@cindex skipping over functions and files
The program you are debugging may contain some functions which are
-uninteresting to debug. The @code{skip} comand lets you tell @value{GDBN} to
-skip a function or all functions in a file when stepping.
+uninteresting to debug. The @code{skip} command lets you tell @value{GDBN} to
+skip a function, all functions in a file or a particular function in
+a particular file when stepping.
For example, consider the following C function:
@code{step} at line 103, you'll step over @code{boring} and directly into
@code{foo}.
-You can also instruct @value{GDBN} to skip all functions in a file, with, for
-example, @code{skip file boring.c}.
+Functions may be skipped by providing either a function name, linespec
+(@pxref{Specify Location}), regular expression that matches the function's
+name, file name or a @code{glob}-style pattern that matches the file name.
+
+On Posix systems the form of the regular expression is
+``Extended Regular Expressions''. See for example @samp{man 7 regex}
+on @sc{gnu}/Linux systems. On non-Posix systems the form of the regular
+expression is whatever is provided by the @code{regcomp} function of
+the underlying system.
+See for example @samp{man 7 glob} on @sc{gnu}/Linux systems for a
+description of @code{glob}-style patterns.
+
+@table @code
+@kindex skip
+@item skip @r{[}@var{options}@r{]}
+The basic form of the @code{skip} command takes zero or more options
+that specify what to skip.
+The @var{options} argument is any useful combination of the following:
@table @code
+@item -file @var{file}
+@itemx -fi @var{file}
+Functions in @var{file} will be skipped over when stepping.
+
+@item -gfile @var{file-glob-pattern}
+@itemx -gfi @var{file-glob-pattern}
+@cindex skipping over files via glob-style patterns
+Functions in files matching @var{file-glob-pattern} will be skipped
+over when stepping.
+
+@smallexample
+(gdb) skip -gfi utils/*.c
+@end smallexample
+
+@item -function @var{linespec}
+@itemx -fu @var{linespec}
+Functions named by @var{linespec} or the function containing the line
+named by @var{linespec} will be skipped over when stepping.
+@xref{Specify Location}.
+
+@item -rfunction @var{regexp}
+@itemx -rfu @var{regexp}
+@cindex skipping over functions via regular expressions
+Functions whose name matches @var{regexp} will be skipped over when stepping.
+
+This form is useful for complex function names.
+For example, there is generally no need to step into C@t{++} @code{std::string}
+constructors or destructors. Plus with C@t{++} templates it can be hard to
+write out the full name of the function, and often it doesn't matter what
+the template arguments are. Specifying the function to be skipped as a
+regular expression makes this easier.
+
+@smallexample
+(gdb) skip -rfu ^std::(allocator|basic_string)<.*>::~?\1 *\(
+@end smallexample
+
+If you want to skip every templated C@t{++} constructor and destructor
+in the @code{std} namespace you can do:
+
+@smallexample
+(gdb) skip -rfu ^std::([a-zA-z0-9_]+)<.*>::~?\1 *\(
+@end smallexample
+@end table
+
+If no options are specified, the function you're currently debugging
+will be skipped.
+
@kindex skip function
-@item skip @r{[}@var{linespec}@r{]}
-@itemx skip function @r{[}@var{linespec}@r{]}
+@item skip function @r{[}@var{linespec}@r{]}
After running this command, the function named by @var{linespec} or the
function containing the line named by @var{linespec} will be skipped over when
stepping. @xref{Specify Location}.
After running this command, any function whose source lives in @var{filename}
will be skipped over when stepping.
+@smallexample
+(gdb) skip file boring.c
+File boring.c will be skipped when stepping.
+@end smallexample
+
If you do not specify @var{filename}, functions whose source lives in the file
you're currently debugging will be skipped.
@end table
@table @emph
@item Identifier
A number identifying this skip.
-@item Type
-The type of this skip, either @samp{function} or @samp{file}.
@item Enabled or Disabled
-Enabled skips are marked with @samp{y}. Disabled skips are marked with @samp{n}.
-@item Address
-For function skips, this column indicates the address in memory of the function
-being skipped. If you've set a function skip on a function which has not yet
-been loaded, this field will contain @samp{<PENDING>}. Once a shared library
-which has the function is loaded, @code{info skip} will show the function's
-address here.
-@item What
-For file skips, this field contains the filename being skipped. For functions
-skips, this field contains the function name and its line number in the file
-where it is defined.
+Enabled skips are marked with @samp{y}.
+Disabled skips are marked with @samp{n}.
+@item Glob
+If the file name is a @samp{glob} pattern this is @samp{y}.
+Otherwise it is @samp{n}.
+@item File
+The name or @samp{glob} pattern of the file to be skipped.
+If no file is specified this is @samp{<none>}.
+@item RE
+If the function name is a @samp{regular expression} this is @samp{y}.
+Otherwise it is @samp{n}.
+@item Function
+The name or regular expression of the function to skip.
+If no function is specified this is @samp{<none>}.
@end table
@kindex skip delete
Depending on target support, @code{$_siginfo} may also be writable.
+@cindex Intel MPX boundary violations
+@cindex boundary violations, Intel MPX
+On some targets, a @code{SIGSEGV} can be caused by a boundary
+violation, i.e., accessing an address outside of the allowed range.
+In those cases @value{GDBN} may displays additional information,
+depending on how @value{GDBN} has been told to handle the signal.
