This converts the target fileio BFD iovec implementation to use the
new type-safe gdb_bfd_openr_iovec.
Reviewed-By: Lancelot Six <lancelot.six@amd.com>
This patch adds a new, type-safe variant of gdb_bfd_openr_iovec. In
this approach, the underlying user data is simply an object, the
callbacks are methods, and the "open" function is a function view.
Nothing uses this new code yet.
Reviewed-By: Lancelot Six <lancelot.six@amd.com>
This commit fixes an issue that was discovered while writing the tests
for the previous commit.
I noticed that, when GDB restarts an inferior, the executable_changed
event would trigger twice. The first notification would originate
from:
#0 exec_file_attach (filename=0x4046680 "/tmp/hello.x", from_tty=0) at ../../src/gdb/exec.c:513
#1 0x00000000006f3adb in reopen_exec_file () at ../../src/gdb/corefile.c:122
#2 0x0000000000e6a3f2 in generic_mourn_inferior () at ../../src/gdb/target.c:3682
#3 0x0000000000995121 in inf_child_target::mourn_inferior (this=0x2fe95c0 <the_amd64_linux_nat_target>) at ../../src/gdb/inf-child.c:192
#4 0x0000000000995cff in inf_ptrace_target::mourn_inferior (this=0x2fe95c0 <the_amd64_linux_nat_target>) at ../../src/gdb/inf-ptrace.c:125
#5 0x0000000000a32472 in linux_nat_target::mourn_inferior (this=0x2fe95c0 <the_amd64_linux_nat_target>) at ../../src/gdb/linux-nat.c:3609
#6 0x0000000000e68a40 in target_mourn_inferior (ptid=...) at ../../src/gdb/target.c:2761
#7 0x0000000000a323ec in linux_nat_target::kill (this=0x2fe95c0 <the_amd64_linux_nat_target>) at ../../src/gdb/linux-nat.c:3593
#8 0x0000000000e64d1c in target_kill () at ../../src/gdb/target.c:924
#9 0x00000000009a19bc in kill_if_already_running (from_tty=1) at ../../src/gdb/infcmd.c:328
#10 0x00000000009a1a6f in run_command_1 (args=0x0, from_tty=1, run_how=RUN_STOP_AT_MAIN) at ../../src/gdb/infcmd.c:381
#11 0x00000000009a20a5 in start_command (args=0x0, from_tty=1) at ../../src/gdb/infcmd.c:527
#12 0x000000000068dc5d in do_simple_func (args=0x0, from_tty=1, c=0x35c7200) at ../../src/gdb/cli/cli-decode.c:95
While the second originates from:
#0 exec_file_attach (filename=0x3d7a1d0 "/tmp/hello.x", from_tty=0) at ../../src/gdb/exec.c:513
#1 0x0000000000dfe525 in reread_symbols (from_tty=1) at ../../src/gdb/symfile.c:2517
#2 0x00000000009a1a98 in run_command_1 (args=0x0, from_tty=1, run_how=RUN_STOP_AT_MAIN) at ../../src/gdb/infcmd.c:398
#3 0x00000000009a20a5 in start_command (args=0x0, from_tty=1) at ../../src/gdb/infcmd.c:527
#4 0x000000000068dc5d in do_simple_func (args=0x0, from_tty=1, c=0x35c7200) at ../../src/gdb/cli/cli-decode.c:95
In the first case the call to exec_file_attach first passes through
reopen_exec_file. The reopen_exec_file performs a modification time
check on the executable file, and only calls exec_file_attach if the
executable has changed on disk since it was last loaded.
However, in the second case things work a little differently. In this
case GDB is really trying to reread the debug symbol. As such, we
iterate over the objfiles list, and for each of those we check the
modification time, if the file on disk has changed then we reload the
debug symbols from that file.
However, there is an additional check, if the objfile has the same
name as the executable then we will call exec_file_attach, but we do
so without checking the cached modification time that indicates when
the executable was last reloaded, as a result, we reload the
executable twice.
In this commit I propose that reread_symbols be changed to
unconditionally call reopen_exec_file before performing the objfile
iteration. This will ensure that, if the executable has changed, then
the executable will be reloaded, however, if the executable has
already been recently reloaded, we will not reload it for a second
time.
After handling the executable, GDB can then iterate over the objfiles
list and reload them in the normal way.
With this done I now see the executable reloaded only once when GDB
restarts an inferior, which means I can remove the kfail that I added
to the gdb.python/py-exec-file.exp test in the previous commit.
