Support rust analysis

pr-checks/checks/rust.yml

@@ -0,0 +1,23 @@
+name: "Rust analysis"
+description: "Tests creation of a Rust database"
+versions: ["linked", "default", "nightly-latest"]
+operatingSystems: ["ubuntu"]
+steps:
+  - uses: ./../action/init
+    with:
+      languages: rust
+      tools: ${{ steps.prepare-test.outputs.tools-url }}
+    env:
+      CODEQL_ACTION_RUST_ANALYSIS: true
+  - uses: ./../action/analyze
+    id: analysis
+    with:
+      upload-database: false
+  - name: Check database
+    shell: bash
+    run: |
+      RUST_DB="${{ fromJson(steps.analysis.outputs.db-locations).rust }}"
+      if [[ ! -d "$RUST_DB" ]]; then
+        echo "Did not create a database for Rust."
+        exit 1
+      fi

src/feature-flags.ts

@@ -53,6 +53,7 @@ export enum Feature {
   ExtractToToolcache = "extract_to_toolcache",
   PythonDefaultIsToNotExtractStdlib = "python_default_is_to_not_extract_stdlib",
   QaTelemetryEnabled = "qa_telemetry_enabled",
+  RustAnalysis = "rust_analysis",
   ZstdBundleStreamingExtraction = "zstd_bundle_streaming_extraction",
 }
 
@@ -148,6 +149,11 @@ export const featureConfig: Record<
     minimumVersion: undefined,
     toolsFeature: ToolsFeature.PythonDefaultIsToNotExtractStdlib,
   },
+  [Feature.RustAnalysis]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_RUST_ANALYSIS",
+    minimumVersion: "2.19.3",
+  },
   [Feature.QaTelemetryEnabled]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_QA_TELEMETRY",

src/init-action.ts

@@ -3,6 +3,7 @@ import * as path from "path";
 
 import * as core from "@actions/core";
 import * as io from "@actions/io";
+import * as semver from "semver";
 import { v4 as uuidV4 } from "uuid";
 
 import {
@@ -13,6 +14,7 @@ import {
   getRequiredInput,
   getTemporaryDirectory,
   persistInputs,
+  isDefaultSetup,
 } from "./actions-util";
 import { getGitHubVersion } from "./api-client";
 import {
@@ -30,7 +32,7 @@ import {
   makeDiagnostic,
 } from "./diagnostics";
 import { EnvVar } from "./environment";
-import { Feature, Features } from "./feature-flags";
+import { Feature, featureConfig, Features } from "./feature-flags";
 import {
   checkInstallPython311,
   cleanupDatabaseClusterDirectory,
@@ -72,7 +74,6 @@ import {
   getErrorMessage,
 } from "./util";
 import { validateWorkflow } from "./workflow";
-
 /** Fields of the init status report that can be sent before `config` is populated. */
 interface InitStatusReport extends StatusReportBase {
   /** Value given by the user as the "tools" input. */
@@ -576,6 +577,31 @@ async function run() {
       core.exportVariable(bmnVar, value);
     }
 
+    // Set CODEQL_ENABLE_EXPERIMENTAL_FEATURES for rust
+    if (config.languages.includes(Language.rust)) {
+      const feat = Feature.RustAnalysis;
+      const minVer = featureConfig[feat].minimumVersion as string;
+      const envVar = "CODEQL_ENABLE_EXPERIMENTAL_FEATURES";
+      // if in default setup, it means the feature flag was on when rust was enabled
+      // if the feature flag gets turned off, let's not have rust analysis throwing a configuration error
+      // in that case rust analysis will be disabled only when default setup is refreshed
+      if (isDefaultSetup() || (await features.getValue(feat, codeql))) {
+        core.exportVariable(envVar, "true");
+      }
+      if (process.env[envVar] !== "true") {
+        throw new ConfigurationError(
+          `Experimental and not officially supported Rust analysis requires setting ${envVar}=true in the environment`,
+        );
+      }
+      const actualVer = (await codeql.getVersion()).version;
+      if (semver.lt(actualVer, minVer)) {
+        throw new ConfigurationError(
+          `Experimental rust analysis is supported by CodeQL CLI version ${minVer} or higher, but found version ${actualVer}`,
+        );
+      }
+      logger.info("Experimental rust analysis enabled");
+    }
+
     // Restore dependency cache(s), if they exist.
     if (shouldRestoreCache(config.dependencyCachingEnabled)) {
       await downloadDependencyCaches(config.languages, logger);

tests/multi-language-repo/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "test"
+version = "0.0.1"
+edition = "2021"
+[[bin]]
+name = "main"
+path = "main.rs"
+

tests/multi-language-repo/main.rs

@@ -0,0 +1,6 @@
+fn main() {
+  if true {
+    println!("Hello world!")
+  }
+}
+