option if you run @value{GDBN} from Emacs (@pxref{Emacs, ,
Using @value{GDBN} under @sc{gnu} Emacs}).
-@c @item -xdb
-@c @cindex @code{--xdb}
-@c Run in XDB compatibility mode, allowing the use of certain XDB commands.
-@c For information, see the file @file{xdb_trans.html}, which is usually
-@c installed in the directory @code{/opt/langtools/wdb/doc} on HP-UX
-@c systems.
-
@item -interpreter @var{interp}
@cindex @code{--interpreter}
Use the interpreter @var{interp} for interface with the controlling
Currently, the only platforms with this feature are HP-UX (11.x and later
only?) and @sc{gnu}/Linux (kernel version 2.5.60 and later).
+The fork debugging commands are supported in both native mode and when
+connected to @code{gdbserver} using @kbd{target extended-remote}.
+
By default, when a program forks, @value{GDBN} will continue to debug
the parent process and the child process will run unimpeded.
mode optimizes for single-stepping; it prevents other threads
from preempting the current thread while you are stepping, so that
the focus of debugging does not change unexpectedly.
-Other threads only rarely (or never) get a chance to run
-when you step. They are more likely to run when you @samp{next} over a
-function call, and they are completely free to run when you use commands
+Other threads never get a chance to run when you step, and they are
+completely free to run when you use commands
like @samp{continue}, @samp{until}, or @samp{finish}. However, unless another
thread hits a breakpoint during its timeslice, @value{GDBN} does not change
the current thread away from the thread that you are debugging.
@anchor{linux info os infotypes}
@table @code
+@kindex info os cpus
+@item cpus
+Display the list of all CPUs/cores. For each CPU/core, @value{GDBN} prints
+the available fields from /proc/cpuinfo. For each supported architecture
+different fields are available. Two common entries are processor which gives
+CPU number and bogomips; a system constant that is calculated during
+kernel initialization.
+
+@kindex info os files
+@item files
+Display the list of open file descriptors on the target. For each
+file descriptor, @value{GDBN} prints the identifier of the process
+owning the descriptor, the command of the owning process, the value
+of the descriptor, and the target of the descriptor.
+
+@kindex info os modules
+@item modules
+Display the list of all loaded kernel modules on the target. For each
+module, @value{GDBN} prints the module name, the size of the module in
+bytes, the number of times the module is used, the dependencies of the
+module, the status of the module, and the address of the loaded module
+in memory.
+
+@kindex info os msg
+@item msg
+Display the list of all System V message queues on the target. For each
+message queue, @value{GDBN} prints the message queue key, the message
+queue identifier, the access permissions, the current number of bytes
+on the queue, the current number of messages on the queue, the processes
+that last sent and received a message on the queue, the user and group
+of the owner and creator of the message queue, the times at which a
+message was last sent and received on the queue, and the time at which
+the message queue was last changed.
+
@kindex info os processes
@item processes
Display the list of processes on the target. For each process,
so that processes belonging to the same process group are grouped together
and the process group leader is listed first.
-@kindex info os threads
-@item threads
-Display the list of threads running on the target. For each thread,
-@value{GDBN} prints the identifier of the process that the thread
-belongs to, the command of the process, the thread identifier, and the
-processor core that it is currently running on. The main thread of a
-process is not listed.
-
-@kindex info os files
-@item files
-Display the list of open file descriptors on the target. For each
-file descriptor, @value{GDBN} prints the identifier of the process
-owning the descriptor, the command of the owning process, the value
-of the descriptor, and the target of the descriptor.
-
-@kindex info os sockets
-@item sockets
-Display the list of Internet-domain sockets on the target. For each
-socket, @value{GDBN} prints the address and port of the local and
-remote endpoints, the current state of the connection, the creator of
-the socket, the IP address family of the socket, and the type of the
-connection.
+@kindex info os semaphores
+@item semaphores
+Display the list of all System V semaphore sets on the target. For each
+semaphore set, @value{GDBN} prints the semaphore set key, the semaphore
+set identifier, the access permissions, the number of semaphores in the
+set, the user and group of the owner and creator of the semaphore set,
+and the times at which the semaphore set was operated upon and changed.
@kindex info os shm
@item shm
attaches to the region, and the times at which the region was last
attached to, detach from, and changed.
