ppc-opc.c: place new instructions at SFFS level

svp64: sync specifiers

ppc/svp64: support optional operands disassembly

ppc/svp64: disassemble branch mode

ppc/svp64: disassemble CR op mode

ppc/svp64: disassemble ld/st idx mode

ppc/svp64: disassemble ld/st imm mode

ppc/svp64: disassemble normal mode

ppc/svp64: disassemble SVP64 operands

ppc/svp64: disassemble SVP64 name

ppc/svp64: obtain SVP64 disassembly context

ppc/svp64: share SVP64 context via libopcodes

ppc/svp64: introduce SVP64 opcode lookup

ppc: decouple print_insn_powerpc_opcode routine

ppc/svp64: reuse md_parse_name in md_operand

ppc/svp64: introduce alias for 1<<%r3 predicate

ppc/svp64: allow predicate macro expansion

ppc/svp64: introduce SVP64 name parser

ppc/svp64: allow w/dw/sw macro expansion

ppc/svp64: remap operands and build instructions

ppc/svp64: support SVP64 vectors

ppc: refactor assembly logic

ppc/svp64: validate and fix modes

ppc/svp64: validate SVP64 context

ppc/svp64: support crm mode

ppc/svp64: support mr/mrr modes

ppc/svp64: support ff/pr modes

ppc/svp64: support zz/dz/sz specifier

ppc/svp64: support sat specifier

ppc/svp64: support sea specifier

ppc/svp64: support els specifier

ppc/svp64: support w/dw/sw modes

ppc/svp64: support vec2/vec3/vec4 modes

ppc/svp64: support m/dm/sm modes

ppc/svp64: introduce svp64_decode stub

ppc/svp64: setup SVP64 opcodes table

opcodes: introduce SVP64 sources

opcodes: introduce SVP64 headers

ppc/svp64: introduce svp64_assemble stub

ppc: share pd_reg definition via libopcodes

ppc/svp64: support shadd/shadduw instructions

ppc/svp64: support divmod2du instruction

ppc/svp64: support maddedu instruction

ppc/svp64: support fptrans instructions

ppc/svp64: support bmask instruction

ppc/svp64: support absd instructions

ppc/svp64: support cprop instructions

ppc/svp64: support avgadd instructions

ppc/svp64: support fishmv instruction

ppc/svp64: support fmvis instruction

ppc/svp64: support svshape2 instruction

https://libre-soc.org/openpower/sv/
https://libre-soc.org/openpower/sv/remap/#svshape
https://libre-soc.org/openpower/sv/remap/#svshape2
https://libre-soc.org/openpower/isa/simplev/

ppc: decouple SFFS and SVP64 extensions

gdb, breakpoint: add breakpoint location debugging logs

Add new commands:

  set debug breakpoint on|off
  show debug breakpoint

This patch introduces new debugging information that prints
breakpoint location insertion and removal flow.

The debug output looks like:
~~~
(gdb) set debug breakpoint on
(gdb) disassemble main
Dump of assembler code for function main:
   0x0000555555555129 <+0>: endbr64
   0x000055555555512d <+4>: push   %rbp
   0x000055555555512e <+5>: mov    %rsp,%rbp
=> 0x0000555555555131 <+8>: mov    $0x0,%eax
   0x0000555555555136 <+13>: pop    %rbp
   0x0000555555555137 <+14>: ret
End of assembler dump.
(gdb) break *0x0000555555555137
Breakpoint 2 at 0x555555555137: file main.c, line 4.
[breakpoint] update_global_location_list: insert_mode = UGLL_MAY_INSERT
(gdb) c
Continuing.
[breakpoint] update_global_location_list: insert_mode = UGLL_INSERT
[breakpoint] insert_bp_location: Breakpoint 2 (0x5565daddb1e0) at address 0x555555555137 in main at main.c:4
[breakpoint] insert_bp_location: Breakpoint -2 (0x5565dab51c10) at address 0x7ffff7fd37b5
[breakpoint] insert_bp_location: Breakpoint -5 (0x5565dab68f30) at address 0x7ffff7fe509e
[breakpoint] insert_bp_location: Breakpoint -7 (0x5565dab694f0) at address 0x7ffff7fe63f4
[breakpoint] remove_breakpoint_1: Breakpoint 2 (0x5565daddb1e0) at address 0x555555555137 in main at main.c:4 due to regular remove
[breakpoint] remove_breakpoint_1: Breakpoint -2 (0x5565dab51c10) at address 0x7ffff7fd37b5 due to regular remove
[breakpoint] remove_breakpoint_1: Breakpoint -5 (0x5565dab68f30) at address 0x7ffff7fe509e due to regular remove
[breakpoint] remove_breakpoint_1: Breakpoint -7 (0x5565dab694f0) at address 0x7ffff7fe63f4 due to regular remove

Breakpoint 2, 0x0000555555555137 in main () at main.c:4
4 }
~~~

Co-Authored-By: Christina Schimpe <christina.schimpe@intel.com>

Automatic date update in version.in

Rename bfd_bread and bfd_bwrite

These were renamed from bfd_read and bfd_write back in 2001 when they
lost an unnecessary parameter.  Rename them back, and get rid of a few
casts that are only needed without prototyped functions (K&R C).

Add ld makefile dependencies

* Makefile.am (EXTRA_ld_new_SOURCES): Add pep-dll-aarch64.c
and pep-dll-x86_64.c.
* Makefile.in: Regenerate.

PR30724, cygwin ld performance regression since 014a602b86

According to the reporter of this bug the newlib fseek implementation
is likely slowed down by locking and fflush, only attempting to
optimise seeks when the file is opened read-only.  Thus when writing
the output we get a dramatic slowdown due to commit 014a602b86.

PR 30724
* bfd.c (enum bfd_last_io): New.
(struct bfd): Add last_io field.
* bfd-in2.h: Regenerate.
* bfd-io.c (bfd_bread, bfd_bwrite): Force seek if last_io is
opposite direction.
(bfd_seek): Reinstate optimisation for seek to same position.

[gdb/build] Use move capture in gdb_demangle

Use move capture in gdb_demangle when compiling for c++14 or higher, to save a
std::string copy.

Tested on x86_64-linux.

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

ld: Fix retain7a.d XFAIL/notarget entry for hppa

PR 30733
* ld/testsuite/ld-elf/retain7a.d: Fix XFAIL entry for hppa to match
  hppa{1.1,2.0}*, like hppa2.0-unknown-linux-gnu which Gentoo uses.

Signed-off-by: Sam James <sam@gentoo.org>

ld: Fix relocatable.d XFAIL/notarget entry for hppa

PR 30734
* ld/testsuite/ld-elf/relocatable.d: Fix notarget entry for hppa to match
  hppa{1.1,2.0}*, like hppa2.0-unknown-linux-gnu which Gentoo uses.

Signed-off-by: Sam James <sam@gentoo.org>

Update my name in maintainers file

Guard against killing unrelated processes in amd64-disp-step.exp

When testing current gdb trunk on Solaris/amd64, the whole session was
reliably terminated by make check.  I could trace this to the following
entry in gdb.arch/amd64-disp-step/gdb.log:

FAIL: gdb.arch/amd64-disp-step.exp: add into rcx: send_signal=on: get
inferior pid
Executing on target: kill -ALRM -1    (timeout = 300)
builtin_spawn -ignore SIGHUP kill -ALRM -1

If $inferior_pid doesn't refer to a single process for some reason, this
kill would terminate either a process group or the whole session.

This patch avoids this by ensuring that the pid arg is positive.

Tested on amd64-pc-solaris2.11 and x86_64-pc-linux-gnu.

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

[gdb/build] Fix build breaker with -std=c++11

When building with -std=c++11 I run into:
...
gdb/dwarf2/cooked-index.c: In member function \
  ‘void cooked_index::start_writing_index(dwarf2_per_bfd*)’:
gdb/dwarf2/cooked-index.c:469:10: error: lambda capture initializers only \
  available with -std=c++14 or -std=gnu++14 [-Werror]
          ctx = std::move (ctx)] ()
          ^~~
...

