src,lib: minor --debug-brk cleanup

Minor cleanup of how --debug-brk works:
* We no longer need to use command line flags to expose the debug
object.
* Do not depend on the existence of global.v8debug as a mechanism to
determine if --debug-brk was specified.
* We no longer need to set a dummy listener with --debug-brk.
PR-URL: #6599
Reviewed-By: bnoordhuis - Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: cjihrig - Colin Ihrig <cjihrig@gmail.com>

Author: ofrobots

lib/internal/bootstrap_node.js

@@ -136,7 +136,7 @@
 
 preloadModules();
 
-if(global.v8debug&&
+if(process._debugWaitConnect&&
 process.execArgv.some(function(arg){
 returnarg.match(/^--debug-brk(=[0-9]*)?$/);
 })){
@@ -149,7 +149,7 @@
 // breakpoint message on line 1.
 //
 // A better fix would be to somehow get a message from the
-// global.v8debug object about a connection, and runMain when
+// V8 debug object about a connection, and runMain when
 // that occurs. --isaacs
 
 vardebugTimeout=+process.env.NODE_DEBUG_TIMEOUT||50;

lib/module.js

@@ -4,7 +4,7 @@ const NativeModule = require('native_module');
 constutil=require('util');
 constinternalModule=require('internal/module');
 constinternalUtil=require('internal/util');
-construnInThisContext=require('vm').runInThisContext;
+constvm=require('vm');
 constassert=require('assert').ok;
 constfs=require('fs');
 constpath=require('path');
@@ -508,13 +508,13 @@ Module.prototype._compile = function(content, filename) {
 // create wrapper function
 varwrapper=Module.wrap(content);
 
-varcompiledWrapper=runInThisContext(wrapper,{
+varcompiledWrapper=vm.runInThisContext(wrapper,{
 filename: filename,
 lineOffset: 0,
 displayErrors: true
 });
 
-if(global.v8debug){
+if(process._debugWaitConnect){
 if(!resolvedArgv){
 // we enter the repl if we're not given a filename argument.
 if(process.argv[1]){
@@ -526,11 +526,9 @@ Module.prototype._compile = function(content, filename) {
 
 // Set breakpoint on module start
 if(filename===resolvedArgv){
-// Installing this dummy debug event listener tells V8 to start
-// the debugger. Without it, the setBreakPoint() fails with an
-// 'illegal access' error.
-global.v8debug.Debug.setListener(function(){});
-global.v8debug.Debug.setBreakPoint(compiledWrapper,0,0);
+deleteprocess._debugWaitConnect;
+constDebug=vm.runInDebugContext('Debug');
+Debug.setBreakPoint(compiledWrapper,0,0);
 }
 }
 vardirname=path.dirname(filename);

src/node.cc

@@ -3179,6 +3179,11 @@ void SetupProcessObject(Environment* env,
 READONLY_PROPERTY(process, "traceDeprecation", True(env->isolate()));
  }
 
+// --debug-brk
+if (debug_wait_connect) {
+READONLY_PROPERTY(process, "_debugWaitConnect", True(env->isolate()));
+ }
+
 // --security-revert flags
 #defineV(code, _, __) \
 do { \
@@ -4087,11 +4092,6 @@ void Init(int* argc,
 exit(9);
  }
 
-if (debug_wait_connect) {
-constchar expose_debug_as[] = "--expose_debug_as=v8debug";
-V8::SetFlagsFromString(expose_debug_as, sizeof(expose_debug_as) - 1);
- }
-
 // Unconditionally force typed arrays to allocate outside the v8 heap. This
 // is to prevent memory pointers from being moved around that are returned by
 // Buffer::Data().