-@kindex info os semaphores
-@item semaphores
-Display the list of all System V semaphore sets on the target. For each
-semaphore set, @value{GDBN} prints the semaphore set key, the semaphore
-set identifier, the access permissions, the number of semaphores in the
-set, the user and group of the owner and creator of the semaphore set,
-and the times at which the semaphore set was operated upon and changed.
-
-@kindex info os msg
-@item msg
-Display the list of all System V message queues on the target. For each
-message queue, @value{GDBN} prints the message queue key, the message
-queue identifier, the access permissions, the current number of bytes
-on the queue, the current number of messages on the queue, the processes
-that last sent and received a message on the queue, the user and group
-of the owner and creator of the message queue, the times at which a
-message was last sent and received on the queue, and the time at which
-the message queue was last changed.
+@kindex info os sockets
+@item sockets
+Display the list of Internet-domain sockets on the target. For each
+socket, @value{GDBN} prints the address and port of the local and
+remote endpoints, the current state of the connection, the creator of
+the socket, the IP address family of the socket, and the type of the
+connection.
-@kindex info os modules
-@item modules
-Display the list of all loaded kernel modules on the target. For each
-module, @value{GDBN} prints the module name, the size of the module in
-bytes, the number of times the module is used, the dependencies of the
-module, the status of the module, and the address of the loaded module
-in memory.
+@kindex info os threads
+@item threads
+Display the list of threads running on the target. For each thread,
+@value{GDBN} prints the identifier of the process that the thread
+belongs to, the command of the process, the thread identifier, and the
+processor core that it is currently running on. The main thread of a
+process is not listed.
@end table
@item info os
@code{restore} to copy data between target memory and a file. The
@code{dump} and @code{append} commands write data to a file, and the
@code{restore} command reads data from a file back into the inferior's
-memory. Files may be in binary, Motorola S-record, Intel hex, or
-Tektronix Hex format; however, @value{GDBN} can only append to binary
-files.
+memory. Files may be in binary, Motorola S-record, Intel hex,
+Tektronix Hex, or Verilog Hex format; however, @value{GDBN} can only
+append to binary files, and cannot read from Verilog Hex files.
@table @code
Motorola S-record format.
@item tekhex
Tektronix Hex format.
+@item verilog
+Verilog Hex format.
@end table
@value{GDBN} uses the same definitions of these formats as the
Note that this command is implemented only for some systems (as of
this writing, @sc{gnu}/Linux, FreeBSD, Solaris, and S390).
+
+On @sc{gnu}/Linux, this command can take into account the value of the
+file @file{/proc/@var{pid}/coredump_filter} when generating the core
+dump (@pxref{set use-coredump-filter}).
+
+@kindex set use-coredump-filter
+@anchor{set use-coredump-filter}
+@item set use-coredump-filter on
+@itemx set use-coredump-filter off
+Enable or disable the use of the file
+@file{/proc/@var{pid}/coredump_filter} when generating core dump
+files. This file is used by the Linux kernel to decide what types of
+memory mappings will be dumped or ignored when generating a core dump
+file. @var{pid} is the process ID of a currently running process.
+
+To make use of this feature, you have to write in the
+@file{/proc/@var{pid}/coredump_filter} file a value, in hexadecimal,
+which is a bit mask representing the memory mapping types. If a bit
+is set in the bit mask, then the memory mappings of the corresponding
+types will be dumped; otherwise, they will be ignored. This
+configuration is inherited by child processes. For more information
+about the bits that can be set in the
+@file{/proc/@var{pid}/coredump_filter} file, please refer to the
+manpage of @code{core(5)}.
+
+By default, this option is @code{on}. If this option is turned
+@code{off}, @value{GDBN} does not read the @file{coredump_filter} file
+and instead uses the same default value as the Linux kernel in order
+to decide which pages will be dumped in the core dump file. This
+value is currently @code{0x33}, which means that bits @code{0}
+(anonymous private mappings), @code{1} (anonymous shared mappings),
+@code{4} (ELF headers) and @code{5} (private huge pages) are active.
+This will cause these memory mappings to be dumped automatically.
