add rust-analyzer make target

This target creates ${objtree}/rust-project.json which can be read by
rust-analyzer to help with autocompletion for the kernel crate.

The raw bindings do not work yet, as rust-analyzer seems to have a
problem with the include macro.

Signed-off-by: Finn Behrens <[email protected]>

Author: kloenk

Documentation/rust/quick-start.rst

@@ -155,11 +155,8 @@ definition, and other features.
 ``rust-analyzer`` will need to be
 `configured <https://rust-analyzer.github.io/manual.html#non-cargo-based-projects>`_
 to work with the kernel by adding a ``rust-project.json`` file in the root folder.
-The example ``Documentation/rust/rust-project.json`` can
-be used after updating ``sysroot_src`` and including the relevant modules.
-The path to ``sysroot_src`` is given by::
-
-    $(rustc --print sysroot)/lib/rustlib/src/rust/library
+A ``rust-project.json`` can be generated by building the Make target ``rust-analyzer``,
+which will create a ``rust-project.json`` in the root of the output directory.
 
 
 Configuration

Documentation/rust/rust-project.json

@@ -1738,6 +1738,8 @@ help:
 	@echo  '		    is formatted, printing a diff otherwise.'
 	@echo  '  rustdoc	  - Generate Rust documentation'
 	@echo  '		    (requires kernel .config)'
+	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
+	@echo  '		    (requires kernel .config)'
 	@echo  ''
 	@$(if $(dtstree), \
 		echo 'Devicetree:'; \
@@ -1830,6 +1832,10 @@ rustfmt:
 rustfmtcheck:
 	find -name '*.rs' | xargs $(RUSTFMT) --check
 
+# IDE support targets
+PHONY += rust-analyzer
+rust-analyzer: prepare0
+	$(Q)$(MAKE) $(build)=rust $@
 
 # Misc
 # ---------------------------------------------------------------------------

Makefile

@@ -150,3 +150,6 @@ $(objtree)/rust/kernel.o: private rustc_target_flags = --extern alloc \
 $(objtree)/rust/kernel.o: $(srctree)/rust/kernel/lib.rs $(objtree)/rust/alloc.o \
     $(objtree)/rust/libmodule.so $(objtree)/rust/bindings_generated.rs FORCE
 	$(call if_changed_dep,rustc_library)
+
+rust-analyzer:
+	$(Q)$(srctree)/scripts/generate_rust_analyzer.py $(srctree) $(objtree) $(RUST_LIB_SRC) $(abspath $(objtree)/rust/bindings_generated.rs) > $(objtree)/rust-project.json

