This patch handles DW_LLE_base_addressx, DW_LLE_startx_length and
DW_LLE_start_length.
Tested by running the testsuite before and after the patch and there is
no increase in the number of test cases that fails. Tested with both
-gdwarf-4 and -gdwarf-5 flags. Also tested -gslit-dwarf along with
-gdwarf-4 as well as -gdwarf5 flags.
This is an effort to support DWARF5 in gdb.
gdb/ChangeLog:
* dwarf2loc.c (decode_debug_loclists_addresses): Handle
DW_LLE_base_addressx, DW_LLE_startx_length, DW_LLE_start_length.
In post_create_inferior, we get the current thread using the
inferior_thread function and store it in `thr`. We then call
get_current_regcache immediately after, which does:
return get_thread_regcache (inferior_thread ());
This patch makes post_create_inferior use get_thread_regcache, passing
`thr`, saving an unnecessary inferior_thread call.
gdb/ChangeLog:
* infcmd.c (post_create_inferior): Use get_thread_regcache
instead of get_current_regcache.
PR symtab/12535 points out that gdb.decode_line("") will cause a
valgrind report.
I think the empty linespec does not really make sense. So, this patch
changes gdb.decode_line to treat a whitespace-only linespec the same
as a non-existing argument.
gdb/ChangeLog
2020-01-14 Tom Tromey <tom@tromey.com>
PR symtab/12535:
* python/python.c (gdbpy_decode_line): Treat empty string the same
as no argument.
gdb/testsuite/ChangeLog
2020-01-14 Tom Tromey <tom@tromey.com>
PR symtab/12535:
* gdb.python/python.exp: Test decode_line with empty string
argument.
Change-Id: I1d95812b4b7a21d69a3e9afd05b9e3141a931897
I noticed that gdb includes libiberty twice in its link line. I don't
think there's a need for this, so this patch removes one of the
references.
gdb/ChangeLog
2020-01-14 Tom Tromey <tom@tromey.com>
* Makefile.in (CLIBS): Remove second use of $(LIBIBERTY).
Change-Id: I43bb7100660867081f937c67ea70ff751c62bbfb
This removes the use of <config.h> from the files in gdb/nat/.
gdb/ChangeLog
2020-01-14 Tom Tromey <tom@tromey.com>
* nat/linux-btrace.c: Don't include <config.h>.
* nat/linux-ptrace.c: Don't include <config.h>.
* nat/x86-linux-dregs.c: Don't include <config.h>.
Change-Id: Ie8c734c54ada848aa020c77ec727704d367eff81
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
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
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
Simon pointed out that the indentation in common.m4 is off. This
patch fixes the problem.
gdb/ChangeLog
2020-01-14 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
* gdbsupport/common.m4 (GDB_AC_COMMON): Fix indentation.
gdb/gdbserver/ChangeLog
2020-01-14 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
Change-Id: I6a629bd5873cca95ba3e17656f0d0ce583a08361
Previously always the outermost function block was used, but
since skip is now able to skip over inline functions it is more
natural to skip the inline function that the program is currently
executing.
gdb:
2020-01-14 Bernd Edlinger <bernd.edlinger@hotmail.de>
* skip.c (skip_function_command): Make skip w/o arguments use the
name of the inlined function if pc is inside any inlined function.
gdb/testsuite:
2020-01-14 Bernd Edlinger <bernd.edlinger@hotmail.de>
* gdb.base/skip-inline.exp: Extend test.
While doing some investigation of mine, i noticed a few typos,
inaccuracies and missing information.
I went ahead and updated/improved those.
gdb/ChangeLog:
2020-01-14 Luis Machado <luis.machado@linaro.org>
* inf-ptrace.c (inf_ptrace_target::resume): Update comments.
* infrun.c (resume_1): Likewise.
(handle_inferior_event): Remove stale comment.
* linux-nat.c (linux_nat_target::resume): Update comments.
(save_stop_reason): Likewise.
(linux_nat_filter_event): Likewise.
* linux-nat.h (struct lwp_info) <stop_pc>, <stop_reason>: Likewise.
I ended up debugging a malformed ELF where a section containing
executable code was not correctly marked as allocatable. Before
realising the ELF was corrupted I tried to place a breakpoint on a
symbol in the non-allocatable, executable section, and GDB crashed.
Though trying to debug such an ELF clearly isn't going to go well I
would prefer, as far as possible, that any input, no matter how
corrupted, not crash GDB.
The crash occurs when trying to set a breakpoint on the name of a
function from the corrupted section. GDB converts the symbol to a
symtab_and_line, and looks up a suitable section for this.
The problem is that the section is actually an obj_section, which is
stored in the table within the objfile, and we only initialise this
table for allocatable sections (see add_to_objfile_sections_full in
objfiles.c). So, if the symbol is in a non-allocatable section then
we end up referencing an uninitialised obj_section.
Later we call get_sal_arch on the symtab_and_line, which calls
get_objfile_arch, which uses the objfile from the uninitialised
obj_section, which will be nullptr, at which point GDB crashes.
The fix I propose here is that when we setup the section references on
msymbols, we should check if the bfd_section being referenced is
allocatable or not. If it is not then we should set the section
reference back to the default 0 section (see how MSYMBOL_OBJ_SECTION
and SYMBOL_OBJ_SECTION treat the 0 section index).
With this fix in place GDB no longer crashes. Instead GDB creates the
breakpoint at the non-allocated address, and then fails, with an
error, when it tries to insert the breakpoint.
gdb/ChangeLog:
* elfread.c (record_minimal_symbol): Set section index to 0 for
non-allocatable sections.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/dw2-bad-elf-other.S: New file.
* gdb.dwarf2/dw2-bad-elf.c: New file.
* gdb.dwarf2/dw2-bad-elf.exp: New file.
Change-Id: Ie05436ab4c6a71440304d20ee639dfb021223f8b
Fixes a bug in the DWARF assembler that prevents multiple line tables
from being created in a test. We currently don't initialise a couple
of flags, as a result we will only ever generate one end of file list,
and one end of header, in the first line table. Any additional line
tables will be missing these parts, and will therefore be corrupt.
This fix will be required for a later commit. There should be no
change in the testsuite after this commit.
gdb/testsuite/ChangeLog:
* lib/dwarf.exp (Dwarf::lines): Reset _line_saw_program and
_line_saw_file.
Change-Id: Id7123f217a036f26ee32d608db3064dd43164596
* Process debug_str_offsets section. Handle DW_AT_str_offsets_base attribute and
keep the value in dwarf2_cu.
* Make addr_base field in dwarf2_cu optional to disambiguate 0 value
(absent or present and 0).
* During parsing, there is no guarantee that DW_AT_str_offsets_base and
DW_AT_rnglists_base fields will be processed before the attributes that need
those values for correct computation. So make two passes, on the first one mark
the attributes that depend on *_base attributes and process only the others.
On the second pass, only process the attributes that are marked on the first
pass.
* For string attributes, differentiate between addresses that directly point to
a string and those that point to an offset in debug_str_offsets section.
* There are now two attributes, DW_AT_addr_base and DW_AT_GNU_addr_base to read
address offset base. Likewise, there are two attributes, DW_AT_rnglists_base
and DW_AT_GNU_ranges_base to read ranges base. Since there is no guarantee which
ones the compiler will generate, create helper functions to handle all cases.
Tested with CC=/usr/bin/gcc (version 8.3.0) against master branch (also with
-gsplit-dwarf and -gdwarf-4 flags) and there was no increase in the set of
tests that fails. (gdb still cannot debug a 'hello world' program with DWARF 5,
so for the time being, this is all we care about).
This is part of an effort to support DWARF-5 in gdb.
Since the data held by the `contents` variable is arbitrary binary data,
it should have gdb_byte elements, not char elements. Also, using
gdb::byte_vector is preferable, since it doesn't unnecessarily
zero-initialize the values.
Instead of adding a cast in the call to m_core_vec->core_read_registers,
I have changed core_read_registers' argument to be a gdb_byte* instead
of a char*.
gdb/ChangeLog:
* gdbcore.h (struct core_fns) <core_read_registers>: Change
core_reg_sect type to gdb_byte *.
* arm-nbsd-nat.c (fetch_elfcore_registers): Likewise.
* cris-tdep.c (fetch_core_registers): Likewise.
* corelow.c (core_target::get_core_register_section): Change
type of `contents` to gdb::byte_vector.
In tui-wingeneral.c:box_win () a comment suggest we should display
titles like this:
+-WINDOW TITLE GOES HERE-+
However, we actually display them like this:
+--WINDOW TITLE GOES HERE+
The former seems nicer to me, so that's what this commit does. Short
titles will appear as:
+-SHORT TITLE------------+
We previously didn't test the horizontal windows borders in the test
suite, however, I've updated things so that we do now check for the
'+-' and '-+' on the upper border, this will give us some protection.
gdb/ChangeLog:
* tui/tui-wingeneral.c (box_win): Position the title in the center
of the border.
gdb/testsuite/ChangeLog:
* lib/tuiterm.exp (Term::_check_box): Check some parts of the top
border.
