feat: persist DIL output to a .dil file for codeql_query_compile

After successful compilation with --dump-dil, extract the DIL content
from stdout and save it to a dedicated .dil file in a log directory.
The file path is appended to the tool response.

- Add logDir parameter to codeql_query_compile tool
- Create log directory and write .dil file post-execution
- Add server unit tests for DIL file persistence
- Update integration test assertions to verify DIL file output

Agent-Logs-Url: https://github.com/advanced-security/codeql-development-mcp-server/sessions/7ba868e5-1215-4130-bc06-10dfb15ebf14

Co-authored-by: data-douser <70299490+data-douser@users.noreply.github.com>

Author: Copilot

client/integration-tests/primitives/tools/codeql_query_compile/compile_query/test-config.json

@@ -2,5 +2,8 @@
   "toolName": "codeql_query_compile",
   "arguments": {
     "query": "server/ql/javascript/examples/src/ExampleQuery1/ExampleQuery1.ql"
+  },
+  "assertions": {
+    "responseContains": ["DIL file:", ".dil"]
   }
 }

server/dist/codeql-development-mcp-server.js

@@ -35004,7 +35004,7 @@ var require_view = __commonJS({
     var path3 = __require("node:path");
     var fs3 = __require("node:fs");
     var dirname9 = path3.dirname;
-    var basename10 = path3.basename;
+    var basename11 = path3.basename;
     var extname3 = path3.extname;
     var join22 = path3.join;
     var resolve15 = path3.resolve;
@@ -35043,7 +35043,7 @@ var require_view = __commonJS({
         var root = roots[i];
         var loc = resolve15(root, name);
         var dir = dirname9(loc);
-        var file = basename10(loc);
+        var file = basename11(loc);
         path4 = this.resolve(dir, file);
       }
       return path4;
@@ -35073,7 +35073,7 @@ var require_view = __commonJS({
       if (stat && stat.isFile()) {
         return path4;
       }
-      path4 = join22(dir, basename10(file, ext), "index" + ext);
+      path4 = join22(dir, basename11(file, ext), "index" + ext);
       stat = tryStat(path4);
       if (stat && stat.isFile()) {
         return path4;
@@ -38371,7 +38371,7 @@ var require_content_disposition = __commonJS({
     "use strict";
     module.exports = contentDisposition;
     module.exports.parse = parse4;
-    var basename10 = __require("path").basename;
+    var basename11 = __require("path").basename;
     var ENCODE_URL_ATTR_CHAR_REGEXP = /[\x00-\x20"'()*,/:;<=>?@[\\\]{}\x7f]/g;
     var HEX_ESCAPE_REGEXP = /%[0-9A-Fa-f]{2}/;
     var HEX_ESCAPE_REPLACE_REGEXP = /%([0-9A-Fa-f]{2})/g;
@@ -38406,9 +38406,9 @@ var require_content_disposition = __commonJS({
       if (typeof fallback === "string" && NON_LATIN1_REGEXP.test(fallback)) {
         throw new TypeError("fallback must be ISO-8859-1 string");
       }
-      var name = basename10(filename);
+      var name = basename11(filename);
       var isQuotedString = TEXT_REGEXP.test(name);
-      var fallbackName = typeof fallback !== "string" ? fallback && getlatin1(name) : basename10(fallback);
+      var fallbackName = typeof fallback !== "string" ? fallback && getlatin1(name) : basename11(fallback);
       var hasFallback = typeof fallbackName === "string" && fallbackName !== name;
       if (hasFallback || !isQuotedString || HEX_ESCAPE_REGEXP.test(name)) {
         params["filename*"] = name;
@@ -190955,7 +190955,7 @@ function cacheDatabaseAnalyzeResults(params, logger2) {
 // src/lib/cli-tool-registry.ts
 init_package_paths();
 import { existsSync as existsSync6, mkdirSync as mkdirSync8, realpathSync, rmSync, writeFileSync as writeFileSync4 } from "fs";
-import { delimiter as delimiter5, dirname as dirname5, isAbsolute as isAbsolute4, join as join10, resolve as resolve4 } from "path";
+import { delimiter as delimiter5, dirname as dirname5, basename as basename5, isAbsolute as isAbsolute4, join as join10, resolve as resolve4 } from "path";
 
