In collect_register() function of arc-linux-tdep.c, the "eret"
(exception return) register value was not being reported correctly.
This patch fixes that.

Background:
When asked for the "pc" value, we have to update the "eret" register
with GDB's STOP_PC.  The "eret" instructs the kernel code where to
jump back when an instruction has stopped due to a breakpoint.  This
is how collect_register() was doing so:

--------------8<--------------
  if (regnum == gdbarch_pc_regnum (gdbarch))
    regnum = ARC_ERET_REGNUM;
  regcache->raw_collect (regnum, buf + arc_linux_core_reg_offsets[regnum]);
-------------->8--------------

Root cause:
Although this is using the correct offset (ERET register's), it is also
changing the REGNUM itself.  Therefore, raw_collect (regnum, ...) is
not reading from "pc" anymore.

v2:
- Fix a copy/paste issue as rightfully addressed by Tom [1].

[1]
https://sourceware.org/pipermail/gdb-patches/2020-November/173208.html

gdb/ChangeLog:

	* arc-linux-tdep.c (collect_register): Populate "eret" by
	"pc" value from the regcache when asked for "pc" value.

PR rust/26799 points out that a certain test case fails with -readnow.
This happens because, with -readnow, there are no partial symtabs; but
find_symbol_at_address requires these.

This patch fixes this problem by searching all of an objfile's
compunit symtabs if it does not have partial symbols.

Note that this test will still fail with .gdb_index.  I don't think
that is readily fixable.

gdb/ChangeLog
2020-11-12  Tom Tromey  <tom@tromey.com>

	PR rust/26799:
	* symtab.c (find_symbol_at_address): Search symtabs if no psymtabs
	exist.

gdb/testsuite/ChangeLog
2020-11-12  Tom Tromey  <tom@tromey.com>

	PR rust/26799:
	* gdb.rust/traits.exp: Remove kfails.

Clang fails to compile gdb.threads/tls-so_extern_main.c, giving the
following error:

  /gdbtest/src/gdb/testsuite/gdb.threads/tls-so_extern_main.c:28:1:
    warning: non-void function does not return a value [-Wreturn-type]

This commit adds a return statement to the offending function.

gdb/testsuite/ChangeLog:

	* gdb.threads/tls-so_extern_main.c (tls_ptr): Add missing return
	statement.

	* m32r-sim.h (m32rbf_h_accum_get_handler): Always provide a
	prototype for this function.
	(m32rbf_h_accum_set_handler): Likewise.
	(m32r2f_h_accums_get_handler): Prototype.
	(m32r2f_h_accums_set_handler): Prototype.

Stop Gas from generating line info or address ranges for sections that do not contain code or are not loaded.

	PR 26850
	* dwarf2dbg.c (dwarf2_gen_line_info_1): Do not record lines in
	sections that are not executable or not loadable.
	(out_debug_line): Move warning message into dwarf2_gen_line_info_1.
	* testsuite/gas/elf/dwarf2-20.s: New test.
	* testsuite/gas/elf/dwarf2-20.d: New test driver.
	* testsuite/gas/elf/elf.exp: Run the new test.
	* testsuite/gas/elf/warn-2.s: Use the .nop directive.

GDB has two approaches to generating the target descriptions found in
gdb/features/, the whole description approach, where the XML file
contains a complete target description which is then used to generate
a single C file that builds that target description.  Or, the split
feature approach, where the XML files contain a single target feature,
each feature results in a single C file to create that one feature,
and then a manually written C file is used to build a complete target
description from individual features.

There's a Makefile, gdb/features/Makefile, which is responsible for
managing the regeneration of the C files from the XML files.

However, some of the logic that selects between the whole description
approach, or the split feature approach, is actually hard-coded into
GDB, inside target-descriptions.c:maint_print_c_tdesc_cmd we check the
path to the incoming XML file and use this to choose which type of C
file we should generate.

This commit removes this hard coding from GDB, and makes the Makefile
entirely responsible for choosing the approach.  This makes sense as
the Makefile already has the XML files partitioned based on which
approach they should use.

In order to allow this change the 'maint print c-tdesc' command is
given a new command option '-single-feature', which tells GDB which
type of C file should be created.  The makefile now supplies this flag
to GDB.

