Add a convenience target generating the compilation database from a
built object tree, alongside the other developer conveniences (tags,
cscope, cloc -- the last of which already walks the same .cmd files):
make -C xen compile_commands.json
The output lands in the object tree root. For an in-tree build,
clangd and other consumers discover it there automatically when
opening files; for an out-of-tree build, symlink it into the source
tree root (consumers search the ancestors of the file being edited).
Note the database records the compiler invocations actually used.
With a clang build it is consumable by clangd as-is; for a gcc build,
clang-based tools may need a small .clangd configuration
(CompileFlags: Remove/Add) dropping gcc-only flags.
Also add the generated file to .gitignore.
Assisted-by: LLM
Signed-off-by: George Dunlap <gwd@xenproject.org>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Two changes from the Linux original:
- Linux's compiler invocations end with the source file
("... -c -o foo.o foo.c"), and the script's line pattern relies
on that; Xen's cmd_cc_o_c places "-c $<" before "-o" and "-MQ",
so on a Xen object tree the unmodified script matches nothing and
produces an empty database. Adjust _LINE_PATTERN to capture the
command up to and including "-c" plus the source file, dropping
the remainder, which database consumers do not need.
- Reword the docstring and help text to refer to Xen.
The support for reading object lists from archives and modules.order
is unused in Xen but retained to minimise divergence from the
original.
Assisted-by: LLM
Signed-off-by: George Dunlap <gwd@xenproject.org>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Xen's Kbuild-derived build system records the exact command line used
to compile each object in .<target>.o.cmd files. That is everything
needed to produce a compile_commands.json compilation database, the
format clangd and other tooling consume to provide accurate
cross-referencing (go to definition, find references, call hierarchy)
in LSP-capable editors.
Import scripts/clang-tools/gen_compile_commands.py from the Linux
kernel, unmodified, so that the provenance of the code is easy to
verify (commit 90efe2b9119f, Linux v6.16).
As-is the script produces an empty database on a Xen tree, since
Xen's compile command lines differ slightly from Linux's; the
following patch adapts it.
Assisted-by: LLM
Signed-off-by: George Dunlap <gwd@xenproject.org>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
George Dunlap