Fix this by capturing a copy instead when using -std=c++11:
...
    = gdb::thread_pool::g_thread_pool->post_task ([this, per_bfd, ctx] ()
...

Tested by building with and without -stdc=++11 on x86_64-linux.

Reported-By: Tom Tromey <tom@tromey.com>
Reviewed-by: John Baldwin <jhb@FreeBSD.org>

RISC-V: Update ratified 'Ztso' extension version

Because the 'Ztso' extension is now ratified, it has a version number of 1.0
(not 0.1).  This commit updates the number.

bfd/ChangeLog:

* elfxx-riscv.c (riscv_supported_std_z_ext): Update the version
number of the 'Ztso' extension since it's ratified.

Automatic date update in version.in

gprofng: 30700 tmpdir/gp-collect-app_F test fails

gprofng/ChangeLog
2023-08-03  Vladimir Mezentsev  <vladimir.mezentsev@oracle.com>

PR gprofng/30700
* testsuite/gprofng.display/gp-collect-app_F.exp: Fix -name argument
for sub-experiment filtering.

RISC-V: move comment describing rules for riscv_opcodes[]

It makes little sense to have this comment meanwhile over a hundred
lines ahead of the array. In fact until spotting the comment, I was
wondering why those pretty important aspects aren't spelled out
anywhere.

gdb/fortran: Align intrinsic/variable precedence

Fortran allows variables and function to be named after language defined
intrinsics as they are not reserved keywords. For example, the abs maths
intrinsic can be hidden by a user declaring a variable called abs.

The behavior before this patch was to favour the intrinsic, which meant
that any variables named, for example "allocated", could not be
inspected by GDB.

This patch inverts this priority to bring GDB's behaviour closer to the
Fortran language, where the user defined symbol can hide the intrinsic.

Special care was need to prevent any C symbols from overriding either
Fortran intrinsics or user defined variables. This was observed to be
the case when GDB has access to symbols for abs from libm. This was
solved by only allowing symbols not marked with language_fortran to be
overridden.

In total this brings the order of precedence to the following (highest
first):

    1. User defined Fortran variable or function.
    2. Fortran intrinsic.
    3. Symbols from languages other than Fortran.

The sizeof intrinsic is now case insensitive. This is closer to the
Fortran language.  I believe this change is safe enough as it increases
the acceptance of the grammar, rather than restricts it. I.e. it should
not break any existing scripts which rely on it. Unless of course they
rely on SIZEOF being rejected.

GDB built with GCC 13.

No test suite regressions detected. Compilers: GCC, ACfL, Intel, Intel
LLVM, NVHPC; Platforms: x86_64, aarch64.

Existing tests in gdb.fortran cover the invocation of intrinsics
including: intrinsics.exp, shape.exp, rank.exp, lbound-ubound.exp.

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

Automatic date update in version.in

Automatic date update in version.in

[gdb/symtab] Find main language without symtab expansion

When loading an executable using "file a.out", the language is set according
to a.out, which can involve looking up the language of symbol "main", which
will cause the symtab expansion for the containing CU.

Expansion of lto debug info can be slow, so in commit d3214198119 ("[gdb] Use
partial symbol table to find language for main") a feature was added to avoid
the symtab expansion.

This feature stopped working after commit 7f4307436fd ("Fix "start" for D,
Rust, etc").

[ The commit addresses problems related to command start, which requires finding
the main function:
- for language D, "main" was found instead of "D main", and
- for Rust, the correct function was found, but attributed the wrong name
  (not fully qualified). ]

Reimplement the feature by adding
cooked_index_functions::lookup_global_symbol_language.

Tested on x86_64-linux.

PR symtab/30661
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30661

as: Fix typo in manual

The -D flag should enable "debugging"

Automatic date update in version.in

Reindent recursive_dump_type

I noticed that a 'switch' in recursive_dump_type was incorrect
indented.  This patch fixes the problem.  Tested by rebuilding.

Consolidate calls to bfd_set_cacheable

I noticed that some spots in gdb call bfd_set_cacheable after opening
a BFD.

The BFD file cache is a bit odd.  BFDs that are opened locally are
unconditionally registered with the cache, and their underlying file
descriptor will always be closed when bfd_cache_close_all is called.
However, only "cacheable" BFDs will be eligible for reopening when
needed -- and by default BFD decides that if a file descriptor is
passed in, then it should not be cacheable.  If a non-cacheable BFD's
file descriptor is closed, there is no offical way to reopen it.

gdb needs to call bfd_cache_close_all, because some systems cannot
start an executable when it has an open file descriptor referencing
it.

However, gdb also will sometimes passes an open file descriptor to the
various BFD open functions.  And, due to lazy DWARF reading, gdb may
also need to reopen these BFDs.

Rather than having all the callers figure out when exactly to set the
cacheable flag, I think it makes sense to consolidate this logic into
the gdb_bfd.c wrapper functions.  It is ok to do this because gdb
always passes a filename to these open functions, so reopening should
work ok.

Regression tested on x86-64 Fedora 38.

Reviewed-by: John Baldwin <jhb@FreeBSD.org>

Remove extra '.' from error message

A local gdb test failed with this error message:

 Remote communication error.  Target disconnected.: Arg list too long.

The ".:" seemed weird to me.  This patch removes the ".".

Reviewed-by: John Baldwin <jhb@FreeBSD.org>

Fix incorrect class name in free_objfile documentation

The documentation for the Python free_objfile event registry uses the
wrong class name.  This patch fixes it.  I'm checking this in as
obvious.

Fix potential infinite loop in bfd_cache_close_all.

  PR 15545 * cache.c (bfd_cache_close_all): Extend description to note that all files will be closed, even those that are not cacheable. Add code to prevent a possible infinite loop.

[gdb/testsuite] Extend gdb.base/index-cache.exp further

Add lookup of a non-existing symbol to test-case gdb.base/index-cache.exp.

This serves as regression test for PR symtab/30718.

PR symtab/30718
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30718

[gdb/testsuite] Move "maint wait-for-index-cache" ALAP in gdb.base/index-cache.exp

In test-case gdb.base/index-cache.exp proc run_test_with_flags contains:
...
clean_restart ${testfile}

# The tests generally want to check the cache, so make sure it
# has completed its work.
gdb_test_no_output "maintenance wait-for-index-cache"
...

This however hides data races between:
- index-cache writing (due to file $exec), and
- symbol lookups (due to subsequent ptype commands).

Fix this by:
- moving the "maintenance wait-for-index-cache" to proc check_cache_stats, and
- moving all calls to proc check_cache_stats ALAP.

Tested on x86_64-linux.

[gdb/symtab] Fix data race on dwarf2_per_cu_data::{files_read,is_debug_types}

With gdb build with -fsanitize=thread, and the exec from test-case
gdb.base/index-cache.exp, I run into:
...
$ rm -f ~/.cache/gdb/*; \
  gdb -q -batch -iex "set index-cache enabled on" index-cache \
    -ex "print foobar"
  ...
WARNING: ThreadSanitizer: data race (pid=25018)
  Write of size 1 at 0x7b200000410d by main thread:
    #0 dw2_get_file_names_reader gdb/dwarf2/read.c:2033 (gdb+0x7ab023)
    #1 dw2_get_file_names gdb/dwarf2/read.c:2130 (gdb+0x7ab023)
    #2 dw_expand_symtabs_matching_file_matcher(dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>) gdb/dwarf2/read.c:3105 (gdb+0x7ac6e9)
    #3 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16812 (gdb+0x7d040f)
    #4 objfile::map_symtabs_matching_filename(char const*, char const*, gdb::function_view<bool (symtab*)>) gdb/symfile-debug.c:219 (gdb+0xda5b6e)
    #5 iterate_over_symtabs(char const*, gdb::function_view<bool (symtab*)>) gdb/symtab.c:648 (gdb+0xdc441d)
    #6 lookup_symtab(char const*) gdb/symtab.c:662 (gdb+0xdc4522)
    #7 classify_name gdb/c-exp.y:3083 (gdb+0x61afec)
    #8 c_yylex gdb/c-exp.y:3251 (gdb+0x61dd13)
    #9 c_yyparse() build/gdb/c-exp.c.tmp:1988 (gdb+0x61f07e)
    #10 c_parse(parser_state*) gdb/c-exp.y:3417 (gdb+0x62d864)
    #11 language_defn::parser(parser_state*) const gdb/language.c:598 (gdb+0x977245)
    #12 parse_exp_in_context gdb/parse.c:414 (gdb+0xb10b1b)
    #13 parse_expression(char const*, innermost_block_tracker*, enum_flags<parser_flag>) gdb/parse.c:462 (gdb+0xb1112e)
    #14 process_print_command_args gdb/printcmd.c:1321 (gdb+0xb4bf8c)
    #15 print_command_1 gdb/printcmd.c:1335 (gdb+0xb4caaa)
    #16 print_command gdb/printcmd.c:1468 (gdb+0xb4cdda)
    #17 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x65b078)
    #18 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x65ed53)
    #19 execute_command(char const*, int) gdb/top.c:575 (gdb+0xe3a7ea)
    #20 catch_command_errors gdb/main.c:518 (gdb+0xa183fd)
    #21 execute_cmdargs gdb/main.c:617 (gdb+0xa185bf)
    #22 captured_main_1 gdb/main.c:1289 (gdb+0xa1aad8)
    #23 captured_main gdb/main.c:1310 (gdb+0xa1b9da)
    #24 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xa1b9da)
    #25 main gdb/gdb.c:39 (gdb+0x42506a)

