-@c Copyright (C) 2008-2014 Free Software Foundation, Inc.
+@c Copyright (C) 2008-2019 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
* Frame Filter API:: Filtering Frames.
* Frame Decorator API:: Decorating Frames.
* Writing a Frame Filter:: Writing a Frame Filter.
+* Unwinding Frames in Python:: Writing frame unwinder.
* Xmethods In Python:: Adding and replacing methods of C++ classes.
* Xmethod API:: Xmethod types.
* Writing an Xmethod:: Writing an xmethod.
* Inferiors In Python:: Python representation of inferiors (processes)
* Events In Python:: Listening for events from @value{GDBN}.
* Threads In Python:: Accessing inferior threads from Python.
+* Recordings In Python:: Accessing recordings from Python.
* Commands In Python:: Implementing new commands in Python.
* Parameters In Python:: Adding new @value{GDBN} parameters.
* Functions In Python:: Writing new convenience functions.
@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}).
@findex gdb.breakpoints
@defun gdb.breakpoints ()
Return a sequence holding all of @value{GDBN}'s breakpoints.
-@xref{Breakpoints In Python}, for more information.
+@xref{Breakpoints In Python}, for more information. In @value{GDBN}
+version 7.11 and earlier, this function returned @code{None} if there
+were no breakpoints. This peculiarity was subsequently fixed, and now
+@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
@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
corresponding to @code{val}.
@end defun
+@defun Value.reference_value ()
+Return a @code{gdb.Value} object which is a reference to the value
+encapsulated by this instance.
+@end defun
+
+@defun Value.const_value ()
+Return a @code{gdb.Value} object which is a @code{const} version of the
+value encapsulated by this instance.
+@end defun
+
@defun Value.dynamic_cast (type)
Like @code{Value.cast}, but works as if the C@t{++} @code{dynamic_cast}
operator were used. Consult a C@t{++} reference for details.
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.
@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 ()
@table @code
@item bitpos
This attribute is not available for @code{enum} or @code{static}
-(as in C@t{++} or Java) fields. The value is the position, counting
+(as in C@t{++}) fields. The value is the position, counting
in bits, from the start of the containing type.
@item enumval
Otherwise, it is searched for globally.
@end defun
+@defun Type.optimized_out ()
+Return @code{gdb.Value} instance of this type whose value is optimized
+out. This allows a frame decorator to indicate that the value of an
+argument or a local variable is not known.
+@end defun
Each type has a code, which indicates what category this type falls
into. The available type categories are represented by constants
@vindex TYPE_CODE_METHOD
@item gdb.TYPE_CODE_METHOD
-A method type, as found in C@t{++} or Java.
+A method type, as found in C@t{++}.
@vindex TYPE_CODE_METHODPTR
@item gdb.TYPE_CODE_METHODPTR
@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
marker in the inlined frame, and also show the hierarchical
relationship.
+@node Unwinding Frames in Python
+@subsubsection Unwinding Frames in Python
+@cindex unwinding frames in Python
+
+In @value{GDBN} terminology ``unwinding'' is the process of finding
+the previous frame (that is, caller's) from the current one. An
+unwinder has three methods. The first one checks if it can handle
+given frame (``sniff'' it). For the frames it can sniff an unwinder
+provides two additional methods: it can return frame's ID, and it can
+fetch registers from the previous frame. A running @value{GDBN}
+mantains a list of the unwinders and calls each unwinder's sniffer in
+turn until it finds the one that recognizes the current frame. There
+is an API to register an unwinder.
+
+The unwinders that come with @value{GDBN} handle standard frames.
+However, mixed language applications (for example, an application
+running Java Virtual Machine) sometimes use frame layouts that cannot
+be handled by the @value{GDBN} unwinders. You can write Python code
+that can handle such custom frames.
+
+You implement a frame unwinder in Python as a class with which has two
+attributes, @code{name} and @code{enabled}, with obvious meanings, and
+a single method @code{__call__}, which examines a given frame and
+returns an object (an instance of @code{gdb.UnwindInfo class)}
+describing it. If an unwinder does not recognize a frame, it should
+return @code{None}. The code in @value{GDBN} that enables writing
+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{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. 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}
+instance to be returned to @value{GDBN}:
+
+@defun PendingFrame.create_unwind_info (frame_id)
+Returns a new @code{gdb.UnwindInfo} instance identified by given
+@var{frame_id}. The argument is used to build @value{GDBN}'s frame ID
+using one of functions provided by @value{GDBN}. @var{frame_id}'s attributes
+determine which function will be used, as follows:
+
+@table @code
+@item sp, 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 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
+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
+
+Each attribute value should be an instance of @code{gdb.Value}.
