Commit Graph

2283 Commits

Author SHA1 Message Date
Kazu Hirata 4db2e4cebe Use {DenseSet,SetVector,SmallPtrSet}::contains (NFC) 2021-10-30 19:00:19 -07:00
Clement Courbet fc1b24d736 [clang-tidy]performance-unnecessary-copy-initialization: fix false negative
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
2021-10-29 08:41:03 +02:00
Salman Javed 897402e959 [clang-tidy] Correct typo in bugprone-easily-swappable-parameters
The string table `DefaultIgnoredParameterTypeSuffixes` has a typo:
`ForwardIt` is mistyped as `FowardIt`.

Correct typo and add test coverage.

Differential Revision: https://reviews.llvm.org/D112596
2021-10-27 22:38:52 +13:00
Carlos Galvez b43a2aee4e [clang-tidy] Suppress readability-static-access-through-instance for CUDA built-in variables
clang-tidy can be used to statically analyze CUDA code,
thanks to clang being able to compile CUDA code natively.
This makes clang-tidy the one and only open-source
static analyzer for CUDA.

However it currently warns for native CUDA built-in
variables, like threadIdx, due to the way they
are implemented in clang.

Users don't need to know the details of the clang
implementation, and they should continue to write
idiomatic code. Therefore, suppress the warning
if a CUDA built-in variable is encountered.

Fixes https://bugs.llvm.org/show_bug.cgi?id=48758
2021-10-26 05:45:25 +00:00
Carlos Galvez 7812cb72a3 Use reference type in for loop
To fix failing build job.
2021-10-19 16:37:56 +00:00
Carlos Galvez bf6b0d1674 [clang-tidy] Support globbing in NOLINT* expressions
To simplify suppressing warnings (for example, for
when multiple check aliases are enabled).

The globbing format reuses the same code as for
globbing when enabling checks, so the semantics
and behavior is identical.

Differential Revision: https://reviews.llvm.org/D111208
2021-10-19 16:30:51 +00:00
Carlos Galvez f0711106dc [clang-tidy] Fix false positive in cppcoreguidelines-virtual-class-destructor
Incorrectly triggers for template classes that inherit
from a base class that has virtual destructor.

Any class inheriting from a base that has a virtual destructor
will have their destructor also virtual, as per the Standard:

https://timsong-cpp.github.io/cppwp/n4140/class.dtor#9

> If a class has a base class with a virtual destructor,
> its destructor (whether user- or implicitly-declared) is virtual.

Added unit tests to prevent regression.

Fixes bug https://bugs.llvm.org/show_bug.cgi?id=51912

Differential Revision: https://reviews.llvm.org/D110614
2021-10-16 08:27:08 +00:00
liuke ea72b55b5c bugprone-argument-comment: SourceLocation valid judgment avoid emitting coredump in isInSystemHeader
If the Node has an invalid location, it will trigger assert in
isInSystemHeader(...).

void test() {
  __builtin_va_list __args;
  // __builtin_va_list has no defination in any source file and its
  // CXXConstructorDecl has invalid sourcelocation
}
coredump with "Assertion `Loc.isValid() && "Can't get file
characteristic of invalid loc!"' failed." in
getFileCharacteristic(SourceLocation).
2021-10-13 12:31:02 -04:00
Carlos Galvez 40546cb381 Remove 'IgnoreDestructors = true' from cppcoreguidelines-explicit-virtual-functions
This requirement was introduced in the C++ Core guidelines in 2016:

1894380d0a

Then clang-tidy got updated to comply with the rule.

However in 2019 this decision was reverted:

5fdfb20b76

Therefore we need to apply the correct configuration to
clang-tidy again.

This also makes this cppcoreguidelines check consistent
with the other 2 alias checks: hicpp-use-override and
modernize-use-override.

