/testsuite] Handle PAC marker
On aarch64-linux, I run into:
...
FAIL: gdb.base/annota1.exp: backtrace from shlibrary (timeout)
...
due to the PAC marker showing up:
...
^Z^Zframe-address^M
0x000000000041025c [PAC]^M
^Z^Zframe-address-end^M
...

In the docs the marker is documented as follows:
...
When GDB is debugging the AArch64 architecture, and the program is using the
v8.3-A feature Pointer Authentication (PAC), then whenever the link register
$lr is pointing to an PAC function its value will be masked.  When GDB prints
a backtrace, any addresses that required unmasking will be postfixed with the
marker [PAC].  When using the MI, this is printed as part of the addr_flags
field.
...

Update the test-case to allow the PAC marker.

Likewise in a few other test-cases.

While we're at it, rewrite the affected pattern pat_begin in annota1.exp into
a more readable form.  Likewise for the corresponding pat_end.

Tested on aarch64-linux.

Approved-By: Luis Machado <luis.machado@arm.com>

PR testsuite/31202
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31202
2024-01-04 13:42:45 +01:00
Andrew Burgess
b7a5722ebd gdb: improve error reporting from expression parser
This commits changes how errors are reported from the expression
parser.  Previously, parser errors were reported like this:

  (gdb) p a1 +}= 432
  A syntax error in expression, near `}= 432'.
  (gdb) p a1 +
  A syntax error in expression, near `'.

The first case is fine, a user can figure out what's going wrong, but
the second case is a little confusing; as the error occurred at the
end of the expression GDB just reports the empty string to the user.

After this commit the first case is unchanged, but the second case now
reports like this:

  (gdb) p a1 +
  A syntax error in expression, near the end of `a1 +'.

Which I think is clearer.  There is a possible issue if the expression
being parsed is very long, GDB will repeat the whole expression.  But
this issue already exists in the standard case; if the error occurs
early in a long expression GDB will repeat everything after the syntax
error.  So I've not worried about this case in my new code either,
which keeps things simpler.

I did consider trying to have multi-line errors here, in the style
that gcc produces, with some kind of '~~~~~^' marker on the second
line to indicate where the error occurred; but I rejected this due to
the places in GDB where we catch an error and repackage the message
within some longer string, I don't think multi-line error messages
would work well in that case.  At a minimum it would require some
significant work in order to make all our error handling multi-line
aware.

I've added a couple of extra tests in gdb.base/exprs.exp.

Approved-By: John Baldwin <jhb@FreeBSD.org>
2024-01-04 09:24:18 +00:00
Andrew Burgess
e89496f42a gdb: merge error handling from different expression parsers
Many (all?) of the expression parsers implement yyerror to handle
parser errors, and all of these functions are basically identical.

This commit adds a new parser_state::parse_error() function, which
implements the common error handling code, this function can then be
called from all the different yyerror functions.

The benefit of this is that (in a future commit) I can improve the
error output, and all the expression parsers will benefit.

This commit is pure refactoring though, and so, there should be no
user visible changes after this commit.

Approved-By: John Baldwin <jhb@FreeBSD.org>
2024-01-04 09:24:18 +00:00
Andrew Burgess
c9f1e0dfc8 gdb: don't try to style content in error calls
While working on a later commit in this series I realised that the
error() function doesn't support output styling.  Due to the way that
output from error() calls is passed around within the exception
object and often combined with other output, it's not immediately
obvious to me if we should be trying to support styling in this
context or not.

On inspection, I found one place in GDB where we apparently try to
apply styling within the error() output (in procfs.c).  I suspect this
error() call might not be tested.

Rather than try to implement styling in the error() output, right now
I'm proposing to just remove the attempt to style error() output.

This doesn't mean that someone shouldn't add error() styling in the
future, but right now, I'm not planning to do that, I just wanted to
fix this in passing.

Approved-By: John Baldwin <jhb@FreeBSD.org>
2024-01-04 09:24:18 +00:00
Carl Love
d04ead7406 Fix GDB reverse-step and reverse-next command behavior
Currently GDB when executing in reverse over multiple statements in a single
line of source code, GDB stops in the middle of the line.  Thus requiring
multiple commands to reach the previous line.  GDB should stop at the first
instruction of the line, not in the middle of the line.