+
+@end defun
+
+@subheading Unwinder Output: UnwindInfo
+
+Use @code{PendingFrame.create_unwind_info} method described above to
+create a @code{gdb.UnwindInfo} instance. Use the following method to
+specify caller registers that have been saved in this frame:
+
+@defun gdb.UnwindInfo.add_saved_register (reg, value)
+@var{reg} identifies the register. It can be a number or a name, just
+as for the @code{PendingFrame.read_register} method above.
+@var{value} is a register value (a @code{gdb.Value} object).
+@end defun
+
+@subheading Unwinder Skeleton Code
+
+@value{GDBN} comes with the module containing the base @code{Unwinder}
+class. Derive your unwinder class from it and structure the code as
+follows:
+
+@smallexample
+from gdb.unwinders import Unwinder
+
+class FrameId(object):
+ def __init__(self, sp, pc):
+ self.sp = sp
+ self.pc = pc
+
+
+class MyUnwinder(Unwinder):
+ def __init__(....):
+ super(MyUnwinder, self).__init___(<expects unwinder name argument>)
+
+ def __call__(pending_frame):
+ if not <we recognize frame>:
+ return None
+ # Create UnwindInfo. Usually the frame is identified by the stack
+ # pointer and the program counter.
+ sp = pending_frame.read_register(<SP number>)
+ pc = pending_frame.read_register(<PC number>)
+ unwind_info = pending_frame.create_unwind_info(FrameId(sp, pc))
+
+ # Find the values of the registers in the caller's frame and
+ # save them in the result:
+ unwind_info.add_saved_register(<register>, <value>)
+ ....
+
+ # Return the result:
+ return unwind_info
+
+@end smallexample
+
+@subheading Registering a Unwinder
+
+An object file, a program space, and the @value{GDBN} proper can have
+unwinders registered with it.
+
+The @code{gdb.unwinders} module provides the function to register a
+unwinder:
+
+@defun gdb.unwinder.register_unwinder (locus, unwinder, replace=False)
+@var{locus} is specifies an object file or a program space to which
+@var{unwinder} is added. Passing @code{None} or @code{gdb} adds
+@var{unwinder} to the @value{GDBN}'s global unwinder list. The newly
+added @var{unwinder} will be called before any other unwinder from the
+same locus. Two unwinders in the same locus cannot have the same
+name. An attempt to add a unwinder with already existing name raises
+an exception unless @var{replace} is @code{True}, in which case the
+old unwinder is deleted.
+@end defun
+
+@subheading Unwinder Precedence
+
+@value{GDBN} first calls the unwinders from all the object files in no
+particular order, then the unwinders from the current program space,
+and finally the unwinders from @value{GDBN}.
+
@node Xmethods In Python
@subsubsection Xmethods In Python
@cindex xmethods in Python
method, then the xmethod worker is treated as a replacement for
the C@t{++} method. @value{GDBN} uses the overall winner to invoke the
method. If the winning xmethod worker is the overall winner, then
-the corresponding xmethod is invoked via the @code{invoke} method
+the corresponding xmethod is invoked via the @code{__call__} method
of the worker object.
If one wants to implement an xmethod as a replacement for an
@code{gdb.Type} object corresponding to it can be returned.
@end defun
+@defun XMethodWorker.get_result_type (self, *args)
+This method returns a @code{gdb.Type} object representing the type
+of the result of invoking this xmethod.
+The @var{args} argument is the same tuple of arguments that would be
+passed to the @code{__call__} method of this worker.
+@end defun
+
@defun XMethodWorker.__call__ (self, *args)
This is the method which does the @emph{work} of the xmethod. The
@var{args} arguments is the tuple of arguments to the xmethod. Each
class MyClassWorker_geta(gdb.xmethod.XMethodWorker):
def get_arg_types(self):
return None
+
+ def get_result_type(self, obj):
+ return gdb.lookup_type('int')
def __call__(self, obj):
return obj['a_']
class MyClassWorker_plus(gdb.xmethod.XMethodWorker):
def get_arg_types(self):
return gdb.lookup_type('MyClass')
+
+ def get_result_type(self, obj):
+ return gdb.lookup_type('int')
def __call__(self, obj, other):
return obj['a_'] + other['a_']
class MyTemplateWorker_footprint(gdb.xmethod.XMethodWorker):
def __init__(self, class_type):
self.class_type = class_type
-
+
def get_arg_types(self):
return None
-
+
+ def get_result_type(self):
+ return gdb.lookup_type('int')
+
def __call__(self, obj):
return (self.class_type.sizeof +
obj['dsize_'] *
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} bytes of memory from the inferior, starting at
+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
@var{address}. The @var{buffer} parameter must be a Python object
which supports the buffer protocol, i.e., a string, an array or the
object returned from @code{Inferior.read_memory}. If given, @var{length}
-determines the number of bytes from @var{buffer} to be written.
