Move InitLineEnds and GetLineNumber to handles.cc to avoid...

src/handles.cc

Index: src/handles.cc
===================================================================
--- src/handles.cc	(revision 1480)
+++ src/handles.cc	(working copy)
@@ -186,9 +186,7 @@
 
 
 void FlattenString(Handle<String> string) {
-  StringShape shape(*string);
-  if (string->IsFlat(shape)) return;
-  CALL_HEAP_FUNCTION_VOID(string->TryFlatten(shape));
+  CALL_HEAP_FUNCTION_VOID(string->TryFlattenIfNotFlat(StringShape(*string)));

[Mads Ager (chromium), 2009/03/10 19:26:58]

I think this change makes the code much clearer (and I think we should get rid
of StringShape all together - we have talked about doing that for a while now).

I think that this code was safe the way it was though.  The only strings that
change their shape during GC are ConsStrings that have an emtpy right-hand side.
 For those strings, string->IsFlat(shape) will return true and we will bail out
before the part that can cause a GC.  For other strings, the shape is still
valid after a GC.

Anyway, this is a good change!

   ASSERT(string->IsFlat(StringShape(*string)));
 }
 
@@ -343,6 +341,78 @@
 }
 
 
+// Init line_ends array with code positions of line ends inside script
+// source.
+void InitScriptLineEnds(Handle<Script> script) {
+  if (!script->line_ends()->IsUndefined()) return;
+
+  if (!script->source()->IsString()) {
+    ASSERT(script->source()->IsUndefined());
+    script->set_line_ends(*(Factory::NewJSArray(0)));
+    ASSERT(script->line_ends()->IsJSArray());
+    return;
+  }
+
+  Handle<String> src(String::cast(script->source()));
+  const int src_len = src->length();
+  Handle<String> new_line = Factory::NewStringFromAscii(CStrVector("\n"));
+
+  // Pass 1: Identify line count.
+  int line_count = 0;
+  int position = 0;
+  while (position != -1 && position < src_len) {
+    position = Runtime::StringMatch(src, new_line, position);
+    if (position != -1) {
+      position++;
+    }
+    // Even if the last line misses a line end, it is counted.
+    line_count++;
+  }
+
+  // Pass 2: Fill in line ends positions
+  Handle<FixedArray> array = Factory::NewFixedArray(line_count);
+  int array_index = 0;
+  position = 0;
+  while (position != -1 && position < src_len) {
+    position = Runtime::StringMatch(src, new_line, position);
+    // If the script does not end with a line ending add the final end
+    // position as just past the last line ending.
+    array->set(array_index++,
+               Smi::FromInt(position != -1 ? position++ : src_len));
+  }
+  ASSERT(array_index == line_count);
+
+  Handle<JSArray> object = Factory::NewJSArrayWithElements(array);
+  script->set_line_ends(*object);
+  ASSERT(script->line_ends()->IsJSArray());
+}
+
+
+// Convert code position into line number.
+int GetScriptLineNumber(Handle<Script> script, int code_pos) {
+  InitScriptLineEnds(script);
+  AssertNoAllocation no_allocation;
+  JSArray* line_ends_array = JSArray::cast(script->line_ends());
+  const int line_ends_len = (Smi::cast(line_ends_array->length()))->value();
+
+  int line = -1;
+  if (line_ends_len > 0 &&
+      code_pos <= (Smi::cast(line_ends_array->GetElement(0)))->value()) {
+    line = 0;
+  } else {
+    for (int i = 1; i < line_ends_len; ++i) {
+      if ((Smi::cast(line_ends_array->GetElement(i - 1)))->value() < code_pos &&
+          code_pos <= (Smi::cast(line_ends_array->GetElement(i)))->value()) {
+        line = i;
+        break;
+      }
+    }
+  }
+
+  return line != -1 ? line + script->line_offset()->value() : line;
+}
+
+
 // Compute the property keys from the interceptor.
 v8::Handle<v8::Array> GetKeysForNamedInterceptor(Handle<JSObject> receiver,
                                                  Handle<JSObject> object) {