We currently generate some validation code within the gdbarch getter
methods.

This commit adjusts the algorithm used to generate this validation
slightly to make the gdbarch.py code (I think) clearer; there's no
significant changes to what is generated.

The validation algorithm for gdbarch values is now:

  - If the Value has an 'invalid' field that is a string, use that for
    validation,

  - If the Value has its 'predicate' field set to true, then check the
    predicate returns true, this ensures the predicate has been
    called,

  - If the Value has its 'invalid' field set to True, or the Value has
    'postdefault' field, then check the fields has changed from its
    initial value,

  - Otherwise no validation is performed.

The only changes after this commit are:

  - Some comments change slightly, and

  - For 'gcore_bfd_target' and 'max_insn_length' we now validate by
    calling the predicate rather than checking the field value
    directly, the underlying check being performed is unchanged
    though.

There should be no user visible changes after this commit.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

For some reason the following value components of gdbarch:

  bfloat16_format
  half_format
  float_format
  double_format
  long_double_format
  so_ops

All use a postdefault but no predefault to set the default value for
the component.

As the postdefault values for these components are all constant
pointers that don't depend on other fields within the gdbarch, then I
don't see any reason why we couldn't use a predefault instead.

So lets do that.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

This commit ensures that the 'invalid' property of all components is
either True, False, or a string.

Additionally, this commit allows a component to have both a predicate
and for the 'invalid' property to be a string.

Removing the option for 'invalid' to be None allows us to simplify the
algorithms in gdbarch.py a little.

Allowing a component to have both a predicate and an 'invalid' string
means that we can validate the value that a tdep sets into a field,
but also allow a predicate to ensure that the field has changed from
the default.

This functionality isn't going to be used in this series, but I have
tested it locally and believe that it would work, and this might make
it easier for others to add new components in the future.

In gdbarch_types.py, I've updated the type annotations to show that
the 'invalid' field should not be None, and I've changed the default
for this field from None to False.

The change to using False as the default is temporary.  Later in this
series I'm going to change the default to True, but we need more fixes
before that can be done.

Additionally, in gdbarch_types.py I've removed an assert from
Component.get_predicate.  This assert ensured that we didn't have the
predicate field set to True and the invalid field set to a string.
However, no component currently uses this configuration, and after
this commit, that combination is now supported, so the assert can be
removed.

As a consequence of the gdbarch_types.py changes we see some
additional comments generated in gdbarch.c about verification being
skipped due to the invalid field being False.  This comment is inline
with plenty of other getters that also have a similar comment.  Plenty
of the getters do have validation, so I think it is reasonable to have
a comment noting that the validation has been skipped for a specific
reason, rather than due to some bug.

In gdbarch_components.py I've had to add 'invalid=True' for two
components: gcore_bfd_target and max_insn_length, without this the
validation in the gdbarch getter would disappear.

And in gdbarch.py I've reworked the logic for generating the
verify_gdbarch function, and for generating the getter functions.

The logic for generating the getter functions is still not ideal,  I
ended up having to add this additional logic block:

  elif c.postdefault is not None and c.predefault is not None:
      print("  /* Check variable changed from pre-default.  */", file=f)
      print(f"  gdb_assert (gdbarch->{c.name} != {c.predefault});", file=f)

which was needed to ensure we continued to generate the same code as
before, without this the fact that invalid is now False when it would
previously have been None, meant that we dropped the gdb_assert in
favour of a comment like:

  print(f"  /* Skip verify of {c.name}, invalid_p == 0 */", file=f)

which is clearly not a good change.  We could potentially look at
improving this in a later commit, but I don't plan to do that in this
series.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Restructure how gdbarch.py generates the verify_gdbarch function.
Previously the postdefault handling was bundled together with the
validation.  This means that a field can't have both a postdefault,
and set its invalid attribute to a string.

This doesn't seem reasonable to me, I see no reason why a field can't
have both a postdefault (used when the tdep doesn't set the field),
and an invalid expression, which can be used to validate the value
that a tdep might set.

In this commit I restructure the verify_gdbarch generation code to
allow the above, there is no change in the actual generated code in
this commit, that will come in later commit.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Following on from the previous commit, this commit removes yet more
'invalid=True' lines from gdbarch_components.py where the invalid
setting has no effect.