Approved-By: Tom Tromey <tom@tromey.com>
This commit makes the executable_changed observable available through
the Python API as an event. There's nothing particularly interesting
going on here, it just follows the same pattern as many of the other
Python events we support.
The new event registry is called events.executable_changed, and this
emits an ExecutableChangedEvent object which has two attributes, a
gdb.Progspace called 'progspace', this is the program space in which
the executable changed, and a Boolean called 'reload', which is True
if the same executable changed on disk and has been reloaded, or is
False when a new executable has been loaded.
One interesting thing did come up during testing though, you'll notice
the test contains a setup_kfail call. During testing I observed that
the executable_changed event would trigger twice when GDB restarted an
inferior. However, the ExecutableChangedEvent object is identical for
both calls, so the wrong information is never sent out, we just see
one too many events.
I tracked this down to how the reload_symbols function (symfile.c)
takes care to also reload the executable, however, I've split fixing
this into a separate commit, so see the next commit for details.
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
Approved-By: Tom Tromey <tom@tromey.com>
This commit continues the work of the previous few commits.
My goal is to expose the executable_changed observer through the
Python API as an event.
At this point adding executable_changed as an event to the Python API
is trivial, but before I do that I would like to add some additional
arguments to the observable, which currently has no arguments at all.
The new arguments I wish to add are:
1. The program_space in which the executable was changed, and
2. A boolean flag that will indicate if the executable changed to a
whole new path, or if GDB just spotted that the executable changed on
disk (e.g. the user recompiled the executable).
In this commit I change the signature of the observable and then pass
the arguments through at the one place where this observable is
notified.
As there are (currently) no users of this observable nothing else
needs updating. In the next commit I'll add a listener for this
observable in the Python code, and expose this as an event in the
Python API.
Additionally, with this change, it should be possible to update the
insight debugger to make use of this observable rather than using the
deprecated_exec_file_display_hook (as it currently does), which will
then allow this hook to be removed from GDB.
There should be no user visible changes after this commit.
Approved-By: Tom Tromey <tom@tromey.com>
This commit continues the work of the previous two commits.
My goal, in the next couple of commits, is to expose the
executable_changed observable in the Python API as an event. However,
before I do that I want to remove the use of the executable_changed
observable from the reread_symbols function in symfile.c as this use
isn't directly associated with a change of the executable file, and so
seems wrong.
In the previous two commits I have removed all users of the
executable_changed observer as I believe those users can, and should,
actually be listening for the new_objfile observable instead, so now
there are no users of the executable_changed observable.
As such, I think removing the use of executable_changed from the
function reread_symbols is perfectly safe, and correct. At this point
the executable has not been changed, so we shouldn't be sending an
executable_changed notification, and, as there is nobody listening to
this observable, we can't break anything by removing this call.
There should be no user visible changes after this commit.
Approved-By: Tom Tromey <tom@tromey.com>
This commit continues with the task started in the previous commit,
and is similar in many ways.
The goal of the next couple of commits is to expose the
executable_changed observable in the Python API as an event. Before I
do this I would like to remove the additional call to the
executable_changed observable which can be found in the reread_symbols
function in the symfile.c file, as I don't believe that this use
actually corresponds to a change in the current executable.
The previous commit removed one user of the executable_changed
observable and replaced it with a new_obfile observer instead, and
this commit does the same thing.
In auxv.c we use the executable_changed observable to call
invalidate_auxv_cache, which then calls:
invalidate_auxv_cache_inf (current_inferior ());
The auxv cache is already (additionally) cleared when an inferior
exits and when an inferior appears.
As with the previous commit, I think we can safely replace the use of
the executable_changed observable with a use of the new_obfile
observable. All the tests still pass, and with some locally placed
printf calls, I think that the cache is still being cleared in all the
cases that should matter.
Approved-By: Tom Tromey <tom@tromey.com>
My goal for the next few commits is to expose the executable_changed
observable from the Python API.
However, there is call to the executable_changed observable in the
reread_symbols function (in symfile.c), and this doesn't actually
correspond to the executable changing. My idea then, is to remove
this use of the executable_changed observable, but, before I can do
that, I need to check that nothing is going to break, and that
requires my to think about the current users of this observable.
One current user of executable_changed is in symtab.c. We add an
executable_changed observer that calls:
set_main_name (nullptr, language_unknown);
to discard all information about the main function when the executable
changes.
However, changing the executable doesn't actually change the debug
information. The debug information changes when the symbol-file
changes, so I think this observer is in slightly the wrong place.