Additionally, add another RUN line to the unit test,
to make sure cppcoreguidelines-explicit-virtual-functions
is tested.
2021-10-12 10:08:08 -04:00
Matt Beardsley 32ab79ebc4 [clang-tidy] Fix add_new_check.py to generate correct list.rst autofix column from relative path
Previously, the code in add_new_check.py that looks for fixit keywords in check source files when generating list.rst assumed that the script would only be called from its own path. That means it doesn't find any source files for the checks it's attempting to scan for, and it defaults to writing out nothing in the "Offers fixes" column for all checks. Other parts of add_new_check.py work from other paths, just not this part.

After this fix, add_new_check.py's "offers fixes" column generation for list.rst will be consistent regardless of what path it's called from by using the caller path that's deduced elsewhere already from sys.argv[0].

Reviewed By: kbobyrev

Differential Revision: https://reviews.llvm.org/D110600
2021-10-05 18:09:53 +02:00
Jay Foad d933adeaca [APInt] Stop using soft-deprecated constructors and methods in clang. NFC.
Stop using APInt constructors and methods that were soft-deprecated in
D109483. This fixes all the uses I found in clang.

Differential Revision: https://reviews.llvm.org/D110808
2021-10-04 09:38:11 +01:00
Simon Pilgrim 7674bd4d44 [clang-tidy] Merges separate isa<>/assert/unreachable/dyn_cast<>/cast<> calls
We can directly use cast<> instead of separate dyn_cast<> with assertions as cast<> will perform this for us.

Similarly we can replace a if(isa<>)+cast<>/dyn_cast<> with if(dyn_cast<>)
2021-09-29 16:35:29 +01:00
Salman Javed 722e705f72 Revert 9b944c1843 with fixes
This reintroduces c0687e1984 (Add support
for `NOLINTBEGIN` ... `NOLINTEND` comments) but with fixes to the tests.
2021-09-29 08:00:45 -04:00
Nico Weber 5cf0606140 [clang] Let PPCallbacks::PragmaWarning() pass specifier as enum instead of string
Differential Revision: https://reviews.llvm.org/D110635
2021-09-28 19:47:27 -04:00
Aaron Ballman 9b944c1843 Revert "Add support for `NOLINTBEGIN` ... `NOLINTEND` comments"
This reverts commit c0687e1984.

There are testing failures being caught by bots.
See http://45.33.8.238/linux/56886/step_8.txt as an example.
2021-09-28 14:49:27 -04:00
Salman Javed c0687e1984 Add support for `NOLINTBEGIN` ... `NOLINTEND` comments
Add support for NOLINTBEGIN ... NOLINTEND comments to suppress
clang-tidy warnings over multiple lines. All lines between the "begin"
and "end" markers are suppressed.

Example:

// NOLINTBEGIN(some-check)
<Code with warnings to be suppressed, line 1>
<Code with warnings to be suppressed, line 2>
<Code with warnings to be suppressed, line 3>
// NOLINTEND(some-check)
Follows similar syntax as the NOLINT and NOLINTNEXTLINE comments
that are already implemented, i.e. allows multiple checks to be provided
in parentheses; suppresses all checks if the parentheses are omitted,
etc.

If the comments are misused, e.g. using a NOLINTBEGIN but not
terminating it with a NOLINTEND, a clang-tidy-nolint diagnostic
message pointing to the misuse is generated.

As part of implementing this feature, the following bugs were fixed in
existing code:

IsNOLINTFound(): IsNOLINTFound("NOLINT", Str) returns true when Str is
"NOLINTNEXTLINE". This is because the textual search finds NOLINT as
the stem of NOLINTNEXTLINE.

LineIsMarkedWithNOLINT(): NOLINTNEXTLINEs on the very first line of a
file are ignored. This is due to rsplit('\n\').second returning a blank
string when there are no more newline chars to split on.
2021-09-28 07:53:23 -04:00
Aaron Ballman ef0f728abe Add a missing include to appease the build bots 2021-09-27 14:19:39 -04:00
Carlos Galvez b2a2c38349 Fix bug in readability-uppercase-literal-suffix
Fixes https://bugs.llvm.org/show_bug.cgi?id=51790. The check triggers
incorrectly with non-type template parameters.