+With @code{handle stop SIGSEGV}, @value{GDBN} displays the violation
+kind: "Upper" or "Lower", the memory address accessed and the
+bounds, while with @code{handle nostop SIGSEGV} no additional
+information is displayed.
+
+The usual output of a segfault is:
+@smallexample
+Program received signal SIGSEGV, Segmentation fault
+0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
+68 value = *(p + len);
+@end smallexample
+
+While a bound violation is presented as:
+@smallexample
+Program received signal SIGSEGV, Segmentation fault
+Upper bound violation while accessing address 0x7fffffffc3b3
+Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
+0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
+68 value = *(p + len);
+@end smallexample
+
@node Thread Stops
@section Stopping and Starting Multi-thread Programs
character set than GDB does
* Caching Target Data:: Data caching for targets
* Searching Memory:: Searching memory for a sequence of bytes
+* Value Sizes:: Managing memory allocated for values
@end menu
@node Expressions
@table @r
@item @var{n}, the repeat count
The repeat count is a decimal integer; the default is 1. It specifies
-how much memory (counting by units @var{u}) to display.
+how much memory (counting by units @var{u}) to display. If a negative
+number is specified, memory is examined backward from @var{addr}.
@c This really is **decimal**; unaffected by 'set radix' as of GDB
@c 4.1.2.
words (@samp{w}) of memory above the stack pointer (here, @samp{$sp};
@pxref{Registers, ,Registers}) in hexadecimal (@samp{x}).
+You can also specify a negative repeat count to examine memory backward
+from the given address. For example, @samp{x/-3uh 0x54320} prints three
+halfwords (@code{h}) at @code{0x54314}, @code{0x54328}, and @code{0x5431c}.
+
Since the letters indicating unit sizes are all distinct from the
letters specifying output formats, you do not have to remember whether
unit size or format comes first; either order works. The output
@code{disassemble} gives an alternative way of inspecting machine
instructions; see @ref{Machine Code,,Source and Machine Code}.
+If a negative repeat count is specified for the formats @samp{s} or @samp{i},
+the command displays null-terminated strings or instructions before the given
+address as many as the absolute value of the given number. For the @samp{i}
+format, we use line number information in the debug info to accurately locate
+instruction boundaries while disassembling backward. If line info is not
+available, the command stops examining memory with an error message.
+
All the defaults for the arguments to @code{x} are designed to make it
easy to continue scanning memory with minimal specifications each time
you use @code{x}. For example, after you have inspected three machine
by @var{number_of_frames}, whereas @code{$_caller_matches} only checks the
frame specified by @var{number_of_frames}.
+@item $_as_string(@var{value})
+@findex $_as_string@r{, convenience function}
+Return the string representation of @var{value}.
+
+This function is useful to obtain the textual label (enumerator) of an
+enumeration value. For example, assuming the variable @var{node} is of
+an enumerated type:
+
+@smallexample
+(gdb) printf "Visiting node of type %s\n", $_as_string(node)
+Visiting node of type NODE_INTEGER
+@end smallexample
+
@end table
@value{GDBN} provides the ability to list and get help on
$2 = (void *) 0x8049560
@end smallexample
+@node Value Sizes
+@section Value Sizes
+
+Whenever @value{GDBN} prints a value memory will be allocated within
+@value{GDBN} to hold the contents of the value. It is possible in
+some languages with dynamic typing systems, that an invalid program
+may indicate a value that is incorrectly large, this in turn may cause
+@value{GDBN} to try and allocate an overly large ammount of memory.
+
+@table @code
+@kindex set max-value-size
+@item set max-value-size @var{bytes}
+@itemx set max-value-size unlimited
+Set the maximum size of memory that @value{GDBN} will allocate for the
+contents of a value to @var{bytes}, trying to display a value that
+requires more memory than that will result in an error.
+
+Setting this variable does not effect values that have already been
+allocated within @value{GDBN}, only future allocations.
+
+There's a minimum size that @code{max-value-size} can be set to in
+order that @value{GDBN} can still operate correctly, this minimum is
+currently 16 bytes.
+
+The limit applies to the results of some subexpressions as well as to
+complete expressions. For example, an expression denoting a simple
+integer component, such as @code{x.y.z}, may fail if the size of
+@var{x.y} is dynamic and exceeds @var{bytes}. On the other hand,
+@value{GDBN} is sometimes clever; the expression @code{A[i]}, where
+@var{A} is an array variable with non-constant size, will generally
+succeed regardless of the bounds on @var{A}, as long as the component
+size is less than @var{bytes}.
+
+The default value of @code{max-value-size} is currently 64k.
+
+@kindex show max-value-size
+@item show max-value-size
+Show the maximum size of memory, in bytes, that @value{GDBN} will
+allocate for the contents of a value.
+@end table
+
@node Optimized Code
@chapter Debugging Optimized Code
@cindex optimized code, debugging
Collect the return address. This is helpful if you want to see more
of a backtrace.
+@emph{Note:} The return address location can not always be reliably
+determined up front, and the wrong address / registers may end up
+collected instead. On some architectures the reliability is higher
+for tracepoints at function entry, while on others it's the opposite.
+When this happens, backtracing will stop because the return address is
+found unavailable (unless another collect rule happened to match it).
+
@item $_probe_argc
Collects the number of arguments from the static probe at which the
tracepoint is located.
Same as @samp{tfind none}.
@item tfind
-No argument means find the next trace snapshot.
+No argument means find the next trace snapshot or find the first
+one if no trace snapshot is selected.
