Currently, there is basically just one clang-tidy check to impose
some sanity limits on functions - `clang-tidy-readability-function-size`.
It is nice, allows to limit line count, total number of statements,
number of branches, number of function parameters (not counting
implicit `this`), nesting level.
However, those are simple generic metrics. It is still trivially possible
to write a function, which does not violate any of these metrics,
yet is still rather unreadable.
Thus, some additional, slightly more complicated metric is needed.
There is a well-known [[ https://en.wikipedia.org/wiki/Cyclomatic_complexity | Cyclomatic complexity]], but certainly has its downsides.
And there is a [[ https://www.sonarsource.com/docs/CognitiveComplexity.pdf | COGNITIVE COMPLEXITY by SonarSource ]], which is available for opensource on https://sonarcloud.io/.
This check checks function Cognitive Complexity metric, and flags
the functions with Cognitive Complexity exceeding the configured limit.
The default limit is `25`, same as in 'upstream'.
The metric is implemented as per [[ https://www.sonarsource.com/docs/CognitiveComplexity.pdf | COGNITIVE COMPLEXITY by SonarSource ]] specification version 1.2 (19 April 2017), with two notable exceptions:
* `preprocessor conditionals` (`#ifdef`, `#if`, `#elif`, `#else`,
`#endif`) are not accounted for.
Could be done. Currently, upstream does not account for them either.
* `each method in a recursion cycle` is not accounted for.
It can't be fully implemented, because cross-translational-unit
analysis would be needed, which is not possible in clang-tidy.
Thus, at least right now, i completely avoided implementing it.
There are some further possible improvements:
* Are GNU statement expressions (`BinaryConditionalOperator`) really free?
They should probably cause nesting level increase,
and complexity level increase when they are nested within eachother.
* Microsoft SEH support
* ???
Reviewed By: aaron.ballman, JonasToth, lattner
Differential Revision: https://reviews.llvm.org/D36836
Some projects do not use the TEMP_FAILURE_RETRY macro but define their
own one, as not to depend on glibc / Bionic details. By allowing the
user to override the list of macros, these projects can also benefit
from this check.
Differential Revision: https://reviews.llvm.org/D83144
Create targets `check-clang-extra-clang-tidy`, `check-clang-extra-clang-query`
similar to how `check-clang-sema`, `check-clang-parser`, etc. are
auto-generated from the directory structure.
This allows running only a particular sub-tool's tests, not having to wait
through the entire `check-clang-tools` execution.
Differential Revision: http://reviews.llvm.org/D84176
Finds member initializations in the constructor body which can be placed
into the initialization list instead. This does not only improves the
readability of the code but also affects positively its performance.
Class-member assignments inside a control statement or following the
first control statement are ignored.
Differential Revision: https://reviews.llvm.org/D71199
Placement new operators on non-object types cause crash in
`bugprone-misplaced-pointer-arithmetic-in-alloc`. This patch fixes this
issue.
Differential Revision: https://reviews.llvm.org/D87683
Instead of using CLANG_ENABLE_STATIC_ANALYZER for use of the
static analyzer in both clang and clang-tidy, add a second
toggle CLANG_TIDY_ENABLE_STATIC_ANALYZER.
This allows enabling the static analyzer in clang-tidy while
disabling it in clang.
Differential Revison: https://reviews.llvm.org/D87118
The altera struct pack align lint check finds structs that are inefficiently
packed or aligned and recommends packing/aligning of the structs using the
packed and aligned attributes as needed in a warning.
Commit `rGf5fd7486d6c0` caused a buildbot failure because exceptions are
disabled by default on one of the buildbots. This patch forcibly enables
exceptions for the affected test.
Checking the same condition again in a nested `if` usually make no sense,
except if the value of the expression could have been changed between
the two checks. Although compilers may optimize this out, such code is
suspicious: the programmer may have meant to check something else.
Therefore it is worth to find such places in the code and notify the
user about the problem.
This patch implements a basic check for this problem. Currently it
only detects redundant conditions where the condition is a variable of
integral type. It also detects the possible bug if the variable is in an
//or// or //and// logical expression in the inner if and/or the variable
is in an //and// logical expression in the outer if statement. Negated
cases are not handled yet.
Differential Revision: https://reviews.llvm.org/D81272
Finds member initializations in the constructor body which can
be placed to the member initializers of the constructor instead.
This does not only improves the readability of the code but also
affects positively its performance. Class-member assignments
inside a control statement or following the first control
statement are ignored.