The following description of the incorrect behavior was taken from an
earlier message by Pedro Alves <pedro@palves.net>:

https://sourceware.org/pipermail/gdb-patches/2023-January/196110.html

---------------------------------

The source line looks like:

   func1 ();  func2 ();

in the test case:

(gdb) list 1
1       void func1 ()
2       {
3       }
4
5       void func2 ()
6       {
7       }
8
9       int main ()
10      {
11        func1 (); func2 ();
12      }

compiled with:

 $ gcc reverse.c -o reverse -g3 -O0
 $ gcc -v
 ...
 gcc version 11.3.0 (Ubuntu 11.3.0-1ubuntu1~22.04)

Now let's debug it with target record, using current gdb git master
(f3d8ae90b2),

 $ gdb ~/reverse
 GNU gdb (GDB) 14.0.50.20230124-git
 ...
 Reading symbols from /home/pedro/reverse...
 (gdb) start
 Temporary breakpoint 1 at 0x1147: file reverse.c, line 11.
 Starting program: /home/pedro/reverse
 [Thread debugging using libthread_db enabled]
 Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

 Temporary breakpoint 1, main () at reverse.c:11
 11        func1 (); func2 ();
 (gdb) record

 (gdb) disassemble /s
 Dump of assembler code for function main:
 reverse.c:
 10      {
    0x000055555555513f <+0>:     endbr64
    0x0000555555555143 <+4>:     push   %rbp
    0x0000555555555144 <+5>:     mov    %rsp,%rbp

 11        func1 (); func2 ();
 => 0x0000555555555147 <+8>:     mov    $0x0,%eax
    0x000055555555514c <+13>:    call   0x555555555129 <func1>
    0x0000555555555151 <+18>:    mov    $0x0,%eax
    0x0000555555555156 <+23>:    call   0x555555555134 <func2>
    0x000055555555515b <+28>:    mov    $0x0,%eax

 12      }
    0x0000555555555160 <+33>:    pop    %rbp
    0x0000555555555161 <+34>:    ret
 End of assembler dump.

 (gdb) n
 12      }

So far so good, a "next" stepped over the whole of line 11 and stopped at
line 12.

Let's confirm where we are now:

 (gdb) disassemble /s
 Dump of assembler code for function main:
 reverse.c:
 10      {
    0x000055555555513f <+0>:     endbr64
    0x0000555555555143 <+4>:     push   %rbp
    0x0000555555555144 <+5>:     mov    %rsp,%rbp

 11        func1 (); func2 ();
    0x0000555555555147 <+8>:     mov    $0x0,%eax
    0x000055555555514c <+13>:    call   0x555555555129 <func1>
    0x0000555555555151 <+18>:    mov    $0x0,%eax
    0x0000555555555156 <+23>:    call   0x555555555134 <func2>
    0x000055555555515b <+28>:    mov    $0x0,%eax

 12      }
 => 0x0000555555555160 <+33>:    pop    %rbp
    0x0000555555555161 <+34>:    ret
 End of assembler dump.

Good, we're at the first instruction of line 12.

Now let's undo the "next", with "reverse-next":

 (gdb) reverse-next
 11        func1 (); func2 ();

Seemingly stopped at line 11.  Let's see exactly where:

 (gdb) disassemble /s
 Dump of assembler code for function main:
 reverse.c:
 10      {
    0x000055555555513f <+0>:     endbr64
    0x0000555555555143 <+4>:     push   %rbp
    0x0000555555555144 <+5>:     mov    %rsp,%rbp

 11        func1 (); func2 ();
    0x0000555555555147 <+8>:     mov    $0x0,%eax
    0x000055555555514c <+13>:    call   0x555555555129 <func1>
 => 0x0000555555555151 <+18>:    mov    $0x0,%eax
    0x0000555555555156 <+23>:    call   0x555555555134 <func2>
    0x000055555555515b <+28>:    mov    $0x0,%eax

 12      }
    0x0000555555555160 <+33>:    pop    %rbp
    0x0000555555555161 <+34>:    ret
 End of assembler dump.
 (gdb)

And lo, we stopped in the middle of line 11!  That is a bug, we should have
stepped back all the way to the beginning of the line.  The "reverse-next"
should have fully undone the prior "next" command.

--------------------

This patch fixes the incorrect GDB behavior by ensuring that GDB  stops at
the first instruction in the line.