@item tfind -
Find the previous trace snapshot before the current one. This permits
@section Supported Languages
@value{GDBN} supports C, C@t{++}, D, Go, Objective-C, Fortran, Java,
-OpenCL C, Pascal, assembly, Modula-2, and Ada.
+OpenCL C, Pascal, Rust, assembly, Modula-2, and Ada.
@c This is false ...
Some @value{GDBN} features may be used in expressions regardless of the
language you use: the @value{GDBN} @code{@@} and @code{::} operators,
* OpenCL C:: OpenCL C
* Fortran:: Fortran
* Pascal:: Pascal
+* Rust:: Rust
* Modula-2:: Modula-2
* Ada:: Ada
@end menu
controls whether static members of Pascal objects are displayed.
@xref{Print Settings, pascal_static-members}.
+@node Rust
+@subsection Rust
+
+@value{GDBN} supports the @url{https://www.rust-lang.org/, Rust
+Programming Language}. Type- and value-printing, and expression
+parsing, are reasonably complete. However, there are a few
+peculiarities and holes to be aware of.
+
+@itemize @bullet
+@item
+Linespecs (@pxref{Specify Location}) are never relative to the current
+crate. Instead, they act as if there were a global namespace of
+crates, somewhat similar to the way @code{extern crate} behaves.
+
+That is, if @value{GDBN} is stopped at a breakpoint in a function in
+crate @samp{A}, module @samp{B}, then @code{break B::f} will attempt
+to set a breakpoint in a function named @samp{f} in a crate named
+@samp{B}.
+
+As a consequence of this approach, linespecs also cannot refer to
+items using @samp{self::} or @samp{super::}.
+
+@item
+Because @value{GDBN} implements Rust name-lookup semantics in
+expressions, it will sometimes prepend the current crate to a name.
+For example, if @value{GDBN} is stopped at a breakpoint in the crate
+@samp{K}, then @code{print ::x::y} will try to find the symbol
+@samp{K::x::y}.
+
+However, since it is useful to be able to refer to other crates when
+debugging, @value{GDBN} provides the @code{extern} extension to
+circumvent this. To use the extension, just put @code{extern} before
+a path expression to refer to the otherwise unavailable ``global''
+scope.
+
+In the above example, if you wanted to refer to the symbol @samp{y} in
+the crate @samp{x}, you would use @code{print extern x::y}.
+
+@item
+The Rust expression evaluator does not support ``statement-like''
+expressions such as @code{if} or @code{match}, or lambda expressions.
+
+@item
+Tuple expressions are not implemented.
+
+@item
+The Rust expression evaluator does not currently implement the
+@code{Drop} trait. Objects that may be created by the evaluator will
+never be destroyed.
+
+@item
+@value{GDBN} does not implement type inference for generics. In order
+to call generic functions or otherwise refer to generic items, you
+will have to specify the type parameters manually.
+
+@item
+@value{GDBN} currently uses the C@t{++} demangler for Rust. In most
+cases this does not cause any problems. However, in an expression
+context, completing a generic function name will give syntactically
+invalid results. This happens because Rust requires the @samp{::}
+operator between the function name and its generic arguments. For
+example, @value{GDBN} might provide a completion like
+@code{crate::f<u32>}, where the parser would require
+@code{crate::f::<u32>}.
+
+@item
+As of this writing, the Rust compiler (version 1.8) has a few holes in
+the debugging information it generates. These holes prevent certain
+features from being implemented by @value{GDBN}:
+@itemize @bullet
+
+@item
+Method calls cannot be made via traits.
+
+@item
+Trait objects cannot be created or inspected.
+
+@item
+Operator overloading is not implemented.
+
+@item
+When debugging in a monomorphized function, you cannot use the generic
+type names.
+
+@item
+The type @code{Self} is not available.
+
+@item
+@code{use} statements are not available, so some names may not be
+available in the crate.
+@end itemize
+@end itemize
+
@node Modula-2
@subsection Modula-2
(@value{GDBP})
@end smallexample
+@kindex maint info line-table
+@cindex listing @value{GDBN}'s internal line tables
+@cindex line tables, listing @value{GDBN}'s internal
+@item maint info line-table @r{[} @var{regexp} @r{]}
+
+List the @code{struct linetable} from all @code{struct symtab}
+instances whose name matches @var{regexp}. If @var{regexp} is not
+given, list the @code{struct linetable} from all @code{struct symtab}.
+
@kindex maint set symbol-cache-size
@cindex symbol cache size
@item maint set symbol-cache-size @var{size}
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 signal-event
+@item signal-event @var{id}
+This command signals an event with user-provided @var{id}. Used to resume
+crashing process when attached to it using MS-Windows JIT debugging (AeDebug).
+
+To use it, create or edit the following keys in
+@code{HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AeDebug} and/or
+@code{HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\AeDebug}
+(for x86_64 versions):
+
+@itemize @minus
+@item
+@code{Debugger} (REG_SZ) --- a command to launch the debugger.
+Suggested command is: @code{@var{fully-qualified-path-to-gdb.exe} -ex
+"attach %ld" -ex "signal-event %ld" -ex "continue"}.
+
+The first @code{%ld} will be replaced by the process ID of the
+crashing process, the second @code{%ld} will be replaced by the ID of
+the event that blocks the crashing process, waiting for @value{GDBN}
+to attach.
+
+@item
+@code{Auto} (REG_SZ) --- either @code{1} or @code{0}. @code{1} will
+make the system run debugger specified by the Debugger key
+automatically, @code{0} will cause a dialog box with ``OK'' and
+``Cancel'' buttons to appear, which allows the user to either
+terminate the crashing process (OK) or debug it (Cancel).
