Roland McGrath [Fri, 21 Mar 2025 02:17:20 +0000 (19:17 -0700)]
ld: Support RELRO in aarch64-elf target
Other *-elf targets set COMMONPAGESIZE in emulparams/*.sh and so
enable `-z relro` and related features. Make aarch64-elf match.
There is no reason to think that a "generic ELF" target should
have any particular set of features disabled.
Tom de Vries [Thu, 20 Mar 2025 11:37:04 +0000 (12:37 +0100)]
[gdb/testsuite] Add missing returns in gdb.threads/infcall-from-bp-cond-simple.c
While investigating PR32785 I noticed a missing return statement in
worker_func, and compiling with -Wreturn-type showed another in
function_that_segfaults:
...
$ gcc gdb/testsuite/gdb.threads/infcall-from-bp-cond-simple.c -Wreturn-type
infcall-from-bp-cond-simple.c: In function ‘function_that_segfaults’:
infcall-from-bp-cond-simple.c:46:1: warning: \
control reaches end of non-void function [-Wreturn-type]
46 | }
| ^
infcall-from-bp-cond-simple.c: In function ‘worker_func’:
infcall-from-bp-cond-simple.c:58:1: warning: \
control reaches end of non-void function [-Wreturn-type]
58 | }
| ^
...
Tom de Vries [Thu, 20 Mar 2025 10:16:59 +0000 (11:16 +0100)]
[gdb/build] Fix build with gcc 9
Since commit a691853148f ("gdb/python: introduce gdbpy_registry"), when
building gdb with gcc 9, I run into:
...
In file included from gdb/varobj.c:38:0:
gdb/python/python-internal.h:1211:47: error: expected ‘;’ before ‘<’ token
using StorageKey = typename registry<O>::key<Storage>;
^
...
due to this code:
...
template <typename Storage>
class gdbpy_registry
{
...
template<typename O>
using StorageKey = typename registry<O>::key<Storage>;
As an experiment, I tried out eliminating the type alias:
...
template<typename O>
Storage *get_storage (O *owner,
const typename registry<O>::key<Storage> &key) const
{ ... }
...
and got instead:
...
In file included from gdb/varobj.c:38:0:
gdb/python/python-internal.h:1211:63: error: non-template ‘key’ used as template
Storage *get_storage (O *owner,
const typename registry<O>::key<Storage> &key) const
^~~
gdb/python/python-internal.h:1211:63: note: use ‘registry<O>::template key’ \
to indicate that it is a template
...
Following that suggestion, I tried:
...
template<typename O>
Storage *
get_storage (O *owner,
const typename registry<O>::template key<Storage> &key) const
{ ... }
...
which fixed the problem.
Likewise, adding the template keyword in the type alias fixes the original
problem, so fix it like that.
Sam James [Wed, 19 Mar 2025 22:53:36 +0000 (22:53 +0000)]
gcore: quote PKGVERSION
Same as 3bed686102cb14552d2ed1b83336453d7ce0dd47. I didn't hit an issue
here -- I think because my /bin/sh is dash and gdb-add-index has a /bin/sh
shebang, while gcore uses bash, but it's still worth fixing (we certainly
do NOT want this to be an array).
Sam James [Wed, 19 Mar 2025 22:44:10 +0000 (22:44 +0000)]
gdb-add-index: quote PKGVERSION
In Gentoo, we configure our gdb with `--with-pkgversion=` with
"Gentoo VERSION XXXX" where XXX depends on patching (not that we patch
gdb really these days) or vanilla.
Jan Vrany [Wed, 19 Mar 2025 21:12:53 +0000 (21:12 +0000)]
gdb/python: convert gdb.Symtab to use gdbpy_registry
This commit converts gdb.Symtab to use gdbpy_registry for lifecycle
management. Since gdb.Symtab only holds on the struct symtab * (and
prev/next links) the default invalidator can be used.
Jan Vrany [Wed, 19 Mar 2025 21:12:53 +0000 (21:12 +0000)]
gdb/python: convert gdb.Symbol to use gdbpy_registry
This commit converts gdb.Symbol to use gdbpy_registry for lifecycle
management. Since gdb.Symbol only holds on the struct symbol * (and
prev/next links) the default invalidator can be used.
Jan Vrany [Wed, 19 Mar 2025 21:12:53 +0000 (21:12 +0000)]
gdb/python: introduce gdbpy_registry
This commit introduces new template class gdbpy_registry to simplify
Python object lifecycle management. As of now, each of the Python
object implementations contain its own (copy of) lifecycle management
code that is largely very similar. The aim of gdbpy_registry is to
factor out this code into a common (template) class in order to simplify
the code.
Jan Vrany [Wed, 19 Mar 2025 21:12:53 +0000 (21:12 +0000)]
gdb/python: do not hold on gdb.Type object from gdb.Value
Previous commit changed type_to_type_object() so each time it is
called with particular struct value* it returns the same object.
Therefore there's no longer need to hold on type objects (gdb.Type)
from struct value_object in order to preserve identity of gdb.Type
objects held in value_object::type and value_object::dynamic_type
members. This in turn allowed for some simplification in various
functions.
While at it I changed a couple of NULLs to nullptrs.
Jan Vrany [Wed, 19 Mar 2025 21:12:53 +0000 (21:12 +0000)]
gdb/python: preserve identity for gdb.Type objects
This commit changes type_to_type_object() so that each it is called
with a particular struct type * it returns the very same gdb.Type
object.
This is done in the same way as for gdb.Symtab objects in earlier commit
("gdb/python: preserve identity for gdb.Symtab objects") except that
types may be either objfile-owned or arch-owned.
Prior this commit, arch-owned objects we not put into any list (like
objfile-owned ones) so they could not be easily looked up. This commit
changes the code so arch-owned list are put into per-architecture list
which is then used (solely) for looking up arch-owned gdb.Type.