 // ../node_modules/js-yaml/dist/js-yaml.mjs
 function isNothing(subject) {
@@ -193921,6 +193921,11 @@ function registerCLITool(server, definition) {
             mkdirSync8(outputDir, { recursive: true });
           }
         }
+        let compileLogDir;
+        if (name === "codeql_query_compile" && options["dump-dil"] !== false) {
+          compileLogDir = getOrCreateLogDirectory(customLogDir);
+          logger.info(`Using log directory for ${name}: ${compileLogDir}`);
+        }
         const rawAdditionalArgs = Array.isArray(options.additionalArgs) ? options.additionalArgs : [];
         delete options.additionalArgs;
         const managedFlagNames = /* @__PURE__ */ new Set([
@@ -194016,7 +194021,24 @@ function registerCLITool(server, definition) {
           const resolvedDb = typeof params.database === "string" ? resolveDatabasePath(params.database) : params.database;
           cacheDatabaseAnalyzeResults({ ...params, database: resolvedDb, output: options.output, format: options.format }, logger);
         }
-        const processedResult = resultProcessor(result, params);
+        let dilFilePath;
+        if (name === "codeql_query_compile" && result.success && compileLogDir && result.stdout) {
+          try {
+            const queryBaseName = query ? basename5(query, ".ql") : "query";
+            dilFilePath = join10(compileLogDir, `${queryBaseName}.dil`);
+            writeFileSync4(dilFilePath, result.stdout, "utf8");
+            logger.info(`Saved DIL output to ${dilFilePath}`);
+          } catch (dilError) {
+            logger.warn(`Failed to save DIL output: ${dilError}`);
+            dilFilePath = void 0;
+          }
+        }
+        let processedResult = resultProcessor(result, params);
+        if (dilFilePath) {
+          processedResult += `
+
+DIL file: ${dilFilePath}`;
+        }
         return {
           content: [{
             type: "text",
@@ -195288,7 +195310,7 @@ var codeqlPackLsTool = {
 
 // src/tools/codeql/profile-codeql-query-from-logs.ts
 import { existsSync as existsSync11, mkdirSync as mkdirSync9, writeFileSync as writeFileSync5 } from "fs";
-import { basename as basename6, dirname as dirname7, join as join15 } from "path";
+import { basename as basename7, dirname as dirname7, join as join15 } from "path";
 
