xref: /linux/scripts/generate_rust_analyzer.py (revision cd3a56ac2d132beea747f7b41cc085c82fe2eac0)
1#!/usr/bin/env python3
2# SPDX-License-Identifier: GPL-2.0
3"""generate_rust_analyzer - Generates the `rust-project.json` file for `rust-analyzer`.
4"""
5
6import argparse
7import json
8import logging
9import os
10import pathlib
11import subprocess
12import sys
13
14def args_crates_cfgs(cfgs):
15    crates_cfgs = {}
16    for cfg in cfgs:
17        crate, vals = cfg.split("=", 1)
18        crates_cfgs[crate] = vals.replace("--cfg", "").split()
19
20    return crates_cfgs
21
22def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
23    # Generate the configuration list.
24    cfg = []
25    with open(objtree / "include" / "generated" / "rustc_cfg") as fd:
26        for line in fd:
27            line = line.replace("--cfg=", "")
28            line = line.replace("\n", "")
29            cfg.append(line)
30
31    # Now fill the crates list -- dependencies need to come first.
32    #
33    # Avoid O(n^2) iterations by keeping a map of indexes.
34    crates = []
35    crates_indexes = {}
36    crates_cfgs = args_crates_cfgs(cfgs)
37
38    def append_crate(display_name, root_module, deps, cfg=[], is_workspace_member=True, is_proc_macro=False):
39        crate = {
40            "display_name": display_name,
41            "root_module": str(root_module),
42            "is_workspace_member": is_workspace_member,
43            "is_proc_macro": is_proc_macro,
44            "deps": [{"crate": crates_indexes[dep], "name": dep} for dep in deps],
45            "cfg": cfg,
46            "edition": "2021",
47            "env": {
48                "RUST_MODFILE": "This is only for rust-analyzer"
49            }
50        }
51        if is_proc_macro:
52            proc_macro_dylib_name = subprocess.check_output(
53                [os.environ["RUSTC"], "--print", "file-names", "--crate-name", display_name, "--crate-type", "proc-macro", "-"],
54                stdin=subprocess.DEVNULL,
55            ).decode('utf-8').strip()
56            crate["proc_macro_dylib_path"] = f"{objtree}/rust/{proc_macro_dylib_name}"
57        crates_indexes[display_name] = len(crates)
58        crates.append(crate)
59
60    def append_sysroot_crate(
61        display_name,
62        deps,
63        cfg=[],
64    ):
65        append_crate(
66            display_name,
67            sysroot_src / display_name / "src" / "lib.rs",
68            deps,
69            cfg,
70            is_workspace_member=False,
71        )
72
73    # NB: sysroot crates reexport items from one another so setting up our transitive dependencies
74    # here is important for ensuring that rust-analyzer can resolve symbols. The sources of truth
75    # for this dependency graph are `(sysroot_src / crate / "Cargo.toml" for crate in crates)`.
76    append_sysroot_crate("core", [], cfg=crates_cfgs.get("core", []))
77    append_sysroot_crate("alloc", ["core"])
78    append_sysroot_crate("std", ["alloc", "core"])
79    append_sysroot_crate("proc_macro", ["core", "std"])
80
81    append_crate(
82        "compiler_builtins",
83        srctree / "rust" / "compiler_builtins.rs",
84        [],
85    )
86
87    append_crate(
88        "macros",
89        srctree / "rust" / "macros" / "lib.rs",
90        ["std", "proc_macro"],
91        is_proc_macro=True,
92    )
93
94    append_crate(
95        "build_error",
96        srctree / "rust" / "build_error.rs",
97        ["core", "compiler_builtins"],
98    )
99
100    def append_crate_with_generated(
101        display_name,
102        deps,
103    ):
104        append_crate(
105            display_name,
106            srctree / "rust"/ display_name / "lib.rs",
107            deps,
108            cfg=cfg,
109        )
110        crates[-1]["env"]["OBJTREE"] = str(objtree.resolve(True))
111        crates[-1]["source"] = {
112            "include_dirs": [
113                str(srctree / "rust" / display_name),
114                str(objtree / "rust")
115            ],
116            "exclude_dirs": [],
117        }
118
119    append_crate_with_generated("bindings", ["core"])
120    append_crate_with_generated("uapi", ["core"])
121    append_crate_with_generated("kernel", ["core", "macros", "build_error", "bindings", "uapi"])
122
123    def is_root_crate(build_file, target):
124        try:
125            return f"{target}.o" in open(build_file).read()
126        except FileNotFoundError:
127            return False
128
129    # Then, the rest outside of `rust/`.
130    #
131    # We explicitly mention the top-level folders we want to cover.
132    extra_dirs = map(lambda dir: srctree / dir, ("samples", "drivers"))
133    if external_src is not None:
134        extra_dirs = [external_src]
135    for folder in extra_dirs:
136        for path in folder.rglob("*.rs"):
137            logging.info("Checking %s", path)
138            name = path.name.replace(".rs", "")
139
140            # Skip those that are not crate roots.
141            if not is_root_crate(path.parent / "Makefile", name) and \
142               not is_root_crate(path.parent / "Kbuild", name):
143                continue
144
145            logging.info("Adding %s", name)
146            append_crate(
147                name,
148                path,
149                ["core", "kernel"],
150                cfg=cfg,
151            )
152
153    return crates
154
155def main():
156    parser = argparse.ArgumentParser()
157    parser.add_argument('--verbose', '-v', action='store_true')
158    parser.add_argument('--cfgs', action='append', default=[])
159    parser.add_argument("srctree", type=pathlib.Path)
160    parser.add_argument("objtree", type=pathlib.Path)
161    parser.add_argument("sysroot", type=pathlib.Path)
162    parser.add_argument("sysroot_src", type=pathlib.Path)
163    parser.add_argument("exttree", type=pathlib.Path, nargs="?")
164    args = parser.parse_args()
165
166    logging.basicConfig(
167        format="[%(asctime)s] [%(levelname)s] %(message)s",
168        level=logging.INFO if args.verbose else logging.WARNING
169    )
170
171    # Making sure that the `sysroot` and `sysroot_src` belong to the same toolchain.
172    assert args.sysroot in args.sysroot_src.parents
173
174    rust_project = {
175        "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree, args.cfgs),
176        "sysroot": str(args.sysroot),
177    }
178
179    json.dump(rust_project, sys.stdout, sort_keys=True, indent=4)
180
181if __name__ == "__main__":
182    main()
183