Another complication comes from the fact that when objfile is about to
be freed, associated gdb.Type instances are not merely invalidated
(like it is done with gdb.Symtab or gdb.Symbol objects) but instead the
type is copied and the copy is arch-owned. So we need two different
"deleters", one for objfile-owned types that copies the type (as before)
and then insert the object to per-architecture list and another one
for arch-owned types.
Jan Vrany [Wed, 19 Mar 2025 21:12:53 +0000 (21:12 +0000)]
gdb/python: do not hold on gdb.Symtab object from gdb.Symtab_and_line
Previous commit changed symtab_to_symtab_object() so each time it is
called with particula struct symtab* it returns the same object.
Therefore there's no longer need to hold on symtab object (gdb.Symtab)
from struct sal_object in order to preserve identity of Symtab object
held in gdb.Symtab_and_line.symtab property. This in turn allowed for
some simplification in various functions.
While at it I changed a couple of NULLs to nullptrs.
Jan Vrany [Wed, 19 Mar 2025 21:12:53 +0000 (21:12 +0000)]
gdb/python: preserve identity for gdb.Symbol objects
This commit changes symbol_to_symbol_object() so that each it is called
with a particular struct symbol * it returns the very same gdb.Symbol
object.
This is done in the same way as for gdb.Symtab objects in earlier commit
("gdb/python: preserve identity for gdb.Symtab objects") except that
symbols may be either objfile-owned or arch-owned.
Prior this commit, arch-owned objects we not put into any list (like
objfile-owned ones) so they could not be easily looked up. This commit
changes the code so arch-owned list are put into per-architecture list
which is then used (solely) for looking up arch-owned gdb.Symbol.
Simon Marchi [Mon, 10 Mar 2025 15:10:48 +0000 (11:10 -0400)]
gdb: handle INTERNALVAR_FUNCTION in clear_internalvar
While checking the list of leaks reported by ASan, I found that
clear_internalvar doesn't free the internal_function object owned by the
internalvar when the internalvar is of kind INTERNALVAR_FUNCTION, fix
that.
Simon Marchi [Mon, 10 Mar 2025 15:10:47 +0000 (11:10 -0400)]
gdb: clear internalvar on destruction
The data associated to an internalvar is destroyed when changing the
kind of the internalvar, but not when it is destroyed. Fix that by
calling clear_internalvar in ~internalvar.
A move constructor becomes needed to avoid freeing things multiple times
when internalvars are moved (and if we forget it, clang helpfully gives
us a -Wdeprecated-copy-with-user-provided-dtor warning).
Simon Marchi [Mon, 10 Mar 2025 15:10:46 +0000 (11:10 -0400)]
gdb: C++-ify internal_function
Change the `name` field to std::string, add constructor. Remove
function `create_internal_function`, since it becomes a trivial wrapper
around the constructor.
Andrew Burgess [Thu, 13 Feb 2025 15:39:31 +0000 (15:39 +0000)]
gdb/python: new styling argument to gdb.execute
Currently, gdb.execute emits styled output when the command is sending
its output to GDB's stdout, and produces unstyled output when the
output is going to a string.
But it is not unreasonable that a user might wish to capture styled
output from a gdb.execute call, for example, the user might want to
display the styled output are part of some larger UI output block.
At the same time, I don't think it makes sense to always produce
styled output when capturing the output in a string; if what the user
wants is to parse the output, then the style escape sequences make
this far harder.
I propose that gdb.execute gain a new argument 'styling'. When False
we would always produce unstyled output, and when True we would
produce styled output if styling is not disabled by some other means.
For example, if GDB's 'set style enabled' is off, then I think
gdb.execute() should respect that. My assumption here is that
gdb.execute() might be executed by some extension. If the extension
thinks "styled output world work here", but the user hates styled
output, and has turned it off, then the extension should not be
forcing styled output on the user.
I chose 'styling' instead of 'styled' as the Python argument name
because we already use 'styling' in gdb.Value.format_string, and we
don't use 'styled' anywhere else. This is only a little bit of
consistency, but I still think it's a good thing.
The default for 'styling' will change depending on where the output is
going. When gdb.execute is sending the output to GDB's stdout then
the default for 'styling' is True. When the output is going to a
string, then the default for 'styling' will be False. Not only does
this match the existing behaviour, but I think this makes sense. By
default we assume that output captured in a string is going to be
parsed, and therefore styling markup is unhelpful, while output going
to stdout should receive styling.
This fixes part of the problem described in PR gdb/32676. That bug
tries to capture styled source listing in a string, which wasn't
previously possible.
There are some additional issues with capturing source code; GDB
caches the source code in the source code cache. However, GDB doesn't
check if the cached content is styled or not. As a consequence, if
the first time the source of a file is shown it is unstyled, then the
cached will hold the unstyled source code, and future requests will
return that unstyled source. I'll address this issue in a separate
patch.
Andrew Burgess [Tue, 4 Mar 2025 17:48:37 +0000 (17:48 +0000)]
gdb: show full shared library memory range in 'info sharedlibrary'
On GNU/Linux (and other targets that use solib-svr4.c) the 'info
sharedlibrary' command displays the address range for the .text
section of each library. This is a fallback behaviour implemented in
solib_map_sections (in solib.c), for targets which are not able to
provide any better information.
The manual doesn't really explain what the address range given means,
and the .text fallback certainly isn't described. The manual for
'info sharedlibrary' just says:
'info share REGEX'
'info sharedlibrary REGEX'
Print the names of the shared libraries which are currently loaded
that match REGEX. If REGEX is omitted then print all shared
libraries that are loaded.
In this commit I propose that we should change GDB so that the full
library address range is listed for GNU/Linux (and other solib-svr4
targets). Though it is certainly useful to know where the .text for a
library is, not all code is placed into the .text section, and data,
or course, is stored elsewhere, so the choice of .text, though not a
crazy default, is still a pretty arbitrary choice.
