-@c Copyright (C) 2008-2017 Free Software Foundation, Inc.
+@c Copyright (C) 2008--2020 Free Software Foundation, Inc.
@c Permission is granted to copy, distribute and/or modify this document
@c under the terms of the GNU Free Documentation License, Version 1.3 or
@c any later version published by the Free Software Foundation; with the
You can extend @value{GDBN} using the @uref{http://www.python.org/,
Python programming language}. This feature is available only if
@value{GDBN} was configured using @option{--with-python}.
+@value{GDBN} can be built against either Python 2 or Python 3; which
+one you have depends on this configure-time option.
@cindex python directory
Python scripts used by @value{GDBN} should be installed in
@smallexample
(@value{GDBP}) python
-Type python script
-End with a line saying just "end".
>print 23
>end
23
The script name must end with @samp{.py} and @value{GDBN} must be configured
to recognize the script language based on filename extension using
the @code{script-extension} setting. @xref{Extending GDB, ,Extending GDB}.
-
-@item python execfile ("script-name")
-This method is based on the @code{execfile} Python built-in function,
-and thus is always available.
@end table
@node Python API
using Python.
* Lazy Strings In Python:: Python representation of lazy strings.
* Architectures In Python:: Python representation of architectures.
+* Registers In Python:: Python representation of registers.
+* TUI Windows In Python:: Implementing new TUI windows.
@end menu
@node Basic Python
@value{GDBN} automatically @code{import}s the @code{gdb} module for
use in all scripts evaluated by the @code{python} command.
+Some types of the @code{gdb} module come with a textual representation
+(accessible through the @code{repr} or @code{str} functions). These are
+offered for debugging purposes only, expect them to change over time.
+
@findex gdb.PYTHONDIR
@defvar gdb.PYTHONDIR
A string containing the python directory (@pxref{Python}).
@code{gdb.breakpoints} returns an empty sequence in this case.
@end defun
+@defun gdb.rbreak (regex @r{[}, minsyms @r{[}, throttle, @r{[}, symtabs @r{]]]})
+Return a Python list holding a collection of newly set
+@code{gdb.Breakpoint} objects matching function names defined by the
+@var{regex} pattern. If the @var{minsyms} keyword is @code{True}, all
+system functions (those not explicitly defined in the inferior) will
+also be included in the match. The @var{throttle} keyword takes an
+integer that defines the maximum number of pattern matches for
+functions matched by the @var{regex} pattern. If the number of
+matches exceeds the integer value of @var{throttle}, a
+@code{RuntimeError} will be raised and no breakpoints will be created.
+If @var{throttle} is not defined then there is no imposed limit on the
+maximum number of matches and breakpoints to be created. The
+@var{symtabs} keyword takes a Python iterable that yields a collection
+of @code{gdb.Symtab} objects and will restrict the search to those
+functions only contained within the @code{gdb.Symtab} objects.
+@end defun
+
@findex gdb.parameter
@defun gdb.parameter (parameter)
Return the value of a @value{GDBN} @var{parameter} given by its name,
@code{gdb.Value} (@pxref{Values From Inferior}).
@end defun
+@findex gdb.convenience_variable
+@defun gdb.convenience_variable (name)
+Return the value of the convenience variable (@pxref{Convenience
+Vars}) named @var{name}. @var{name} must be a string. The name
+should not include the @samp{$} that is used to mark a convenience
+variable in an expression. If the convenience variable does not
+exist, then @code{None} is returned.
+@end defun
+
+@findex gdb.set_convenience_variable
+@defun gdb.set_convenience_variable (name, value)
+Set the value of the convenience variable (@pxref{Convenience Vars})
+named @var{name}. @var{name} must be a string. The name should not
+include the @samp{$} that is used to mark a convenience variable in an
+expression. If @var{value} is @code{None}, then the convenience
+variable is removed. Otherwise, if @var{value} is not a
+@code{gdb.Value} (@pxref{Values From Inferior}), it is is converted
+using the @code{gdb.Value} constructor.
+@end defun
+
@findex gdb.parse_and_eval
@defun gdb.parse_and_eval (expression)
Parse @var{expression}, which must be a string, as an expression in
This function can be useful when implementing a new command
(@pxref{Commands In Python}), as it provides a way to parse the
command's argument as an expression. It is also useful simply to
-compute values, for example, it is the only way to get the value of a
-convenience variable (@pxref{Convenience Vars}) as a @code{gdb.Value}.
+compute values.
@end defun
@findex gdb.find_pc_line
@var{pc} value. @xref{Symbol Tables In Python}. If an invalid
value of @var{pc} is passed as an argument, then the @code{symtab} and
@code{line} attributes of the returned @code{gdb.Symtab_and_line} object
-will be @code{None} and 0 respectively.
+will be @code{None} and 0 respectively. This is identical to
+@code{gdb.current_progspace().find_pc_line(pc)} and is included for
+historical compatibility.
@end defun
@findex gdb.post_event
@findex gdb.solib_name
@defun gdb.solib_name (address)
Return the name of the shared library holding the given @var{address}
-as a string, or @code{None}.
+as a string, or @code{None}. This is identical to
+@code{gdb.current_progspace().solib_name(address)} and is included for
+historical compatibility.
@end defun
@findex gdb.decode_line
-@defun gdb.decode_line @r{[}expression@r{]}
+@defun gdb.decode_line (@r{[}expression@r{]})
Return locations of the line specified by @var{expression}, or of the
current line if no argument was given. This function returns a Python
tuple containing two elements. The first element contains a string
statement closest to where the @value{GDBN} error occured as the
traceback.
-@findex gdb.GdbError
-When implementing @value{GDBN} commands in Python via @code{gdb.Command},
-it is useful to be able to throw an exception that doesn't cause a
-traceback to be printed. For example, the user may have invoked the
-command incorrectly. Use the @code{gdb.GdbError} exception
-to handle this case. Example:
+
+When implementing @value{GDBN} commands in Python via
+@code{gdb.Command}, or functions via @code{gdb.Function}, it is useful
+to be able to throw an exception that doesn't cause a traceback to be
+printed. For example, the user may have invoked the command
+incorrectly. @value{GDBN} provides a special exception class that can
+be used for this purpose.
+
+@ftable @code
+@item gdb.GdbError
+When thrown from a command or function, this exception will cause the
+command or function to fail, but the Python stack will not be
+displayed. @value{GDBN} does not throw this exception itself, but
+rather recognizes it when thrown from user Python code. Example:
@smallexample
(gdb) python
(gdb) hello-world 42
hello-world takes no arguments
@end smallexample
+@end ftable
@node Values From Inferior
@subsubsection Values From Inferior
@end defvar
@defvar Value.dynamic_type
-The dynamic type of this @code{gdb.Value}. This uses C@t{++} run-time
-type information (@acronym{RTTI}) to determine the dynamic type of the
-value. If this value is of class type, it will return the class in
-which the value is embedded, if any. If this value is of pointer or
-reference to a class type, it will compute the dynamic type of the
-referenced object, and return a pointer or reference to that type,
-respectively. In all other cases, it will return the value's static
-type.
+The dynamic type of this @code{gdb.Value}. This uses the object's
+virtual table and the C@t{++} run-time type information
+(@acronym{RTTI}) to determine the dynamic type of the value. If this
+value is of class type, it will return the class in which the value is
+embedded, if any. If this value is of pointer or reference to a class
+type, it will compute the dynamic type of the referenced object, and
+return a pointer or reference to that type, respectively. In all
+other cases, it will return the value's static type.