  Previous read of size 1 at 0x7b200000410d by thread T2:
    #0 write_gdbindex gdb/dwarf2/index-write.c:1214 (gdb+0x75bb30)
    #1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1469 (gdb+0x75f803)
    #2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/index-cache.c:173 (gdb+0x755a36)
    #3 cooked_index::maybe_write_index(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/cooked-index.c:642 (gdb+0x71c96d)
    #4 operator() gdb/dwarf2/cooked-index.c:471 (gdb+0x71c96d)
    #5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x71c96d)
    #6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x72a57c)
    #7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x72a5db)
    #8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72a5db)
    #9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x72a5db)
    #10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x72a5db)
    #11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x72a5db)
    #12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x724954)
    #13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x724954)
    #14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x72434a)
    #15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72434a)
    #16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x72434a)
    #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x72434a)
    #18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x72434a)
    #19 pthread_once <null> (libtsan.so.0+0x4457c)
    #20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72532b)
    #21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x72532b)
    #22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x174570d)
    #23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x174570d)
    #24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x174570d)
    #25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x174570d)
    #26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x17480c0)
    #27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x17480c0)
    #28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x17480c0)
    #29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x17480c0)
    #30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x17480c0)
    #31 <null> <null> (libstdc++.so.6+0xdcac2)
  ...
SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:2033 in dw2_get_file_names_reader
...

The race happens when issuing the "file $exec" command.

The race is between:
- a worker thread writing the index cache, and in the process reading
  dwarf2_per_cu_data::is_debug_type, and
- the main thread writing to dwarf2_per_cu_data::files_read.

The two bitfields dwarf2_per_cu_data::files_read and
dwarf2_per_cu_data::is_debug_type share the same bitfield container.

Fix this by making dwarf2_per_cu_data::files_read a packed<bool, 1>.

Tested on x86_64-linux.

PR symtab/30718
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30718

[gdb/symtab] Fix data race on dwarf2_per_cu_data::{mark,is_debug_types}

With gdb build with -fsanitize=thread, and the exec from test-case
gdb.base/index-cache.exp, I run into:
...
$ rm -f ~/.cache/gdb/*; \
  gdb -q -batch -iex "set index-cache enabled on" index-cache \
    -ex "print foobar"
  ...
WARNING: ThreadSanitizer: data race (pid=23970)
  Write of size 1 at 0x7b200000410d by main thread:
    #0 dw_expand_symtabs_matching_file_matcher(dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>) gdb/dwarf2/read.c:3077 (gdb+0x7ac54e)
    #1 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16812 (gdb+0x7d039f)
    #2 objfile::map_symtabs_matching_filename(char const*, char const*, gdb::function_view<bool (symtab*)>) gdb/symfile-debug.c:219 (gdb+0xda5aee)
    #3 iterate_over_symtabs(char const*, gdb::function_view<bool (symtab*)>) gdb/symtab.c:648 (gdb+0xdc439d)
    #4 lookup_symtab(char const*) gdb/symtab.c:662 (gdb+0xdc44a2)
    #5 classify_name gdb/c-exp.y:3083 (gdb+0x61afec)
    #6 c_yylex gdb/c-exp.y:3251 (gdb+0x61dd13)
    #7 c_yyparse() build/gdb/c-exp.c.tmp:1988 (gdb+0x61f07e)
    #8 c_parse(parser_state*) gdb/c-exp.y:3417 (gdb+0x62d864)
    #9 language_defn::parser(parser_state*) const gdb/language.c:598 (gdb+0x9771c5)
    #10 parse_exp_in_context gdb/parse.c:414 (gdb+0xb10a9b)
    #11 parse_expression(char const*, innermost_block_tracker*, enum_flags<parser_flag>) gdb/parse.c:462 (gdb+0xb110ae)
    #12 process_print_command_args gdb/printcmd.c:1321 (gdb+0xb4bf0c)
    #13 print_command_1 gdb/printcmd.c:1335 (gdb+0xb4ca2a)
    #14 print_command gdb/printcmd.c:1468 (gdb+0xb4cd5a)
    #15 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x65b078)
    #16 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x65ed53)
    #17 execute_command(char const*, int) gdb/top.c:575 (gdb+0xe3a76a)
    #18 catch_command_errors gdb/main.c:518 (gdb+0xa1837d)
    #19 execute_cmdargs gdb/main.c:617 (gdb+0xa1853f)
    #20 captured_main_1 gdb/main.c:1289 (gdb+0xa1aa58)
    #21 captured_main gdb/main.c:1310 (gdb+0xa1b95a)
    #22 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xa1b95a)
    #23 main gdb/gdb.c:39 (gdb+0x42506a)

  Previous read of size 1 at 0x7b200000410d by thread T1:
    #0 write_gdbindex gdb/dwarf2/index-write.c:1214 (gdb+0x75bb30)
    #1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1469 (gdb+0x75f803)
    #2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/index-cache.c:173 (gdb+0x755a36)
    #3 cooked_index::maybe_write_index(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/cooked-index.c:642 (gdb+0x71c96d)
    #4 operator() gdb/dwarf2/cooked-index.c:471 (gdb+0x71c96d)
    #5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x71c96d)
    #6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x72a57c)
    #7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x72a5db)
    #8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72a5db)
    #9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x72a5db)
    #10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x72a5db)
    #11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x72a5db)
    #12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x724954)
    #13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x724954)
    #14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x72434a)
    #15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72434a)
    #16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x72434a)
    #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x72434a)
    #18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x72434a)
    #19 pthread_once <null> (libtsan.so.0+0x4457c)
    #20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72532b)
    #21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x72532b)
    #22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x174568d)
    #23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x174568d)
    #24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x174568d)
    #25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x174568d)
    #26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1748040)
    #27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1748040)
    #28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1748040)
    #29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1748040)
    #30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1748040)
    #31 <null> <null> (libstdc++.so.6+0xdcac2)
  ...
SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:3077 in dw_expand_symtabs_matching_file_matcher(dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>)
...

The race happens when issuing the "file $exec" command.

The race is between:
- a worker thread writing the index cache, and in the process reading
  dwarf2_per_cu_data::is_debug_type, and
- the main thread writing to dwarf2_per_cu_data::mark.

The two bitfields dwarf2_per_cu_data::mark and
dwarf2_per_cu_data::is_debug_type share the same bitfield container.

Fix this by making dwarf2_per_cu_data::mark a packed<unsigned int, 1>.

Tested on x86_64-linux.

PR symtab/30718
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30718

[gdb/testsuite] Extend gdb.base/index-cache.exp

The test-case gdb.base/index-cache.exp uses only one source file, which
contains main.

While doing "file $exec", in set_initial_language a symbol lookup of "main" is
done, causing the symtab containing main to be expanded.

