396 Commits

Author SHA1 Message Date
6aa4f97c2b gdb: print backtrace on fatal SIGSEGV
This commit adds a new maintenance feature, the ability to print
a (limited) backtrace if GDB dies due to a fatal signal.

The backtrace is produced using the backtrace and backtrace_symbols_fd
functions which are declared in the execinfo.h header, and both of
which are async signal safe.  A configure check has been added to
check for these features, if they are not available then the new code
is not compiled into GDB and the backtrace will not be printed.

The motivation for this new feature is to aid in debugging GDB in
situations where GDB has crashed at a users site, but the user is
reluctant to share core files, possibly due to concerns about what
might be in the memory image within the core file.  Such a user might
be happy to share a simple backtrace that was written to stderr.

The production of the backtrace is on by default, but can switched off
using the new commands:

  maintenance set backtrace-on-fatal-signal on|off
  maintenance show backtrace-on-fatal-signal

Right now, I have hooked this feature in to GDB's existing handling of
SIGSEGV only, but this will be extended to more signals in a later
commit.

One additional change I have made in this commit is that, when we
decide GDB should terminate due to the fatal signal, we now
raise the same fatal signal rather than raising SIGABRT.

Currently, this is only effecting our handling of SIGSEGV.  So,
previously, if GDB hit a SEGV then we would terminate GDB with a
SIGABRT.  After this commit we will terminate GDB with a SIGSEGV.

This feels like an improvement to me, we should still get a core dump,
but in many shells, the user will see a more specific message once GDB
exits, in bash for example "Segmentation fault" rather than "Aborted".

Finally then, here is an example of the output a user would see if GDB
should hit an internal SIGSEGV:

  Fatal signal: Segmentation fault
  ----- Backtrace -----
  ./gdb/gdb[0x8078e6]
  ./gdb/gdb[0x807b20]
  /lib64/libpthread.so.0(+0x14b20)[0x7f6648c92b20]
  /lib64/libc.so.6(__poll+0x4f)[0x7f66484d3a5f]
  ./gdb/gdb[0x1540f4c]
  ./gdb/gdb[0x154034a]
  ./gdb/gdb[0x9b002d]
  ./gdb/gdb[0x9b014d]
  ./gdb/gdb[0x9b1aa6]
  ./gdb/gdb[0x9b1b0c]
  ./gdb/gdb[0x41756d]
  /lib64/libc.so.6(__libc_start_main+0xf3)[0x7f66484041a3]
  ./gdb/gdb[0x41746e]
  ---------------------
  A fatal error internal to GDB has been detected, further
  debugging is not possible.  GDB will now terminate.

  This is a bug, please report it.  For instructions, see:
  <https://www.gnu.org/software/gdb/bugs/>.

  Segmentation fault (core dumped)

It is disappointing that backtrace_symbols_fd does not actually map
the addresses back to symbols, this appears, in part, to be due to GDB
not being built with -rdynamic as the manual page for
backtrace_symbols_fd suggests, however, even when I do add -rdynamic
to the build of GDB I only see symbols for some addresses.

We could potentially look at alternative libraries to provide the
backtrace (e.g. libunwind) however, the solution presented here, which
is available as part of glibc is probably a good baseline from which
we might improve things in future.
2021-08-11 12:35:14 +01:00
a100a94530 gdb/testsuite: restore configure script
Commit f99d1d37496f ("Remove gdb/testsuite/configure") removed
gdb/testsuite/configure, as anything gdb/testsuite/configure did could
be done by gdb/configure.

There is however one use case that popped up when this changed
propagated to downstream consumers, to run the testsuite on an already
built GDB.  In the workflow of ROCm-GDB at AMD, a GDB package is built
in a CI job.  This GDB package is then tested on different machines /
hardware configurations as part of other CI jobs.  To achieve this,
those CI jobs only configure the testsuite directory and run "make
check" with an appropriate board file.

In light of this use case, the way I see it is that gdb/testsuite could
be considered its own project.  It could be stored in a completely
different repo if we want to, it just happens to be stored inside gdb/.

Since the only downside of having gdb/testsuite/configure is that it
takes a few more seconds to run, but on the other hand it's quite useful
for some people, I propose re-adding it.

In a sense, this is revert of f99d1d37496f, but it's not a direct
git-revert, as some things have changed since.

gdb/ChangeLog:

	* configure.ac: Remove things that were moved from
	testsuite/configure.ac.
	* configure: Re-generate.

gdb/testsuite/ChangeLog:

	* configure.ac: Restore.
	* configure: Re-generate.
	* aclocal.m4: Re-generate.
	* Makefile.in (distclean): Add config.status.
	(Makefile): Adjust paths.
	(lib/pdtrace): Adjust paths.
	(config.status): Add.

Change-Id: Ic38c79485e1835712d9c99649c9dfb59667254f1
2021-07-06 14:53:27 -04:00
7e3941ac06 gdb/gdbserver: switch to AC_CONFIG_MACRO_DIRS
These dirs don't use automake, so use AC_CONFIG_MACRO_DIRS to specify
../config as a search dir for m4 macros.  This allows removal of a lot
of hand-written m4_include's from acinclude.m4 files, and simplifies
use of `aclocal` or `autoreconf` as manual -I is not needed.
2021-06-19 23:06:01 -04:00
09db4332c6 fbsd nat: Disable address space randomization when requested.
Use procctl(2) with PROC_ASLR_CTL to disable address space
randomization in the current gdb process before forking a child
process for a new inferior when address space randomization is
disabled.

gdb/ChangeLog:

	* configure.ac: Check for <sys/procctl.h>.
	* config.in, configure: Regenerate.
	* fbsd-nat.c: Include <sys/procctl.h> if present.
	[PROC_ASLR_CTL] (maybe_disable_address_space_randomization): New.
	(fbsd_nat_target::create_inferior)
	(fbsd_nat_target::supports_disable_randomization): New.
	* fbsd-nat.h (fbsd_nat_target::create_inferior)
	(fbsd_nat_target::supports_disable_randomization): New.
2021-06-14 14:55:48 -07:00
b316465fab Use ACX_NONCANONICAL_TARGET in gdb/configure
Shahab Vahedi pointed out that the patch to remove
gdb/testsuite/configure regressed the site.exp creation a bit -- it
left an unresolved configure substitution.  Andrew Burgess pointed out
that the patch removed the call to ACX_NONCANONICAL_TARGET, which
caused this problem.

This patch adds ACX_NONCANONICAL_TARGET to gdb's configure, and fixes
the bug.

gdb/ChangeLog
2021-06-05  Tom Tromey  <tromey@adacore.com>

	* configure: Rebuild.
	* configure.ac: Add ACX_NONCANONICAL_TARGET.
2021-06-05 08:47:46 -06:00
ba56237dab Clean up gdb's --enable-shared
The old testsuite configure did not use AS_HELP_STRING, and it had a
typo in the help for --enable-shared.  This patch fixes these
problems.

gdb/ChangeLog
2021-06-01  Tom Tromey  <tromey@adacore.com>

	* configure: Rebuild.
	* configure.ac: Use AS_HELP_STRING for enable-shared.  Fix typo.
2021-06-01 08:11:31 -06:00
f99d1d3749 Remove gdb/testsuite/configure
I didn't see a strong reason to have a separate configure script in
gdb/testsuite, so this patch removes it.  The few relevant configury
bits are moved into gdb's configure script.  Some of the old
testsuite/configure script (e.g., the header check) is dead code.

This also adds a Makefile rule to rebuild lib/pdtrace.  This was
missing from the old code.

'read1' is now a dependency of check-read1, rather than extra code at
configure time.

Finally, the old "ENABLE_LIBCTF" subst in gdb/configure was not used;
nor was the variable defined, so this was always empty.  However, the
lower-case variant was used by the testsuite, so this patch renames
the subst.

gdb/ChangeLog
2021-06-01  Tom Tromey  <tromey@adacore.com>

	* configure.ac: Copy some code from testsuite/configure.ac.
	(enable_libctf): Subst this, not ENABLE_LIBCTF.
	* configure: Rebuild.

gdb/testsuite/ChangeLog
2021-06-01  Tom Tromey  <tromey@adacore.com>

	* aclocal.m4, configure.ac, configure: Remove.
	* Makefile.in (EXTRA_RULES): Remove.
	($(abs_builddir)/site.exp site.exp): Don't depend on
	config.status.
	(distclean maintainer-clean realclean, Makefile): Update.
	(config.status): Remove target.
	(lib/pdtrace): New target.
	(all): Don't depend on EXTRA_RULES.
	(check-read1): Depend on read1.so, expect-read1.
2021-06-01 08:11:30 -06:00
ff50752029 [gdb/build] Hardcode --with-included-regex
Currently gdb has a configure option:
...
$ ./src/gdb/configure --help
  ...
  --without-included-regex
                          don't use included regex; this is the default on
                          systems with version 2 of the GNU C library (use
                          with caution on other system)
...

The configure option controls config.h macro USE_INCLUDED_REGEX, which is
used in gdb/gdb_regex.h to choose between:
- using regex from libiberty (which is included in the binutils-gdb.git repo,
  hence the 'included' in USE_INCLUDED_REGEX), or
- using regex.h.

In the former case, the symbol regcomp is remapped to a symbol xregcomp, which
is then provided by libiberty.

In the latter case, the symbol regcomp is resolved at runtime, usually binding
to libc.  However, there is no mechanism in place to enforce this.