The new_objfile observable is (unfortunately) overloaded, it is called
when a new objfile is loaded, and also (when its argument is nullptr),
when all debug information should be discarded.
It turns out that there is already a new_objfile observer in
symtab.c. I propose that, when the argument is nullptr (indicating
all debug info should be discarded), that we should call set_main_name
to discard the information about the main function. We can then
remove the executable_changed observer from symtab.c.
All tests still pass, and, in my local world, I added some debug
printf calls, and I think we are still discarded the main information
everywhere we need to.
Approved-By: Tom Tromey <tom@tromey.com>
Add a new Progspace.executable_filename attribute that contains the
path to the executable for this program space, or None if no
executable is set.
The path within this attribute will be set by the "exec-file" and/or
"file" commands.
Accessing this attribute for an invalid program space will raise an
exception.
This new attribute is similar too, but not the same as the existing
gdb.Progspace.filename attribute. If I could change the past, I'd
change the 'filename' attribute to 'symbol_filename', which is what it
actually represents. The old attribute will be set by the
'symbol-file' command, while the new attribute is set by the
'exec-file' command. Obviously the 'file' command sets both of these
attributes.
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
Approved-By: Tom Tromey <tom@tromey.com>
Add a new Progspace.symbol_file attribute. This attribute holds the
gdb.Objfile object that corresponds to Progspace.filename, or None if
there is no main symbol file currently set.
Currently, to get this gdb.Objfile, a user would need to use
Progspace.objfiles, and then search for the objfile with a name that
matches Progspace.filename -- which should work just fine, but having
direct access seems a little nicer.
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
Approved-By: Tom Tromey <tom@tromey.com>
Extend the description for Progspace.filename in the documentation to
mention what the returned string is actually the filename
for (e.g. that it is the filename passed to the 'symbol-file' or
'file' command).
Also document that this attribute will be None if no symbol file is
currently loaded.
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
Approved-By: Tom Tromey <tom@tromey.com>
Since commit b42405a159 ("gdb: Update x86 Linux architectures to
support XSAVE layouts."), the test gdb.base/gcore.exp fails on my AMD
Ryzen 3700X machine:
FAIL: gdb.base/gcore.exp: corefile restored all registers
The test gets the register state (saves the output of "info
all-registers"), saves a core with the "gcore" command, loads the core,
and checks the register state against the one previously saved. The
problem is that when reading registers from the core file, the last half
of ymm registers is unavailable:
(gdb) print $ymm0.v32_int8
$1 = {0, -77, -23, -9, -1, 127, 0, 0, 0, -77, -23, -9, -1, 127, 0, 0, <unavailable> <repeats 16 times>}
One strange thing with this machine is that the bitset of state
components supported by XCR0 is 0x207, meaning "x87 | SSE | AVX | PKRU",
but XCR0 at runtime is 0x7, meaning "x87 | SSE | AVX". So, PKRU appears
to be supported by the processor, but disabled by the kernel. I didn't
find why yet.
From CPUID leaf EAX=0Dh, ECX=00h, GDB can get:
- from EBX: max size of the XSAVE area required by features currently
enabled in XCR0. On my machine, it's 0x340 (832).
- from ECX: max size of the XSAVE area required by all features
supported by XCR0. On my machine, it's 0x380 (896).
At runtime, GDB uses ECX (max size required by all supported features)
to fill the x86_xsave_layout::sizeof_xsave. So, when writing the core
file note for the XSAVE state, it writes a note of size 896, even though
it doesn't write the PKRU state. When loading back the core, GDB tries
to figure out the layout of the XSAVE area based on what features are
enabled in XCR0 and the size of the note (the size of the XSAVE area).
Since my combination of XCR0 and size of XSAVE area doesn't match any
combination known by GDB, GDB falls back to a gdbarch supporting only
x87 and SSE.
This patch changes GDB to populate the x86_xsave_layout::sizeof_xsave
field (and consequently the size of the XSAVE state note in core files)
using EBX, the size of the XSAVE area required by currently enabled
features in XCR0. This makes i387_guess_xsave_layout recognize my case
with this condition:
else if (HAS_AVX (xcr0) && xsave_size == 832)
{
/* Intel and AMD CPUs supporting AVX. */
layout.avx_offset = 576;
}
In other words, just as if my machine didn't support PKRU at all.
Another reason why I think this change makes sense is that XSAVE state
notes in kernel-generated cores on this machine have size 832. So this
change makes GDB-generated cores more similar to kernel-generated ones,
reducing the diversity of XSAVE state notes that GDB needs to be able to
figure out.
