Merge pull request #1444 from Nilstrieb/ra-rustc

Use `rust-analyzer.rustc.source` to get r-a working with rustc

Author: bjorn3

.vscode/settings.json

@@ -1,8 +1,9 @@
 {
     "editor.formatOnSave": true,
 
-    // source for rustc_* is not included in the rust-src component; disable the errors about this
+    // in case rustc.source is disabled for performance reasons; disable the errors about this
     "rust-analyzer.diagnostics.disabled": ["unresolved-extern-crate", "unresolved-macro-call"],
+    "rust-analyzer.rustc.source": "discover",
     "rust-analyzer.imports.granularity.enforce": true,
     "rust-analyzer.imports.granularity.group": "module",
     "rust-analyzer.imports.prefix": "crate",

Readme.md

@@ -121,6 +121,8 @@ You need to do this steps to successfully compile and use the cranelift backend
   * (Optional) run tests: `rustup run stage2 ./y.sh test`
 8. Now you can use your cg_clif build to compile other Rust programs, e.g. you can open any Rust crate and run commands like `$RustCheckoutDir/compiler/rustc_codegen_cranelift/dist/cargo-clif build --release`.
 
+You can also set `rust-analyzer.rustc.source` to your rust workspace to get rust-analyzer to understand your changes.
+
 ## Configuration
 
 See the documentation on the `BackendConfig` struct in [config.rs](src/config.rs) for all