Change-Id: Iead6910e3b4e68bdf6871f861f23d2efd699faf0
As I was trying to compile gdb for an m68k host, I got this error:
CXX corelow.o
In file included from /binutils-gdb/gdb/gdbsupport/common-defs.h:120,
from /binutils-gdb/gdb/defs.h:28,
from /binutils-gdb/gdb/corelow.c:20:
/binutils-gdb/gdb/corelow.c: In member function 'void core_target::get_core_register_section(regcache*, const regset*, const char*, int, int, const char*, bool)':
/binutils-gdb/gdb/../include/libiberty.h:727:36: error: 'alloca' bound is unknown [-Werror=alloca-larger-than=]
727 | # define alloca(x) __builtin_alloca(x)
| ~~~~~~~~~~~~~~~~^~~
/binutils-gdb/gdb/corelow.c:625:23: note: in expansion of macro 'alloca'
625 | contents = (char *) alloca (size);
| ^~~~~~
We are using alloca to hold the contents of a the core register
sections. These sections are typically fairly small, but there is no
realy guarantee, so I think it would be more reasonable to just use
dynamic allocation here.
gdb/ChangeLog:
* corelow.c (core_target::get_core_register_section): Use
std::vector instead of alloca.
The dat files in regformats/i386 were removed a while ago, this rule is
no longer necessary.
gdb/gdbserver/ChangeLog:
* Makefile.in (%-generated.c): Remove rule for files from
regformats/i386.
Now that most warnings of this kind are fixed, we can enable
-Wmissing-declarations. I say "most", because it is likely that there
are some more in some configurations I am not able to build, but they
should be pretty easy to fix.
gdb/ChangeLog:
* warning.m4: Add -Wmissing-declarations to build_warnings.
* configure: Re-generate.
gdb/gdbserver/ChangeLog:
* configure: Re-generate.
Change-Id: Iae9b59f22eb5dd1965d09f34c5c9e212cddf67ba
Fixing the -Wmissing-declarations errors in gdbserver's tracepoint.c is
a bit tricky, because some functions are compiled for both gdbserver, in
which case they should be static, since they are only used in that file,
and for libinproctrace.so, in which case they should be externally
visible, since they need to be looked up. In the case where they are
externally visible, -Wmissing-declarations requires that a declaration
exists (that's the point of the warning).
I've reused the IP_AGENT_EXPORT_FUNC macro to mark the functions as
static when compiled for gdbserver. Some seemingly unnecessary
declarations are added for when compiling libinproctrace.so (thanks to
Tom for the suggestion).
gdb/gdbserver/ChangeLog:
* tracepoint.h (IP_AGENT_EXPORT_FUNC) [!IN_PROCESS_AGENT]:
Define to static.
* tracepoint.c (stop_tracing, flush_trace_buffer,
about_to_request_buffer_space, get_trace_state_variable_value,
set_trace_state_variable_value, gdb_collect): Add declaration.
Change-Id: If9c66151bd00c3b9c5caa27a7c21c5a3a952de2a
These functions are only used in this file, so should be static.
gdb/gdbserver/ChangeLog:
* linux-x86-low.c (x86_linux_regs_info, amd64_emit_eq_goto,
amd64_emit_ne_goto, amd64_emit_lt_goto, amd64_emit_le_goto,
amd64_emit_gt_goto, amd64_emit_ge_goto, amd64_emit_ge_goto,
i386_emit_eq_goto, i386_emit_ne_goto, i386_emit_lt_goto,
i386_emit_le_goto, i386_emit_gt_goto, i386_emit_ge_goto): Make
static.
Change-Id: I703da41867735aefadd49140e80cd60f6ab9ad39
So that the definitions of get_inferior_cwd/set_inferior_cwd see their
declarations.
CXX inferiors.o
/home/smarchi/src/binutils-gdb/gdb/gdbserver/inferiors.c: In function ‘const char* get_inferior_cwd()’:
/home/smarchi/src/binutils-gdb/gdb/gdbserver/inferiors.c:228:1: error: no previous declaration for ‘const char* get_inferior_cwd()’ [-Werror=missing-declarations]
get_inferior_cwd ()
^~~~~~~~~~~~~~~~
/home/smarchi/src/binutils-gdb/gdb/gdbserver/inferiors.c: In function ‘void set_inferior_cwd(const char*)’:
/home/smarchi/src/binutils-gdb/gdb/gdbserver/inferiors.c:236:1: error: no previous declaration for ‘void set_inferior_cwd(const char*)’ [-Werror=missing-declarations]
set_inferior_cwd (const char *cwd)
^~~~~~~~~~~~~~~~
gdb/gdbserver/ChangeLog:
* inferiors.c: Include gdbsupport/common-inferior.h.
Change-Id: Iae5ccb3e1dc37ce79f03f08465f603a0411e7af0
... so that the definition of hostio_last_error_from_errno in hostio-errno.c
sees the declaration in hostio.h.
Fix this error:
CXX hostio-errno.o
/home/smarchi/src/binutils-gdb/gdb/gdbserver/hostio-errno.c: In function ‘void hostio_last_error_from_errno(char*)’:
/home/smarchi/src/binutils-gdb/gdb/gdbserver/hostio-errno.c:28:1: error: no previous declaration for ‘void hostio_last_error_from_errno(char*)’ [-Werror=missing-declarations]
hostio_last_error_from_errno (char *buf)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
gdb/gdbserver/ChangeLog:
* hostio-errno.c: Include hostio.h.
Change-Id: I056308fd4ce12810d0a1b826c423bd0c7eeb8944
When I try to enable -Wmissing-declarations, I get this error:
CXX python/python.o
/home/smarchi/src/binutils-gdb/gdb/python/python.c: In function ‘PyObject* init__gdb_module()’:
/home/smarchi/src/binutils-gdb/gdb/python/python.c:1582:1: error: no previous declaration for ‘PyObject* init__gdb_module()’ [-Werror=missing-declarations]
init__gdb_module (void)
^~~~~~~~~~~~~~~~
Prevent it by providing a declaration just before the definition.
gdb/ChangeLog:
* python/python.c (init__gdb_module): Add declaration.
Change-Id: I394bc691b7db624708cc4cb2cda28a56ab85a82b
When compiling gdbserver for an architecture that uses the regdat.sh
script (such as m68k) and the -Wmissing-declarations compiler flag, I
get:
REGDAT reg-m68k-generated.c
CXX reg-m68k.o
reg-m68k-generated.c:30:1: error: no previous declaration for 'void init_registers_m68k()' [-Werror=missing-declarations]
30 | init_registers_m68k (void)
| ^~~~~~~~~~~~~~~~~~~
The same happens with other architectures, such as s390, but I'll be
using 68k as an example.
The init_registers_m68k function is defined in reg-m68k-generated.c,
which is produced by the regformats/regdat.sh script. This script reads
the regformats/reg-m68k.dat file, containing a register description, and
produces C code that creates a corresponding target description at
runtime.
The init_registers_m68k function is invoked at initialization time in
linux-m68k-low.c. The function must therefore be non-static, but does
not have a declaration at the moment.
The real clean way of fixing this would be to make regdat.sh generate a
.h file (in addition to the .c file) with declarations for whatever is
in the .c file. The generated .c file would include the .h file, and
therefore the definition would have a corresponding declaration. The
linux-m68k-low.c file would also include this .h file, instead of having
its own declaration of init_registers_m68k, like it does now.
However, this would be a quite big change for not much gain. As far as
I understand, some common architectures (i386, x86-64, ARM, AArch64)
have been moved to dynamically building target descriptions based on
features (the linux-*-tdesc.c files in gdbserver) and don't use
regdat.sh anymore. Logically (and given infinite development
resources), the other architectures would be migrated to this system too
and the regdat.sh script would be dropped. A new architecture would
probably not use regdat.sh either. So I therefore propose this simpler
patch instead, which just adds a local declaration in the generated
file.
gdb/ChangeLog:
* regformats/regdat.sh: Generate declaration for init function.
The intent of the rules modified by this patch is that the *-generated.c
files generated by regdat.sh are re-generated in the event that
regdat.sh is modified. However, if I build, touch regdat.sh, and build
again, the files are not re-generated during the second build.
This is because regdat.sh is specified as an order-only dependency [1],
after the pipe. Make therefore only ensures that regdat.sh exists
before generating the target file, it doesn't check the timestamp of
regdat.sh.
This patch changes it to be a regular prerequisite.
The rules use the $< variable, which is substituted by the first
prerequisite only, so the command lines won't change.
[1] https://www.gnu.org/software/make/manual/html_node/Prerequisite-Types.html
gdb/gdbserver/ChangeLog:
* Makefile.in (%-generated.c): Make $(regdat_sh) a regular
prerequisite.
The remote-sim.c file doesn't build since the main multi-target patch
(5b6d1e4f, "Multi-target support"), this patch is an attempt to fix it.
I have only build-tested it, so I'm not sure it runs fine, but it should
get us close at least.
I made these functions methods of the gdbsim_target, because they need
to pass the target down to some GDB core functions, like
find_inferior_ptid:
- get_sim_inferior_data_by_ptid (renamed to get_inferior_data_by_ptid)
- gdbsim_resume_inferior (renamed to resume_one_inferior)
- gdbsim_close_inferior (renamed to close_one_inferior)
In the last two, I changed iterate_over_inferiors to a range-based for,
since that gives simpler code (no need to pass data through the void
pointer).