Handling of main is special, and a future optimization may skip the lookup and
expansion.

Reliably exercise:
- the lookup of main, expanding the symtab containing main, by doing
  "ptype main", and
- the lookup of another symbol, expanding a symtab not containing main, by:
  - adding another source file containing function foo, and
  - doing "ptype foo".

This triggered a segfault with target board native-extended-gdbserver, filed
as PR symtab/30712, but that seems to be fixed by a previous commit in this
series.

Tested on x86_64-linux.

Approved-By: Tom Tromey <tom@tromey.com>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30712

[gdb/symtab] Fix data race on dwarf2_per_cu_data::{m_header_read_in,is_debug_type}

With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp
and target board debug-types, I run into:
...
(gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache
Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache...
==================
WARNING: ThreadSanitizer: data race (pid=9654)
  Write of size 1 at 0x7b200000420d by main thread:
    #0 dwarf2_per_cu_data::get_header() const gdb/dwarf2/read.c:21513 (gdb+0x8d1eee)
    #1 dwarf2_per_cu_data::addr_size() const gdb/dwarf2/read.c:21524 (gdb+0x8d1f4e)
    #2 dwarf2_cu::addr_type() const gdb/dwarf2/cu.c:112 (gdb+0x806327)
    #3 set_die_type gdb/dwarf2/read.c:21932 (gdb+0x8d3870)
    #4 read_base_type gdb/dwarf2/read.c:15448 (gdb+0x8bcacb)
    #5 read_type_die_1 gdb/dwarf2/read.c:19832 (gdb+0x8cc0a5)
    #6 read_type_die gdb/dwarf2/read.c:19767 (gdb+0x8cbe6d)
    #7 lookup_die_type gdb/dwarf2/read.c:19739 (gdb+0x8cbdc7)
    #8 die_type gdb/dwarf2/read.c:19593 (gdb+0x8cb68a)
    #9 read_subroutine_type gdb/dwarf2/read.c:14648 (gdb+0x8b998e)
    #10 read_type_die_1 gdb/dwarf2/read.c:19792 (gdb+0x8cbf2f)
    #11 read_type_die gdb/dwarf2/read.c:19767 (gdb+0x8cbe6d)
    #12 read_func_scope gdb/dwarf2/read.c:10154 (gdb+0x8a4f36)
    #13 process_die gdb/dwarf2/read.c:6667 (gdb+0x898daa)
    #14 read_file_scope gdb/dwarf2/read.c:7682 (gdb+0x89bad8)
    #15 process_die gdb/dwarf2/read.c:6654 (gdb+0x898ced)
    #16 process_full_comp_unit gdb/dwarf2/read.c:6418 (gdb+0x8981de)
    #17 process_queue gdb/dwarf2/read.c:5690 (gdb+0x894433)
    #18 dw2_do_instantiate_symtab gdb/dwarf2/read.c:1770 (gdb+0x88623a)
    #19 dw2_instantiate_symtab gdb/dwarf2/read.c:1792 (gdb+0x886300)
    #20 dw2_expand_symtabs_matching_one(dwarf2_per_cu_data*, dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>, gdb::function_view<bool (compunit_symtab*)>) gdb/dwarf2/read.c:3042 (gdb+0x88b1f1)
    #21 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16917 (gdb+0x8c228e)
    #22 objfile::lookup_symbol(block_enum, char const*, domain_enum) gdb/symfile-debug.c:288 (gdb+0xf39055)
    #23 lookup_symbol_via_quick_fns gdb/symtab.c:2385 (gdb+0xf66ab7)
    #24 lookup_symbol_in_objfile gdb/symtab.c:2516 (gdb+0xf6711b)
    #25 operator() gdb/symtab.c:2562 (gdb+0xf67272)
    #26 operator() gdb/../gdbsupport/function-view.h:305 (gdb+0xf776b1)
    #27 _FUN gdb/../gdbsupport/function-view.h:299 (gdb+0xf77708)
    #28 gdb::function_view<bool (objfile*)>::operator()(objfile*) const gdb/../gdbsupport/function-view.h:289 (gdb+0xc3fc97)
    #29 svr4_iterate_over_objfiles_in_search_order gdb/solib-svr4.c:3455 (gdb+0xecae47)
    #30 gdbarch_iterate_over_objfiles_in_search_order(gdbarch*, gdb::function_view<bool (objfile*)>, objfile*) gdb/gdbarch.c:5041 (gdb+0x537cad)
    #31 lookup_global_or_static_symbol gdb/symtab.c:2559 (gdb+0xf674fb)
    #32 lookup_global_symbol(char const*, block const*, domain_enum) gdb/symtab.c:2615 (gdb+0xf67780)
    #33 language_defn::lookup_symbol_nonlocal(char const*, block const*, domain_enum) const gdb/symtab.c:2447 (gdb+0xf66d6e)
    #34 lookup_symbol_aux gdb/symtab.c:2123 (gdb+0xf65cb3)
    #35 lookup_symbol_in_language(char const*, block const*, domain_enum, language, field_of_this_result*) gdb/symtab.c:1931 (gdb+0xf64dab)
    #36 set_initial_language() gdb/symfile.c:1708 (gdb+0xf43074)
    #37 symbol_file_add_main_1 gdb/symfile.c:1212 (gdb+0xf41608)
    #38 symbol_file_command(char const*, int) gdb/symfile.c:1681 (gdb+0xf42faf)
    #39 file_command gdb/exec.c:554 (gdb+0x94ff29)
    #40 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x6d9528)
    #41 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x6e0f69)
    #42 execute_command(char const*, int) gdb/top.c:575 (gdb+0xff379c)
    #43 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94b5bc)
    #44 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94bc79)
    #45 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x1034efc)
    #46 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94ab61)
    #47 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11be4ef)
    #48 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a960)
    #49 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94aa21)
    #50 stdin_event_handler gdb/ui.c:155 (gdb+0x10751a0)
    #51 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d95bac)
    #52 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d962e4)
    #53 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d946d0)
    #54 start_event_loop gdb/main.c:412 (gdb+0xb5ab52)
    #55 captured_command_loop gdb/main.c:476 (gdb+0xb5ad41)
    #56 captured_main gdb/main.c:1320 (gdb+0xb5cec1)
    #57 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5cf70)
    #58 main gdb/gdb.c:32 (gdb+0x416776)

  Previous read of size 1 at 0x7b200000420d by thread T11:
    #0 write_gdbindex gdb/dwarf2/index-write.c:1229 (gdb+0x831630)
    #1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1484 (gdb+0x832897)
    #2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/index-cache.c:173 (gdb+0x82db8d)
    #3 cooked_index::maybe_write_index(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/cooked-index.c:645 (gdb+0x7f1d49)
    #4 operator() gdb/dwarf2/cooked-index.c:474 (gdb+0x7f0f31)
    #5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f2a13)
    #6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952)
    #7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0)
    #8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91)
    #9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59)
    #10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660)
    #11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c)
    #12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623)
    #13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf)
    #14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f)
    #15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5)
    #16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d)
    #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2)
    #18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2)
    #19 pthread_once <null> (libtsan.so.0+0x4457c)
    #20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd)
    #21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224)
    #22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852)
    #23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef)
    #24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dad25a)
    #25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dacb7c)
    #26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dadc2b)
    #27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dad05c)
    #28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1db038e)
    #29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1db0319)
    #30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1db02ce)
    #31 <null> <null> (libstdc++.so.6+0xdcac2)
  ...
SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:21513 in dwarf2_per_cu_data::get_header() const
...

The race happens when issuing the "file $exec" command.

The race is between:
- a worker thread writing the index cache, and in the process reading
   dwarf2_per_cu_data::is_debug_type, and
- the main thread writing to dwarf2_per_cu_data::m_header_read_in.

The two bitfields dwarf2_per_cu_data::m_header_read_in and
dwarf2_per_cu_data::is_debug_type share the same bitfield container.

Fix this by making dwarf2_per_cu_data::m_header_read_in a packed<bool, 1>.

Tested on x86_64-linux.