The test case gdb.reverse/func-map-to-same-line.exp is added to testsuite
to verify this fix when the line table information is and is not available.
2024-01-02 17:46:12 -05:00
Carl Love
fe6356def6 PowerPC and aarch64: Fix reverse stepping failure
When running GDB's testsuite on aarch64-linux/Ubuntu 20.04 (also spotted on
the ppc backend), there are failures in gdb.reverse/solib-precsave.exp and
gdb.reverse/solib-reverse.exp.

The failure happens around the following code:

38  b[1] = shr2(17);          /* middle part two */
40  b[0] = 6;   b[1] = 9;     /* generic statement, end part two */
42  shr1 ("message 1\n");     /* shr1 one */

Normal execution:

- step from line 38 will land on line 40.
- step from line 40 will land on line 42.

Reverse execution:
- step from line 42 will land on line 40.
- step from line 40 will land on line 40.
- step from line 40 will land on line 38.

The problem here is that line 40 contains two contiguous but distinct
PC ranges in the line table, like so:

Line 40 - [0x7ec ~ 0x7f4]
Line 40 - [0x7f4 ~ 0x7fc]

The two distinct ranges are generated because GCC started outputting source
column information, which GDB doesn't take into account at the moment.

When stepping forward from line 40, we skip both of these ranges and land on
line 42. When stepping backward from line 42, we stop at the start PC of the
second (or first, going backwards) range of line 40.

Since we've reached ecs->event_thread->control.step_range_start, we stop
stepping backwards.

The above issues were fixed by introducing a new function that looks for
adjacent PC ranges for the same line, until we notice a line change. Then
we take that as the start PC of the range.  The new start PC for the range
is used for the control.step_range_start when setting up a step range.

The test case gdb.reverse/map-to-same-line.exp is added to test the fix
for the above reverse step issues.

Patch has been tested on PowerPC, X86 and AArch64 with no regressions.
2024-01-02 17:46:02 -05:00
Carl Love
29deb4221d Add gdb_compile options column-info and no-column-info
This patch adds two new options to gdb_compile to specify if the compile
should or should not generate the line table information.  The
options are supported on clang and gcc version 7 and newer.

Patch has been tested on PowerPC with both gcc and clang.
2024-01-02 17:45:55 -05:00
Guinevere Larsen
528b729be1 gdb/dwarf2: Add support for DW_LNS_set_epilogue_begin in line-table
This commit adds a mechanism for GDB to detect the linetable opcode
DW_LNS_set_epilogue_begin. This opcode is set by compilers to indicate
that a certain instruction marks the point where the frame is destroyed.

While the standard allows for multiple points marked with epilogue_begin
in the same function, for performance reasons, the function that
searches for the epilogue address will only find the last address that
sets this flag for a given block.

This commit also changes amd64_stack_frame_destroyed_p_1 to attempt to
use the epilogue begin directly, and only if an epilogue can't be found
will it attempt heuristics based on the current instruction.

Finally, this commit also changes the dwarf assembler to be able to emit
epilogue-begin instructions, to make it easier to test this patch

Approved-By: Tom Tromey <tom@tromey.com>
2024-01-02 10:21:37 +01:00
Tom Tromey
6374b0a983 Run 'black' on tui-window.py
Mark pointed out that a recent patch of mine caused the buildbot to
complain about the formatting of some Python test code.  This patch
re-runs 'black' to fix the problem.
2023-12-31 16:36:44 -07:00
Tom de Vries
276e7f5c88 [gdb/testsuite] Fix typo in gdb.base/catch-syscall.exp
On aarch64-linux with a gdb build without libexpat, I run into:
...
(gdb) PASS: gdb.base/catch-syscall.exp: determine pipe syscall: \
  catch syscall 59
continue
Continuing.

Catchpoint 5 (call to syscall 59), 0x0000fffff7e04578 in pipe () from \
  /lib64/libc.so.6
(gdb) FAIL: gdb.base/catch-syscall.exp: determine pipe syscall: continue
...

In the test-case, this pattern handles either the syscall name or number for
the pipe syscall:
...
  -re -wrap "Catchpoint $decimal \\(call to syscall (pipe|$SYS_pipe)\\).*" {
...
but the pattern for the pipe2 syscall mistakenly uses SYS_pipe instead of
SYS_pipe2:
...
  -re -wrap "Catchpoint $decimal \\(call to syscall (pipe2|$SYS_pipe)\\).*" {
...
and consequently doesn't handle the pipe2 syscall number.

Fix the typo by using SYS_pipe2 instead.