The next_pid variable, INITIAL_PID macro and sim_inferior_data structure
are simply moved up in the file, above gdbsim_target.
gdb/ChangeLog:
* remote-sim.c (next_pid, INITIAL_PID, sim_inferior_data): Move
up.
(gdbsim_target) <get_inferior_data_by_ptid, resume_one_inferior,
close_one_inferior>: New methods.
(get_sim_inferior_data_by_ptid): Move to gdbsim_target,
pass down target to find_inferior_pid.
(gdbsim_target::fetch_registers, gdbsim_target::store_registers):
Pass down target to find_inferior_ptid.
(gdbsim_target::create_inferior): Pass down target to
add_thread_silent.
(gdbsim_close_inferior): Move to gdbsim_close_inferior, pass
target down to find_inferior_ptid and switch_to_thread.
(gdbsim_target::close): Update to call close_one_inferior.
(struct resume_data): Remove.
(gdbsim_resume_inferior): Move to gdbsim_target. Take arguments
directly, rather than through a void pointer.
(gdbsim_target::resume): Update to call resume_one_inferior.
When building for mingw with -Wmissing-declarations, I get:
CXX gdbsupport/gdb_wait.o
/binutils-gdb/gdb/gdbsupport/gdb_wait.c:52:1: error: no previous declaration for 'int windows_status_to_termsig(long unsigned int)' [-Wer
ror=missing-declarations]
52 | windows_status_to_termsig (unsigned long status)
| ^~~~~~~~~~~~~~~~~~~~~~~~~
Make gdb_wait.c include gdb_wait.h to fix it.
gdb/ChangeLog:
* gdbsupport/gdb_wait.c: Include gdb_wait.h.
When building with -Wmissing-declarations, I get:
CXX linux-arm-tdesc.o
/binutils-gdb/gdb/gdbserver/linux-arm-tdesc.c:29:1: error: no previous declaration for 'const target_desc* arm_linux_read_description(arm_fp_type)' [-Werror=missing-declarations]
29 | arm_linux_read_description (arm_fp_type fp_type)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
/binutils-gdb/gdb/gdbserver/linux-arm-tdesc.c:49:1: error: no previous declaration for 'arm_fp_type arm_linux_get_tdesc_fp_type(const target_desc*)' [-Werror=missing-declarations]
49 | arm_linux_get_tdesc_fp_type (const target_desc *tdesc)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
Include linux-arm-tdesc.h in linux-arm-tdesc.c to fix it. And because
linux-arm-tdesc.h uses the arm_fp_type, it should include arch/arm.h as
well.
gdb/gdbserver/ChangeLog:
* linux-arm-tdesc.c: Include linux-arm-tdesc.h.
* linux-arm-tdesc.h: Include arch/arm.h.
This function is only used in this file, so make it static. It fixes
this error, when building with -Wmissing-declarations:
CXX linux-aarch64-low.o
/home/simark/src/binutils-gdb/gdb/gdbserver/linux-aarch64-low.c:2642:1: error: no previous declaration for 'void aarch64_write_goto_address(CORE_ADDR, CORE_ADDR, int)' [-Werror=missing-declarations]
aarch64_write_goto_address (CORE_ADDR from, CORE_ADDR to, int size)
^~~~~~~~~~~~~~~~~~~~~~~~~~
gdb/gdbserver/ChangeLog:
* linux-aarch64-low.c (aarch64_write_goto_address): Make static.
When building gdbserver for an aarch64 host with -Wmissing-declarations,
I see:
CXX linux-aarch32-tdesc.o
/home/simark/src/binutils-gdb/gdb/gdbserver/linux-aarch32-tdesc.c:28:1: error: no previous declaration for 'const target_desc* aarch32_linux_read_description()' [-Werror=missing-declarations]
aarch32_linux_read_description ()
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/simark/src/binutils-gdb/gdb/gdbserver/linux-aarch32-tdesc.c:43:1: error: no previous declaration for 'bool is_aarch32_linux_description(const target_desc*)' [-Werror=missing-declarations]
is_aarch32_linux_description (const target_desc *tdesc)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
CXX linux-aarch64-tdesc.o
/home/simark/src/binutils-gdb/gdb/gdbserver/linux-aarch64-tdesc.c:32:1: error: no previous declaration for 'const target_desc* aarch64_linux_read_description(uint64_t, bool)' [-Werror=missing-declarations]
aarch64_linux_read_description (uint64_t vq, bool pauth_p)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix it by including linux-aarch32-tdesc.h in linux-aarch32-tdesc.c and
linux-aarch64-tdesc.h in linux-aarch64-tdesc.c.
gdb/gdbserver/ChangeLog:
* linux-aarch32-tdesc.c: Include linux-aarch32-tdesc.h.
* linux-aarch64-tdesc.c: Include linux-aarch64-tdesc.h.
The multi-target patch should have removed all traces of
discard_all_inferiors, but somehow one use stayed behind along with
the definition of the function.
discard_all_inferiors is bad now because it blindly exits inferiors of
all target connections. It's best to remove it.
gdb/ChangeLog:
2020-01-12 Pedro Alves <palves@redhat.com>
* bsd-kvm.c (bsd_kvm_target::close): Call exit_inferior_silent
directly for the current inferior instead of
discard_all_inferiors.
(discard_all_inferiors): Delete.
When adding support for styling the TUI borders, I neglected to have
this code check cli_styling. As a result, "set style enabled off"
does not affect the borders.
This patch fixes this oversight. While doing this, I found that
running gdb without an executable, enabling the TUI, and then trying
"set style enabled off" would fail with the mysterious "No registers".
The fix for this is to use deprecated_safe_get_selected_frame in
tui_source_window_base::refill.
gdb/ChangeLog
2020-01-11 Tom Tromey <tom@tromey.com>
* tui/tui-wingeneral.c (box_win): Check cli_styling.
* tui/tui-winsource.c (tui_source_window_base::refill): Use
deprecated_safe_get_selected_frame.
Change-Id: I36acda25dd9014d994d366b4a0e8faee9d95d0f8
GDB uses the 'current_top_target' when displaying the description of
an inferior. This leads to same target being used for each inferior
and, in turn, yields incorrect output when the inferior has a target
that is supposed to give a specialized output. For instance, the
remote target outputs "Remote target" instead of "process XYZ" as the
description if the multi-process feature is not supported or turned
off.
E.g.: Suppose we have a native and a remote target, and the native is
the current inferior. The remote target does not support multi-process.
For "info inferiors", we would expect to see:
~~~
(gdb) i inferiors
Num Description Connection Executable
* 1 process 29060 1 (native) /a/path
2 Remote target 2 (remote ...)
~~~
but instead we get
~~~
(gdb) i inferiors
Num Description Connection Executable
* 1 process 29060 1 (native) /a/path
2 process 42000 2 (remote ...)
~~~
Similarly, if the current inferior is the remote one, we would expect
to see
~~~
(gdb) i inferiors
Num Description Connection Executable
1 process 29060 1 (native) /a/path
* 2 Remote target 2 (remote ...)
~~~
but we get
~~~
(gdb) i inferiors
Num Description Connection Executable
* 1 Remote target 1 (native) /a/path
2 Remote target 2 (remote ...)
~~~
With this patch, we switch to the inferior when outputting its
description, so that the current_top_target will be aligned to the
inferior we are displaying.
For testing, this patch expands the "info inferiors" test for the
multi-target feature. The test was checking for the output of the
info commands after setup, only when the current inferior is the last
added inferior.
This patch does the following to the testcase:
1. The "info inferiors" and "info connections" test is extracted out
from the "setup" procedure to a separate procedure.
2. The test is enriched to check the output after switching to each
inferior, not just the last one.
3. The test is performed twice; one for when the multi-process feature
is turned on, one for off.
gdb/ChangeLog:
2020-01-10 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* inferior.c (print_inferior): Switch inferior before printing it.
gdb/testsuite/ChangeLog:
2020-01-10 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* gdb.multi/multi-target.exp (setup): Factor out "info
connections" and "info inferiors" tests to ...
(test_info_inferiors): ... this new procedure.
(top level): Run new "info-inferiors" tests.
With multi-target, each inferior now has its own target connection.
The problem in switch_to_program_space_and_thread is that in the
current state GDB switches to "no thread" and also sets the program
space but because the inferior is not switched, potentially an
incorrect target remains selected.
Here is a sample scenario that exploits this flow:
On terminal 1, start a gdbserver on a program named foo:
$ gdbserver :1234 ./foo
On terminal 2, start gdb on a program named bar. Suppose foo and bar
are compiled from foo.c and bar.c. They are completely separate. So,
bar.c:2 has no meaning for foo.
$ gdb -q ./bar
Reading symbols from ./bar...
(gdb) add-inferior
[New inferior 2]
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) target remote :1234
...
