This option allows callers to disable the warning from
https://clang.llvm.org/extra/clang-tidy/checks/performance-move-const-arg.html
that would warn on the following
```
void f(const string &s);
string s;
f(std::move(s)); // ALLOWED if performance-move-const-arg.CheckMoveToConstRef=false
```
The reason people might want to disable this check, is because it allows
callers to use `std::move()` or not based on local reasoning about the
argument, and without having to care about how the function `f` accepts
the argument. Indeed, `f` might accept the argument by const-ref today,
but change to by-value tomorrow, and if the caller had moved the
argument that they were finished with, the code would work as
efficiently as possible regardless of how `f` accepted the parameter.
Reviewed By: ymandel
Differential Revision: https://reviews.llvm.org/D119370
`isConstRefReturningMethodCall` should be considering
`CXXOperatorCallExpr` in addition to `CXXMemberCallExpr`. Clang considers
these to be distinct (`CXXOperatorCallExpr` derives from `CallExpr`, not
`CXXMemberCallExpr`), but we don't care in the context of this
check.
This is important because of
`std::vector<Expensive>::operator[](size_t) const`.
Differential Revision: https://reviews.llvm.org/D114249
Run clang-tidy on all source files under `clang-tools-extra/clang-tidy`
with `-header-filter=clang-tidy.*` and make suggested corrections.
Differential Revision: https://reviews.llvm.org/D112864
We're missing all cases where the return value is a type alias.
Unfortunately, this includes things we care about, such as
`std::vector<T>::operator[]` (return value is `const_reference`,
not `const T&`).
Match the canonical type instead.
Differential Revision: https://reviews.llvm.org/D112722
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
This can happen when a template with two parameter types is instantiated with a
single type. The fix would only be valid for this instantiation but fail for
others that rely on an implicit type conversion.
The test cases illustrate when the check should trigger and when not.
Differential Revision: https://reviews.llvm.org/D106011
When deleting the copy assignment statement because copied variable is not used
only remove trailing comments on the same line.
Differential Revision: https://reviews.llvm.org/D105734
Reviewed-by: ymandel
Structured bindings can currently trigger the check and lead to a wrong
fix. Because the DecompositionDecl itself is not used and the check does not
iterate through its the decl's bindings to verify whether the bindings' holding
vars are used this leads to the whole statement to be deleted.
To support structured bindings properly 3 cases would need to be considered.
1. All holding vars are not used -> The statement can be deleted.
2. All holding vars are used as const or not used -> auto can be converted to const auto&.
3. Neither case is true -> leave unchanged.
In the check we'll have to separate the logic that determines this from the code
that produces the diagnostic and fixes and first determine which of the cases
we're dealing with before creating fixes.
Since this is a bigger refactoring we'll disable structured bindings for now to
prevent incorrect fixes.
Differential Revision: https://reviews.llvm.org/D105727
Reviewed-by: ymandel
This fixes false positive cases where a reference is initialized outside of a
block statement and then its initializing variable is modified. Another case is
when the looped over container is modified.
Differential Revision: https://reviews.llvm.org/D103021
Reviewed-by: ymandel
This fixes a false positive case where for instance a pointer is obtained and declared using `auto`.
Differential Revision: https://reviews.llvm.org/D103018
Reviewed-by: ymandel
It is not useful to keep the statement around and can lead to compiler
warnings when -Wall (-Wunused-variable specifically) turned on.
Differential Revision: https://reviews.llvm.org/D102175
Reviewed-by: ymandel
This disables the check for false positive cases where implicit type conversion
through either an implicit single argument constructor or a member conversion
operator is triggered when constructing the loop variable.
Fix the test cases that meant to cover these cases.
Differential Revision: https://reviews.llvm.org/D97577
Reviewed-by: hokein
Fix up cases where diag is called by piecing together a string in favour of placeholders.
Fix up cases where select could be used instead of duplicating the message for sake of 1 word difference.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D97488
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
Use mapAnyOf() and matchers based on it.
Use of binaryOperation() means that modernize-loop-convert and
readability-container-size-empty can now be used with rewritten binary
operators.
Differential Revision: https://reviews.llvm.org/D94131
Extend the check to not only look at the variable the unnecessarily copied
variable is initialized from, but also ensure that any variable the old variable
references is not modified.
