Finds base classes and structs whose destructor is neither public and
virtual nor protected and non-virtual.
A base class's destructor should be specified in one of these ways to
prevent undefined behaviour.
Fixes are available for user-declared and implicit destructors that are
either public and non-virtual or protected and virtual.
This check implements C.35 [1] from the CppCoreGuidelines.
Reviewed By: aaron.ballman, njames93
Differential Revision: http://reviews.llvm.org/D102325
[1]: http://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Rc-dtor-virtual
Add a check for enforcing minimum length for variable names. A default
minimum length of three characters is applied to regular variables
(including function parameters). Loop counters and exception variables
have a minimum of two characters. Additionally, the 'i', 'j' and 'k'
are accepted as legacy values.
All three sizes, as well as the list of accepted legacy loop counter
names are configurable.
FixIt, and add support for initialization check of scoped enum
In C++, the enumeration is never Integer, and the enumeration condition judgment is added to avoid compiling errors when it is initialized to an integer.
Add support for initialization check of scope enum.
As the following case show, clang-tidy will give a wrong automatic fix:
enum Color {Red, Green, Blue};
enum class Gender {Male, Female};
void func() {
Color color; // Color color = 0; <--- fix bug
Gender gender; // <--- no warning
}
Reviewd By: aaron.ballman, whisperity
Differential Revision: http://reviews.llvm.org/D106431
Many concepts emulation libraries, such as the one found in Range v3, tend to
use non-type template parameters for the enable_if type expression, due to
their versatility in template functions and constructors containing variadic
template parameter packs.
Unfortunately the bugprone-forwarding-reference-overload check does not
handle non-type template parameters, as was first noted in this bug report:
https://bugs.llvm.org/show_bug.cgi?id=38081
This patch fixes this long standing issue and allows for the check to be suppressed
with the use of a non-type template parameter containing enable_if or enable_if_t in
the type expression, so long as it has a default literal value.
Add string list option of type names analagous to `AllowedTypes` which lets
users specify a list of ExcludedContainerTypes.
Types matching this list will not trigger the check when an expensive variable
is copy initialized from a const accessor method they provide, i.e.:
```
ExcludedContainerTypes = 'ExcludedType'
void foo() {
ExcludedType<ExpensiveToCopy> Container;
const ExpensiveToCopy NecessaryCopy = Container.get();
}
```
Even though an expensive to copy variable is copy initialized the check does not
trigger because the container type is excluded.
This is useful for container types that don't own their data, such as view types
where modification of the returned references in other places cannot be reliably
tracked, or const incorrect types.
Differential Revision: https://reviews.llvm.org/D106173
Reviewed-by: ymandel
Finds function calls where the call arguments might be provided in an
incorrect order, based on the comparison (via string metrics) of the
parameter names and the argument names against each other.
A diagnostic is emitted if an argument name is similar to a *different*
parameter than the one currently passed to, and it is sufficiently
dissimilar to the one it **is** passed to currently.
False-positive warnings from this check are useful to indicate bad
naming convention issues, even if a swap isn't necessary.
This check does not generate FixIts.
Originally implemented by @varjujan as his Master's Thesis work.
The check was subsequently taken over by @barancsuk who added type
conformity checks to silence false positive matches.
The work by @whisperity involved driving the check's review and fixing
some more bugs in the process.
Reviewed By: aaron.ballman, alexfh
Differential Revision: http://reviews.llvm.org/D20689
Co-authored-by: János Varjú <varjujanos2@gmail.com>
Co-authored-by: Lilla Barancsuk <barancsuklilla@gmail.com>
While the original check's purpose is to identify potentially dangerous
functions based on the parameter types (as identifier names do not mean
anything when it comes to the language rules), unfortunately, such a plain
interface check rule can be incredibly noisy. While the previous
"filtering heuristic" is able to find many similar usages, there is an entire
class of parameters that should not be warned about very easily mixed by that
check: parameters that have a name and their name follows a pattern,
e.g. `text1, text2, text3, ...`.`
This patch implements a simple, but powerful rule, that allows us to detect
such cases and ensure that no warnings are emitted for parameter sequences that
follow a pattern, even if their types allow for them to be potentially mixed at a call site.
Given a threshold `k`, warnings about two parameters are filtered from the
result set if the names of the parameters are either prefixes or suffixes of
each other, with at most k letters difference on the non-common end.
(Assuming that the names themselves are at least `k` long.)
- The above `text1, text2` is an example of this. (Live finding from Xerces.)
- `LHS` and `RHS` are also fitting the bill here. (Live finding from... virtually any project.)
- So does `Qmat, Tmat, Rmat`. (Live finding from I think OpenCV.)