(gdb) set debug remote 2
(gdb) break bar.c:2
Sending packet: $Hgp0.0#ad...Packet received: OK
Sending packet: $m5fa,12#f8...Packet received: E01
Sending packet: $m5fa,1#c6...Packet received: E01
Sending packet: $m5fb,3#c9...Packet received: E01
Sending packet: $m5fe,1#ca...Packet received: E01
Breakpoint 1 at 0x5fe: file bar.c, line 2.
(gdb)
Here we have an unnecessary sending of the packets to the gdbserver.
With this fix in progspace-and-thread.c, we'll get this:
(gdb) break bar.c:2
Breakpoint 1 at 0x5fe: file bar.c, line 2.
(gdb)
Now there is no sending of the packets to gdbserver.
The changes around clear_symtab_users calls are necessary because
otherwise we regress gdb.base/step-over-exit.exp, hitting the new
assertion in switch_to_program_space_and_thread. The problem is, a
forked child terminates, and when GDB decides to auto-purge that
inferior, GDB tries to switch to the pspace of that no-longer-existing
inferior.
The root of the problem is within the program_space destructor:
program_space::~program_space ()
{
...
set_current_program_space (this); # (1)
...
breakpoint_program_space_exit (this); # (2)
...
free_all_objfiles (); # (3)
...
}
We get here from delete_inferior -> delete_program_space.
So we're deleting an inferior, and the inferior to be
deleted is no longer in the inferior list.
At (2), we've deleted all the breakpoints and locations for the
program space being deleted.
The crash happens while doing a breakpoint re-set, called by
clear_symtab_users at the tail end of (3). That is, while recreating
breakpoints for the current program space, which is the program space
we're tearing down. During breakpoint re-set, we try to switch to the
new location's pspace (the current pspace set in (1), so the pspace
we're tearing down) with switch_to_program_space_and_thread, and that
hits the failed assertion. It's the fact that we recreate breakpoints
in the program_space destructor that is the latent bug here. Just
don't do that, and we don't end up in the crash situation.
My first approach to fix this added a symfile_add_flags parameter to
program_space::free_all_objfiles, and then passed that down to
clear_symtab_users. The program_space dtor would then pass down
SYMFILE_DEFER_BP_RESET to free_all_objfiles. I couldn't help feeling
that adding that parameter to free_all_objfiles looked a little
awkward, so I settled on something a little different -- hoist the
clear_symtab_users call to the callers. There are only two callers.
I felt that that didn't look as odd, particularly since
remove_symbol_file_command also does:
objf->unlink ();
clear_symtab_users (0);
I.e., objfile deletion is already separate from calling
clear_symtab_users in some places.
gdb/ChangeLog:
2020-01-10 Aleksandar Paunovic <aleksandar.paunovic@intel.com>
Pedro Alves <palves@redhat.com>
* progspace-and-thread.c (switch_to_program_space_and_thread):
Assert there's an inferior for PSPACE. Use
switch_to_inferior_no_thread to switch the inferior too.
* progspace.c (program_space::~program_space): Call
clear_symtab_users here, with SYMFILE_DEFER_BP_RESET.
(program_space::free_all_objfiles): Don't call clear_symtab_users
here.
* symfile.c (symbol_file_clear): Call clear_symtab_users here.
gdb/testsuite/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* gdb.server/bkpt-other-inferior.exp: New file.
This commit documents the new multi-target features in both NEWS and
user manual.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* NEWS: Mention multi-target debugging, "info connections", and
"add-inferior -no-connection".
gdb/doc/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Starting): Say "current inferior not connected"
instead of "GDB not connected".
(Inferiors and Programs): Rename node to ...
(Inferiors Connections and Programs): ... this. Update all
references. Talk about multiple target connections. Update "info
inferiors" info to mention the connections column. Describe "info
connections". Document "add-inferior -no-connection".
* guile.texi, python.texi: Update cross references.
Currently, we can only support resuming multiple targets at the same
time if all targets are in non-stop mode (or user-visible all-stop
mode with target backend in non-stop mode).
This patch makes GDB error out if the user tries to resume more than
one target at the same time and one of the resumed targets isn't in
non-stop mode:
(gdb) info inferiors
Num Description Connection Executable
1 process 15303 1 (native) a.out
* 2 process 15286 2 (extended-remote :9999) a.out
(gdb) set schedule-multiple on
(gdb) c
Continuing.
Connection 2 (extended-remote :9999) does not support multi-target resumption.
This is here later in the series instead of in the main multi-target
patch because it depends the previous patch, which added
process_stratum_target::connection_string().
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* infrun.c: Include "target-connection.h".
(check_multi_target_resumption): New.
(proceed): Call it.
* target-connection.c (make_target_connection_string): Make
extern.
* target-connection.h (make_target_connection_string): Declare.
This commit extends the CLI a bit for multi-target, in three ways.
#1 - New "info connections" command.
This is a new command that lists the open connections (process_stratum
targets). For example, if you're debugging two remote connections, a
couple local/native processes, and a core dump, all at the same time,
you might see something like this:
(gdb) info connections
Num What Description
1 remote 192.168.0.1:9999 Remote serial target in gdb-specific protocol
2 remote 192.168.0.2:9998 Remote serial target in gdb-specific protocol
* 3 native Native process
4 core Local core dump file
#2 - New "info inferiors" "Connection" column
You'll also see a new matching "Connection" column in "info
inferiors", showing you which connection an inferior is bound to:
(gdb) info inferiors
Num Description Connection Executable
1 process 18526 1 (remote 192.168.0.1:9999) target:/tmp/a.out
2 process 18531 2 (remote 192.168.0.2:9998) target:/tmp/a.out
3 process 19115 3 (native) /tmp/prog1
4 process 6286 4 (core) myprogram
* 5 process 19122 3 (native) /bin/hello
#3 - Makes "add-inferior" show the inferior's target connection
"add-inferior" now shows you the connection you've just bound the
inferior to, which is the current process_stratum target:
(gdb) add-inferior
[New inferior 2]
Added inferior 2 on connection 1 (extended-remote localhost:2346)
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* Makefile.in (COMMON_SFILES): Add target-connection.c.
* inferior.c (uiout_field_connection): New function.
(print_inferior): Add new "connection-id" column.
(add_inferior_command): Show connection number/string of added
inferior.
* process-stratum-target.h
(process_stratum_target::connection_string): New virtual method.
(process_stratum_target::connection_number): New field.
* remote.c (remote_target::connection_string): New override.
* target-connection.c: New file.
* target-connection.h: New file.
* target.c (decref_target): Remove process_stratum targets from
the connection list.
(target_stack::push): Add process_stratum targets to the
connection list.
gdb/testsuite/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* gdb.base/kill-detach-inferiors-cmd.exp: Adjust expected output
of "add-inferior".
* gdb.base/quit-live.exp: Likewise.
* gdb.base/remote-exec-file.exp: Likewise.
* gdb.guile/scm-progspace.exp: Likewise.
* gdb.linespec/linespec.exp: Likewise.
* gdb.mi/new-ui-mi-sync.exp: Likewise.
* gdb.mi/user-selected-context-sync.exp: Likewise.
* gdb.multi/multi-target.exp (setup): Add "info connection" and
"info inferiors" tests.
* gdb.multi/remove-inferiors.exp: Adjust expected output of
"add-inferior".
* gdb.multi/watchpoint-multi.exp: Likewise.
* gdb.python/py-inferior.exp: Likewise.
* gdb.server/extended-remote-restart.exp: Likewise.
* gdb.threads/fork-plus-threads.exp: Adjust expected output of
"info inferiors".
* gdb.threads/forking-threads-plus-breakpoint.exp: Likewise.
* gdb.trace/report.exp: Likewise.
This commit reverts:
commit 5f5219fc34
Author: Pedro Alves <palves@redhat.com>
AuthorDate: Tue Apr 12 16:49:30 2016 +0100
Remove unused struct serial::name field
The following patches will add uses for the field.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
Revert:
2016-04-12 Pedro Alves <palves@redhat.com>
* serial.c (serial_open, serial_fdopen_ops, do_serial_close):
Remove references to name.
* serial.h (struct serial) <name>: Delete.
Since each inferior has its own target stack, the stratum condition
for the "error out if debugging something" check is always false.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* gdbarch-selftests.c (register_to_value_test): Remove "target
already pushed" check.
This adds a testcase exercising multi-target features. It spawns 6
inferiors, like this:
inferior 1 -> native
inferior 2 -> extended-remote 1
inferior 3 -> core
inferior 4 -> native
inferior 5 -> extended-remote 2
inferior 6 -> core
and then tests various details, including:
- running to breakpoints
- interrupting with Ctrl-C and "interrupt -a"
- "next" bouncing between two breakpoints in two threads running in
different targets.
- since we have cores and live inferiors mixed in the same session,
this makes sure that gdb doesn't try to remove a core dump's
threads.
- all-stop and non-stop modes.
This testcase caught a _lot_ of bugs in development.
gdb/testsuite/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* gdb.multi/multi-target.c: New file.
* gdb.multi/multi-target.exp: New file.
* lib/gdbserver-support.exp (gdb_target_cmd): Handle "Non-stop
mode requested, but remote does not support non-stop".