PR27681 is an example of where that causes problems.  On openSUSE Tumbleweed,
the ncurses package got the --with-pcre2 configure switch enabled, and solved
the resulting dependencies using:
...
 $ cat /usr/lib64/libncursesw.so
 /* GNU ld script */
-INPUT(/lib64/libncursesw.so.6 AS_NEEDED(-ltinfo -ldl))
+INPUT(/lib64/libncursesw.so.6 AS_NEEDED(-ltinfo -ldl -lpcre2-posix -lpcre2-8))
...

This lead to regcomp being bound to libpcre2-posix instead of libc.

This causes problems in several ways:
- by compiling using regex.h, we've already chosen a specific regex_t
  implementation, and the one from pcre2-posix is not the same.
- in gdb_regex.c we use GNU regex function re_search, which pcre2-posix
  doesn't provide, so while regcomp binds to pcre2-posix, re_search binds to
  libc.

A note on the latter: it's actually a bug to compile a regex using regcomp and
then pass it to re_search.  The GNU regex interface requires one to use
re_compile_pattern or re_compile_fastmap.  But as long we're using one of the
GNU regex incarnations in gnulib, glibc or libiberty, we get away with this.

The PR could be fixed by adding -lc in a specific position in the link line,
to force regcomp to be bound to glibc.  But this solution was considered
in the discussion in the PR as being brittle, and possibly causing problems
elsewhere.

Another solution offered was to restrict regex usage to posix, and no longer
use the GNU regex API.  This however could mean having to reproduce some of
that functionality locally, which would mean maintaining the same
functionality in more than one place.

The solution chosen here, is to hardcode --with-included-regex, that is, using
libiberty.

The option of using glibc for regex was introduced because glibc became the
authorative source for GNU regex, so it offered the possibility to link
against a more up-to-date regex version.

In that aspect, this patch is a step back.  But we have the option of using a
more up-to-date regex version as a follow-up step: by using the regex from
gnulib.

Tested on x86_64-linux.

gdb/ChangeLog:

2021-04-21  Tom de Vries  <tdevries@suse.de>

	PR build/27681
	* configure.ac: Remove --without-included-regex/--with-included-regex.
	* config.in: Regenerate.
	* configure: Regenerate.
	* gdb_regex.h: Assume USE_INCLUDED_REGEX is defined.
2021-04-21 21:54:03 +02:00
92e4e97a9f gdb: process early initialization files and command line options
Adds the ability to process commands at a new phase during GDB's
startup.  This phase is earlier than the current initialisation file
processing, before GDB has produced any output.

The number of commands that can be processed at this early stage will
be limited, and it is expected that the only commands that would be
processed at this stage will relate to some of the fundamentals of how
GDB starts up.

Currently the only commands that it makes sense to add to this early
initialization file are those like 'set style version ....' as the
version string is displayed during startup before the standard
initialization files are parsed.  As such this commit fully resolved
bug cli/25956.

This commit adds a mechanism to execute these early initialization
files from a users HOME directory, as well as some corresponding
command line flags for GDB.

The early initialization files that GDB will currently check for are
~/.config/gdb/gdbearlyinit (on Linux like systems) or ~/.gdbearlyinit
if the former is not found.

The output of 'gdb --help' has been extended to include a list of the
early initialization files being processed.

gdb/ChangeLog:

	PR cli/25956
	* NEWS: Mention new early init files and command line options.
	* config.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Define GDBEARLYINIT.
	* main.c (get_earlyinit_files): New function.
	(enum cmdarg_kind): Add CMDARG_EARLYINIT_FILE and
	CMDARG_EARLYINIT_COMMAND.
	(captured_main_1): Add support for new command line flags, and for
	processing startup files.
	(print_gdb_help): Include startup files in the output.

gdb/doc/ChangeLog:

	PR cli/25956
	* gdb.texinfo (File Options): Mention new command line options.
	(Startup): Discuss when early init files are processed.
	(Initialization Files): Add description of early init files.
	(Output Styling): Update description of 'version' style.
	(gdb man): Mention early init files.

gdb/testsuite/ChangeLog:

	PR cli/25956
	* gdb.base/early-init-file.c: New file.
	* gdb.base/early-init-file.exp: New file.
	* lib/gdb-utils.exp (style): Handle style 'none'.
2021-04-15 10:34:09 +01:00
fb8f3fc0c3 gdb/riscv: introduce bare metal core dump support
This commit adds the ability for bare metal RISC-V target to generate
core files from within GDB.

The intended use case is that a user will connect to a remote bare
metal target, debug up to some error condition, then generate a core
file in the normal way using:

  (gdb) generate-core-file

This core file can then be used to revisit the state of the remote
target without having to reconnect to the remote target.

The core file creation code is split between two new files.  In
elf-none-tdep.c is code for any architecture with the none
ABI (i.e. bare metal) when the BFD library is built with ELF support.

In riscv-none-tdep.c are the RISC-V specific parts.  This is where the
regset and regcache_map_entry structures are defined that control how
registers are laid out in the core file.  As this file could (in
theory at least) be used for a non-ELF bare metal RISC-V target, the
calls into elf-none-tdep.c are guarded with '#ifdef HAVE_ELF'.

Currently for RISC-V only the x-regs and f-regs (if present) are
written out.  In future commits I plan to add support for writing out
the RISC-V CSRs.

The core dump format is based around generating an ELF containing
sections for the writable regions of memory that a user could be
using.  Which regions are dumped rely on GDB's existing common core
dumping code, GDB will attempt to figure out the stack and heap as
well as copying out writable data sections as identified by the
original ELF.

Register information is added to the core dump using notes, just as it
is for Linux of FreeBSD core dumps.  The note types used consist of
the 3 basic types you would expect in a OS based core dump,
NT_PRPSINFO, NT_PRSTATUS, NT_FPREGSET.

The layout of these notes differs slightly (due to field sizes)
between RV32 and RV64.  Below I describe the data layout for each
note.  In all cases, all padding fields should be set to zero.

Note NT_PRPSINFO is optional.  Its data layout is:

  struct prpsinfo32_t		/* For RV32.  */
  {
    uint8_t padding[32];
    char fname[16];
    char psargs[80];
  }

  struct prpsinfo64_t		/* For RV64.  */
  {
    uint8_t padding[40];
    char fname[16];
    char psargs[80];
  }

Field 'fname' - null terminated string consisting of the basename of
    (up to the fist 15 characters of) the executable.  Any additional
    space should be set to zero.  If there's no executable name then
    this field can be set to all zero.

Field 'psargs' - a null terminated string up to 80 characters in
    length.  Any additional space should be filled with zero.  This
    field contains the full executable path and any arguments passed
    to the executable.  If there's nothing sensible to write in this
    field then fill it with zero.

Note NT_PRSTATUS is required, its data layout is:

  struct prstatus32_t		/* For RV32.  */
  {
    uint8_t padding_1[12];
    uint16_t sig;
    uint8_t padding_2[10];
    uint32_t thread_id;
    uint8_t padding_3[44];
    uint32_t x_regs[32];
    uint8_t padding_4[4];
  }

  struct prstatus64_t		/* For RV64.  */
  {
    uint8_t padding_1[12];
    uint16_t sig;
    uint8_t padding_2[18];
    uint32_t thread_id;
    uint8_t padding_3[76];
    uint64_t x_regs[32];
    uint8_t padding_4[4];
  }

Field 'sig' - the signal that stopped this thread.  It's implementation
    defined what this field actually means.  Within GDB this will be
    the signal number that the remote target reports as the stop
    reason for this thread.

Field 'thread_is' - the thread id for this thread.  It's implementation
    defined what this field actually means.  Within GDB this will be
    thread thread-id that is assigned to each remote thread.

Field 'x_regs' - at index 0 we store the program counter, and at
    indices 1 to 31 we store x-registers 1 to 31.  x-register 0 is not
    stored, its value is always zero anyway.

Note NT_FPREGSET is optional, its data layout is:

  fpregset32_t			/* For targets with 'F' extension.  */
  {
    uint32_t f_regs[32];
    uint32_t fcsr;
  }

  fpregset64_t			/* For targets with 'D' extension .  */
  {
    uint64_t f_regs[32];
    uint32_t fcsr;
  }

Field 'f_regs' - stores f-registers 0 to 31.

Field 'fcsr' - stores the fcsr CSR register, and is always 4-bytes.

The rules for ordering the notes is the same as for Linux.  The
NT_PRSTATUS note must come before any other notes about additional
register sets.  And for multi-threaded targets all registers for a
single thread should be grouped together.  This is because only
NT_PRSTATUS includes a thread-id, all additional register notes after
a NT_PRSTATUS are assumed to belong to the same thread until a
different NT_PRSTATUS is seen.

gdb/ChangeLog:

	* Makefile.in (ALL_TARGET_OBS): Add riscv-none-tdep.o.
	(ALLDEPFILES): Add riscv-none-tdep.c.
	* configure: Regenerate.
	* configure.ac (CONFIG_OBS): Add elf-none-tdep.o when BFD has ELF
	support.
	* configure.tgt (riscv*-*-*): Include riscv-none-tdep.c.
	* elf-none-tdep.c: New file.
	* elf-none-tdep.h: New file.
	* riscv-none-tdep.c: New file.
2021-03-05 17:21:41 +00:00
f3a5df7bd6 gdb: unify parts of the Linux and FreeBSD core dumping code
While reviewing the Linux and FreeBSD core dumping code within GDB for
another patch series, I noticed that the code that collects the
registers for each thread and writes these into ELF note format is
basically identical between Linux and FreeBSD.