This did reveal a bug in features/Makefile, the rx.xml file was in the
wrong list, this didn't matter previously as the actual choice of
which approach to use was done in GDB.  Now the Makefile decides, so
placing each XML file in the correct list is critical.

Tested this by doing 'make GDB=/path/to/gdb clean-cfiles cfiles' to
regenerate all the C files from their XML source.  There are no
changes after this commit.

gdb/ChangeLog:

	* features/Makefile (XMLTOC): Add rx.xml.
	(FEATURE_XMLFILES): Remove rx.xml.
	(FEATURE_CFILES rule): Pass '-single-feature' flag.
	* features/rx.c: Regenerate.
	* features/rx.xml: Wrap in `target` tags, and reindent.
	* target-descriptions.c (struct maint_print_c_tdesc_options): New
	structure.
	(maint_print_c_tdesc_opt_def): New typedef.
	(maint_print_c_tdesc_opt_defs): New static global.
	(make_maint_print_c_tdesc_options_def_group): New function.
	(maint_print_c_tdesc_cmd): Make use of command line flags, only
	print single feature C file for target descriptions containing a
	single feature.
	(maint_print_c_tdesc_cmd_completer): New function.
	(_initialize_target_descriptions): Update call to register command
	completer, and include command line flag in help text.

gdb/doc/ChangeLog:

	* gdb.texinfo (Maintenance Commands): Update description of 'maint
	print c-tdesc'.

gdb/testsuite: add "breakpoint always-inserted" axis in gdb.base/continue-after-aborted-step-over.exp

The test gdb.base/continue-after-aborted-step-over.exp fails on ROCm GDB
[1] when using the unix board (when debugging a standard x86-64/Linux
program), with:

    (gdb) b *0^M
    Breakpoint 2 at 0x0^M
    Warning:^M
    Cannot insert breakpoint 2.^M
    Cannot access memory at address 0x0^M
    ^M
    (gdb) FAIL: gdb.base/continue-after-aborted-step-over.exp: displaced-stepping=off: b *0

This happens because that build of GDB defaults to "set breakpoint
always-inserted on", for reasons that are unrelevant to explain here.
As soon as the breakpoint is created, GDB tries to insert it and
(expectedly) fails.  This causes more text to be output than what the
pattern expects.

It is actually be relevant to run the test with both "set breakpoint
always-inserted" on and off.  With it on, it mimics what happens when
running in non-stop mode, with other threads running.  This is relevant
for upstream even outside of the ROCm port, so here's a patch for it.

Add this other axis and adjust the "b *0" test to handle the extra
output when it is on.

[1] https://github.com/ROCm-Developer-Tools/ROCgdb

gdb/testsuite/ChangeLog:

	* gdb.base/continue-after-aborted-step-over.exp: Add "breakpoint
	always-inserted" axis.
	(do_test): Add breakpoint_always_inserted parameter.

Change-Id: I95126cae563a0b9a72f4a99627809fc34340cd5e

Allow users to use LS64 extension with Armv8.6 architecture.

	* dwarf.c (display_debug_rnglists_list): Only bias the
	DW_RLS_offset_pair with the base address.

A recent BFD change caused a build failure for a Windows->PPC cross:

ld.exe: ../bfd/libbfd.a(coff-rs6000.o):coff-rs6000.c:(.text+0x4571): undefined reference to `getuid'
ld.exe: ../bfd/libbfd.a(coff-rs6000.o):coff-rs6000.c:(.text+0x457e): undefined reference to `getgid'

This patch fixes the problem by moving the replacement definitions of
getuid and getgid to system.h.

bfd/ChangeLog
2020-11-11  Tom Tromey  <tromey@adacore.com>

	* archive.c (getuid, getgid): Move...
	* sysdep.h (getuid, getgid): ...here.

Extends riscv_dwarf_reg_to_regnum to add the ability to convert the
DWARF register numbers for CSRs into GDB's internal numbers.

gdb/ChangeLog:

	* riscv-tdep.c (riscv_dwarf_reg_to_regnum): Decode DWARF CSR
	numbers.
	* riscv-tdep.h (RISCV_DWARF_FIRST_CSR, RISCV_DWARF_LAST_CSR): New
	enum values.

The help text for the --disable-packet option was missing one of the
possible values.

