Update d8 preemption mode to support multiple files per line. Each line is run

in its own context.  Files are separated by spaces, and will be run in order,
left to right.

Also add support for comment lines, which start with '#'.
Review URL: http://codereview.chromium.org/20319

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1306 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/d8.cc

@@ -419,6 +419,27 @@ static char* ReadChars(const char *name, int* size_out) {
 }
 
 
+static char* ReadToken(const char* data, char token) {
+  char* next = ::strchr(data, token);
+  if (next != NULL) {
+    *next = '\0';
+    return (next + 1);
+  }
+
+  return NULL;
+}
+
+
+static char* ReadLine(const char* data) {
+  return ReadToken(data, '\n');
+}
+
+
+static char* ReadWord(const char* data) {
+  return ReadToken(data, ' ');
+}
+
+
 // Reads a file into a v8 string.
 Handle<String> Shell::ReadFile(const char* name) {
   int size = 0;
@@ -473,27 +494,42 @@ void ShellThread::Run() {
   global_template->Set(String::New("version"),
                        FunctionTemplate::New(Shell::Version));
 
-  Persistent<Context> thread_context = Context::New(NULL, global_template);
-  thread_context->SetSecurityToken(Undefined());
-
-  Context::Scope context_scope(thread_context);
-
   char* ptr = const_cast<char*>(files_.start());
   while ((ptr != NULL) && (*ptr != '\0')) {
     // For each newline-separated line.
-    char *filename = ptr;
-    char* next = ::strchr(ptr, '\n');
-    if (next != NULL) {
-      *next = '\0';
-      ptr = (next + 1);
-    } else {
-      ptr = NULL;
+    char* next_line = ReadLine(ptr);
+
+    if (*ptr == '#') {
+      // Skip comment lines.
+      ptr = next_line;
+      continue;
     }
-    Handle<String> str = Shell::ReadFile(filename);
-    Shell::ExecuteString(str, String::New(filename), false, false);
-  }
 
-  thread_context.Dispose();
+    Persistent<Context> thread_context = Context::New(NULL, global_template);
+    thread_context->SetSecurityToken(Undefined());
+    Context::Scope context_scope(thread_context);
+
+    while ((ptr != NULL) && (*ptr != '\0')) {
+      char* filename = ptr;
+      ptr = ReadWord(ptr);
+
+      // Skip empty strings.
+      if (strlen(filename) == 0) {
+        break;
+      }
+
+      Handle<String> str = Shell::ReadFile(filename);
+      if (str.IsEmpty()) {
+        printf("WARNING: %s not found\n", filename);
+        break;
+      }
+
+      Shell::ExecuteString(str, String::New(filename), false, false);
+    }
+
+    thread_context.Dispose();
+    ptr = next_line;
+  }
 }