A bisect determined that the bug was introduced here:
ea2225a10b

Unfortunately that patch can no longer be reverted on top of the main
branch, so add a fix instead. Add a unit test to avoid regression in
the future.
2021-09-27 14:03:53 -04:00
liuke e4902480f1 Fix wrong FixIt about union in cppcoreguidelines-pro-type-member-init
At most one variant member of a union may have a default member
initializer. The case of anonymous records with multiple levels of
nesting like the following also needs to meet this rule. The original
logic is to horizontally obtain all the member variables in a record
that need to be initialized and then filter to the variables that need
to be fixed. Obviously, it is impossible to correctly initialize the
desired variables according to the nesting relationship.

See Example 3 in class.union

union U {
  U() {}
  int x;  // int x{};
  union {
    int k;  // int k{};  <==  wrong fix
  };
  union {
    int z;  // int z{};  <== wrong fix
    int y;
  };
};
2021-09-24 13:15:21 -04:00
Saleem Abdulrasool d249200fa7 Revert "Re-Revert "clang-tidy: introduce readability-containter-data-pointer check""
This reverts commit 626586fc25.

Tweak the test for Windows.  Windows defaults to delayed template
parsing, which resulted in the main template definition not registering
the test on Windows.  Process the file with the additional
`-fno-delayed-template-parsing` flag to change the default beahviour.
Additionally, add an extra check for the fix it and use a more robust
test to ensure that the value is always evaluated.

Differential Revision: https://reviews.llvm.org/D108893
2021-09-15 20:52:55 +00:00
Nico Weber 626586fc25 Re-Revert "clang-tidy: introduce readability-containter-data-pointer check"
This reverts commit 49992c0414.
The test is still failing on Windows, see comments on https://reviews.llvm.org/D108893
2021-09-14 22:27:59 -04:00
Saleem Abdulrasool 49992c0414 Revert "Revert "clang-tidy: introduce readability-containter-data-pointer check""
This reverts commit 76dc8ac36d.

Restore the change.  The test had an incorrect negative from testing.
The test is expected to trigger a failure as mentioned in the review
comments.  This corrects the test and should resolve the failure.
2021-09-14 10:52:35 -07:00
Nico Weber 76dc8ac36d Revert "clang-tidy: introduce readability-containter-data-pointer check"
This reverts commit d0d9e6f084.
Breaks tests, see e.g. https://lab.llvm.org/buildbot/#/builders/188/builds/3326
2021-09-14 12:37:10 -04:00
Saleem Abdulrasool d0d9e6f084 clang-tidy: introduce readability-containter-data-pointer check
This introduces a new check, readability-containter-data-pointer.  This
check is meant to catch the cases where the user may be trying to
materialize the data pointer by taking the address of the 0-th member of
a container.  With C++11 or newer, the `data` member should be used for
this.  This provides the following benefits:

- `.data()` is easier to read than `&[0]`
- it avoids an unnecessary re-materialization of the pointer
  * this doesn't matter in the case of optimized code, but in the case
    of unoptimized code, this will be visible
- it avoids a potential invalid memory de-reference caused by the
  indexing when the container is empty (in debug mode, clang will
  normally optimize away the re-materialization in optimized builds).

The small potential behavioural change raises the question of where the
check should belong.  A reasoning of defense in depth applies here, and
this does an unchecked conversion, with the assumption that users can
use the static analyzer to catch cases where we can statically identify
an invalid memory de-reference.  For the cases where the static analysis
is unable to prove the size of the container, UBSan can be used to track
the invalid access.

Special thanks to Aaron Ballmann for the discussion on whether this
check would be useful and where to place it.

This also partially resolves PR26817!