We do also have 'maintenance info sections', which can be used to find
the location of a specific section. This is of course, a maintenance
command, but we could make this into a real user command if we wanted,
so the information lost by this change to 'info sharedlibrary' is
still available if needed.
There is one small problem. After this commit, GDB is still under
reporting the extents of some libraries, in some cases.
What I observe is that sometimes, for reasons that I don't currently
understand, the run-time linker will over allocate memory for the .bss
like sections, e.g. the ELF says that 1 page is required, but 2 or 4
pages will be allocated instead. As a result, GDB will under report
the extent of the library, with the end address being lower than
expected. This isn't always the case though, in many cases the
allocates are as I would expect, and GDB reports the correct values.
However, as we have been under reporting for many years, I think this
update, which gets things a lot closer to reality, is a big step in
the right direction. We can always improve the results more later
on if/when the logic behind the over allocations become clearer.
For testing I've compared the output of 'info proc mappings' with the
output of 'info sharedlibrary' (using a script), using GDB to debug
itself, on Fedora Linux running on AArch64, PPC64, S390, and X86-64,
and other than the over allocation problem described above, the
results all look good to me.
Reviewed-By: Eli Zaretskii <eliz@gnu.org> Approved-By: Simon Marchi <simon.marchi@efficios.com>
Simon Marchi [Tue, 18 Mar 2025 13:48:51 +0000 (09:48 -0400)]
gdb/dwarf: use gdb::unordered_set for cooked_index_storage::m_reader_hash
Replace an htab with gdb::unordered_set. I think we could also use the
dwarf2_per_cu pointer itself as the identity, basically have the
functional equivalent of:
Simon Marchi [Tue, 18 Mar 2025 03:16:25 +0000 (23:16 -0400)]
gdb/dwarf: remove type_unit_group
The type_unit_group is an indirection between a stmt_list_hash (possible
dwo_unit + line table section offset) and a type_unit_group_unshareable
that provides no real value. In dwarf2_per_objfile, we maintain a
stmt_list_hash -> type_unit_group mapping, and in dwarf2_per_objfile, we
maintain a type_unit_group_unshareable mapping. The type_unit_group
type is empty and only exists to have an identity and to be a link
between the two mappings.
This patch changes it so that we have a single stmt_list_hash ->
type_unit_group_unshareable mapping.
Regression tested on Debian 12 amd64 with a bunch of DWARF target
boards.
Change-Id: I9c5778ecb18963f353e9dd058e0f8152f7d8930c Approved-By: Tom Tromey <tom@tromey.com>
Simon Marchi [Tue, 18 Mar 2025 03:16:24 +0000 (23:16 -0400)]
gdb/dwarf: use gdb::unordered_map for dwarf2_per_bfd::{quick_file_names_table,type_unit_groups}
Change these two hash tables to use gdb::unordered_map. I changed these
two at the same time because they both use the same key, a
stmt_list_hash. Unlike other previous patches that used a
gdb::unordered_set, use an unordered_map here because the key isn't
found in the element itself (well, it was before, because of how htab
works, but it didn't need to be).
You'll notice that the type_unit_group structure is empty. That
structure isn't really needed. It is removed in the following patch.
Regression tested on Debian 12 amd64 with a bunch of DWARF target
boards.
Change-Id: Iec2289958d0f755cab8198f5b72ecab48358ba11 Approved-By: Tom Tromey <tom@tromey.com>
Tom Tromey [Thu, 6 Feb 2025 16:32:48 +0000 (09:32 -0700)]
Introduce and use attribute::unsigned_constant
This introduces a new 'unsigned_constant' method on attribute. This
method can be used to get the value as an unsigned number. Unsigned
scalar forms are handled, and signed scalar forms are handled as well
provided that the value is non-negative.
Several spots in the reader that expect small DWARF-defined constants
are updated to use this new method.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680 Approved-By: Simon Marchi <simon.marchi@efficios.com>
Tom Tromey [Thu, 6 Feb 2025 17:08:38 +0000 (10:08 -0700)]
Rename form_is_signed to form_is_strictly_signed
This renames attribute::form_is_signed to form_is_strictly_signed. I
think this more accurately captures what it does: it says whether a
form will always use signed data -- not whether a form might use
signed data, which DW_FORM_data* do depending on context.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680 Approved-By: Simon Marchi <simon.marchi@efficios.com>
Tom de Vries [Tue, 18 Mar 2025 15:22:02 +0000 (16:22 +0100)]
[gdb/testsuite] Fix gdb.base/enum_cond.exp on arm-linux
On arm-linux, I run into:
...
gdb compile failed, ld: warning: enum_cond.o uses variable-size enums yet \
the output is to use 32-bit enums; use of enum values across objects may fail
UNTESTED: gdb.base/enum_cond.exp: failed to compile
...
Fix this by using -nostdlib.
Tested on arm-linux and x86_64-linux.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Simon Marchi [Mon, 17 Mar 2025 14:34:30 +0000 (10:34 -0400)]
gdb/dwarf: set m_top_level_die directly in read_cutu_die_from_dwo
read_cutu_die_from_dwo currently returns the dwo's top-level DIE through
a parameter. Following the previous patch, all code paths end up
setting m_top_level_die. Simplify this by having read_cutu_die_from_dwo
set m_top_level_die directly. I think it's easier to understand,
because there's one less indirection to follow.
Change-Id: Ib659f1d2e38501a8fe2b5dd0ca2add3ef55e8d60 Approved-By: Tom Tromey <tom@tromey.com>
Simon Marchi [Mon, 17 Mar 2025 14:34:29 +0000 (10:34 -0400)]
gdb/dwarf: fix spurious error when encountering dummy CU
I built an application with -gsplit-dwarf (i.e. dwo), and some CUs are
considered "dummy" by the DWARF reader. That is, the top-level DIE
(DW_TAG_compile_unit) does not have any children. Here's the skeleton:
0x0000c0cb: Compile Unit: length = 0x0000001d, format = DWARF32, version = 0x0005, unit_type = DW_UT_skeleton, abbr_offset = 0x529b, addr_size = 0x08, DWO_id = 0x0ed2693dd2a756dc (next unit at 0x0000c0ec)
When loading the binary in GDB, I see some warnings:
$ ./gdb -q -nx --data-directory=data-directory -ex 'maint set dwarf sync on' -ex "file /home/simark/src/tdesktop/build-relwithdebuginfo-split-nogz/telegram-desktop"
Reading symbols from /home/simark/src/tdesktop/build-relwithdebuginfo-split-nogz/telegram-desktop...