Approved-By: Tom Tromey <tom@tromey.com>
PR symtab/30392
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392

[gdb/symtab] Fix race on dwarf2_per_cu_data::{queued,is_debug_type}

With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp I
run into:
...
(gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache
Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache...
==================
WARNING: ThreadSanitizer: data race (pid=24296)
  Write of size 1 at 0x7b200000420d by main thread:
    #0 queue_comp_unit gdb/dwarf2/read.c:5564 (gdb+0x8939ce)
    #1 dw2_do_instantiate_symtab gdb/dwarf2/read.c:1754 (gdb+0x885b96)
    #2 dw2_instantiate_symtab gdb/dwarf2/read.c:1792 (gdb+0x885d86)
    #3 dw2_expand_symtabs_matching_one(dwarf2_per_cu_data*, dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>, gdb::function_view<bool (compunit_symtab*)>) gdb/dwarf2/read.c:3042 (gdb+0x88ac77)
    #4 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16915 (gdb+0x8c1c8a)
    #5 objfile::lookup_symbol(block_enum, char const*, domain_enum) gdb/symfile-debug.c:288 (gdb+0xf389a1)
    #6 lookup_symbol_via_quick_fns gdb/symtab.c:2385 (gdb+0xf66403)
    #7 lookup_symbol_in_objfile gdb/symtab.c:2516 (gdb+0xf66a67)
    #8 operator() gdb/symtab.c:2562 (gdb+0xf66bbe)
    #9 operator() gdb/../gdbsupport/function-view.h:305 (gdb+0xf76ffd)
    #10 _FUN gdb/../gdbsupport/function-view.h:299 (gdb+0xf77054)
    #11 gdb::function_view<bool (objfile*)>::operator()(objfile*) const gdb/../gdbsupport/function-view.h:289 (gdb+0xc3f5e3)
    #12 svr4_iterate_over_objfiles_in_search_order gdb/solib-svr4.c:3455 (gdb+0xeca793)
    #13 gdbarch_iterate_over_objfiles_in_search_order(gdbarch*, gdb::function_view<bool (objfile*)>, objfile*) gdb/gdbarch.c:5041 (gdb+0x537cad)
    #14 lookup_global_or_static_symbol gdb/symtab.c:2559 (gdb+0xf66e47)
    #15 lookup_global_symbol(char const*, block const*, domain_enum) gdb/symtab.c:2615 (gdb+0xf670cc)
    #16 language_defn::lookup_symbol_nonlocal(char const*, block const*, domain_enum) const gdb/symtab.c:2447 (gdb+0xf666ba)
    #17 lookup_symbol_aux gdb/symtab.c:2123 (gdb+0xf655ff)
    #18 lookup_symbol_in_language(char const*, block const*, domain_enum, language, field_of_this_result*) gdb/symtab.c:1931 (gdb+0xf646f7)
    #19 set_initial_language() gdb/symfile.c:1708 (gdb+0xf429c0)
    #20 symbol_file_add_main_1 gdb/symfile.c:1212 (gdb+0xf40f54)
    #21 symbol_file_command(char const*, int) gdb/symfile.c:1681 (gdb+0xf428fb)
    #22 file_command gdb/exec.c:554 (gdb+0x94f875)
    #23 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x6d9528)
    #24 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x6e0f69)
    #25 execute_command(char const*, int) gdb/top.c:575 (gdb+0xff3166)
    #26 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94af08)
    #27 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94b5c5)
    #28 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x10348c6)
    #29 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94a4ad)
    #30 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11bdf87)
    #31 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a2ac)
    #32 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94a36d)
    #33 stdin_event_handler gdb/ui.c:155 (gdb+0x1074b6a)
    #34 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d9502c)
    #35 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d95764)
    #36 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d93b50)
    #37 start_event_loop gdb/main.c:412 (gdb+0xb5a49e)
    #38 captured_command_loop gdb/main.c:476 (gdb+0xb5a68d)
    #39 captured_main gdb/main.c:1320 (gdb+0xb5c80d)
    #40 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5c8bc)
    #41 main gdb/gdb.c:32 (gdb+0x416776)

  Previous read of size 1 at 0x7b200000420d by thread T12:
    #0 write_gdbindex gdb/dwarf2/index-write.c:1229 (gdb+0x8310c8)
    #1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1484 (gdb+0x83232f)
    #2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context*) gdb/dwarf2/index-cache.c:177 (gdb+0x82d62b)
    #3 cooked_index::maybe_write_index(dwarf2_per_bfd*) gdb/dwarf2/cooked-index.c:640 (gdb+0x7f1bf7)
    #4 operator() gdb/dwarf2/cooked-index.c:470 (gdb+0x7f0f40)
    #5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f2909)
    #6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952)
    #7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0)
    #8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91)
    #9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59)
    #10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660)
    #11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c)
    #12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623)
    #13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf)
    #14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f)
    #15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5)
    #16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d)
    #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2)
    #18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2)
    #19 pthread_once <null> (libtsan.so.0+0x4457c)
    #20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd)
    #21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224)
    #22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852)
    #23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef)
    #24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dac6da)
    #25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dabffc)
    #26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dad0ab)
    #27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dac4dc)
    #28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1daf80e)
    #29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1daf799)
    #30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1daf74e)
    #31 <null> <null> (libstdc++.so.6+0xdcac2)
 ...
SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:5564 in queue_comp_unit
...

The race happens when issuing the "file $exec" command.

The race is between:
- a worker thread writing the index cache, and in the process reading
  dwarf2_per_cu_data::is_debug_type, and
- the main thread expanding the CU containing main, and in the process setting
  dwarf2_per_cu_data::queued.

The two bitfields dwarf2_per_cu_data::queue and
dwarf2_per_cu_data::is_debug_type share the same bitfield container.

Fix this by making dwarf2_per_cu_data::queued a packed<bool, 1>.

Tested on x86_64-linux.

Approved-By: Tom Tromey <tom@tromey.com>
PR symtab/30392
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392

[gdb/symtab] Fix data race on bfd::{cacheable,format}

With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp I
run into:
...
(gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache
Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache...
==================
WARNING: ThreadSanitizer: data race (pid=12261)
  Write of size 4 at 0x7b4400097d08 by main thread:
    #0 bfd_open_file bfd/cache.c:584 (gdb+0x148bb92)
    #1 bfd_cache_lookup_worker bfd/cache.c:261 (gdb+0x148b12a)
    #2 cache_bseek bfd/cache.c:289 (gdb+0x148b324)
    #3 bfd_seek bfd/bfdio.c:459 (gdb+0x1489c31)
    #4 _bfd_generic_get_section_contents bfd/libbfd.c:1069 (gdb+0x14977a4)
    #5 bfd_get_section_contents bfd/section.c:1606 (gdb+0x149cc7c)
    #6 gdb_bfd_scan_elf_dyntag(int, bfd*, unsigned long*, unsigned long*) gdb/solib.c:1601 (gdb+0xed8eca)
    #7 elf_locate_base gdb/solib-svr4.c:705 (gdb+0xec28ac)
    #8 svr4_iterate_over_objfiles_in_search_order gdb/solib-svr4.c:3430 (gdb+0xeca55d)
    #9 gdbarch_iterate_over_objfiles_in_search_order(gdbarch*, gdb::function_view<bool (objfile*)>, objfile*) gdb/gdbarch.c:5041 (gdb+0x537cad)
    #10 find_main_name gdb/symtab.c:6270 (gdb+0xf743a5)
    #11 main_language() gdb/symtab.c:6313 (gdb+0xf74499)
    #12 set_initial_language() gdb/symfile.c:1700 (gdb+0xf4285c)
    #13 symbol_file_add_main_1 gdb/symfile.c:1212 (gdb+0xf40e2a)
    #14 symbol_file_command(char const*, int) gdb/symfile.c:1681 (gdb+0xf427d1)
    #15 file_command gdb/exec.c:554 (gdb+0x94f74b)
    #16 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x6d9528)
    #17 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x6e0f69)
    #18 execute_command(char const*, int) gdb/top.c:575 (gdb+0xff303c)
    #19 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94adde)
    #20 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94b49b)
    #21 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x103479c)
    #22 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94a383)
    #23 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11bde5d)
    #24 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a182)
    #25 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94a243)
    #26 stdin_event_handler gdb/ui.c:155 (gdb+0x1074a40)
    #27 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d94f02)
    #28 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d9563a)
    #29 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d93a26)
    #30 start_event_loop gdb/main.c:412 (gdb+0xb5a374)
    #31 captured_command_loop gdb/main.c:476 (gdb+0xb5a563)
    #32 captured_main gdb/main.c:1320 (gdb+0xb5c6e3)
    #33 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5c792)
    #34 main gdb/gdb.c:32 (gdb+0x416776)