As this option is for maintainers only it is explicitly not documented
in gdb/doc/gdb.texinfo, so no update is needed there.

gdbserver/ChangeLog:

	* server.cc (gdbserver_usage): Add missing option to usage text.
	(gdbserver_show_disableable): Likewise.

This changes internalvar_name to return a const char *.

gdb/ChangeLog
2020-11-10  Tom Tromey  <tom@tromey.com>

	* value.h (internalvar_name): Update.
	* value.c (internalvar_name): Make return type const.

This changes a few spots in ax-gdb.c to use a "const char *" rather
than a non-const one.

gdb/ChangeLog
2020-11-10  Tom Tromey  <tom@tromey.com>

	* ax-gdb.c (gen_struct_elt_for_reference, gen_namespace_elt)
	(gen_maybe_namespace_elt, gen_aggregate_elt_ref, gen_expr): Use
	const.

This changes the "ptr" parameter to value_nsstring to be const.

gdb/ChangeLog
2020-11-10  Tom Tromey  <tom@tromey.com>

	* objc-lang.h (value_nsstring): Update.
	* objc-lang.c (value_nsstring): Make "ptr" const.

A recent commit caused pathstuff.cc to fail to compile on mingw, like:

../../binutils-gdb/gdbsupport/pathstuff.cc:324:1: error: no previous declaration for 'std::string find_gdb_home_config_file(const char*, _stati64*)' [-Werror=missing-declarations]

Some newly-added #includes were changing which "stat" was being seen
by the compiler.  This patch moves the includes to the header, so that
the declaration and definition now agree.

2020-11-10  Tom Tromey  <tromey@adacore.com>

	PR build/26848:
	* pathstuff.h: Move include block here...
	* pathstuff.cc: ... from here.

While working on a different bug in the Ada support, I found that the
gdb.ada/bias.exp test is slightly incorrect.  In particular, it is
using a range type, which it then overflows during an operation.

This patch changes the test so that the computed values remain in
range.

gdb/testsuite/ChangeLog
2020-11-10  Tom Tromey  <tromey@adacore.com>

	* gdb.ada/bias.exp: Update.
	* gdb.ada/bias/bias.adb (X): Change value.

The "vla_optimized_out" procedure in gdb.base/vla-optimized-out.exp
accepts a "sizeof_result" argument which is substituted into the
regular expression used to check the result of printing the sizeof
a VLA.  The -O3 test variants, however, pass a regular expression
fragment as that argument, which expands into a regular expression
that matches any result with a "6" in it.  This commit wraps the
substitution with parentheses to prevent these false matches.

gdb/testsuite/ChangeLog:

	* gdb.base/vla-optimized-out.exp (p sizeof (a)): Wrap supplied
	regexp fragment in parentheses to prevent false matching.

The function f1 in gdb.base/vla-optimized-out.c sets various
attributes to prevent its being inlined, but Clang inlines it
anyway, causing the test that uses it to fail.  This commit
adds the "weak" attribute to cause Clang to keep the function
fully out of line so the test can operate as it should.

gdb/testsuite/ChangeLog:

	* gdb.base/vla-optimized-out.c (f1): Add __attribute__ ((weak)).

Clang fails to compile gdb.cp/step-and-next-inline.cc, with the
following error:

  clang-12: error: unknown argument: '-gstatement-frontiers'
  compiler exited with status 1

This commit fixes the testcase by only passing -gstatement-frontiers
when building with GCC.  This commit also alters two checks marked as
known failures, to mark them as known failures only when built using
GCC.

gdb/testsuite/ChangeLog:

	* gdb.cp/step-and-next-inline.exp: Only require
	-gstatement-frontiers when building with GCC.
	Only setup KFAIL's for GCC issues when using
	a GCC-built executable.

	* dwarf.c (skip_attr_bytes): Correctly handle DW_FORM_ref8.
	(get_type_abbrev_from_form): Accept DW_FORM_ref8.

	* config/obj-elf (obj_elf_init_stab_section): Improve
	reproducibility for stabs debugging data format

32 bits is too big for the field.