@end table
@node Character Sets
@end smallexample
@end table
+@table @code
+@item compile print @var{expr}
+@itemx compile print /@var{f} @var{expr}
+Compile and execute @var{expr} with the compiler language found as the
+current language in @value{GDBN} (@pxref{Languages}). By default the
+value of @var{expr} is printed in a format appropriate to its data type;
+you can choose a different format by specifying @samp{/@var{f}}, where
+@var{f} is a letter specifying the format; see @ref{Output Formats,,Output
+Formats}.
+
+@item compile print
+@itemx compile print /@var{f}
+@cindex reprint the last value
+Alternatively you can enter the expression (source code producing it) as
+multiple lines of text. To enter this mode, invoke the @samp{compile print}
+command without any text following the command. This will start the
+multiple-line editor.
+@end table
+
+@noindent
+The process of compiling and injecting the code can be inspected using:
+
+@table @code
+@anchor{set debug compile}
+@item set debug compile
+@cindex compile command debugging info
+Turns on or off display of @value{GDBN} process of compiling and
+injecting the code. The default is off.
+
+@item show debug compile
+Displays the current state of displaying @value{GDBN} process of
+compiling and injecting the code.
+@end table
+
+@subsection Compilation options for the @code{compile} command
+
+@value{GDBN} needs to specify the right compilation options for the code
+to be injected, in part to make its ABI compatible with the inferior
+and in part to make the injected code compatible with @value{GDBN}'s
+injecting process.
+
+@noindent
+The options used, in increasing precedence:
+
+@table @asis
+@item target architecture and OS options (@code{gdbarch})
+These options depend on target processor type and target operating
+system, usually they specify at least 32-bit (@code{-m32}) or 64-bit
+(@code{-m64}) compilation option.
+
+@item compilation options recorded in the target
+@value{NGCC} (since version 4.7) stores the options used for compilation
+into @code{DW_AT_producer} part of DWARF debugging information according
+to the @value{NGCC} option @code{-grecord-gcc-switches}. One has to
+explicitly specify @code{-g} during inferior compilation otherwise
+@value{NGCC} produces no DWARF. This feature is only relevant for
+platforms where @code{-g} produces DWARF by default, otherwise one may
+try to enforce DWARF by using @code{-gdwarf-4}.
+
+@item compilation options set by @code{set compile-args}
+@end table
+
+@noindent
+You can override compilation options using the following command:
+
+@table @code
+@item set compile-args
+@cindex compile command options override
+Set compilation options used for compiling and injecting code with the
+@code{compile} commands. These options override any conflicting ones
+from the target architecture and/or options stored during inferior
+compilation.
+
+@item show compile-args
+Displays the current state of compilation options override.
+This does not show all the options actually used during compilation,
+use @ref{set debug compile} for that.
+@end table
+
@subsection Caveats when using the @code{compile} command
There are a few caveats to keep in mind when using the @code{compile}
will print to the console.
@end table
+@subsection Compiler search for the @code{compile} command
+
+@value{GDBN} needs to find @value{NGCC} for the inferior being debugged which
+may not be obvious for remote targets of different architecture than where
+@value{GDBN} is running. Environment variable @code{PATH} (@code{PATH} from
+shell that executed @value{GDBN}, not the one set by @value{GDBN}
+command @code{set environment}). @xref{Environment}. @code{PATH} on
+@value{GDBN} host is searched for @value{NGCC} binary matching the
+target architecture and operating system.
+
+Specifically @code{PATH} is searched for binaries matching regular expression
+@code{@var{arch}(-[^-]*)?-@var{os}-gcc} according to the inferior target being
+debugged. @var{arch} is processor name --- multiarch is supported, so for
+example both @code{i386} and @code{x86_64} targets look for pattern
+@code{(x86_64|i.86)} and both @code{s390} and @code{s390x} targets look
+for pattern @code{s390x?}. @var{os} is currently supported only for
+pattern @code{linux(-gnu)?}.
+
@node GDB Files
@chapter @value{GDBN} Files
that match @var{regex}. If @var{regex} is omitted then print
all shared libraries that are loaded.
+@kindex info dll
+@item info dll @var{regex}
+This is an alias of @code{info sharedlibrary}.
+
@kindex sharedlibrary
@kindex share
@item sharedlibrary @var{regex}
to specify the search directories for target libraries.