This commit merges this code and moves it into a new file gcore-elf.c.

The function find_signalled_thread is moved from linux-tdep.c to
gcore.c despite not being shared.  A later commit will make use of
this function.

I did merge, and then revert a previous version of this patch (commit
82a1fd3a4935 for the original patch and 03642b7189bc for the revert).
The problem with the original patch is that it introduced a
unconditional dependency between GDB and some ELF specific functions
in the BFD library, e.g. elfcore_write_prstatus and
elfcore_write_register_note.  It was pointed out in this mailing list
post:

  https://sourceware.org/pipermail/gdb-patches/2021-February/175750.html

that this change was breaking any build of GDB for non-ELF targets.
To confirm this breakage, and to test this new version of GDB I
configured and built for the target x86_64-apple-darwin20.3.0.

Where the previous version of this patch placed all of the common code
into gcore.c, which is included in all builds of GDB, this new patch
only places non-ELF specific generic code (i.e. find_signalled_thread)
into gcore.c, the ELF specific code is put into the new gcore-elf.c
file, which is only included in GDB if BFD has ELF support.

The contents of gcore-elf.c are referenced unconditionally from
linux-tdep.c and fbsd-tdep.c, this is fine, we previously always
assumed that these two targets required ELF support, and we continue
to make that assumption after this patch; nothing has changed there.

With my previous version of this patch the darwin target mentioned
above failed to build, but with the new version, the target builds
fine.

There are a couple of minor changes to the FreeBSD target after this
commit, but I believe that these are changes for the better:

(1) For FreeBSD we always used to record the thread-id in the core
file by using ptid_t.lwp ().  In contrast the Linux code did this:

    /* For remote targets the LWP may not be available, so use the TID.  */
    long lwp = ptid.lwp ();
    if (lwp == 0)
      lwp = ptid.tid ();

Both target now do this:

    /* The LWP is often not available for bare metal target, in which case
       use the tid instead.  */
    if (ptid.lwp_p ())
      lwp = ptid.lwp ();
    else
      lwp = ptid.tid ();

Which is equivalent for Linux, but is a change for FreeBSD.  I think
that all this means is that in some cases where GDB might have
previously recorded a thread-id of 0 for each thread, we might now get
something more useful.

(2) When collecting the registers for Linux we collected into a zero
initialised buffer.  By contrast on FreeBSD the buffer is left
uninitialised.  In the new code the buffer is always zero initialised.
I suspect once the registers are copied into the buffer there's
probably no gaps left so this makes no difference, but if it does then
using zeros rather than random bits of GDB's memory is probably a good
thing.

Otherwise, there should be no other user visible changes after this
commit.

Tested this on x86-64/GNU-Linux and x86-64/FreeBSD-12.2 with no
regressions.

gdb/ChangeLog:

	* Makefile.in (SFILES): Add gcore-elf.c.
	(HFILES_NO_SRCDIR): Add gcore-elf.h
	* configure: Regenerate.
	* configure.ac: Add gcore-elf.o to CONFIG_OBS if we have ELF
	support.
	* fbsd-tdep.c: Add 'gcore-elf.h' include.
	(struct fbsd_collect_regset_section_cb_data): Delete.
	(fbsd_collect_regset_section_cb): Delete.
	(fbsd_collect_thread_registers): Delete.
	(struct fbsd_corefile_thread_data): Delete.
	(fbsd_corefile_thread): Delete.
	(fbsd_make_corefile_notes): Call
	gcore_elf_build_thread_register_notes instead of the now deleted
	FreeBSD code.
	* gcore-elf.c: New file, the content was moved here from
	linux-tdep.c, functions were renamed and given minor cleanup.
	* gcore-elf.h: New file.
	* gcore.c (gcore_find_signalled_thread): Moved here from
	linux-tdep.c and given a new name.  Minor cleanups.
	* gcore.h (gcore_find_signalled_thread): Declare.
	* linux-tdep.c: Add 'gcore.h' and 'gcore-elf.h' includes.
	(struct linux_collect_regset_section_cb_data): Delete.
	(linux_collect_regset_section_cb): Delete.
	(linux_collect_thread_registers): Delete.
	(linux_corefile_thread): Call
	gcore_elf_build_thread_register_notes.
	(find_signalled_thread): Delete.
	(linux_make_corefile_notes): Call gcore_find_signalled_thread.
2021-03-05 17:21:40 +00:00
3666a04883 Update copyright year range in all GDB files
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...

gdb/ChangeLog

        Update copyright year range in copyright header of all GDB files.
2021-01-01 12:12:21 +04:00
0455b7d325 Warn about static libs vs. source-highlight only when necessary
Avoid the error message when source-highlight is actually available.

2020-12-19  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	* configure.ac: Move the static libs vs. source-highlight
	error message to a better place.
	* configure: Regenerate.
2020-12-19 09:21:07 +01:00
1b4ac058f7 gdb: Make GMP a required dependency for building GDB
This commit modifies gdb's configure script to trigger an error
if we cannot find a usable libgmp.

For the record, making this a requirement was discussed in March 2018:
https://sourceware.org/pipermail/gdb-patches/2018-March/147373.html

gdb/ChangeLog:

        * configure.ac: Generate an error if a usable GMP library
        could not be found.
        * configure: Regenerate.
2020-11-15 03:08:40 -05:00
2c947d9bc2 gdb/configure: Add --with-libgmp-prefix option
This patch allows a user to tell gdb's configure script where
his GMP library is installed.

gdb/ChangeLog:

        * configure.ac: Add support for --with-libgmp-prefix.
        * Makefile.in (LIBGMP): New variable.
        (CLIBS): Include $(LIBGMP).
        * configure, config.in: Regenerate
2020-11-15 03:07:45 -05:00
3fed4c0b7a gdb: better static python detection in configure machinery
In python 3, itertools is a builtin module, so whether or not the
python you link against is a shared or a static one, importing it
works.

Change the import test to use ctypes which is a dynamic module in both
python 2 and 3.

gdb/ChangeLog:

	PR python/26832
	* configure: Regenerate.
	* configure.ac: Check for python modules ctypes instead of
	itertools.
2020-11-06 18:01:47 +00:00
5593a99a95 gdb: modernize configure.ac
Run autoupdate on configure.ac and adjust the indentation of the result
for better readability.  This removes a bunch of warnings when running
`autoreconf -vf -Wall`.  The changes are:

    * Replace AC_INIT with AC_INIT and no arguments plus
      AC_CONFIG_SRCDIR.
    * Replace AC_ERROR with AC_MSG_ERROR.
    * Replace AC_TRY_LINK with AC_LINK_IFELSE.
    * Replace AC_TRY_COMPILE with AC_COMPILE_IFELSE.
    * Replace AC_HELP_STRING with AS_HELP_STRING.

autoupdate erroneously tries to replace AC_C_LONG_DOUBLE in a comment,
which I reverted manually.

All the changes in the generated configure file are insignificant
whitespaces changes.

gdb/ChangeLog:

	* configure.ac: Modernize.
	* configure: Re-generate.

Change-Id: Ie3a1409c8032a36a6383da964286a46ece9b546e
2020-10-31 08:30:58 -04:00
e41fda1d5f gdb: use AC_PROG_CC_STDC instead of AM_PROG_CC_STDC
`autoconf -Wall` notes that AM_PROG_CC_STDC is obsolete:
Fixes this autoconf warning:

    configure.ac:40: warning: 'AM_PROG_CC_STDC': this macro is obsolete.
    configure.ac:40: You should simply use the 'AC_PROG_CC' macro instead.
    configure.ac:40: Also, your code should no longer depend upon 'am_cv_prog_cc_stdc',
    configure.ac:40: but upon 'ac_cv_prog_cc_stdc'.
    aclocal.m4:770: AM_PROG_CC_STDC is expanded from...
    configure.ac:40: the top level

Since we build with a C++ compiler now, I don't think this is relevant.
If you look at the messages removed from gdbsupport/aclocal.m4, it says
that this functionality is now integrated in AC_PROG_CC, which we
already call.  So it might not even make a difference.

We had a local version of AM_PROG_CC_STDC, in gdb/acinclude.m4 (only
used by gdb/configure.ac), remove it.

gdb/ChangeLog:

	* acinclude.m4 (AM_PROG_CC_STDC): Remove.
	* configure: Re-generate.
	* configure.ac: Remove AM_PROG_CC_STDC.

gdbsupport/ChangeLog:

	* aclocal.m4: Re-generate.
	* configure: Re-generate.
	* configure.ac: Remove AM_PROG_CC_STDC.

Change-Id: Ic824393598805d4f78cda9d119f8af46096e9c73
2020-10-31 08:30:57 -04:00
91e1a0ed09 gdb, gdbserver, gdbsupport: use AC_CANONICAL_{BUILD,HOST,TARGET} instead of AC_CANONICAL_SYSTEM
`autoreconf -Wall` notes that AC_CANONICAL_SYSTEM is obsolete:

    configure.ac:36: warning: The macro `AC_CANONICAL_SYSTEM' is obsolete.