Note that if PKRU was enabled on my machine, then the effective XSAVE
area size would be 896 bytes. We would need to add a case in
i387_guess_xsave_layout for that combination, since there is no
currently. But I don't have a way to test that right now, since I don't
know why PKRU is disabled.
Relevant review note from John Baldwin:
One further note is that the Linux x86 arches use x86_xsave_length()
to infer ("guess") the size of the XSAVE register set that the Linux
kernel writes out in core dumps. On FreeBSD x86 arches, GDB is able
to query this size directly from the kernel via ptrace. My use of ECX
for this guess earlier was just not the best guess. In the case that
the kernel enables all of the available features, then ECX and EBX
have the same values, so this only matters for a system where the
kernel has enabled a subset of available XSAVE extensions.
Change-Id: If64f30307f3a2e5ca3e1fd1cb7379ea840805a85
Reviewed-By: John Baldwin <jhb@FreeBSD.org>
PR 30886 * elf-bfd.h (struct elf_obj_tdata): Add dt_strsz field.
* elf.c (_bfd_elf_get_dynamic_symbols): Add a NUL byte at the end of the string table. Initialise the dt_strsz field. (_bfd_elf_slurp_version_tables): Only free the contents if they were malloc'ed. Add checks before setting string pointers in the dt_strtab buffer.
When running test-case gdb.base/unwind-on-each-insn-amd64-2.exp with target
board unix/-fPIE/-pie, I run into:
...
gdb compile failed, ld: unwind-on-each-insn-amd64-21.o: relocation \
R_X86_64_32S against `.text' can not be used when making a PIE object; \
recompile with -fPIE
ld: failed to set dynamic section sizes: bad value
...
Fix this by hardcoding nopie in the test-case, and for good measure in the
other test-cases that source unwind-on-each-insn.exp.tcl and use a .s file.
Tested on x86_64-linux.
Approved-by: Kevin Buettner <kevinb@redhat.com>
Add check for libdebuginfod 0.188 in AC_DEBUGINFOD and if found
define macro HAVE_LIBDEBUGINFOD_FIND_SECTION.
This macro indicates support for downloading ELF sections from
debuginfod servers.
AVX-* features / insns paralleling earlier introduced AVX512* ones can
be encoded more compactly when the respective feature was explicitly
enabled by the user.
Apparently from its introduction the variable was only ever written (the
only read is merely to determine whether to write it with another value).
(Since, due to the need to re-indent, the adjacent lines setting
cpu_arch_tune need touching anyway, switch to using PREOCESSOR_*
constants where applicable, to make more obvious what the resulting
state is going to be.)
These may not be set from a value derived from cpu_arch_flags: That
starts with (almost) all functionality enabled, while cpu_arch_isa_flags
is supposed to track features that were explicitly enabled (and perhaps
later disabled) by the user.
To avoid needing to do any such adjustment in two places (each),
introduce helper functions used by both command line handling and
directive processing.
The Cygwin runtime spawns a few extra threads, so using hardcoded
thread numbers in tests rarely works correctly. Thankfully, this
testcase already records the ids of the important threads in globals.
It just so happens that they are not used in a few tests. This commit
fixes that.
With this, the test passes cleanly on Cygwin [1]. Still passes cleanly on
x86-64 GNU/Linux.
[1] - with system GDB. Upstream GDB is missing a couple patches
Cygwin carries downstream.
Approved-By: Tom Tromey <tom@tromey.com>
Change-Id: I01bf71fcb44ceddea8bd16b933b10b964749a6af
On Cygwin, I see:
(gdb) PASS: gdb.threads/pthreads.exp: break thread1
continue
Continuing.
pthread_attr_setscope 1: Not supported (134)
[Thread 3732.0x265c exited with code 1]
[Thread 3732.0x2834 exited with code 1]
[Thread 3732.0x2690 exited with code 1]
Program terminated with signal SIGHUP, Hangup.
The program no longer exists.
(gdb) FAIL: gdb.threads/pthreads.exp: Continue to creation of first thread
... and then a set of cascading failures.
Fix this by treating ENOTSUP the same way as if PTHREAD_SCOPE_SYSTEM
were not defined. I.e., ignore ENOTSUP errors, and proceed with
testing.
