[clang-tidy] Add performance-enum-size check

Finds enum type definitions that could use smaller integral type as a base.

Reviewed By: xgupta

Differential Revision: https://reviews.llvm.org/D144135

[clang-tidy] Add more checks for functions which should be noexcept

Added new checks
- `performance-noexcept-destructor`
- `performance-noexcept-swap`

Also added cppcoreguidlines aliases for the 2

[clang-tidy] Add more checks for functions which should be noexcept

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

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[clang-tidy] Add `performance-avoid-endl` check

This check flags uses of `std::endl` on streams and suggests using the newline character `'\n'` instead. `std::endl` performs two operations: it write

[clang-tidy] Add `performance-avoid-endl` check

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

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[clang-tidy][NFC] Use C++17 nested namespaces in the clang-tidy folder

Fix applied by running:

run-clang-tidy.py -checks=-*,modernize-concat-nested-namespaces

Differential Revision: https://review

[clang-tidy][NFC] Use C++17 nested namespaces in the clang-tidy folder

Fix applied by running:

run-clang-tidy.py -checks=-*,modernize-concat-nested-namespaces

Differential Revision: https://reviews.llvm.org/D141770

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[clang-tidy] Introduce misc No Integer To Pointer Cast check

While casting an (integral) pointer to an integer is obvious - you just get
the integral value of the pointer, casting an integer to an (

[clang-tidy] Introduce misc No Integer To Pointer Cast check

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

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[clang-tidy] new performance-no-automatic-move check.

Summary: The check flags constructs that prevent automatic move of local variables.

Reviewers: aaron.ballman

Subscribers: mgorny, xazax.hun, c

[clang-tidy] new performance-no-automatic-move check.

Summary: The check flags constructs that prevent automatic move of local variables.

Reviewers: aaron.ballman

Subscribers: mgorny, xazax.hun, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70390

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[clang-tidy] New checker performance-trivially-destructible-check

Checks for types which can be made trivially-destructible by removing
out-of-line defaulted destructor declarations.

The check is m

[clang-tidy] New checker performance-trivially-destructible-check

Checks for types which can be made trivially-destructible by removing
out-of-line defaulted destructor declarations.

The check is motivated by the work on C++ garbage collector in Blink
(rendering engine for Chrome), which strives to minimize destructors and
improve runtime of sweeping phase.

In the entire chromium codebase the check hits over 2000 times.

Differential Revision: https://reviews.llvm.org/D69435

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Fix file headers. NFC

llvm-svn: 355188

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
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

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[clang-tidy] Move more checks from misc- to performance-

Summary:
rename_check.py misc-move-const-arg performance-move-const-arg
rename_check.py misc-noexcept-move-constructor performance-noexcept-m

[clang-tidy] Move more checks from misc- to performance-

Summary:
rename_check.py misc-move-const-arg performance-move-const-arg
rename_check.py misc-noexcept-move-constructor performance-noexcept-move-constructor

Reviewers: hokein, xazax.hun

Reviewed By: xazax.hun

Subscribers: rnkovacs, klimek, mgorny, xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D40507

llvm-svn: 319183

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[clang-tidy] Move checks from misc- to performance-

Summary:
rename_check.py misc-move-constructor-init performance-move-constructor-init
rename_check.py misc-inefficient-algorithm performance-ineff

[clang-tidy] Move checks from misc- to performance-

Summary:
rename_check.py misc-move-constructor-init performance-move-constructor-init
rename_check.py misc-inefficient-algorithm performance-inefficient-algorithm

Reviewers: hokein, aaron.ballman

Reviewed By: hokein, aaron.ballman

Subscribers: aaron.ballman, mgorny, xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D40487

llvm-svn: 319023

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[clang-tidy] 'implicit cast' -> 'implicit conversion'

Summary:
This patch renames checks, check options and changes messages to use correct
term "implicit conversion" instead of "implicit cast" (whi

[clang-tidy] 'implicit cast' -> 'implicit conversion'

Summary:
This patch renames checks, check options and changes messages to use correct
term "implicit conversion" instead of "implicit cast" (which has been in use in
Clang AST since ~10 years, but it's still technically incorrect w.r.t. C++
standard).