Replace it by AC_CANONICAL_BUILD, AC_CANONICAL_HOST and
AC_CANONICAL_TARGET in configure.ac files in gdb, gdbserver and
gdbsupport.  All three macros may not be needed everywhere, but it is
hard to completely audit the configure files to see which are required,
so I think it's better (and that there's no downside) to just call all
three.

gdb/ChangeLog:

	* configure.ac: Use AC_CANONICAL_{BUILD,HOST,TARGET} instead of
	AC_CANONICAL_SYSTEM.
	* configure: Re-generate.

gdbserver/ChangeLog:

	* configure.ac: Use AC_CANONICAL_{BUILD,HOST,TARGET} instead of
	AC_CANONICAL_SYSTEM.
	* configure: Re-generate.

gdbsupport/ChangeLog:

	* configure.ac: Use AC_CANONICAL_{BUILD,HOST,TARGET} instead of
	AC_CANONICAL_SYSTEM.
	* configure: Re-generate.

Change-Id: Ifd0e21f1e478634e768b5de1b8ee06a7f690d863
2020-10-31 08:30:57 -04:00
e911c6663b Require kinfo_get_file and kinfo_get_vmmap for FreeBSD hosts.
FreeBSD systems have provided these functions in libutil since 7.1
release.  The most recent release without support is 6.4 released in
November of 2008.

This also requires libutil-freebsd on GNU/kFreeBSD systems.  I assume
that those systems have supported kinfo_get_file and kinfo_get_vmmap
over a similar timeframe.

gdb/ChangeLog:

	* configure.ac: Remove check for kinfo_getvmmap().
	* configure, config.in: Regenerate.
	* fbsd-nat.c (fbsd_read_mapping): Remove
	(fbsd_nat_target::find_memory_regions): Remove the procfs version.
	(fbsd_nat_target::info_proc): Assume kinfo_getfile() and
	kinfo_get_vmmap() are always present.

gdbsupport/ChangeLog:

	* common.m4 (GDB_AC_COMMON): Refactor checks for kinfo_getfile().
	* configure, config.in: Regenerate.
2020-09-16 11:40:05 -07:00
95420d3027 [gdb/build] Fix typo sys/sockets.h -> sys/socket.h
I'm running into a build breaker:
...
src/gdb/ser-tcp.c:65:13: error: conflicting declaration ‘typedef int
socklen_t’
   65 | typedef int socklen_t;
      |             ^~~~~~~~~
In file included from ../gnulib/import/unistd.h:40,
                 from
/home/vries/gdb_versions/devel/src/gdb/../gnulib/import/pathmax.h:42,
                 from
/home/vries/gdb_versions/devel/src/gdb/../gdbsupport/common-defs.h:120,
                 from src/gdb/defs.h:28,
                 from src/gdb/ser-tcp.c:20:
/usr/include/unistd.h:277:21: note: previous declaration as ‘typedef
__socklen_t socklen_t’
  277 | typedef __socklen_t socklen_t;
      |                     ^~~~~~~~~
...
after commit 05a6b8c28b "Don't unnecessarily redefine 'socklen_t' type in
MinGW builds".

The root cause is a typo in gdb/configure.ac, using sys/sockets.h where
sys/socket.h was meant:
...
AC_CHECK_HEADERS([sys/sockets.h])
...

Fix the typo.

Build and tested on x86_64-linux.

gdb/ChangeLog:

2020-07-27  Tom de Vries  <tdevries@suse.de>

	* configure.ac: Fix sys/sockets.h -> sys/socket.h typo.
	* config.in: Regenerate.
	* configure: Regenerate.
2020-07-27 13:46:27 +02:00
05a6b8c28b Don't unnecessarily redefine 'socklen_t' type in MinGW builds.
The original configure-time tests in gdb/ and gdbserver/ failed to
detect that 'socklen_t' is defined in MinGW headers because the test
program included only sys/socket.h, which is absent in MinGW system
headers.  However on MS-Windows this data type is declared in another
header, ws2tcpip.h.  The modified test programs try using ws2tcpip.h
if sys/socket.h is unavailable.

Thanks to Joel Brobecker who helped me regenerate the configure
scripts and the config.in files.

gdb/ChangeLog:
2020-07-26  Eli Zaretskii  <eliz@gnu.org>

	* configure.ac (AC_CHECK_HEADERS): Check for sys/socket.h and
	ws2tcpip.h.  When checking whether socklen_t type is defined, use
	ws2tcpip.h if it is available and sys/socket.h isn't.
	* configure: Regenerate.
	* config.in: Regenerate.

gdbserver/ChangeLog:
2020-07-26  Eli Zaretskii  <eliz@gnu.org>

	* configure.ac (AC_CHECK_HEADERS): Add ws2tcpip.h.
	When checking whether socklen_t type is defined, use ws2tcpip.h if
	it is available and sys/socket.h isn't.
	* configure: Regenerate.
	* config.in: Regenerate.
2020-07-26 19:35:48 +03:00
ae5369e773 guile: Add support for Guile 3.0.
gdb/ChangeLog
2020-06-28  Ludovic Courtès  <ludo@gnu.org>

	* guile/scm-math.c (vlscm_integer_fits_p): Use 'uintmax_t'
	and 'intmax_t' instead of 'scm_t_uintmax' and 'scm_t_intmax',
	which are deprecated in Guile 3.0.
	* configure.ac (try_guile_versions): Add "guile-3.0".
	* configure (try_guile_versions): Regenerate.
	* NEWS: Update entry.

gdb/testsuite/ChangeLog
2020-06-28  Ludovic Courtès  <ludo@gnu.org>

	* gdb.guile/source2.scm: Add #f first argument to 'format'.
	* gdb.guile/types-module.exp: Remove "ERROR:" from
	regexps since Guile 3.0 no longer prints that.

gdb/doc/ChangeLog
2020-06-28  Ludovic Courtès  <ludo@gnu.org>

	* doc/guile.texi (Guile Introduction): Mention Guile 3.0.

Change-Id: Iff116c2e40f334e4e0ca4e759a097bfd23634679
2020-07-20 11:00:55 -04:00
68cf161c24 guile: Add support for Guile 2.2.
This primarily updates code that uses the I/O port API of Guile.

gdb/ChangeLog
2020-06-28  Ludovic Courtès  <ludo@gnu.org>
            Doug Evans  <dje@google.com>

	PR gdb/21104
	* guile/scm-ports.c (USING_GUILE_BEFORE_2_2): New macro.
	(ioscm_memory_port)[read_buf_size, write_buf_size]: Wrap in #if
	USING_GUILE_BEFORE_2_2.
	(stdio_port_desc, memory_port_desc) [!USING_GUILE_BEFORE_2_2]:
	Change type to 'scm_t_port_type *'.
	(natural_buffer_size) [!USING_GUILE_BEFORE_2_2]: New variable.
	(ioscm_open_port) [USING_GUILE_BEFORE_2_2]: Add 'stream'
	parameter and honor it.  Update callers.
	(ioscm_open_port) [!USING_GUILE_BEFORE_2_2]: New function.
	(ioscm_read_from_port, ioscm_write) [!USING_GUILE_BEFORE_2_2]: New
	functions.
	(ioscm_fill_input, ioscm_input_waiting, ioscm_flush): Wrap in #if
	USING_GUILE_BEFORE_2_2.
	(ioscm_init_gdb_stdio_port) [!USING_GUILE_BEFORE_2_2]: Use
	'ioscm_read_from_port'.  Call 'scm_set_port_read_wait_fd'.
	(ioscm_init_stdio_buffers) [!USING_GUILE_BEFORE_2_2]: New function.
	(gdbscm_stdio_port_p) [!USING_GUILE_BEFORE_2_2]: Use 'SCM_PORTP'
	and 'SCM_PORT_TYPE'.
	(gdbscm_memory_port_end_input, gdbscm_memory_port_seek)
	(ioscm_reinit_memory_port): Wrap in #if USING_GUILE_BEFORE_2_2.
	(gdbscm_memory_port_read, gdbscm_memory_port_write)
	(gdbscm_memory_port_seek, gdbscm_memory_port_close)
	[!USING_GUILE_BEFORE_2_2]: New functions.
	(gdbscm_memory_port_print): Remove use of 'SCM_PTOB_NAME'.
	(ioscm_init_memory_port_type) [!USING_GUILE_BEFORE_2_2]: Use
	'gdbscm_memory_port_read'.
	Wrap 'scm_set_port_end_input', 'scm_set_port_flush', and
	'scm_set_port_free' calls in #if USING_GUILE_BEFORE_2_2.
	(gdbscm_get_natural_buffer_sizes) [!USING_GUILE_BEFORE_2_2]: New
	function.
	(ioscm_init_memory_port): Remove.
	(ioscm_init_memory_port_stream): New function
	(ioscm_init_memory_port_buffers) [USING_GUILE_BEFORE_2_2]: New
	function.
	(gdbscm_memory_port_read_buffer_size) [!USING_GUILE_BEFORE_2_2]:
	Return scm_from_uint (0).
	(gdbscm_set_memory_port_read_buffer_size_x)
	[!USING_GUILE_BEFORE_2_2]: Call 'scm_setvbuf'.
	(gdbscm_memory_port_write_buffer_size) [!USING_GUILE_BEFORE_2_2]:
	Return scm_from_uint (0).
	(gdbscm_set_memory_port_write_buffer_size_x)
	[!USING_GUILE_BEFORE_2_2]: Call 'scm_setvbuf'.
	* configure.ac (try_guile_versions): Add "guile-2.2".
	* configure: Regenerate.
	* NEWS: Add entry.

gdb/testsuite/ChangeLog
2020-06-28  Ludovic Courtès  <ludo@gnu.org>

	* gdb.guile/scm-error.exp ("source $remote_guile_file_1"): Relax
	error regexp to match on Guile 2.2.

gdb/doc/ChangeLog
2020-06-28  Ludovic Courtès  <ludo@gnu.org>

	* guile.texi (Memory Ports in Guile): Mark
	'memory-port-read-buffer-size',
	'set-memory-port-read-buffer-size!',
	'memory-port-write-buffer-size',
	'set-memory-port-read-buffer-size!' as deprecated.
	* doc/guile.texi (Guile Introduction): Clarify which Guile
	versions are supported.

