MCP GDB Server

Instructions

Implementation Reference

• src/index.ts:1112-1154 (handler)

  Handler function that processes the gdb_info_registers tool call. Extracts sessionId and optional register, validates session, executes the GDB 'info registers' command (with optional register), and returns formatted output or error.
  private async handleGdbInfoRegisters(args: any) { const { sessionId, register } = args; if (!activeSessions.has(sessionId)) { return { content: [ { type: 'text', text: `No active GDB session with ID: ${sessionId}` } ], isError: true }; } const session = activeSessions.get(sessionId)!; try { // Build info registers command, optionally with specific register const command = register ? `info registers ${register}` : `info registers`; const output = await this.executeGdbCommand(session, command); return { content: [ { type: 'text', text: `Register info${register ? ` for ${register}` : ''}:\n\n${output}` } ] }; } catch (error) { const errorMessage = error instanceof Error ? error.message : String(error); return { content: [ { type: 'text', text: `Failed to get register info: ${errorMessage}` } ], isError: true }; } }
• src/index.ts:338-351 (schema)

  Input schema defining the parameters for the gdb_info_registers tool: required sessionId (string) and optional register (string).
  inputSchema: { type: 'object', properties: { sessionId: { type: 'string', description: 'GDB session ID' }, register: { type: 'string', description: 'Specific register to display (optional)' } }, required: ['sessionId'] }
• src/index.ts:335-352 (registration)

  Tool registration in the list returned by ListToolsRequestSchema, specifying name, description, and input schema.
  { name: 'gdb_info_registers', description: 'Display registers', inputSchema: { type: 'object', properties: { sessionId: { type: 'string', description: 'GDB session ID' }, register: { type: 'string', description: 'Specific register to display (optional)' } }, required: ['sessionId'] } }
• src/index.ts:389-390 (registration)

  Switch case in CallToolRequestSchema handler that routes calls to the gdb_info_registers handler function.
  case 'gdb_info_registers': return await this.handleGdbInfoRegisters(request.params.arguments);
• src/index.ts:1159-1217 (helper)

  Helper function used by the handler to execute arbitrary GDB commands via stdin/stdout, waiting for response completion with timeout and error handling.
  private executeGdbCommand(session: GdbSession, command: string): Promise<string> { return new Promise<string>((resolve, reject) => { if (!session.ready) { reject(new Error('GDB session is not ready')); return; } // Write command to GDB's stdin if (session.process.stdin) { session.process.stdin.write(command + '\n'); } else { reject(new Error('GDB stdin is not available')); return; } let output = ''; let responseComplete = false; // Create a one-time event handler for GDB output const onLine = (line: string) => { output += line + '\n'; // Check if this line indicates the end of the GDB response if (line.includes('(gdb)') || line.includes('^done') || line.includes('^error')) { responseComplete = true; // If we've received the complete response, resolve the promise if (responseComplete) { // Remove the listener to avoid memory leaks session.rl.removeListener('line', onLine); resolve(output); } } }; // Add the line handler to the readline interface session.rl.on('line', onLine); // Set a timeout to prevent hanging const timeout = setTimeout(() => { session.rl.removeListener('line', onLine); reject(new Error('GDB command timed out')); }, 10000); // 10 second timeout // Handle GDB errors const errorHandler = (data: Buffer) => { const errorText = data.toString(); output += `[stderr] ${errorText}\n`; }; // Add error handler if (session.process.stderr) { session.process.stderr.once('data', errorHandler); } // Clean up event handlers when the timeout expires timeout.unref(); }); }