C++: introduce automatic installation of dependencies in the autobuilder

CHANGELOG.md

@@ -4,7 +4,7 @@ See the [releases page](https://github.com/github/codeql-action/releases) for th
 
 ## [UNRELEASED]
 
-No user facing changes.
+- We are rolling out a feature in October 2023 that will improve the success rate of C/C++ autobuild. [#1889](https://github.com/github/codeql-action/pull/1889)
 
 ## 2.21.8 - 19 Sep 2023
 

queries/default-setup-environment-variables.ql

@@ -23,7 +23,7 @@ predicate isSafeForDefaultSetup(string envVar) {
       "GITHUB_BASE_REF", "GITHUB_EVENT_NAME", "GITHUB_JOB", "GITHUB_RUN_ATTEMPT", "GITHUB_RUN_ID",
       "GITHUB_SHA", "GITHUB_REPOSITORY", "GITHUB_SERVER_URL", "GITHUB_TOKEN", "GITHUB_WORKFLOW",
       "GITHUB_WORKSPACE", "GOFLAGS", "ImageVersion", "JAVA_TOOL_OPTIONS", "RUNNER_ARCH",
-      "RUNNER_NAME", "RUNNER_OS", "RUNNER_TEMP", "RUNNER_TOOL_CACHE"
+      "RUNNER_ENVIRONMENT", "RUNNER_NAME", "RUNNER_OS", "RUNNER_TEMP", "RUNNER_TOOL_CACHE"
     ]
 }
 

src/autobuild.ts

@@ -1,7 +1,14 @@
-import { getCodeQL } from "./codeql";
+import * as core from "@actions/core";
+
+import { getTemporaryDirectory, getWorkflowEventName } from "./actions-util";
+import { getGitHubVersion } from "./api-client";
+import { CodeQL, getCodeQL } from "./codeql";
 import * as configUtils from "./config-utils";
-import { Language, isTracedLanguage } from "./languages";
+import { Feature, featureConfig, Features } from "./feature-flags";
+import { isTracedLanguage, Language } from "./languages";
 import { Logger } from "./logging";
+import { parseRepositoryNwo } from "./repository";
+import { getRequiredEnvParam } from "./util";
 
 export async function determineAutobuildLanguages(
   config: configUtils.Config,
@@ -91,13 +98,57 @@ export async function determineAutobuildLanguages(
   return languages;
 }
 
+async function setupCppAutobuild(codeql: CodeQL, logger: Logger) {
+  const envVar = featureConfig[Feature.CppDependencyInstallation].envVar;
+  const featureName = "C++ automatic installation of dependencies";
+  const envDoc =
+    "https://docs.github.com/en/actions/learn-github-actions/variables#defining-environment-variables-for-a-single-workflow";
+  const gitHubVersion = await getGitHubVersion();
+  const repositoryNwo = parseRepositoryNwo(
+    getRequiredEnvParam("GITHUB_REPOSITORY"),
+  );
+  const features = new Features(
+    gitHubVersion,
+    repositoryNwo,
+    getTemporaryDirectory(),
+    logger,
+  );
+  if (await features.getValue(Feature.CppDependencyInstallation, codeql)) {
+    // disable autoinstall on self-hosted runners unless explicitly requested
+    if (
+      process.env["RUNNER_ENVIRONMENT"] === "self-hosted" &&
+      process.env[envVar] !== "true"
+    ) {
+      logger.info(
+        `Disabling ${featureName} as we are on a self-hosted runner.${
+          getWorkflowEventName() !== "dynamic"
+            ? ` To override this, set the ${envVar} environment variable to 'true' in your workflow (see ${envDoc}).`
+            : ""
+        }`,
+      );
+      core.exportVariable(envVar, "false");
+    } else {
+      logger.info(
+        `Enabling ${featureName}. This can be disabled by setting the ${envVar} environment variable to 'false' (see ${envDoc}).`,
+      );
+      core.exportVariable(envVar, "true");
+    }
+  } else {
+    logger.info(`Disabling ${featureName}.`);
+    core.exportVariable(envVar, "false");
+  }
+}
+
 export async function runAutobuild(
   language: Language,
   config: configUtils.Config,
   logger: Logger,
 ) {
   logger.startGroup(`Attempting to automatically build ${language} code`);
   const codeQL = await getCodeQL(config.codeQLCmd);
+  if (language === Language.cpp) {
+    await setupCppAutobuild(codeQL, logger);
+  }
   await codeQL.runAutobuild(language);
   logger.endGroup();
 }

src/feature-flags.ts

@@ -51,6 +51,7 @@ export enum Feature {
   AnalysisSummaryV2Enabled = "analysis_summary_v2_enabled",
   CliConfigFileEnabled = "cli_config_file_enabled",
   CodeqlJavaLombokEnabled = "codeql_java_lombok_enabled",
+  CppDependencyInstallation = "cpp_dependency_installation_enabled",
   DisableKotlinAnalysisEnabled = "disable_kotlin_analysis_enabled",
   DisablePythonDependencyInstallationEnabled = "disable_python_dependency_installation_enabled",
   EvaluatorIntraLayerParallelismEnabled = "evaluator_intra_layer_parallelism_enabled",
@@ -74,6 +75,11 @@ export const featureConfig: Record<
     minimumVersion: "2.14.0",
     defaultValue: false,
   },
+  [Feature.CppDependencyInstallation]: {
+    envVar: "CODEQL_EXTRACTOR_CPP_AUTOINSTALL_DEPENDENCIES",
+    minimumVersion: "2.15.0",
+    defaultValue: false,
+  },
   [Feature.DisableKotlinAnalysisEnabled]: {
     envVar: "CODEQL_DISABLE_KOTLIN_ANALYSIS",
     minimumVersion: undefined,