Extra Clang Tools 10.0.0 Release Notes — Extra Clang Tools 10 documentation

# Extra Clang Tools 10 documentation

## Extra Clang Tools 10.0.0 Release Notes

- Introduction

- What’s New in Extra Clang Tools 10.0.0?

  - Improvements to clangd

  - Improvements to clang-doc

  - Improvements to clang-tidy

    - New checks

    - New aliases

    - Changes in existing checks

    - Renamed checks

  - Clang-tidy visual studio plugin

Written by the LLVM Team

## Introduction

This document contains the release notes for the Extra Clang Tools, part of the Clang release 10.0.0. Here we describe the status of the Extra Clang Tools in some detail, including major improvements from the previous release and new feature work. All LLVM releases may be downloaded from the LLVM releases web site.

For more information about Clang or LLVM, including information about the latest release, please see the Clang Web Site or the LLVM Web Site.

## What’s New in Extra Clang Tools 10.0.0?

Some of the major new features and improvements to Extra Clang Tools are listed here. Generic improvements to Extra Clang Tools as a whole or to its underlying infrastructure are described first, followed by tool-specific sections.

### Improvements to clangd

- clangd documentation is now found at https://clangd.llvm.org/

- Go-to-definition, hover, find-references etc use a new mechanism to identify what is under the cursor, which is (hopefully) more consistent and accurate.

- clangd should be able to reliably locate the standard library/SDK on macOS.

- Shutdown more cleanly on receiving a signal. In particular temporary PCH files should be cleaned up.

- Find references now works on macros.

- clangd can be more easily used remotely or in a docker container.

  The `--path-mappings` flag translates between local and remote paths.

- Experimental support for renaming across files (behind the `--cross-file-rename` flag).

- Hover now exposes more information, including the type of symbols and the value of constant expressions.

- Go to definition now works in dependent code in more cases, by assuming the primary template is used.

- Better recovery and reporting when the compile command for a file can’t be fully parsed.

- Switch header/source (an extension) now uses index information in addition to filename heuristics, and is much more robust.

- Semantic selection (expand/contract selection) is supported.

- Semantic highlighting is more robust, highlights more types of tokens, and as an extension provides information about inactive preprocessor regions.

- Code completion results now include an extension field `score`.

  This allows clients to incorporate clangd quality signals when re-ranking code completion after client-side fuzzy-matching.

- New refactorings: define function out-of-line, define function in-line, extract function, remove using namespace directive, localize Objective-C string.

- Bug fixes and performance improvements :-)

### Improvements to clang-doc

- clang-doc now generates documentation in HTML format.

### Improvements to clang-tidy

#### New checks

- New bugprone-bad-signal-to-kill-thread check.

  Finds `pthread_kill` function calls when a thread is terminated by raising `SIGTERM` signal.

- New bugprone-dynamic-static-initializers check.

  Finds instances where variables with static storage are initialized dynamically in header files.

- New bugprone-infinite-loop check.

  Finds obvious infinite loops (loops where the condition variable is not changed at all).

- New bugprone-not-null-terminated-result check

  Finds function calls where it is possible to cause a not null-terminated result.

- New bugprone-signed-char-misuse check.

  Finds `signed char` to integer conversions which might indicate a programming error.

- New cert-mem57-cpp check.

  Checks if an object of type with extended alignment is allocated by using the default `operator new`.

- New cert-oop58-cpp check.

  Finds assignments to the copied object and its direct or indirect members in copy constructors and copy assignment operators.

- New cppcoreguidelines-init-variables check.

  Checks whether there are local variables that are declared without an initial value.

- New darwin-dispatch-once-nonstatic check.

  Finds declarations of `dispatch_once_t` variables without static or global storage.

- New google-upgrade-googletest-case check.

  Finds uses of deprecated Googletest APIs with names containing `case` and replaces them with equivalent APIs with `suite`.

- New linuxkernel-must-use-errs check.

  Checks Linux kernel code to see if it uses the results from the functions in `linux/err.h`.

- New llvm-prefer-register-over-unsigned check.

  Finds historical use of `unsigned` to hold vregs and physregs and rewrites them to use `Register`

- New objc-missing-hash check.

  Finds Objective-C implementations that implement `-isEqual:` without also appropriately implementing `-hash`.

- New performance-no-automatic-move check.

  Finds local variables that cannot be automatically moved due to constness.

- New performance-trivially-destructible check.

  Finds types that could be made trivially-destructible by removing out-of-line defaulted destructor declarations.

- New readability-make-member-function-const check.

  Finds non-static member functions that can be made `const` because the functions don’t use `this` in a non-const way.

- New readability-qualified-auto check.

  Adds pointer and `const` qualifications to `auto`-typed variables that are deduced to pointers and `const` pointers.

- New readability-redundant-access-specifiers check.

  Finds classes, structs, and unions that contain redundant member access specifiers.

#### New aliases

- New alias cert-pos44-c to bugprone-bad-signal-to-kill-thread was added.

- New alias llvm-qualified-auto to readability-qualified-auto was added.

#### Changes in existing checks

- Improved bugprone-posix-return check.

  Now also checks if any calls to `pthread_*` functions expect negative return values.

- Improved hicpp-signed-bitwise check.

  The check now supports the IgnorePositiveIntegerLiterals option.

- Improved modernize-avoid-bind check.

  The check now supports supports diagnosing and fixing arbitrary callables instead of only simple free functions. The PermissiveParameterList option has also been added to address situations where the existing fix-it logic would sometimes generate code that no longer compiles.

- The modernize-use-equals-default fix no longer adds semicolons where they would be redundant.

- Improved modernize-use-override check.

  The check now supports the AllowOverrideAndFinal option to eliminate conflicts with gcc -Wsuggest-override or gcc -Werror=suggest-override.

- The modernize-use-using check now converts typedefs containing struct definitions and multiple comma-separated types.

- Improved readability-magic-numbers check.

  The check now supports the IgnoreBitFieldsWidths option to suppress the warning for numbers used to specify bit field widths.

  The check was updated to eliminate some false positives (such as using class enumeration as non-type template parameters, or the synthetically computed length of a static user string literal.)

- Improved readability-redundant-member-init check.

  The check now supports the IgnoreBaseInCopyConstructors option to avoid “base class ‘Foo’ should be explicitly initialized in the copy constructor” warnings or errors with gcc -Wextra or gcc -Werror=extra.

- The readability-redundant-string-init check now supports a StringNames option enabling its application to custom string classes.

#### Renamed checks

- The ‘objc-avoid-spinlock’ check was renamed to darwin-avoid-spinlock

### Clang-tidy visual studio plugin

The clang-tidy-vs plugin has been removed from clang, as it’s no longer maintained. Users should migrate to Clang Power Tools instead.