rust/Makefile

@@ -0,0 +1,193 @@
+#!/usr/bin/env python3
+import sys
+import os
+from os import path
+from dataclasses import dataclass
+import json
+
+
+srctree = sys.argv[1]
+objtree = sys.argv[2]
+lib_src = sys.argv[3]
+bindgen_file = sys.argv[4]
+
+crate_list = []
+
+class RustProjectCreator:
+    crate_list = []
+    cfgs = []
+    srctree = ""
+    objtree = ""
+    lib_src = ""
+    bindgen_file = ""
+
+    def __init__(self, srctree = sys.argv[1], objtree = sys.argv[2], lib_src = sys.argv[3], bindgen_file = sys.argv[4]):
+        self.srctree = srctree
+        self.objtree = objtree
+        self.lib_src = lib_src
+        self.bindgen_file = bindgen_file
+        self.cfgs = self.generate_cfgs()
+
+    def find(self, list, name):
+        pos = -1
+        for x in list:
+            pos += 1
+            if x['display_name'] == name:
+                return pos
+        raise RuntimeError(f'crate \'{name}\' could not be found')
+
+    def generate_deps(self, deps):
+        return [{"crate": self.find(self.crate_list, x), "name": x} for x in deps]
+
+    def generate_cfgs(self):
+        ret = []
+        with open( objtree + "/include/generated/rustc_cfg") as f:
+            for line in f:
+                line = line.replace('--cfg=', '')
+                line = line.replace('\n', '')
+                ret.append(line)
+        return ret
+
+    def get_default_deps(self):
+        return self.generate_deps(["core", "alloc", "kernel"])
+
+    def generate_crate(self, name, module, member = True, deps = None, cfg = None, edition = "2018"):
+        if deps == None:
+            deps = self.get_default_deps()
+        if cfg == None:
+            cfg = self.cfgs
+
+        return {
+            "display_name": name,
+            "root_module": module,
+            "edition": edition,
+            "is_workspace_member": member,
+            "cfg": cfg,
+            "deps": deps,
+            "env": {
+                "RUST_MODFILE": "This is only for rust-analyzer"
+            }
+        }
+
+    def generate_kernel(self):
+        # core
+        self.crate_list.append(
+            self.generate_crate(
+                name="core",
+                module=self.lib_src + "/core/src/lib.rs",
+                member=False,
+                deps=[],
+                cfg=[]
+            )
+        )
+
+        # compiler_builtins
+        self.crate_list.append(
+            self.generate_crate(
+                name="compiler_builtins",
+                module=self.srctree + "/rust/compiler_builtins.rs",
+                deps=[],
+                cfg=[]
+            )
+        )
+
+        # alloc
+        self.crate_list.append(
+            self.generate_crate(
+                name="alloc",
+                module=lib_src + "/alloc/src/lib.rs",
+                member=False,
+                deps=self.generate_deps(["core", "compiler_builtins"]),
+                cfg=[]
+            )
+        )
+
+        # module
+        module = self.generate_crate(
+            name="module",
+            module=self.srctree + "/rust/module.rs",
+            deps=[],
+            cfg=[],
+        )
+        module["proc_macro_dylib_path"] = "rust/libmodule.so"
+        self.crate_list.append(
+            module
+        )
+
+        # kernel
+        kernel = self.generate_crate(
+            name="kernel",
+            module=self.srctree + "/rust/kernel/lib.rs",
+            deps=self.generate_deps(["core", "alloc", "module"]),
+        )
+        kernel["env"]["RUST_BINDINGS_FILE"] = self.bindgen_file
+        kernel["source"] = {
+            "include_dirs": [ self.srctree + "/rust/kernel", self.objtree + "/rust" ],
+            "exclude_dirs": []
+        }
+        self.crate_list.append(kernel)
+
+    def does_file_contains(self, filepath, search):
+        with open (filepath) as f:
+            for line in f:
+                if search in line:
+                    return True
+        return False
+
+    def check_and_generate(self, filepath):
+        file = path.basename(filepath)
+        makefile = path.dirname(filepath) + "/Makefile"
+        name = file.replace('.rs', '')
+        objname = name + ".o"
+        print("checking " + objname, file=sys.stderr)
+        if self.does_file_contains(makefile, objname):
+            print("building crate " + name, file=sys.stderr)
+            return self.generate_crate(
+                name=name,
+                module=filepath,
+                #deps=self.get_default_deps()
+            )
+
+
+    def find_rs(self, tree):
+        ret = []
+        for root, dirs, files in os.walk(tree):
+            for file in files:
+                if file.endswith(".rs"):
+                    ret.append(path.join(root, file))
+        return ret
+
+    def generate_samples(self):
+        ret = []
+        for x in self.find_rs(self.srctree + "/samples/rust"):
+            sample = self.check_and_generate(x)
+            if sample:
+                ret.append(sample)
+        self.crate_list = self.crate_list + ret
+
+    def generate_drivers(self):
+        ret = []
+        for x in self.find_rs(self.srctree + "/drivers"):
+            driver = self.check_and_generate(x)
+            if driver:
+                ret.append(driver)
+        self.crate_list = self.crate_list + ret
+
+def main():
+    if (len(sys.argv) != 5):
+        print("Not enough arguments")
+        sys.exit(-1)
+    project = RustProjectCreator()
+    project.generate_kernel()
+    project.generate_samples()
+    project.generate_drivers()
+
+    rust_project = {
+        "crates": project.crate_list,
+        "sysroot_src": project.lib_src
+    }
+
+    json.dump(rust_project, sys.stdout, sort_keys=True, indent=4)
+
+if __name__ == "__main__":
+    main()