Due to the algorithm used in gdbarch.py for generated verify_gdbarch,
if a component has a postdefault value then no invalid check will ever
be generated for the component, as such setting 'invalid=True' on the
component is pointless.  This commit removes the setting of invalid.

There is no change in the generated code after this commit.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Due to the algorithm used to generate verify_gdbarch in gdbarch.py, if
a component has a predicate, then a validation check will never be
generated.

There are a bunch of components that are declared with both a
predicate AND have 'invalid=True' set.  The 'invalid=True' has no
effect.

In this commit I clean things up by removing all these additional
'invalid=True' lines.  There's no change in any of the generated files
after this commit.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

gdb 13.1 crashes while running the rust compiler's debugger tests.
The crash has a number of causes.

First, the rust compiler still uses the C++-like _Z mangling, but with
its own twist -- some hex digits added to the end of a symbol.  So,
while gdb finds the correct name of "main":

(top-gdb) p name
$13 = 0x292e0c0 "rustc_gdb_1031745::main"

It isn't found in the minsyms, because C++ demangling yields:

[99] t 0x90c0 _ZN17rustc_gdb_10317454main17h5b5be7fe16a97225E section .text  rustc_gdb_1031745::main::h5b5be7fe16a97225  zko06yobckx336v

This could perhaps be fixed.  I also filed a new PR to suggest
preferring the linkage name of the main program.

Next, the rust compiler emits both a DW_TAG_subprogram and a
DW_TAG_namespace for "main".  This happens because the file is named
"main.rs" -- i.e., the bug is specific to the source file name.  The
crash also seems to require the nested function inside of 'main', at
least for me.  The namespace always is generated, but perhaps this
changes the ordering in the DWARF.

When inside_main_func looks up the main symbol, it finds the namespace
symbol rather than the function.  (I filed a bug about fixing gdb's
symbol tables -- long overdue.)

Meanwhile, as I think it's important to fix this crash sooner rather
than later, this patch changes inside_main_func to check that the
symbol that is found is LOC_BLOCK.  This perhaps should have been done
in the first place, anyway.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30158

When running gdb.python/tui-window.exp with host board
local-remote-host-notty and target board native-gdbserver, I get:
...
FAIL: gdb.python/tui-window-factory.exp: msg_2: \
  check test_window box (box check: ul corner is l, not +)
...

The problem is that the result of Term::prepare_for_tui is not checked.

Fix this by adding the missing check.

Tested on x86_64-linux.

When running gdb.python/tui-window.exp with host board
local-remote-host-notty and target board native-gdbserver, I get:
...
UNSUPPORTED: gdb.python/tui-window.exp: TUI not supported
FAIL: gdb.python/tui-window.exp: test title
...

Fix this by adding the missing return after the unsupported.

Tested on x86_64-linux.

When running test-case gdb.tui/completion.exp with host board
local-remote-host-notty and target board native-gdbserver, I get:
...
FAIL: gdb.tui/completion.exp: completion of layout names: \
  tab completion (timeout)
...

The test-case contains a few tests that do tab completion, which requires
readline, which is unavailable with host board local-remote-host-notty.

Fix this by adding the missing check for readline_is_used.

Tested on x86_64-linux.

When running test-case gdb.tui/tui-layout.exp with host board
local-remote-host-notty and target board native-gdbserver, I get:
...
FAIL: gdb.tui/tui-layout.exp: terminal=dumb: execution=false: layout=asm: \
  layout asm (timeout)
...

The problem is that the test-case expects that the default "setenv TERM dumb"
has effect, which is not the case for remote host.

Fix this by skipping the test for remote host.

Tested on x86_64-linux.

When running test-case gdb.tui/tui-nl-filtered-output.exp with host board
local-remote-host-notty and target board native-gdbserver, I get:
...
FAIL: gdb.tui/tui-nl-filtered-output.exp: check printf output
...

The problem is that Term::enter_tui is returning 0, but the test-case doesn't
check for this, and consequently runs unsupported tests.

Fix this by adding the missing check.

Tested on x86_64-linux.

When running test-case gdb.tui/corefile-run.exp with both host and target board
local-remote-host-native.exp, we run into:
...
FAIL: gdb.tui/corefile-run.exp: load corefile
...
while this passes with USE_TUI=0.

The problem is that the TUI setup code uses "setenv TERM ansi", which has no
effect on remote host.