Tested on aarch64-linux.
2023-12-31 09:39:45 +01:00
Tom Tromey
1f1c84ddf7 Add keywords to TuiWindow.write
The gdb docs promise that methods with more than two or more arguments
will accept keywords.  However, I found that TuiWindow.write didn't
allow them.  This patch adds the missing support.
2023-12-30 12:21:44 -07:00
Tom de Vries
11e73fe731 [gdb/testsuite] Fix gdb.base/gdb-index-err.exp for root user
When running test-case gdb.base/gdb-index-err.exp in a container as root user,
I run into:
...
FAIL: gdb.base/gdb-index-err.exp: flag=: \
  try to write index to a non-writable directory
FAIL: gdb.base/gdb-index-err.exp: flag=-dwarf-5: \
  try to write index to a non-writable directory
...

The test-case creates a directory without write permissions:
...
$ ls -ald private
dr-xr-xr-x 2 root root 4096 Dec 29 06:26 private/
...
but apparently the root user is still able to write in it.

Fix this by making the test unsupported for the root user.

Tested on x86_64-linux.

Reviewed-By: Lancelot SIX <lancelot.six@amd.com>

PR testsuite/31197
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31197
2023-12-30 20:04:10 +01:00
Joseph Myers
b383acf248 MAINTAINERS: Update my email address
There will be another update in January.
2023-12-30 00:32:00 +00:00
Nils-Christian Kempke
3396471b4c dwarf, fortran: add support for DW_TAG_entry_point
Fortran provides additional entry points for subroutines and functions.
These entry points may use only a subset (or a different set) of the
parameters of the original subroutine.  The entry points may be described
via the DWARF tag DW_TAG_entry_point.

This commit adds support for parsing the DW_TAG_entry_point DWARF tag.
Currently, between ifx/ifort/gfortran, only ifort is actually emitting
this tag.  Both, ifx and gfortran use the DW_TAG_subprogram tag as
workaround/alternative.  Thus, this patch really only adds more ifort
support.  Even so, some of the attached tests still fail for ifort, due
to some wrong line info generated for the entry points in ifort.

After this patch it is possible to set a breakpoint in gdb with the
ifort compiled example at the entry points 'foo' and 'foobar', which was not
possible before.

As gcc and ifx do not emit the tag I also added a test to gdb.dwarf2
which uses some underlying c compiled code and adds some Fortran style DWARF
to it emitting the DW_TAG_entry_point.  Before this patch it was not
possible to actually define breakpoint at the entry point tags.

For gfortran there actually exists a bug on bugzilla, asking for the use
of DW_TAG_entry_point over DW_TAG_subprogram:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=37134

This patch was originally posted here

https://sourceware.org/legacy-ml/gdb-patches/2017-07/msg00317.html

but its review/pinging got lost after a while.  I reworked it to fit the
current GDB.

Co-authored-by: Bernhard Heckel <bernhard.heckel@intel.com>
Co-authored-by: Tim Wiederhake  <tim.wiederhake@intel.com>
Approved-by: Tom Tromey <tom@tromey.com>
2023-12-29 11:31:10 +01:00
Nils-Christian Kempke
06740cf11f gdb, dwarf: add assert to dwarf2_get_pc_bounds
In dwarf2_get_pc_bounds we were writing unchecked to *lowpc.  This
commit adds a gdb_assert to first check that lowpc != nullptr.

Approved-by: Tom Tromey <tom@tromey.com>
2023-12-29 11:28:35 +01:00
Nils-Christian Kempke
69570475c6 gdb, dwarf: move part of dwarf2_get_pc_bounds into separate function
This commit is in preparation of the next commit.  There, we will add
a second variation to retrieve the pc bounds for DIEs tagged with
DW_TAG_entry_point.  Instead of dwarf_get_pc_bounds_ranges_or_highlow_pc
we will call a separate method for entry points.  As the validity checks
at the endo f dwarf2_get_pc_bounds are the same for both variants,
we introduced the new dwarf_get_pc_bounds_ranges_or_highlow_pc method,
outsourcing part of dwarf2_get_pc_bounds.

This commit should have no functional impact on GDB.

Approved-by: Tom Tromey <tom@tromey.com>
2023-12-29 11:28:35 +01:00
Simon Marchi
32a5d479d2 gdb: make value::allocate_register_lazy store id of next non-inline frame
Some spots loop on the frame chain to find the first next non-inline
frame, and pass that as the "next frame" to
value::allocate_register_lazy / value::allocate_register.  This is
necessary if the value is used in the process of computing the id of
"this frame".  If the frame next to "this frame" is inlined into "this
frame", then you that next frame won't have a computed id yet.  You have
to go past that to find the next non-inline frame, which will have a
computed id.

