forked from OSchip/llvm-project
248 lines
6.6 KiB
ReStructuredText
248 lines
6.6 KiB
ReStructuredText
=======================================
|
|
Clang 7.0.0 (In-Progress) Release Notes
|
|
=======================================
|
|
|
|
.. contents::
|
|
:local:
|
|
:depth: 2
|
|
|
|
Written by the `LLVM Team <http://llvm.org/>`_
|
|
|
|
.. warning::
|
|
|
|
These are in-progress notes for the upcoming Clang 7 release.
|
|
Release notes for previous releases can be found on
|
|
`the Download Page <http://releases.llvm.org/download.html>`_.
|
|
|
|
Introduction
|
|
============
|
|
|
|
This document contains the release notes for the Clang C/C++/Objective-C
|
|
frontend, part of the LLVM Compiler Infrastructure, release 7.0.0. 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 <http://llvm.org/docs/ReleaseNotes.html>`_. All LLVM
|
|
releases may be downloaded from the `LLVM releases web
|
|
site <http://llvm.org/releases/>`_.
|
|
|
|
For more information about Clang or LLVM, including information about the
|
|
latest release, please see the `Clang Web Site <http://clang.llvm.org>`_ or the
|
|
`LLVM Web Site <http://llvm.org>`_.
|
|
|
|
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 <http://llvm.org/releases/>`_.
|
|
|
|
What's New in Clang 7.0.0?
|
|
==========================
|
|
|
|
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.
|
|
|
|
Major New Features
|
|
------------------
|
|
|
|
- ...
|
|
|
|
Improvements to Clang's diagnostics
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
- ``-Wc++98-compat-extra-semi`` is a new flag, which was previously inseparable
|
|
from ``-Wc++98-compat-pedantic``. The latter still controls the new flag.
|
|
|
|
- ``-Wextra-semi`` now also controls ``-Wc++98-compat-extra-semi``.
|
|
Please do note that if you pass ``-Wno-c++98-compat-pedantic``, it implies
|
|
``-Wno-c++98-compat-extra-semi``, so if you want that diagnostic, you need
|
|
to explicitly re-enable it (e.g. by appending ``-Wextra-semi``).
|
|
|
|
- ``-Wself-assign`` and ``-Wself-assign-field`` were extended to diagnose
|
|
self-assignment operations using overloaded operators (i.e. classes).
|
|
If you are doing such an assignment intentionally, e.g. in a unit test for
|
|
a data structure, the warning can be suppressed by adding ``*&`` to the
|
|
right-hand side or casting it to the appropriate reference type.
|
|
|
|
Non-comprehensive list of changes in this release
|
|
-------------------------------------------------
|
|
|
|
- Clang binary and libraries have been renamed from 7.0 to 7.
|
|
For example, the ``clang`` binary will be called ``clang-7``
|
|
instead of ``clang-7.0``.
|
|
|
|
- Clang implements a collection of recent fixes to the C++ standard's definition
|
|
of "standard-layout". In particular, a class is only considered to be
|
|
standard-layout if all base classes and the first data member (or bit-field)
|
|
can be laid out at offset zero.
|
|
|
|
- ...
|
|
|
|
New Compiler Flags
|
|
------------------
|
|
|
|
- ...
|
|
|
|
Deprecated Compiler Flags
|
|
-------------------------
|
|
|
|
The following options are deprecated and ignored. They will be removed in
|
|
future versions of Clang.
|
|
|
|
- ...
|
|
|
|
Modified Compiler Flags
|
|
-----------------------
|
|
|
|
- Before Clang 7, we prepended the `#` character to the `--autocomplete`
|
|
argument to enable cc1 flags. For example, when the `-cc1` or `-Xclang` flag
|
|
is in the :program:`clang` invocation, the shell executed
|
|
`clang --autocomplete=#-<flag to be completed>`. Clang 7 now requires the
|
|
whole invocation including all flags to be passed to the `--autocomplete` like
|
|
this: `clang --autocomplete=-cc1,-xc++,-fsyn`.
|
|
|
|
New Pragmas in Clang
|
|
-----------------------
|
|
|
|
Clang now supports the ...
|
|
|
|
|
|
Attribute Changes in Clang
|
|
--------------------------
|
|
|
|
- Clang now supports function multiversioning with attribute 'target' on ELF
|
|
based x86/x86-64 environments by using indirect functions. This implementation
|
|
has a few minor limitations over the GCC implementation for the sake of AST
|
|
sanity, however it is otherwise compatible with existing code using this
|
|
feature for GCC. Consult the documentation for the target attribute for more
|
|
information.
|
|
|
|
- ...
|
|
|
|
Windows Support
|
|
---------------
|
|
|
|
Clang's support for building native Windows programs ...
|
|
|
|
|
|
C Language Changes in Clang
|
|
---------------------------
|
|
|
|
- ...
|
|
|
|
...
|
|
|
|
C11 Feature Support
|
|
^^^^^^^^^^^^^^^^^^^
|
|
|
|
...
|
|
|
|
C++ Language Changes in Clang
|
|
-----------------------------
|
|
|
|
- ...
|
|
|
|
C++1z Feature Support
|
|
^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
...
|
|
|
|
Objective-C Language Changes in Clang
|
|
-------------------------------------
|
|
|
|
...
|
|
|
|
OpenCL C Language Changes in Clang
|
|
----------------------------------
|
|
|
|
...
|
|
|
|
OpenMP Support in Clang
|
|
----------------------------------
|
|
|
|
- ...
|
|
|
|
CUDA Support in Clang
|
|
---------------------
|
|
|
|
- Clang will now try to locate the CUDA installation next to :program:`ptxas`
|
|
in the `PATH` environment variable. This behavior can be turned off by passing
|
|
the new flag `--cuda-path-ignore-env`.
|
|
|
|
- Clang now supports generating object files with relocatable device code. This
|
|
feature needs to be enabled with `-fcuda-rdc` and my result in performance
|
|
penalties compared to whole program compilation. Please note that NVIDIA's
|
|
:program:`nvcc` must be used for linking.
|
|
|
|
Internal API Changes
|
|
--------------------
|
|
|
|
These are major API changes that have happened since the 6.0.0 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.
|
|
|
|
- ...
|
|
|
|
AST Matchers
|
|
------------
|
|
|
|
- ...
|
|
|
|
clang-format
|
|
------------
|
|
|
|
- ...
|
|
|
|
libclang
|
|
--------
|
|
|
|
...
|
|
|
|
|
|
Static Analyzer
|
|
---------------
|
|
|
|
- ...
|
|
|
|
...
|
|
|
|
Undefined Behavior Sanitizer (UBSan)
|
|
------------------------------------
|
|
|
|
* ...
|
|
|
|
Core Analysis Improvements
|
|
==========================
|
|
|
|
- ...
|
|
|
|
New Issues Found
|
|
================
|
|
|
|
- ...
|
|
|
|
Python Binding Changes
|
|
----------------------
|
|
|
|
The following methods have been added:
|
|
|
|
- ...
|
|
|
|
Significant Known Problems
|
|
==========================
|
|
|
|
Additional Information
|
|
======================
|
|
|
|
A wide variety of additional information is available on the `Clang web
|
|
page <http://clang.llvm.org/>`_. 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 <http://lists.llvm.org/mailman/listinfo/cfe-dev>`_.
|