I can confirm this analysis by working around this problem in
local-remote-host-native.exp like this:
...
-    spawn $RSH -t -l $username $remote $cmd
+    spawn $RSH -t -l $username $remote "export TERM=ansi; $cmd"
...

For now, simply make TUI unsupported for remote host, by returning 0 in
prepare_for_tui.

Tested on x86_64-linux.

Once in a while I find myself rewriting a TUI test-case into a non-TUI
test-case, to better understand whether the problem I'm looking at is
related to the TUI or not.

I've got the impression that I've done this sufficiently often that it's worth
committing the non-TUI version, so having just written a non-TUI version of
gdb.tui/corefile-run.exp, let's commit it.

The non-TUI version can be enabled by doing:
...
$ make check "RUNTESTFLAGS=gdb.tui/corefile-run.exp USE_TUI=0"
...

Also remove hard-coding of a source line number.

Tested on x86_64-linux.

In test-case gdb.tui/corefile-run.exp, we have this bit:
...
require !use_gdb_stub
if { [target_info gdb_protocol] == "extended-remote" } {
    untested "not supported"
    return
}
...

So with target board native-gdbserver we get:
...
UNSUPPORTED: gdb.tui/corefile-run.exp: require failed: !use_gdb_stub
...
and with target board native-extended-gdbserver instead:
...
UNTESTED: gdb.tui/corefile-run.exp: not supported
...

Fix this by:
- adding an optional argument target_description to proc
  target_can_use_run_cmd
- handling the target_description == core &&
  [target_info gdb_protocol] == "extended-remote" case in the proc
- using require {target_can_use_run_cmd core}
such that now in both cases we have:
...
UNSUPPORTED: gdb.tui/corefile-run.exp: require failed: \
  target_can_use_run_cmd core
...

Tested on x86_64-linux.

With test-case gdb.threads/step-bg-decr-pc-switch-thread.exp and target board
native-gdbserver, I run into:
...
(gdb) UNSUPPORTED: gdb.threads/step-bg-decr-pc-switch-thread.exp: \
  switch to main thread
Remote debugging from host ::1, port 43914^M
monitor exit^M
Cannot execute this command while the target is running.^M
Use the "interrupt" command to stop the target^M
and then try again.^M
(gdb) WARNING: Timed out waiting for EOF in server after monitor exit
...

Fix this by following the advice and issuing an interrupt command, allowing
the following monitor exit command to succeed.

Tested on x86_64-linux.

python black formatter was complaining about the formatting of
gdb.python/py-typeprint.py, so this commit corrects it.

PR python/17136 reported an unhandled exception when using typeprinters
only valid on some objfiles, rather than being a global typeprinter. The
fix was accepted without a regression test, and we've been carrying one
out-of-tree for a while but I think it's worth upstreaming. The code
itself was developed by Jan Kratochvil.

Co-Authored-By: Jan Kratochvil <jkratochvil@azul.com>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=17136


Reviewed-By: Andrew Burgess <aburgess@redhat.com>
Approved-By: Tom Tromey <tom@tromey.com>

scalar_binop has code for "&&" and "||", but I think this code can't
currently be run -- and, furthermore, it doesn't make sense to have
this code here, as the point of these operators is to short-circuit
evaluation.

This patch removes the dead code.

Regression tested on x86-64 Fedora 36.

Approved-by: Kevin Buettner <kevinb@redhat.com>

Similar to the arm target documentation situation, the documentation of the
XML features for AArch64 targets is rather brief.  I have received the same
feedback that what gdb carries in the documentation is quite unclear from the
perspective of what debugging servers should define in the XML features, how and
what the outcome is in gdb.

This patch attempts to clarify a bit more what all the possible features are.

The documentation of the XML features for Arm targets is very brief.  I have
received feedback saying it is quite unclear from the perspective of the
debugging servers what should be defined in the XML features, how and
what the outcome is in gdb.

This patch attempts to clarify a bit more what all the possible features are.

gprofng/ChangeLog
2023-03-10  Vladimir Mezentsev  <vladimir.mezentsev@oracle.com>

	gprofng/src/DwarfLib.cc (DwrLineRegs::getPath): Add a DW_AT_comp_dir
	string if the directoty table has relative names.

This changes linetable_entry::is_stmt to type bool, rather than
unsigned.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

objfile_relocate1 introduces new scopes that aren't necessary.  I
noticed this while working on an earlier patch in this series.  This
patch removes these.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Linetables no longer change after they are created.  This patch
applies const to them.