  Previous read of size 1 at 0x7b4400097d08 by thread T12:
    #0 bfd_check_format_matches bfd/format.c:323 (gdb+0x1492db4)
    #1 bfd_check_format bfd/format.c:94 (gdb+0x1492104)
    #2 build_id_bfd_get(bfd*) gdb/build-id.c:42 (gdb+0x6648f7)
    #3 index_cache::store(dwarf2_per_bfd*, index_cache_store_context*) gdb/dwarf2/index-cache.c:110 (gdb+0x82d205)
    #4 cooked_index::maybe_write_index(dwarf2_per_bfd*) gdb/dwarf2/cooked-index.c:640 (gdb+0x7f1bf1)
    #5 operator() gdb/dwarf2/cooked-index.c:470 (gdb+0x7f0f40)
    #6 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f28f7)
    #7 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952)
    #8 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0)
    #9 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91)
    #10 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59)
    #11 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660)
    #12 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c)
    #13 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623)
    #14 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf)
    #15 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f)
    #16 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5)
    #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d)
    #18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2)
    #19 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2)
    #20 pthread_once <null> (libtsan.so.0+0x4457c)
    #21 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd)
    #22 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224)
    #23 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852)
    #24 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef)
    #25 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dac5b0)
    #26 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dabed2)
    #27 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dacf81)
    #28 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dac3b2)
    #29 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1daf6e4)
    #30 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1daf66f)
    #31 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1daf624)
    #32 <null> <null> (libstdc++.so.6+0xdcac2)
  ...
SUMMARY: ThreadSanitizer: data race bfd/cache.c:584 in bfd_open_file
...

The race happens when issuing the "file $exec" command.

The race is between:
- a worker thread getting the build id while writing the index cache, and in
  the process reading bfd::format, and
- the main thread calling find_main_name, and in the process setting
  bfd::cacheable.

The two bitfields bfd::cacheable and bfd::format share the same bitfield
container.

Fix this by capturing the build id in the main thread, and using the captured
value in the worker thread.

Likewise for the dwz build id, which likely suffers from the same issue.

While we're at it, also move the creation of the cache directory to
the index_cache_store_context constructor, to:
- make sure there's no race between subsequent file commands, and
- issue any related warning or error messages during the file command.

Tested on x86_64-linux.

Approved-By: Tom Tromey <tom@tromey.com>
PR symtab/30392
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392

[gdb/symtab] Fix data race on index_cache::m_enabled

With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp I
run into:
...
(gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache
Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache...
(gdb) show index-cache enabled
The index cache is off.
(gdb) PASS: gdb.base/index-cache.exp: test_basic_stuff: index-cache is disabled by default
set index-cache enabled on
==================
WARNING: ThreadSanitizer: data race (pid=32248)
  Write of size 1 at 0x00000321f540 by main thread:
    #0 index_cache::enable() gdb/dwarf2/index-cache.c:76 (gdb+0x82cfdd)
    #1 set_index_cache_enabled_command gdb/dwarf2/index-cache.c:270 (gdb+0x82d9af)
    #2 bool setting::set<bool>(bool const&) gdb/command.h:353 (gdb+0x6fe5f2)
    #3 do_set_command(char const*, int, cmd_list_element*) gdb/cli/cli-setshow.c:414 (gdb+0x6fcd21)
    #4 execute_command(char const*, int) gdb/top.c:567 (gdb+0xff2e64)
    #5 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94acc0)
    #6 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94b37d)
    #7 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x103467e)
    #8 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94a265)
    #9 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11bdd3f)
    #10 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a064)
    #11 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94a125)
    #12 stdin_event_handler gdb/ui.c:155 (gdb+0x1074922)
    #13 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d94de4)
    #14 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d9551c)
    #15 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d93908)
    #16 start_event_loop gdb/main.c:412 (gdb+0xb5a256)
    #17 captured_command_loop gdb/main.c:476 (gdb+0xb5a445)
    #18 captured_main gdb/main.c:1320 (gdb+0xb5c5c5)
    #19 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5c674)
    #20 main gdb/gdb.c:32 (gdb+0x416776)

  Previous read of size 1 at 0x00000321f540 by thread T12:
    #0 index_cache::enabled() const gdb/dwarf2/index-cache.h:48 (gdb+0x82e1a6)
    #1 index_cache::store(dwarf2_per_bfd*) gdb/dwarf2/index-cache.c:94 (gdb+0x82d0bc)
    #2 cooked_index::maybe_write_index(dwarf2_per_bfd*) gdb/dwarf2/cooked-index.c:638 (gdb+0x7f1b97)
    #3 operator() gdb/dwarf2/cooked-index.c:468 (gdb+0x7f0f24)
    #4 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f285b)
    #5 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952)
    #6 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0)
    #7 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91)
    #8 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59)
    #9 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660)
    #10 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c)
    #11 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623)
    #12 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf)
    #13 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f)
    #14 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5)
    #15 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d)
    #16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2)
    #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2)
    #18 pthread_once <null> (libtsan.so.0+0x4457c)
    #19 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd)
    #20 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224)
    #21 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852)
    #22 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef)
    #23 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dac492)
    #24 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dabdb4)
    #25 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dace63)
    #26 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dac294)
    #27 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1daf5c6)
    #28 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1daf551)
    #29 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1daf506)
    #30 <null> <null> (libstdc++.so.6+0xdcac2)

  Location is global 'global_index_cache' of size 48 at 0x00000321f520 (gdb+0x00000321f540)
  ...
SUMMARY: ThreadSanitizer: data race gdb/dwarf2/index-cache.c:76 in index_cache::enable()
...

The race happens when issuing a "file $exec" command followed by a
"set index-cache enabled on" command.

The race is between:
- a worker thread reading index_cache::m_enabled to determine whether an
  index-cache entry for $exec needs to be written
  (due to command "file $exec"), and
- the main thread setting index_cache::m_enabled
  (due to command "set index-cache enabled on").

Fix this by capturing the value of index_cache::m_enabled in the main thread,
and using the captured value in the worker thread.

Tested on x86_64-linux.

PR symtab/30392
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392

ppc: sanity check writing relocs

Check for output buffer overruns.

* elf32-ppc.c (swap_reloc_out, count_and_swap_reloc_out): New
functions.  Use throughout file.
* elf64-ppc.c (swap_reloc_out, count_and_swap_reloc_out): Likewise.

PR30697, ppc32 mix of local-dynamic and global-dynamic TLS

This fixes miscounting of dynamic relocations on GOT entries when
a) there are both local-dynamic and global-dynamic tls accesss for a
   given symbol, and
b) the symbol is global with non-default visibility, and
c) the __tls_get_addr calls aren't optimised away.

PR 30697
bfd/
* elf32-ppc.c (allocate_dynrelocs): Correct local-dynamic
reloc count.
ld/
* testsuite/ld-powerpc/tls32ldgd.d,
* testsuite/ld-powerpc/tls32ldgd.s: New test.
* testsuite/ld-powerpc/powerpc.exp: Run it.

gdb/testsuite: Disable gdb.compile when testing with clang

Attempting to test the gdb.compile with clang as the compiler results in
over 300 unexpected errors, due to a segmentation fault and several
handshake failures. Since the whole feature is designed around a gcc
plugin, and even the gcc testing is shaky at best, this commit restricts
those tests to only running under gcc. If that gets fixed, this commit
can be reverted.