 // src/lib/evaluator-log-parser.ts
 init_logger();
@@ -195620,7 +195642,7 @@ function buildDetailFile(profile, topN) {
   lines.push("");
   for (let qIdx = 0; qIdx < profile.queries.length; qIdx++) {
     const query = profile.queries[qIdx];
-    const qName = basename6(query.queryName);
+    const qName = basename7(query.queryName);
     lines.push(`== Query: ${qName} ==`);
     lines.push(`   Total: ${query.totalDurationMs.toFixed(2)}ms | Predicates evaluated: ${query.predicateCount} | Cache hits: ${query.cacheHits}`);
     lines.push("");
@@ -195779,7 +195801,7 @@ init_cli_executor();
 init_logger();
 import { writeFileSync as writeFileSync6, existsSync as existsSync12 } from "fs";
 import { createReadStream as createReadStream2 } from "fs";
-import { join as join16, dirname as dirname8, basename as basename7 } from "path";
+import { join as join16, dirname as dirname8, basename as basename8 } from "path";
 import { mkdirSync as mkdirSync10 } from "fs";
 import { createInterface as createInterface2 } from "readline";
 async function parseEvaluatorLog2(logPath) {
@@ -195905,7 +195927,7 @@ function formatAsMermaid(profile) {
   lines.push("```mermaid");
   lines.push("graph TD");
   lines.push("");
-  lines.push(`  QUERY["${basename7(profile.queryName)}<br/>Total: ${profile.totalDuration.toFixed(2)}ms"]`);
+  lines.push(`  QUERY["${basename8(profile.queryName)}<br/>Total: ${profile.totalDuration.toFixed(2)}ms"]`);
   lines.push("");
   profile.pipelines.forEach((pipeline) => {
     const nodeId = `P${pipeline.eventId}`;
@@ -196036,7 +196058,7 @@ function registerProfileCodeQLQueryTool(server) {
           ...outputFiles.map((f) => `  - ${f}`),
           "",
           "Profile Summary:",
-          `  - Query: ${basename7(profile.queryName)}`,
+          `  - Query: ${basename8(profile.queryName)}`,
           `  - Total Duration: ${profile.totalDuration.toFixed(2)} ms`,
           `  - Total Pipelines: ${profile.pipelines.length}`,
           `  - Total Events: ${profile.totalEvents}`,
@@ -196073,14 +196095,15 @@ function registerProfileCodeQLQueryTool(server) {
 // src/tools/codeql/query-compile.ts
 var codeqlQueryCompileTool = {
   name: "codeql_query_compile",
-  description: "Compile and validate CodeQL queries",
+  description: "Compile and validate CodeQL queries. By default, produces a .dil file containing the optimized DIL intermediate representation alongside the compilation output.",
   command: "codeql",
   subcommand: "query compile",
   inputSchema: {
     query: external_exports.string().describe("Path to the CodeQL query file (.ql)"),
     database: external_exports.string().optional().describe("Path to the CodeQL database"),
     "dump-dil": external_exports.boolean().optional().describe("Print the optimized DIL intermediate representation to standard output while compiling. Enabled by default; pass false or --no-dump-dil to disable."),
     library: external_exports.string().optional().describe("Path to query library"),
+    logDir: external_exports.string().optional().describe("Directory to write the .dil file. If not provided, a unique log directory is created automatically."),
     output: external_exports.string().optional().describe("Output file path"),
     warnings: external_exports.enum(["hide", "show", "error"]).optional().describe("How to handle compilation warnings"),
     verbose: external_exports.boolean().optional().describe("Enable verbose output"),
@@ -196737,7 +196760,7 @@ var codeqlResolveTestsTool = {
 
 // src/tools/codeql/search-ql-code.ts
 import { closeSync as closeSync2, createReadStream as createReadStream3, fstatSync as fstatSync2, lstatSync, openSync as openSync2, readdirSync as readdirSync8, readFileSync as readFileSync12, realpathSync as realpathSync2 } from "fs";
-import { basename as basename8, extname as extname2, join as join19, resolve as resolve9 } from "path";
+import { basename as basename9, extname as extname2, join as join19, resolve as resolve9 } from "path";
 import { createInterface as createInterface3 } from "readline";
 init_logger();
 var MAX_FILE_SIZE_BYTES = 5 * 1024 * 1024;
@@ -196763,7 +196786,7 @@ function collectFiles(paths, extensions, fileCount) {
       }
       fileCount.value++;
     } else if (stat.isDirectory()) {
-      if (SKIP_DIRS2.has(basename8(p))) return;
+      if (SKIP_DIRS2.has(basename9(p))) return;
       let realPath;
       try {
         realPath = realpathSync2(p);
@@ -198164,7 +198187,7 @@ function registerLanguageResources(server) {
 
 // src/prompts/workflow-prompts.ts
 import { access as access2 } from "fs/promises";
-import { basename as basename9, isAbsolute as isAbsolute7, normalize, relative as relative2, resolve as resolve13, sep as sep3 } from "path";
+import { basename as basename10, isAbsolute as isAbsolute7, normalize, relative as relative2, resolve as resolve13, sep as sep3 } from "path";
 import { fileURLToPath as fileURLToPath3 } from "url";
 
 // src/prompts/check-for-duplicated-code.prompt.md
@@ -198583,7 +198606,7 @@ ${content}`
         if (qpResult.blocked) return blockedPathError(qpResult, "query path");
         const resolvedQueryPath = qpResult.resolvedPath;
         if (qpResult.warning) warnings.push(qpResult.warning);
-        const derivedName = workshopName || basename9(resolvedQueryPath).replace(/\.(ql|qlref)$/, "").toLowerCase().replace(/[^a-z0-9]+/g, "-") || "codeql-workshop";
+        const derivedName = workshopName || basename10(resolvedQueryPath).replace(/\.(ql|qlref)$/, "").toLowerCase().replace(/[^a-z0-9]+/g, "-") || "codeql-workshop";
         const contextSection = buildWorkshopContext(
           resolvedQueryPath,
           language,

