asmimproved-dbgmits/src/dbgmits.ts

Provides the ability to control GDB and LLDB programmatically via GDB/MI.

// Copyright (c) 2015 Vadim Macagon
// MIT License, see LICENSE file for full terms.

import DebugSession from './debug_session';
import GDBDebugSession from './gdb_debug_session';
import { spawn, ChildProcess } from 'child_process';
import * as os from 'os';
import * as path from 'path';
import * as stream from 'stream';

function setProcessEnvironment(): void {
  // HACK for LLDB on Windows (where users have to build their own Python)
  if (os.platform() === 'win32') {
    if (process.env['LLDB_PYTHON_SRC'] === undefined) {
      throw new Error(
        'LLDB_PYTHON_SRC environment variable is not set. It must be set to the source directory ' +
        'of the Python version used in the LLDB build.'
      );
    }
    if (process.env['LLVM_SRC_BUILD'] === undefined) {
      throw new Error(
        'LLVM_SRC_BUILD environment variable is not set. It must be set to the LLVM build output ' +
        'directory.'
      );
    }
    process.env['PATH'] =
      process.env['PATH'] + ';' + path.join(process.env['LLDB_PYTHON_SRC'], 'PCbuild');
    var pythonPath =
      path.join(process.env['LLDB_PYTHON_SRC'], 'Lib') + ';' +
      path.join(process.env['LLVM_SRC_BUILD'], 'lib\\site-packages');

    if (process.env['PYTHONPATH']) {
      process.env['PYTHONPATH'] = process.env['PYTHONPATH'] + ';' + pythonPath;
    } else {
      process.env['PYTHONPATH'] = pythonPath;
    }
  }
}

export enum DebuggerType {
  GDB,
  LLDB
}

/**
 * Starts a new debugging session and spawns the debbuger process.
 *
 * Once the debug session has outlived its usefulness call [[DebugSession.end]] to ensure proper
 * cleanup.
 *
 * @param debuggerFilename Full path to debugger executable, defaults to either `lldb-mi` or `gdb`
 *                         (based on [[debuggerType]]).
 * @returns A new debug session, or null if a new session couldn't be started.
 */
export function startDebugSession(debuggerType: DebuggerType, debuggerFilename?: string): DebugSession {
  let debuggerArgs: string[];

  switch (debuggerType) {
    case DebuggerType.LLDB:
      setProcessEnvironment();
      if (!debuggerFilename) {
        // lldb-mi.exe should be on the PATH
        debuggerFilename = 'lldb-mi';
      }
      debuggerArgs = ['--interpreter'];
      break;

    case DebuggerType.GDB:
      if (!debuggerFilename) {
        debuggerFilename = 'gdb';
      }
      debuggerArgs = ['--interpreter', 'mi'];
      break;

    default:
      throw new Error('Unknown debugger type!');
  }

  const debuggerProcess: ChildProcess = spawn(debuggerFilename, debuggerArgs);
  let debugSession: DebugSession = null;
  if (debuggerProcess) {
    if (debuggerType === DebuggerType.GDB) {
      debugSession = new GDBDebugSession(debuggerProcess.stdout, debuggerProcess.stdin);
    } else {
      debugSession = new DebugSession(debuggerProcess.stdout, debuggerProcess.stdin);
    }
    if (debugSession) {
      debuggerProcess.once('exit',
        (code: number, signal: string) => { debugSession.end(false); }
      );
    }
  }
  return debugSession;
};

export function startGDBDebugSessionFromExistingProcess(stdout: stream.Readable, stdin: stream.Writable, exitSubject: any) {
  let debugSession: DebugSession = null;
  debugSession = new DebugSession(stdout, stdin);
  exitSubject.then(() => {
    debugSession.end(false);
  });
  return debugSession;
}