In other cases, it's fine to store the id of an inline frame as the
"next frame id" in a register struct value.  When trying to unwind a
register from it, it will just call inline_frame_prev_register, which
will forward the request to the next next frame, until we hit the next
physical frame.

I think it would make things simpler to just never store the id of an
inline frame as the next frame id of register struct values, and go with
the first next non-inline frame directly.  This way, we don't have to
wonder which code paths have to skip inline frames when creating
register values and which don't.

So, change value::allocate_register_lazy to do that work, and remove the
loops for the callers that did it.

Change-Id: Ic88115dac49dc14e3053c95f92050062b24b7310
2023-12-24 11:16:58 -05:00
Simon Marchi
78f2fd84e8 gdb: remove VALUE_REGNUM, add value::regnum
Remove VALUE_REGNUM, replace it with a method on struct value.  Set
`m_location.reg.regnum` directly from value::allocate_register_lazy,
which is fine because allocate_register_lazy is a static creation
function for struct value.

Change-Id: Id632502357da971617d9dce1e2eab9b56dbcf52d
2023-12-24 11:15:01 -05:00
Simon Marchi
8b31004bd8 gdb: remove VALUE_NEXT_FRAME_ID, add value::next_frame_id
Remove VALUE_NEXT_FRAME_ID, replace it with a method on struct value.  Set
`m_location.reg.next_frame_id` directly from value::allocate_register_lazy,
which is fine because allocate_register_lazy is a static creation
function for struct value.

Change-Id: Ic9f0f239c166a88dccfee836f9f51871e67548e6
2023-12-24 10:38:06 -05:00
Simon Marchi
306f960b49 gdb: implement address_from_register using value_from_register
As explained in the comment removed by the previous commit "gdb: pass
non-nullptr frame to gdbarch_value_from_register in
address_from_register", address_from_register copies some implementation
bits from value_from_register:

   /* This routine may be called during early unwinding, at a time
      where the ID of FRAME is not yet known.  Calling value_from_register
      would therefore abort in get_frame_id.  However, since we only need
      a temporary value that is never used as lvalue, we actually do not
      really need to set its VALUE_NEXT_FRAME_ID.  Therefore, we re-implement
      the core of value_from_register, but use the null_frame_id.  */

This is no longer relevant, since we now create a value with a valid next
frame id, so change address_from_register to use value_from_register.

Change-Id: I189bd96f28735ed9f47750ffd73764c459ec6f43
2023-12-24 09:02:08 -05:00
Simon Marchi
c465f43037 gdb: remove read_frame_register_value's frame parameter
By now, all register struct values should have a valid next frame id
(assuming they are created using value::allocate_register or
value::allocate_register_lazy), so there should be no need to pass a
frame alongside the value to read_frame_register_value.  Remove the
frame parameter and adjust read_frame_register_value accordingly.

While at it, make read_frame_register_value static, it's only used in
findvar.c.

Change-Id: I118959ef8c628499297c67810916e8ba9934bfac
2023-12-24 09:02:08 -05:00
Simon Marchi
8ada4c640b gdb: add type parameter to value::allocate_register and add value::allocate_register_lazy
Some places that create register struct values don't use register_type
to obtain the value type.  This prevents them from using the current
version of value::allocate_register.  One spot (value_of_register_lazy)
also creates a lazy register value.

Add a value::allocate_register_lazy method.  Add some type parameters
to value::allocate_register and value::allocate_register_lazy, to let
the caller specify the type to use for the value.  The parameters
default to nullptr, in which case we use register_type to obtain the
type.

Change-Id: I640ec0a5a0f4a55eba12d515dbfd25933229f8ec
2023-12-24 09:02:08 -05:00
Simon Marchi
9960c5d0a0 gdb: pass non-nullptr frame to gdbarch_value_from_register in address_from_register
address_from_register used to pass null_frame_id to
gdbarch_value_from_register as "this frame"'s id, because it's possible
for it to be called during unwind, when "this frame"'s id is not yet
known.  This create an oddity where those register struct values are
created without a valid next frame id.  I would much prefer for things
to be consistent and have all register struct values to have a valid
next frame id.