@table @code
-@cindex prefix for shared library file names
+@cindex prefix for executable and shared library file names
@cindex system root, alternate
@kindex set solib-absolute-prefix
@kindex set sysroot
Use @var{path} as the system root for the program being debugged. Any
absolute shared library paths will be prefixed with @var{path}; many
runtime loaders store the absolute paths to the shared library in the
-target program's memory. If you use @code{set sysroot} to find shared
-libraries, they need to be laid out in the same way that they are on
-the target, with e.g.@: a @file{/lib} and @file{/usr/lib} hierarchy
-under @var{path}.
-
-If @var{path} starts with the sequence @file{remote:}, @value{GDBN} will
-retrieve the target libraries from the remote system. This is only
-supported when using a remote target that supports the @code{remote get}
-command (@pxref{File Transfer,,Sending files to a remote system}).
-The part of @var{path} following the initial @file{remote:}
-(if present) is used as system root prefix on the remote file system.
-@footnote{If you want to specify a local system root using a directory
-that happens to be named @file{remote:}, you need to use some equivalent
-variant of the name like @file{./remote:}.}
+target program's memory. When starting processes remotely, and when
+attaching to already-running processes (local or remote), their
+executable filenames will be prefixed with @var{path} if reported to
+@value{GDBN} as absolute by the operating system. If you use
+@code{set sysroot} to find executables and shared libraries, they need
+to be laid out in the same way that they are on the target, with
+e.g.@: a @file{/bin}, @file{/lib} and @file{/usr/lib} hierarchy under
+@var{path}.
+
+If @var{path} starts with the sequence @file{target:} and the target
+system is remote then @value{GDBN} will retrieve the target binaries
+from the remote system. This is only supported when using a remote
+target that supports the @code{remote get} command (@pxref{File
+Transfer,,Sending files to a remote system}). The part of @var{path}
+following the initial @file{target:} (if present) is used as system
+root prefix on the remote file system. If @var{path} starts with the
+sequence @file{remote:} this is converted to the sequence
+@file{target:} by @code{set sysroot}@footnote{Historically the
+functionality to retrieve binaries from the remote system was
+provided by prefixing @var{path} with @file{remote:}}. If you want
+to specify a local system root using a directory that happens to be
+named @file{target:} or @file{remote:}, you need to use some
+equivalent variant of the name like @file{./target:}.
For targets with an MS-DOS based filesystem, such as MS-Windows and
SymbianOS, @value{GDBN} tries prefixing a few variants of the target
c:/foo/bar.dll @result{} /path/to/sysroot/c:/foo/bar.dll
@end smallexample
-If that does not find the shared library, @value{GDBN} tries removing
+If that does not find the binary, @value{GDBN} tries removing
the @samp{:} character from the drive spec, both for convenience, and,
for the case of the host file system not supporting file names with
colons:
@value{GDBN} can find the correct copies of both
@file{c:\sys\bin\foo.dll}, and @file{z:\sys\bin\bar.dll}.
-If that still does not find the shared library, @value{GDBN} tries
+If that still does not find the binary, @value{GDBN} tries
removing the whole drive spec from the target file name:
@smallexample
@kindex show sysroot
@item show sysroot
-Display the current shared library prefix.
+Display the current executable and shared library prefix.
@kindex set solib-search-path
@item set solib-search-path @var{path}
@node Connecting
@section Connecting to a Remote Target
-On the @value{GDBN} host machine, you will need an unstripped copy of
-your program, since @value{GDBN} needs symbol and debugging information.
-Start up @value{GDBN} as usual, using the name of the local copy of your
-program as the first argument.
+@value{GDBN} needs an unstripped copy of your program to access symbol
+and debugging information. Some remote targets (@pxref{qXfer
+executable filename read}, and @pxref{Host I/O Packets}) allow
+@value{GDBN} to access program files over the same connection used to
+communicate with @value{GDBN}. With such a target, if the remote
+program is unstripped, the only command you need is @code{target
+remote}. Otherwise, start up @value{GDBN} using the name of the local
+unstripped copy of your program as the first argument, or use the
+@code{file} command.
@cindex @code{target remote}
@value{GDBN} can communicate with the target over a serial line, or
@item show serial baud
Show the current speed of the remote connection.