+@end itemize
+
@kindex set cygwin-exceptions
@cindex debugging the Cygwin DLL
@cindex Cygwin DLL, debugging
@menu
* ARM:: ARM
-* M32R/SDI:: Renesas M32R/SDI
* M68K:: Motorola M68K
* MicroBlaze:: Xilinx MicroBlaze
* MIPS Embedded:: MIPS Embedded
@end table
@end table
-@node M32R/SDI
-@subsection Renesas M32R/SDI
-
-The following commands are available for M32R/SDI:
-
-@table @code
-@item sdireset
-@kindex sdireset
-@cindex reset SDI connection, M32R
-This command resets the SDI connection.
-
-@item sdistatus
-@kindex sdistatus
-This command shows the SDI connection status.
-
-@item debug_chaos
-@kindex debug_chaos
-@cindex M32R/Chaos debugging
-Instructs the remote that M32R/Chaos debugging is to be used.
-
-@item use_debug_dma
-@kindex use_debug_dma
-Instructs the remote to use the DEBUG_DMA method of accessing memory.
-
-@item use_mon_code
-@kindex use_mon_code
-Instructs the remote to use the MON_CODE method of accessing memory.
-
-@item use_ib_break
-@kindex use_ib_break
-Instructs the remote to set breakpoints by IB break.
-
-@item use_dbt_break
-@kindex use_dbt_break
-Instructs the remote to set breakpoints by DBT.
-@end table
-
@node M68K
@subsection M68k
@node MIPS Embedded
@subsection @acronym{MIPS} Embedded
-@cindex @acronym{MIPS} boards
-@value{GDBN} can use the @acronym{MIPS} remote debugging protocol to talk to a
-@acronym{MIPS} board attached to a serial line. This is available when
-you configure @value{GDBN} with @samp{--target=mips-elf}.
-
-@need 1000
-Use these @value{GDBN} commands to specify the connection to your target board:
-
-@table @code
-@item target mips @var{port}
-@kindex target mips @var{port}
-To run a program on the board, start up @code{@value{GDBP}} with the
-name of your program as the argument. To connect to the board, use the
-command @samp{target mips @var{port}}, where @var{port} is the name of
-the serial port connected to the board. If the program has not already
-been downloaded to the board, you may use the @code{load} command to
-download it. You can then use all the usual @value{GDBN} commands.
-
-For example, this sequence connects to the target board through a serial
-port, and loads and runs a program called @var{prog} through the
-debugger:
-
-@smallexample
-host$ @value{GDBP} @var{prog}
-@value{GDBN} is free software and @dots{}
-(@value{GDBP}) target mips /dev/ttyb
-(@value{GDBP}) load @var{prog}
-(@value{GDBP}) run
-@end smallexample
-
-@item target mips @var{hostname}:@var{portnumber}
-On some @value{GDBN} host configurations, you can specify a TCP
-connection (for instance, to a serial line managed by a terminal
-concentrator) instead of a serial port, using the syntax
-@samp{@var{hostname}:@var{portnumber}}.
-
-@item target pmon @var{port}
-@kindex target pmon @var{port}
-PMON ROM monitor.
-
-@item target ddb @var{port}
-@kindex target ddb @var{port}
-NEC's DDB variant of PMON for Vr4300.
-
-@item target lsi @var{port}
-@kindex target lsi @var{port}
-LSI variant of PMON.
-
-@end table
-
-
@noindent
-@value{GDBN} also supports these special commands for @acronym{MIPS} targets:
+@value{GDBN} supports these special commands for @acronym{MIPS} targets:
@table @code
@item set mipsfpu double
As usual, you can inquire about the @code{mipsfpu} variable with
@samp{show mipsfpu}.
-
-@item set timeout @var{seconds}
-@itemx set retransmit-timeout @var{seconds}
-@itemx show timeout
-@itemx show retransmit-timeout
-@cindex @code{timeout}, @acronym{MIPS} protocol
-@cindex @code{retransmit-timeout}, @acronym{MIPS} protocol
-@kindex set timeout
-@kindex show timeout
-@kindex set retransmit-timeout
-@kindex show retransmit-timeout
-You can control the timeout used while waiting for a packet, in the @acronym{MIPS}
-remote protocol, with the @code{set timeout @var{seconds}} command. The
-default is 5 seconds. Similarly, you can control the timeout used while
-waiting for an acknowledgment of a packet with the @code{set
-retransmit-timeout @var{seconds}} command. The default is 3 seconds.
-You can inspect both values with @code{show timeout} and @code{show
-retransmit-timeout}. (These commands are @emph{only} available when
-@value{GDBN} is configured for @samp{--target=mips-elf}.)
-
-The timeout set by @code{set timeout} does not apply when @value{GDBN}
-is waiting for your program to stop. In that case, @value{GDBN} waits
-forever because it has no way of knowing how long the program is going
-to run before stopping.
-
-@item set syn-garbage-limit @var{num}
-@kindex set syn-garbage-limit@r{, @acronym{MIPS} remote}
-@cindex synchronize with remote @acronym{MIPS} target
-Limit the maximum number of characters @value{GDBN} should ignore when
-it tries to synchronize with the remote target. The default is 10
-characters. Setting the limit to -1 means there's no limit.
