Include rust-analyzer-proc-macro-srv

Rust-analyzer needs this binary to expand proc macros. This is
especially important with the chromium::import! macro, since without
expanding the macro rust-analyzer cannot know about any dependencies.

The only way to include this binary is to set `extended = true` and
pass it in the `tools` list in config.toml, so do that.

Bug: None
Change-Id: I51f639b7a173a0f3a44b2dc3b57d5190a2eb9d80

Cq-Include-Trybots: luci.chromium.try:android-rust-arm32-rel,android-rust-arm64-dbg,android-rust-arm64-rel,linux-rust-x64-dbg,linux-rust-x64-rel,mac-rust-x64-dbg,win-rust-x64-dbg,win-rust-x64-rel
Change-Id: I51f639b7a173a0f3a44b2dc3b57d5190a2eb9d80
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5640314
Auto-Submit: Collin Baker <collinbaker@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1319723}
NOKEYCHECK=True
GitOrigin-RevId: 40573212d3c8beb5bf8bcc506340eab369a10356

Author: chbaker0

build_rust.py

@@ -163,12 +163,6 @@
     'src/tools/rustfmt'
 ]
 
-# Desired tools and libraries in our Rust toolchain.
-DISTRIBUTION_ARTIFACTS = [
-    'cargo', 'clippy', 'compiler/rustc', 'library/std', 'rust-analyzer',
-    'rustfmt', 'src'
-]
-
 # Which test suites to run. Any failure will fail the build.
 TEST_SUITES = [
     'library/std',
@@ -827,8 +821,7 @@ def main():
     if os.path.exists(RUST_TOOLCHAIN_OUT_DIR):
         RmTree(RUST_TOOLCHAIN_OUT_DIR)
 
-    artifacts = DISTRIBUTION_ARTIFACTS
-    xpy.run('install', xpy_args + artifacts)
+    xpy.run('install', [])
 
     # Copy additional vendored crates required for building stdlib.
     print(f'Copying vendored dependencies to {RUST_TOOLCHAIN_OUT_DIR} ...')

config.toml.template

@@ -34,6 +34,19 @@ docs = false
 # with the rust compiler we build.
 profiler = true
 
+# With `extended = true`, `x.py install` will install rustc and the listed
+# tools. This is the *only* way to install rust-analyzer-proc-macro-srv, which
+# is necessary to use rust-analyzer.
+extended = true
+tools = [
+    "cargo",
+    "clippy",
+    "rustfmt",
+    "rust-analyzer",
+    "rust-analyzer-proc-macro-srv",
+    "src",
+]
+
 [install]
 prefix = "$INSTALL_DIR"
 sysconfdir = "etc"

update_rust.py

@@ -36,7 +36,7 @@
 # this back to its previous value _AND_ set `OVERRIDE_CLANG_REVISION` below
 # to the `CLANG_REVISION` that was in place before the roll.
 RUST_REVISION = '3cf924b934322fd7b514600a7dc84fc517515346'
-RUST_SUB_REVISION = 1
+RUST_SUB_REVISION = 2
 
 # If not None, this overrides the `CLANG_REVISION` in
 # //tools/clang/scripts/update.py in order to download a Rust toolchain that