mainlining shenanigans
3d32285fa9
Currently, you need to manually run scripts/gen_compile_commands.py
to create compile_commands.json. It parses all the .*.cmd files found
under the specified directory.
If you rebuild the kernel over again without 'make clean',
.*.cmd files from older builds will create stale entries in
compile_commands.json.
This commit wires up the compile_commands.json rule to Makefile, and
makes it parse only the .*.cmd files involved in the current build.
Pass $(KBUILD_VMLINUX_OBJS), $(KBUILD_VMLINUX_LIBS), and modules.order
to the script. The objects or archives linked to vmlinux are listed in
$(KBUILD_VMLINUX_OBJS) or $(KBUILD_VMLINUX_LIBS). All the modules are
listed in modules.order.
You can create compile_commands.json from Make:
$ make -j$(nproc) CC=clang compile_commands.json
You can also build vmlinux, modules, and compile_commands.json all
together in a single command:
$ make -j$(nproc) CC=clang all compile_commands.json
It works for M= builds as well. In this case, compile_commands.json
is created in the top directory of the external module.
This is convenient, but it has a drawback; the coverage of the
compile_commands.json is reduced because only the objects linked to
vmlinux or modules are handled. For example, the following C files are
not included in the compile_commands.json:
- Decompressor source files (arch/*/boot/)
- VDSO source files
- C files used to generate intermediates (e.g. kernel/bounds.c)
- Standalone host programs
I think it is fine for most developers because our main interest is
the kernel-space code.
If you want to cover all the compiled C files, please build the kernel,
then run the script manually as you did before:
$ make clean # if you want to remove stale .cmd files [optional]
$ make -j$(nproc) CC=clang
$ scripts/gen_compile_commands.py
Here is a note for out-of-tree builds. 'make compile_commands.json'
works with O= option, but please notice compile_commands.json is
created in the object tree instead of the source tree.
Some people may want to have compile_commands.json in the source tree
because Clang Tools searches for it through all parent paths of the
first input source file.
However, you cannot do this for O= builds. Kbuild should never generate
any build artifact in the source tree when O= is given because the
source tree might be read-only. Any write attempt to the source tree
is monitored and the violation may be reported. See the commit log of
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.