-
-@item show syn-garbage-limit
-@kindex show syn-garbage-limit@r{, @acronym{MIPS} remote}
-Show the current limit on the number of characters to ignore when
-trying to synchronize with the remote system.
-
-@item set monitor-prompt @var{prompt}
-@kindex set monitor-prompt@r{, @acronym{MIPS} remote}
-@cindex remote monitor prompt
-Tell @value{GDBN} to expect the specified @var{prompt} string from the
-remote monitor. The default depends on the target:
-@table @asis
-@item pmon target
-@samp{PMON}
-@item ddb target
-@samp{NEC010}
-@item lsi target
-@samp{PMON>}
-@end table
-
-@item show monitor-prompt
-@kindex show monitor-prompt@r{, @acronym{MIPS} remote}
-Show the current strings @value{GDBN} expects as the prompt from the
-remote monitor.
-
-@item set monitor-warnings
-@kindex set monitor-warnings@r{, @acronym{MIPS} remote}
-Enable or disable monitor warnings about hardware breakpoints. This
-has effect only for the @code{lsi} target. When on, @value{GDBN} will
-display warning messages whose codes are returned by the @code{lsi}
-PMON monitor for breakpoint commands.
-
-@item show monitor-warnings
-@kindex show monitor-warnings@r{, @acronym{MIPS} remote}
-Show the current setting of printing monitor warnings.
-
-@item pmon @var{command}
-@kindex pmon@r{, @acronym{MIPS} remote}
-@cindex send PMON command
-This command allows sending an arbitrary @var{command} string to the
-monitor. The monitor must be in debug mode for this to work.
@end table
@node PowerPC Embedded
@item show debug expression
Displays the current state of displaying debugging info about
@value{GDBN} expression parsing.
+@item set debug fbsd-lwp
+@cindex FreeBSD LWP debug messages
+Turns on or off debugging messages from the FreeBSD LWP debug support.
+@item show debug fbsd-lwp
+Show the current state of FreeBSD LWP debugging messages.
@item set debug frame
@cindex frame debugging info
Turns on or off display of @value{GDBN} frame debugging info. The
info.
@item set debug gnu-nat
@cindex @sc{gnu}/Hurd debug messages
-Turns on or off debugging messages from the @sc{gnu}/Hurd debug support.
+Turn on or off debugging messages from the @sc{gnu}/Hurd debug support.
@item show debug gnu-nat
Show the current state of @sc{gnu}/Hurd debugging messages.
@item set debug infrun
Displays the current state of @value{GDBN} inferior debugging.
@item set debug jit
@cindex just-in-time compilation, debugging messages
-Turns on or off debugging messages from JIT debug support.
+Turn on or off debugging messages from JIT debug support.
@item show debug jit
Displays the current state of @value{GDBN} JIT debugging.
@item set debug lin-lwp
@cindex @sc{gnu}/Linux LWP debug messages
@cindex Linux lightweight processes
-Turns on or off debugging messages from the Linux LWP debug support.
+Turn on or off debugging messages from the Linux LWP debug support.
@item show debug lin-lwp
Show the current state of Linux LWP debugging messages.
@item set debug linux-namespaces
@cindex @sc{gnu}/Linux namespaces debug messages
-Turns on or off debugging messages from the Linux namespaces debug support.
+Turn on or off debugging messages from the Linux namespaces debug support.
@item show debug linux-namespaces
Show the current state of Linux namespaces debugging messages.
@item set debug mach-o
reading of COFF/PE exported symbols.
@item set debug notification
@cindex remote async notification debugging info
-Turns on or off debugging messages about remote async notification.
+Turn on or off debugging messages about remote async notification.
The default is off.
@item show debug notification
Displays the current state of remote async notification debugging messages.
info.
@item set debug solib-frv
@cindex FR-V shared-library debugging
-Turns on or off debugging messages for FR-V shared-library code.
+Turn on or off debugging messages for FR-V shared-library code.
@item show debug solib-frv
Display the current state of FR-V shared-library code debugging
messages.
debugging info.
@item set debug xml
@cindex XML parser debugging
-Turns on or off debugging messages for built-in XML parsers.
+Turn on or off debugging messages for built-in XML parsers.
@item show debug xml
Displays the current state of XML debugging messages.
@end table
@end table
@cindex invoke another interpreter
-The interpreter being used by @value{GDBN} may not be dynamically
-switched at runtime. Although possible, this could lead to a very
-precarious situation. Consider an IDE using @sc{gdb/mi}. If a user
-enters the command "interpreter-set console" in a console view,
-@value{GDBN} would switch to using the console interpreter, rendering
-the IDE inoperable!
@kindex interpreter-exec
-Although you may only choose a single interpreter at startup, you may execute
-commands in any interpreter from the current interpreter using the appropriate
-command. If you are running the console interpreter, simply use the
-@code{interpreter-exec} command:
+You may execute commands in any interpreter from the current
+interpreter using the appropriate command. If you are running the
+console interpreter, simply use the @code{interpreter-exec} command:
@smallexample
interpreter-exec mi "-data-list-register-names"
@sc{gdb/mi} has a similar command, although it is only available in versions of
@value{GDBN} which support @sc{gdb/mi} version 2 (or greater).
+Note that @code{interpreter-exec} only changes the interpreter for the
+duration of the specified command. It does not change the interpreter
+permanently.
+
+@cindex start a new independent interpreter
+
+Although you may only choose a single interpreter at startup, it is
+possible to run an independent interpreter on a specified input/output
+device (usually a tty).