Note that this feature will only work when debugging a C@t{++} program
that includes @acronym{RTTI} for the object in question. Otherwise,
@end table
@end defun
+@defun Value.__init__ (@var{val}, @var{type})
+This second form of the @code{gdb.Value} constructor returns a
+@code{gdb.Value} of type @var{type} where the value contents are taken
+from the Python buffer object specified by @var{val}. The number of
+bytes in the Python buffer object must be greater than or equal to the
+size of @var{type}.
+@end defun
+
@defun Value.cast (type)
Return a new instance of @code{gdb.Value} that is the result of
casting this instance to the type described by @var{type}, which must
value pointed to by @code{foo}.
A similar function @code{Value.referenced_value} exists which also
-returns @code{gdb.Value} objects corresonding to the values pointed to
+returns @code{gdb.Value} objects corresponding to the values pointed to
by pointer values (and additionally, values referenced by reference
values). However, the behavior of @code{Value.dereference}
differs from @code{Value.referenced_value} by the fact that the
operator were used. Consult a C@t{++} reference for details.
@end defun
+@defun Value.format_string (...)
+Convert a @code{gdb.Value} to a string, similarly to what the @code{print}
+command does. Invoked with no arguments, this is equivalent to calling
+the @code{str} function on the @code{gdb.Value}. The representation of
+the same value may change across different versions of @value{GDBN}, so
+you shouldn't, for instance, parse the strings returned by this method.
+
+All the arguments are keyword only. If an argument is not specified, the
+current global default setting is used.
+
+@table @code
+@item raw
+@code{True} if pretty-printers (@pxref{Pretty Printing}) should not be
+used to format the value. @code{False} if enabled pretty-printers
+matching the type represented by the @code{gdb.Value} should be used to
+format it.
+
+@item pretty_arrays
+@code{True} if arrays should be pretty printed to be more convenient to
+read, @code{False} if they shouldn't (see @code{set print array} in
+@ref{Print Settings}).
+
+@item pretty_structs
+@code{True} if structs should be pretty printed to be more convenient to
+read, @code{False} if they shouldn't (see @code{set print pretty} in
+@ref{Print Settings}).
+
+@item array_indexes
+@code{True} if array indexes should be included in the string
+representation of arrays, @code{False} if they shouldn't (see @code{set
+print array-indexes} in @ref{Print Settings}).
+
+@item symbols
+@code{True} if the string representation of a pointer should include the
+corresponding symbol name (if one exists), @code{False} if it shouldn't
+(see @code{set print symbol} in @ref{Print Settings}).
+
+@item unions
+@code{True} if unions which are contained in other structures or unions
+should be expanded, @code{False} if they shouldn't (see @code{set print
+union} in @ref{Print Settings}).
+
+@item deref_refs
+@code{True} if C@t{++} references should be resolved to the value they
+refer to, @code{False} (the default) if they shouldn't. Note that, unlike
+for the @code{print} command, references are not automatically expanded
+when using the @code{format_string} method or the @code{str}
+function. There is no global @code{print} setting to change the default
+behaviour.
+
+@item actual_objects
+@code{True} if the representation of a pointer to an object should
+identify the @emph{actual} (derived) type of the object rather than the
+@emph{declared} type, using the virtual function table. @code{False} if
+the @emph{declared} type should be used. (See @code{set print object} in
+@ref{Print Settings}).
+
+@item static_fields
+@code{True} if static members should be included in the string
+representation of a C@t{++} object, @code{False} if they shouldn't (see
+@code{set print static-members} in @ref{Print Settings}).
+
+@item max_elements
+Number of array elements to print, or @code{0} to print an unlimited
+number of elements (see @code{set print elements} in @ref{Print
+Settings}).
+
+@item max_depth
+The maximum depth to print for nested structs and unions, or @code{-1}
+to print an unlimited number of elements (see @code{set print
+max-depth} in @ref{Print Settings}).
+
+@item repeat_threshold
+Set the threshold for suppressing display of repeated array elements, or
+@code{0} to represent all elements, even if repeated. (See @code{set
+print repeats} in @ref{Print Settings}).
+
+@item format
+A string containing a single character representing the format to use for
+the returned string. For instance, @code{'x'} is equivalent to using the
+@value{GDBN} command @code{print} with the @code{/x} option and formats
+the value as a hexadecimal number.
+@end table
+@end defun
+
@defun Value.string (@r{[}encoding@r{[}, errors@r{[}, length@r{]]]})
If this @code{gdb.Value} represents a string, then this method
converts the contents to a Python string. Otherwise, this method will
An instance of @code{Type} has the following attributes:
+@defvar Type.alignof
+The alignment of this type, in bytes. Type alignment comes from the
+debugging information; if it was not specified, then @value{GDBN} will
+use the relevant ABI to try to determine the alignment. In some
+cases, even this is not possible, and zero will be returned.
+@end defvar
+
@defvar Type.code
The type code for this type. The type code will be one of the
@code{TYPE_CODE_} constants defined below.
@end defvar
+@defvar Type.dynamic
+A boolean indicating whether this type is dynamic. In some
+situations, such as Rust @code{enum} types or Ada variant records, the
+concrete type of a value may vary depending on its contents. That is,
+the declared type of a variable, or the type returned by
+@code{gdb.lookup_type} may be dynamic; while the type of the
+variable's value will be a concrete instance of that dynamic type.
+
+For example, consider this code:
+@smallexample
+int n;
+int array[n];
+@end smallexample
+
+Here, at least conceptually (whether your compiler actually does this
+is a separate issue), examining @w{@code{gdb.lookup_symbol("array", ...).type}}
+could yield a @code{gdb.Type} which reports a size of @code{None}.
+This is the dynamic type.
+
+However, examining @code{gdb.parse_and_eval("array").type} would yield
+a concrete type, whose length would be known.
+@end defvar
+
@defvar Type.name
The name of this type. If this type has no name, then @code{None}
is returned.
@defvar Type.sizeof
The size of this type, in target @code{char} units. Usually, a
target's @code{char} type will be an 8-bit byte. However, on some
-unusual platforms, this type may have a different size.
+unusual platforms, this type may have a different size. A dynamic
+type may not have a fixed size; in this case, this attribute's value
+will be @code{None}.
@end defvar
@defvar Type.tag
@code{None} is returned.
@end defvar
+@defvar Type.objfile
+The @code{gdb.Objfile} that this type was defined in, or @code{None} if
+there is no associated objfile.
+@end defvar
+
The following methods are provided:
@defun Type.fields ()
@item bitpos
This attribute is not available for @code{enum} or @code{static}
(as in C@t{++}) fields. The value is the position, counting
-in bits, from the start of the containing type.
+in bits, from the start of the containing type. Note that, in a
+dynamic type, the position of a field may not be constant. In this
+case, the value will be @code{None}. Also, a dynamic type may have
+fields that do not appear in a corresponding concrete type.
@item enumval
This attribute is only available for @code{enum} fields, and its value
@item gdb.TYPE_CODE_REF
A reference type.
+@vindex TYPE_CODE_RVALUE_REF
+@item gdb.TYPE_CODE_RVALUE_REF
+A C@t{++}11 rvalue reference type.
