rust-analyzer for out-of-tree modules

Author: vvarma

Makefile

@@ -1902,11 +1902,17 @@ help:
 	@echo  '  modules         - default target, build the module(s)'
 	@echo  '  modules_install - install the module'
 	@echo  '  clean           - remove generated files in module directory only'
+	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
 	@echo  ''
 
 # no-op for external module builds
 PHONY += modules_prepare
 
+# IDE support targets
+PHONY += rust-analyzer
+rust-analyzer:
+	$(Q)$(MAKE) $(build)=rust rust-analyzer-extmod
+
 endif # KBUILD_EXTMOD
 
 # ---------------------------------------------------------------------------

rust/Makefile

@@ -386,6 +386,10 @@ rust-analyzer:
 	$(Q)$(srctree)/scripts/generate_rust_analyzer.py $(srctree) $(objtree) \
 		$(RUST_LIB_SRC) > $(objtree)/rust-project.json
 
+rust-analyzer-extmod:
+	$(Q)$(srctree)/scripts/generate_rust_analyzer.py $(abs_srctree) $(abs_objtree) \
+		$(RUST_LIB_SRC) ${KBUILD_EXTMOD} > $(extmod_prefix)/rust-project.json
+
 $(obj)/core.o: private skip_clippy = 1
 $(obj)/core.o: private skip_flags = -Dunreachable_pub
 $(obj)/core.o: private rustc_target_flags = $(core-cfgs)

scripts/generate_rust_analyzer.py

@@ -8,8 +8,9 @@
 import logging
 import pathlib
 import sys
+import os
 
-def generate_crates(srctree, objtree, sysroot_src):
+def generate_crates(srctree, objtree, sysroot_src, external_src):
     # Generate the configuration list.
     cfg = []
     with open(objtree / "include" / "generated" / "rustc_cfg") as fd:
@@ -65,7 +66,7 @@ def append_crate(display_name, root_module, deps, cfg=[], is_workspace_member=Tr
         [],
         is_proc_macro=True,
     )
-    crates[-1]["proc_macro_dylib_path"] = "rust/libmacros.so"
+    crates[-1]["proc_macro_dylib_path"] = f"{objtree}/rust/libmacros.so"
 
     append_crate(
         "build_error",
@@ -98,13 +99,15 @@ def append_crate(display_name, root_module, deps, cfg=[], is_workspace_member=Tr
     # Then, the rest outside of `rust/`.
     #
     # We explicitly mention the top-level folders we want to cover.
-    for folder in ("samples", "drivers"):
+    extra_src_dirs = ["samples", "drivers"] if external_src is None else [external_src]
+
+    for folder in extra_src_dirs:
         for path in (srctree / folder).rglob("*.rs"):
             logging.info("Checking %s", path)
             name = path.name.replace(".rs", "")
 
             # Skip those that are not crate roots.
-            if f"{name}.o" not in open(path.parent / "Makefile").read():
+            if os.path.exists(path.parent / "Makefile") and f"{name}.o" not in open(path.parent / "Makefile").read():
                 continue
 
             logging.info("Adding %s", name)
@@ -123,6 +126,7 @@ def main():
     parser.add_argument("srctree", type=pathlib.Path)
     parser.add_argument("objtree", type=pathlib.Path)
     parser.add_argument("sysroot_src", type=pathlib.Path)
+    parser.add_argument("exttree", type=pathlib.Path, nargs='?')
     args = parser.parse_args()
 
     logging.basicConfig(
@@ -131,7 +135,7 @@ def main():
     )
 
     rust_project = {
-        "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src),
+        "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree),
         "sysroot_src": str(args.sysroot_src),
     }