+determines the number of addressable memory units from @var{buffer} to be
+written.
@end defun
@findex gdb.search_memory
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
@value{GDBN} detaches from the inferior.) If the exit code is unavailable,
the attribute does not exist.
@end defvar
-@defvar ExitedEvent inferior
+@defvar ExitedEvent.inferior
A reference to the inferior which triggered the @code{exited} event.
@end defvar
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
Denotes which register was modified.
@end defvar
+@item events.breakpoint_created
+This is emitted when a new breakpoint has been created. The argument
+that is passed is the new @code{gdb.Breakpoint} object.
+
+@item events.breakpoint_modified
+This is emitted when a breakpoint has been modified in some way. The
+argument that is passed is the new @code{gdb.Breakpoint} object.
+
+@item events.breakpoint_deleted
+This is emitted when a breakpoint has been deleted. The argument that
+is passed is the @code{gdb.Breakpoint} object. When this event is
+emitted, the @code{gdb.Breakpoint} object will already be in its
+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
@end defvar
@defvar InferiorThread.num
-ID of the thread, as assigned by GDB.
+The per-inferior number of the thread, as assigned by GDB.
+@end defvar
+
+@defvar InferiorThread.global_num
+The global ID of the thread, as assigned by GDB. You can use this to
+make Python breakpoints thread-specific, for example
+(@pxref{python_breakpoint_thread,,The Breakpoint.thread attribute}).
@end defvar
@defvar InferiorThread.ptid
does not use that identifier.
@end defvar
+@defvar InferiorThread.inferior
+The inferior this thread belongs to. This attribute is represented as
+a @code{gdb.Inferior} object. This attribute is not writable.
+@end defvar
+
A @code{gdb.InferiorThread} object has the following methods:
@defun InferiorThread.is_valid ()
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
+
+The following recordings-related functions
+(@pxref{Process Record and Replay}) are available in the @code{gdb}
+module:
+
+@defun gdb.start_recording (@r{[}method@r{]}, @r{[}format@r{]})
+Start a recording using the given @var{method} and @var{format}. If
+no @var{format} is given, the default format for the recording method
+is used. If no @var{method} is given, the default method will be used.
+Returns a @code{gdb.Record} object on success. Throw an exception on
+failure.
+
+The following strings can be passed as @var{method}:
+
+@itemize @bullet
+@item
+@code{"full"}
+@item
+@code{"btrace"}: Possible values for @var{format}: @code{"pt"},
+@code{"bts"} or leave out for default format.
+@end itemize
+@end defun
+
+@defun gdb.current_recording ()
+Access a currently running recording. Return a @code{gdb.Record}
+object on success. Return @code{None} if no recording is currently
+active.
+@end defun
+
+@defun gdb.stop_recording ()
+Stop the current recording. Throw an exception if no recording is
+currently active. All record objects become invalid after this call.
+@end defun
+
+A @code{gdb.Record} object has the following attributes:
+
+@defvar Record.method
+A string with the current recording method, e.g.@: @code{full} or
+@code{btrace}.
+@end defvar
+
+@defvar Record.format
+A string with the current recording format, e.g.@: @code{bt}, @code{pts} or
+@code{None}.
+@end defvar
+
+@defvar Record.begin
+A method specific instruction object representing the first instruction
+in this recording.
+@end defvar
+
+@defvar Record.end
+A method specific instruction object representing the current
+instruction, that is not actually part of the recording.
+@end defvar
+
+@defvar Record.replay_position
+The instruction representing the current replay position. If there is
+no replay active, this will be @code{None}.
+@end defvar
+
+@defvar Record.instruction_history
+A list with all recorded instructions.
+@end defvar
+
+@defvar Record.function_call_history
+A list with all recorded function call segments.
+@end defvar
+
+A @code{gdb.Record} object has the following methods:
+
+@defun Record.goto (instruction)
+Move the replay position to the given @var{instruction}.
