This is a change to how we represent type subsitution in the AST.
Instead of only storing the replaced type, we track the templated
entity we are substituting, plus an index.
We modify MLTAL to track the templated entity at each level.
Otherwise, it's much more expensive to go from the template parameter back
to the templated entity, and not possible to do in some cases, as when
we instantiate outer templates, parameters might still reference the
original entity.
This also allows us to very cheaply lookup the templated entity we saw in
the naming context and find the corresponding argument it was replaced
from, such as for implementing template specialization resugaring.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D131858
There's many instances in clang tidy checks where owning strings are used when we already have a stable string from the options, so using a StringRef makes much more sense.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D124341
`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
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
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
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
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
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
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
Removed the uses of the allOf() matcher inside node matchers that are implicit
allOf(). Replaced uses of allOf() with the explicit node matcher where it makes
matchers more readable. Replace anyOf(hasName(), hasName(), ...) with the more
efficient and readable hasAnyName().
llvm-svn: 347520
New option added to these three checks to be able to silence false positives on
types that are intentionally passed by value or copied. Such types are e.g.
intrusive reference counting pointer types like llvm::IntrusiveRefCntPtr. The
new option is named WhiteListTypes and can contain a semicolon-separated list of
names of these types. Regular expressions are allowed. Default is empty.
Differential Revision: https://reviews.llvm.org/D52727
llvm-svn: 344340
Summary:
This will prevent the check warning the variables which have been
implicitly added by compiler, like the following case (in for-range loop):
the variable '__end' is copy-constructed from a const reference...
Reviewers: alexfh
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D25911
llvm-svn: 286186
Summary:
Also trigger the check in the following case:
void foo() {
ExpensiveToCopy Obj;
const auto UnnecessaryCopy = Obj.constReference();
Obj.onlyUsedAsConst();
}
i.e. when the object the method is called on is not const but is never
modified.
Reviewers: alexfh, fowles
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D20010
llvm-svn: 271239
Summary:
This is a step forward cleaning up the namespaces in clang-tidy/utils.
There is no behavior change.
Reviewers: alexfh
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D19819
llvm-svn: 268356
Summary: Extends the UnnecessaryCopyInitialization to detect copies of local variables and parameters that are unneeded.
Patch by Matt Kulukundis!
Reviewers: alexfh, hokein
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D18149
llvm-svn: 264146
Summary:
Move code shared between UnnecessaryCopyInitialization and ForRangeCopyCheck into utilities files.
Add more test cases for UnnecessaryCopyInitialization and disable fixes inside of macros.
Reviewers: alexfh
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D17488
llvm-svn: 262781
Summary: Since local static variables can outlive other local variables exclude them from the unnecessary copy initialization check.
Reviewers: alexfh
Patch by Felix Berger!
Differential Revision: http://reviews.llvm.org/D15822
llvm-svn: 256636
Summary:
The patch adds a new ClangTidy check that detects when expensive-to-copy types are unnecessarily copy initialized from a const reference that has the same or are larger scope than the copy.
It currently only detects this when the copied variable is const qualified. But this will be extended to non const variables if they are only used in a const fashion.
Reviewers: alexfh
Subscribers: cfe-commits
Patch by Felix Berger!
Differential Revision: http://reviews.llvm.org/D15623
llvm-svn: 256632
Matheus Izvekov