Ask rust_toolchain for rustc_srcs in rust_analyzer.bzl

WORKSPACE.bazel

@@ -2,7 +2,7 @@ workspace(name = "rules_rust")
 
 load("@rules_rust//rust:repositories.bzl", "rust_repositories")
 
-rust_repositories()
+rust_repositories(include_rustc_src = True)
 
 load("@rules_rust//proto:repositories.bzl", "rust_proto_repositories")
 

examples/WORKSPACE.bazel

@@ -11,3 +11,6 @@ deps()
 load(":examples_transitive_deps.bzl", "transitive_deps")
 
 transitive_deps()
+
+load("@rules_rust//rust:repositories.bzl", "rust_repositories")
+rust_repositories(include_rustc_src = True, version = "nightly", edition="2018")

rust/private/rust_analyzer.bzl

@@ -173,7 +173,16 @@ def create_crate(ctx, info, crate_mapping):
 # TODO(djmarcin): Run the cargo_build_scripts to gather env vars correctly.
 def _rust_analyzer_impl(ctx):
     rust_toolchain = find_toolchain(ctx)
-    sysroot_src = _exec_root_tmpl + rust_toolchain.rust_lib.label.workspace_root + "/lib/rustlib/src/library"
+
+    if not rust_toolchain.rustc_src:
+        fail(
+            "Current Rust toolchain doesn't contain rustc sources in `rustc_src` attribute.",
+            "These are needed by rust analyzer.",
+            "If you are using the default Rust toolchain, add `rust_repositories(include_rustc_src = True, ...).` to your WORKSPACE file.",
+        )
+    sysroot_src = rust_toolchain.rustc_src.label.package + "/library"
+    if rust_toolchain.rustc_src.label.workspace_root:
+        sysroot_src = _exec_root_tmpl + rust_toolchain.rustc_src.label.workspace_root + "/" + sysroot_src
 
     # Gather all crates and their dependencies into an array.
     # Dependencies are referenced by index, so leaves should come first.

rust/repositories.bzl

@@ -216,25 +216,6 @@ def BUILD_for_rustfmt(target_triple):
         binary_ext = system_to_binary_ext(system),
     )
 
-_build_file_for_rustc_src = """\
-load("@rules_rust//rust:toolchain.bzl", "rust_toolchain")
-
-filegroup(
-    name = "rustc_src",
-    srcs = glob(
-        [
-            "lib/rustlib/src/**/*.rs",
-        ],
-    ),
-    visibility = ["//visibility:public"],
-)
-"""
-
-def BUILD_for_rustc_src():
-    """Emits a BUILD file for the rustc src extracted files."""
-
-    return _build_file_for_rustc_src
-
 _build_file_for_clippy_template = """\
 load("@rules_rust//rust:toolchain.bzl", "rust_toolchain")
 
@@ -331,7 +312,7 @@ def BUILD_for_rust_toolchain(
 
     rustc_src = "None"
     if include_rustc_src:
-        rustc_src = "\"@{workspace_name}//:rustc_src\"".format(workspace_name = workspace_name)
+        rustc_src = "\"@{workspace_name}//lib/rustlib/src:rustc_src\"".format(workspace_name = workspace_name)
 
     return _build_file_for_rust_toolchain_template.format(
         toolchain_name = name,
@@ -495,8 +476,6 @@ def _load_rust_src(ctx):
 
     Args:
         ctx (ctx): A repository_ctx.
-    Returns:
-        string: The BUILD file contents for the rust source code
     """
     tool_suburl = produce_tool_suburl("rustc", "src", ctx.attr.version, ctx.attr.iso_date)
     static_rust = ctx.os.environ.get("STATIC_RUST_URL", "https://static.rust-lang.org")
@@ -514,7 +493,15 @@ def _load_rust_src(ctx):
         output = "lib/rustlib/src",
         stripPrefix = tool_path,
     )
-    return BUILD_for_rustc_src()
+    ctx.file(
+        "lib/rustlib/src/BUILD.bazel",
+        """\
+filegroup(
+    name = "rustc_src",
+    srcs = glob(["**/*"]),
+    visibility = ["//visibility:public"],
+)""",
+    )
 
 def _load_rust_stdlib(ctx, target_triple):
     """Loads a rust standard library and yields corresponding BUILD for it
@@ -599,10 +586,10 @@ def _rust_toolchain_repository_impl(ctx):
 
     _check_version_valid(ctx.attr.version, ctx.attr.iso_date)
 
-    build_components = [_load_rust_compiler(ctx)]
-
     if ctx.attr.include_rustc_src:
-        build_components.append(_load_rust_src(ctx))
+        _load_rust_src(ctx)
+
+    build_components = [_load_rust_compiler(ctx)]
 
     if ctx.attr.rustfmt_version:
         build_components.append(_load_rustfmt(ctx))