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

Automatic date update in version.in

[gdb/symtab] Remove superfluous handling of Ada main in write_cooked_index

I filed PR29179 about the following FAIL in test-case
gdb.ada/O2_float_param.exp with target board cc-with-gdb-index:
...
(gdb) break increment^M
Function "increment" not defined.^M
Make breakpoint pending on future shared library load? (y or [n]) n^M
(gdb) FAIL: gdb.ada/O2_float_param.exp: scenario=all: gdb_breakpoint: \
  set breakpoint at increment
...

The FAIL was a regression since commit 2cf349be0e3 ("Do not put linkage names
into .gdb_index").

Before that commit we had:
...
$ readelf -w foo > READELF
$ grep callee.*increment READELF
[1568] callee__increment: 5 [global, function]
[3115] callee.increment: 5 [global, function]
...
but after only:
...
$ grep callee.*increment READELF
[3115] callee.increment: 5 [global, function]
...

The regression was fixed by commit 67e83a0deef ("Fix regression in
c-linkage-name.exp with gdb index"), which got us again:
...
$ grep callee.*increment READELF
[1568] callee__increment: 5 [global, function]
[3115] callee.increment: 5 [global, function]
...

The commit however did not claim that particular PR.  A subsequent commit,
commit 5fea9794325 ("Improve Ada support in .gdb_index") did claim to fix it,
together with commit dd05fc7071a ("Change .gdb_index de-duplication
implementation").

The commit 5fea9794325 contained the following addition in write_cooked_index:
...
+      if (entry->per_cu->lang () == language_ada)
+ {
+   /* We want to ensure that the Ada main function's name
+      appears verbatim in the index.  However, this name will
+      be of the form "_ada_mumble", and will be rewritten by
+      ada_decode.  So, recognize it specially here and add it
+      to the index by hand.  */
+   if (entry->tag == DW_TAG_subprogram
+       && strcmp (main_for_ada, name) == 0)
+     {
+       /* Leave it alone.  */
+     }
+   else
+     {
+       /* In order for the index to work when read back into
+  gdb, it has to use the encoded name, with any
+  suffixes stripped.  */
+       std::string encoded = ada_encode (name, false);
+       name = obstack_strdup (&symtab->m_string_obstack,
+      encoded.c_str ());
+     }
+ }
...

The code contains some special handling related to the Ada main function, so
let's look at that one: foo.  Before commit 67e83a0deef we have:
...
$ grep foo.*function READELF
[3733] foo: 7 [global, function]
...
and after:
...
$ grep foo.*function READELF
[2738] _ada_foo: 7 [global, function]
[3733] foo: 7 [global, function]
...
so that looks identical to the callee.increment case.

At commit 5fea9794325, we have slightly different index numbers:
...
$ grep foo.*function READELF
[1658] foo: 7 [global, function]
[2738] _ada_foo: 7 [global, function]
...
but otherwise the same result.

If we disable the special handling of the Ada main function like so:
...
-   if (entry->tag == DW_TAG_subprogram
+   if (false && entry->tag == DW_TAG_subprogram
...
we still have the exact same result because:
...
(gdb) p main_for_ada
$1 = 0x352e6a0 "_ada_foo"
...
and ada_encode ("_ada_foo", false) == "_ada_foo".

The comment seems to be copied from debug_names::insert, which does indeed use
ada_decode, while the code in write_cooked_index uses ada_encode instead.

Remove the superfluous special handling of Ada main in write_cooked_index.

Tested on x86_64-linux, with target boards unix and cc-with-gdb-index.

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

Remove f-string from DAP

One more f-string snuck into the DAP code, in breakpoint.py.  Most of
them were removed here:

    https://sourceware.org/pipermail/gdb-patches/2023-June/200023.html

but I think this one landed after that patch.

While DAP only supports Python 3.5 and later, f-strings were added in
3.6, so remove this.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30708

Use frame.name() in FrameDecorator

A co-worker pointed out that gdb's DAP implementation might return an
integer for the name of a stack frame, like:

    {"id": 1, "name": 93824992310799, ...}

This can be seen currently in the logs of the bt-nodebug.exp test
case.

What is happening is that FrameDecorator falls back on returning the
PC when the frame's function symbol cannot be found, relying on the
gdb core to look up the minsym and print its name.

This can actually yield the wrong answer sometimes, because it falls
into the get_frame_pc / get_frame_address_in_block problem -- if the
frame is at a call to a noreturn function, the PC in this case might
appear to be in the next function in memory.  For more on this, see:

    https://sourceware.org/bugzilla/show_bug.cgi?id=8416

and related bugs.

However, there's a different approach we can take: the code here can
simply use Frame.name.  This handles the PC problem correctly, and
gets us the information we need.

gdb: avoid double stop after failed breakpoint condition check

This commit replaces this earlier commit:

  commit 2e411b8c68eb2b035b31d5b00d940d4be1a0928b
  Date:   Fri Oct 14 14:53:15 2022 +0100

      gdb: don't always print breakpoint location after failed condition check

and is a result of feedback received here[1].

The original commit addressed a problem where, if a breakpoint
condition included an inferior function call, and if the inferior
function call failed, then GDB would announce the stop twice.  Here's
an example of GDB's output before the above commit that shows the
problem being addressed:

  (gdb) break foo if (some_func ())
  Breakpoint 1 at 0x40111e: file bpcond.c, line 11.
  (gdb) r
  Starting program: /tmp/bpcond

  Program received signal SIGSEGV, Segmentation fault.
  0x0000000000401116 in some_func () at bpcond.c:5
  5       return *p;
  Error in testing condition for breakpoint 1:
  The program being debugged stopped while in a function called from GDB.
  Evaluation of the expression containing the function
  (some_func) will be abandoned.
  When the function is done executing, GDB will silently stop.

  Breakpoint 1, 0x0000000000401116 in some_func () at bpcond.c:5
  5       return *p;
  (gdb)

The original commit addressed this issue in breakpoint.c, by spotting
that the $pc had changed while evaluating the breakpoint condition,
and inferring from this that GDB must have stopped elsewhere.

However, the way in which the original commit suppressed the second
stop announcement was to set bpstat::print to true -- this tells GDB
not to print the frame during the stop announcement, and for the CLI
this is fine, however, it was pointed out that for the MI this still
isn't really enough.  Below is an example from an MI session after the
above commit was applied, this shows the problem with the above
commit:

  -break-insert -c "cond_fail()" foo
  ^done,bkpt={number="1",type="breakpoint",disp="keep",enabled="y",addr="0x000000000040111e",func="foo",file="/tmp/mi-condbreak-fail.c",line="30",thread-groups=["i1"],cond="cond_fail()",times="0",original-location="foo"}
  (gdb)
  -exec-run
  =thread-group-started,id="i1",pid="2636270"
  =thread-created,id="1",group-id="i1"
  =library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1",ranges=[{from="0x00007ffff7fd3110",to="0x00007ffff7ff2bb4"}]
  ^running
  *running,thread-id="all"
  (gdb)
  =library-loaded,id="/lib64/libm.so.6",target-name="/lib64/libm.so.6",host-name="/lib64/libm.so.6",symbols-loaded="0",thread-group="i1",ranges=[{from="0x00007ffff7e59390",to="0x00007ffff7ef4f98"}]
  =library-loaded,id="/lib64/libc.so.6",target-name="/lib64/libc.so.6",host-name="/lib64/libc.so.6",symbols-loaded="0",thread-group="i1",ranges=[{from="0x00007ffff7ca66b0",to="0x00007ffff7df3c5f"}]
  ~"\nProgram"
  ~" received signal SIGSEGV, Segmentation fault.\n"
  ~"0x0000000000401116 in cond_fail () at /tmp/mi-condbreak-fail.c:24\n"
  ~"24\t  return *p;\t\t\t/* Crash here.  */\n"
  *stopped,reason="signal-received",signal-name="SIGSEGV",signal-meaning="Segmentation fault",frame={addr="0x0000000000401116",func="cond_fail",args=[],file="/tmp/mi-condbreak-fail.c",fullname="/tmp/mi-condbreak-fail.c",line="24",arch="i386:x86-64"},thread-id="1",stopped-threads="all",core="9"
  &"Error in testing condition for breakpoint 1:\n"
  &"The program being debugged was signaled while in a function called from GDB.\n"
  &"GDB remains in the frame where the signal was received.\n"
  &"To change this behavior use \"set unwindonsignal on\".\n"
  &"Evaluation of the expression containing the function\n"
  &"(cond_fail) will be abandoned.\n"
  &"When the function is done executing, GDB will silently stop.\n"
  =breakpoint-modified,bkpt={number="1",type="breakpoint",disp="keep",enabled="y",addr="0x000000000040111e",func="foo",file="/tmp/mi-condbreak-fail.c",fullname="/tmp/mi-condbreak-fail.c",line="30",thread-groups=["i1"],cond="cond_fail()",times="1",original-location="foo"}
  *stopped
  (gdb)

Notice that we still see two '*stopped' lines, the first includes the
full frame information, while the second has no frame information,
this is a result of bpstat::print having been set.  Ideally, the
second '*stopped' line should not be present.