DWARF Error: unexpected tag 'DW_TAG_skeleton_unit' at offset 0xc0cb
DWARF Error: unexpected tag 'DW_TAG_skeleton_unit' at offset 0xc152
DWARF Error: unexpected tag 'DW_TAG_skeleton_unit' at offset 0xc194
DWARF Error: unexpected tag 'DW_TAG_skeleton_unit' at offset 0xc1b5
(gdb)
It turns out that these errors are not really justified. What happens
is:
- cutu_reader::read_cutu_die_from_dwo return 0, indicating that the CU
is "dummy"
- back in cutu_reader::cutu_reader, we omit setting m_top_level_die to
the DIE from the dwo file, meaning that m_top_level_die keeps
pointing to the DIE from the main file (DW_TAG_skeleton_unit)
- later, in cutu_reader::prepare_one_comp_unit, there is a check that
m_top_level_die->tag is one of DW_TAG_{compile,partial,type}_unit,
which triggers
My proposal to fix this is to set m_top_level_die even if the CU is
dummy. Even if the top-level DIE does not have any children, I don't
see any reason to leave cutu_reader::m_top_level_die in a different
state than when the CU is not dummy.
While at it, set m_dummy_p directly in read_cutu_die_from_dwo, instead
of returning a value and having the caller do it. This is all inside
cutu_reader anyway.
Change-Id: I483a68a369bb461a8dfa5bf2106ab1d6a0067198 Approved-By: Tom Tromey <tom@tromey.com>
Andrew Burgess [Sat, 2 Nov 2024 17:35:14 +0000 (17:35 +0000)]
gdb: split up construct_inferior_arguments
The function construct_inferior_arguments (gdbsupport/common-inferior.cc)
currently escapes all special shell characters. After this commit
there will be two "levels" of quoting:
1. The current "full" quoting, where all posix shell special
characters are quoted, and
2. a new "reduced" quoting, where only the characters that GDB sees
as special (quotes and whitespace) are quoted.
After this, almost all construct_inferior_arguments calls will use the
"full" quoting, which is the current quoting. The "reduced" quoting
will be used in this commit to restore the behaviour that was lost in
the previous commit (more details below).
In the future, the reduced quoting will be useful for some additional
inferior argument that I have planned. I already posted my full
inferior argument work here:
But that series is pretty long, and wasn't getting reviewed, so I'm
posted the series in parts now.
Before the previous commit, GDB behaved like this:
$ gdb -eiex 'set startup-with-shell off' --args /tmp/exec '$FOO'
(gdb) show args
Argument list to give program being debugged when it is started is "$FOO".
Notice that with 'startup-with-shell' off, the argument was left as
just '$FOO'. But after the previous commit, this changed to:
$ gdb -eiex 'set startup-with-shell off' --args /tmp/exec '$FOO'
(gdb) show args
Argument list to give program being debugged when it is started is "\$FOO".
Now the '$' is escaped with a backslash. This commit restores the
original behaviour, as this is (currently) the only way to unquoted
shell special characters into arguments from the GDB command line.
The series that I listed above includes a new command line option for
GDB which provides a better approach for controlling the quoting of
special shell characters, but that work requires these patches to be
merged first.
I've split out the core of construct_inferior_arguments into the new
function escape_characters, which takes a set of characters to escape.
Then the two functions escape_shell_characters and
escape_gdb_characters call escape_characters with the appropriate
character sets.
Finally, construct_inferior_arguments, now takes a boolean which
indicates if we should perform full shell escaping, or just perform
the reduced escaping.
I've updated all uses of construct_inferior_arguments to pass a
suitable value to indicate what escaping to perform (mostly just
'true', but one case in main.c is different), also I've updated
inferior::set_args to take the same boolean flag, and pass it through
to construct_inferior_arguments.
gdb: Support some escaping of args with startup-with-shell being off
nat/fork-inferior.c was updated such that when we are starting an
inferior without a shell we now remove escape characters. The
benefits of this are explained in that commit, but having made this
change we can now make an additional change.
Currently, in construct_inferior_arguments, when startup_with_shell is
false we construct the inferior argument string differently than when
startup_with_shell is true; when true we apply some escaping to
special shell character, when false we don't.
This commit simplifies construct_inferior_arguments by removing the
!startup_with_shell case, and instead we now apply escaping in all
cases. This is fine because, thanks to the above commit the escaping
will be correctly removed again when we call into nat/fork-inferior.c.
We should think of construct_inferior_arguments and
nat/fork-inferior.c as needing to cooperate in order for argument
handling to work correctly.
construct_inferior_arguments converts a list of separate arguments
into a single string, and nat/fork-inferior.c splits that single
string back into a list of arguments. It is critical that, if
nat/fork-inferior.c is expecting to remove a "layer" of escapes, then
construct_inferior_arguments must add that expected "layer",
otherwise, we end up stripping more escapes than expected.
The great thing (I think) about the new configuration, is that GDB no
longer cares about startup_with_shell at the point the arguments are
being setup. We only care about startup_with_shell at the point that
the inferior is started. This means that a user can set the inferior
arguments, and then change the startup-with-shell setting, and GDB
will do what they expect.
Under the previous system, where construct_inferior_arguments changed
its behaviour based on startup_with_shell, the user had to change the
setting, and then set the arguments, otherwise, GDB might not do what
they expect.
There is one slight issue with this commit though, which will be
addressed by the next commit.