Differential Revision: https://reviews.llvm.org/D71199
This checker appears to be intentionally not diagnosing cases where an
operator appearing in a duplicated expression might have side-effects;
Clang is now modeling fold-expressions as having an unresolved operator
name within them, so they now trip up this check.
When checking for the style of a decl that isn't in the main file, the check will now search for the configuration that the included files uses to gather the style for its decls.
This can be useful to silence warnings in header files that follow a different naming convention without using header-filter to silence all warnings(even from other checks) in the header file.
Reviewed By: aaron.ballman, gribozavr2
Differential Revision: https://reviews.llvm.org/D84814
Ordering of options isn't important so an `llvm::StringMap` is a much better container for this purpose.
Reviewed By: gribozavr2
Differential Revision: https://reviews.llvm.org/D84868
Handle insertion fix-its when removing incompatible errors by introducting a new EventType `ET_Insert`
This has lower prioirty than End events, but higher than begin.
Idea being If an insert is at the same place as a begin event, the insert should be processed first to reduce unnecessary conflicts.
Likewise if its at the same place as an end event, process the end event first for the same reason.
This also fixes https://bugs.llvm.org/show_bug.cgi?id=46511.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D82898
The previous fix for this, https://reviews.llvm.org/D76761, Passed test cases but failed in the real world as std::string has a non trivial destructor so creates a CXXBindTemporaryExpr.
This handles that shortfall and updates the test case std::basic_string implementation to use a non trivial destructor to reflect real world behaviour.
Reviewed By: gribozavr2
Differential Revision: https://reviews.llvm.org/D84831
Following on fcf7cc268f and 672207c319 which granted checks the ability to read boolean configuration arguments as `true` or `false`.
This enables storing the options back to the configuration file using `true` and `false`.
This is in line with how clang-format dumps boolean options in its style config.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D83053
This implements the default(firstprivate) clause as defined in OpenMP
Technical Report 8 (2.22.4).
Reviewed By: jdoerfert, ABataev
Differential Revision: https://reviews.llvm.org/D75591
The check assumed the matched function call has 3 arguments, but the
matcher didn't guaranteed that.
Differential Revision: https://reviews.llvm.org/D83301
The block arguments in dispatch_async() and dispatch_after() are
guaranteed to escape. If those blocks capture any pointers with the
noescape attribute then it is an error.
Added a 'RefactorConditionVariables' option to control how the check handles condition variables
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D82824
Extend the default string like classes to include `std::basic_string_view`.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D82720
In the process of running this check on a large codebase I found a
number of limitations, and thought I would pass on my fixes for
possible integration upstream:
* Templated function call operators are not supported
* Function object constructors are always used directly in the lambda
body, even if their arguments are not captured
* Placeholders with namespace qualifiers (std::placeholders::_1) are
not detected
* Lambda arguments should be forwarded to the stored function
* Data members from other classes still get captured with this
* Expressions (as opposed to variables) inside std::ref are not captured
properly
* Function object templates sometimes have their template arguments
replaced with concrete types
This patch resolves all those issues and adds suitable unit tests.
Prevent fixes being displayed if usages are found in the scratch buffer.
See [[ https://bugs.llvm.org/show_bug.cgi?id=46219 | Fix-It hints are being generated in the ScratchBuffer ]].
It may be wise down the line to put in a general fix in clang-tidy to prevent ScratchBuffer replacements being applied, but for now this will help.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D82162
Ignore paramater declarations of type `::llvm::Twine`, These don't suffer the same use after free risks as local twines.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D82281
Summary:
Currently, `cat` validates range selections before extracting the corresponding
source text. However, this means that any range inside a macro is rejected as an
error. This patch changes the implementation to first try to map the range to
something reasonable. This makes the behavior consistent with handling of ranges
used for selecting portions of the source to edit.
Also updates a clang-tidy lit-test for one of the checks which was affected by
this change.
Reviewers: gribozavr2, tdl-g
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D82126
Extend the `InheritParentConfig` support introduced in D75184 for the command line option `--config`.
The current behaviour of `--config` is to when set, disable looking for `.clang-tidy` configuration files.
This new behaviour lets you set `InheritParentConfig` to true in the command line to then look for `.clang-tidy` configuration files to be merged with what's been specified on the command line.
Reviewed By: DmitryPolukhin
Differential Revision: https://reviews.llvm.org/D81949
Zinovy Nis