Note there is one hack to cast away const in mdebugread.c.  This code
allocates a linetable using 'malloc', then later copies it to the
obstack.  While this could be cleaned up, I chose not to do so because
I have no way of testing it.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

This changes linetables to not add the text offset to the addresses
they contain.  I did this in a few steps, necessarily combined
together in one patch: I renamed the 'pc' member to 'm_pc', added the
appropriate accessors, and then recompiled.  Then I fixed all the
errors.  Where possible I generally chose to use the raw_pc accessor,
as it is less expensive.

Note that this patch discounts the possibility that the text section
offset might cause wraparound in the addresses in the line table.
However, this was already discounted -- in particular,
objfile_relocate1 did not re-sort the table in this scenario.  (There
was a bug open about this, but as far as I can tell this has never
happened, it's not even clear what inspired that bug.)

Approved-By: Simon Marchi <simon.marchi@efficios.com>

This adds a couple of comparison operators to linetable_entry, and
simplifies both the calls to sort and one other spot that checks for
equality.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

gprofng/ChangeLog
2023-03-10  Vladimir Mezentsev  <vladimir.mezentsev@oracle.com>

	PR gprofng/30195
	gprofng/src/DwarfLib.cc (DwrLineRegs::reset): Set 'file = 1;'.

Some systems may install binutils headers into a system location
(e.g. /usr/local/include on FreeBSD) which may also include headers
for other external packages used by GDB such as zlib or zstd.  If a
system include path such as /usr/local/include is added before local
include paths to directories within a clone or release tarball, then
headers from the external binutils package are used which can result
in build failures if the external binutils package is out of sync with
the version of GDB being built.

To fix, sort the include paths in INTERNAL_CFLAGS_BASE to add CFLAGS
for "local" componenets before external components.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30214


Reviewed-By: Tom Tromey <tom@tromey.com>

Similar to d58854b6 for x86_64.

_Thread_local int a;
int main() { return a; }

% gcc -m32 -fno-plt -fpic a.c -fuse-ld=bfd -Wa,-mrelax-relocations=no
/usr/bin/ld.bfd: /tmp/ccR8Yexy.o: TLS transition from R_386_TLS_GD to R_386_TLS_IE_32 against `a' at 0x15 in section `.text' failed
/usr/bin/ld.bfd: failed to set dynamic section sizes: bad value
collect2: error: ld returned 1 exit status

This commit fixes the issue.

There is an argument that the -fno-plt TLS sequence was added after
R_386_GOT32X was required for call *func@GOT(%ebx), so R_386_GOT32 was
intended to be unsupported.

Unfortunately this standpoint has caused interop difficulty: some
projects specify -mrelax-relocations=no to build relocatable object
files compatible with older linkers (e.g.
https://github.com/IHaskell/IHaskell/issues/636) or do so by accident
(e.g. https://github.com/rust-lang/rust/pull/106511 not addressed as of
today).  Many uses have not been cleaned up in practice, and compiling
with -fno-plt will lead to the `TLS transition from R_386_TLS_GD ...`
error which is hard to reason about.

It seems easier to apply this simple change to prevent the footgun.

    PR ld/24784
    * bfd/elf32-i386.c (elf_i386_check_tls_transition): Allow R_386_GOT32.

_Thread_local int a;
int main() { return a; }

% gcc -fno-plt -fpic a.c -fuse-ld=bfd -Wa,-mrelax-relocations=no
/usr/bin/ld.bfd: /tmp/ccSSBgrg.o: TLS transition from R_X86_64_TLSGD to R_X86_64_GOTTPOFF against `a' at 0xd in section `.text' failed
/usr/bin/ld.bfd: failed to set dynamic section sizes: bad value
collect2: error: ld returned 1 exit status

This commit fixes the issue.

There is an argument that the -fno-plt TLS sequence was added after
R_X86_64_GOTPCRELX was required for call, so R_X86_64_GOTPCREL was
intended to be unsupported.

Unfortunately this standpoint has caused interop difficulty: some
projects specify -mrelax-relocations=no to build relocatable object
files compatible with older linkers (e.g.
https://github.com/IHaskell/IHaskell/issues/636) or do so by accident
(e.g. https://github.com/rust-lang/rust/pull/106511 not addressed as of
today).  Many uses have not been cleaned up in practice, and compiling
with -fno-plt will lead to the `TLS transition from R_X86_64_TLSGD ...`
error which is hard to reason about.