+
@vindex TYPE_CODE_CHAR
@item gdb.TYPE_CODE_CHAR
A character type.
@subsubsection Pretty Printing API
@cindex python pretty printing api
-An example output is provided (@pxref{Pretty Printing}).
-
A pretty-printer is just an object that holds a value and implements a
-specific interface, defined here.
+specific interface, defined here. An example output is provided
+(@pxref{Pretty Printing}).
@defun pretty_printer.children (self)
@value{GDBN} will call this method on a pretty-printer to compute the
This method is optional. If it does not exist, @value{GDBN} will act
as though the value has no children.
+
+For efficiency, the @code{children} method should lazily compute its
+results. This will let @value{GDBN} read as few elements as
+necessary, for example when various print settings (@pxref{Print
+Settings}) or @code{-var-list-children} (@pxref{GDB/MI Variable
+Objects}) limit the number of elements to be displayed.
+
+Children may be hidden from display based on the value of @samp{set
+print max-depth} (@pxref{Print Settings}).
@end defun
@defun pretty_printer.display_hint (self)
printed.
This method is optional. If it does exist, this method must return a
-string.
+string or the special value @code{None}.
Some display hints are predefined by @value{GDBN}:
adding quotation marks, possibly escaping some characters, respecting
@code{set print elements}, and the like.
@end table
+
+The special value @code{None} causes @value{GDBN} to apply the default
+display rules.
@end defun
@defun pretty_printer.to_string (self)
@subsubsection Selecting Pretty-Printers
@cindex selecting python pretty-printers
+@value{GDBN} provides several ways to register a pretty-printer:
+globally, per program space, and per objfile. When choosing how to
+register your pretty-printer, a good rule is to register it with the
+smallest scope possible: that is prefer a specific objfile first, then
+a program space, and only register a printer globally as a last
+resort.
+
+@findex gdb.pretty_printers
+@defvar gdb.pretty_printers
The Python list @code{gdb.pretty_printers} contains an array of
functions or callable objects that have been registered via addition
as a pretty-printer. Printers in this list are called @code{global}
printers, they're available when debugging all inferiors.
+@end defvar
+
Each @code{gdb.Progspace} contains a @code{pretty_printers} attribute.
Each @code{gdb.Objfile} also contains a @code{pretty_printers}
attribute.
inferior changed.
@node Frame Filter API
-@subsubsection Filtering Frames.
+@subsubsection Filtering Frames
@cindex frame filters api
Frame filters are Python objects that manipulate the visibility of a
recommended practice to assume zero is the lowest priority that a
frame filter can be assigned. Frame filters that have the same
priority are executed in unsorted order in that priority slot. This
-attribute is mandatory.
+attribute is mandatory. 100 is a good default priority.
@end defvar
@node Frame Decorator API
-@subsubsection Decorating Frames.
+@subsubsection Decorating Frames
@cindex frame decorator api
Frame decorators are sister objects to frame filters (@pxref{Frame
recommended that other frame decorators inherit and extend this
object, and only to override the methods needed.
+@tindex gdb.FrameDecorator
+@code{FrameDecorator} is defined in the Python module
+@code{gdb.FrameDecorator}, so your code can import it like:
+@smallexample
+from gdb.FrameDecorator import FrameDecorator
+@end smallexample
+
@defun FrameDecorator.elided (self)
The @code{elided} method groups frames together in a hierarchical
unwinders in Python uses this object to return frame's ID and previous
frame registers when @value{GDBN} core asks for them.
+An unwinder should do as little work as possible. Some otherwise
+innocuous operations can cause problems (even crashes, as this code is
+not not well-hardened yet). For example, making an inferior call from
+an unwinder is unadvisable, as an inferior call will reset
+@value{GDBN}'s stack unwinding process, potentially causing re-entrant
+unwinding.
+
@subheading Unwinder Input
An object passed to an unwinder (a @code{gdb.PendingFrame} instance)
provides a method to read frame's registers:
@defun PendingFrame.read_register (reg)
-This method returns the contents of the register @var{regn} in the
+This method returns the contents of the register @var{reg} in the
frame as a @code{gdb.Value} object. @var{reg} can be either a
register number or a register name; the values are platform-specific.
They are usually found in the corresponding
-@file{@var{platform}-tdep.h} file in the @value{GDBN} source tree.
+@file{@var{platform}-tdep.h} file in the @value{GDBN} source tree. If
+@var{reg} does not name a register for the current architecture, this
+method will throw an exception.
+
+Note that this method will always return a @code{gdb.Value} for a
+valid register name. This does not mean that the value will be valid.
+For example, you may request a register that an earlier unwinder could
+not unwind---the value will be unavailable. Instead, the
+@code{gdb.Value} returned from this method will be lazy; that is, its
+underlying bits will not be fetched until it is first used. So,
+attempting to use such a value will cause an exception at the point of
+use.
+
+The type of the returned @code{gdb.Value} depends on the register and
+the architecture. It is common for registers to have a scalar type,
+like @code{long long}; but many other types are possible, such as
+pointer, pointer-to-function, floating point or vector types.
@end defun
It also provides a factory method to create a @code{gdb.UnwindInfo}
determine which function will be used, as follows:
@table @code
-@item sp, pc, special
-@code{frame_id_build_special (@var{frame_id}.sp, @var{frame_id}.pc, @var{frame_id}.special)}
-
@item sp, pc
-@code{frame_id_build (@var{frame_id}.sp, @var{frame_id}.pc)}
+The frame is identified by the given stack address and PC. The stack
+address must be chosen so that it is constant throughout the lifetime
+of the frame, so a typical choice is the value of the stack pointer at
+the start of the function---in the DWARF standard, this would be the
+``Call Frame Address''.
-This is the most common case.
+This is the most common case by far. The other cases are documented
+for completeness but are only useful in specialized situations.
+
+@item sp, pc, special
+The frame is identified by the stack address, the PC, and a
+``special'' address. The special address is used on architectures
+that can have frames that do not change the stack, but which are still
+distinct, for example the IA-64, which has a second stack for
+registers. Both @var{sp} and @var{special} must be constant
+throughout the lifetime of the frame.
@item sp
-@code{frame_id_build_wild (@var{frame_id}.sp)}
+The frame is identified by the stack address only. Any other stack
+frame with a matching @var{sp} will be considered to match this frame.
+Inside gdb, this is called a ``wild frame''. You will never need
+this.
@end table
-The attribute values should be @code{gdb.Value}
+
+Each attribute value should be an instance of @code{gdb.Value}.
@end defun
+@defun PendingFrame.architecture ()
+Return the @code{gdb.Architecture} (@pxref{Architectures In Python})
+for this @code{gdb.PendingFrame}. This represents the architecture of
+the particular frame being unwound.
+@end defun
+
@subheading Unwinder Output: UnwindInfo
Use @code{PendingFrame.create_unwind_info} method described above to
class MyUnwinder(Unwinder):
def __init__(....):
- supe(MyUnwinder, self).__init___(<expects unwinder name argument>)
+ super(MyUnwinder, self).__init___(<expects unwinder name argument>)
def __call__(pending_frame):
if not <we recognize frame>:
@findex gdb.Inferior
Programs which are being run under @value{GDBN} are called inferiors
-(@pxref{Inferiors and Programs}). Python scripts can access
+(@pxref{Inferiors Connections and Programs}). Python scripts can access
information about and manipulate inferiors controlled by @value{GDBN}
via objects of the @code{gdb.Inferior} class.
started by @value{GDBN} itself.
