libvirt/docs/clangd.rst
Tim Small 3da8d8b5b1 docs: Add config instructions for clangd with libvirt
In build environments which use gcc as the default compiler, use of the
clangd LSP server (for enhanced code editing and navigation etc.) with
libvirt requires some additional configuration.  Detail this and link
from `hacking.rst`.

Signed-off-by: Tim Small <tim@seoss.co.uk>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2023-07-14 15:19:19 +02:00

52 lines
1.7 KiB
ReStructuredText

=========================
Using Clangd with Libvirt
=========================
`clangd <https://clangd.llvm.org/>`__ is an implementation of the
`language server protocol
<https://en.wikipedia.org/wiki/Language_Server_Protocol>`__ for C
and C++.
When paired with an LSP-compatible editor or IDE (e.g. emacs,
vim, vscode), ``clangd`` can helpful when working with libvirt's
C sources e.g. navigating the code base.
Whilst other C LSPs are available, ``clangd`` should work
correctly with the libvirt because clang is a supported compiler
for libvirt, and ``clangd`` is part of the same code base as
clang.
If clang is the default compiler on your system, then ``clangd``
can be used as soon as ``meson setup`` has been run.
If gcc is your build environment's default compiler, then
additional steps are required to use ``clangd``:
``clangd`` looks for a ``compile_commands.json`` file in the top
level directory of the project and also in the ``build/``
subdirectory to discover which include paths, compiler flags etc.
should be used when it parses each source file.
Meson creates a ``compile_commands.json`` in the build directory.
Meson defaults to the system's default C compiler. When the
default compiler is gcc, its ``compile_commands.json`` output
cannot be used with ``clangd`` due to differences in compiler
invocation flags when building libvirt.
Create a separate build directory with a ``clangd`` compatible
``compile_commands.json`` as follows:
::
CC=clang CXX=clang++ meson setup build-clang
Point ``clangd`` (v12 or later) at the correct
``compile_commands.json`` by placing the following into a
``.clangd`` file in the root of the project:
::
---
CompileFlags:
CompilationDatabase: "build-clang"