+@end defun
+
+The common @code{gdb.Instruction} class that recording method specific
+instruction objects inherit from, has the following attributes:
+
+@defvar Instruction.pc
+An integer representing this instruction's address.
+@end defvar
+
+@defvar Instruction.data
+A buffer with the raw instruction data. In Python 3, the return value is a
+@code{memoryview} object.
+@end defvar
+
+@defvar Instruction.decoded
+A human readable string with the disassembled instruction.
+@end defvar
+
+@defvar Instruction.size
+The size of the instruction in bytes.
+@end defvar
+
+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 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 RecordInstruction.is_speculative
+A boolean indicating whether the instruction was executed speculatively.
+@end defvar
+
+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 RecordGap.error_code
+A numerical representation of the reason for the gap. The value is specific to
+the current recording method.
+@end defvar
+
+@defvar RecordGap.error_string
+A human readable string with the reason for the gap.
+@end defvar
+
+A @code{gdb.RecordFunctionSegment} object has the following attributes:
+
+@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 RecordFunctionSegment.symbol
+A @code{gdb.Symbol} object representing the associated symbol. May be
+@code{None} if no debug information is available.
+@end defvar
+
+@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 RecordFunctionSegment.instructions
+A list of @code{gdb.RecordInstruction} or @code{gdb.RecordGap} objects
+associated with this function call.
+@end defvar
+
+@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 RecordFunctionSegment.prev
+A @code{gdb.RecordFunctionSegment} object representing the previous
+segment of this function call. May be @code{None}.
+@end defvar
+
+@defvar RecordFunctionSegment.next
+A @code{gdb.RecordFunctionSegment} object representing the next segment of
+this function call. May be @code{None}.
+@end defvar
+
+The following example demonstrates the usage of these objects and
+functions to create a function that will rewind a record to the last
+time a function in a different file was executed. This would typically
+be used to track the execution of user provided callback functions in a
+library which typically are not visible in a back trace.
+
+@smallexample
+def bringback ():
+ rec = gdb.current_recording ()
+ if not rec:
+ return
+
+ insn = rec.instruction_history
+ if len (insn) == 0:
+ return
+
+ try:
+ position = insn.index (rec.replay_position)
+ except:
+ position = -1
+ try:
+ filename = insn[position].sal.symtab.fullname ()
+ except:
+ filename = None
+
+ for i in reversed (insn[:position]):
+ try:
+ current = i.sal.symtab.fullname ()
+ except:
+ current = None
+
+ if filename == current:
+ continue
+
+ rec.goto (i)
+ return
+@end smallexample
+
+Another possible application is to write a function that counts the
+number of code executions in a given line range. This line range can
+contain parts of functions or span across several functions and is not
+limited to be contiguous.
+
+@smallexample
+def countrange (filename, linerange):
+ count = 0
+
+ def filter_only (file_name):
+ for call in gdb.current_recording ().function_call_history:
+ try:
+ if file_name in call.symbol.symtab.fullname ():
+ yield call
+ except:
+ pass
+
+ for c in filter_only (filename):
+ for i in c.instructions:
+ try:
+ if i.sal.line in linerange:
+ count += 1
+ break;
+ except:
+ pass
+
+ return count
+@end smallexample
+
@node Commands In Python
@subsubsection Commands In Python
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
@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 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
@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
class.
@defvar Objfile.filename
-The file name of the objfile as a string.
+The file name of the objfile as a string, with symbolic links resolved.
+
+The value is @code{None} if the objfile is no longer valid.
+See the @code{gdb.Objfile.is_valid} method, described below.
+@end defvar
+
+@defvar Objfile.username
+The file name of the objfile as specified by the user as a string.
+
+The value is @code{None} if the objfile is no longer valid.
+See the @code{gdb.Objfile.is_valid} method, described below.
@end defvar
@defvar Objfile.owner
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
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
@code{unwind_stop_reason} method further down in this section).
@end defun
+@findex gdb.invalidate_cached_frames
+@defun gdb.invalidate_cached_frames
+@value{GDBN} internally keeps a cache of the frames that have been
+unwound. This function invalidates this cache.
+
+This function should not generally be called by ordinary Python code.
+It is documented for the sake of completeness.
+@end defun
+
A @code{gdb.Frame} object has the following methods:
@defun Frame.is_valid ()
@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 ()
@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}
+module:
+
+@vtable @code
+@vindex BP_BREAKPOINT
+@item gdb.BP_BREAKPOINT
+Normal code breakpoint.