@end defvar
+@defvar Inferior.progspace
+The inferior's program space. @xref{Progspaces In Python}.
+@end defvar
+
A @code{gdb.Inferior} object has the following methods:
@defun Inferior.is_valid ()
return an empty tuple.
@end defun
+@defun Inferior.architecture ()
+Return the @code{gdb.Architecture} (@pxref{Architectures In Python})
+for this inferior. This represents the architecture of the inferior
+as a whole. Some platforms can have multiple architectures in a
+single address space, so this may not match the architecture of a
+particular frame (@pxref{Frames In Python}).
+@end defun
+
@findex Inferior.read_memory
@defun Inferior.read_memory (address, length)
Read @var{length} addressable memory units from the inferior, starting at
@var{address}. Returns a buffer object, which behaves much like an array
or a string. It can be modified and given to the
-@code{Inferior.write_memory} function. In @code{Python} 3, the return
+@code{Inferior.write_memory} function. In Python 3, the return
value is a @code{memoryview} object.
@end defun
the pattern could not be found.
@end defun
+@findex Inferior.thread_from_handle
+@findex Inferior.thread_from_thread_handle
+@defun Inferior.thread_from_handle (handle)
+Return the thread object corresponding to @var{handle}, a thread
+library specific data structure such as @code{pthread_t} for pthreads
+library implementations.
+
+The function @code{Inferior.thread_from_thread_handle} provides
+the same functionality, but use of @code{Inferior.thread_from_thread_handle}
+is deprecated.
+@end defun
+
@node Events In Python
@subsubsection Events In Python
@cindex inferior events in Python
been cleared. @xref{Progspaces In Python}.
@end defvar
-@item events.inferior_call_pre
-Emits @code{gdb.InferiorCallPreEvent} which indicates that a function in
-the inferior is about to be called.
+@item events.inferior_call
+Emits events just before and after a function in the inferior is
+called by @value{GDBN}. Before an inferior call, this emits an event
+of type @code{gdb.InferiorCallPreEvent}, and after an inferior call,
+this emits an event of type @code{gdb.InferiorCallPostEvent}.
+
+@table @code
+@tindex gdb.InferiorCallPreEvent
+@item @code{gdb.InferiorCallPreEvent}
+Indicates that a function in the inferior is about to be called.
@defvar InferiorCallPreEvent.ptid
The thread in which the call will be run.
The location of the function to be called.
@end defvar
-@item events.inferior_call_post
-Emits @code{gdb.InferiorCallPostEvent} which indicates that a function in
-the inferior has returned.
+@tindex gdb.InferiorCallPostEvent
+@item @code{gdb.InferiorCallPostEvent}
+Indicates that a function in the inferior has just been called.
@defvar InferiorCallPostEvent.ptid
The thread in which the call was run.
@defvar InferiorCallPostEvent.address
The location of the function that was called.
@end defvar
+@end table
@item events.memory_changed
Emits @code{gdb.MemoryChangedEvent} which indicates that the memory of the
invalid state; that is, the @code{is_valid} method will return
@code{False}.
+@item events.before_prompt
+This event carries no payload. It is emitted each time @value{GDBN}
+presents a prompt to the user.
+
+@item events.new_inferior
+This is emitted when a new inferior is created. Note that the
+inferior is not necessarily running; in fact, it may not even have an
+associated executable.
+
+The event is of type @code{gdb.NewInferiorEvent}. This has a single
+attribute:
+
+@defvar NewInferiorEvent.inferior
+The new inferior, a @code{gdb.Inferior} object.
+@end defvar
+
+@item events.inferior_deleted
+This is emitted when an inferior has been deleted. Note that this is
+not the same as process exit; it is notified when the inferior itself
+is removed, say via @code{remove-inferiors}.
+
+The event is of type @code{gdb.InferiorDeletedEvent}. This has a single
+attribute:
+
+@defvar NewInferiorEvent.inferior
+The inferior that is being removed, a @code{gdb.Inferior} object.
+@end defvar
+
+@item events.new_thread
+This is emitted when @value{GDBN} notices a new thread. The event is of
+type @code{gdb.NewThreadEvent}, which extends @code{gdb.ThreadEvent}.
+This has a single attribute:
+
+@defvar NewThreadEvent.inferior_thread
+The new thread.
+@end defvar
+
@end table
@node Threads In Python
is no selected thread, this will return @code{None}.
@end defun
+To get the list of threads for an inferior, use the @code{Inferior.threads()}
+method. @xref{Inferiors In Python}.
+
A @code{gdb.InferiorThread} object has the following attributes:
@defvar InferiorThread.name
Return a Boolean indicating whether the thread is exited.
@end defun
+@defun InferiorThread.handle ()
+Return the thread object's handle, represented as a Python @code{bytes}
+object. A @code{gdb.Value} representation of the handle may be
+constructed via @code{gdb.Value(bufobj, type)} where @var{bufobj} is
+the Python @code{bytes} representation of the handle and @var{type} is
+a @code{gdb.Type} for the handle type.
+@end defun
+
@node Recordings In Python
@subsubsection Recordings In Python
@cindex recordings in python
A @code{gdb.Record} object has the following attributes:
-@defvar Record.ptid
-ID of the thread associated with this object as a tuple of three integers. The
-first is the Process ID (PID); the second is the Lightweight Process ID (LWPID),
-and the third is the Thread ID (TID). Either the LWPID or TID may be 0, which
-indicates that the operating system does not use that identifier.
-@end defvar
-
@defvar Record.method
A string with the current recording method, e.g.@: @code{full} or
@code{btrace}.
Move the replay position to the given @var{instruction}.
@end defun
-The attributes and methods of instruction objects depend on the current
-recording method. Currently, only btrace instructions are supported.
+The common @code{gdb.Instruction} class that recording method specific
+instruction objects inherit from, has the following attributes:
-A @code{gdb.BtraceInstruction} object has the following attributes:
+@defvar Instruction.pc
+An integer representing this instruction's address.
+@end defvar
-@defvar BtraceInstruction.number
-An integer identifying this instruction. @var{number} corresponds to
-the numbers seen in @code{record instruction-history}
-(@pxref{Process Record and Replay}).
+@defvar Instruction.data
+A buffer with the raw instruction data. In Python 3, the return value is a
+@code{memoryview} object.
@end defvar
-@defvar BtraceInstruction.error
-An integer identifying the error code for gaps in the history.
-@code{None} for regular instructions.
+@defvar Instruction.decoded
+A human readable string with the disassembled instruction.
@end defvar
-@defvar BtraceInstruction.sal
-A @code{gdb.Symtab_and_line} object representing the associated symtab
-and line of this instruction. May be @code{None} if the instruction
-is a gap.
+@defvar Instruction.size
+The size of the instruction in bytes.
@end defvar
-@defvar BtraceInstruction.pc
-An integer representing this instruction's address. May be @code{None}
-if the instruction is a gap or the debug symbols could not be read.
+Additionally @code{gdb.RecordInstruction} has the following attributes:
+
+@defvar RecordInstruction.number
+An integer identifying this instruction. @code{number} corresponds to
+the numbers seen in @code{record instruction-history}
+(@pxref{Process Record and Replay}).
@end defvar
-@defvar BtraceInstruction.data
-A buffer with the raw instruction data. May be @code{None} if the
-instruction is a gap.