server/dist/codeql-development-mcp-server.js.map

@@ -13,7 +13,7 @@ import { resolveQueryPath } from './query-resolver';
 import { cacheDatabaseAnalyzeResults, processQueryRunResults } from './result-processor';
 import { getUserWorkspaceDir, packageRootDir } from '../utils/package-paths';
 import { existsSync, mkdirSync, realpathSync, rmSync, writeFileSync } from 'fs';
-import { delimiter, dirname, isAbsolute, join, resolve } from 'path';
+import { delimiter, dirname, basename, isAbsolute, join, resolve } from 'path';
 import * as yaml from 'js-yaml';
 import { createProjectTempDir } from '../utils/temp-dir';
 
@@ -556,6 +556,13 @@ export function registerCLITool(server: McpServer, definition: CLIToolDefinition
           }
         }
 
+        // Set up log directory for compile runs to persist DIL output
+        let compileLogDir: string | undefined;
+        if (name === 'codeql_query_compile' && options['dump-dil'] !== false) {
+          compileLogDir = getOrCreateLogDirectory(customLogDir as string | undefined);
+          logger.info(`Using log directory for ${name}: ${compileLogDir}`);
+        }
+
         // Extract additionalArgs from options so they are passed as raw CLI
         // arguments instead of being transformed into --additionalArgs=value
         // by buildCodeQLArgs.
@@ -717,8 +724,29 @@ export function registerCLITool(server: McpServer, definition: CLIToolDefinition
           cacheDatabaseAnalyzeResults({ ...params, database: resolvedDb, output: options.output, format: options.format }, logger);
         }
 
+        // Post-execution: persist DIL output to a .dil file for codeql_query_compile
+        let dilFilePath: string | undefined;
+        if (name === 'codeql_query_compile' && result.success && compileLogDir && result.stdout) {
+          try {
+            const queryBaseName = query
+              ? basename(query as string, '.ql')
+              : 'query';
+            dilFilePath = join(compileLogDir, `${queryBaseName}.dil`);
+            writeFileSync(dilFilePath, result.stdout, 'utf8');
+            logger.info(`Saved DIL output to ${dilFilePath}`);
+          } catch (dilError) {
+            logger.warn(`Failed to save DIL output: ${dilError}`);
+            dilFilePath = undefined;
+          }
+        }
+
         // Process the result
-        const processedResult = resultProcessor(result, params);
+        let processedResult = resultProcessor(result, params);
+
+        // Append DIL file path to the response for codeql_query_compile
+        if (dilFilePath) {
+          processedResult += `\n\nDIL file: ${dilFilePath}`;
+        }
 
         return {
           content: [{

server/src/lib/cli-tool-registry.ts

@@ -7,7 +7,7 @@ import { CLIToolDefinition } from '../../lib/cli-tool-registry';
 
 export const codeqlQueryCompileTool: CLIToolDefinition = {
   name: 'codeql_query_compile',
-  description: 'Compile and validate CodeQL queries',
+  description: 'Compile and validate CodeQL queries. By default, produces a .dil file containing the optimized DIL intermediate representation alongside the compilation output.',
   command: 'codeql',
   subcommand: 'query compile',
   inputSchema: {
@@ -16,6 +16,8 @@ export const codeqlQueryCompileTool: CLIToolDefinition = {
     'dump-dil': z.boolean().optional()
       .describe('Print the optimized DIL intermediate representation to standard output while compiling. Enabled by default; pass false or --no-dump-dil to disable.'),
     library: z.string().optional().describe('Path to query library'),
+    logDir: z.string().optional()
+      .describe('Directory to write the .dil file. If not provided, a unique log directory is created automatically.'),
     output: z.string().optional().describe('Output file path'),
     warnings: z.enum(['hide', 'show', 'error']).optional()
       .describe('How to handle compilation warnings'),

server/src/tools/codeql/query-compile.ts

@@ -3,7 +3,7 @@
  */
 
 import { describe, it, expect, vi, beforeEach } from 'vitest';
-import { mkdirSync, rmSync, writeFileSync } from 'fs';
+import { existsSync, mkdirSync, readFileSync, rmSync, writeFileSync } from 'fs';
 import { join } from 'path';
 import { McpServer } from '@modelcontextprotocol/sdk/server/mcp';
 import { z } from 'zod';
@@ -666,6 +666,76 @@ describe('registerCLITool handler behavior', () => {
     expect(positionalArgs).toContain('--dump-dil');
   });
 