+@item set serial parity @var{parity}
+Set the parity for the remote serial I/O. Supported values of @var{parity} are:
+@code{even}, @code{none}, and @code{odd}. The default is @code{none}.
+
+@item show serial parity
+Show the current parity of the serial port.
+
@item set remotebreak
@cindex interrupt remote programs
@cindex BREAK signal instead of Ctrl-C
@tab @code{Z4}
@tab @code{awatch}
+@item @code{pid-to-exec-file}
+@tab @code{qXfer:exec-file:read}
+@tab @code{attach}, @code{run}
+
@item @code{target-features}
@tab @code{qXfer:features:read}
@tab @code{set architecture}
@tab @code{vFile:readlink}
@tab Host I/O
+@item @code{hostio-fstat-packet}
+@tab @code{vFile:fstat}
+@tab Host I/O
+
@item @code{noack-packet}
@tab @code{QStartNoAckMode}
@tab Packet acknowledgment
@item @code{conditional-breakpoints-packet}
@tab @code{Z0 and Z1}
@tab @code{Support for target-side breakpoint condition evaluation}
+
+@item @code{swbreak-feature}
+@tab @code{swbreak stop reason}
+@tab @code{break}
+
+@item @code{hwbreak-feature}
+@tab @code{hwbreak stop reason}
+@tab @code{hbreak}
+
+@item @code{fork-event-feature}
+@tab @code{fork stop reason}
+@tab @code{fork}
+
+@item @code{vfork-event-feature}
+@tab @code{vfork stop reason}
+@tab @code{vfork}
+
@end multitable
@node Remote Stub
Thread Information Block (readable on the X86 CPU family using @code{$fs}
selector for 32-bit programs and @code{$gs} for 64-bit programs).
-@kindex info dll
-@item info dll
-This is a Cygwin-specific alias of @code{info shared}.
-
@kindex set cygwin-exceptions
@cindex debugging the Cygwin DLL
@cindex Cygwin DLL, debugging
@item show debug coff-pe-read
Displays the current state of displaying debugging messages related to
reading of COFF/PE exported symbols.
-@item set debug dwarf2-die
-@cindex DWARF2 DIEs
-Dump DWARF2 DIEs after they are read in.
+@item set debug dwarf-die
+@cindex DWARF DIEs
+Dump DWARF DIEs after they are read in.
The value is the number of nesting levels to print.
A value of zero turns off the display.
-@item show debug dwarf2-die
-Show the current state of DWARF2 DIE debugging.
-@item set debug dwarf2-read
-@cindex DWARF2 Reading
+@item show debug dwarf-die
+Show the current state of DWARF DIE debugging.
+@item set debug dwarf-read
+@cindex DWARF Reading
Turns on or off display of debugging messages related to reading
DWARF debug info. The default is 0 (off).
A value of 1 provides basic information.
A value greater than 1 provides more verbose information.
-@item show debug dwarf2-read
-Show the current state of DWARF2 reader debugging.
+@item show debug dwarf-read
+Show the current state of DWARF reader debugging.
@item set debug displaced
@cindex displaced stepping debugging info
Turns on or off display of @value{GDBN} debugging info for the
The TUI mode is enabled by default when you invoke @value{GDBN} as
@samp{@value{GDBP} -tui}.
You can also switch in and out of TUI mode while @value{GDBN} runs by
-using various TUI commands and key bindings, such as @kbd{C-x C-a}.
-@xref{TUI Keys, ,TUI Key Bindings}.
+using various TUI commands and key bindings, such as @command{tui
+enable} or @kbd{C-x C-a}. @xref{TUI Commands, ,TUI Commands} and
+@ref{TUI Keys, ,TUI Key Bindings}.
@node TUI Overview
@section TUI Overview
possible or desirable to enable curses window management.
@table @code
+@item tui enable
+@kindex tui enable
+Activate TUI mode. The last active TUI window layout will be used if
+TUI mode has prevsiouly been used in the current debugging session,
+otherwise a default layout is used.
+
+@item tui disable
+@kindex tui disable
+Disable TUI mode, returning to the console interpreter.
+
@item info win
@kindex info win
List and give the size of all displayed windows.
following: @code{general}, @code{float}, @code{system}, @code{vector},
@code{all}, @code{save}, @code{restore}.