This commit adds multi-target support to GDB. What this means is that
with this commit, GDB can now be connected to different targets at the
same time. E.g., you can debug a live native process and a core dump
at the same time, connect to multiple gdbservers, etc.
Actually, the word "target" is overloaded in gdb. We already have a
target stack, with pushes several target_ops instances on top of one
another. We also have "info target" already, which means something
completely different to what this patch does.
So from here on, I'll be using the "target connections" term, to mean
an open process_stratum target, pushed on a target stack. This patch
makes gdb have multiple target stacks, and multiple process_stratum
targets open simultaneously. The user-visible changes / commands will
also use this terminology, but of course it's all open to debate.
User-interface-wise, not that much changes. The main difference is
that each inferior may have its own target connection.
A target connection (e.g., a target extended-remote connection) may
support debugging multiple processes, just as before.
Say you're debugging against gdbserver in extended-remote mode, and
you do "add-inferior" to prepare to spawn a new process, like:
(gdb) target extended-remote :9999
...
(gdb) start
...
(gdb) add-inferior
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) file a.out
...
(gdb) start
...
At this point, you have two inferiors connected to the same gdbserver.
With this commit, GDB will maintain a target stack per inferior,
instead of a global target stack.
To preserve the behavior above, by default, "add-inferior" makes the
new inferior inherit a copy of the target stack of the current
inferior. Same across a fork - the child inherits a copy of the
target stack of the parent. While the target stacks are copied, the
targets themselves are not. Instead, target_ops is made a
refcounted_object, which means that target_ops instances are
refcounted, which each inferior counting for a reference.
What if you want to create an inferior and connect it to some _other_
target? For that, this commit introduces a new "add-inferior
-no-connection" option that makes the new inferior not share the
current inferior's target. So you could do:
(gdb) target extended-remote :9999
Remote debugging using :9999
...
(gdb) add-inferior -no-connection
[New inferior 2]
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) info inferiors
Num Description Executable
1 process 18401 target:/home/pedro/tmp/main
* 2 <null>
(gdb) tar extended-remote :10000
Remote debugging using :10000
...
(gdb) info inferiors
Num Description Executable
1 process 18401 target:/home/pedro/tmp/main
* 2 process 18450 target:/home/pedro/tmp/main
(gdb)
A following patch will extended "info inferiors" to include a column
indicating which connection an inferior is bound to, along with a
couple other UI tweaks.
Other than that, debugging is the same as before. Users interact with
inferiors and threads as before. The only difference is that
inferiors may be bound to processes running in different machines.
That's pretty much all there is to it in terms of noticeable UI
changes.
On to implementation.
Since we can be connected to different systems at the same time, a
ptid_t is no longer a unique identifier. Instead a thread can be
identified by a pair of ptid_t and 'process_stratum_target *', the
later being the instance of the process_stratum target that owns the
process/thread. Note that process_stratum_target inherits from
target_ops, and all process_stratum targets inherit from
process_stratum_target. In earlier patches, many places in gdb were
converted to refer to threads by thread_info pointer instead of
ptid_t, but there are still places in gdb where we start with a
pid/tid and need to find the corresponding inferior or thread_info
objects. So you'll see in the patch many places adding a
process_stratum_target parameter to functions that used to take only a
ptid_t.
Since each inferior has its own target stack now, we can always find
the process_stratum target for an inferior. That is done via a
inf->process_target() convenience method.
Since each inferior has its own target stack, we need to handle the
"beneath" calls when servicing target calls. The solution I settled
with is just to make sure to switch the current inferior to the
inferior you want before making a target call. Not relying on global
context is just not feasible in current GDB. Fortunately, there
aren't that many places that need to do that, because generally most
code that calls target methods already has the current context
pointing to the right inferior/thread. Note, to emphasize -- there's
no method to "switch to this target stack". Instead, you switch the
current inferior, and that implicitly switches the target stack.
In some spots, we need to iterate over all inferiors so that we reach
all target stacks.
Native targets are still singletons. There's always only a single
instance of such targets.
Remote targets however, we'll have one instance per remote connection.
The exec target is still a singleton. There's only one instance. I
did not see the point of instanciating more than one exec_target
object.
After vfork, we need to make sure to push the exec target on the new
inferior. See exec_on_vfork.
For type safety, functions that need a {target, ptid} pair to identify
a thread, take a process_stratum_target pointer for target parameter
instead of target_ops *. Some shared code in gdb/nat/ also need to
gain a target pointer parameter. This poses an issue, since gdbserver
doesn't have process_stratum_target, only target_ops. To fix this,
this commit renames gdbserver's target_ops to process_stratum_target.
I think this makes sense. There's no concept of target stack in
gdbserver, and gdbserver's target_ops really implements a
process_stratum-like target.
The thread and inferior iterator functions also gain
process_stratum_target parameters. These are used to be able to
iterate over threads and inferiors of a given target. Following usual
conventions, if the target pointer is null, then we iterate over
threads and inferiors of all targets.
I tried converting "add-inferior" to the gdb::option framework, as a
preparatory patch, but that stumbled on the fact that gdb::option does
not support file options yet, for "add-inferior -exec". I have a WIP
patchset that adds that, but it's not a trivial patch, mainly due to
need to integrate readline's filename completion, so I deferred that
to some other time.
In infrun.c/infcmd.c, the main change is that we need to poll events
out of all targets. See do_target_wait. Right after collecting an
event, we switch the current inferior to an inferior bound to the
target that reported the event, so that target methods can be used
while handling the event. This makes most of the code transparent to
multi-targets. See fetch_inferior_event.
infrun.c:stop_all_threads is interesting -- in this function we need
to stop all threads of all targets. What the function does is send an
asynchronous stop request to all threads, and then synchronously waits
for events, with target_wait, rinse repeat, until all it finds are
stopped threads. Now that we have multiple targets, it's not
efficient to synchronously block in target_wait waiting for events out
of one target. Instead, we implement a mini event loop, with
interruptible_select, select'ing on one file descriptor per target.
For this to work, we need to be able to ask the target for a waitable
file descriptor. Such file descriptors already exist, they are the
descriptors registered in the main event loop with add_file_handler,
inside the target_async implementations. This commit adds a new
target_async_wait_fd target method that just returns the file
descriptor in question. See wait_one / stop_all_threads in infrun.c.
The 'threads_executing' global is made a per-target variable. Since
it is only relevant to process_stratum_target targets, this is where
it is put, instead of in target_ops.
You'll notice that remote.c includes some FIXME notes. These refer to
the fact that the global arrays that hold data for the remote packets
supported are still globals. For example, if we connect to two
different servers/stubs, then each might support different remote
protocol features. They might even be different architectures, like
e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a
host/controller scenario as a single program. That isn't going to
work correctly today, because of said globals. I'm leaving fixing
that for another pass, since it does not appear to be trivial, and I'd
rather land the base work first. It's already useful to be able to
debug multiple instances of the same server (e.g., a distributed
cluster, where you have full control over the servers installed), so I
think as is it's already reasonable incremental progress.
Current limitations:
- You can only resume more that one target at the same time if all
targets support asynchronous debugging, and support non-stop mode.
It should be possible to support mixed all-stop + non-stop
backends, but that is left for another time. This means that
currently in order to do multi-target with gdbserver you need to
issue "maint set target-non-stop on". I would like to make that
mode be the default, but we're not there yet. Note that I'm
talking about how the target backend works, only. User-visible
all-stop mode works just fine.
- As explained above, connecting to different remote servers at the
same time is likely to produce bad results if they don't support the
exact set of RSP features.
FreeBSD updates courtesy of John Baldwin.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
John Baldwin <jhb@FreeBSD.org>
* aarch64-linux-nat.c
(aarch64_linux_nat_target::thread_architecture): Adjust.
* ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call.
(task_command_1): Likewise.
* aix-thread.c (sync_threadlists, aix_thread_target::resume)
(aix_thread_target::wait, aix_thread_target::fetch_registers)
(aix_thread_target::store_registers)
(aix_thread_target::thread_alive): Adjust.
* amd64-fbsd-tdep.c: Include "inferior.h".
(amd64fbsd_get_thread_local_address): Pass down target.
* amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle
thread's gdbarch instead of target_gdbarch.
* break-catch-sig.c (signal_catchpoint_print_it): Adjust call to
get_last_target_status.
* break-catch-syscall.c (print_it_catch_syscall): Likewise.
* breakpoint.c (breakpoints_should_be_inserted_now): Consider all
inferiors.
(update_inserted_breakpoint_locations): Skip if inferiors with no
execution.
(update_global_location_list): When handling moribund locations,
find representative inferior for location's pspace, and use thread
count of its process_stratum target.
* bsd-kvm.c (bsd_kvm_target_open): Pass target down.
* bsd-uthread.c (bsd_uthread_target::wait): Use
as_process_stratum_target and adjust thread_change_ptid and
add_thread calls.
(bsd_uthread_target::update_thread_list): Use
as_process_stratum_target and adjust find_thread_ptid,
thread_change_ptid and add_thread calls.
* btrace.c (maint_btrace_packet_history_cmd): Adjust
find_thread_ptid call.
* corelow.c (add_to_thread_list): Adjust add_thread call.
