We've nominally supported complex types since commit 75c3679147
("Rewrite drgn core in C"), but parsing them from DWARF has been
incorrect from the start (they don't have a DW_AT_type attribute like we
assume), and we never implemented proper support for complex objects.
Drop the partial implementation; we can bring it back (properly) if
someone requests it.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Add struct drgn_type_template_parameter to libdrgn, the corresponding
TypeTemplateParameter to the Python bindings, and support for parsing
them from DWARF.
With this, support for templates is almost, but not quite, complete. The
main wart is that DW_TAG_name of compound types includes the template
parameters, so the type tag includes it as well. We should remove that
from the tag and instead have the type formatting code add it only when
getting the full type name.
Based on a patch from Jay Kamat.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
I was going to add an Object.available_ attribute, but that made me
realize that the naming is somewhat ambiguous, as a reference object
with an invalid address might also be considered "unavailable" by users.
Use the name "absent" instead, which is more clear: the object isn't
there at all.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
offsetof() can almost be implemented with Type.member(name).offset, but
that doesn't parse member designators. Add an offsetof() function that
does (and add drgn_type_offsetof() in libdrgn).
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Having the signature in the class line is awkward, especially when
__init__() is overloaded. Instead, document __init__() separately, but
refer to it by the name of the class. There might still be a better way
to represent this, but this is at least better than before.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Python 3.9 stopped emitting ast.Index nodes, which broke skipping
parentheses around tuples when they're used as subscripts (e.g., for
generic type annotations). Fix it by removing ast.Index nodes in the
pretransformation step on old versions and then handling the new layout
where the ast.Tuple node is directly in ast.Subscript.slice. While we're
here, make sure that we don't skip the parentheses for an empty tuple in
a subscript.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
There are some situations where we can find an object but can't
determine its value, like local variables that have been optimized out,
inlined functions without a concrete instance, and pure virtual methods.
It's still useful to get some information from these objects, namely
their types. Let's add the concept of an "unavailable" object, which is
an object with a known type but unknown value/address.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
We get the version of drgn with pkg_resources.get_distribution() in two
places: setup.py (when using an sdist) and the CLI. The former causes
problems because in some cases, pip doesn't find the drgn distribution
that's currently being built. The latter adds significant latency to
startup. On my laptop, just importing pkg_resources takes 130 ms. We can
solve both of these problems by generating a file containing the version
instead.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
We use /proc/modules and /sys/module to find loaded kernel modules for
the running kernel instead of walking the module list in the core dump
as an optimization. To make it easier to test the core dump path, add an
environment variable to disable the optimization.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Black was recently changed to treat a trailing comma as an indicator to
put each item/argument on its own line. We have a bunch of places where
something previously had to be split into multiple lines, then was
edited to fit on one line, but Black kept the trailing comma. Now this
update wants to unnecessarily split it back up. For now, let's get rid
of these commas. Hopefully in the future Black has a way to opt out of
this.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
I originally envisioned types as dumb descriptors. This mostly works for
C because in C, types are fairly simple. However, even then the
drgn_program_member_info() API is awkward. You should be able to look up
a member directly from a type, but we need the program for caching
purposes. This has also held me back from adding offsetof() or
has_member() APIs.
Things get even messier with C++. C++ template parameters can be objects
(e.g., template <int N>). Such parameters would best be represented by a
drgn object, which we need a drgn program for. Static members are a
similar case.
So, let's reimagine types as being owned by a program. This has a few
parts:
1. In libdrgn, simple types are now created by factory functions,
drgn_foo_type_create().
2. To handle their variable length fields, compound types, enum types,
and function types are constructed with a "builder" API.
3. Simple types are deduplicated.
4. The Python type factory functions are replaced by methods of the
Program class.
5. While we're changing the API, the parameters to pointer_type() and
array_type() are reordered to be more logical (and to allow
pointer_type() to take a default size of None for the program's
default pointer size).