+@item tui reg prev
+Show the previous register group. The list of register groups as well
+as their order is target specific. The predefined register groups are
+the following: @code{general}, @code{float}, @code{system},
+@code{vector}, @code{all}, @code{save}, @code{restore}.
+
@item tui reg system
Show the system registers in the register window.
@item syscall-entry
The inferior entered a system call. This is reported when @code{catch
syscall} (@pxref{Set Catchpoints}) has been used.
-@item syscall-entry
+@item syscall-return
The inferior returned from a system call. This is reported when
@code{catch syscall} (@pxref{Set Catchpoints}) has been used.
@item exec
@table @samp
@item @var{address}
An expression specifying the address of the first memory word to be
-read. Complex expressions containing embedded white space should be
+written. Complex expressions containing embedded white space should be
quoted using the C convention.
@item @var{contents}
@smallexample
@value{GDBP}
-info-os
-^done,OSDataTable=@{nr_rows="9",nr_cols="3",
+^done,OSDataTable=@{nr_rows="10",nr_cols="3",
hdr=[@{width="10",alignment="-1",col_name="col0",colhdr="Type"@},
@{width="10",alignment="-1",col_name="col1",colhdr="Description"@},
@{width="10",alignment="-1",col_name="col2",colhdr="Title"@}],
-body=[item=@{col0="processes",col1="Listing of all processes",
+body=[item=@{col0="cpus",col1="Listing of all cpus/cores on the system",
+ col2="CPUs"@},
+ item=@{col0="files",col1="Listing of all file descriptors",
+ col2="File descriptors"@},
+ item=@{col0="modules",col1="Listing of all loaded kernel modules",
+ col2="Kernel modules"@},
+ item=@{col0="msg",col1="Listing of all message queues",
+ col2="Message queues"@},
+ item=@{col0="processes",col1="Listing of all processes",
col2="Processes"@},
item=@{col0="procgroups",col1="Listing of all process groups",
col2="Process groups"@},
- item=@{col0="threads",col1="Listing of all threads",
- col2="Threads"@},
- item=@{col0="files",col1="Listing of all file descriptors",
- col2="File descriptors"@},
- item=@{col0="sockets",col1="Listing of all internet-domain sockets",
- col2="Sockets"@},
- item=@{col0="shm",col1="Listing of all shared-memory regions",
- col2="Shared-memory regions"@},
item=@{col0="semaphores",col1="Listing of all semaphores",
col2="Semaphores"@},
- item=@{col0="msg",col1="Listing of all message queues",
- col2="Message queues"@},
- item=@{col0="modules",col1="Listing of all loaded kernel modules",
- col2="Kernel modules"@}]@}
+ item=@{col0="shm",col1="Listing of all shared-memory regions",
+ col2="Shared-memory regions"@},
+ item=@{col0="sockets",col1="Listing of all internet-domain sockets",
+ col2="Sockets"@},
+ item=@{col0="threads",col1="Listing of all threads",
+ col2="Threads"@}]
@value{GDBP}
-info-os processes
^done,OSDataTable=@{nr_rows="190",nr_cols="4",
a recursive definition of the data type as stored in @value{GDBN}'s
data structures, including its flags and contained types.
-@kindex maint set dwarf2 always-disassemble
-@kindex maint show dwarf2 always-disassemble
-@item maint set dwarf2 always-disassemble
-@item maint show dwarf2 always-disassemble
+@kindex maint set dwarf always-disassemble
+@kindex maint show dwarf always-disassemble
+@item maint set dwarf always-disassemble
+@item maint show dwarf always-disassemble
Control the behavior of @code{info address} when using DWARF debugging
information.
For more information on these expressions, see
@uref{http://www.dwarfstd.org/, the DWARF standard}.
-@kindex maint set dwarf2 max-cache-age
-@kindex maint show dwarf2 max-cache-age
-@item maint set dwarf2 max-cache-age
-@itemx maint show dwarf2 max-cache-age
-Control the DWARF 2 compilation unit cache.
+@kindex maint set dwarf max-cache-age
+@kindex maint show dwarf max-cache-age
+@item maint set dwarf max-cache-age
+@itemx maint show dwarf max-cache-age
+Control the DWARF compilation unit cache.
