Add ability for Function to generate source

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 8ba182a30b55d34f06cab4fbc87dfe6df5d1c068..ac251452b19e38ee3daaffc6689360b7f793a690 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -5443,6 +5443,13 @@ RawString* Function::QualifiedUserVisibleName() const {
 }
 
 
+RawString* Function::GenerateSource() {

[hausner, 2013/11/05 22:30:05]

I suggest making this a bit more smart. If we do have the source code for the
function, we should return the original source code, not synthesized sources.
Maybe add a function to class Script that returns either the actual source code
between two tokens (rounded to beginning and end of line possibly) or generated
source code if there is no source code available.

+  const Script& func_script = Script::Handle(script());
+  const TokenStream& token_stream = TokenStream::Handle(func_script.tokens());
+  return token_stream.GenerateSource(token_pos(), end_token_pos());
+}
+
+
 // Construct fingerprint from token stream. The token stream contains also
 // arguments.
 int32_t Function::SourceFingerprint() const {
@@ -6250,8 +6257,9 @@ void TokenStream::SetPrivateKey(const String& value) const {
 }
 
 
-RawString* TokenStream::GenerateSource() const {
-  Iterator iterator(*this, 0, Iterator::kAllTokens);
+RawString* TokenStream::GenerateSource(intptr_t start_tok_pos,
+                                       intptr_t end_tok_pos) const {
+  Iterator iterator(*this, start_tok_pos, Iterator::kAllTokens);
   const ExternalTypedData& data = ExternalTypedData::Handle(GetStream());
   const GrowableObjectArray& literals =
       GrowableObjectArray::Handle(GrowableObjectArray::New(data.Length()));
@@ -6267,6 +6275,10 @@ RawString* TokenStream::GenerateSource() const {
   int indent = 0;
 
   while (curr != Token::kEOS) {
+    if ((end_tok_pos > 0) && (iterator.CurrentPosition() > end_tok_pos)) {

[hausner, 2013/11/05 22:30:05]

Is end_token_pos inclusive or exclusive? Typically we use exclusive end
positions. In that case, the comparison should be >=. In any case, maybe a
comment in the header file would be good to clarify. 

+      // We've reached the end of the token stream we want.
+      break;
+    }
     // Remember current values for this token.
     obj = iterator.CurrentToken();
     literal = iterator.MakeLiteralToken(obj);