By setting bpstat::print I was addressing the problem too late, this
flag really only changes how interp::on_normal_stop prints the stop
event, and interp::on_normal_stop is called (indirectly) from the
normal_stop function in infrun.c.  A better solution is to avoid
calling normal_stop at all for the stops which should not be reported
to the user, and this is what I do in this commit.

This commit has 3 parts:

  1. In breakpoint.c, revert the above commit,

  2. In fetch_inferior_event (infrun.c), capture the stop-id before
  calling handle_inferior_event.  If, after calling
  handle_inferior_event, the stop-id has changed, then this indicates
  that somewhere within handle_inferior_event, a stop was announced to
  the user.  If this is the case then GDB should not call normal_stop,
  and we should rely on whoever announced the stop to ensure that we
  are in a PROMPT_NEEDED state, which means the prompt will be
  displayed once fetch_inferior_event returns.  And,

  3. In infcall.c, do two things:

     (a) In run_inferior_call, after making the inferior call, ensure
     that either async_disable_stdin or async_enable_stdin is called
     to put the prompt state, and stdin handling into the correct
     state based on whether the inferior call completed successfully
     or not, and

     (b) In call_thread_fsm::should_stop, call async_enable_stdin
     rather than changing the prompt state directly.  This isn't
     strictly necessary, but helped me understand this code more.
     This async_enable_stdin call is only reached if normal_stop is
     not going to be called, and replaces the async_enable_stdin call
     that exists in normal_stop.  Though we could just adjust the
     prompt state if felt (to me) much easier to understand when I
     could see this call and the corresponding call in normal_stop.

With these changes in place now, when the inferior call (from the
breakpoint condition) fails, infcall.c leaves the prompt state as
PROMPT_NEEDED, and leaves stdin registered with the event loop.

Back in fetch_inferior_event GDB notices that the stop-id has changed
and so avoids calling normal_stop.

And on return from fetch_inferior_event GDB will display the prompt
and handle input from stdin.

As normal_stop is not called the MI problem is solved, and the test
added in the earlier mentioned commit still passes just fine, so the
CLI has not regressed.

[1] https://inbox.sourceware.org/gdb-patches/6fd4aa13-6003-2563-5841-e80d5a55d59e@palves.net/

Remove PEI_HEADERS define

I noticed a few files double-included libcoff.h, and digging deeper I
found that the PEI_HEADERS define is a sort of external include guard.

This patch adds include guards to the few files in include/coff that
were missing one, and then removes the PEI_HEADERS workaround and the
redundant includes.

I didn't see anything in these files that indicated that
double-inclusion would be useful, so it seems to me that this approach
is ok.

Tested by rebuilding with --enable-targets=all.

2023-08-02  Tom Tromey  <tromey@adacore.com>

* pei-x86_64.c (PEI_HEADERS): Do not define.
* pei-loongarch64.c (PEI_HEADERS): Do not define.
* pei-aarch64.c (PEI_HEADERS): Do not define.
* pe-x86_64.c (PEI_HEADERS): Do not define.
* pe-aarch64.c (PEI_HEADERS): Do not define.
* libpei.h (_LIBPEI_H): Add include guard.
* coff-x86_64.c (PEI_HEADERS): Do not check.
* coff-loongarch64.c (PEI_HEADERS): Do not check.
* coff-aarch64.c (PEI_HEADERS): Do not check.

include/ChangeLog
2023-08-02  Tom Tromey  <tromey@adacore.com>

* coff/x86_64.h (COFF_X86_64_H): Add include guard.
* coff/loongarch64.h (COFF_LOONGARCH64_H): Add include guard.
* coff/aarch64.h (COFF_AARCH64_H): Add include guard.

readelf sprintf optimisation

This replaces sprintf and strcat calls with stpcpy, and makes use of
sprintf return value rather than using strlen, for get_machine_flags.

decode_NDS32_machine_flags made use of snprintf, which is arguably the
"correct" way to do things if there can be a buffer overflow.  In this
case I don't think there can be, the buffer is 1k in size which is at
least 5 times more than needed.  What's more, snprintf returns the
count of chars that would be output given no buffer limit, which means
code like
  r += snprintf (buf + r, size - r, ...);
  r += snprintf (buf + r, size - r, ...);
is just wrong.  There needs to be a check on the return value in order
to prevent buf + r being out of bounds for the second snprintf call.

BTW, if you look closely you'll see the return value of the decode
functions is unused.  I admit to getting a little carried away with
writing "out = stpcpy (out, ...):" in each of the decode functions and
didn't notice that until get_machine_flags was trimmed down to a much
smaller size.  When I did notice, I decided it's not such a bad thing.

* readelf.c (decode_ARC_machine_flags, decode_ARM_machine_flags),
(decode_AVR_machine_flags, decode_NDS32_machine_flags),
(decode_AMDGPU_machine_flags): Use stpcpy and sprintf return
value.  Return end of string.
(decode_BLACKFIN_machine_flags, decode_FRV_machine_flags),
(decode_IA64_machine_flags, decode_LOONGARCH_machine_flags),
(decode_M68K_machine_flags, decode_MeP_machine_flags),
(decode_MIPS_machine_flags, decode_MSP430_machine_flags),
(decode_PARISC_machine_flags, decode_RISCV_machine_flags),
(decode_RL78_machine_flags, decode_RX_machine_flags),
(decode_SH_machine_flags, decode_SPARC_machine_flags),
(decode_V800_machine_flags, decode_V850_machine_flags),
(decode_Z80_machine_flags): New functions, split out from..
(get_machine_flags): ..here.  Similarly use stpcpy.

binutils sprintf optimisation

Avoid the use of sprintf with a "%s" format string, replacing with
strcpy or stpcpy.  Use sprintf return value rather than a later
strlen.  Don't use strcat where we can keep track of the end of a
string output buffer.

* dlltool.c (look_for_prog): memcpy prefix and strcpy prog_name.
* dllwrap.c (look_for_prog): Likewise.
* resrc.c (look_for_default): Likewise.  Add quotes with memmove
rather than allocating another buffer.
* size.c (size_number): Use sprintf return value.
* stabs.c (parse_stab_argtypes): Likewise.
* windmc.c (write_bin): Likewes, and use stpcpy.
* wrstabs.c: Similarly throughout.

cris: sprintf optimisation

Since I was poking at cris-dis.c to avoid the sanitizer warning,
I figure I might as well make use of stpcpy and sprintf return value
in other places in this file.

* cris-dis.c (format_hex): Use sprintf return value.
(format_reg): Use stpcpy and sprintf return, avoiding strlen.
(format_sup_reg): Likewise.

arm: sanitizer stringop-overflow

In function 'memset',
    inlined from 'create_unwind_entry' at /home/alan/src/binutils-gdb/gas/config/tc-arm.c:27881:3:
/usr/include/bits/string_fortified.h:59:10: error: '__builtin_memset' specified size between 2147483652 and 4294967295 exceeds maximum object size 2147483647 [-Werror=stringop-overflow=]
   59 |   return __builtin___memset_chk (__dest, __ch, __len,
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   60 |                                  __glibc_objsize0 (__dest));
      |                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~

* config/tc-arm.c (create_unwind_entry): Return after bad size,
and bad opcode count.