(core_target_open): Adjust add_thread_silent and thread_count
calls.
(core_target::pid_to_str): Adjust find_inferior_ptid call.
* ctf.c (ctf_target_open): Adjust add_thread_silent call.
* event-top.c (async_disconnect): Pop targets from all inferiors.
* exec.c (add_target_sections): Push exec target on all inferiors
sharing the program space.
(remove_target_sections): Remove the exec target from all
inferiors sharing the program space.
(exec_on_vfork): New.
* exec.h (exec_on_vfork): Declare.
* fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter.
Pass it down.
(fbsd_nat_target::update_thread_list): Adjust.
(fbsd_nat_target::resume): Adjust.
(fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it
down.
(fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust.
* fbsd-tdep.c (fbsd_corefile_thread): Adjust
get_thread_arch_regcache call.
* fork-child.c (gdb_startup_inferior): Pass target down to
startup_inferior and set_executing.
* gdbthread.h (struct process_stratum_target): Forward declare.
(add_thread, add_thread_silent, add_thread_with_info)
(in_thread_list): Add process_stratum_target parameter.
(find_thread_ptid(inferior*, ptid_t)): New overload.
(find_thread_ptid, thread_change_ptid): Add process_stratum_target
parameter.
(all_threads()): Delete overload.
(all_threads, all_non_exited_threads): Add process_stratum_target
parameter.
(all_threads_safe): Use brace initialization.
(thread_count): Add process_stratum_target parameter.
(set_resumed, set_running, set_stop_requested, set_executing)
(threads_are_executing, finish_thread_state): Add
process_stratum_target parameter.
(switch_to_thread): Use is_current_thread.
* i386-fbsd-tdep.c: Include "inferior.h".
(i386fbsd_get_thread_local_address): Pass down target.
* i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust.
* inf-child.c (inf_child_target::maybe_unpush_target): Remove
have_inferiors check.
* inf-ptrace.c (inf_ptrace_target::create_inferior)
(inf_ptrace_target::attach): Adjust.
* infcall.c (run_inferior_call): Adjust.
* infcmd.c (run_command_1): Pass target to
scoped_finish_thread_state.
(proceed_thread_callback): Skip inferiors with no execution.
(continue_command): Rename 'all_threads' local to avoid hiding
'all_threads' function. Adjust get_last_target_status call.
(prepare_one_step): Adjust set_running call.
(signal_command): Use user_visible_resume_target. Compare thread
pointers instead of inferior_ptid.
(info_program_command): Adjust to pass down target.
(attach_command): Mark target's 'thread_executing' flag.
(stop_current_target_threads_ns): New, factored out from ...
(interrupt_target_1): ... this. Switch inferior before making
target calls.
* inferior-iter.h
(struct all_inferiors_iterator, struct all_inferiors_range)
(struct all_inferiors_safe_range)
(struct all_non_exited_inferiors_range): Filter on
process_stratum_target too. Remove explicit.
* inferior.c (inferior::inferior): Push dummy target on target
stack.
(find_inferior_pid, find_inferior_ptid, number_of_live_inferiors):
Add process_stratum_target parameter, and pass it down.
(have_live_inferiors): Adjust.
(switch_to_inferior_and_push_target): New.
(add_inferior_command, clone_inferior_command): Handle
"-no-connection" parameter. Use
switch_to_inferior_and_push_target.
(_initialize_inferior): Mention "-no-connection" option in
the help of "add-inferior" and "clone-inferior" commands.
* inferior.h: Include "process-stratum-target.h".
(interrupt_target_1): Use bool.
(struct inferior) <push_target, unpush_target, target_is_pushed,
find_target_beneath, top_target, process_target, target_at,
m_stack>: New.
(discard_all_inferiors): Delete.
(find_inferior_pid, find_inferior_ptid, number_of_live_inferiors)
(all_inferiors, all_non_exited_inferiors): Add
process_stratum_target parameter.
* infrun.c: Include "gdb_select.h" and <unordered_map>.
(target_last_proc_target): New global.
(follow_fork_inferior): Push target on new inferior. Pass target
to add_thread_silent. Call exec_on_vfork. Handle target's
reference count.
(follow_fork): Adjust get_last_target_status call. Also consider
target.
(follow_exec): Push target on new inferior.
(struct execution_control_state) <target>: New field.
(user_visible_resume_target): New.
(do_target_resume): Call target_async.
(resume_1): Set target's threads_executing flag. Consider resume
target.
(commit_resume_all_targets): New.
(proceed): Also consider resume target. Skip threads of inferiors
with no execution. Commit resumtion in all targets.
(start_remote): Pass current inferior to wait_for_inferior.
(infrun_thread_stop_requested): Consider target as well. Pass
thread_info pointer to clear_inline_frame_state instead of ptid.
(infrun_thread_thread_exit): Consider target as well.
(random_pending_event_thread): New inferior parameter. Use it.
(do_target_wait): Rename to ...
(do_target_wait_1): ... this. Add inferior parameter, and pass it
down.
(threads_are_resumed_pending_p, do_target_wait): New.
(prepare_for_detach): Adjust calls.
(wait_for_inferior): New inferior parameter. Handle it. Use
do_target_wait_1 instead of do_target_wait.
(fetch_inferior_event): Adjust. Switch to representative
inferior. Pass target down.
(set_last_target_status): Add process_stratum_target parameter.
Save target in global.
(get_last_target_status): Add process_stratum_target parameter and
handle it.
(nullify_last_target_wait_ptid): Clear 'target_last_proc_target'.
(context_switch): Check inferior_ptid == null_ptid before calling
inferior_thread().
(get_inferior_stop_soon): Pass down target.
(wait_one): Rename to ...
(poll_one_curr_target): ... this.
(struct wait_one_event): New.
(wait_one): New.
(stop_all_threads): Adjust.
(handle_no_resumed, handle_inferior_event): Adjust to consider the
event's target.
(switch_back_to_stepped_thread): Also consider target.
(print_stop_event): Update.
(normal_stop): Update. Also consider the resume target.
* infrun.h (wait_for_inferior): Remove declaration.
(user_visible_resume_target): New declaration.
(get_last_target_status, set_last_target_status): New
process_stratum_target parameter.
* inline-frame.c (clear_inline_frame_state(ptid_t)): Add
process_stratum_target parameter, and use it.
(clear_inline_frame_state (thread_info*)): New.
* inline-frame.c (clear_inline_frame_state(ptid_t)): Add
process_stratum_target parameter.
(clear_inline_frame_state (thread_info*)): Declare.
* linux-fork.c (delete_checkpoint_command): Pass target down to
find_thread_ptid.
(checkpoint_command): Adjust.
* linux-nat.c (linux_nat_target::follow_fork): Switch to thread
instead of just tweaking inferior_ptid.
(linux_nat_switch_fork): Pass target down to thread_change_ptid.
(exit_lwp): Pass target down to find_thread_ptid.
(attach_proc_task_lwp_callback): Pass target down to
add_thread/set_running/set_executing.
(linux_nat_target::attach): Pass target down to
thread_change_ptid.
(get_detach_signal): Pass target down to find_thread_ptid.
Consider last target status's target.
(linux_resume_one_lwp_throw, resume_lwp)
(linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp)
(stop_wait_callback, save_stop_reason, linux_nat_filter_event)
(linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down.
(linux_nat_target::async_wait_fd): New.
(linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass
target down.
* linux-nat.h (linux_nat_target::async_wait_fd): Declare.
* linux-tdep.c (get_thread_arch_regcache): Pass target down.
* linux-thread-db.c (struct thread_db_info::process_target): New
field.
(add_thread_db_info): Save target.
(get_thread_db_info): New process_stratum_target parameter. Also
match target.
(delete_thread_db_info): New process_stratum_target parameter.
Also match target.
(thread_from_lwp): Adjust to pass down target.
(thread_db_notice_clone): Pass down target.
(check_thread_db_callback): Pass down target.
(try_thread_db_load_1): Always push the thread_db target.
(try_thread_db_load, record_thread): Pass target down.
(thread_db_target::detach): Pass target down. Always unpush the
thread_db target.
(thread_db_target::wait, thread_db_target::mourn_inferior): Pass
target down. Always unpush the thread_db target.
(find_new_threads_callback, thread_db_find_new_threads_2)
(thread_db_target::update_thread_list): Pass target down.
(thread_db_target::pid_to_str): Pass current inferior down.
(thread_db_target::get_thread_local_address): Pass target down.
(thread_db_target::resume, maintenance_check_libthread_db): Pass
target down.
* nto-procfs.c (nto_procfs_target::update_thread_list): Adjust.
* procfs.c (procfs_target::procfs_init_inferior): Declare.
(proc_set_current_signal, do_attach, procfs_target::wait): Adjust.
(procfs_init_inferior): Rename to ...
(procfs_target::procfs_init_inferior): ... this and adjust.
(procfs_target::create_inferior, procfs_notice_thread)
(procfs_do_thread_registers): Adjust.
* ppc-fbsd-tdep.c: Include "inferior.h".
(ppcfbsd_get_thread_local_address): Pass down target.