For GDB's native targets construct_inferior_arguments is reached via
two code paths; first when GDB starts and we combine arguments from
the command line, and second when the Python API is used to set the
arguments from a sequence. It's the command line argument handling
which we are interested in.
Consider this:
$ gdb --args /tmp/exec '$FOO'
(gdb) show args
Argument list to give program being debugged when it is started is "\$FOO".
Notice that the argument has become \$FOO, the '$' is now quoted.
This is because, by quoting the argument in the shell command that
started GDB, GDB was passed a literal $FOO with no quotes. In order
to ensure that the inferior sees this same value, GDB added the extra
escape character. When GDB starts with a shell we pass \$FOO, which
results in the inferior seeing a literal $FOO.
But what if the user _actually_ wanted to have the shell GDB uses to
start the inferior expand $FOO? Well, it appears this can't be done
from the command line, but from the GDB prompt we can just do:
(gdb) set args $FOO
(gdb) show args
Argument list to give program being debugged when it is started is "$FOO".
And now the inferior will see the shell expanded version of $FOO.
It might seem like we cannot achieve the same result from the GDB
command line, however, it is possible with this trick:
$ gdb -eiex 'set startup-with-shell off' --args /tmp/exec '$FOO'
(gdb) show args
Argument list to give program being debugged when it is started is "$FOO".
(gdb) show startup-with-shell
Use of shell to start subprocesses is off.
And now the $FOO is not escaped, but GDB is no longer using a shell to
start the inferior, however, we can extend our command line like this:
$ gdb -eiex 'set startup-with-shell off' \
-ex 'set startup-with-shell on' \
--args /tmp/exec '$FOO'
(gdb) show args
Argument list to give program being debugged when it is started is "$FOO".
(gdb) show startup-with-shell
Use of shell to start subprocesses is on.
Use an early-initialisation option to disable startup-with-shell, this
is done before command line argument processing, then a normal
initialisation option turns startup-with-shell back on after GDB has
processed the command line arguments!
Is this useful? Yes, absolutely. Is this a good user experience?
Absolutely not. And I plan to add a new command line option to
GDB (and gdbserver) that will allow users to achieve the same
result (this trick doesn't work in gdbserver as there's no
early-initialisation there) without having to toggle the
startup-with-shell option. The new option can be found in the series
here:
The problem is that, that series is pretty long, and getting it
reviewed is just not possible. So instead I'm posting the individual
patches in smaller blocks, to make reviews easier.
So, what's the problem? Well, by removing the !startup_with_shell
code path from GDB, there is no longer a construct_inferior_arguments
code path that doesn't quote inferior arguments, and so there's no
longer a way, from the command line, to set an unquoted '$FOO' as an
inferior argument. Obviously, this can still be done from GDB's CLI
prompt.
The trick above is completely untested, so this regression isn't going
to show up in the testsuite.
And the breakage is only temporary. In the next commit I'll add a fix
which restores the above trick.
Of course, I hope that this fix will itself, only be temporary. Once
the new command line options that I mentioned above are added, then
the fix I add in the next commit can be removed, and user should start
using the new command line option.
After this commit a whole set of tests that were added as xfail in the
above commit are now passing.
A change similar to this one can be found in this series:
which I reviewed before writing this patch. I don't think there's any
one patch in that series that exactly corresponds with this patch
though, so I've listed the author of the original series as co-author
on this patch.
Co-Authored-By: Michael Weghorn <m.weghorn@posteo.de>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28392
Tom Tromey [Mon, 17 Mar 2025 17:58:03 +0000 (11:58 -0600)]
Preserve a local variable in a gdb test
I found another Ada test where LLVM optimizes away an unused local
variable. This patch fixes this problem -- but note the test now
fails for a different (currently expected) reason.
Tom Tromey [Thu, 13 Mar 2025 22:44:05 +0000 (16:44 -0600)]
Use gdb unordered map in tui-io.c
This changes tui.c to use gdb::unordered_map. ui_file_style::color is
changed a little as well; operator< is no longer needed, but a simple
hash function is added.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Tom Tromey [Tue, 11 Mar 2025 17:22:05 +0000 (11:22 -0600)]
Use gdb unordered set and map in Python layer
This changes a couple of files in the Python layer to use
gdb:unordered_set and gdb::unordered_map. Another use exists but I
think it is being handled by Jan's series.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Tom de Vries [Tue, 18 Mar 2025 07:45:54 +0000 (08:45 +0100)]
[gdb/tdep] Use SYSCALL_MAP_RENAME for aarch64 and loongarch
There are currently two functions using macros SYSCALL_MAP and
UNSUPPORTED_SYSCALL_MAP: aarch64_canonicalize_syscall, and
loongarch_canonicalize_syscall.
Here [1] I propose to do the same in i386_canonicalize_syscall, using one
additional macro: SYSCALL_MAP_RENAME.
Add the same macro in aarch64_canonicalize_syscall and
loongarch_canonicalize_syscall, and use it to map aarch64_sys_mmap and
loongarch_sys_mmap to gdb_sys_mmap2.
While we're at it:
- reformat the macro definitions to be more readable,
- add missing macro undefs in aarch64_canonicalize_syscall, and
- fix indentation in aarch64_canonicalize_syscall.
No functional changes.
Tested by rebuilding on x86_64-linux.
Reviewed-By: Alexandra Petlanova Hajkova <ahajkova@redhat.com>
[1] https://sourceware.org/pipermail/gdb-patches/2025-March/216230.html
Jerry Zhang Jian [Mon, 17 Mar 2025 12:16:35 +0000 (20:16 +0800)]
RISC-V: Support pointer masking extension 1.0
- Adding Ssnpm, Smnpm, Smmpm, Sspm, and Supm
- No new CSR added
- Pointer masking only applies to RV64
- Ref: https://github.com/riscv/riscv-j-extension/releases/download/pointer-masking-ratified/pointer-masking-ratified.pdf
Signed-off-by: Jerry Zhang Jian <jerry.zhangjian@sifive.com>
Jin Ma [Mon, 17 Mar 2025 06:07:35 +0000 (14:07 +0800)]
RISC-V: Add extension XTheadVdot for T-Head VECTOR vendor extension [1]
T-Head has a range of vendor-specific instructions. Therefore
it makes sense to group them into smaller chunks in form of
vendor extensions.