-@cindex DWARF 2 compilation units cache
+@cindex DWARF compilation units cache
In object files with inter-compilation-unit references, such as those
-produced by the GCC option @samp{-feliminate-dwarf2-dups}, the DWARF 2
+produced by the GCC option @samp{-feliminate-dwarf2-dups}, the DWARF
reader needs to frequently refer to previously read compilation units.
This setting controls how long a compilation unit will remain in the
cache if it is not referenced. A higher limit means that cached
conditions that should be taken into consideration when deciding if
the breakpoint trigger should be reported back to @var{GDBN}.
+See also the @samp{swbreak} stop reason (@pxref{swbreak stop reason})
+for how to best report a memory breakpoint event to @value{GDBN}.
+
The @var{cond_list} parameter is comprised of a series of expressions,
concatenated without separators. Each expression has the following form:
beginning when executing backward) of the log. The value of @var{r}
will be either @samp{begin} or @samp{end}. @xref{Reverse Execution},
for more information.
+
+@item swbreak
+@anchor{swbreak stop reason}
+The packet indicates a memory breakpoint instruction was executed,
+irrespective of whether it was @value{GDBN} that planted the
+breakpoint or the breakpoint is hardcoded in the program. The @var{r}
+part must be left empty.
+
+On some architectures, such as x86, at the architecture level, when a
+breakpoint instruction executes the program counter points at the
+breakpoint address plus an offset. On such targets, the stub is
+responsible for adjusting the PC to point back at the breakpoint
+address.
+
+This packet should not be sent by default; older @value{GDBN} versions
+did not support it. @value{GDBN} requests it, by supplying an
+appropriate @samp{qSupported} feature (@pxref{qSupported}). The
+remote stub must also supply the appropriate @samp{qSupported} feature
+indicating support.
+
+This packet is required for correct non-stop mode operation.
+
+@item hwbreak
+The packet indicates the target stopped for a hardware breakpoint.
+The @var{r} part must be left empty.
+
+The same remarks about @samp{qSupported} and non-stop mode above
+apply.
+
+@cindex fork events, remote reply
+@item fork
+The packet indicates that @code{fork} was called, and @var{r}
+is the thread ID of the new child process. Refer to
+@ref{thread-id syntax} for the format of the @var{thread-id}
+field. This packet is only applicable to targets that support
+fork events.
+
+This packet should not be sent by default; older @value{GDBN} versions
+did not support it. @value{GDBN} requests it, by supplying an
+appropriate @samp{qSupported} feature (@pxref{qSupported}). The
+remote stub must also supply the appropriate @samp{qSupported} feature
+indicating support.
+
+@cindex vfork events, remote reply
+@item vfork
+The packet indicates that @code{vfork} was called, and @var{r}
+is the thread ID of the new child process. Refer to
+@ref{thread-id syntax} for the format of the @var{thread-id}
+field. This packet is only applicable to targets that support
+vfork events.
+
+This packet should not be sent by default; older @value{GDBN} versions
+did not support it. @value{GDBN} requests it, by supplying an
+appropriate @samp{qSupported} feature (@pxref{qSupported}). The
+remote stub must also supply the appropriate @samp{qSupported} feature
+indicating support.
+
+@cindex vforkdone events, remote reply
+@item vforkdone
+The packet indicates that a child process created by a vfork
+has either called @code{exec} or terminated, so that the
+address spaces of the parent and child process are no longer
+shared. The @var{r} part is ignored. This packet is only
+applicable to targets that support vforkdone events.
+
+This packet should not be sent by default; older @value{GDBN} versions
+did not support it. @value{GDBN} requests it, by supplying an
+appropriate @samp{qSupported} feature (@pxref{qSupported}). The
+remote stub must also supply the appropriate @samp{qSupported} feature
+indicating support.
+
@end table
@item W @var{AA}
This feature indicates whether @value{GDBN} supports the
@samp{qRelocInsn} packet (@pxref{Tracepoint Packets,,Relocate
instruction reply packet}).
+
+@item swbreak
+This feature indicates whether @value{GDBN} supports the swbreak stop
+reason in stop replies. @xref{swbreak stop reason}, for details.
+
+@item hwbreak
+This feature indicates whether @value{GDBN} supports the hwbreak stop
+reason in stop replies. @xref{swbreak stop reason}, for details.
