[parser] Refactor of Parse*Statement*, part 7

src/parsing/preparser.h

Index: src/parsing/preparser.h
diff --git a/src/parsing/preparser.h b/src/parsing/preparser.h
index ddc74c53180867f6fb679e7aeaffe5ce90ca0673..d8c04fe8daccd41d0d0695f604a58eab74aff1de 100644
--- a/src/parsing/preparser.h
+++ b/src/parsing/preparser.h
@@ -825,7 +825,6 @@ class PreParser : public ParserBase<PreParser> {
   Statement ParseClassDeclaration(ZoneList<const AstRawString*>* names,
                                   bool default_export, bool* ok);
   Statement ParseForStatement(ZoneList<const AstRawString*>* labels, bool* ok);
-  Statement ParseTryStatement(bool* ok);
   Expression ParseConditionalExpression(bool accept_IN, bool* ok);
   Expression ParseObjectLiteral(bool* ok);
 
@@ -946,6 +945,22 @@ class PreParser : public ParserBase<PreParser> {
       PreParserStatementList cases, Scope* scope) {
     return PreParserStatement::Default();
   }
+  V8_INLINE void RewriteCatchPattern(CatchInfo* catch_info, bool* ok) {}
+  V8_INLINE void ValidateCatchBlock(const CatchInfo& catch_info, bool* ok) {}
+  V8_INLINE PreParserStatement RewriteTryStatement(
+      PreParserStatement try_block, PreParserStatement catch_block,
+      PreParserStatement finally_block, const CatchInfo& catch_info, int pos,
+      bool* ok) {

[marja, 2016/09/14 10:06:59]

Now this code is in both Parser and PreParser; what's the reason for not writing
it in a unified manner?

[nickie, 2016/09/14 10:19:09]

Well, for some weird reason, in the two implementations this code is guarded by
different conditions.  It won't be easy to keep the same behavior and make the
code look handsome.  If it comes to changing the behavior, I'm not sure what
exactly this does.

[marja, 2016/09/14 11:00:27]

I think that should get figured out before landing this...

If it turns out that there was really a behavioral difference, i.e., Parser was
producing an error where PreParser wasn't, or the other way around, I think that
should be fixed as a side product of this unification. That would also be a good
opportunity to add the corresponding test-parsing unification test.

So let's see:

In PreParser:

if (FLAG_harmony_explicit_tailcalls && catch_block_exists &&
    tail_call_expressions_in_catch_block.has_explicit_tail_calls()) {

...

In Parser:

if (FLAG_harmony_explicit_tailcalls &&
    tail_call_expressions_in_catch_block.has_explicit_tail_calls()) {


I think they are the same; there's no way that
tail_call_expressions_in_catch_block has something and  catch_block_exists
wouldn't be set to true.

[nickie, 2016/09/14 11:43:08]

Done.  (As discussed offline.)

+    if (FLAG_harmony_explicit_tailcalls && !catch_block.IsNullStatement() &&
+        catch_info.tail_call_expressions.has_explicit_tail_calls()) {
+      // TODO(ishell): update chapter number.
+      // ES8 XX.YY.ZZ
+      ReportMessageAt(catch_info.tail_call_expressions.location(),
+                      MessageTemplate::kUnexpectedTailCallInCatchBlock);
+      *ok = false;
+    }
+    return PreParserStatement::Default();
+  }
 
   V8_INLINE PreParserExpression RewriteDoExpression(PreParserStatement body,
                                                     int pos, bool* ok) {
@@ -1180,7 +1195,7 @@ class PreParser : public ParserBase<PreParser> {
   }
 
   V8_INLINE static PreParserStatement NullStatement() {
-    return PreParserStatement::Default();
+    return PreParserStatement::Null();
   }
 
   V8_INLINE bool IsNullStatement(PreParserStatement stmt) {
@@ -1192,7 +1207,7 @@ class PreParser : public ParserBase<PreParser> {
   }
 
   V8_INLINE static PreParserStatement NullBlock() {
-    return PreParserStatement::Default();
+    return PreParserStatement::Null();
   }
 
   V8_INLINE PreParserIdentifier EmptyIdentifierString() const {