* performance-implicit-cast-in-loop -> performance-implicit-conversion-in-loop
* readability-implicit-bool-cast -> readability-implicit-bool-conversion
- readability-implicit-bool-cast.AllowConditionalIntegerCasts ->
readability-implicit-bool-conversion.AllowIntegerConditions
- readability-implicit-bool-cast.AllowConditionalPointerCasts ->
readability-implicit-bool-conversion.AllowPointerConditions

Reviewers: hokein, jdennett

Reviewed By: hokein

Subscribers: mgorny, JDevlieghere, xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D36456

llvm-svn: 310366

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[clang-tidy] Add a clang-tidy check for possible inefficient vector operations

Summary:
The "performance-inefficient-vector-operation" check finds vector oprations in
for-loop statements which may c

[clang-tidy] Add a clang-tidy check for possible inefficient vector operations

Summary:
The "performance-inefficient-vector-operation" check finds vector oprations in
for-loop statements which may cause multiple memory reallocations.

This is the first version, only detects typical for-loop:

```
std::vector<int> v;
for (int i = 0; i < n; ++i) {
v.push_back(i);
}

// or

for (int i = 0; i < v2.size(); ++i) {
v.push_back(v2[i]);
}
```

We can extend it to handle more cases like for-range loop in the future.

Reviewers: alexfh, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: zaks.anna, Eugene.Zelenko, mgorny, cfe-commits, djasper

Differential Revision: https://reviews.llvm.org/D31757

llvm-svn: 300534

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[ClangTidy] Add new performance-type-promotion-in-math-fn check.

Summary:
This checks for calls to double-precision math.h with single-precision
arguments. For example, it suggests replacing ::sin(

[ClangTidy] Add new performance-type-promotion-in-math-fn check.

Summary:
This checks for calls to double-precision math.h with single-precision
arguments. For example, it suggests replacing ::sin(0.f) with
::sinf(0.f).

Subscribers: mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D27284

llvm-svn: 289627

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[clang-tidy] Inefficient string operation

Patch by Bittner Barni!

Differential revision: https://reviews.llvm.org/D20196

llvm-svn: 277677

[clang-tidy] Add performance check to flag function parameters of expensive to copy types that can be safely converted to const references.

Reviewers: alexfh

Subscribers: fowles, cfe-commits

Diffe

[clang-tidy] Add performance check to flag function parameters of expensive to copy types that can be safely converted to const references.

Reviewers: alexfh

Subscribers: fowles, cfe-commits

Differential Revision: http://reviews.llvm.org/D17491

llvm-svn: 264694

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[clang-tidy] Add check performance-faster-string-find

Summary:
Add check performance-faster-string-find.
It replaces single character string literals to character literals in calls to string::find a

[clang-tidy] Add check performance-faster-string-find

Summary:
Add check performance-faster-string-find.
It replaces single character string literals to character literals in calls to string::find and friends.

Reviewers: alexfh

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D16152

llvm-svn: 260712

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[clang-tidy] ForRangeCopyCheck that warns on and fixes unnecessary copies of loop variables.

Patch by Felix Berger!

Differential revision: http://reviews.llvm.org/D13849

llvm-svn: 259199

[clang-tidy] Move implicit-cast-in-loop check to upstream.

Summary: This is implemented originally by Alex Pilkiewicz (pilki@google.com).

Reviewers: alexfh

Subscribers: cfe-commits

Patch by Haoji

[clang-tidy] Move implicit-cast-in-loop check to upstream.

Summary: This is implemented originally by Alex Pilkiewicz (pilki@google.com).

Reviewers: alexfh

Subscribers: cfe-commits

Patch by Haojian Wu!

Differential Revision: http://reviews.llvm.org/D16721

llvm-svn: 259195

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[clang-tidy] Add UnnecessaryCopyInitialization check to new "performance" module in ClangTidy

Summary:
The patch adds a new ClangTidy check that detects when expensive-to-copy types are unnecessaril

[clang-tidy] Add UnnecessaryCopyInitialization check to new "performance" module in ClangTidy

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

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