Previously some checkers attached explicitly created program point tags
to some of the exploded graph nodes that they created. In most of the
checkers this ad-hoc tagging only affected the debug dump of the
exploded graph (and they weren't too relevant for debugging) so this
commit removes them.
There were two checkers where the tagging _did_ have a functional role:
- In `RetainCountChecker` the presence of tags were checked by
`RefCountReportVisitor`.
- In `DynamicTypePropagation` the checker sometimes wanted to create two
identical nodes and had to apply an explicit tag on the second one to
avoid "caching out".
In these two situations I preserved the tags but switched to using
`SimpleProgramPointTag` instead of `CheckerProgramPointTag` because
`CheckerProgramPointTag` didn't provide enough benefits to justify its
existence.
Note that this commit depends on the earlier commit "[analyzer] Fix
tagging of PostAllocatorCall" ec96c0c072ef3f78813c378949c00e1c07aa44e5
and would introduce crashes when cherry-picked onto a branch that
doesn't contain that commit.
For more details about the background see the discourse thread
https://discourse.llvm.org/t/role-of-programpointtag-in-the-static-analyzer/
As a tangentially related changes, this commit also adds some comments
to document the surprising behavior of `CheckerContext::addTransition`
and an assertion in the constructor of `PathSensitiveBugReport` to get a
more readable crash dump in the case when the report is constructed with
`nullptr` as the `ErrorNode`. (This can happen due to "caching out".)
These are identified by misc-include-cleaner. I've filtered out those
that break builds. Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.
The checker classes (i.e. classes derived from `CheckerBase` via the
utility template `Checker<...>`) act as intermediates between the user
and the analyzer engine, so they have two interfaces:
- On the frontend side, they have a public name, can be enabled or
disabled, can accept checker options and can be reported as the source
of bug reports.
- On the backend side, they can handle various checker callbacks and
they "leave a mark" on the `ExplodedNode`s that are created by them.
(These `ProgramPointTag` marks are internal: they appear in debug logs
and can be queried by checker logic; but the user doesn't see them.)
In a significant majority of the checkers there is 1:1 correspondence
between these sides, but there are also many checker classes where
several related user-facing checkers share the same backend class.
Historically each of these "multi-part checker" classes had its own
hacks to juggle its multiple names, which led to lots of ugliness like
lazy initialization of `mutable std::unique_ptr<BugType>` members and
redundant data members (when a checker used its custom `CheckNames`
array and ignored the inherited single `Name`).
My recent commit 27099982da2f5a6c2d282d6b385e79d080669546 tried to unify
and standardize these existing solutions to get rid of some of the
technical debt, but it still used enum values to identify the checker
parts within a "multi-part" checker class, which led to some ugliness.
This commit introduces a new framework which takes a more direct,
object-oriented approach: instead of identifying checker parts with
`{parent checker object, index of part}` pairs, the parts of a
multi-part checker become stand-alone objects that store their own name
(and enabled/disabled status) as a data member.
This is implemented by separating the functionality of `CheckerBase`
into two new classes: `CheckerFrontend` and `CheckerBackend`. The name
`CheckerBase` is kept (as a class derived from both `CheckerFrontend`
and `CheckerBackend`), so "simple" checkers that use `CheckerBase` and
`Checker<...>` continues to work without changes. However we also get
first-class support for the "many frontends - one backend" situation:
- The class `CheckerFamily<...>` works exactly like `Checker<...>` but
inherits from `CheckerBackend` instead of `CheckerBase`, so it won't
have a superfluous single `Name` member.
- Classes deriving from `CheckerFamily` can freely own multiple
`CheckerFrontend` data members, which are enabled within the
registration methods corresponding to their name and can be used to
initialize the `BugType`s that they can emit.
In this scheme each `CheckerFamily` needs to override the pure virtual
method `ProgramPointTag::getTagDescription()` which returns a string
which represents that class for debugging purposes. (Previously this
used the name of one arbitrary sub-checker, which was passable for
debugging purposes, but not too elegant.)
I'm planning to implement follow-up commits that convert all the
"multi-part" checkers to this `CheckerFamily` framework.
In the static analyzer codebase we have a traditional pattern where a
single checker class (and its singleton instance) acts as the
implementation of several (user-facing or modeling) checkers that have
shared state and logic, but have their own names and can be enabled or
disabled separately.
Currently these multipart checker classes all reimplement the same
boilerplate logic to store the enabled/disabled state, the name and the
bug types associated with the checker parts. This commit extends
`CheckerBase`, `BugType` and the checker registration process to offer
an easy-to-use alternative to that boilerplate (which includes the ugly
lazy initialization of `mutable std::unique_ptr<BugType>`s).
