[PATCH 01/18] scripts: generate_rust_analyzer: support passing env vars

[Miguel Ojeda <ojeda@kernel.org>]

A future commit adding `zerocopy` support will need to pass an environment
variable during its build.

Thus add support for an `--envs` parameter, similar to `--cfgs`, that
allows to pass a map of variables to set for a given crate.

This allows us to keep a single source of truth for those values.

No change intended in the generated `rust-project.json`.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 scripts/generate_rust_analyzer.py | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index d5f9a0ca742c..cede76af8425 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -26,6 +26,14 @@ def args_crates_cfgs(cfgs: List[str]) -> Dict[str, List[str]]:
 
     return crates_cfgs
 
+def args_crates_envs(envs: List[str]) -> Dict[str, Dict[str, str]]:
+    crates_envs = {}
+    for env in envs:
+        crate, vals = env.split("=", 1)
+        crates_envs[crate] = dict(v.split("=", 1) for v in vals.split())
+
+    return crates_envs
+
 class Dependency(TypedDict):
     crate: int
     name: str
@@ -61,6 +69,7 @@ def generate_crates(
     sysroot_src: pathlib.Path,
     external_src: Optional[pathlib.Path],
     cfgs: List[str],
+    envs: List[str],
     core_edition: str,
 ) -> List[Crate]:
     # Generate the configuration list.
@@ -74,6 +83,7 @@ def generate_crates(
     # Now fill the crates list.
     crates: List[Crate] = []
     crates_cfgs = args_crates_cfgs(cfgs)
+    crates_envs = args_crates_envs(envs)
 
     def get_crate_name(path: pathlib.Path) -> str:
         return invoke_rustc(["--print", "crate-name", str(path)])
@@ -92,6 +102,10 @@ def generate_crates(
             is_workspace_member if is_workspace_member is not None else True
         )
         edition = edition if edition is not None else "2021"
+        crate_env = {
+            "RUST_MODFILE": "This is only for rust-analyzer"
+        }
+        crate_env.update(crates_envs.get(display_name, {}))
         return {
             "display_name": display_name,
             "root_module": str(root_module),
@@ -99,9 +113,7 @@ def generate_crates(
             "deps": deps,
             "cfg": cfg,
             "edition": edition,
-            "env": {
-                "RUST_MODFILE": "This is only for rust-analyzer"
-            }
+            "env": crate_env,
         }
 
     def append_proc_macro_crate(
@@ -347,6 +359,7 @@ def main() -> None:
     parser = argparse.ArgumentParser()
     parser.add_argument('--verbose', '-v', action='store_true')
     parser.add_argument('--cfgs', action='append', default=[])
+    parser.add_argument('--envs', action='append', default=[])
     parser.add_argument("core_edition")
     parser.add_argument("srctree", type=pathlib.Path)
     parser.add_argument("objtree", type=pathlib.Path)
@@ -357,6 +370,7 @@ def main() -> None:
     class Args(argparse.Namespace):
         verbose: bool
         cfgs: List[str]
+        envs: List[str]
         srctree: pathlib.Path
         objtree: pathlib.Path
         sysroot: pathlib.Path
@@ -372,7 +386,7 @@ def main() -> None:
     )
 
     rust_project = {
-        "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree, args.cfgs, args.core_edition),
+        "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree, args.cfgs, args.envs, args.core_edition),
         "sysroot": str(args.sysroot),
     }
 
-- 
2.54.0