+@defvar RecordInstruction.sal
+A @code{gdb.Symtab_and_line} object representing the associated symtab
+and line of this instruction. May be @code{None} if no debug information is
+available.
@end defvar
-@defvar BtraceInstruction.decoded
-A human readable string with the disassembled instruction. Contains the
-error message for gaps.
+@defvar RecordInstruction.is_speculative
+A boolean indicating whether the instruction was executed speculatively.
@end defvar
-@defvar BtraceInstruction.size
-The size of the instruction in bytes. Will be @code{None} if the
-instruction is a gap.
+If an error occured during recording or decoding a recording, this error is
+represented by a @code{gdb.RecordGap} object in the instruction list. It has
+the following attributes:
+
+@defvar RecordGap.number
+An integer identifying this gap. @code{number} corresponds to the numbers seen
+in @code{record instruction-history} (@pxref{Process Record and Replay}).
@end defvar
-@defvar BtraceInstruction.is_speculative
-A boolean indicating whether the instruction was executed
-speculatively. Will be @code{None} for gaps.
+@defvar RecordGap.error_code
+A numerical representation of the reason for the gap. The value is specific to
+the current recording method.
@end defvar
-The attributes and methods of function call objects depend on the
-current recording format. Currently, only btrace function calls are
-supported.
+@defvar RecordGap.error_string
+A human readable string with the reason for the gap.
+@end defvar
-A @code{gdb.BtraceFunctionCall} object has the following attributes:
+A @code{gdb.RecordFunctionSegment} object has the following attributes:
-@defvar BtraceFunctionCall.number
-An integer identifying this function call. @var{number} corresponds to
+@defvar RecordFunctionSegment.number
+An integer identifying this function segment. @code{number} corresponds to
the numbers seen in @code{record function-call-history}
(@pxref{Process Record and Replay}).
@end defvar
-@defvar BtraceFunctionCall.symbol
+@defvar RecordFunctionSegment.symbol
A @code{gdb.Symbol} object representing the associated symbol. May be
-@code{None} if the function call is a gap or the debug symbols could
-not be read.
+@code{None} if no debug information is available.
@end defvar
-@defvar BtraceFunctionCall.level
+@defvar RecordFunctionSegment.level
An integer representing the function call's stack level. May be
@code{None} if the function call is a gap.
@end defvar
-@defvar BtraceFunctionCall.instructions
-A list of @code{gdb.BtraceInstruction} objects associated with this function
-call.
+@defvar RecordFunctionSegment.instructions
+A list of @code{gdb.RecordInstruction} or @code{gdb.RecordGap} objects
+associated with this function call.
@end defvar
-@defvar BtraceFunctionCall.up
-A @code{gdb.BtraceFunctionCall} object representing the caller's
+@defvar RecordFunctionSegment.up
+A @code{gdb.RecordFunctionSegment} object representing the caller's
function segment. If the call has not been recorded, this will be the
function segment to which control returns. If neither the call nor the
return have been recorded, this will be @code{None}.
@end defvar
-@defvar BtraceFunctionCall.prev_sibling
-A @code{gdb.BtraceFunctionCall} object representing the previous
+@defvar RecordFunctionSegment.prev
+A @code{gdb.RecordFunctionSegment} object representing the previous
segment of this function call. May be @code{None}.
@end defvar
-@defvar BtraceFunctionCall.next_sibling
-A @code{gdb.BtraceFunctionCall} object representing the next segment of
+@defvar RecordFunctionSegment.next
+A @code{gdb.RecordFunctionSegment} object representing the next segment of
this function call. May be @code{None}.
@end defvar
@kbd{help tracepoints} at the @value{GDBN} prompt to see a list of
commands in this category.
+@findex COMMAND_TUI
+@findex gdb.COMMAND_TUI
+@item gdb.COMMAND_TUI
+The command has to do with the text user interface (@pxref{TUI}).
+Type @kbd{help tui} at the @value{GDBN} prompt to see a list of
+commands in this category.
+
@findex COMMAND_USER
@findex gdb.COMMAND_USER
@item gdb.COMMAND_USER
attribute. @value{GDBN} does validation when assignments are made.
@end defvar
-There are two methods that should be implemented in any
-@code{Parameter} class. These are:
+There are two methods that may be implemented in any @code{Parameter}
+class. These are:
@defun Parameter.get_set_string (self)
-@value{GDBN} will call this method when a @var{parameter}'s value has
-been changed via the @code{set} API (for example, @kbd{set foo off}).
-The @code{value} attribute has already been populated with the new
-value and may be used in output. This method must return a string.
+If this method exists, @value{GDBN} will call it when a
+@var{parameter}'s value has been changed via the @code{set} API (for
+example, @kbd{set foo off}). The @code{value} attribute has already
+been populated with the new value and may be used in output. This
+method must return a string. If the returned string is not empty,
+@value{GDBN} will present it to the user.
+
+If this method raises the @code{gdb.GdbError} exception
+(@pxref{Exception Handling}), then @value{GDBN} will print the
+exception's string and the @code{set} command will fail. Note,
+however, that the @code{value} attribute will not be reset in this
+case. So, if your parameter must validate values, it should store the
+old value internally and reset the exposed value, like so:
+
+@smallexample
+class ExampleParam (gdb.Parameter):
+ def __init__ (self, name):
+ super (ExampleParam, self).__init__ (name,
+ gdb.COMMAND_DATA,
+ gdb.PARAM_BOOLEAN)
+ self.value = True
+ self.saved_value = True
+ def validate(self):
+ return False
+ def get_set_string (self):
+ if not self.validate():
+ self.value = self.saved_value
+ raise gdb.GdbError('Failed to validate')
+ self.saved_value = self.value
+@end smallexample
@end defun
@defun Parameter.get_show_string (self, svalue)
The value is an integer. This is like @code{PARAM_INTEGER}, except 0
is interpreted as itself.
+@findex PARAM_ZUINTEGER
+@findex gdb.PARAM_ZUINTEGER
+@item gdb.PARAM_ZUINTEGER
+The value is an unsigned integer. This is like @code{PARAM_INTEGER},
+except 0 is interpreted as itself, and the value cannot be negative.
+
+@findex PARAM_ZUINTEGER_UNLIMITED
+@findex gdb.PARAM_ZUINTEGER_UNLIMITED
+@item gdb.PARAM_ZUINTEGER_UNLIMITED
+The value is a signed integer. This is like @code{PARAM_ZUINTEGER},
+except the special value -1 should be interpreted to mean
+``unlimited''. Other negative values are not allowed.
+
@findex PARAM_ENUM
@findex gdb.PARAM_ENUM
@item gdb.PARAM_ENUM
of an address space.
It consists of all of the objfiles of the program.
@xref{Objfiles In Python}.
-@xref{Inferiors and Programs, program spaces}, for more details
+@xref{Inferiors Connections and Programs, program spaces}, for more details
about program spaces.
The following progspace-related functions are available in the
@findex gdb.current_progspace
@defun gdb.current_progspace ()
This function returns the program space of the currently selected inferior.
-@xref{Inferiors and Programs}.
+@xref{Inferiors Connections and Programs}. This is identical to
+@code{gdb.selected_inferior().progspace} (@pxref{Inferiors In Python}) and is
+included for historical compatibility.