This patch adds the additional extension "XTheadVdot" based on the
"V" extension, and it provides four 8-bit multiply and add with
32-bit instructions for the "v" extension. The 'th' prefix and the
"XTheadVector" extension are documented in a PR for the
RISC-V toolchain conventions ([2]).
Nelson Chu [Thu, 13 Mar 2025 02:31:36 +0000 (10:31 +0800)]
RISC-V: Avoid parsing arch string repeatedly for dis-assembler
Since we now always generate $x+isa for now, these would increase the
dis-assemble time by parsing the same architecture string repeatedly. We
already have `arch_str' field into `subset_list' to record the current
architecture stirng, but it's only useful for assembler, since dis-assembler
and linker don't need it before. Now for dis-assembler, we just need to
update the `arch_str' after parsing the architecture stirng, and then avoid
parsing repeatedly if the strings are the same.
Nelson Chu [Thu, 13 Mar 2025 02:31:35 +0000 (10:31 +0800)]
RISC-V: Free the returned string of riscv_arch_str if we call it multiple times
The string returned from riscv_arch_str is allocated by xmalloc, so once we
called it multiple times, we should keep the newest one for the output elf
architecture attribute, but free the remaining unused strings.
Nelson Chu [Thu, 13 Mar 2025 02:31:34 +0000 (10:31 +0800)]
RISC-V: Fixed riscv_update_subset1 returning wrong boolean value
The riscv_update_subset1 returning wrong boolean value if the
riscv_parse_check_conflicts isn't called, though the current return value
doesn't really useful.
Simon Marchi [Sat, 15 Mar 2025 22:13:41 +0000 (18:13 -0400)]
gdbsupport: add some -Wunused-* warning flags
Add a few -Wunused-* diagnostic flags that look useful. Some are known
to gcc, some to clang, some to both. Fix the fallouts.
-Wunused-const-variable=1 is understood by gcc, but not clang.
-Wunused-const-variable would be undertsood by both, but for gcc at
least it would flag the unused const variables in headers. This doesn't
make sense to me, because as soon as one source file includes a header
but doesn't use a const variable defined in that header, it's an error.
With `=1`, gcc only warns about unused const variable in the main source
file. It's not a big deal that clang doesn't understand it though: any
instance of that problem will be flagged by any gcc build.
Change-Id: Ie20d99524b3054693f1ac5b53115bb46c89a5156 Approved-By: Tom Tromey <tom@tromey.com>
Andrew Burgess [Thu, 13 Mar 2025 16:29:07 +0000 (16:29 +0000)]
gdb-add-index: add --help and --version options
Update the gdb-add-index script to offer --help and --version options.
The script currently accepts the argument '-dwarf-5' with a single
leading '-'. As two '--' is more common for long options, the
preferred argument form is now '--dwarf-5', the docs have been
updated, and the new help text uses this form.
For backward compatibility, the old '-dwarf-5' form is still
accepted.
The new arguments are '--help' or '-h', but I also accept '-help' for
consistency with '-dwarf-5'. And likewise for the version argument.
Handling of the gdb-add-index script is done basically the same as for
gcore and gstack; we use config.status to create a .in file within the
build directory, which is then processed by the Makefile to create the
final script.
The difference with gdb-add-index is that I left the original script
as gdb/contrib/gdb-add-index.sh rather than renaming it to something
like gdb/contrib/gdb-add-index-1.in, which is how gcore and gstack are
handled (though they are not in the contrib directory).
The reason for this is that the contrib/cc-with-tweaks.sh script looks
for gdb-add-index.sh within the gdb/contrib/ source directory.
As the only reason we process gdb-add-index.sh into the build
directory is to support the PKGVERSION and VERSION variables, allowing
cc-with-tweaks to continue using the unprocessed version seems
harmless, and avoids having to change cc-with-tweaks.sh at all.
I tested that I can still run tests using the cc-with-gdb-index target
board, and that the installed gdb-add-index script correctly shows a
version number when asked.
Andrew Burgess [Mon, 17 Feb 2025 15:00:52 +0000 (15:00 +0000)]
gdb: make cli_styling static within cli/cli-style.c
The cli_styling variable is controlled by 'set style enabled on|off'
user setting, and is currently globally visible.
In a couple of places we access this variable directly, though in
ui-file.c the accesses are all performed through term_cli_styling(),
which is a function that wraps checking cli_styling along with a check
that GDB's terminal supports styling.
In a future commit, I'd plan to add a new parameter to gdb.execute()
which will allow styling to be temporarily suppressed. In an earlier
proposal, I made gdb.execute() disable styling by changing the value
of cli_styling, however, this approach has a problem.
If gdb.execute() is used to run 'show style enabled', the changing
cli_styling will change what is printed. Similarly, if gdb.execute()
is used to execute 'set style enabled on|off' then having
gdb.execute() save and restore the value of cli_styling will undo the
adjustment from 'set style enabled ...'.
So what I plan to do in the future, is add a new control flag which
can be used to temporarily disable styling.
To make this new control variable easier to add, lets force everyone
to call term_cli_styling() to check if styling is enabled or not. To
force everyone to use term_cli_styling() this commit makes cli_styling
static within gdb/cli/cli-style.c.
gdb/python: remove unused argument from builtin_disassemble
this commit fixes it.
I've also reworded the NEWS entry a little. Simon pointed out in
review that the unused argument was also documented in Python's help()
output, which I hadn't mentioned in the NEWS entry. I've updated the
NEWS entry to just highlight that the now removed argument was never
mentioned in the manual, I think that's all that really matters.