Since gdbarch_value_from_register takes a frame_info_ptr now, rather
than a frame_id, we can pass down "this frame", even if it doesn't have
a valid id.  gdbarch_value_from_register implementations can obtain the
next frame from it.

However, it's possible for the "this frame"'s next frame to be an
inline frame, inlined in "this frame", in which case that next frame's
id is also not known.  So, loop until we get to the next non-inline
frame (which is actually the frame where registers for "this frame" are
unwound from).  This is the same thing that we do in
value_of_register_lazy, for the same reason.  A later patch will factor
out this "while next frame is inline" loop to apply it to all register
struct values, so this is somewhat temporary.

Change-Id: If487c82620cc5a4a4ea5807f0a0bad80ab984078
2023-12-24 09:02:08 -05:00
Simon Marchi
9f02b3a024 gdb: pass frame_info_ptr to gdbarch_value_from_register
Pass a frame_info_ptr rather than a frame_id.  This avoids having to do
a frame lookup on the callee side, when we can just pass the frame down
directly.

I think this fixes a bug in rs6000-tdep.c where the id of the wrong
frame was set to `VALUE_NEXT_FRAME_ID (v)`.

Change-Id: I77039bc87ea8fc5262f16d0e1446515efa21c565
2023-12-24 09:02:08 -05:00
Simon Marchi
6658f874cf gdb: don't set frame id after calling cooked_read_value
I don't think that setting the next frame id is needed there, all code
paths in cooked_read_value do set it properly, AFAIK.

Change-Id: Idb9d9e6f89c2c95c5ebfeec2a63fde89ed84cf3d
2023-12-24 09:02:08 -05:00
Tom Tromey
2129106d20 Check for rogue DAP exceptions in test suite
This changes the test suite to look for rogue DAP exceptions in the
log file, and issue a "fail" if one is found.

Reviewed-By: Kévin Le Gouguec <legouguec@adacore.com>
2023-12-22 09:57:49 -07:00
Tom Tromey
0b32d22581 Avoid exception from attach in DAP
I noticed that the DAP attach test case (and similarly
remoted-dap.exp) had a rogue exception stack trace in the log.  It
turns out that an attach will generate a stop that does not have a
reason.

This patch fixes the problem in the _on_stop event listener by making
it a bit more careful when examining the event reason.  It also adds
some machinery so that attach stops can be suppressed, which I think
is the right thing to do.

Reviewed-By: Kévin Le Gouguec <legouguec@adacore.com>
2023-12-22 09:57:49 -07:00
Tom Tromey
dfc4bd461b Add DAP log level parameter
This adds a new parameter to control the DAP logging level.  By
default, "expected" exceptions are not logged, but the parameter lets
the user change this when more logging is desired.

This also changes a couple of spots to avoid logging the stack trace
for a DAPException.

This patch also documents the existing DAP logging parameter.  I
forgot to document this before.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>
Reviewed-By: Kévin Le Gouguec <legouguec@adacore.com>
2023-12-22 09:57:48 -07:00
Tom Tromey
2a89c9508e Introduce and use DAPException
This introduces a new DAPException class, and then changes various
spots in the DAP implementation to wrap "expected" exceptions in this.
This class will help detect rogue exceptions caused by bugs in the
implementation.

Reviewed-By: Kévin Le Gouguec <legouguec@adacore.com>
2023-12-22 09:57:30 -07:00
Kévin Le Gouguec
54ede87e19 gdb: fix refactoring hiccup in rs6000_register_to_value
In 2023-12-14 "gdb: make get_frame_register_bytes take the next frame"
(9fc79b4236), *_register_to_value functions were made to (a) call
get_next_frame_sentinel_okay (frame) (b) pass that next frame to
get_frame_register_bytes.

Step (b) was omitted for rs6000-tdep.c; this manifests as a regression on
PPC platforms for e.g. O2_float_param: instead of seeing…

  Temporary breakpoint 1, callee.increment (val=val@entry=99.0, msg=...) at callee.adb:19

… we get "optimized_out" for val.  Passing next_frame to
get_frame_register_bytes fixes the issue.

Approved-By: Simon Marchi <simon.marchi@efficios.com>
2023-12-22 17:19:29 +01:00
Tom Tromey
eb6476e2db Add 'program' to DAP 'attach' request
In many cases, it's not possible for gdb to discover the executable
when a DAP 'attach' request is used.  This patch lets the IDE supply
this information.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>
2023-12-22 09:05:17 -07:00