Commit Graph

39 Commits

Author SHA1 Message Date
Omar Sandoval
d4e0771f87 libdrgn: return error from drgn_program_{is_little_endian,bswap,is_64_bit}()
Most places that call these check has_platform and return an error, and
those that don't can live with the extra check.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
2020-08-26 16:56:28 -07:00
Omar Sandoval
971a2d3687 libdrgn/python: make Objects fully immutable
The model has always been that drgn Objects are immutable, but for some
reason I went through the trouble of allowing __init__() to reinitialize
an already initialized Object. Instead, let's fully initialize the
Object in __new__() and get rid of __init__().
2020-05-18 00:07:49 -07:00
Omar Sandoval
ab876f3dbd libdrgn/python: allow specifying Object value positionally
It's annoying to have to do value= when creating objects, especially in
interactive mode. Let's allow passing in the value positionally so that
`Object(prog, "int", value=0)` becomes `Object(prog, "int", 0)`. It's
clear enough that this is creating an int with value 0.
2020-05-18 00:07:49 -07:00
Omar Sandoval
8b264f8823 Update copyright headers to Facebook and add missing headers
drgn was originally my side project, but for awhile now it's also been
my work project. Update the copyright headers to reflect this, and add a
copyright header to various files that were missing it.
2020-05-15 15:13:02 -07:00
Omar Sandoval
0a100064c1 libdrgn: improve and rename DRGN_UNREACHABLE()
DRGN_UNREACHABLE() currently expands to abort(), but assert() provides
more information. If NDEBUG is defined, we can use
__builtin_unreachable() instead.

DRGN_UNREACHABLE() isn't drgn-specific, so this renames it to
UNREACHABLE(). It's also not really related to errors, so this moves it
to internal.h.
2020-05-07 15:16:22 -07:00
Omar Sandoval
ea3cdb43f7 libdrgn/python: optimize Object.__getattribute__()
DrgnObject_getattro() uses PyObject_GenericGetAttr() and catches the
AttributeError raised if the name is not an attribute of the Object
class. If the member is found, we then destroy the AttributeError.
Raising an exception only to destroy it is obviously wasteful. Luckily,
as of Python 3.7, the lower-level _PyObject_GenericGetAttrWithDict() can
suppress the AttributeError; we can raise it ourselves if we need it. In
my microbenchmarks, this makes Object.__getattribute__() at least twice
as fast when the member exists.

This also fixes a drgn_error leak.
2020-04-20 17:45:30 -07:00
Omar Sandoval
79f973007b libdrgn/python: fix reference counting on Object.type_
We need to keep the Program alive for its types to stay valid, not just
the objects the Program has pinned. (I have no idea why I changed this
in commit 565e0343ef ("libdrgn: make symbol index pluggable with
callbacks").)
2020-03-13 16:05:43 -07:00
Omar Sandoval
9de2cc8410 libdrgn/python: make Object.__index__() TypeError message clearer
Currently, we print:

>>> prog.symbol(prog['init_task'])
Traceback (most recent call last):
  File "<console>", line 1, in <module>
TypeError: cannot convert 'struct task_struct' to index

It's not obvious what it means to convert to an index. Instead, let's
use the error message raised by operator.index():

TypeError: 'struct task_struct' object cannot be interpreted as an integer
2020-02-11 09:19:53 -08:00
Serapheim Dimitropoulos
ad82e9623a Introduce OutOfBoundsError
Decouple some of the responsibilities of FaultError to
OutOfBoundsError so consumers can differentiate between
invalid memory accesses and running out of bounds in
drgn Objects which may be based on valid memory address.
2020-02-04 14:59:31 -08:00
Omar Sandoval
1443d17fb4 libdrgn: add DRGN_FORMAT_OBJECT_IMPLICIT_ELEMENTS 2019-12-19 11:43:54 -08:00
Omar Sandoval
db66952b2e libdrgn: add DRGN_FORMAT_OBJECT_IMPLICIT_MEMBERS 2019-12-19 11:43:54 -08:00
Omar Sandoval
c8434e9a9e libdrgn: add DRGN_FORMAT_OBJECT_ELEMENT_INDICES 2019-12-19 11:43:54 -08:00
Omar Sandoval
cfceb491db libdrgn: add DRGN_FORMAT_OBJECT_MEMBER_NAMES 2019-12-19 11:43:54 -08:00
Omar Sandoval
4fad941ec1 libdrgn: add DRGN_FORMAT_OBJECT_{MEMBERS,ELEMENTS}_SAME_LINE 2019-12-19 11:43:54 -08:00
Omar Sandoval
d77b7bd7e3 libdrgn: add DRGN_FORMAT_OBJECT_{TYPE_NAME,MEMBER_TYPE_NAMES,ELEMENT_TYPE_NAMES} 2019-12-19 11:43:54 -08:00
Omar Sandoval
89307c532a libdrgn: add DRGN_FORMAT_OBJECT_CHAR 2019-12-19 11:43:54 -08:00
Omar Sandoval
7cee597fff libdrgn: add DRGN_FORMAT_OBJECT_STRING 2019-12-19 11:43:54 -08:00
Omar Sandoval
5865fa4d16 libdrgn: add DRGN_FORMAT_OBJECT_SYMBOLIZE 2019-12-19 11:43:54 -08:00
Omar Sandoval
f58bc4bf3a libdrgn: add DRGN_FORMAT_OBJECT_DEREFERENCE 2019-12-19 11:43:54 -08:00
Omar Sandoval
5fb02f03fd libdrgn: add flags to drgn_format_object() 2019-12-19 11:43:54 -08:00
Omar Sandoval
cf3a07bdfb libdrgn: python: replace Object.__format__ with Object.format_
We'd like to have more control over how objects are formatted. I
considered defining a custom string format specification syntax, but
that's not easily discoverable. Instead, let's get rid of the current
format specification support and replace it with a normal method.
2019-12-19 11:43:52 -08:00
Omar Sandoval
3b22bd3022 libdrgn: rename pretty_print -> format
In preparation for making drgn_pretty_print_object() more flexible
(i.e., not always "pretty"), rename it to drgn_format_object(). For
consistency, let's rename drgn_pretty_print_type_name(),
drgn_pretty_print_type(), and drgn_pretty_print_stack_trace(), too.
2019-12-16 11:21:12 -08:00
Omar Sandoval
7b518fc2fd libdrgn: support negative array subscripts
This was an oversight, as negative indices are completely valid (and
occasionally useful, like when looking at a stack).
2019-11-29 21:06:37 -08:00
Omar Sandoval
2561226918 libdrgn: python: add signed integer support to index_converter
This is preparation for the next change.
2019-11-29 20:40:40 -08:00
Omar Sandoval
b8b93ae3e6 libdrgn: python: fix deprecation warning in unit tests
Some tests (e.g., tests.test_object.TestSpecialMethods.test_round) are
printing:

