Clang 9.0.0 (In-Progress) Release Notes¶
- Introduction
- What’s New in Clang 9.0.0?
- Major New Features
- Non-comprehensive list of changes in this release
- New Compiler Flags
- Deprecated Compiler Flags
- Modified Compiler Flags
- New Pragmas in Clang
- Attribute Changes in Clang
- Windows Support
- C Language Changes in Clang
- C++ Language Changes in Clang
- Objective-C Language Changes in Clang
- OpenCL C Language Changes in Clang
- ABI Changes in Clang
- OpenMP Support in Clang
- CUDA Support in Clang
- Internal API Changes
- AST Matchers
- clang-format
- libclang
- Static Analyzer
- Undefined Behavior Sanitizer (UBSan)
- Core Analysis Improvements
- New Issues Found
- Significant Known Problems
- Additional Information
Written by the LLVM Team
Warning
These are in-progress notes for the upcoming Clang 9 release. Release notes for previous releases can be found on the Download Page.
Introduction¶
This document contains the release notes for the Clang C/C++/Objective-C frontend, part of the LLVM Compiler Infrastructure, release 9.0.0. Here we describe the status of Clang in some detail, including major improvements from the previous release and new feature work. For the general LLVM release notes, see the LLVM documentation. 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.
Note that if you are reading this file from a Subversion checkout or the main Clang web page, this document applies to the next release, not the current one. To see the release notes for a specific release, please see the releases page.
What’s New in Clang 9.0.0?¶
Some of the major new features and improvements to Clang are listed here. Generic improvements to Clang as a whole or to its underlying infrastructure are described first, followed by language-specific sections with improvements to Clang’s support for those languages.
Deprecated Compiler Flags¶
The following options are deprecated and ignored. They will be removed in future versions of Clang.
- …
OpenMP Support in Clang¶
- OpenMP 5.0 features
- Support relational-op != (not-equal) as one of the canonical forms of random access iterator.
- Added support for mapping of the lambdas in target regions.
- Added parsing/sema analysis for the requires directive.
- Support nested declare target directives.
- Make the this pointer implicitly mapped as map(this[:1]).
- Added the close map-type-modifier.
- Various bugfixes and improvements.
New features supported for Cuda devices:
- Added support for the reductions across the teams.
- Extended number of constructs that can be executed in SPMD mode.
- Fixed support for lastprivate/reduction variables in SPMD constructs.
- New collapse clause scheme to avoid expensive remainder operations.
- New default schedule for distribute and parallel constructs.
- Simplified code generation for distribute and parallel in SPMD mode.
- Flag (
-fopenmp_optimistic_collapse) for user to limit collapsed loop counter width when safe to do so. - General performance improvement.
Internal API Changes¶
These are major API changes that have happened since the 8.0.0 release of Clang. If upgrading an external codebase that uses Clang as a library, this section should help get you past the largest hurdles of upgrading.
- …
Additional Information¶
A wide variety of additional information is available on the Clang web
page. The web page contains versions of the
API documentation which are up-to-date with the Subversion version of
the source code. You can access versions of these documents specific to
this release by going into the “clang/docs/” directory in the Clang
tree.
If you have any questions or comments about Clang, please feel free to contact us via the mailing list.