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D108893
2021-09-14 08:12:10 -07:00
Corentin Jabot 601102d282 Cleanup identifier parsing; NFC
Rename methods to clearly signal when they only deal with ASCII,
simplify the parsing of identifier, and use start/continue instead of
head/body for consistency with Unicode terminology.
2021-09-14 09:12:22 -04:00
Matt Beardsley c6bf8b8592 Fix python 2-vs-3 issues in add_new_check.py and rename_check.py
As of this commit:
  https://github.com/llvm/llvm-project/commit/307b1fdd

If either of those scripts are invoked with python 2, neither works due to:
  "TypeError: write() argument 1 must be unicode, not str"

And if rename_check.py is invoked with python 3:
  "ValueError: binary mode doesn't take an encoding argument"
(referring to `with io.open(filename, 'wb', encoding='utf8') as f:`), and

Another issue in rename_check.py in python 2:
  "TypeError: list object is not an iterator"
(referring to `next(filter( ... os.listdir(old_module_path)))`)

(so, rename_check doesn't work with either 2 or 3, and add_new_check
doesn't work with 2, but does work with 3)

I ran these steps to test both python versions:
(manually - appears to be the "status quo" for these files)

  python3 clang-tools-extra/clang-tidy/add_new_check.py readability ggggg
  python3 clang-tools-extra/clang-tidy/rename_check.py readability-ggggg readability-hhhhh

  git checkout HEAD -- clang-tools-extra/clang-tidy/readability/CMakeLists.txt clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp clang-tools-extra/docs/ReleaseNotes.rst clang-tools-extra/docs/clang-tidy/checks/list.rst
  rm -f clang-tools-extra/clang-tidy/readability/GggggCheck.cpp clang-tools-extra/clang-tidy/readability/GggggCheck.h clang-tools-extra/docs/clang-tidy/checks/readability-ggggg.rst clang-tools-extra/test/clang-tidy/checkers/readability-ggggg.cpp clang-tools-extra/clang-tidy/readability/HhhhhCheck.cpp clang-tools-extra/clang-tidy/readability/HhhhhCheck.h clang-tools-extra/docs/clang-tidy/checks/readability-hhhhh.rst

  python2 clang-tools-extra/clang-tidy/add_new_check.py readability ggggg
  python2 clang-tools-extra/clang-tidy/rename_check.py readability-ggggg readability-hhhhh

  git checkout HEAD -- clang-tools-extra/clang-tidy/readability/CMakeLists.txt clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp clang-tools-extra/docs/ReleaseNotes.rst clang-tools-extra/docs/clang-tidy/checks/list.rst
  rm -f clang-tools-extra/clang-tidy/readability/GggggCheck.cpp clang-tools-extra/clang-tidy/readability/GggggCheck.h clang-tools-extra/docs/clang-tidy/checks/readability-ggggg.rst clang-tools-extra/test/clang-tidy/checkers/readability-ggggg.cpp clang-tools-extra/clang-tidy/readability/HhhhhCheck.cpp clang-tools-extra/clang-tidy/readability/HhhhhCheck.h clang-tools-extra/docs/clang-tidy/checks/readability-hhhhh.rst

Reviewed By: kbobyrev

Differential Revision: https://reviews.llvm.org/D109127
2021-09-11 09:52:50 +02:00
Nilay Vaish e976fc61ec Add "profiling" to the list of absl libraries.
Reviewed By: ymandel

Differential Revision: https://reviews.llvm.org/D109470
2021-09-09 20:31:06 +00:00
Marco Gartmann c58c7a6ea0 [clang-tidy] cppcoreguidelines-virtual-base-class-destructor: a new check
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
2021-09-09 13:23:38 +02:00
Artem Dergachev dcde8fdeeb [clang-tidy] bugprone-infinite-loop: Fix false positives with volatile addresses.
Low-level code may occasionally deal with direct access by concrete addresses
such as 0x1234. Values at these addresses act like globals: they can change
at any time. They typically wear volatile qualifiers.

Suppress all warnings on loops with conditions that involve casting anything to
a pointer-to-...-pointer-to-volatile type.

The closely related bugprone-redundant-branch-condition check
doesn't seem to be affected. Add a test just in case.