Change-Id: Ib119b10a2787446e0ae482a5e1b36d809c44bb31
2020-07-20 10:59:47 -04:00
1776e3e59c Fix --enable-libctf and --disable-static
This fixes test runs and compilation when --disable-libctf,
--disable-static, or --enable-shared are passed.

Changes since v2: Use GCC_ENABLE and fix indentation.  Fix prototype
using 'void'.  Use 'unsupported' and gdb_caching_proc.

Changes since v3: Adapt to upstream changes providing skip_ctf_tests.

Changes since v4: Adapt to upstream changes in the seven months (!)
since I last looked at this.

gdb/ChangeLog
	* configure.ac: Add --enable-libctf: handle --disable-static
	properly.
	* acinclude.m4: sinclude ../config/enable.m4.
	* Makefile.in (aclocal_m4_deps): Adjust accordingly.
	(LIBCTF): Substitute in.
	(CTF_DEPS): New, likewise.
	(CLIBS): libctf needs symbols from libbfd: move earlier.
	(CDEPS): Use CTF_DEPS, not LIBCTF, now LIBCTF can include rpath
	flags.
	* ctfread.c: Surround in ENABLE_LIBCTF.
	(elfctf_build_psymtabs) [!ENABLE_LIBCTF]: New stub.
	* configure: Regenerate.
	* config.in: Likewise.

gdb/testsuite/ChangeLog
	* configure.ac: Add --enable-libctf.
	* aclocal.m4: sinclude ../config/enable.m4.
	* Makefile.in (site.exp): Add enable_libctf to site.exp.
	* lib/gdb.exp (skip_ctf_tests): Use it.
	* gdb.base/ctf-constvars.exp: Error message tweak.
	* gdb.base/ctf-ptype.exp: Likewise.
	* configure: Regenerate.
2020-06-26 15:56:38 +01:00
112c22ed1f gdb: change bug URL to https
gdb/ChangeLog:

	* configure.ac (ACX_BUGURL): change bug URL to https.

Signed-off-by: Jonny Grant <jg@jguk.org>
Change-Id: If8d939e50c830e3e452c3e8f7a7aee06d9c96645
2020-05-30 11:18:53 -04:00
1eb3991427 gdb, gdbserver: remove configure check for fs_base/gs_base in user_regs_struct
I recently stumbled on this code mentioning Linux kernel 2.6.25, and
thought it could be time for some spring cleaning (newer GDBs probably
don't need to supports 12-year old kernels).  I then found that the
"legacy" case is probably broken anyway, which gives an even better
motivation for its removal.

In short, this patch removes the configure checks that check if
user_regs_struct contains the fs_base/gs_base fields and adjusts all
uses of the HAVE_STRUCT_USER_REGS_STRUCT_{FS,GS}_BASE macros.  The
longer explanation/rationale follows.

Apparently, Linux kernels since 2.6.25 (that's from 2008) have been
reliably providing fs_base and gs_base as part of user_regs_struct.
Commit df5d438e33d7 in the Linux kernel [1] seems related.  This means
that we can get these values by reading registers with PTRACE_GETREGS.
Previously, these values were obtained using a separate
PTRACE_ARCH_PRCTL ptrace call.

First, I'm not even sure the configure check was really right in the
first place.

The user_regs_struct used by GDB comes from
/usr/include/x86_64-linux-gnu/sys/user.h (or equivalent on other
distros) and is provided by glibc.  glibc has had the fs_base/gs_base
fields in there for a very long time, at least since this commit from
2001 [2].  The Linux kernel also has its version of user_regs_struct,
which I think was exported to user-space at some point.  It included the
fs_base/gs_base fields since at least this 2002 commit [3].  In any
case, my conclusion is that the fields were there long before the
aforementioned Linux kernel commit.  The kernel commit didn't add these
fields, it only made sure that they have reliable values when obtained
with PTRACE_GETREGS.

So, checking for the presence of the fs_base/gs_base fields in struct
user_regs_struct doesn't sound like a good way of knowing if we can
reliably get the fs_base/gs_base values from PTRACE_GETREGS.  My guess
is that if we were using that strategy on a < 2.6.25 kernel, things
would not work correctly:

- configure would find that the user_regs_struct has the fs_base/gs_base
  fields (which are probided by glibc anyway)
- we would be reading the fs_base/gs_base values using PTRACE_GETREGS,
  for which the kernel would provide unreliable values

Second, I have tried to see how things worked by forcing GDB to not use
fs_base/gs_base from PTRACE_GETREGS (forcing it to use the "legacy"
code, by configuring with

  ac_cv_member_struct_user_regs_struct_gs_base=no ac_cv_member_struct_user_regs_struct_fs_base=no

Doing so breaks writing registers back to the inferior.  For example,
calling an inferior functions gives an internal error:

    (gdb) p malloc(10)
    /home/smarchi/src/binutils-gdb/gdb/i387-tdep.c:1408: internal-error: invalid i387 regnum 152

The relevant last frames where this error happens are:

    #8  0x0000563123d262fc in internal_error (file=0x563123e93fd8 "/home/smarchi/src/binutils-gdb/gdb/i387-tdep.c", line=1408, fmt=0x563123e94482 "invalid i387 regnum %d") at /home/smarchi/src/binutils-gdb/gdbsupport/errors.cc:55
    #9  0x0000563123047d0d in i387_collect_xsave (regcache=0x5631269453f0, regnum=152, xsave=0x7ffd38402a20, gcore=0) at /home/smarchi/src/binutils-gdb/gdb/i387-tdep.c:1408
    #10 0x0000563122c69e8a in amd64_collect_xsave (regcache=0x5631269453f0, regnum=152, xsave=0x7ffd38402a20, gcore=0) at /home/smarchi/src/binutils-gdb/gdb/amd64-tdep.c:3448
    #11 0x0000563122c5e94c in amd64_linux_nat_target::store_registers (this=0x56312515fd10 <the_amd64_linux_nat_target>, regcache=0x5631269453f0, regnum=152) at /home/smarchi/src/binutils-gdb/gdb/amd64-linux-nat.c:335
    #12 0x00005631234c8c80 in target_store_registers (regcache=0x5631269453f0, regno=152) at /home/smarchi/src/binutils-gdb/gdb/target.c:3485
    #13 0x00005631232e8df7 in regcache::raw_write (this=0x5631269453f0, regnum=152, buf=0x56312759e468 "@\225\372\367\377\177") at /home/smarchi/src/binutils-gdb/gdb/regcache.c:765
    #14 0x00005631232e8f0c in regcache::cooked_write (this=0x5631269453f0, regnum=152, buf=0x56312759e468 "@\225\372\367\377\177") at /home/smarchi/src/binutils-gdb/gdb/regcache.c:778
    #15 0x00005631232e75ec in regcache::restore (this=0x5631269453f0, src=0x5631275eb130) at /home/smarchi/src/binutils-gdb/gdb/regcache.c:283
    #16 0x0000563123083fc4 in infcall_suspend_state::restore (this=0x5631273ed930, gdbarch=0x56312718cf20, tp=0x5631270bca90, regcache=0x5631269453f0) at /home/smarchi/src/binutils-gdb/gdb/infrun.c:9103
    #17 0x0000563123081eed in restore_infcall_suspend_state (inf_state=0x5631273ed930) at /home/smarchi/src/binutils-gdb/gdb/infrun.c:9151

The problem seems to be that amd64_linux_nat_target::store_registers
calls amd64_native_gregset_supplies_p to know whether gregset provides
fs_base.  When !HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE,
amd64_native_gregset_supplies_p returns false.  store_registers
therefore assumes that it must be an "xstate" register.  This is of
course wrong, and that leads to the failed assertion when
i387_collect_xsave doesn't recognize the register.

amd64_linux_nat_target::store_registers could probably be fixed to
handle this case, but I don't think it's worth it, given that it would
only be to support very old kernels.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=df5d438e33d7fc914ba9b6e0d6b019a8966c5fcc
[2] https://sourceware.org/git/?p=glibc.git;a=commit;h=c9cf6ddeebb7bb
[3] https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=88e4bc32686ebd0b1111a94f93eba2d334241f68

gdb/ChangeLog:

	* configure.ac: Remove check for fs_base/gs_base in
	user_regs_struct.
	* configure: Re-generate.
	* config.in: Re-generate.
	* amd64-nat.c (amd64_native_gregset_reg_offset): Adjust.
	* amd64-linux-nat.c (amd64_linux_nat_target::fetch_registers,
	amd64_linux_nat_target::store_registers, ps_get_thread_area, ): Adjust.

gdbserver/ChangeLog:

	* configure.ac: Remove check for fs_base/gs_base in
	user_regs_struct.
	* configure: Re-generate.
	* config.in: Re-generate.
	* linux-x86-low.cc (x86_64_regmap, x86_fill_gregset,
	x86_store_gregset): Adjust.
2020-04-27 10:47:50 -04:00
8ae8e19796 Move event-loop configury to common.m4
gdb_select.h and the event loop require some configure checks, so this
moves the needed checks to common.m4 and updates the configure
scripts.

gdb/ChangeLog
2020-04-13  Tom Tromey  <tom@tromey.com>

	* configure: Rebuild.
	* configure.ac: Remove checks that are now in GDB_AC_COMMON.

gdbserver/ChangeLog
2020-04-13  Tom Tromey  <tom@tromey.com>

	* configure: Rebuild.
	* config.in: Rebuild.

gdbsupport/ChangeLog
2020-04-13  Tom Tromey  <tom@tromey.com>

	* config.in, configure: Rebuild.
	* common.m4 (GDB_AC_COMMON): Check for poll.h, sys/poll.h,
	sys/select.h, and poll.
2020-04-13 14:10:03 -06:00
74cd3f9d7e Don't include selftests objects in build when unit tests are disabled
While working on the preceding selftests patches, I noticed that some
selftests-specific files are included in the build even when selftests
are disabled, namely disasm-selftest.c and gdbarch-selftests.c.  These
files are entirely #if'ed out when building with selftests disabled.