Reviewed By: aaron.ballman
Differential Revision: http://reviews.llvm.org/D97297
There are several types of functions and various reasons why some
"swappable parameters" cannot be fixed with changing the parameters' types, etc.
The most common example might be int `min(int a, int b)`... no matter what you
do, the two parameters must remain the same type.
The **filtering heuristic** implemented in this patch deals with trying to find
such functions during the modelling and building of the swappable parameter
range.
If the parameter currently scrutinised matches either of the predicates below,
it will be regarded as **not swappable** even if the type of the parameter
matches.
Reviewed By: aaron.ballman
Differential Revision: http://reviews.llvm.org/D78652
Adds a relaxation option ModelImplicitConversions which will make the check
report for cases where parameters refer to types that are implicitly
convertible to one another.
Example:
struct IntBox { IntBox(int); operator int(); };
void foo(int i, double d, IntBox ib) {}
Implicit conversions are the last to model in the set of things that are
reasons for the possibility of a function being called the wrong way which is
not always immediately apparent when looking at the function (signature or
call).
Reviewed By: aaron.ballman, martong
Differential Revision: http://reviews.llvm.org/D75041
Adds a relaxation option QualifiersMix which will make the check report for
cases where parameters refer to the same type if they only differ in qualifiers.
This makes cases, such as the following, not warned about by default, produce
a warning.
void* memcpy(void* dst, const void* src, unsigned size) {}
However, unless people meticulously const their local variables, unfortunately,
even such a function carry a potential swap:
T* obj = new T; // Not const!!!
void* buf = malloc(sizeof(T));
memcpy(obj, buf, sizeof(T));
// ^~~ ^~~ accidental swap here, even though the interface "specified" a const.
Reviewed By: aaron.ballman
Differential Revision: http://reviews.llvm.org/D96355
The base patch only deals with strict (canonical) type equality, which is
merely a subset of all the dangerous function interfaces that we intend to
find.
In addition, in the base patch, canonical type equivalence is not diagnosed in
a way that is immediately apparent to the user.
This patch extends the check with two features:
* Proper typedef diagnostics and explanations to the user.
* "Reference bind power" matching.
Case 2 is a necessary addition because in every case someone encounters a
function `f(T t, const T& tr)`, any expression that might be passed to either
can be passed to both. Thus, such adjacent parameter sequences should be
matched.
Reviewed By: aaron.ballman
Differential Revision: http://reviews.llvm.org/D95736
Finds function definitions where parameters of convertible types follow
each other directly, making call sites prone to calling the function
with swapped (or badly ordered) arguments.
Such constructs are usually the result of inefficient design and lack of
exploitation of strong type capabilities that are possible in the
language.
This check finds and flags **function definitions** and **not** call
sites!
Reviewed By: aaron.ballman, alexfh
Differential Revision: http://reviews.llvm.org/D69560
Within clang-tidy's NarrowingConversionsCheck.
* Allow opt-out of some common occurring patterns, such as:
- Implicit casts between types of equivalent bit widths.
- Implicit casts occurring from the return of a ::size() method.
- Implicit casts on size_type and difference_type.
* Allow opt-in of errors within template instantiations.
This will help projects adopt these guidelines iteratively.
Developed in conjunction with Yitzhak Mandelbaum (ymandel).
Patch by Stephen Concannon!
Differential Revision: https://reviews.llvm.org/D99543
This lint check is a part of the FLOCL (FPGA Linters for OpenCL) project
out of the Synergy Lab at Virginia Tech.
FLOCL is a set of lint checks aimed at FPGA developers who write code
in OpenCL.
The altera ID dependent backward branch lint check finds ID dependent
variables and fields used within loops, and warns of their usage. Using
these variables in loops can lead to performance degradation.
Overflows are never fun.
In most cases (in most of the code), they are rare,
because usually you e.g. don't have as many elements.
However, it's exceptionally easy to fall into this pitfail
in code that deals with images, because, assuming 4-channel 32-bit FP data,
you need *just* ~269 megapixel image to case an overflow
when computing at least the total byte count.
In [[ https://github.com/darktable-org/darktable | darktable ]], there is a *long*, painful history of dealing with such bugs:
* https://github.com/darktable-org/darktable/pull/7740
* https://github.com/darktable-org/darktable/pull/7419
* eea1989f2c
* 70626dd95b
* https://github.com/darktable-org/darktable/pull/670
* 38c69fb1b2
and yet they clearly keep resurfacing still.
It would be immensely helpful to have a diagnostic for those patterns,
which is what this change proposes.