There is another argument which may be weaker but relevant to the
necessity of -mrelax-relocations=no: HWAddressSanitizer x86-64 will
likely need some assembler support to disable relaxation.  Without the
support and if the compiler needs to support many gas version, the
simplest solution would be to use -Wa,-mrelax-relocations=no.

    PR ld/24784
    * bfd/elf64-x86-64.c (elf_x86_64_check_tls_transition): Allow
      R_X86_64_GOTPCREL.

With test-case gdb.python/py-completion.exp and target board
native-extended-gdbserver I get this warning:
...
(gdb) PASS: gdb.python/py-completion.exp: discard #2
completefilecommandcond $outputs/gdb.python/py-completion/py-completion-t^G\
  PASS: gdb.python/py-completion.exp: completefilecommandcond completion
Remote debugging from host ::1, port 53346^M
monitor exit^M
not implemented^M
(gdb) WARNING: Timed out waiting for EOF in server after monitor exit
...

Fix this by adding the missing "discard #3", such that we have instead:
...
(gdb) PASS: gdb.python/py-completion.exp: discard #2
completefilecommandcond $outputs/gdb.python/py-completion/py-completion-t^G\
  PASS: gdb.python/py-completion.exp: completefilecommandcond completion
 ^M
not implemented^M
(gdb) PASS: gdb.python/py-completion.exp: discard #3
Remote debugging from host ::1, port 36278^M
monitor exit^M
(gdb)
...

Tested on x86_64-linux.

[ Using $pp as shorthand for the pagination prompt
"--Type <RET> for more, q to quit, c to continue without paging--". ]

The test-case gdb.python/py-cmd.exp passes, but the handling of the
test_multiline command output looks a bit odd:
...
(gdb) test_multiline
test_multiline output
  ...
test_multiline output
$ppPASS: gdb.python/py-cmd.exp: verify pagination from test_multiline
q
test_multiline
Quit
(gdb) test_multiline
test_multiline output
  ...
test_multiline output
$ppPASS: gdb.python/py-cmd.exp: verify pagination from test_multiline: q
...

What happens is:
- a test_multiline command is issued
- some output is printed, followed by a pagination prompt
- the test-case concludes that pagination occurred, and produces a PASS
- "q\n" is replied to the pagination prompt
- without waiting for response to the "q\n", another test_multiline command is
  issued
- in response to the "q\n" we get "Quit\n(gdb) "
- some output is printed, followed by a pagination prompt
- the test-case concludes that there's a valid response to the "q\n", and
  produces a PASS, consuming the second pagination prompt, but without a reply.

My conclusion is that the second test_multiline command is unintentional, so fix
this by removing it.

Without it, we have the more straightforward:
...
(gdb) test_multiline
test_multiline output
  ...
test_multiline output
$ppPASS: gdb.python/py-cmd.exp: verify pagination from test_multiline
q
Quit
(gdb) PASS: gdb.python/py-cmd.exp: verify pagination from test_multiline: q
...

This also fixes the following warning with target board native-gdbserver:
...
WARNING: Timed out waiting for EOF in server after monitor exit
...

Tested on x86_64-linux.

With test-case gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event.exp
and target board remote-gdbserver-on-localhost, I run into:
...
FAIL: $exp: runto: run to main
...

I can easily fix this using "gdb_load_shlib $binfile_lib", but then run into:
...
(gdb) print all_good^M
$1 = false^M
(gdb) FAIL: $exp: print all_good
info pretty-printer^M
...

Sysroot is set to "target:", so gdb downloads the shared library from the target
(Using $so as shorthand for
libpy-autoloaded-pretty-printers-in-newobjfile-event.so):
...
Reading /home/remote-target/$so from remote target...^M
...
and internally refers to it as "target:/home/remote-target/$so".

In load_auto_scripts_for_objfile, gdb gives up trying to auto-load scripts
for $so once it checks for is_target_filename.

Fix this by declaring auto-load unsupported if sysroot starts with "target:".

Tested on x86_64-linux.

Fix test-case gdb.python/py-event-load.exp for target board
remote-gdbserver-on-localhost using gdb_download_shlib.

Tested on x86_64-linux.

One spot that checks test_compiler_info can be switched to use
'require'.

I found a few more spots that check istarget that can be switched to
use 'require'.