Documentation: add minimum clang/llvm version

Based on a vote at the LLVM BoF at Plumbers 2020, we decided to start
small, supporting just one formal upstream release of LLVM for now.

We can probably widen the support window of supported versions over
time.  Also, note that LLVM's release process is different than GCC's.
GCC tends to have 1 major release per year while releasing minor updates
to the past 3 major versions.  LLVM tends to support one major release
and one minor release every six months.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200826191555.3350406-1-ndesaulniers@google.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/Documentation/kbuild/llvm.rst b/Documentation/kbuild/llvm.rst
index 2aac50b97921f09e9d777a4c39257f30f163efec..3f10a9c47551574b7987e804ecfc3ada0738e225 100644 (file)
--- a/Documentation/kbuild/llvm.rst
+++ b/Documentation/kbuild/llvm.rst
@@ -1,3 +1,5 @@
+.. _kbuild_llvm:
+
 ==============================
 Building Linux with Clang/LLVM
 ==============================
@@ -73,6 +75,8 @@ Getting Help
 - `Wiki <https://github.com/ClangBuiltLinux/linux/wiki>`_
 - `Beginner Bugs <https://github.com/ClangBuiltLinux/linux/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22>`_
 
+.. _getting_llvm:
+
 Getting LLVM
 -------------
 

diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
index ee741763a3fcf7d55e8a700d693851b4ac61470f..dac17711dc1123c5996c5468086168a8c55f126a 100644 (file)
--- a/Documentation/process/changes.rst
+++ b/Documentation/process/changes.rst
@@ -30,6 +30,7 @@ you probably needn't concern yourself with pcmciautils.
         Program        Minimal version       Command to check the version
 ====================== ===============  ========================================
 GNU C                  4.9              gcc --version
+Clang/LLVM (optional)  10.0.1           clang --version
 GNU make               3.81             make --version
 binutils               2.23             ld -v
 flex                   2.5.35           flex --version
@@ -68,6 +69,15 @@ GCC
 The gcc version requirements may vary depending on the type of CPU in your
 computer.
 
+Clang/LLVM (optional)
+---------------------
+
+The latest formal release of clang and LLVM utils (according to
+`releases.llvm.org <https://releases.llvm.org>`_) are supported for building
+kernels. Older releases aren't guaranteed to work, and we may drop workarounds
+from the kernel that were used to support older versions. Please see additional
+docs on :ref:`Building Linux with Clang/LLVM <kbuild_llvm>`.
+
 Make
 ----
 
@@ -331,6 +341,11 @@ gcc
 
 - <ftp://ftp.gnu.org/gnu/gcc/>
 
+Clang/LLVM
+----------
+
+- :ref:`Getting LLVM <getting_llvm>`.
+
 Make
 ----