	* vms-alpha.c (alpha_vms_write_exec): Write 16 bits to eihd.alias.

include	* opcode/pru.h: Add LMBD (left-most bit detect) opcode index
opcodes * pru-opc.c: Add opcode description for LMBD (left-most bit detect)
gas 	* testsuite/gas/pru/misc.s: Add tests for lmbd (left-most bit detect)
 	* testsuite/gas/pru/misc.d: Add tests for lmbd (left-most bit

This patch:
+ Adds new ACCDATA_EL1 (Accelerator Data) system register, see [0].
+ Adds LS64 instruction tests.
+ Update LS64 feature test with new register.
+ Fix comment for AARCH64_OPND_Rt_LS64.

    [0] https://developer.arm.com/docs/ddi0595/i/aarch64-system-registers/accdata_el1

Note: as this is register only extension we do not want to hide these
registers behind -march flag going forward (they should be enabled by
default).

Atomic 64-byte load/store instructions limit Rt register number to
values matching below condition (register <Xt> number must be even
and <= 22):

    if Rt<4:3> == '11' || Rt<0> == '1' then UNDEFINED;

This patch adds check if Rt fulfills above requirement.

For more details regarding atomic 64-byte load/store instruction for
Armv8.7 please refer to Arm A64 Instruction set documentation for
Armv8-A architecture profile, see document page 157 for load
instruction, and pages 414-418 for store instructions of [0].

    [0]: https://developer.arm.com/docs/ddi0596/i

binutils/:
	* Makefile.am (development.exp): Fix regexp.
	* Makefile.in: Regenerate.
gas/:
	* Makefile.am (development.exp): Fix regexp.
	* Makefile.in: Regenerate.
ld/:
	* Makefile.am (development.exp): Fix regexp.
	* Makefile.in: Regenerate.

	PR 26847
	* dwarf.c (read_and_display_attr_value): In wide mode, display the
	name of the form.

elfedit.c:904:15: error: 'osabi' may be used uninitialised in this function [-Werror=maybe-uninitialized]
  904 |       osabi = concat (osabi, "|", osabis[i].name, NULL);
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	* elfedit (usage): Avoid false positive "may be used uninitialised".
	Don't leak memory.

This patch fixes fails adding library dependencies for xcoff, and
improves the error message should stat fail for an archive member.
"tmpdir/artest.a: File not found" is plainly wrong.

Fixes these fails:
powerpc-aix5.1  +FAIL: ar adding library dependencies
powerpc-aix5.2  +FAIL: ar adding library dependencies
rs6000-aix4.3.3  +FAIL: ar adding library dependencies
rs6000-aix5.1  +FAIL: ar adding library dependencies
rs6000-aix5.2  +FAIL: ar adding library dependencies

	* archive.c (bfd_ar_hdr_from_filesystem): Use bfd_set_input_error
	when stat of archive member fails.
	* coff-rs6000.c (xcoff_write_archive_contents_old),
	(xcoff_write_archive_contents_big): Likewise, and handle in-memory
	bfd.

This feature doesn't actually require plugin support, that was a
mistake in the previous patch.  Fixes these fails:

hppa-hp-hpux10  +FAIL: ar adding library dependencies
i386-bsd  +FAIL: ar adding library dependencies
i386-msdos  +FAIL: ar adding library dependencies
ns32k-netbsd  +FAIL: ar adding library dependencies
ns32k-pc532-mach  +FAIL: ar adding library dependencies
pdp11-dec-aout  +FAIL: ar adding library dependencies

	* ar.c (main): Use plugin_target rather than "target" when
	resetting libdeps_bfd target.

Originally, if the -mabi option isn't set, then assembler will set the
abi according to the architecture string in the riscv_after_parse_args.
But we should also check and reset the abi later since the architecture
string may be reset by the elf attributes.  Therefore, set the abi to
the elf_flags in the riscv_after_parse_args seems too early.  Besides,
we have to set the abi_xlen before assembling any instruction, so it
should be safe to call riscv_set_abi_by_arch at the place that we set
start_assemble to TRUE.  However, one minor case is that we won't call
the md_assemble when we are assembling an file without any instruction.
It seems that we still need to set the abi in riscv_elf_final_processing,
to make sure that abi can be updated according to the elf arch attributes.

For the rv32i and most elf toolchains, this patch can fix the mis-matched
ABI errors for Run pr26391-5 and Run pr26391-6 testcases.  Besides, it
also correct the elf header flags of the output objects.  Consider the
new testcases, mabi-fail-02 and mabi-noabi-attr-[01|02|03], they are
failed before applying this patch.