Approved-By: Tom Tromey <tom@tromey.com>
Change-Id: Iea68ff8b9937570726154f36610c48ef96101871
On Cygwin, I noticed:
(gdb) PASS: gdb.threads/pthreads.exp: break thread1
continue
Continuing.
pthread_attr_setscope 1: No error
[Thread 8732.0x28f8 exited with code 1]
[Thread 8732.0xb50 exited with code 1]
[Thread 8732.0x17f8 exited with code 1]
Program terminated with signal SIGHUP, Hangup.
The program no longer exists.
(gdb) FAIL: gdb.threads/pthreads.exp: Continue to creation of first thread
Note "No error" in "pthread_attr_setscope 1: No error". That is a bug
in the test. It is using perror, but that prints errno, while the
pthread functions return the error directly. Fix all cases of the
same problem, by adding a new print_error function and using it.
We now get:
...
pthread_attr_setscope 1: Not supported (134)
...
Approved-By: Tom Tromey <tom@tromey.com>
Change-Id: I972ebc931b157bc0f9084e6ecd8916a5e39238f5
gdb.threads/pthreads.c is declaring functions with old K&R style.
This commit converts them to ANSI style.
Approved-By: Tom Tromey <tom@tromey.com>
Change-Id: I1ce007c67bb4ab1e49248c014c7881e46634f8f8
Following the folding of some generic AVX/AVX2 templates with their
AVX512F counterpart ones, do this for FMA ones as well, requiring one
further adjustment to cpu_flags_match().
In anticipation of APX introduce logic to reduce the number of templates
we have now, allowing to limit some the number of ones we then need to
gain.
The fundamental requirements are that
- attributes be compatible, which specifically means VexW needs to be
the same in the templates (which often isn't the case, for VEX
encodings having far more WIG tha, EVEX ones),
- the EVEX form being AVX512F (with or without AVX512VL), not any of its
extensions (the same will then be required for APX - it'll need to be
APX_F).
Note that in check_register() there's now a redundant zmm check. Since
this logic will need revisiting for APX anyway, I'd like to keep it that
way for now. (Similarly a couple of if()-s which could be folded are
kept separate, to reduce code churn when adding APX support.)
SAE / embedded rounding are invalid when there's the memory operand, as
the bit encoding this specifies broadcast in that case.
Broadcast needs to be specified on the memory operand.
PR gas/30856
In 5cc007751c ("x86: further adjust extend-to-32bit-address
conditions") I neglected the case of PUSH, which is the only insn
allowing (proper) symbol addresses to be used as immediates (not
displacements, like CALL/JMP) in the absence of any register operands.
Since it defaults to 64-bit operand size, guessing an L suffix is wrong
there.
With byacc, we get an ODR warning with YYSTACKDATA between ada-exp.c.tmp
and c-exp.c.tmp. Just include it in the list of symbols we rename.
PR gdb/30839
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30839
Approved-By: Tom de Vries <tdevries@suse.de>
Copyright-paperwork-exempt: yes
Add a macro pcaddi instruction to support "pcaddi rd, symbol".
pcaddi has a 20-bit signed immediate, it can address a +/- 2MB pc relative
address, and the address should be 4-byte aligned.
Bug 29965 shows on a Linux kernel >= 6.1, that test fails consistently
with:
FAIL: gdb.threads/process-exit-status-is-leader-exit-status.exp: iteration=0: continue (the program exited)
...
FAIL: gdb.threads/process-exit-status-is-leader-exit-status.exp: iteration=9: continue (the program exited)
This is due to a change in Linux kernel behavior [1] that affects
exactly what this test tests. That is, if multiple threads (including
the leader) call SYS_exit, the exit status of the process should be the
exit status of the leader. After that change in the kernel, it is no
longer the case.
Add an xfail in the test, based on the Linux kernel version. The goal
is that if a regression is introduced in GDB regarding this feature, it
should be caught if running on an older kernel where the behavior was
consistent.
[1] https://bugzilla.suse.com/show_bug.cgi?id=1206926
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29965
Change-Id: If6ab7171c92bfc1a3b961c7179e26611773969eb
Approved-By: Tom de Vries <tdevries@suse.de>
When running test-case gdb.ada/mi_task_arg.exp on openSUSE Tumbleweed using
gcc 13.2.1, I run into (layout adapted for readability):
...
-stack-list-arguments 1^M
^done,stack-args=[
frame={level="0",args=[]},
frame={level="1",args=[{name="<_task>",value="0x464820"},
{name="<_taskL>",value="129"}]},
frame={level="2",args=[{name="self_id",value="0x464840"}]},
frame={level="3",args=[]},
frame={level="4",args=[]}
]^M
(gdb) ^M
FAIL: gdb.ada/mi_task_arg.exp: -stack-list-arguments 1 (unexpected output)
...