This is not a huge problem, but I think it would make more sense if
these files were simply not built.

With this patch, I propose to put all the selftests-specific source
files into a SELFTESTS_SRCS Makefile variable (even selftest-arch.c,
which is currently added by the configure script).

gdb/ChangeLog:

	* Makefile.in (SUBDIR_UNITTESTS_SRCS): Rename to...
	(SELFTESTS_SRCS): ... this.  Add disasm-selftests.c,
	gdbarch-selfselftests.c and selftest-arch.c.
	(SUBDIR_UNITTESTS_OBS): Rename to...
	(SELFTESTS_OBS): ... this.
	(COMMON_SFILES): Remove disasm-selftests.c and
	gdbarch-selftests.c.
	* configure.ac: Don't add selftest-arch.{c,o} to
	CONFIG_{SRCS,OBS}.
	* disasm-selftests.c, gdbarch-selftests.c: Remove GDB_SELF_TEST
	preprocessor conditions.
2020-03-12 14:18:36 -04:00
db6878ac55 Move sourcing of development.sh to GDB_AC_COMMON
The same is done for gdb, gdbserver and gdbsupport.  I therefore think
it makes sense to move that to GDB_AC_COMMON.

It is required to move the call to GDB_AC_COMMON so it is before
GDB_AC_SELFTEST in gdbserver/configure.ac, otherwise the $development
variable isn't set when the code behind GDB_AC_SELFTEST executes.

gdb/ChangeLog:

	* configure.ac: Don't source bfd/development.sh.
	* selftest.m4: Modify comment.
	* configure: Re-generate.

gdbserver/ChangeLog:

	* configure.ac: Don't source bfd/development.sh, move
	GDB_AC_COMMON higher.
	* configure: Re-generate.

gdbsupport/ChangeLog:

	* configure.ac: Don't source bfd/development.sh.
	* common.m4: Source bfd/development.sh.
	* configure: Re-generate.
2020-03-12 14:18:00 -04:00
0d79cdc494 Add debuginfod support to GDB
debuginfod is a lightweight web service that indexes ELF/DWARF debugging
resources by build-id and serves them over HTTP.

This patch enables GDB to query debuginfod servers for separate debug
files and source code when it is otherwise not able to find them.

GDB can be built with debuginfod using the --with-debuginfod configure
option.

This requires that libdebuginfod be installed and found at configure time.

debuginfod is packaged with elfutils, starting with version 0.178.

For more information see https://sourceware.org/elfutils/.

Tested on x86_64 Fedora 31.

gdb/ChangeLog:
2020-02-26  Aaron Merey  <amerey@redhat.com>

        * Makefile.in: Handle optional debuginfod support.
        * NEWS: Update.
        * README: Add --with-debuginfod summary.
        * config.in: Regenerate.
        * configure: Regenerate.
        * configure.ac: Handle optional debuginfod support.
        * debuginfod-support.c: debuginfod helper functions.
        * debuginfod-support.h: Ditto.
        * doc/gdb.texinfo: Add --with-debuginfod to configure options
        summary.
        * dwarf2/read.c (dwarf2_get_dwz_file): Query debuginfod servers
        when a dwz file cannot be found.
        * elfread.c (elf_symfile_read): Query debuginfod servers when a
        debuginfo file cannot be found.
        * source.c (open_source_file): Query debuginfod servers when a
        source file cannot be found.
        * top.c (print_gdb_configuration): Include
        --{with,without}-debuginfod in the output.

gdb/testsuite/ChangeLog:
2020-02-26  Aaron Merey  <amerey@redhat.com>

        * gdb.debuginfod: New directory for debuginfod tests.
        * gdb.debuginfod/main.c: New test file.
        * gdb.debuginfod/fetch_src_and_symbols.exp: New tests.
2020-02-26 17:40:49 -05:00
d13c7322fe gdb: Allow more control over where to find python libraries
The motivation behind this commit is to make it easier to bundle the
Python *.py library files with GDB when statically linking GDB against
libpython.  The Python files will be manually added into the GDB
installation tree, and GDB should be able to find them at run-time.
The installation tree will look like this:

  .
  |-- bin/
  |-- include/
  |-- lib/
  |   `-- python3.8/
  `-- share/

The benefit here is that the entire installation tree can be bundled
into a single archive and copied to another machine with a different
version of Python installed, and GDB will still work, including its
Python support.

In use the new configure options would be used something like this,
first build and install a static Python library:

  mkdir python
  cd python
  # Clone or download Python into a src/ directory.
  mkdir build
  export PYTHON_INSTALL_PATH=$PWD/install
  cd build
  ../src/configure --disable-shared --prefix=$PYTHON_INSTALL_PATH
  make
  make install

Now build and install GDB:

  mkdir binutils-gdb
  cd binutils-gdb
  # Clone or download GDB into a src/ directory.
  mkdir build
  export GDB_INSTALL_DIR=$PWD/install
  cd build
  ../src/configure \
      --prefix=$GDB_INSTALL_DIR \
      --with-python=$PYTHON_INSTALL_PATH/bin/python3 \
      --with-python-libdir=$GDB_INSTALL_DIR/lib
  make all-gdb
  make install-gdb

Finally, copy the Python libraries into the GDB install:

  cp -r $PYTHON_INSTALL_DIR/lib/python3.8/ $GDB_INSTALL_DIR/lib

After this the Python src, build, and install directories are no
longer needed and can be deleted.

If the new --with-python-libdir option is not used then the existing
behaviour is left unchanged, GDB will look for the Python libraries in
the lib/ directory within the python path.  The concatenation of the
python prefix and the string 'lib/' is now done at configure time,
rather than at run time in GDB as it was previous, however, this was
never something that the user had dynamic control over, so there's no
loss of functionality.

gdb/ChangeLog:

	* config.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Add --with-python-libdir option.
	* main.c: Use WITH_PYTHON_LIBDIR.
2020-02-20 10:14:43 +00:00
919adfe840 Move gdbserver to top level
This patch moves gdbserver to the top level.

This patch is as close to a pure move as possible -- gdbserver still
builds its own variant of gnulib and gdbsupport.  Changing this will
be done in a separate patch.

[v2] Note that, per Simon's review comment, this patch changes the
tree so that gdbserver is not built for or1k or score.  This makes
sense, because there is apparently not actually a gdbserver port here.

[v3] This version of the patch also splits out some configury into a
new file, gdbserver/configure.host, so that the top-level configure
script can simply rely on it in order to decide whether gdbserver
should be built.

[v4] This version adds documentation and removes some unnecessary
top-level dependencies.

[v5] Update docs to mention "make all-gdbserver" and change how
top-level configure decides whether to build gdbserver, switching to a
single, shared script.

Tested by the buildbot.

ChangeLog
2020-02-07  Tom Tromey  <tom@tromey.com>
	    Pedro Alves  <palves@redhat.com>

	* src-release.sh (GDB_SUPPORT_DIRS): Add gdbserver.
	* gdbserver: New directory, moved from gdb/gdbserver.
	* configure.ac (host_tools): Add gdbserver.
	Only build gdbserver on certain systems.
	* Makefile.in, configure: Rebuild.
	* Makefile.def (host_modules, dependencies): Add gdbserver.
	* MAINTAINERS: Add gdbserver.

gdb/ChangeLog
2020-02-07  Tom Tromey  <tom@tromey.com>

	* README: Update gdbserver documentation.
	* gdbserver: Move to top level.
	* configure.tgt (build_gdbserver): Remove.
	* configure.ac: Remove --enable-gdbserver.
	* configure: Rebuild.
	* Makefile.in (distclean): Don't mention gdbserver.

Change-Id: I826b7565b54604711dc7a11edea0499cd51ff39e
2020-02-07 08:42:25 -07:00
05ea2a0510 Move many configure checks to common.m4
This moves many needed configure checks from gdb and gdbserver into
common.m4.  This helps gdbsupport, nat, and target be self-contained.