+
+For example, consider a debugger GUI or IDE that wants to provide a
+@value{GDBN} console view. It may do so by embedding a terminal
+emulator widget in its GUI, starting @value{GDBN} in the traditional
+command-line mode with stdin/stdout/stderr redirected to that
+terminal, and then creating an MI interpreter running on a specified
+input/output device. The console interpreter created by @value{GDBN}
+at startup handles commands the user types in the terminal widget,
+while the GUI controls and synchronizes state with @value{GDBN} using
+the separate MI interpreter.
+
+To start a new secondary @dfn{user interface} running MI, use the
+@code{new-ui} command:
+
+@kindex new-ui
+@cindex new user interface
+@smallexample
+new-ui @var{interpreter} @var{tty}
+@end smallexample
+
+The @var{interpreter} parameter specifies the interpreter to run.
+This accepts the same values as the @code{interpreter-exec} command.
+For example, @samp{console}, @samp{mi}, @samp{mi2}, etc. The
+@var{tty} parameter specifies the name of the bidirectional file the
+interpreter uses for input/output, usually the name of a
+pseudoterminal slave on Unix systems. For example:
+
+@smallexample
+(@value{GDBP}) new-ui mi /dev/pts/9
+@end smallexample
+
+@noindent
+runs an MI interpreter on @file{/dev/pts/9}.
+
@node TUI
@chapter @value{GDBN} Text User Interface
@cindex TUI
Note that if a breakpoint is emitted in the result record of a
command, then it will not also be emitted in an async record.
-@item =record-started,thread-group="@var{id}"
+@item =record-started,thread-group="@var{id}",method="@var{method}"[,format="@var{format}"]
@itemx =record-stopped,thread-group="@var{id}"
Execution log recording was either started or stopped on an
inferior. The @var{id} is the @value{GDBN} identifier of the thread
group corresponding to the affected inferior.
+The @var{method} field indicates the method used to record execution. If the
+method in use supports multiple recording formats, @var{format} will be present
+and contain the currently used format. @xref{Process Record and Replay}
+for existing method and format values.
+
@item =cmd-param-changed,param=@var{param},value=@var{value}
Reports that a parameter of the command @code{set @var{param}} is
changed to @var{value}. In the multi-word @code{set} command,
a recursive definition of the data type as stored in @value{GDBN}'s
data structures, including its flags and contained types.
+@kindex maint selftest
+@cindex self tests
+Run any self tests that were compiled in to @value{GDBN}. This will
+print a message showing how many tests were run, and how many failed.
+
@kindex maint set dwarf always-disassemble
@kindex maint show dwarf always-disassemble
@item maint set dwarf always-disassemble
encoding of @var{annex} is specific to @var{object}; it can supply
additional details about what data to access.
-Here are the specific requests of this form defined so far. All
+Reply:
+@table @samp
+@item m @var{data}
+Data @var{data} (@pxref{Binary Data}) has been read from the
+target. There may be more data at a higher address (although
+it is permitted to return @samp{m} even for the last valid
+block of data, as long as at least one byte of data was read).
+It is possible for @var{data} to have fewer bytes than the @var{length} in the
+request.
+
+@item l @var{data}
+Data @var{data} (@pxref{Binary Data}) has been read from the target.
+There is no more data to be read. It is possible for @var{data} to
+have fewer bytes than the @var{length} in the request.
+
+@item l
+The @var{offset} in the request is at the end of the data.
+There is no more data to be read.
+
+@item E00
+The request was malformed, or @var{annex} was invalid.
+
+@item E @var{nn}
+The offset was invalid, or there was an error encountered reading the data.
+The @var{nn} part is a hex-encoded @code{errno} value.
+
+@item @w{}
+An empty reply indicates the @var{object} string was not recognized by
+the stub, or that the object does not support reading.
+@end table
+
+Here are the specific requests of this form defined so far. All the
@samp{qXfer:@var{object}:read:@dots{}} requests use the same reply
-formats, listed below.
+formats, listed above.
@table @samp
@item qXfer:auxv:read::@var{offset},@var{length}
@end table
+@item qXfer:@var{object}:write:@var{annex}:@var{offset}:@var{data}@dots{}
+@cindex write data into object, remote request
+@anchor{qXfer write}
+Write uninterpreted bytes into the target's special data area
+identified by the keyword @var{object}, starting at @var{offset} bytes
+into the data. The binary-encoded data (@pxref{Binary Data}) to be
+written is given by @var{data}@dots{}. The content and encoding of @var{annex}
+is specific to @var{object}; it can supply additional details about what data
+to access.
+
Reply:
@table @samp
-@item m @var{data}
-Data @var{data} (@pxref{Binary Data}) has been read from the
-target. There may be more data at a higher address (although
-it is permitted to return @samp{m} even for the last valid
-block of data, as long as at least one byte of data was read).
-It is possible for @var{data} to have fewer bytes than the @var{length} in the
-request.
-
-@item l @var{data}
-Data @var{data} (@pxref{Binary Data}) has been read from the target.
-There is no more data to be read. It is possible for @var{data} to
-have fewer bytes than the @var{length} in the request.
-
-@item l
-The @var{offset} in the request is at the end of the data.
-There is no more data to be read.
+@item @var{nn}
+@var{nn} (hex encoded) is the number of bytes written.
+This may be fewer bytes than supplied in the request.
@item E00
The request was malformed, or @var{annex} was invalid.
@item E @var{nn}
-The offset was invalid, or there was an error encountered reading the data.