@end defun
@findex gdb.progspaces
objects. @xref{Frame Filter API}, for more information.
@end defvar
+A program space has the following methods:
+
+@findex Progspace.block_for_pc
+@defun Progspace.block_for_pc (pc)
+Return the innermost @code{gdb.Block} containing the given @var{pc}
+value. If the block cannot be found for the @var{pc} value specified,
+the function will return @code{None}.
+@end defun
+
+@findex Progspace.find_pc_line
+@defun Progspace.find_pc_line (pc)
+Return the @code{gdb.Symtab_and_line} object corresponding to the
+@var{pc} value. @xref{Symbol Tables In Python}. If an invalid value
+of @var{pc} is passed as an argument, then the @code{symtab} and
+@code{line} attributes of the returned @code{gdb.Symtab_and_line}
+object will be @code{None} and 0 respectively.
+@end defun
+
+@findex Progspace.is_valid
+@defun Progspace.is_valid ()
+Returns @code{True} if the @code{gdb.Progspace} object is valid,
+@code{False} if not. A @code{gdb.Progspace} object can become invalid
+if the program space file it refers to is not referenced by any
+inferior. All other @code{gdb.Progspace} methods will throw an
+exception if it is invalid at the time the method is called.
+@end defun
+
+@findex Progspace.objfiles
+@defun Progspace.objfiles ()
+Return a sequence of all the objfiles referenced by this program
+space. @xref{Objfiles In Python}.
+@end defun
+
+@findex Progspace.solib_name
+@defun Progspace.solib_name (address)
+Return the name of the shared library holding the given @var{address}
+as a string, or @code{None}.
+@end defun
+
One may add arbitrary attributes to @code{gdb.Progspace} objects
in the usual Python way.
This is useful if, for example, one needs to do some extra record keeping
gdb.events.new_objfile.connect(new_objfile_handler)
end
(gdb) file /tmp/hello
-Reading symbols from /tmp/hello...done.
+Reading symbols from /tmp/hello...
Computing the answer to the ultimate question ...
(gdb) python print gdb.current_progspace().expensive_computation
42
@findex gdb.objfiles
@defun gdb.objfiles ()
-Return a sequence of all the objfiles current known to @value{GDBN}.
-@xref{Objfiles In Python}.
+Return a sequence of objfiles referenced by the current program space.
+@xref{Objfiles In Python}, and @ref{Progspaces In Python}. This is identical
+to @code{gdb.selected_inferior().progspace.objfiles()} and is included for
+historical compatibility.
@end defun
@findex gdb.lookup_objfile
This is supported only on some operating systems, notably those which use
the ELF format for binary files and the @sc{gnu} Binutils. For more details
about this feature, see the description of the @option{--build-id}
-command-line option in @ref{Options, , Command Line Options, ld.info,
+command-line option in @ref{Options, , Command Line Options, ld,
The GNU Linker}.
@end defun
This is supported only on some operating systems, notably those which use
the ELF format for binary files and the @sc{gnu} Binutils. For more details
about this feature, see the description of the @option{--build-id}
-command-line option in @ref{Options, , Command Line Options, ld.info,
+command-line option in @ref{Options, , Command Line Options, ld,
The GNU Linker}.
@end defvar
gdb.events.new_objfile.connect(new_objfile_handler)
end
(gdb) file ./hello
-Reading symbols from ./hello...done.
+Reading symbols from ./hello...
(gdb) python print gdb.objfiles()[0].time_loaded
2014-10-09 11:41:36.770345
@end smallexample
from a different place.
@end defun
+@defun Objfile.lookup_global_symbol (name @r{[}, domain@r{]})
+Search for a global symbol named @var{name} in this objfile. Optionally, the
+search scope can be restricted with the @var{domain} argument.
+The @var{domain} argument must be a domain constant defined in the @code{gdb}
+module and described in @ref{Symbols In Python}. This function is similar to
+@code{gdb.lookup_global_symbol}, except that the search is limited to this
+objfile.
+
+The result is a @code{gdb.Symbol} object or @code{None} if the symbol
+is not found.
+@end defun
+
+@defun Objfile.lookup_static_symbol (name @r{[}, domain@r{]})
+Like @code{Objfile.lookup_global_symbol}, but searches for a global
+symbol with static linkage named @var{name} in this objfile.
+@end defun
+
@node Frames In Python
-@subsubsection Accessing inferior stack frames from Python.
+@subsubsection Accessing inferior stack frames from Python
@cindex frames in python
When the debugged program stops, @value{GDBN} is able to analyze its call
@end defun
@defun Frame.block ()
-Return the frame's code block. @xref{Blocks In Python}.
+Return the frame's code block. @xref{Blocks In Python}. If the frame
+does not have a block -- for example, if there is no debugging
+information for the code in question -- then this will throw an
+exception.
@end defun
@defun Frame.function ()
@xref{Symbol Tables In Python}.
@end defun
+@anchor{gdbpy_frame_read_register}
@defun Frame.read_register (register)
Return the value of @var{register} in this frame. The @var{register}
argument must be a string (e.g., @code{'sp'} or @code{'rax'}).
@end defun
@node Blocks In Python
-@subsubsection Accessing blocks from Python.
+@subsubsection Accessing blocks from Python
@cindex blocks in python
@tindex gdb.Block
should not assume that a specific block object will always contain a
given symbol, since changes in @value{GDBN} features and
infrastructure may cause symbols move across blocks in a symbol
-table.
+table. You can also use Python's @dfn{dictionary syntax} to access
+variables in this block, e.g.:
+
+@smallexample
+symbol = some_block['variable'] # symbol is of type gdb.Symbol
+@end smallexample
The following block-related functions are available in the @code{gdb}
module:
@defun gdb.block_for_pc (pc)
Return the innermost @code{gdb.Block} containing the given @var{pc}
value. If the block cannot be found for the @var{pc} value specified,
-the function will return @code{None}.
+the function will return @code{None}. This is identical to
+@code{gdb.current_progspace().block_for_pc(pc)} and is included for
+historical compatibility.
@end defun
A @code{gdb.Block} object has the following methods:
@end defvar
@defvar Block.end
-The end address of the block. This attribute is not writable.
+One past the last address that appears in the block. This attribute
+is not writable.
@end defvar
@defvar Block.function
@end defvar
@node Symbols In Python
-@subsubsection Python representation of Symbols.
+@subsubsection Python representation of Symbols
@cindex symbols in python
@tindex gdb.Symbol
is not found.
@end defun
+@findex gdb.lookup_static_symbol
+@defun gdb.lookup_static_symbol (name @r{[}, domain@r{]})
+This function searches for a global symbol with static linkage by name.
+The search scope can be restricted to by the domain argument.
+
+@var{name} is the name of the symbol. It must be a string.
+The optional @var{domain} argument restricts the search to the domain type.
+The @var{domain} argument must be a domain constant defined in the @code{gdb}
+module and described later in this chapter.
+
+The result is a @code{gdb.Symbol} object or @code{None} if the symbol
+is not found.
+
+Note that this function will not find function-scoped static variables. To look
+up such variables, iterate over the variables of the function's
+@code{gdb.Block} and check that @code{block.addr_class} is
+@code{gdb.SYMBOL_LOC_STATIC}.