Simon Marchi [Mon, 17 Mar 2025 02:38:22 +0000 (22:38 -0400)]
gdb/dwarf: use gdb::unordered_set for seen_names
Direct replacement of an htab with a gdb::unordered_set.
Using a large test program, I see a small but consistent performance
improvement. The "file" command time goes on average from 7.88 to 7.73
seconds (~2%). To give a rough estimate of the scale of the test
program, the 8 seen_names hash tables (one for each worker thread) had
between 173846 and 866961 entries.
Change-Id: I0157cbd04bb55338bb1fcefd2690aeef52fe3afe Approved-By: Tom Tromey <tom@tromey.com>
Lucy Kingsbury [Sun, 16 Mar 2025 21:47:21 +0000 (17:47 -0400)]
Fix Guile pretty printer display hints
All 3 valid Guile pretty printer display hints are treated as the
value "string". As a result, if a printer specifies "array" or
"map", the output is instead formatted as a string.
Clément Chigot [Mon, 10 Mar 2025 15:56:02 +0000 (16:56 +0100)]
ld/testsuite: add gnu property section in nto-stack-note*
A GNU property section is now always generated when `-z stack-size` is
passed. This was probably introduced by GNU Property refactoring
within elfxx-aarch64.c.
gdb/python: implement the print_insn extension language hook
added the gdb.disassembler.builtin_disassemble Python API function.
By mistake, the implementation accepted two arguments, the second
being a "memory_source".
However, this second argument was never used, it was left over from an
earlier proposed version of the API.
Luckily, the only place the unused argument was documented was in the
NEWS file and in the output of `help(gdb.builtin_disassemble)`, and
neither of these locations really describe what the argument was, or
how it would be used. The manual only describes the first (actually
used) argument, so I think we are safe enough to delete the unused
argument.
This allows some additional cleanup, with the store for the argument
also being deleted.
As the NEWS file did originally document the second argument, I have
added a NEWS entry to explain the argument has now been removed.
This could potentially break users code if they somehow decided to
pass a second argument, however, fixing things is as simple as
removing the second (unused) argument.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Andrew Burgess [Fri, 14 Feb 2025 11:51:41 +0000 (11:51 +0000)]
gdb/python: handle non-utf-8 character from gdb.execute()
I noticed that it was not possible to return a string containing non
utf-8 characters using gdb.execute(). For example, using the binary
from the gdb.python/py-source-styling.exp test:
(gdb) file ./gdb/testsuite/outputs/gdb.python/py-source-styling/py-source-styling
Reading symbols from ./gdb/testsuite/outputs/gdb.python/py-source-styling/py-source-styling...
(gdb) set style enabled off
(gdb) list 26
21 int some_variable = 1234;
22
23 /* The following line contains a character that is non-utf-8. This is a
24 critical part of the test as Python 3 can't convert this into a string
25 using its default mechanism. */
26 char c[] = "�"; /* List this line. */
27
28 return 0;
29 }
(gdb) python print(gdb.execute('list 26', to_string=True))
Python Exception <class 'UnicodeDecodeError'>: 'utf-8' codec can't decode byte 0xc0 in position 250: invalid start byte
Error occurred in Python: 'utf-8' codec can't decode byte 0xc0 in position 250: invalid start byte
It is necessary to disable styling before the initial 'list 26',
otherwise the source will be passed through GNU source highlight, and
GNU source highlight seems to be smart enough to figure out the
character encoding, and convert it to UTF-8. This conversion is then
cached in the source cache, and the later Python gdb.execute call will
get back a pure UTF-8 string.
If source styling is disabled, then GDB caches the string without the
conversion to UTF-8, now the gdb.execute call gets back the string
with a non-UTF-8 character within it, and Python throws an error
during its attempt to create a string object.
I'm not, at this point, proposing a solution that tries to guess the
source file encoding, though I guess such a thing could be done.
Instead, I think we should make use of the host_charset(), as set by
the user with 'set host-charset ....' during the creation of the
Python string.
To do this, in execute_gdb_command, we should switch from
PyUnicode_FromString, which requires the input be a UTF-8 string, to
using PyUnicode_Decode, which allows GDB to specify the string
encoding. We will use host_charset().
With this done, it is now possible to list the file contents using
gdb.execute(), with the contents passing through a string:
(gdb) set host-charset ISO-8859-1
(gdb) python print(gdb.execute('list 26', to_string=True), end='')
21 int some_variable = 1234;
22
23 /* The following line contains a character that is non-utf-8. This is a
24 critical part of the test as Python 3 can't convert this into a string
25 using its default mechanism. */
26 char c[] = "À"; /* List this line. */
27
28 return 0;
29 }
(gdb)
There are already plenty of other places in GDB's Python code where we
use PyUnicode_Decode to create a string from something that might
contain user generated content, so I believe this is the correct
approach.
H.J. Lu [Thu, 13 Mar 2025 18:52:00 +0000 (11:52 -0700)]
elf: Clear the SEC_ALLOC bit for NOLOAD note sections
When generating an ELF output file, if a note section is marked as
NOLOAD, clear the SEC_ALLOC bit so that it won't be treated as an
SHF_ALLOC section, like a .bss style section.
PR ld/32787
* ld.texi: Update NOLOAD for ELF output files.
* ldlang.c (lang_add_section): Clear the SEC_ALLOC bit for NOLOAD
note sections for ELF output files.
* testsuite/ld-elf/pr32787.d: New file.
* testsuite/ld-elf/pr32787.t: Likewise.
