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
Fixes bug http://bugs.llvm.org/show_bug.cgi?id=49000.
This patch allows Clang-Tidy checks to do
diag(X->getLocation(), "text") << Y->getSourceRange();
and get the highlight of `Y` as expected:
warning: text [blah-blah]
xxx(something)
^ ~~~~~~~~~
Reviewed-By: aaron.ballman, njames93
Differential Revision: http://reviews.llvm.org/D98635
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
Following a discussion about the current state of this check on the 12.X branch, it was decided to purge the check as it wasn't in a fit to release state, see https://llvm.org/PR49318.
This check has since had some of those issues addressed and should be good for the next release cycle now, pending any more bug reports about it.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D97275
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
The run-clang-tidy.py helper script is supposed to be used by the
user, hence it should be placed in the user's PATH. Some
distributions, like Gentoo [1], won't have it in PATH unless it is
installed in bin/.
Furthermore, installed scripts in PATH usually do not carry a filename
extension, since there is no need to know that this is a Python
script. For example Debian and Ubuntu already install this script as
'run-clang-tidy' [2] and hence build systems like Meson also look for
this name first [3]. Hence we install run-clang-tidy.py as
run-clang-tidy, as suggested by Sylvestre Ledru [4].
1: https://bugs.gentoo.org/753380
2: 60aefb1417/debian/clang-tidy-X.Y.links.in (L2)
3: b6dc4d5e5c/mesonbuild/scripts/clangtidy.py (L44)
4: https://reviews.llvm.org/D90972#2380640
Reviewed By: sylvestre.ledru, JonasToth
Differential Revision: https://reviews.llvm.org/D90972
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
This allows for matching the constructors std::string has in common with
std::string_view.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D91015
The altera kernel name restriction check finds kernel files and include
directives whose filename is "kernel.cl", "Verilog.cl", or "VHDL.cl".
Such kernel file names cause the Altera Offline Compiler to generate
intermediate design files that have the same names as certain internal
files, which leads to a compilation error.
As per the "Guidelines for Naming the Kernel" section in the "Intel FPGA
SDK for OpenCL Pro Edition: Programming Guide."
This reverts the reversion from 43a38a6523.
SIG30-C. Call only asynchronous-safe functions within signal handlers
First version of this check, only minimal list of functions is allowed
("strictly conforming" case), for C only.
Differential Revision: https://reviews.llvm.org/D87449
The altera kernel name restriction check finds kernel files and include
directives whose filename is "kernel.cl", "Verilog.cl", or "VHDL.cl".
Such kernel file names cause the Altera Offline Compiler to generate
intermediate design files that have the same names as certain internal
files, which leads to a compilation error.
As per the "Guidelines for Naming the Kernel" section in the "Intel FPGA
SDK for OpenCL Pro Edition: Programming Guide."
Changed two references to developers as "he" or "him" to the more neutral "they".
Reviewed By: JDevlieghere, sylvestre.ledru
Differential Revision: https://reviews.llvm.org/D78807
Added option `ScopedEnumConstant(Prefix|Case|Suffix)` to readability-identitied-naming.
This controls the style for constants in scoped enums, declared as enum (class|struct).
If this option is unspecified the EnumConstant style will be used instead.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D89407
Enables support for transforming loops of the form
```
for (auto I = Cont.rbegin(), E = Cont.rend(); I != E;++I)
```
This is done automatically in C++20 mode using `std::ranges::reverse_view` but there are options to specify a different function to reverse iterator over a container.
This is the first step, down the line I'd like to possibly extend this support for array based loops
```
for (unsigned I = Arr.size() - 1;I >=0;--I) Arr[I]...
```
Currently if you pass a reversing function with no header in the options it will just assume that the function exists, however as we have the ASTContext it may be as wise to check before applying, or at least lower the confidence level if we can't find it.
Reviewed By: alexfh
Differential Revision: https://reviews.llvm.org/D82089
Stephen Concannon