+
+@item fork-events
+This feature indicates whether @value{GDBN} supports fork event
+extensions to the remote protocol. @value{GDBN} does not use such
+extensions unless the stub also reports that it supports them by
+including @samp{fork-events+} in its @samp{qSupported} reply.
+
+@item vfork-events
+This feature indicates whether @value{GDBN} supports vfork event
+extensions to the remote protocol. @value{GDBN} does not use such
+extensions unless the stub also reports that it supports them by
+including @samp{vfork-events+} in its @samp{qSupported} reply.
@end table
Stubs should ignore any unknown values for
@tab @samp{-}
@tab Yes
+@item @samp{qXfer:exec-file:read}
+@tab No
+@tab @samp{-}
+@tab Yes
+
@item @samp{qXfer:features:read}
@tab No
@tab @samp{-}
@tab @samp{-}
@tab No
+@item @samp{swbreak}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{hwbreak}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{fork-events}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{vfork-events}
+@tab No
+@tab @samp{-}
+@tab No
+
@end multitable
These are the currently defined stub features, in more detail:
The remote stub understands the @samp{qXfer:btrace-conf:read}
packet (@pxref{qXfer btrace-conf read}).
+@item qXfer:exec-file:read
+The remote stub understands the @samp{qXfer:exec-file:read} packet
+(@pxref{qXfer executable filename read}).
+
@item qXfer:features:read
The remote stub understands the @samp{qXfer:features:read} packet
(@pxref{qXfer target description read}).
@item Qbtrace-conf:bts:size
The remote stub understands the @samp{Qbtrace-conf:bts:size} packet.
+@item swbreak
+The remote stub reports the @samp{swbreak} stop reason for memory
+breakpoints.
+
+@item hwbreak
+The remote stub reports the @samp{hwbreak} stop reason for hardware
+breakpoints.
+
+@item fork-events
+The remote stub reports the @samp{fork} stop reason for fork events.
+
+@item vfork-events
+The remote stub reports the @samp{vfork} stop reason for vfork events
+and vforkdone events.
+
@end table
@item qSymbol::
This packet is not probed by default; the remote stub must request it
by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
+@item qXfer:exec-file:read:@var{annex}:@var{offset},@var{length}
+@anchor{qXfer executable filename read}
+Return the full absolute name of the file that was executed to create
+a process running on the remote system. The annex specifies the
+numeric process ID of the process to query, encoded as a hexadecimal
+number. If the annex part is empty the remote stub should return the
+filename corresponding to the currently executing process.
+
+This packet is not probed by default; the remote stub must request it,
+by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
+
@item qXfer:features:read:@var{annex}:@var{offset},@var{length}
@anchor{qXfer target description read}
Access the @dfn{target description}. @xref{Target Descriptions}. The
which may be shorter than the length of @var{data}, or -1 if an
error occurred.
+@item vFile:fstat: @var{fd}
+Get information about the open file corresponding to @var{fd}.
+On success the information is returned as a binary attachment
+and the return value is the size of this attachment in bytes.
+If an error occurs the return value is -1. The format of the
+returned binary attachment is as described in @ref{struct stat}.
+
@item vFile:unlink: @var{filename}
Delete the file at @var{filename} on the target. Return 0,
or -1 if an error occurs. The @var{filename} is a string.
or if the target is not attached to any process, it shall respond
@samp{OK}.
+If the stub supports non-stop mode, it should also support the
+@samp{swbreak} stop reason if software breakpoints are supported, and
+the @samp{hwbreak} stop reason if hardware breakpoints are supported
+(@pxref{swbreak stop reason}). This is because given the asynchronous
+nature of non-stop mode, between the time a thread hits a breakpoint
+and the time the event is finally processed by @value{GDBN}, the
+breakpoint may have already been removed from the target. Due to
+this, @value{GDBN} needs to be able to tell whether a trap stop was
+caused by a delayed breakpoint event, which should be ignored, as
+opposed to a random trap signal, which should be reported to the user.
+Note the @samp{swbreak} feature implies that the target is responsible
+for adjusting the PC when a software breakpoint triggers, if
+necessary, such as on the x86 architecture.
+
@node Packet Acknowledgment
@section Packet Acknowledgment
projects / deliverable / binutils-gdb.git / blobdiff