Differential Revision: https://reviews.llvm.org/D108808
2021-09-07 15:10:46 -07:00
Kazu Hirata dfc46f0268 [clang-tidy] Drop unnecessary const from return types (NFC)
Identified with readability-const-return-type.
2021-09-05 08:37:27 -07:00
Gabor Bencze 3373e84539 [clang-tidy] Add bugprone-suspicious-memory-comparison check
The check warns on suspicious calls to `memcmp`.
It currently checks for comparing types that do not have
unique object representations or are non-standard-layout.
Based on
  https://wiki.sei.cmu.edu/confluence/display/c/EXP42-C.+Do+not+compare+padding+data
  https://wiki.sei.cmu.edu/confluence/display/c/FLP37-C.+Do+not+use+object+representations+to+compare+floating-point+values
and part of
  https://wiki.sei.cmu.edu/confluence/display/cplusplus/OOP57-CPP.+Prefer+special+member+functions+and+overloaded+operators+to+C+Standard+Library+functions
Add alias `cert-exp42-c` and `cert-flp37-c`.

Some tests are currently failing at head, the check depends on D89649.
Originally started in D71973

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D89651
2021-08-26 09:23:37 +02:00
Whisperity 8d50a847d4 [clang-tidy] Hotfix default parameter value in 'bugprone-easily-swappable-parameters'
As identified by @RKSimon, there was a missing comma in the default
value for the "ignored parameter type suffixes" array, resulting in
bogus concatenation of two elements.
2021-08-24 16:10:19 +02:00
mydeveloperday fe866327c1 [clang-tidy] [PR50069] readability-braces-around-statements doesn't work well with [[likely]] [[unlikely]]
https://bugs.llvm.org/show_bug.cgi?id=50069

When clang-tidy sees:

```
if (true) [[unlikely]] {
    ...
}
```

It thinks the braces are missing and add them again.

```
if (true)  { [[unlikely]] {
    ...
  }
}
```

This revision aims to prevent that incorrect code generation

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D105479
2021-08-14 12:05:21 +01:00
liuke 1f2d40c47f [clang-tidy] fix duplicate '{}' in cppcoreguidelines-pro-type-member-init
The overload of the constructor will repeatedly fix the member variables that need to be initialized.
Removed the duplicate '{}'.

```
struct A {
  A() {}
  A(int) {}
  int _var;  // int _var{}{};  <--  wrong fix
};
```

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D107641
2021-08-14 10:48:04 +08:00
Florin Iucha d2c5cbc3a8 Add a check for enforcing minimum length for variable names
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.
2021-08-12 11:31:26 -04:00
Christopher Di Bella c874dd5362 [llvm][clang][NFC] updates inline licence info
Some files still contained the old University of Illinois Open Source
Licence header. This patch replaces that with the Apache 2 with LLVM
Exception licence.

Differential Revision: https://reviews.llvm.org/D107528
2021-08-11 02:48:53 +00:00
Tom Lokovic 1fdb3e36ff abseil-string-find-str-contains should not propose an edit for the three-parameter version of find().
std::string, std::string_view, and absl::string_view all have a three-parameter version of find()
which has a "count" (or "n") paremeter limiting the size of the substring to search.  We don't want
to propose changing to absl::StrContains in those cases.  This change fixes that and adds unit tests
to confirm.

Reviewed By: ymandel

Differential Revision: https://reviews.llvm.org/D107837
2021-08-10 16:39:17 +00:00
Sam McCall c8f148274f Reapply "Support Attr in DynTypedNode and ASTMatchers."
This reverts commit 3241680f11.
Fixed mangled post-test formatting :-(
2021-08-06 22:30:32 +02:00
Sam McCall 3241680f11 Revert "Support Attr in DynTypedNode and ASTMatchers."
This reverts commit a4bdcdadc6.