The result is a bit spaghetti-ish, because gdbsupport uses another m4
file from gdb/.  The resulting code is somewhat non-obvious.  However,
these problems already exist, so it's not really that much worse than
what is already done.

gdb/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* configure: Rebuild.
	* configure.ac: Move many checks to ../gdbsupport/common.m4.

gdb/gdbserver/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* configure: Rebuild.
	* configure.ac: Remove any checks that were added to common.m4.
	* acinclude.m4: Include lib-ld.m4, lib-prefix.m4, and
	lib-link.m4.

gdbsupport/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* configure, Makefile.in, aclocal.m4, common.m4, config.in:
	Rebuild.
	* common.m4 (GDB_AC_COMMON): Move many checks from
	gdb/configure.ac.
	* acinclude.m4: Include bfd.m4, ptrace.m4.

Change-Id: I931eaa94065df268b30a2f1354390710df89c7f8
2020-01-14 16:25:03 -07:00
01027315f5 Move gdbsupport to the top level
This patch moves the gdbsupport directory to the top level.  This is
the next step in the ongoing project to move gdbserver to the top
level.

The bulk of this patch was created by "git mv gdb/gdbsupport gdbsupport".

This patch then adds a build system to gdbsupport and wires it into
the top level.  Then it changes gdb to use the top-level build.

gdbserver, on the other hand, is not yet changed.  It still does its
own build of gdbsupport.

ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* src-release.sh (GDB_SUPPORT_DIRS): Add gdbsupport.
	* MAINTAINERS: Add gdbsupport.
	* configure: Rebuild.
	* configure.ac (configdirs): Add gdbsupport.
	* gdbsupport: New directory, move from gdb/gdbsupport.
	* Makefile.def (host_modules, dependencies): Add gnulib.
	* Makefile.in: Rebuild.

gdb/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* nat/x86-linux-dregs.c: Include configh.h.
	* nat/linux-ptrace.c: Include configh.h.
	* nat/linux-btrace.c: Include configh.h.
	* defs.h: Include config.h, bfd.h.
	* configure.ac: Don't source common.host.
	(CONFIG_OBS, CONFIG_SRCS): Remove gdbsupport files.
	* configure: Rebuild.
	* acinclude.m4: Update path.
	* Makefile.in (SUPPORT, LIBSUPPORT, INCSUPPORT): New variables.
	(CONFIG_SRC_SUBDIR): Remove gdbsupport.
	(INTERNAL_CFLAGS_BASE): Add INCSUPPORT.
	(CLIBS): Add LIBSUPPORT.
	(CDEPS): Likewise.
	(COMMON_SFILES): Remove gdbsupport files.
	(HFILES_NO_SRCDIR): Likewise.
	(stamp-version): Update path to create-version.sh.
	(ALLDEPFILES): Remove gdbsupport files.

gdb/gdbserver/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* server.h: Include config.h.
	* gdbreplay.c: Include config.h.
	* configure: Rebuild.
	* configure.ac: Don't source common.host.
	* acinclude.m4: Update path.
	* Makefile.in (INCSUPPORT): New variable.
	(INCLUDE_CFLAGS): Add INCSUPPORT.
	(SFILES): Update paths.
	(version-generated.c): Update path to create-version.sh.
	(gdbsupport/%-ipa.o, gdbsupport/%.o): Update paths.

gdbsupport/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* common-defs.h: Add GDBSERVER case.  Update includes.
	* acinclude.m4, aclocal.m4, config.in, configure, configure.ac,
	Makefile.am, Makefile.in, README: New files.
	* Moved from ../gdb/gdbsupport/

Change-Id: I07632e7798635c1bab389bf885971e584fb4bb78
2020-01-14 16:25:02 -07:00
b2ceabe8f0 Consolidate definition of USE_WIN32API
I noticed that USE_WIN32API is defined separately by gdbserver and
gdb.  However, because it is used by code in gdbsupport, it should be
defined by common.m4.  This approach ensures that the code will
continue to work when it is moved to the top level.

gdb/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* gdbsupport/common.m4 (GDB_AC_COMMON): Define WIN32APILIBS and
	USE_WIN32API when needed.
	* configure.ac (USE_WIN32API): Don't define.
	(WIN32LIBS): Use WIN32APILIBS.
	* configure: Rebuild.

gdb/gdbserver/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* configure.ac (LIBS): Use WIN32APILIBS.
	(USE_WIN32API): Don't define.
	* configure: Rebuild.

Change-Id: I40d524d5445ebfb452b36f4d0e102f0b1e1089df
2020-01-14 16:25:02 -07:00
b811d2c292 Update copyright year range in all GDB files.
gdb/ChangeLog:

        Update copyright year range in all GDB files.
2020-01-01 10:20:53 +04:00
0ad6b8ee70 Consistently quote variables used with "test"
This ensures that empty variables and variables with spaces are handled
correctly.

Code was inconsistent on whether the constant string (e.g. yes/no)
should also be quoted; I tried to be consistent with surrounding code.

This fixes the error Eli reported during configure with mingw (though that
was not fatal).

gdb/ChangeLog:

2019-12-19  Christian Biesinger  <cbiesinger@google.com>

	* configure: Regenerate.
	* configure.ac: Quote variable arguments of test.
	* gdbsupport/common.m4: Likewise.

gdb/gdbserver/ChangeLog:

2019-12-19  Christian Biesinger  <cbiesinger@google.com>

	* configure: Regenerate.
	* configure.ac: Quote variable arguments of test.

Change-Id: I220e78b52c7db88b9dd058eda604635b03464fac
2019-12-19 13:30:50 -06:00
cd850b40cc Use gnulib's strerror_r on MinGW
There is no need to keep mingw-strerror around; we can just always use
the code from posix-strerror. The main reason we had that code, it
seems, is to handle winsock error codes, but gnulib's version
handles those.

Unfortunately the code can't be moved into common-utils.c because
libinproctrace.so uses common-utils but not gnulib.

gdb/ChangeLog:

2019-11-15  Christian Biesinger  <cbiesinger@google.com>

	* Makefile.in: Replace {posix,mingw}-strerror.c with safe-strerror.c.
	* configure: Regenerate.
	* configure.ac: Don't source common.host.
	* gdbsupport/common.host: Remove.
	* gdbsupport/mingw-strerror.c: Remove.
	* gdbsupport/posix-strerror.c: Rename to...
	* gdbsupport/safe-strerror.c: ...this.

gdb/gdbserver/ChangeLog:

2019-11-15  Christian Biesinger  <cbiesinger@google.com>

	* Makefile.in: Add safe-strerror.c.
	* configure: Regenerate.
	* configure.ac: Don't source common.host.

Change-Id: I9e6d8a752fc398784201f370cafee65e0ea05474
2019-11-15 13:31:36 -08:00
e48f6033b0 Move check for strerror_r to common.m4 where it belongs
gdb/ChangeLog:

2019-11-01  Christian Biesinger  <cbiesinger@google.com>

	* configure: Regenerate.
	* configure.ac: Remove check for strerror_r.
	* gdbsupport/common.m4: Check for strerror_r.

gdb/gdbserver/ChangeLog:

2019-11-01  Christian Biesinger  <cbiesinger@google.com>

	* configure: Regenerate.
	* configure.ac: Remove check for strerror_r.

Change-Id: Ibc290c3f84b1db23e998cffdbe2c1f97651d2a8d
2019-11-01 10:13:44 -05:00
b231e86ac9 Use strerror_r in safe_strerror if available
Also stores the result in a thread-local static variable and
changes the return value to a const char*.

This is already important because Guile creates threads and
Python can create threads, but with the patch series here:
https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/176
GDB itself will create threads, too.

gdb/ChangeLog:

2019-10-31  Christian Biesinger  <cbiesinger@google.com>

	* configure: Regenerate.
	* configure.ac: Check for strerror_r.
	* gdbsupport/common-utils.h (safe_strerror): Change return value
	to const char * and document that this function is now threadsafe.
	* gdbsupport/posix-strerror.c (safe_strerror): Make buf
	thread_local and call strerror_r, if available.
	* utils.c (perror_string): Update.
	(print_sys_errmsg): Update.

Change-Id: I81048fbaf148035c221c528727f7efe58ba528eb
2019-10-31 15:14:14 -05:00
ed2a222951 Load system gdbinit files from a directory
Adds a configure option --with-system-gdbinit-dir to specify a directory
in which to look for gdbinit files.  All files in this directory are
loaded on startup (subject to -n/-nx as usual) as long as the extension
matches a known and enabled scripting language (.gdb/.py/.scm).

This also changes get_ext_lang_of_file to support ".gdb" files, similar
to get_ext_lang_defn's handling of EXT_LANG_GDB.

gdb/ChangeLog:

2019-10-29  Christian Biesinger  <cbiesinger@google.com>

	* NEWS: Mention new --with-system-gdbinit-dir option.
	* config.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Add new option --with-system-gdbinit-dir.
	* extension.c (get_ext_lang_of_file): Return extension_language_gdb
	for a ".gdb" suffix.
	* main.c (get_init_files): Change system_gdbinit argument to
	a vector and return the files in SYSTEM_GDBINIT_DIR in
	addition to SYSTEM_GDBINIT.
	(captured_main_1): Update.
	(print_gdb_help): Update.
	* top.c (print_gdb_configuration): Also print the value of
	SYSTEM_GDBINIT_DIR.

gdb/doc/ChangeLog:

2019-10-29  Christian Biesinger  <cbiesinger@google.com>

	* Makefile.in: Also set SYSTEM_GDBINIT_DIR for the info manual
	generation.
	* gdb.texinfo (many sections): Document new --with-system-gdbinit-dir
	option.

