-@c Copyright (C) 2008-2019 Free Software Foundation, Inc.
+@c Copyright (C) 2008--2021 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
@smallexample
(@value{GDBP}) python
-Type python script
-End with a line saying just "end".
>print 23
>end
23
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 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
should be expanded, @code{False} if they shouldn't (see @code{set print
union} in @ref{Print Settings}).
+@item address
+@code{True} if the string representation of a pointer should include the
+address, @code{False} if it shouldn't (see @code{set print address} 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
the @emph{declared} type should be used. (See @code{set print object} in
@ref{Print Settings}).
-@item static_fields
+@item static_members
@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}).
@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
printed for this frame. This iterable must contain objects that
implement two methods, described here.
-This object must implement a @code{argument} method which takes a
+This object must implement a @code{symbol} method which takes a
single @code{self} parameter and must return a @code{gdb.Symbol}
(@pxref{Symbols In Python}), or a Python string. The object must also
implement a @code{value} method which takes a single @code{self}
@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.
+frame as a @code{gdb.Value} object. For a description of the
+acceptable values of @var{reg} see
+@ref{gdbpy_frame_read_register,,Frame.read_register}. 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.
@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
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{reg} identifies the register, for a description of the acceptable
+values see @ref{gdbpy_frame_read_register,,Frame.read_register}.
@var{value} is a register value (a @code{gdb.Value} object).
@end defun
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.
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
@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
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}. This is identical to
+@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
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
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
@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'}).
-Returns a @code{Gdb.Value} object. Throws an exception if @var{register}
-does not exist.
+Return the value of @var{register} in this frame. Returns a
+@code{Gdb.Value} object. Throws an exception if @var{register} does
+not exist. The @var{register} argument must be one of the following:
+@enumerate
+@item
+A string that is the name of a valid register (e.g., @code{'sp'} or
+@code{'rax'}).
+@item
+A @code{gdb.RegisterDescriptor} object (@pxref{Registers In Python}).
+@item
+A @value{GDBN} internal, platform specific number. Using these
+numbers is supported for historic reasons, but is not recommended as
+future changes to @value{GDBN} could change the mapping between
+numbers and the registers they represent, breaking any Python code
+that uses the platform-specific numbers. The numbers are usually
+found in the corresponding @file{@var{platform}-tdep.h} file in the
+@value{GDBN} source tree.
+@end enumerate
+Using a string to access registers will be slightly slower than the
+other two methods as @value{GDBN} must look up the mapping between
+name and internal register number. If performance is critical
+consider looking up and caching a @code{gdb.RegisterDescriptor}
+object.
@end defun
@defun Frame.read_var (variable @r{[}, block@r{]})
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:
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.BP_BREAKPOINT
Normal code breakpoint.
+@vindex BP_HARDWARE_BREAKPOINT
+@item gdb.BP_HARDWARE_BREAKPOINT
+Hardware assisted code breakpoint.
+
@vindex BP_WATCHPOINT
@item gdb.BP_WATCHPOINT
Watchpoint breakpoint.
@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
+
+It is also possible to lookup a register descriptor based on its name
+using the following @code{gdb.RegisterDescriptorIterator} function:
+
+@defun RegisterDescriptorIterator.find (@var{name})
+Takes @var{name} as an argument, which must be a string, and returns a
+@code{gdb.RegisterDescriptor} for the register with that name, or
+@code{None} if there is no register with that name.
+@end defun
+
+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
+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