Currently, i only diagnose the most obvious case, where multiplication
is directly widened with no other expressions inbetween,
(i.e. `long r = (int)a * (int)b` but not even e.g. `long r = ((int)a * (int)b)`)
however that might be worth relaxing later.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D93822
This is the only remaining check that creates `std::move` includes but doesn't add a `<utility>` include.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D97683
(this was originally part of https://reviews.llvm.org/D96281 and has been split off into its own patch)
If a macro is used within a function, the code inside the macro
doesn't make the code less readable. Instead, for a reader a macro is
more like a function that is called. Thus the code inside a macro
shouldn't increase the complexity of the function in which it is called.
Thus the flag 'IgnoreMacros' is added. If set to 'true' code inside
macros isn't considered during analysis.
This isn't perfect, as now the code of a macro isn't considered at all,
even if it has a high cognitive complexity itself. It might be better if
a macro is considered in the analysis like a function and gets its own
cognitive complexity. Implementing such an analysis seems to be very
complex (if possible at all with the given AST), so we give the user the
option to either ignore macros completely or to let the expanded code
count to the calling function's complexity.
See the code example from vgeof (originally added as note in https://reviews.llvm.org/D96281)
bool doStuff(myClass* objectPtr){
if(objectPtr == nullptr){
LOG_WARNING("empty object");
return false;
}
if(objectPtr->getAttribute() == nullptr){
LOG_WARNING("empty object");
return false;
}
use(objectPtr->getAttribute());
}
The LOG_WARNING macro itself might have a high complexity, but it do not make the
the function more complex to understand like e.g. a 'printf'.
By default 'IgnoreMacros' is set to 'false', which is the original behavior of the check.
Reviewed By: lebedev.ri, alexfh
Differential Revision: https://reviews.llvm.org/D98070
The default setting for CheckImplicitCasts was changed in
https://reviews.llvm.org/D32164 but the documentation was not updated.
This simple change just syncs the documentation with the behavior of
that checker.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D99991
This allows users to be more precise and exclude a type in a specific namespace
from triggering the check instead of excluding all types with the same
unqualified name.
This change should not interfere with correctly configured clang-tidy setups
since an AllowedType with "::" would never match.
Differential Revision: https://reviews.llvm.org/D98738
Reviewed-by: ymandel, hokein
This lint check is a part of the FLOCL (FPGA Linters for OpenCL)
project out of the Synergy Lab at Virginia Tech.
FLOCL is a set of lint checks aimed at FPGA developers who write code
in OpenCL.
The altera unroll loops check finds inner loops that have not been
unrolled, as well as fully-unrolled loops that should be partially
unrolled due to unknown loop bounds or a large number of loop
iterations.
Based on the Altera SDK for OpenCL: Best Practices Guide.
The deprecation notice was cherrypicked to the release branch in f8b3298924 so its safe to remove this for the 13.X release cycle.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D98612
We have no way to reason about the bool returned by try_emplace, so we
simply ignore any std::move()s that happen in a try_emplace argument.
A lot of the time in this situation, the code will be checking the
bool and doing something else if it turns out the value wasn't moved
into the map, and this has been causing false positives so far.
I don't currently have any intentions of handling "maybe move" functions
more generally.
Reviewed By: sammccall
Differential Revision: https://reviews.llvm.org/D98034
Often you are only interested in the overall cognitive complexity of a
function and not every individual increment. Thus the flag
'DescribeBasicIncrements' is added. If it is set to 'true', each increment
is flagged. Otherwise, only the complexity of function with complexity
of at least the threshold are flagged.
By default 'DescribeBasisIncrements' is set to 'true', which is the original behavior of the check.
Added a new test for different flag combinations.
(The option to ignore macros which was original part of this patch will be added in another path)
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D96281
- Create a separate section on silencing erroneous warnings and add more material to it
- Add note that the check is flow-sensitive but not path-sensitive
... For removal in next release cycle.
The clang warning that does the same thing is enabled by default and typically emits better diagnostics making this check surplus to requirements.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D97491
Added an option to control whether to apply the fixes found in notes attached to clang tidy errors or not.
Diagnostics may contain multiple notes each offering different ways to fix the issue, for that reason the default behaviour should be to not look at fixes found in notes.
Instead offer up all the available fix-its in the output but don't try to apply the first one unless `-fix-notes` is supplied.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D84924
Adds an option, `PreferResetCall`, currently defaulted to `false`, to the check.
When `true` the check will refactor by calling the `reset` member function.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D97630
This check registers an IncludeInserter, however the check itself doesn't actually emit any fixes or includes, so the inserter is redundant.
From what I can tell the fixes were removed in D26453(rL290051) but the inserter was left in, probably an oversight.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D97243
An option is added to the check to select wich set of functions is
defined as asynchronous-safe functions.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D90851
This lint check is a part of the FLOCL (FPGA Linters for OpenCL)
project out of the Synergy Lab at Virginia Tech.