+The offset was invalid, or there was an error encountered writing the data.
The @var{nn} part is a hex-encoded @code{errno} value.
@item @w{}
-An empty reply indicates the @var{object} string was not recognized by
-the stub, or that the object does not support reading.
+An empty reply indicates the @var{object} string was not
+recognized by the stub, or that the object does not support writing.
@end table
-@item qXfer:@var{object}:write:@var{annex}:@var{offset}:@var{data}@dots{}
-@cindex write data into object, remote request
-@anchor{qXfer write}
-Write uninterpreted bytes into the target's special data area
-identified by the keyword @var{object}, starting at @var{offset} bytes
-into the data. The binary-encoded data (@pxref{Binary Data}) to be
-written is given by @var{data}@dots{}. The content and encoding of @var{annex}
-is specific to @var{object}; it can supply additional details about what data
-to access.
-
-Here are the specific requests of this form defined so far. All
+Here are the specific requests of this form defined so far. All the
@samp{qXfer:@var{object}:write:@dots{}} requests use the same reply
-formats, listed below.
+formats, listed above.
@table @samp
@item qXfer:siginfo:write::@var{offset}:@var{data}@dots{}
by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
@end table
-Reply:
-@table @samp
-@item @var{nn}
-@var{nn} (hex encoded) is the number of bytes written.
-This may be fewer bytes than supplied in the request.
-
-@item E00
-The request was malformed, or @var{annex} was invalid.
-
-@item E @var{nn}
-The offset was invalid, or there was an error encountered writing the data.
-The @var{nn} part is a hex-encoded @code{errno} value.
-
-@item @w{}
-An empty reply indicates the @var{object} string was not
-recognized by the stub, or that the object does not support writing.
-@end table
-
@item qXfer:@var{object}:@var{operation}:@dots{}
Requests of this form may be added in the future. When a stub does
not recognize the @var{object} keyword, or its support for
* Target Description Format:: The contents of a target description.
* Predefined Target Types:: Standard types available for target
descriptions.
+* Enum Target Types:: How to define enum target types.
* Standard Target Features:: Features @value{GDBN} knows about.
@end menu
interpret. The default interpretation is a two's complement integer,
but other types can be requested by name in the register description.
Some predefined types are provided by @value{GDBN} (@pxref{Predefined
-Target Types}), and the description can define additional composite types.
+Target Types}), and the description can define additional composite
+and enum types.
Each type element must have an @samp{id} attribute, which gives
a unique (within the containing @samp{<feature>}) name to the type.
@end smallexample
@cindex <struct>
+@cindex <flags>
If a register's value is composed from several separate values, define
-it with a structure type. There are two forms of the @samp{<struct>}
-element; a @samp{<struct>} element must either contain only bitfields
-or contain no bitfields. If the structure contains only bitfields,
-its total size in bytes must be specified, each bitfield must have an
-explicit start and end, and bitfields are automatically assigned an
-integer type. The field's @var{start} should be less than or
-equal to its @var{end}, and zero represents the least significant bit.
+it with either a structure type or a flags type.
+A flags type may only contain bitfields.
+A structure type may either contain only bitfields or contain no bitfields.
+If the value contains only bitfields, its total size in bytes must be
+specified.
+
+Non-bitfield values have a @var{name} and @var{type}.
@smallexample
-<struct id="@var{id}" size="@var{size}">
- <field name="@var{name}" start="@var{start}" end="@var{end}"/>
+<struct id="@var{id}">
+ <field name="@var{name}" type="@var{type}"/>
@dots{}
</struct>
@end smallexample
-If the structure contains no bitfields, then each field has an
-explicit type, and no implicit padding is added.
+Both @var{name} and @var{type} values are required.
+No implicit padding is added.
+
+Bitfield values have a @var{name}, @var{start}, @var{end} and @var{type}.
@smallexample
-<struct id="@var{id}">
- <field name="@var{name}" type="@var{type}"/>
+<struct id="@var{id}" size="@var{size}">
+ <field name="@var{name}" start="@var{start}" end="@var{end}" type="@var{type}"/>
@dots{}
</struct>
@end smallexample
-@cindex <flags>
-If a register's value is a series of single-bit flags, define it with
-a flags type. The @samp{<flags>} element has an explicit @var{size}
-and contains one or more @samp{<field>} elements. Each field has a
-@var{name}, a @var{start}, and an @var{end}. Only single-bit flags
-are supported.
-
@smallexample
<flags id="@var{id}" size="@var{size}">
- <field name="@var{name}" start="@var{start}" end="@var{end}"/>
+ <field name="@var{name}" start="@var{start}" end="@var{end}" type="@var{type}"/>
@dots{}
</flags>
@end smallexample
+The @var{name} value is required.
+Bitfield values may be named with the empty string, @samp{""},
+in which case the field is ``filler'' and its value is not printed.
+Not all bits need to be specified, so ``filler'' fields are optional.
+
+The @var{start} value is required, and @var{end} and @var{type}
+are optional.
+The field's @var{start} must be less than or equal to its @var{end},
+and zero represents the least significant bit.
+The default value of @var{end} is @var{start}, a single bit field.
+
+The default value of @var{type} depends on whether the
+@var{end} was specified. If @var{end} is specified then the default
+value of @var{type} is an unsigned integer. If @var{end} is unspecified
+then the default value of @var{type} is @code{bool}.
+
+Which to choose? Structures or flags?
