This PR aims to fix `performance-move-const-arg` #126515
## Changes
Enhanced the `performance-move-arg` check in Clang-Tidy to detect cases
where `std::move` is used
in **ternary operator expressions which was not being matched therefore
being tagged as a false negative**
## Testing
- A new mock class has been where the changes have been tested & all
tests pass
I'd appreciate any feedback since this is my first time contributing to
LLVM.
Tolerate fix-it breaking compilation when functions is used as pointers.
`isReferencedOutsideOfCallExpr` will visit the whole translate unit for
each matched function decls. It will waste lots of cpu time in some big
cpp files.
But the benefits of this validation are limited. Lots of function usage
are out of current translation unit.
After removing this validation step, the check profiling changes from
5.7 to 1.1 in SemaExprCXX.cpp, which is similar to version 18.
This patch improves, but doens't fully resolve the layering violation,
which stems from relying on Sema. There's one function that needs to
convert enumerator to a string (`buildQualifier` in
`FixItHintUtils.cpp`), but `Qualifiers::TQ` doesn't offer such function.
Even more, the set of enumerators is not complete compared to
`DeclSpec::TQ`, so I'm afraid that this would be a functional change.
If a add_clang_library call doesn't specify building as static or shared
library they are implicitly added to the list static libraries that is
linked in to clang-cpp shared library here.
315ba77406/clang/cmake/modules/AddClang.cmake (L107)
Because the clang-tools-extra libraries targets were declared after
clang-cpp they by luck never got linked to clang-cpp.
This change is required for clang symbol visibility macros on windows to
work correctly for clang tools since we need to distinguish if a target
being built will be importing or exporting clang symbols from the
clang-cpp DLL.
... so that downstream checks can override behaviour to do additional
processing.
Refactor the rest of the logic to `handleConstRefFix` (which is also
`virtual`).
This is otherwise and NFC.
This is similar to https://github.com/llvm/llvm-project/pull/73921 but
for `performance-unnecessary-value-param`.
Clang-Tidy unnecessary-value-param value param will be triggered for
templated functions if at least one instantiontion with expensive to
copy type is present in translation unit.
It is relatively common mistake to write lambda functions with auto
arguments for expensive to copy types.
…and operators that have non-const overloads.
This allows `unnecessary-copy-initialization` to warn on more cases.
The common case is a class with a a set of const/non-sconst overloads
(e.g. std::vector::operator[]).
```
void F() {
std::vector<Expensive> v;
// ...
const Expensive e = v[i];
}
```
This uses a more systematic approach for determining whcich
`DeclRefExpr`s mutate the underlying object: Instead of using a few
matchers, we walk up the AST until we find a parent that we can prove
cannot change the underlying object.
This allows us to handle most address taking and dereference, bindings
to value and const& variables, and track constness of pointee (see
changes in DeclRefExprUtilsTest.cpp).
This allows supporting more patterns in
`performance-unnecessary-copy-initialization`.
Those two patterns are relatively common:
```
const auto e = (*vector_ptr)[i]
```
and
```
const auto e = vector_ptr->at(i);
```
In our codebase, we have around 25% additional findings from
`performance-unnecessary-copy-initialization` with this change. I did
not see any additional false positives.
Enums without enumerators (empty) are now excluded from analysis as it's
not possible to peroperly determinate new narrowed type, and such enums
can be used in diffrent way, like as strong-types.
Closes#71544
Enforce a stricter match with the swap function signature, eliminating false-positives.
Fixes: #64303
Reviewed By: carlosgalvezp
Differential Revision: https://reviews.llvm.org/D157185
The modules build trips over this frequently because there is no textual
include of the tablegen output, but the module includes it.
Differential revision: https://reviews.llvm.org/D157119
Finds enum type definitions that could use smaller integral type as a base.
Reviewed By: xgupta
Differential Revision: https://reviews.llvm.org/D144135
add_new_check.py does not work properly for checks that
generate fixes in base class. Adding some comments to those
checks in order to fix list.rst generation.
We now display a simple note if the reason is that the used class does not
support move semantics.
This fixes llvm#62550
Reviewed By: PiotrZSL
Differential Revision: https://reviews.llvm.org/D153220
Added new checks
- `performance-noexcept-destructor`
- `performance-noexcept-swap`
Also added cppcoreguidlines aliases for the 2 new checks as well as `performance-noexcept-move-constructor`
This fixes llvm#62154
Reviewed By: PiotrZSL
Differential Revision: https://reviews.llvm.org/D148697
This check flags uses of `std::endl` on streams and suggests using the newline character `'\n'` instead. `std::endl` performs two operations: it writes a newline character to the output stream and then flushes the stream buffer, which can be less efficient than writing a single newline character using `'\n'`.
This fixes llvm#35321
Reviewed By: PiotrZSL
Differential Revision: https://reviews.llvm.org/D148318
Previously a struct like this:
template <typename>
struct A { A(A&&) = default; };
Would trigger a false positive, since even though it is not marked as
noexcept it still is due to the `= default`.
Now we only give a warning if the defaulted move constructor is
actually declared as throwing and correctly resolve it if they are
defaulted.
This fixes llvm#56026, llvm#41414, llvm#38081
Reviewed By: PiotrZSL
Differential Revision: https://reviews.llvm.org/D146922
In the following code:
```cc
struct Obj {
Obj();
Obj(const Obj &);
Obj(Obj &&);
virtual ~Obj();
};
Obj ConstNrvo() {
const Obj obj;
return obj;
}
```
performance-no-automatic-move warns about the constness of `obj`. However, NRVO
is applied to `obj`, so the `const` should have no effect on performance.
This change modifies the matcher to exclude NRVO variables.
#clang-tidy
Reviewed By: courbet, PiotrZSL
Differential Revision: https://reviews.llvm.org/D147419
We forgot to apply the change to headers in the previous patch,
due to missing "-header-filter" in the run-clang-tidy invocation.
Differential Revision: https://reviews.llvm.org/D142307
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
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
I went over the output of the following mess of a command:
`(ulimit -m 2000000; ulimit -v 2000000; git ls-files -z | parallel --xargs -0 cat | aspell list --mode=none --ignore-case | grep -E '^[A-Za-z][a-z]*$' | sort | uniq -c | sort -n | grep -vE '.{25}' | aspell pipe -W3 | grep : | cut -d' ' -f2 | less)`
and proceeded to spend a few days looking at it to find probable typos
and fixed a few hundred of them in all of the llvm project (note, the
ones I found are not anywhere near all of them, but it seems like a
good start).
Reviewed By: kadircet
Differential Revision: https://reviews.llvm.org/D130826
- Rename doc files to subdirs by module
- Update release notes and check list to use subdirs
- Update add_new_check.py to handle doc subdirs
Differential Revision: https://reviews.llvm.org/D126495
The checker missed a check for parameter type of primary template of specialization template and this could cause build breakages.
Reviewed By: aaron.ballman, flx
Differential Revision: https://reviews.llvm.org/D116593