+
+There can be multiple global symbols with static linkage with the same
+name. This function will only return the first matching symbol that
+it finds. Which symbol is found depends on where @value{GDBN} is
+currently stopped, as @value{GDBN} will first search for matching
+symbols in the current object file, and then search all other object
+files. If the application is not yet running then @value{GDBN} will
+search all object files in the order they appear in the debug
+information.
+@end defun
+
+@findex gdb.lookup_static_symbols
+@defun gdb.lookup_static_symbols (name @r{[}, domain@r{]})
+Similar to @code{gdb.lookup_static_symbol}, this function searches for
+global symbols with static linkage by name, and optionally restricted
+by the domain argument. However, this function returns a list of all
+matching symbols found, not just the first one.
+
+@var{name} is the name of the symbol. It must be a string.
+The optional @var{domain} argument restricts the search to the domain type.
+The @var{domain} argument must be a domain constant defined in the @code{gdb}
+module and described later in this chapter.
+
+The result is a list of @code{gdb.Symbol} objects which could be empty
+if no matching symbols were found.
+
+Note that this function will not find function-scoped static variables. To look
+up such variables, iterate over the variables of the function's
+@code{gdb.Block} and check that @code{block.addr_class} is
+@code{gdb.SYMBOL_LOC_STATIC}.
+@end defun
+
A @code{gdb.Symbol} object has the following attributes:
@defvar Symbol.type
@item gdb.SYMBOL_LABEL_DOMAIN
This domain contains names of labels (for gotos).
-@vindex SYMBOL_VARIABLES_DOMAIN
-@item gdb.SYMBOL_VARIABLES_DOMAIN
-This domain holds a subset of the @code{SYMBOLS_VAR_DOMAIN}; it
-contains everything minus functions and types.
-
-@vindex SYMBOL_FUNCTIONS_DOMAIN
-@item gdb.SYMBOL_FUNCTION_DOMAIN
-This domain contains all functions.
+@vindex SYMBOL_MODULE_DOMAIN
+@item gdb.SYMBOL_MODULE_DOMAIN
+This domain contains names of Fortran module types.
-@vindex SYMBOL_TYPES_DOMAIN
-@item gdb.SYMBOL_TYPES_DOMAIN
-This domain contains all types.
+@vindex SYMBOL_COMMON_BLOCK_DOMAIN
+@item gdb.SYMBOL_COMMON_BLOCK_DOMAIN
+This domain contains names of Fortran common blocks.
@end vtable
The available address class categories in @code{gdb.Symbol} are represented
@vindex SYMBOL_LOC_COMPUTED
@item gdb.SYMBOL_LOC_COMPUTED
The value's address is a computed location.
+
+@vindex SYMBOL_LOC_COMPUTED
+@item gdb.SYMBOL_LOC_COMPUTED
+The value's address is a symbol. This is only used for Fortran common
+blocks.
@end vtable
@node Symbol Tables In Python
-@subsubsection Symbol table representation in Python.
+@subsubsection Symbol table representation in Python
@cindex symbol tables in python
@tindex gdb.Symtab
Python code can manipulate breakpoints via the @code{gdb.Breakpoint}
class.
-@defun Breakpoint.__init__ (spec @r{[}, type @r{[}, wp_class @r{[},internal @r{[},temporary@r{]]]]})
-Create a new breakpoint according to @var{spec}, which is a string
-naming the location of the breakpoint, or an expression that defines a
-watchpoint. The contents can be any location recognized by the
-@code{break} command, or in the case of a watchpoint, by the
-@code{watch} command. The optional @var{type} denotes the breakpoint
-to create from the types defined later in this chapter. This argument
-can be either @code{gdb.BP_BREAKPOINT} or @code{gdb.BP_WATCHPOINT}; it
-defaults to @code{gdb.BP_BREAKPOINT}. The optional @var{internal}
-argument allows the breakpoint to become invisible to the user. The
-breakpoint will neither be reported when created, nor will it be
-listed in the output from @code{info breakpoints} (but will be listed
-with the @code{maint info breakpoints} command). The optional
-@var{temporary} argument makes the breakpoint a temporary breakpoint.
-Temporary breakpoints are deleted after they have been hit. Any
-further access to the Python breakpoint after it has been hit will
-result in a runtime error (as that breakpoint has now been
-automatically deleted). The optional @var{wp_class} argument defines
-the class of watchpoint to create, if @var{type} is
-@code{gdb.BP_WATCHPOINT}. If a watchpoint class is not provided, it
-is assumed to be a @code{gdb.WP_WRITE} class.
+A breakpoint can be created using one of the two forms of the
+@code{gdb.Breakpoint} constructor. The first one accepts a string
+like one would pass to the @code{break}
+(@pxref{Set Breaks,,Setting Breakpoints}) and @code{watch}
+(@pxref{Set Watchpoints, , Setting Watchpoints}) commands, and can be used to
+create both breakpoints and watchpoints. The second accepts separate Python
+arguments similar to @ref{Explicit Locations}, and can only be used to create
+breakpoints.
+
+@defun Breakpoint.__init__ (spec @r{[}, type @r{][}, wp_class @r{][}, internal @r{][}, temporary @r{][}, qualified @r{]})
+Create a new breakpoint according to @var{spec}, which is a string naming the
+location of a breakpoint, or an expression that defines a watchpoint. The
+string should describe a location in a format recognized by the @code{break}
+command (@pxref{Set Breaks,,Setting Breakpoints}) or, in the case of a
+watchpoint, by the @code{watch} command
+(@pxref{Set Watchpoints, , Setting Watchpoints}).
+
+The optional @var{type} argument specifies the type of the breakpoint to create,
+as defined below.
+
+The optional @var{wp_class} argument defines the class of watchpoint to create,
+if @var{type} is @code{gdb.BP_WATCHPOINT}. If @var{wp_class} is omitted, it
+defaults to @code{gdb.WP_WRITE}.
+
+The optional @var{internal} argument allows the breakpoint to become invisible
+to the user. The breakpoint will neither be reported when created, nor will it
+be listed in the output from @code{info breakpoints} (but will be listed with
+the @code{maint info breakpoints} command).
+
+The optional @var{temporary} argument makes the breakpoint a temporary
+breakpoint. Temporary breakpoints are deleted after they have been hit. Any
+further access to the Python breakpoint after it has been hit will result in a
+runtime error (as that breakpoint has now been automatically deleted).
+
+The optional @var{qualified} argument is a boolean that allows interpreting
+the function passed in @code{spec} as a fully-qualified name. It is equivalent
+to @code{break}'s @code{-qualified} flag (@pxref{Linespec Locations} and
+@ref{Explicit Locations}).
+
+@end defun
+
+@defun Breakpoint.__init__ (@r{[} source @r{][}, function @r{][}, label @r{][}, line @r{]}, @r{][} internal @r{][}, temporary @r{][}, qualified @r{]})
+This second form of creating a new breakpoint specifies the explicit
+location (@pxref{Explicit Locations}) using keywords. The new breakpoint will
+be created in the specified source file @var{source}, at the specified
+@var{function}, @var{label} and @var{line}.
+
+@var{internal}, @var{temporary} and @var{qualified} have the same usage as
+explained previously.
@end defun
The available types are represented by constants defined in the @code{gdb}
This attribute holds the commands attached to the breakpoint. If
there are commands, this attribute's value is a string holding all the
commands, separated by newlines. If there are no commands, this
-attribute is @code{None}. This attribute is not writable.
+attribute is @code{None}. This attribute is writable.