Change-Id: If233859ecc21bc6421d589b37cd658a3c7d030f2
2019-10-29 13:43:04 -05:00
cbb5a2ea49 Remove python_has_threads check in configure.ac
The only use of python_has_threads has been removed in
commit 404f29021abaef86a341663444fb069eb1f0282a

gdb/ChangeLog:

2019-10-24  Christian Biesinger  <cbiesinger@google.com>

	* configure: Rebuild.
	* configure.ac: Remove code that sets python_has_threads.

Change-Id: I75f1b873562bc2abc6f2db17699a3e82fcfd2de3
2019-10-24 14:14:07 -05:00
71737c435d Simplify Python checks in configure.ac
The version checking code is not necessary. It is only used to define
HAVE_LIBPYTHON2_6 or HAVE_LIBPYTHON2_7, which is not used anywhere.

If a version check is desired, the PY_{MAJOR,MINOR}_VERSION macro from
the Python headers can be (and is) used, which does not require updating
configure.ac whenever a new Python version is released.

gdb/ChangeLog:

2019-10-24  Christian Biesinger  <cbiesinger@google.com>

	* config.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Remove the code that uses sed to get the python
	version and defines HAVE_LIBPYTHON2_6 / HAVE_LIBPYTHON2_7.

Change-Id: I07073870d9040c2bc8519882c8b3c1368edd4513
2019-10-24 13:47:37 -05:00
c12d372d26 Check for sigprocmask in common.m4
I noticed that gdbsupport uses HAVE_SIGPROCMASK, but common.m4 does
not check for it.  This means that gdbserver may not compile some
gdbsupport code properly.  This patch fixes this error.

gdb/ChangeLog
2019-10-23  Tom Tromey  <tom@tromey.com>

	* configure: Rebuild.
	* configure.ac: Don't check for sigprocmask.
	* gdbsupport/common.m4 (GDB_AC_COMMON): Check for sigprocmask.

gdb/gdbserver/ChangeLog
2019-10-23  Tom Tromey  <tom@tromey.com>

	* configure, config.in: Rebuild.

Change-Id: I2c0a4dd2c376507b9483b38707a242382faa8163
2019-10-23 09:06:21 -06:00
ccb1ba6229 Use libxxhash for hashing, if present
XXHash is faster than htab_hash_string:
------------------------------------------------------------
Benchmark                     Time           CPU Iterations
------------------------------------------------------------
BM_xxh3                      11 ns         11 ns   65887249
BM_xxh32                     19 ns         19 ns   36511877
BM_xxh64                     16 ns         16 ns   42964585
BM_hash_string              182 ns        182 ns    3853125
BM_iterative_hash            77 ns         77 ns    9087638

Unfortunately, XXH3 is still experimental (see
https://github.com/Cyan4973/xxHash#user-content-new-experimental-hash-algorithm)

However, regular XXH64 is still a lot faster than
htab_hash_string per my benchmark above. I used the
following string for the benchmark:
static constexpr char str[] = "_ZZZL13make_gdb_typeP7gdbarchP10tdesc_typeEN16gdb_type_creator19make_gdb_type_flagsEPK22tdesc_type_with_fieldsE19__PRETTY_FUNCTION__";

htab_hash_string is currently 4.35% + 7.98% (rehashing) of gdb
startup when attaching to Chrome's content_shell.

An additional 5.21% is spent in msymbol_hash, which does not use
this hash function. Unfortunately, since it has to lowercase the
string, it can't use this hash function.
BM_msymbol_hash                52 ns         52 ns   13281495

It may be worth investigating if strlen+XXHash is still faster than
htab_hash_string, which would make it easier to use in more places.

Debian ships xxhash as libxxhash{0,-dev}. Fedora ships it as xxhash-devel.

gdb/ChangeLog:

2019-10-22  Christian Biesinger  <cbiesinger@google.com>

	* Makefile.in: Link with libxxhash.
	* config.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Search for libxxhash.
	* utils.c (fast_hash): Use xxhash if present.

Change-Id: Icab218388b9f829522ed3977f04301ae6d4fc4ca
2019-10-22 11:47:24 -05:00
a0a461e5b4 Fix creation of nm.h when configure is changed
My earlier patch -- commit c5adaa192 ("Fix creation of stamp-h by
gdb's configure script") -- broke the creation of nm.h.  In
particular, configure removes nm.h, so if you touch configure and
rebuild, nothing will re-create the link, breaking the build.

This patch fixes the bug, and also updates configure.ac to use
AC_CONFIG_LINKS, rather than the obsolete AC_LINK_FILES.

Finally, I noticed that gcore is in generated_files in the
Makefile.in.  I think this is incorrect, as generated_files is only
needed for files that can be the target of a #include.  So, this patch
removes it.

gdb/ChangeLog
2019-10-21  Tom Tromey  <tom@tromey.com>

	* configure.ac (nm.h): Conditionally create nm.h link.  Subst
	NM_H.   Use AC_CONFIG_LINKS.
	* configure: Rebuild.
	* Makefile.in (NM_H): New variable.
	(generated_files): Add NM_H.  Remove gcore.
	(nm.h, stamp-nmh): New targets.

Change-Id: I8dd539785d52455e85389425e4bb996c8a127a0e
2019-10-21 07:45:30 -06:00
c5adaa1921 Fix creation of stamp-h by gdb's configure script
I happened to notice that "make" would always print:

    CONFIG_HEADERS=config.h:config.in \
      CONFIG_COMMANDS="default depdir" \
      CONFIG_FILES= \
      CONFIG_LINKS= \
      /bin/sh config.status
    config.status: creating config.h
    config.status: config.h is unchanged

on every rebuild.  This seems to have changed due to an autoconf
upgrade at some point in the past.  In the autoconf gdb uses now, it
works to use AC_CONFIG_HEADERS and then create the stamp file via the
"commands" argument.

This patch also fixes up Makefile.in to use the new-style
config.status invocation.  It's no longer necessary to pass the output
file names via environment variables.

gdb/ChangeLog
2019-10-17  Tom Tromey  <tromey@adacore.com>

	* configure: Rebuild.
	* configure.ac: Use AC_CONFIG_HEADERS.  Create stamp-h there, not
	in AC_CONFIG_FILES invocation.
	* Makefile.in (Makefile, data-directory/Makefile, stamp-h): Use
	new-style config.status invocation.

gdb/gdbserver/ChangeLog
2019-10-17  Tom Tromey  <tromey@adacore.com>

	* configure: Rebuild.
	* configure.ac: Use AC_CONFIG_HEADERS.  Create stamp-h there, not
	in AC_CONFIG_FILES invocation.
	* Makefile.in (stamp-h, Makefile): Use new-style config.status
	invocation.

Change-Id: Ia0530d1c5b9756812d29ddb8dc1062326155e61e
2019-10-17 13:21:24 -06:00
2d41fa1165 Move gdb-dlfcn.[ch] to gdbsupport/
I need to use 'gdb_dlopen' inside 'gdbsupport/', but it's not yet
supported there.  This commit moves 'gdb-dlfcn.[ch]' to 'gdbsupport/',
which makes it available also on gdbserver.

gdb/ChangeLog:
2019-08-23  Sergio Durigan Junior  <sergiodj@redhat.com>

	* configure.ac: Don't check for 'dlfcn.h' (moved to
	gdbsupport/common.m4).
	* Makefile.in (COMMON_SFILES): Move 'gdb-dlfcn.c' to
	'gdbsupport/'.
	(HFILES_NO_SRCDIR): Likewise, for 'gdb-dlfcn.h'.
	* compile/compile-c-support.c: Include
	'gdbsupport/gdb-dlfcn.h'.
	* gdbsupport/common.m4: Check for 'dlfcn.h'.
	* gdb-dlfcn.c: Move to...
	* gdbsupport/gdb-dlfcn.c: ... here.
	* gdb-dlfcn.h: Move to...
	* gdbsupport/gdb-dlfcn.h: ... here.

gdb/gdbserver/ChangeLog:
2019-08-23  Sergio Durigan Junior  <sergiodj@redhat.com>

	* Makefile.in (SFILES): Add 'gdbsupport/gdb-dlfcn.c'.
	(OBS): Add 'gdbsupport/gdb-dlfcn.o'.
	* config.in: Regenerate.
	* configure: Regenerate.
2019-08-23 13:13:18 -04:00
d806ea2d0e Add Rust support to source highlighting
Currently, no release of GNU Source Highlight supports Rust.  However,
I've checked in a patch to do so there, and I plan to make a new
release sometime this summer.

This patch prepares gdb for that by adding support for Rust to the
source highlighting code.

Because Source Highlight will throw an exception if the language is
unrecognized, this also changes gdb to ignore exceptions here.  This
will cause gdb to fall back to un-highlighted source text.

This updates gdb's configure script to reject the combination of
Source Highlight and -static-libstdc++.  This is done because it's not
possible to use -static-libstdc++ and then catch exceptions from a
shared library.

Tested with the current and development versions of Source Highlight.

gdb/ChangeLog
2019-08-19  Tom Tromey  <tom@tromey.com>

	* configure: Rebuild.
	* configure.ac: Disallow the combination of -static-libstdc++ and
	source highlight.
	* source-cache.c (get_language_name): Handle rust.
	(source_cache::get_source_lines): Ignore highlighting exceptions.
2019-08-19 10:17:27 -06:00