* proc-service.c (ps_xfer_memory): Switch current inferior and
program space as well.
(get_ps_regcache): Pass target down.
* process-stratum-target.c
(process_stratum_target::thread_address_space)
(process_stratum_target::thread_architecture): Pass target down.
* process-stratum-target.h
(process_stratum_target::threads_executing): New field.
(as_process_stratum_target): New.
* ravenscar-thread.c
(ravenscar_thread_target::update_inferior_ptid): Pass target down.
(ravenscar_thread_target::wait, ravenscar_add_thread): Pass target
down.
* record-btrace.c (record_btrace_target::info_record): Adjust.
(record_btrace_target::record_method)
(record_btrace_target::record_is_replaying)
(record_btrace_target::fetch_registers)
(get_thread_current_frame_id, record_btrace_target::resume)
(record_btrace_target::wait, record_btrace_target::stop): Pass
target down.
* record-full.c (record_full_wait_1): Switch to event thread.
Pass target down.
* regcache.c (regcache::regcache)
(get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add
process_stratum_target parameter and handle it.
(current_thread_target): New global.
(get_thread_regcache): Add process_stratum_target parameter and
handle it. Switch inferior before calling target method.
(get_thread_regcache): Pass target down.
(get_thread_regcache_for_ptid): Pass target down.
(registers_changed_ptid): Add process_stratum_target parameter and
handle it.
(registers_changed_thread, registers_changed): Pass target down.
(test_get_thread_arch_aspace_regcache): New.
(current_regcache_test): Define a couple local test_target_ops
instances and use them for testing.
(readwrite_regcache): Pass process_stratum_target parameter.
(cooked_read_test, cooked_write_test): Pass mock_target down.
* regcache.h (get_thread_regcache, get_thread_arch_regcache)
(get_thread_arch_aspace_regcache): Add process_stratum_target
parameter.
(regcache::target): New method.
(regcache::regcache, regcache::get_thread_arch_aspace_regcache)
(regcache::registers_changed_ptid): Add process_stratum_target
parameter.
(regcache::m_target): New field.
(registers_changed_ptid): Add process_stratum_target parameter.
* remote.c (remote_state::supports_vCont_probed): New field.
(remote_target::async_wait_fd): New method.
(remote_unpush_and_throw): Add remote_target parameter.
(get_current_remote_target): Adjust.
(remote_target::remote_add_inferior): Push target.
(remote_target::remote_add_thread)
(remote_target::remote_notice_new_inferior)
(get_remote_thread_info): Pass target down.
(remote_target::update_thread_list): Skip threads of inferiors
bound to other targets. (remote_target::close): Don't discard
inferiors. (remote_target::add_current_inferior_and_thread)
(remote_target::process_initial_stop_replies)
(remote_target::start_remote)
(remote_target::remote_serial_quit_handler): Pass down target.
(remote_target::remote_unpush_target): New remote_target
parameter. Unpush the target from all inferiors.
(remote_target::remote_unpush_and_throw): New remote_target
parameter. Pass it down.
(remote_target::open_1): Check whether the current inferior has
execution instead of checking whether any inferior is live. Pass
target down.
(remote_target::remote_detach_1): Pass down target. Use
remote_unpush_target.
(extended_remote_target::attach): Pass down target.
(remote_target::remote_vcont_probe): Set supports_vCont_probed.
(remote_target::append_resumption): Pass down target.
(remote_target::append_pending_thread_resumptions)
(remote_target::remote_resume_with_hc, remote_target::resume)
(remote_target::commit_resume): Pass down target.
(remote_target::remote_stop_ns): Check supports_vCont_probed.
(remote_target::interrupt_query)
(remote_target::remove_new_fork_children)
(remote_target::check_pending_events_prevent_wildcard_vcont)
(remote_target::remote_parse_stop_reply)
(remote_target::process_stop_reply): Pass down target.
(first_remote_resumed_thread): New remote_target parameter. Pass
it down.
(remote_target::wait_as): Pass down target.
(unpush_and_perror): New remote_target parameter. Pass it down.
(remote_target::readchar, remote_target::remote_serial_write)
(remote_target::getpkt_or_notif_sane_1)
(remote_target::kill_new_fork_children, remote_target::kill): Pass
down target.
(remote_target::mourn_inferior): Pass down target. Use
remote_unpush_target.
(remote_target::core_of_thread)
(remote_target::remote_btrace_maybe_reopen): Pass down target.
(remote_target::pid_to_exec_file)
(remote_target::thread_handle_to_thread_info): Pass down target.
(remote_target::async_wait_fd): New.
* riscv-fbsd-tdep.c: Include "inferior.h".
(riscv_fbsd_get_thread_local_address): Pass down target.
* sol2-tdep.c (sol2_core_pid_to_str): Pass down target.
* sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs)
(ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback):
Adjust.
* solib-spu.c (spu_skip_standalone_loader): Pass down target.
* solib-svr4.c (enable_break): Pass down target.
* spu-multiarch.c (parse_spufs_run): Pass down target.
* spu-tdep.c (spu2ppu_sniffer): Pass down target.
* target-delegates.c: Regenerate.
* target.c (g_target_stack): Delete.
(current_top_target): Return the current inferior's top target.
(target_has_execution_1): Refer to the passed-in inferior's top
target.
(target_supports_terminal_ours): Check whether the initial
inferior was already created.
(decref_target): New.
(target_stack::push): Incref/decref the target.
(push_target, push_target, unpush_target): Adjust.
(target_stack::unpush): Defref target.
(target_is_pushed): Return bool. Adjust to refer to the current
inferior's target stack.
(dispose_inferior): Delete, and inline parts ...
(target_preopen): ... here. Only dispose of the current inferior.
(target_detach): Hold strong target reference while detaching.
Pass target down.
(target_thread_name): Add assertion.
(target_resume): Pass down target.
(target_ops::beneath, find_target_at): Adjust to refer to the
current inferior's target stack.
(get_dummy_target): New.
(target_pass_ctrlc): Pass the Ctrl-C to the first inferior that
has a thread running.
(initialize_targets): Rename to ...
(_initialize_target): ... this.
* target.h: Include "gdbsupport/refcounted-object.h".
(struct target_ops): Inherit refcounted_object.
(target_ops::shortname, target_ops::longname): Make const.
(target_ops::async_wait_fd): New method.
(decref_target): Declare.
(struct target_ops_ref_policy): New.
(target_ops_ref): New typedef.
(get_dummy_target): Declare function.
(target_is_pushed): Return bool.
* thread-iter.c (all_matching_threads_iterator::m_inf_matches)
(all_matching_threads_iterator::all_matching_threads_iterator):
Handle filter target.
* thread-iter.h (struct all_matching_threads_iterator, struct
all_matching_threads_range, class all_non_exited_threads_range):
Filter by target too. Remove explicit.
* thread.c (threads_executing): Delete.
(inferior_thread): Pass down current inferior.
(clear_thread_inferior_resources): Pass down thread pointer
instead of ptid_t.
(add_thread_silent, add_thread_with_info, add_thread): Add
process_stratum_target parameter. Use it for thread and inferior
searches.
(is_current_thread): New.
(thread_info::deletable): Use it.
(find_thread_ptid, thread_count, in_thread_list)
(thread_change_ptid, set_resumed, set_running): New
process_stratum_target parameter. Pass it down.
(set_executing): New process_stratum_target parameter. Pass it
down. Adjust reference to 'threads_executing'.
(threads_are_executing): New process_stratum_target parameter.
Adjust reference to 'threads_executing'.
(set_stop_requested, finish_thread_state): New
process_stratum_target parameter. Pass it down.
(switch_to_thread): Also match inferior.
(switch_to_thread): New process_stratum_target parameter. Pass it
down.
(update_threads_executing): Reimplement.
* top.c (quit_force): Pop targets from all inferior.
(gdb_init): Don't call initialize_targets.
* windows-nat.c (windows_nat_target) <get_windows_debug_event>:
Declare.
(windows_add_thread, windows_delete_thread): Adjust.
(get_windows_debug_event): Rename to ...
(windows_nat_target::get_windows_debug_event): ... this. Adjust.
* tracefile-tfile.c (tfile_target_open): Pass down target.
* gdbsupport/common-gdbthread.h (struct process_stratum_target):
Forward declare.
(switch_to_thread): Add process_stratum_target parameter.
* mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target
parameter. Use it.
(mi_on_resume): Pass target down.
* nat/fork-inferior.c (startup_inferior): Add
process_stratum_target parameter. Pass it down.
* nat/fork-inferior.h (startup_inferior): Add
process_stratum_target parameter.
* python/py-threadevent.c (py_get_event_thread): Pass target down.
gdb/gdbserver/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* fork-child.c (post_fork_inferior): Pass target down to
startup_inferior.
* inferiors.c (switch_to_thread): Add process_stratum_target
parameter.
* lynx-low.c (lynx_target_ops): Now a process_stratum_target.
* nto-low.c (nto_target_ops): Now a process_stratum_target.
* linux-low.c (linux_target_ops): Now a process_stratum_target.
* remote-utils.c (prepare_resume_reply): Pass the target to
switch_to_thread.