Fails bots:
https://lab.llvm.org/buildbot/#/builders/109/builds/20231/steps/6/logs/stdio
2021-08-06 22:27:54 +02:00
Sam McCall a4bdcdadc6 Support Attr in DynTypedNode and ASTMatchers.
Differential Revision: https://reviews.llvm.org/D89743
2021-08-06 22:06:04 +02:00
Douglas Chen 559d142331 [clang-tidy] Fix command line is too long issue which breaks test on Windows
This patch tries to fix command line too long problem on Windows for
https://reviews.llvm.org/D86671.

The command line is too long with check_clang_tidy.py program on Windows,
because the configuration is long for regression test. Fix this issue by
passing the settings in file instead.

Differential Revision: https://reviews.llvm.org/D107325
2021-08-03 22:12:46 +02:00
George Burgess IV 2e75986a21 bugprone-argument-comment: ignore mismatches from system headers
As of 2a3498e24f, we ignore parameter name mismatches for functions
in the `std::` namespace, since those aren't standardized. It seems
reasonable to extend this to all functions which are declared in system
headers, since this lint can be a bit noisy otherwise
(https://bugs.chromium.org/p/chromium/issues/detail?id=1191507).

Differential Revision: https://reviews.llvm.org/D99993
2021-08-03 19:56:27 +00:00
Andy Yankovsky 307b1fddd4 [clang-tidy] Always open files using UTF-8 encoding
The encoding used for opening files depends on the OS and might be different
from UTF-8 (e.g. on Windows it can be CP-1252). The documentation files use
UTF-8 and might be incompatible with other encodings. For example, right now
`clang-tools-extra/docs/clang-tidy/checks/abseil-no-internal-dependencies.rst`
has non-ASCII quotes and running `add_new_check.py` fails on Windows, because
it tries to read the file with incompatible encoding.

Use `io.open` for compatibility with both Python 2 and Python 3.

Reviewed By: kbobyrev

Differential Revision: https://reviews.llvm.org/D106792
2021-08-02 11:36:04 +02:00
Douglas Chen 2b9b5bc040 [clang-tidy] Add new case type to check variables with Hungarian notation
Add IdentifierNamingCheck::CaseType, CT_HungarianNotation, supporting
naming check with Hungarian notation.

Differential Revision: https://reviews.llvm.org/D86671
2021-08-01 15:22:17 -07:00
Liuke Gehry 4a097efe77 [clang-tidy] Fix cppcoreguidelines-init-variables by removing the enum
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
2021-07-30 18:24:47 +02:00
Jesse Towner 68546c9d6f bugprone-forwarding-reference-overload: support non-type template parameters
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.
2021-07-29 07:01:19 -04:00
Whisperity 21832121e1 [clang-tidy] Fix crash on "reference-to-array" parameters in 'bugprone-easily-swappable-parameters'
An otherwise unexercised code path related to trying to model
"array-to-pointer decay" resulted in a null pointer dereference crash
when parameters of type "reference to array" were encountered.

Fixes crash report http://bugs.llvm.org/show_bug.cgi?id=50995.

Reviewed By: aaron.ballman

Differential Revision: http://reviews.llvm.org/D106946
2021-07-28 14:44:20 +02:00
Whisperity 8b0cc4a65d [clang-tidy] Improve "common type" diagnostic output in 'bugprone-easily-swappable-parameters'
Make the check handle cases of the "common type" involved in the mix
being non-trivial, e.g. pointers, references, attributes, these things
coming from typedefs, etc.

This results in clearer diagnostics that have more coverage in their
explanation, such as saying `const int &` as common type instead of
`int`.

Reviewed By: aaron.ballman

Differential Revision: http://reviews.llvm.org/D106442
2021-07-23 10:26:22 +02:00
Felix Berger cb4c12b611 [clang-tidy] performance-unnecessary-copy-initialization: Create option to exclude container types from triggering the check.
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
2021-07-22 16:20:20 -04:00
Felix Berger 00edae9203 [clang-tidy] performance-unnecessary-copy-initialization: Disable check when variable and initializer have different replaced template param types.
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
2021-07-22 15:17:24 -04:00