  DeprecationWarning: an integer is required (got type float).  Implicit
  conversion to integers using __int__ is deprecated, and may be removed
  in a future version of Python.

See https://bugs.python.org/issue36048. This is coming from calls like:

  Object(prog, 'int', value=1.5)

We actually want the truncating behavior, so explicitly call
PyNumber_Long().
2019-11-22 17:18:55 -08:00
Amlan Nayak
0df2152307 Add basic class type support
This implements the first step at supporting C++: class types. In
particular, this adds a new drgn_type_kind, DRGN_TYPE_CLASS, and support
for parsing DW_TAG_class_type from DWARF. Although classes are not valid
in C, this adds support for pretty printing them, for completeness.
2019-11-18 10:36:40 -08:00
Omar Sandoval
b49f773fe6 libdrgn: python: fix build on Python 3.8
Python 3.8 replaced the unused void *tp_print field with Py_ssize_t
tp_vectorcall_offset, so with -Werror we get "error: initialization of
‘long int’ from ‘void *’ makes integer from pointer without a cast".
Let's just use designated initializers.
2019-11-15 10:41:58 -08:00
Omar Sandoval
c243daed59 Translate find_task() helper (and dependencies) to C
We'd like to be able to look up tasks by PID from libdrgn, but those
helpers are written in Python. Translate them to C and add some thin
bindings so we can use the same implementation from Python.
2019-10-28 13:08:57 -07:00
Omar Sandoval
430732093d libdrgn: python: add converter for byteorder
Rather than open-coding the conversion where we need it, make it a
proper converter function.
2019-10-15 21:21:21 -07:00
Omar Sandoval
55a9700435 libdrgn: python: accept integer-like arguments in more places
There are a few places (e.g., Program.symbol(), Program.read()) where it
makes sense to accept, e.g., a drgn.Object with integer type. Replace
index_arg() with a converter function and use it everywhere that we use
the "K" format for PyArg_Parse*.
2019-10-15 21:10:11 -07:00
Omar Sandoval
690b5fd650 libdrgn: generalize architecture to platform
For stack trace support, we'll need to have some architecture-specific
functionality. drgn's current notion of an architecture doesn't actually
include the instruction set architecture. This change expands it to a
"platform", which includes the ISA as well as the existing flags.
2019-08-02 00:11:56 -07:00
Omar Sandoval
b01d1a943f libdrgn: python: make set_drgn_error() return void *
It still always returns NULL, but now we can directly return from
functions returning some PyObject subtype.
2019-07-28 00:58:36 -07:00
Omar Sandoval
baba1ff3f0 libdrgn: make program components pluggable
Currently, programs can be created for three main use-cases: core dumps,
the running kernel, and a running process. However, internally, the
program memory, types, and symbols are pluggable. Expose that as a
callback API, which makes it possible to use drgn in much more creative
ways.
2019-05-10 12:41:07 -07:00
Omar Sandoval
565e0343ef libdrgn: make symbol index pluggable with callbacks
The last piece of making the major program components pluggable.
2019-05-06 14:55:34 -07:00
Omar Sandoval
043cddf6d8 libdrgn: move member cache to type index
It makes more sense here than in struct drgn_program.
2019-05-06 14:55:34 -07:00
Omar Sandoval
1b4aee1a55 libdrgn/python: add Program.pointer_type() 2019-04-11 23:35:10 -07:00
Omar Sandoval
393a1f3149 Document with Sphinx
drgn has pretty thorough in-program documentation, but it doesn't have a
nice overview or introduction to the basic concepts. This commit adds
that using Sphinx. In order to avoid documenting everything in two
places, the libdrgn bindings have their docstrings generated from the
API documentation. The alternative would be to use Sphinx's autodoc
extension, but that's not as flexible and would also require building
the extension to build the docs. The documentation for the helpers is
generated using autodoc and a small custom extension.
2019-04-11 12:48:15 -07:00
Omar Sandoval
321e2c210e libdrgn/python: format pointers in hex for Object.__repr__() 2019-04-05 10:36:54 -07:00
Omar Sandoval
687ea74ff2 Build Python bindings with automake
I went back and forth on using setuptools or autotools for the Python
extension, but I eventually settled on using only setuptools after
fighting to get the two to integrate well. However, setuptools is kind
of crappy; for one, it rebuilds every source file when rebuilding the
extension, which is really annoying for development. automake is a
better designed build system overall, so let's use that for the
extension. We override the build_ext command to build using autotools
and copy things where setuptools expects them.
2019-04-03 17:00:53 -07:00