* target.c (the_target): Now a process_stratum_target.
(done_accessing_memory): Pass the target to switch_to_thread.
(set_target_ops): Ajust to use process_stratum_target.
* target.h (struct target_ops): Rename to ...
(struct process_stratum_target): ... this.
(the_target, set_target_ops): Adjust.
(prepare_to_access_memory): Adjust comment.
* win32-low.c (child_xfer_memory): Adjust to use
process_stratum_target.
(win32_target_ops): Now a process_stratum_target.
Another bug exposed by gdb.server/extended-remote-restart.exp in the
multi-target work is that remote_target::start_remote can leave
inferior_ptid and current_inferior() out of sync:
(top-gdb) p current_inferior_->pid
$1 = 29541
(top-gdb) p inferior_ptid
$2 = {m_pid = 29540, m_lwp = 29540, m_tid = 0}
This is caused by writing to inferior_ptid directly instead of using
switch_to_thread. Also, "inferior_list->thread_list->ptid" assumes
that we want the first thread of the first inferior, but that inferior
may not have threads, or with multi-target, that target may be
connected to some other target.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* remote.c (remote_target::start_remote): Don't set inferior_ptid
directly. Instead find the first thread in the thread list and
use switch_to_thread.
The multi-target patch will change the remote target's behavior when:
- the current inferior is connected to an extended-remote target.
- the current inferior is attached to any process.
- some other inferior than than the current one is live.
In current master, we get:
(gdb) tar extended-remote :9999
A program is being debugged already. Kill it? (y or n)
While after multi-target, since each inferior may have its own target
connection, we'll get:
(gdb) tar extended-remote :9999
Already connected to a remote target. Disconnect? (y or n)
That change made gdb.server/extended-remote-restart.exp expose a gdb
bug, because it made "target remote", via gdb_reconnect, just
disconnect from the previous connection, while in current master that
command would kill the inferior before disconnecting. In turn, that
would make a multi-target gdb find processes already running under
control of gdbserver as soon as it reconnects, while in current master
there is never any process around when gdb reconnects, since they'd
all been killed prior to disconnection.
The bug this exposed is that remote_target::remote_add_inferior was
always reusing current_inferior() for the new process, even if the
current inferior was already bound to a process. In the testcase's
case, when we reconnect, the remote is debugging two processes. So
we'd bind the first remote process to the empty current inferior the
first time, and then bind the second remote process to the same
inferior again, essencially losing track of the first process. That
resulted in failed assertions when we look up the inferior for the
first process by PID. The fix is to still prefer binding to the
current inferior (so that plain "target remote" keeps doing what you'd
expect), but not reuse the current inferior if it is already bound to
a process.
This patch tweaks the test to explicitly disconnect before
reconnecting, to avoid GDB killing processes, thus making current GDB
behave the same as it will behave when the multi-target work lands.
That change alone without the GDB fix exposes the bug like so:
(gdb) PASS: gdb.server/extended-remote-restart.exp: kill: 0, follow-child 0: disconnect
target extended-remote localhost:2350
Remote debugging using localhost:2350
src/gdb/thread.c:93: internal-error: thread_info* inferior_thread(): Assertion `tp' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
The original bug that the testcase was written for was related to
killing, (git 9d4a934ce6 ("gdb: Fix assert for extended-remote
target (PR gdb/18050)")), but since the testcase tries reconnecting
with both explicitly killing and not explicitly killing, I think we're
covering the original bug with this testcase change.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* remote.c (remote_target::remote_add_inferior): Don't bind a
process to the current inferior if the current inferior is already
bound to a process.
gdb/testsuite/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* gdb.server/extended-remote-restart.exp (test_reload): Explicitly
disconnect before reconnecting.
The multi-target patch makes inferior_ptid point to null_ptid before
calling into target_wait, which catches bad uses of inferior_ptid,
since the current selected thread in gdb shouldn't have much relation
to the thread that reports an event.
One such bad use is found in remote_target::remote_parse_stop_reply,
where we handle the 'W' or 'X' packets (process exit), and the remote
target does not support the multi-process extensions, i.e., it does
not report the PID of the process that exited.
With the multi-target patch, that would result in a failed assertion,
trying to find the inferior for process pid 0.
gdb/ChangeLog:
2020-01-10 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
Pedro Alves <palves@redhat.com>
* remote.c (remote_target::remote_parse_stop_reply) <W/X packets>:
If no process is specified, return null_ptid instead of
inferior_ptid.
(remote_target::wait_as): Handle TARGET_WAITKIND_EXITED /
TARGET_WAITKIND_SIGNALLED with no pid.
gdb/testsuite/ChangeLog:
2020-01-10 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
Pedro Alves <palves@redhat.com>
* gdb.server/connect-without-multi-process.exp: Also test
continuing to end.
With current master, on a Fedora 27 machine with a kernel with buggy
watchpoint support, I see:
(gdb) PASS: gdb.threads/watchpoint-fork.exp: parent: singlethreaded: hardware breakpoints work
continue
Continuing.
warning: Remote failure reply: E01
Remote communication error. Target disconnected.: Connection reset by peer.
(gdb) FAIL: gdb.threads/watchpoint-fork.exp: parent: singlethreaded: watchpoints work
continue
The program is not being run.
(gdb) FAIL: gdb.threads/watchpoint-fork.exp: parent: singlethreaded: breakpoint after the first fork (the program is no longer running)
The FAILs themselves aren't what's interesting here. What is
interesting is that with the main multi-target patch applied, I was getting this:
(gdb) PASS: gdb.threads/watchpoint-fork.exp: parent: singlethreaded: hardware breakpoints work
continue
Continuing.
warning: Remote failure reply: E01
/home/pedro/brno/pedro/gdb/binutils-gdb-2/build/../src/gdb/inferior.c:285: internal-error: inferior* find_inferior_pid(process_stratum_target*, int): Assertion `pid != 0' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) FAIL: gdb.threads/watchpoint-fork.exp: parent: singlethreaded: watchpoints work (GDB internal error)
The problem is that in remote_target::wait_as, we're hitting this:
switch (buf[0])
{
case 'E': /* Error of some sort. */
/* We're out of sync with the target now. Did it continue or
not? Not is more likely, so report a stop. */
rs->waiting_for_stop_reply = 0;
warning (_("Remote failure reply: %s"), buf);
status->kind = TARGET_WAITKIND_STOPPED;
status->value.sig = GDB_SIGNAL_0;
break;
which leaves event_ptid as null_ptid. At the end of the function, we then reach:
else if (status->kind != TARGET_WAITKIND_EXITED
&& status->kind != TARGET_WAITKIND_SIGNALLED)
{
if (event_ptid != null_ptid)
record_currthread (rs, event_ptid);
else
event_ptid = inferior_ptid; <<<<< here
}
and the trouble is that with the multi-target patch, we'll get here
with inferior_ptid as null_ptid too. That is done exactly to find
these implicit assumptions that inferior_ptid is a good choice for
default thread, which isn't generaly true.
I first thought of fixing this in the "case 'E'" path, but, given that
this "event_ptid = inferior_ptid" path is also taken when the remote
target does not support threads at all, no thread-related packets or
extensions, it's better to fix it in latter path, to handle all
scenarios that miss reporting a thread.
That's what this patch does.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* remote.c (first_remote_resumed_thread): New.
(remote_target::wait_as): Use it as default event_ptid instead of
inferior_ptid.
It's not possible to open a tfile target with an invalid trace_fd, and
it's not possible to close a closed target, so this early return is dead.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* tracefile-tfile.c (tfile_target::close): Assert that trace_fd is
not -1.
- Make get_last_target_status arguments optional. A following patch
will add another argument to get_last_target_status (the event's
target), and passing nullptr when we don't care for some piece of
info is handier than creating dummy local variables.
- Declare nullify_last_target_wait_ptid in a header, and remove the
local extern declaration from linux-fork.c.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* break-catch-sig.c (signal_catchpoint_print_it): Don't pass a
ptid to get_last_target_status.
* break-catch-syscall.c (print_it_catch_syscall): Don't pass a
ptid to get_last_target_status.
* infcmd.c (continue_command): Don't pass a target_waitstatus to
get_last_target_status.
(info_program_command): Don't pass a target_waitstatus to
get_last_target_status.
* infrun.c (init_wait_for_inferior): Use
nullify_last_target_wait_ptid.
(get_last_target_status): Handle nullptr arguments.
(nullify_last_target_wait_ptid): Clear target_last_waitstatus.
(print_stop_event): Don't pass a ptid to get_last_target_status.
(normal_stop): Don't pass a ptid to get_last_target_status.
* infrun.h (get_last_target_status, set_last_target_status): Move
comments here and update.
(nullify_last_target_wait_ptid): Declare.
* linux-fork.c (fork_load_infrun_state): Remove local extern
declaration of nullify_last_target_wait_ptid.
* linux-nat.c (get_detach_signal): Don't pass a target_waitstatus
to get_last_target_status.
Nitika Achra
Simon Marchi
Tom Tromey
Bernd Edlinger
Luis Machado
Andrew Burgess
Ali Tamur
Simon Marchi
Pedro Alves
Tankut Baris Aktemur