@end defvar
@node Finish Breakpoints in Python
@end defvar
@node Lazy Strings In Python
-@subsubsection Python representation of lazy strings.
+@subsubsection Python representation of lazy strings
@cindex lazy strings in python
@tindex gdb.LazyString
@defvar LazyString.type
This attribute holds the type that is represented by the lazy string's
-type. For a lazy string this will always be a pointer type. To
+type. For a lazy string this is a pointer or array type. To
resolve this to the lazy string's character type, use the type's
@code{target} method. @xref{Types In Python}. This attribute is not
writable.
@end table
@end defun
+@anchor{gdbpy_architecture_registers}
+@defun Architecture.registers (@r{[} @var{reggroup} @r{]})
+Return a @code{gdb.RegisterDescriptorIterator} (@pxref{Registers In
+Python}) for all of the registers in @var{reggroup}, a string that is
+the name of a register group. If @var{reggroup} is omitted, or is the
+empty string, then the register group @samp{all} is assumed.
+@end defun
+
+@anchor{gdbpy_architecture_reggroups}
+@defun Architecture.register_groups ()
+Return a @code{gdb.RegisterGroupsIterator} (@pxref{Registers In
+Python}) for all of the register groups available for the
+@code{gdb.Architecture}.
+@end defun
+
+@node Registers In Python
+@subsubsection Registers In Python
+@cindex Registers In Python
+
+Python code can request from a @code{gdb.Architecture} information
+about the set of registers available
+(@pxref{gdbpy_architecture_registers,,@code{Architecture.registers}}).
+The register information is returned as a
+@code{gdb.RegisterDescriptorIterator}, which is an iterator that in
+turn returns @code{gdb.RegisterDescriptor} objects.
+
+A @code{gdb.RegisterDescriptor} does not provide the value of a
+register (@pxref{gdbpy_frame_read_register,,@code{Frame.read_register}}
+for reading a register's value), instead the @code{RegisterDescriptor}
+is a way to discover which registers are available for a particular
+architecture.
+
+A @code{gdb.RegisterDescriptor} has the following read-only properties:
+
+@defvar RegisterDescriptor.name
+The name of this register.
+@end defvar
+
+Python code can also request from a @code{gdb.Architecture}
+information about the set of register groups available on a given
+architecture
+(@pxref{gdbpy_architecture_reggroups,,@code{Architecture.register_groups}}).
+
+Every register can be a member of zero or more register groups. Some
+register groups are used internally within @value{GDBN} to control
+things like which registers must be saved when calling into the
+program being debugged (@pxref{Calling,,Calling Program Functions}).
+Other register groups exist to allow users to easily see related sets
+of registers in commands like @code{info registers}
+(@pxref{info_registers_reggroup,,@code{info registers
+@var{reggroup}}}).
+
+The register groups information is returned as a
+@code{gdb.RegisterGroupsIterator}, which is an iterator that in turn
+returns @code{gdb.RegisterGroup} objects.
+
+A @code{gdb.RegisterGroup} object has the following read-only
+properties:
+
+@defvar RegisterGroup.name
+A string that is the name of this register group.
+@end defvar
+
+@node TUI Windows In Python
+@subsubsection Implementing new TUI windows
+@cindex Python TUI Windows
+
+New TUI (@pxref{TUI}) windows can be implemented in Python.
+
+@findex gdb.register_window_type
+@defun gdb.register_window_type (@var{name}, @var{factory})
+Because TUI windows are created and destroyed depending on the layout
+the user chooses, new window types are implemented by registering a
+factory function with @value{GDBN}.
+
+@var{name} is the name of the new window. It's an error to try to
+replace one of the built-in windows, but other window types can be
+replaced.
+
+@var{function} is a factory function that is called to create the TUI
+window. This is called with a single argument of type
+@code{gdb.TuiWindow}, described below. It should return an object
+that implements the TUI window protocol, also described below.
+@end defun
+
+As mentioned above, when a factory function is called, it is passed a
+an object of type @code{gdb.TuiWindow}. This object has these
+methods and attributes:
+
+@defun TuiWindow.is_valid ()
+This method returns @code{True} when this window is valid. When the
+user changes the TUI layout, windows no longer visible in the new
+layout will be destroyed. At this point, the @code{gdb.TuiWindow}
+will no longer be valid, and methods (and attributes) other than
+@code{is_valid} will throw an exception.
+@end defun
+
+@defvar TuiWindow.width
+This attribute holds the width of the window. It is not writable.
+@end defvar
+
+@defvar TuiWindow.height
+This attribute holds the height of the window. It is not writable.
+@end defvar
+
+@defvar TuiWindow.title
+This attribute holds the window's title, a string. This is normally
+displayed above the window. This attribute can be modified.
+@end defvar
+
+@defun TuiWindow.erase ()
+Remove all the contents of the window.
+@end defun
+
+@defun TuiWindow.write (@var{string})
+Write @var{string} to the window. @var{string} can contain ANSI
+terminal escape styling sequences; @value{GDBN} will translate these
+as appropriate for the terminal.
+@end defun
+
+The factory function that you supply should return an object
+conforming to the TUI window protocol. These are the method that can
+be called on this object, which is referred to below as the ``window
+object''. The methods documented below are optional; if the object
+does not implement one of these methods, @value{GDBN} will not attempt
+to call it. Additional new methods may be added to the window
+protocol in the future. @value{GDBN} guarantees that they will begin
+with a lower-case letter, so you can start implementation methods with
+upper-case letters or underscore to avoid any future conflicts.
+
+@defun Window.close ()
+When the TUI window is closed, the @code{gdb.TuiWindow} object will be
+put into an invalid state. At this time, @value{GDBN} will call
+@code{close} method on the window object.
+
+After this method is called, @value{GDBN} will discard any references
+it holds on this window object, and will no longer call methods on
+this object.
+@end defun
+
+@defun Window.render ()
+In some situations, a TUI window can change size. For example, this
+can happen if the user resizes the terminal, or changes the layout.
+When this happens, @value{GDBN} will call the @code{render} method on
+the window object.
+
+If your window is intended to update in response to changes in the
+inferior, you will probably also want to register event listeners and
+send output to the @code{gdb.TuiWindow}.
+@end defun
+
+@defun Window.hscroll (@var{num})
+This is a request to scroll the window horizontally. @var{num} is the
+amount by which to scroll, with negative numbers meaning to scroll
+right. In the TUI model, it is the viewport that moves, not the
+contents. A positive argument should cause the viewport to move
+right, and so the content should appear to move to the left.
+@end defun
+
+@defun Window.vscroll (@var{num})
+This is a request to scroll the window vertically. @var{num} is the
+amount by which to scroll, with negative numbers meaning to scroll
+backward. In the TUI model, it is the viewport that moves, not the
+contents. A positive argument should cause the viewport to move down,
+and so the content should appear to move up.
+@end defun
+
@node Python Auto-loading
@subsection Python Auto-loading
@cindex Python auto-loading
For example:
@smallexample
-substitute_prompt (``frame: \f,
- print arguments: \p@{print frame-arguments@}'')
+substitute_prompt ("frame: \f, args: \p@{print frame-arguments@}")
@end smallexample
@exdent will return the string:
@smallexample
-"frame: main, print arguments: scalars"
+"frame: main, args: scalars"
@end smallexample
@end table
projects / deliverable / binutils-gdb.git / blobdiff