On openSUSE Leap 15.4 with gcc 7.5.0 I get instead:
...
-stack-list-arguments 1^M
^done,stack-args=[
frame={level="0",args=[]},
frame={level="1",args=[{name="<_task>",value="0x444830"}]},
frame={level="2",args=[{name="self_id",value="0x444850"}]},
frame={level="3",args=[]},
frame={level="4",args=[]}]^M
(gdb) ^M
PASS: gdb.ada/mi_task_arg.exp: -stack-list-arguments 1
...
The difference in gdb output is due to difference in the dwarf generated by
the compiler, so I don't see a problem with gdb here.
Fix this by updating the test-case to accept this output.
Tested on x86_64-linux.
Approved-By: Tom Tromey <tom@tromey.com>
printing.py references "gdb.printing" in a few spots, but there's no
need for this. I think this is leftover from when this code was
(briefly) in some other module. This patch removes the unnecessary
qualifications. Tested on x86-64 Fedora 36.
This adds two new pretty-printer methods, to support random access to
children. The methods are implemented for the no-op array printer,
and DAP is updated to use this.
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
There was an earlier thread about adding new methods to
pretty-printers:
https://sourceware.org/pipermail/gdb-patches/2023-June/200503.html
We've known about the need for printer extensibility for a while, but
have been hampered by backward-compatibilty concerns: gdb never
documented that printers might acquire new methods, and so existing
printers may have attribute name clashes.
To solve this problem, this patch adds a new pretty-printer tag class
that signals to gdb that the printer follows new extensibility rules.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30816
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
When running the gdb testsuite inside a container, I run into:
...
(gdb) gdb_expect_list pattern: /1 +root +[/a-z]*(init|systemd)/
FAIL: gdb.server/ext-run.exp: get process list (pattern 2)
...
because there's no process with pid 1 and cmd init or systemd.
In the host system (where the test passes), I have:
...
$ ps -f 1
UID PID PPID C STIME TTY STAT TIME CMD
root 1 0 0 Sep25 ? Ss 0:03 /usr/lib/systemd/systemd ...
...
but in the container instead:
...
UID PID PPID C STIME TTY STAT TIME CMD
root 1 0 0 11:45 pts/0 Ss 0:00 /bin/bash
...
Fix this by also accepting bash as a valid cmd.
Tested on x86_64-linux.
Approved-By: Tom Tromey <tom@tromey.com>
Following on from the previous patch to make the feature macros take
a word number, this one increases the number of flag words from 1 to 2.
The patch uses some dummy features to push the number of features
over 64. The intention is that these should be reused by real
features rather than kept as-is.
The AArch64 feature-flag code is currently limited to a maximum
of 64 features. This patch reworks it so that the limit can be
increased more easily. The basic idea is:
(1) Turn the ARM_FEATURE_FOO macros into an enum, with the enum
counting bit positions.
(2) Make the feature-list macros take an array index argument
(currently always 0). The macros then return the
aarch64_feature_set contents for that array index.
An N-element array would then be initialised as:
{ MACRO (0), ..., MACRO (N - 1) }
(3) Provide convenience macros for initialising an
aarch64_feature_set for:
- a single feature
- a list of individual features
- an architecture version
- an architecture version + a list of additional features
(2) and (3) use the preprocessor to generate static initialisers.
The main restriction was that uses of the same preprocessor macro
cannot be nested. So if a macro wants to do something for N individual
arguments, it needs to use a chain of N macros to do it. There then
needs to be a way of deriving N, as a preprocessor token suitable for
pasting.
The easiest way of doing that was to precede each list of features
by the number of features in the list. So an aarch64_feature_set
initialiser for three features A, B and C would be written:
AARCH64_FEATURES (3, A, B, C)
This scheme makes it difficult to keep AARCH64_FEATURE_CRYPTO as a
synonym for SHA2+AES, so the patch expands the former to the latter.
With any gdb.dap test and python 3.6 I run into:
...
Error occurred in Python: 'code' object has no attribute 'co_posonlyargcount'
ERROR: eof reading json header
...
The attribute is not supported before python 3.8, which introduced the
"Positional−only Parameters" concept.
Fix this by using try/except AttributeError.
Tested on x86_64-linux:
- openSUSE Leap 15.4 with python 3.6, and
- openSUSE Tumbleweed with python 3.11.5.
Approved-By: Tom Tromey <tom@tromey.com>
