Simplify the desugaring of catch clauses.

runtime/vm/parser.h

Index: runtime/vm/parser.h
diff --git a/runtime/vm/parser.h b/runtime/vm/parser.h
index ccdff42f6e260124d3bb5de087a2041e8e116b86..5c04b687222b92cb731f0d4df9b6519d54f16543 100644
--- a/runtime/vm/parser.h
+++ b/runtime/vm/parser.h
@@ -7,29 +7,32 @@
 
 #include "include/dart_api.h"
 
+#include "platform/assert.h"

[Kevin Millikin (Google), 2013/11/08 11:03:56]

This file uses the ASSERT macro and so needs the definition.

+#include "platform/globals.h"

[Kevin Millikin (Google), 2013/11/08 11:03:56]

This file uses the PRINTF_ATTRIBUTE macro and so needs the definition.

 #include "lib/invocation_mirror.h"
+#include "vm/allocation.h"

[Kevin Millikin (Google), 2013/11/08 11:03:56]

This file uses base classes ZoneAllocated and ValueObject, so it needs their
definitions.

 #include "vm/ast.h"

[Kevin Millikin (Google), 2013/11/08 11:03:56]

Note that this file doesn't actually need ast.h, just about a dozen or so
forward definitions.  It seems more convenient just to keep this here even
though it potentially creates implicit dependencies elsewhere.

 #include "vm/class_finalizer.h"
 #include "vm/compiler_stats.h"
-#include "vm/scanner.h"

[Kevin Millikin (Google), 2013/11/08 11:03:56]

scanner.h declares a single type Scanner, which is not used here.  No reason to
include it.

+#include "vm/object.h"

[Kevin Millikin (Google), 2013/11/08 11:03:56]

This file needs a long list of types from object.h.  Some of them were forward
declared already, but by no means all.  (I think it only needs forward
declarations, but I opted for include for the same reason we include ast.h for
consistency.)

+#include "vm/raw_object.h"

[Kevin Millikin (Google), 2013/11/08 11:03:56]

Needs types from raw_object.h.  Probably could do with a bunch of forward
declarations.

+#include "vm/token.h"

[Kevin Millikin (Google), 2013/11/08 11:03:56]

This file needs the definition of Token::Kind.

 
 namespace dart {
 
 // Forward declarations.
 class ArgumentsDescriptor;
-class Function;

[Kevin Millikin (Google), 2013/11/08 11:03:56]

Not needed if we include object.h.  Otherwise, we can try to forward *all* the
classes we use from object.h, but it seems random to just have one or two.

 class Isolate;
-class LiteralToken;

[Kevin Millikin (Google), 2013/11/08 11:03:56]

Not needed if we include token.h (which we need to include anyway).

-class Script;
-class TokenStream;
+class LocalScope;

[Kevin Millikin (Google), 2013/11/08 11:03:56]

This class and the next two need forward declarations.

+class LocalVariable;
+class SourceLabel;
+template <typename T> class GrowableArray;

[Kevin Millikin (Google), 2013/11/08 11:03:56]

Likewise.

 
 struct TopLevel;
 class ClassDesc;
 struct MemberDesc;
 struct ParamList;
 struct QualIdent;
-struct CatchParamDesc;

[Kevin Millikin (Google), 2013/11/08 11:03:56]

I've moved the only helper that uses this type to a static function in the .cc
file, so this type does not need to be part of the Parser's API.

-struct FieldInitExpression;

[Kevin Millikin (Google), 2013/11/08 11:03:56]

This is just dead.  There is no definition and no uses.

 
 // The class ParsedFunction holds the result of parsing a function.
 class ParsedFunction : public ZoneAllocated {
@@ -506,9 +509,12 @@ class Parser : public ValueObject {
   AstNode* ParseSwitchStatement(String* label_name);
 
   // try/catch/finally parsing.
-  void AddCatchParamsToScope(const CatchParamDesc& exception_param,
-                             const CatchParamDesc& stack_trace_param,
-                             LocalScope* scope);
+  // Parse a catch clause (and recursively all the following ones).
+  AstNode* ParseCatchClause(intptr_t handler_pos,
+                            LocalVariable* exception_var,
+                            LocalVariable* stack_trace_var,
+                            const GrowableObjectArray& handler_types,
+                            bool* needs_stack_trace);
   // Parse finally block and create an AST for it.
   SequenceNode* ParseFinallyBlock();
   // Adds try block to the list of try blocks seen so far.