But I still get the mis-matched ABI errors for the following toolchains
when runnung the riscv-gnu-toolchain regressions,

newlib-rv32imafc-ilp32f-[medlow|medany]
linux-rv32imac-ilp32-[medlow|medany]
linux-rv32imafdc-ilp32-[medlow|medany}
linux-rv64imac-lp64-[medlow|medany]
linux-rv64imafdc-lp64-[medlow|medany}

For the newlib-rv32imafc-ilp32f, although we try to choose the abi
according to the elf attributes, we will use FLOAT_ABI_SOFT rather
than the FLOAT_ABI_SINGLE for the assmebly file wihtout setting the
-mabi, but compiler will set the abi to FLOAT_ABI_SINGLE for the
C files.

As for the linux toolchains, we also get fails for Run pr26391-5 and
Run pr26391-6 testcases.  Since the linux toolchain won't generate elf
attributes to correct the ISA, and the --with-arch configure option
isn't set, assembler will try to set the default arch to rv[32|64]g,
which means the FLOAT_ABI_DOUBLE will be choosed, and may be conflict
with the abi set by the toolchain.

Therefore, I would suggest that it's is more safe to set the --with-arch
when building binutils, but it may break some testcases.  For example,
ld-scripts/fill and ld-scripts/empty-address-2 may be broken when c-ext
is set.  We might insert R_RISCV_ALIGN to make sure the 4-byte alignment,
but the dump result will be a bit different from what the testcase expected.

However, this patch only fix the problem - the abi, elf_flags and the
instruction, which is generated according to the abi_xlen, are all fixed
once the elf attributes are set for most elf toolchains. Other mis-matched
ABI problems should be fixed when we always build the binutils with the
--with-arch= configure option.

	gas/
	* config/tc-riscv.c (explicit_mabi): New boolean to indicate if
	the -mabi= option is explictly set.
	(md_parse_option): Set explicit_mabi to TRUE if -mabi is set.
	(riscv_set_abi_by_arch): New function.  If the -mabi option isn't
	set, then we set the abi according to the architecture string.
	Otherwise, check if there are conflicts between architecture
	and abi setting.
	(riscv_after_parse_args): Move the abi setting to md_assemble nad
	riscv_elf_final_processing.
	(md_assemble): Call the riscv_set_abi_by_arch when we set the
	start_assemble to TRUE.
	(riscv_elf_final_processing): Likewise, in case the file without
	any instruction.

	* testsuite/gas/riscv/mabi-attr-01.s: New testcase.
	* testsuite/gas/riscv/mabi-attr-02.s: Likewise.
	* testsuite/gas/riscv/mabi-attr-03.s: Likewise.
	* testsuite/gas/riscv/mabi-fail-01.d: Likewise.
	* testsuite/gas/riscv/mabi-fail-01.l: Likewise.
	* testsuite/gas/riscv/mabi-fail-02.d: Likewise.
	* testsuite/gas/riscv/mabi-fail-02.l: Likewise.
	* testsuite/gas/riscv/mabi-noabi-attr-01a.d: Likewise.
	* testsuite/gas/riscv/mabi-noabi-attr-01b.d: Likewise.
	* testsuite/gas/riscv/mabi-noabi-attr-02a.d: Likewise.
	* testsuite/gas/riscv/mabi-noabi-attr-02b.d: Likewise.
	* testsuite/gas/riscv/mabi-noabi-attr-03a.d: Likewise.
	* testsuite/gas/riscv/mabi-noabi-attr-03b.d: Likewise.
	* testsuite/gas/riscv/mabi-noabi-march-01.d: Likewise.
	* testsuite/gas/riscv/mabi-noabi-march-02.d: Likewise.
	* testsuite/gas/riscv/mabi-noabi-march-03.d: Likewise.

class Plugin_manager has

  // A pointer to the current plugin.  Used while loading plugins.
  Plugin_list::iterator current_;

The same iterator is shared by all threads. It is OK to use it to load
plugins since only one thread loads plugins.  Avoid sharing Plugin_list
iterator in all other cases.

	PR gold/26200
	* plugin.cc (Plugin_manager::claim_file): Don't share Plugin_list
	iterator.
	(Plugin_manager::all_symbols_read): Likewise.
	(Plugin_manager::cleanup): Likewise.