+
+@vindex BP_WATCHPOINT
+@item gdb.BP_WATCHPOINT
+Watchpoint breakpoint.
+
+@vindex BP_HARDWARE_WATCHPOINT
+@item gdb.BP_HARDWARE_WATCHPOINT
+Hardware assisted watchpoint.
+
+@vindex BP_READ_WATCHPOINT
+@item gdb.BP_READ_WATCHPOINT
+Hardware assisted read watchpoint.
+
+@vindex BP_ACCESS_WATCHPOINT
+@item gdb.BP_ACCESS_WATCHPOINT
+Hardware assisted access watchpoint.
+@end vtable
+
+The available watchpoint types represented by constants are defined in the
+@code{gdb} module:
+
+@vtable @code
+@vindex WP_READ
+@item gdb.WP_READ
+Read only watchpoint.
+
+@vindex WP_WRITE
+@item gdb.WP_WRITE
+Write only watchpoint.
+
+@vindex WP_ACCESS
+@item gdb.WP_ACCESS
+Read/Write watchpoint.
+@end vtable
+
@defun Breakpoint.stop (self)
The @code{gdb.Breakpoint} class can be sub-classed and, in
particular, you may choose to implement the @code{stop} method.
@end smallexample
@end defun
-The available watchpoint types represented by constants are defined in the
-@code{gdb} module:
-
-@vtable @code
-@vindex WP_READ
-@item gdb.WP_READ
-Read only watchpoint.
-
-@vindex WP_WRITE
-@item gdb.WP_WRITE
-Write only watchpoint.
-
-@vindex WP_ACCESS
-@item gdb.WP_ACCESS
-Read/Write watchpoint.
-@end vtable
-
@defun Breakpoint.is_valid ()
Return @code{True} if this @code{Breakpoint} object is valid,
@code{False} otherwise. A @code{Breakpoint} object can become invalid
@code{silent} attribute.
@end defvar
+@defvar Breakpoint.pending
+This attribute is @code{True} if the breakpoint is pending, and
+@code{False} otherwise. @xref{Set Breaks}. This attribute is
+read-only.
+@end defvar
+
+@anchor{python_breakpoint_thread}
@defvar Breakpoint.thread
-If the breakpoint is thread-specific, this attribute holds the thread
-id. If the breakpoint is not thread-specific, this attribute is
-@code{None}. This attribute is writable.
+If the breakpoint is thread-specific, this attribute holds the
+thread's global id. If the breakpoint is not thread-specific, this
+attribute is @code{None}. This attribute is writable.
@end defvar
@defvar Breakpoint.task
writable.
@end defvar
-The available types are represented by constants defined in the @code{gdb}
-module:
-
-@vtable @code
-@vindex BP_BREAKPOINT
-@item gdb.BP_BREAKPOINT
-Normal code breakpoint.
-
-@vindex BP_WATCHPOINT
-@item gdb.BP_WATCHPOINT
-Watchpoint breakpoint.
-
-@vindex BP_HARDWARE_WATCHPOINT
-@item gdb.BP_HARDWARE_WATCHPOINT
-Hardware assisted watchpoint.
-
-@vindex BP_READ_WATCHPOINT
-@item gdb.BP_READ_WATCHPOINT
-Hardware assisted read watchpoint.
-
-@vindex BP_ACCESS_WATCHPOINT
-@item gdb.BP_ACCESS_WATCHPOINT
-Hardware assisted access watchpoint.
-@end vtable
-
@defvar Breakpoint.hit_count
This attribute holds the hit count for the breakpoint, an integer.
This attribute is writable, but currently it can only be set to zero.
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.
Print the list of all Python scripts that @value{GDBN} auto-loaded.
Also printed is the list of Python scripts that were mentioned in
-the @code{.debug_gdb_scripts} section and were not found
-(@pxref{dotdebug_gdb_scripts section}).
+the @code{.debug_gdb_scripts} section and were either not found
+(@pxref{dotdebug_gdb_scripts section}) or were not auto-loaded due to
+@code{auto-load safe-path} rejection (@pxref{Auto-loading}).
This is useful because their names are not printed when @value{GDBN}
tries to load them and fails. There may be many of them, and printing
an error message for each one is problematic.
@end smallexample
@end table
-When reading an auto-loaded file, @value{GDBN} sets the
+When reading an auto-loaded file or script, @value{GDBN} sets the
@dfn{current objfile}. This is available via the @code{gdb.current_objfile}
function (@pxref{Objfiles In Python}). This can be useful for
registering objfile-specific pretty-printers and frame-filters.
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
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