+
+Registers defined with @samp{flags} have these advantages over
+defining them with @samp{struct}:
+
+@itemize @bullet
+@item
+Arithmetic may be performed on them as if they were integers.
+@item
+They are printed in a more readable fashion.
+@end itemize
+
+Registers defined with @samp{struct} have one advantage over
+defining them with @samp{flags}:
+
+@itemize @bullet
+@item
+One can fetch individual fields like in @samp{C}.
+
+@smallexample
+(gdb) print $my_struct_reg.field3
+$1 = 42
+@end smallexample
+
+@end itemize
+
@subsection Registers
@cindex <reg>
@table @code
+@item bool
+Boolean type, occupying a single bit.
+
@item int8
@itemx int16
@itemx int32
@end table
+@node Enum Target Types
+@section Enum Target Types
+@cindex target descriptions, enum types
+
+Enum target types are useful in @samp{struct} and @samp{flags}
+register descriptions. @xref{Target Description Format}.
+
+Enum types have a name, size and a list of name/value pairs.
+
+@smallexample
+<enum id="@var{id}" size="@var{size}">
+ <evalue name="@var{name}" value="@var{value}"/>
+ @dots{}
+</enum>
+@end smallexample
+
+Enums must be defined before they are used.
+
+@smallexample
+<enum id="levels_type" size="4">
+ <evalue name="low" value="0"/>
+ <evalue name="high" value="1"/>
+</enum>
+<flags id="flags_type" size="4">
+ <field name="X" start="0"/>
+ <field name="LEVEL" start="1" end="1" type="levels_type"/>
+</flags>
+<reg name="flags" bitsize="32" type="flags_type"/>
+@end smallexample
+
+Given that description, a value of 3 for the @samp{flags} register
+would be printed as:
+
+@smallexample
+(gdb) info register flags
+flags 0x3 [ X LEVEL=high ]
+@end smallexample
+
@node Standard Target Features
@section Standard Target Features
@cindex target descriptions, standard features
* MicroBlaze Features::
* MIPS Features::
* M68K Features::
+* NDS32 Features::
* Nios II Features::
* PowerPC Features::
* S/390 and System z Features::
@samp{fpiaddr}.
@end table
+@node NDS32 Features
+@subsection NDS32 Features
+@cindex target descriptions, NDS32 features
+
+The @samp{org.gnu.gdb.nds32.core} feature is required for NDS32
+targets. It should contain at least registers @samp{r0} through
+@samp{r10}, @samp{r15}, @samp{fp}, @samp{gp}, @samp{lp}, @samp{sp},
+and @samp{pc}.
+
+The @samp{org.gnu.gdb.nds32.fpu} feature is optional. If present,
+it should contain 64-bit double-precision floating-point registers
+@samp{fd0} through @emph{fdN}, which should be @samp{fd3}, @samp{fd7},
+@samp{fd15}, or @samp{fd31} based on the FPU configuration implemented.
+
+@emph{Note:} The first sixteen 64-bit double-precision floating-point
+registers are overlapped with the thirty-two 32-bit single-precision
+floating-point registers. The 32-bit single-precision registers, if
+not being listed explicitly, will be synthesized from halves of the
+overlapping 64-bit double-precision registers. Listing 32-bit
+single-precision registers explicitly is deprecated, and the
+support to it could be totally removed some day.
+
@node Nios II Features
@subsection Nios II Features
@cindex target descriptions, Nios II features
ignore any line that it does not recognize. An empty line marks the end
of this section.
-@c FIXME add some specific types of data
+@table @code
+@item R @var{size}
+Specifies the size of a register block in bytes. This is equal to the
+size of a @code{g} packet payload in the remote protocol. @var{size}
+is an ascii decimal number. There should be only one such line in
+a single trace file.
+
+@item status @var{status}
+Trace status. @var{status} has the same format as a @code{qTStatus}
+remote packet reply. There should be only one such line in a single trace
+file.
+
+@item tp @var{payload}
+Tracepoint definition. The @var{payload} has the same format as
+@code{qTfP}/@code{qTsP} remote packet reply payload. A single tracepoint
+may take multiple lines of definition, corresponding to the multiple
+reply packets.
+
+@item tsv @var{payload}
+Trace state variable definition. The @var{payload} has the same format as
+@code{qTfV}/@code{qTsV} remote packet reply payload. A single variable
+may take multiple lines of definition, corresponding to the multiple
+reply packets.
+
+@item tdesc @var{payload}
+Target description in XML format. The @var{payload} is a single line of
+the XML file. All such lines should be concatenated together to get
+the original XML file. This file is in the same format as @code{qXfer}
+@code{features} payload, and corresponds to the main @code{target.xml}
+file. Includes are not allowed.
+
+@end table
The trace frame section consists of a number of consecutive frames.
Each frame begins with a two-byte tracepoint number, followed by a
@item R @var{bytes}
Register block. The number and ordering of bytes matches that of a
@code{g} packet in the remote protocol. Note that these are the
-actual bytes, in target order and @value{GDBN} register order, not a
-hexadecimal encoding.
+actual bytes, in target order, not a hexadecimal encoding.
@item M @var{address} @var{length} @var{bytes}...
Memory block. This is a contiguous block of memory, at the 8-byte
@c pod2man highlights the right hand side of the @item lines.
@table @env
-@item break [@var{file}:]@var{functiop}
+@item break [@var{file}:]@var{function}
Set a breakpoint at @var{function} (in @var{file}).
@item run [@var{arglist}]
projects / deliverable / binutils-gdb.git / blobdiff