FLOCL is a set of lint checks aimed at FPGA developers who write code
in OpenCL.
The altera single work item barrier check finds OpenCL kernel functions
that call a barrier function but do not call an ID function. These
kernel functions will be treated as single work-item kernels, which
could be inefficient or lead to errors.
Based on the "Altera SDK for OpenCL: Best Practices Guide."
While casting an (integral) pointer to an integer is obvious - you just get
the integral value of the pointer, casting an integer to an (integral) pointer
is deceivingly different. While you will get a pointer with that integral value,
if you got that integral value via a pointer-to-integer cast originally,
the new pointer will lack the provenance information from the original pointer.
So while (integral) pointer to integer casts are effectively no-ops,
and are transparent to the optimizer, integer to (integral) pointer casts
are *NOT* transparent, and may conceal information from optimizer.
While that may be the intention, it is not always so. For example,
let's take a look at a routine to align the pointer up to the multiple of 16:
The obvious, naive implementation for that is:
```
char* src(char* maybe_underbiased_ptr) {
uintptr_t maybe_underbiased_intptr = (uintptr_t)maybe_underbiased_ptr;
uintptr_t aligned_biased_intptr = maybe_underbiased_intptr + 15;
uintptr_t aligned_intptr = aligned_biased_intptr & (~15);
return (char*)aligned_intptr; // warning: avoid integer to pointer casts [misc-no-inttoptr]
}
```
The check will rightfully diagnose that cast.
But when provenance concealment is not the goal of the code, but an accident,
this example can be rewritten as follows, without using integer to pointer cast:
```
char*
tgt(char* maybe_underbiased_ptr) {
uintptr_t maybe_underbiased_intptr = (uintptr_t)maybe_underbiased_ptr;
uintptr_t aligned_biased_intptr = maybe_underbiased_intptr + 15;
uintptr_t aligned_intptr = aligned_biased_intptr & (~15);
uintptr_t bias = aligned_intptr - maybe_underbiased_intptr;
return maybe_underbiased_ptr + bias;
}
```
See also:
* D71499
* [[ https://www.cs.utah.edu/~regehr/oopsla18.pdf | Juneyoung Lee, Chung-Kil Hur, Ralf Jung, Zhengyang Liu, John Regehr, and Nuno P. Lopes. 2018. Reconciling High-Level Optimizations and Low-Level Code in LLVM. Proc. ACM Program. Lang. 2, OOPSLA, Article 125 (November 2018), 28 pages. ]]
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D91055
This extends the check for default initialization in arrays added in
547f89d607 to include scalar types and exclude them from the suggested fix for
make_unique/make_shared.
Rewriting std::unique_ptr<int>(new int) as std::make_unique<int>() (or for
other, similar trivial T) switches from default initialization to value
initialization, a performance regression for trivial T. For these use cases,
std::make_unique_for_overwrite is more suitable alternative.
Reviewed By: hokein
Differential Revision: https://reviews.llvm.org/D90392
Using bools instead of integers better conveys the expected value of the option.
Reviewed By: Eugene.Zelenko, aaron.ballman
Differential Revision: https://reviews.llvm.org/D92652
Checks for some thread-unsafe functions against a black list
of known-to-be-unsafe functions. Usually they access static variables
without synchronization (e.g. gmtime(3)) or utilize signals
in a racy way (e.g. sleep(3)).
The patch adds a check instead of auto-fix as thread-safe alternatives
usually have API with an additional argument
(e.g. gmtime(3) v.s. gmtime_r(3)) or have a different semantics
(e.g. exit(3) v.s. __exit(3)), so it is a rather tricky
or non-expected fix.
An option specifies which functions in libc should be considered
thread-safe, possible values are `posix`, `glibc`,
or `any` (the most strict check). It defaults to 'any' as it is
unknown what target libc type is - clang-tidy may be run
on linux but check sources compiled for other *NIX.
The check is used in Yandex Taxi backend and has caught
many unpleasant bugs. A similar patch for coroutine-unsafe API
is coming next.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D90944
The module will contain checks related to concurrent programming (including threads, fibers, coroutines, etc.).
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D91656
The idea of suppressing naming checks for variables is to support code bases that allow short variables named e.g 'x' and 'i' without prefix/suffixes or casing styles. This was originally proposed as a 'ShortSizeThreshold' however has been made more generic with a regex to suppress identifier naming checks for those that match.
Reviewed By: njames93, aaron.ballman
Differential Revision: https://reviews.llvm.org/D90282
std::string_view("") produces a string_view instance that compares
equal to std::string_view(), but requires more complex initialization
(storing the address of the string literal, rather than zeroing).
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D91009
Marco Gartmann