Extend DeclRefExprUtils to also count references and pointers to const assigned
from the DeclRef we check for const usages.
Reviewed-by: aaron.ballman
Differential Revision: https://reviews.llvm.org/D91893
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
Since its call operator is const but can modify the state of its underlying
functor we cannot tell whether the copy is necessary or not.
This avoids false positives.
Reviewed-by: aaron.ballman, gribozavr2
Differential Revision: https://reviews.llvm.org/D89332
Simplified how `IncludeInserter` is used in Checks by abstracting away the SourceManager and PPCallbacks inside the method `registerPreprocessor`.
Changed checks that use `IncludeInserter` to no longer use a `std::unique_ptr`, instead the IncludeInserter is just a member of the class thats initialized with an `IncludeStyle`.
Saving an unnecessary allocation.
This results in the removal of the field `IncludeSorter::IncludeStyle` from the checks, as its wrapped in the `IncludeInserter`.
No longer need to create an instance of the `IncludeInserter` in the registerPPCallbacks, now that method only needs to contain:
```
Inserter.registerPreprocessor(PP);
```
Also added a helper method to `IncludeInserter` called `createMainFileInclusionInsertion`, purely sugar but does better express intentions.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D83680
Reland b9306fd after fixing the issue causing mac builds to fail unittests.
Following on from D77085, I was never happy with the passing a mapping to the option get/store functions. This patch addresses this by using explicit specializations to handle the serializing and deserializing of enum options.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D82188
Extend the default string like classes to include `std::basic_string_view`.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D82720
Added some sanity checks to figure out the cause of a (seemingly unrelated) test failure on mac.
These can be removed should no issues arise on that platform again.
Following on from D77085, I was never happy with the passing a mapping to the option get/store functions. This patch addresses this by using explicit specializations to handle the serializing and deserializing of enum options.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D82188
Fix various tool libraries not to link to clang's .a libraries and dylib
simultaneously. This may cause breakage, in particular through
duplicate command-line option declarations.
Differential Revision: https://reviews.llvm.org/D81967
Summary:
The AST is different in C++17 in that there is no MaterializeTemporaryExpr for in the AST for a loop variable that is initialized from an iterator that returns its elements by value.
Account for this by checking that the variable is not initialized by an operator* call that returns a value type.
Reviewers: gribozavr2
Reviewed By: gribozavr2
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D79440
Summary: This was done with a script that looks for calls to Options.get(GlobalOrLocal) that take an integer for the second argument and the result is either compared not equal to 0 or implicitly converted to bool. There may be other occurances
Reviewers: aaron.ballman, alexfh, gribozavr2
Reviewed By: aaron.ballman
Subscribers: wuzish, nemanjai, xazax.hun, kbarton, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D77831
This reverts commit 97aa593a83 as it
causes problems (PR45453) https://reviews.llvm.org/D77574#1966321.
This additionally adds an explicit reference to FrontendOpenMP to
clang-tidy where ASTMatchers is used.
This is hopefully just a temporary solution. The dependence on
`FrontendOpenMP` from `ASTMatchers` should be handled by CMake
implicitly, not us explicitly.
Reviewed By: aheejin
Differential Revision: https://reviews.llvm.org/D77666
Summary: Change all checks that take enums as configuration to use enum specific methods in `ClangTidyCheck::OptionsView`.
Reviewers: aaron.ballman, alexfh
Reviewed By: aaron.ballman
Subscribers: wuzish, nemanjai, kbarton, arphaman, xazax.hun, cfe-commits
Tags: #clang, #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D76606
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Summary:
This patch extends the already existing facility to add 'const' to variables
to be more flexible and correct. The previous version did not consider pointers
as value AND pointee. For future automatic introduction for const-correctness
this shortcoming needs to be fixed.
It always allows configuration where the 'const' token is inserted, either on
the left side (if possible) or the right side.
It adds many unit-tests to the utility-function that did not exist before, as
the function was implicitly tested through clang-tidy checks. These
tests were not changed, as the API is still compatible.
Reviewers: aaron.ballman, hokein, alexfh, shuaiwang, lebedev.ri
Reviewed By: aaron.ballman
Subscribers: jdoerfert, mgorny, xazax.hun, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D54395
Nathan James