In this new framework the single-part checkers are internally
represented as "multipart checkers with just one part" (because this way
I don't need to reimplement the same logic twice) but this does not
require any changes in the code of simple single-part checkers.
I do not claim that these multi-part checkers are perfect from an
architectural point of view; but they won't suddenly disappear after
many years of existence, so we might as well introduce a clear framework
for them. (Switching to e.g. 1:1 correspondence between checker classes
and checker names would be a prohibitively complex change.)
This PR ports `DivZeroChecker` to the new framework as a proof of
concept. I'm planning to do a series of follow-up commits to port the
rest of the multi-part checker.
The method name `getCheckerName` would imply "get the name of the
checker associated with `this`", so it's suitable for e.g.
`BugType::getCheckerName` -- but a method that just "gets the name of
`this`" should be simply called `getName`.
This change eliminates the redundant and ugly pattern
`Checker->getCheckerName()` and helps to visually distinguish this
method from `BugType::getCheckerName`.
In the constructor of `BugType` the call of this method was completely
removed (instead of just changing the name) because that call was dead
code (when the data member `Checker` is non-null, the string stored in
`CheckerName` is irrelevant) and was often querying the name of the
checker before it was properly initialized.
Moreover, in `ReturnValueChecker.cpp` the static helper function
`getName` (which gets a function name from a `CallEvent`) was renamed to
the more specific `getFunctionName` to avoid the name collision.
This change is yet another cleanup commit before my planned changes that
would add support for multi-part checkers to this method.
`CheckerNameRef` is a trivial wrapper around a `StringRef` which is
guaranteed to be owned by the `CheckerRegistry` (the only `friend` of
the class) because other code can't call the private constructor.
This class had offered two ways to recover the plain `StringRef`: an an
`operator StringRef()` for implicit conversion and a method `StringRef
getName()` which could be called explicitly.
However this method name was really confusing, because it implies "get
the name of this object" instead of "get this name as a plain
`StringRef`"; so I removed it from the codebase and used
`static_cast<StringRef>` in the two locations where the cast wasn't
performed implicitly.
This commit "prepares the ground" for planned improvements in checker
name handling.
Traditionally, clang-tidy uses the term check, and the analyzer uses checker,
but in the very early years, this wasn't the case, and code originating from the
early 2010's still incorrectly refer to checkers as checks.
This patch attempts to hunt down most of these, aiming to refer to checkers as
checkers, but preserve references to callback functions (like checkPreCall) as
checks.
Differential Revision: https://reviews.llvm.org/D67140
llvm-svn: 371760
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
The GDMIndex functions return a pointer that's used as a key for looking up
data, but addresses of local statics defined in header files aren't the same
across shared library boundaries and the result is that analyzer plugins
can't access this data.
Event types are uniqued by using the addresses of a local static defined
in a header files, but it isn't the same across shared library boundaries
and plugins can't currently handle ImplicitNullDerefEvents.
Patches by Joe Ranieri!
Differential Revision: https://reviews.llvm.org/D52905
Differential Revision: https://reviews.llvm.org/D52906
llvm-svn: 344823
This implements FIXME from Checker.cpp (FIXME: We want to return the package + name of the checker here.) and replaces hardcoded checker names with the new ones obtained via getCheckName().getName().
llvm-svn: 201525
Summary:
In clang-tidy we'd like to know the name of the checker producing each
diagnostic message. PathDiagnostic has BugType and Category fields, which are
both arbitrary human-readable strings, but we need to know the exact name of the
checker in the form that can be used in the CheckersControlList option to
enable/disable the specific checker.
This patch adds the CheckName field to the CheckerBase class, and sets it in
the CheckerManager::registerChecker() method, which gets them from the
CheckerRegistry.
Checkers that implement multiple checks have to store the names of each check
in the respective registerXXXChecker method.
Reviewers: jordan_rose, krememek
Reviewed By: jordan_rose
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2557
llvm-svn: 201186
Original log:
Convert ProgramStateRef to a smart pointer for managing the reference counts of ProgramStates. This leads to a slight memory
improvement, and a simplification of the logic for managing ProgramState objects.
# Please enter the commit message for your changes. Lines starting
llvm-svn: 149339
Original log:
Convert ProgramStateRef to a smart pointer for managing the reference counts of ProgramStates. This leads to a slight memory
improvement, and a simplification of the logic for managing ProgramState objects.
llvm-svn: 149336
Having a notion of an actual ProgramPointTag will aid in introspection of the analyzer's behavior.
For example, the GraphViz output of the analyzer will pretty-print the tags in a useful manner.
llvm-svn: 137529
Eventually there will also be a lib/StaticAnalyzer/Frontend that will handle initialization and checker registration.
Yet another library to avoid cyclic dependencies between Core and Checkers.
llvm-svn: 125124