Tom Tromey [Tue, 11 Mar 2025 15:28:42 +0000 (09:28 -0600)]
Remove std::hash specialization
C++11 initially omitted specialization of std::hash for enumeration
types, but this was rectified in LWG issue 2148. This patch removes a
redundant specialization. Tested by rebuilding.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Simon Marchi [Fri, 14 Mar 2025 04:32:55 +0000 (00:32 -0400)]
gdb/dwarf: assume that no dwarf2_cu exist when calling load_full_comp_unit
After staring at the code, I got convinced that it was not possible for
load_full_comp_unit to be called while a dwarf2_cu object exists in
per_objfile for this_cu. If you follow all callers of
load_full_comp_unit, you can see that all calls to load_full_comp_unit
(except one, see below) are gated one way or another by the fact that:
per_objfile->get_cu (per_cu) == nullptr
Some calls are gated by maybe_queue_comp_unit returning true. If it
returns true, then necessarily the dwarf2_cu is unset for that per_cu.
The spot that didn't seem to check for whether the dwarf2_cu is already
set before calling load_full_comp_unit is dw2_do_instantiate_symtab. It
didn't trigger when running the testsuite, but I could imagine a made up
case where the dwarf2_cu would already be set because we looked up a DIE
reference to it (follow_die_ref) for whatever reason. Then, something
would cause the symtab for that CU to be expanded and
dw2_do_instantiate_symtab to be called.
I added a check in that function, because it seemed prudent to do so.
All other load_cu calls are gated by this check, so it makes this call
look just like the others.
Finally, because all call sites that use cutu_reader::release_cu pass
nullptr for `existing_cu` (and therefore cutu_reader creates a new
dwarf2_cu), we know that cutu_reader::release_cu will always return a
non-nullptr value. Add an assert in it and remove checks in
load_full_comp_unit and read_signatured_type.
Change-Id: I496be34bd4bf7edfa38d5135cf4bc4ccd960abe2 Approved-By: Tom Tromey <tom@tromey.com>
Simon Marchi [Fri, 14 Mar 2025 04:32:53 +0000 (00:32 -0400)]
gdb/dwarf: assume that source_cu->dies is always set in follow_die_offset
After staring at the code for a while, I got convinced that it's not
possible for cu->dies to be nullptr in follow_die_offset. It might be a
leftover from the psymtab days.
In most cases, we see that the dwarf2_cu passedas `*ref_cu` has been
obtained by doing:
per_objfile->get_cu (per_cu);
The only way for a dwarf2_cu to end up in the per_objfile like this is
through load_full_comp_unit or read_signatured_type. Both of these
functions call `reader.read_all_dies ()` (which loads the DIEs in memory
and assigns dwarf2_cu::dies) before transferring the newly created
dwarf2_cu to the per_objfile. So any dwarf2_cu obtained through
per_objfile->get_cu (per_cu)
... will have its DIEs set.
The only case today I'm aware of of a dwarf2_cu without DIEs is in the
cooked indexer. It creates a cutu_reader, but does not call
read_all_dies. Instead, it gets the info_ptr from the cutu_reader and
reads the DIEs from the section buffer directly, on its own. But this
is an entirely different code path that doesn't assign dwarf2_cu
objects to per_objfile.
So, remove the code path in follow_die_offset that tests for
`source_cu->dies == NULL`. I added an assert at the top of the function
to verify that `source_cu->dies` is always non-nullptr, as a way to
test my hypothesis. We could probably get rid of it, but I left it
there because it doesn't cost much to have it.
Change-Id: I97f269f092128800850aa5e64eda7032c2edec60 Approved-By: Tom Tromey <tom@tromey.com>
This is a bit subjective, but I often struggle to understand what
cutu_reader::keep is meant to do (keep what, where). Perhaps it's just
a question of bad naming, but I think it's a bit confusing for
cutu_reader to transfer the ownership of the dwarf2_cu to the
per_objfile directly.
Add the cutu::release_cu method and make the caller of cutu_reader
transfer the ownership to the per_objfile object.
Right now, it is theoretically possible for release_cu to return
nullptr, so I made callers check the return value. A patch later in
this series will change release_cu to ensure it always return
non-nullptr, so those callers will get simplified.
Change-Id: I3103ff894d1654a95c9d69001073c218501c988a Approved-By: Tom Tromey <tom@tromey.com>
I don't really like this poking into cutu_reader's data structures from
the outside, I would prefer if that work was done by cutu_reader.
Rename the read_die_and_siblings method to read_all_dies, and do that
work inside cutu_reader.
I also moved these operations inside the read_all_dies method:
The rationale for this is that read_all_dies (and the functions it
calls) is responsible for filling the die_hash set. So I think it makes
sense for it to do the reserve.
It is also cutu_reader's job, currently, to create and fill the fields
of dwarf2_cu. So I think it makes sense for it to set cu->dies, after
having read the DIEs in memory.
Change-Id: I088c2e0b367db7d1f67e8c9e2d5b0d61165292fc Approved-By: Tom Tromey <tom@tromey.com>
Simon Marchi [Fri, 14 Mar 2025 04:32:47 +0000 (00:32 -0400)]
gdb/dwarf: access m_info_ptr directly instead of passing info_ptr around
The few methods of cutu_reader that read DIEs into memory generally
receive an info_ptr that says where to start reading and return another
one (either by return value or parameter) indicating where the caller
should continue reading.
We can avoid all this passing around by having these methods access
m_info_ptr directly. This allows changing some methods that read DIEs
to return `die_info *`, instead of returning it by parameter, which just
makes the code simpler to read, I think.
The only method that meaningfully reads and writes m_info_ptr (except
the places that initially set it up) is read_full_die_1. It reads and
increments m_info_ptr once to read the abbrev and once again to read
each attribute. Other methods use it for logging.
The methods cutu_reader::read_attribute and
cutu_reader::read_attribute_value do not touch m_info_ptr directly,
because they are used in cooked-indexer.c, which appears to read some
things in a non-linear fashion, unlike cutu_reader's DIE-reading
methods. The cooked indexer calls cutu_reader::info_ptr to get the
m_info_ptr value just after the top-level DIE, and then it does its own
attribute reading after that.
Change-Id: I251f63d13d453a2827b21349760da033171880e2 Approved-By: Tom Tromey <tom@tromey.com>
projects / thirdparty / binutils-gdb.git / log