+  it('should save DIL output to a .dil file for codeql_query_compile', async () => {
+    const definition: CLIToolDefinition = {
+      name: 'codeql_query_compile',
+      description: 'Compile query',
+      command: 'codeql',
+      subcommand: 'query compile',
+      inputSchema: {
+        query: z.string(),
+        'dump-dil': z.boolean().optional(),
+        additionalArgs: z.array(z.string()).optional()
+      }
+    };
+
+    registerCLITool(mockServer, definition);
+
+    const handler = (mockServer.registerTool as ReturnType<typeof vi.fn>).mock.calls[0][2];
+
+    const dilContent = 'DIL:\n  predicate#abc123\n    SCAN table\n    SELECT col1, col2';
+    executeCodeQLCommand.mockResolvedValueOnce({
+      stdout: dilContent,
+      stderr: '',
+      success: true
+    });
+
+    const result = await handler({ query: '/path/to/MyQuery.ql' });
+
+    // Response should contain the DIL file path
+    expect(result.content[0].text).toContain('DIL file:');
+    expect(result.content[0].text).toContain('MyQuery.dil');
+
+    // Extract the DIL file path from the response
+    const match = result.content[0].text.match(/DIL file: (.+)/);
+    expect(match).not.toBeNull();
+    const dilFilePath = match![1];
+
+    // Verify the .dil file was created with the correct content
+    expect(existsSync(dilFilePath)).toBe(true);
+    const fileContent = readFileSync(dilFilePath, 'utf8');
+    expect(fileContent).toBe(dilContent);
+  });
+
+  it('should not save DIL file when dump-dil is explicitly false for codeql_query_compile', async () => {
+    const definition: CLIToolDefinition = {
+      name: 'codeql_query_compile',
+      description: 'Compile query',
+      command: 'codeql',
+      subcommand: 'query compile',
+      inputSchema: {
+        query: z.string(),
+        'dump-dil': z.boolean().optional(),
+        additionalArgs: z.array(z.string()).optional()
+      }
+    };
+
+    registerCLITool(mockServer, definition);
+
+    const handler = (mockServer.registerTool as ReturnType<typeof vi.fn>).mock.calls[0][2];
+
+    executeCodeQLCommand.mockResolvedValueOnce({
+      stdout: 'Compilation successful',
+      stderr: '',
+      success: true
+    });
+
+    const result = await handler({ query: '/path/to/MyQuery.ql', 'dump-dil': false });
+
+    // Response should NOT contain DIL file path since dump-dil is disabled
+    expect(result.content[0].text).not.toContain('DIL file:');
+  });
+
   it('should pass format to CLI for codeql_bqrs_interpret', async () => {
     const definition: CLIToolDefinition = {
       name: 'codeql_bqrs_interpret',

server/test/src/lib/cli-tool-registry.test.ts

@@ -23,6 +23,7 @@ describe('Query Compile Tool', () => {
       expect(schema).toHaveProperty('database');
       expect(schema).toHaveProperty('dump-dil');
       expect(schema).toHaveProperty('library');
+      expect(schema).toHaveProperty('logDir');
       expect(schema).toHaveProperty('output');
       expect(schema).toHaveProperty('warnings');
       expect(schema).toHaveProperty('verbose');
@@ -35,6 +36,12 @@ describe('Query Compile Tool', () => {
       expect(dumpDil.isOptional()).toBe(true);
     });
 
+    it('should have logDir as optional string parameter', () => {
+      const logDir = codeqlQueryCompileTool.inputSchema['logDir'];
+      expect(logDir).toBeDefined();
+      expect(logDir.isOptional()).toBe(true);
+    });
+
     it('should have examples', () => {
       expect(codeqlQueryCompileTool.examples).toBeDefined();
       expect(codeqlQueryCompileTool.examples!.length).toBeGreaterThan(0);