6. Likewise, the type factory methods take qualifiers as a keyword
argument only.
A big part of this change is updating the tests and splitting up large
test cases into smaller ones in a few places.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
One of the blockers for adding type annotations to helpers is that some
helpers need to be overloaded, but drgndoc doesn't support that. This
adds support. Each function now tracks all of its overloaded signature,
each of which may be documented separately. The formatted output (for
functions/methods and classes with __init__()) combines all of the
documented overloads.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
We can get rid of the :include: and :exclude: options by deciding solely
based on whether a node has a docstring. Empty docstrings can be used to
indicate nodes that should be included with no additional content. The
__init__() method must now also have a docstring in order to be
documented. Additionally, the directives are now fully formatted by the
Formatter rather than being split between the Formatter and
DrgnDocDirective.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
The helpers implemented in C have Python wrappers only for the purpose
of documentation. This is because drgndoc ignores all imports when
recursively documenting attributes. However, mypy uses the convention
that aliased imports (i.e., import ... as ... or from ... import ... as
...) are considered re-exported, so we can follow that convention and
include aliased imports. (mypy also considered attributes in __all__ as
re-exported, so we should probably follow that in the future, too, but
for now aliased imports are enough). This lets us get rid of the Python
wrappers.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Rather than duplicating Union[str, bytes, os.PathLike] everywhere, add
an alias. Also make it explicitly os.PathLike[str] or os.PathLike[bytes]
to get rid of some mypy --strict errors.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Lots if interfaces in drgn transparently turn an integer Object into an
int by using __index__(), so add an IntegerLike protocol for this and
use it everywhere applicable.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
The __init_subclass__ and __class_getitem__ methods are always class
methods even if not decorated as such, so format them accordingly.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
drgn.h is generated from drgn.h.in since commit d60c6a1d68 ("libdrgn:
add register information to platform").
Signed-off-by: Omar Sandoval <osandov@osandov.com>
This documents best practices for contributing to drgn. We now require a
DCO sign-off.
Also clean up some related areas in the documentation.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
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.
Now that we can walk page tables, we can use it in a memory reader that
reads kernel memory via the kernel page table. This means that we don't
need libkdumpfile for ELF vmcores anymore (although I'll keep the
functionality around until this code has been validated more).
parse_package() visits submodules in whatever order they're returned by
the filesystem, which is arbitrary. Let's sort them so we always visit
them in the same order.
String annotations (i.e., forward references) need to be parsed into an
ast node. Do it as a transformation step immediately after parsing the
source. We can also squash the constant node transformation into this
one.
I've been wanting to add type hints for the _drgn C extension for
awhile. The main blocker was that there is a large overlap between the
documentation (in docs/api_reference.rst) and the stub file, and I
really didn't want to duplicate the information. Therefore, it was a
requirement that the the documentation could be generated from the stub
file, or vice versa. Unfortunately, none of the existing tools that I
could find supported this very well. So, I bit the bullet and wrote my
own Sphinx extension that uses the stub file as the source of truth (and
subsumes my old autopackage extension and gen_docstrings script).
The stub file is probably incomplete/inaccurate in places, but this
should be a good starting point to improve on.
Closes#22.
This continues the conversion from the last commit. Members and
parameters are basically the same, so we can do them together. Unlike
enumerators, these don't make sense to unpack or access as sequences.
Currently, type members, enumerators, and parameters are all represented
by tuples in the Python bindings. This is awkward to document and
implement. Instead, let's replace these tuples with proper types,
starting with the easiest one, TypeEnumerator. This one still makes
sense to treat as a sequence so that it can be unpacked as (name,
value).
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.
drgn.helpers has a couple of undocumented generic helpers. We might as
well document them. They're using type hints, so we need to use a sphinx
extension that strips the type hints out of the signature and adds them
to the documentation. We can also do the same for execscript().
Hopefully it can be used for the C extension documentation in the
future, too.
