Add enough compiler support to compile empty functions on x64.

runtime/vm/code_generator_x64.h

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_CODE_GENERATOR_X64_H_
 #define VM_CODE_GENERATOR_X64_H_
 
 #ifndef VM_CODE_GENERATOR_H_
 #error Do not include code_generator_x64.h directly; use code_generator.h.
 #endif
 
@@ skipping 64 matching lines @@
   // We store the 'try index' of the block of code that we are
   // currently generating code for in the current_try_index_ variable.
   int current_try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(CodeGeneratorState);
 };
 
 
 class CodeGenerator : public AstNodeVisitor {
  public:
+  // Forward declarations.
+  class DescriptorList;

[srdjan, 2012/02/24 23:13:02]

Why the move?

[Kevin Millikin (Google), 2012/02/27 08:22:07]

Making it public for class FlowGraphCompiler.  A friend class seemed
unnecessary.

+
   CodeGenerator(Assembler* assembler, const ParsedFunction& parsed_function);
   virtual ~CodeGenerator() { }
 
   // Accessors.
   Assembler* assembler() const { return assembler_; }
 
   const ParsedFunction& parsed_function() const { return parsed_function_; }
 
   void GenerateCode();
   virtual void GenerateDeferredCode();
@@ skipping 30 matching lines @@
   virtual void CountBackwardLoop();
 
   void GenerateReturnEpilog(ReturnNode* node);
 
  private:
   // TODO(srdjan): Remove the friendship once the two compilers are properly
   // structured.
   friend class OptimizingCodeGenerator;
 
   // Forward declarations.
-  class DescriptorList;
   class HandlerList;
 
   // Return true if intrinsification was completed and no other code
   // needs to be generated.
   virtual bool TryIntrinsify() { return false; }
   virtual void GeneratePreEntryCode();
   void GenerateLegacyEntryCode();
   void GenerateEntryCode();
   void GenerateLoadVariable(Register dst, const LocalVariable& local);
   void GeneratePushVariable(const LocalVariable& variable, Register scratch);
@@ skipping 73 matching lines @@
   const ParsedFunction& parsed_function_;
   intptr_t locals_space_size_;
   CodeGeneratorState* state_;
   DescriptorList* pc_descriptors_list_;
   HandlerList* exception_handlers_list_;
   int try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(CodeGenerator);
 };
 
+
+class CodeGenerator::DescriptorList : public ZoneAllocated {

[srdjan, 2012/02/24 23:13:02]

Remove since I have moved it into code_generator.h

[Kevin Millikin (Google), 2012/02/27 08:22:07]

Thanks, done.

+ public:
+  struct PcDesc {
+    intptr_t pc_offset;        // PC offset value of the descriptor.
+    PcDescriptors::Kind kind;  // Descriptor kind (kDeopt, kOther).
+    intptr_t node_id;          // AST node id.
+    intptr_t token_index;      // Token position in source of PC.
+    intptr_t try_index;        // Try block index of PC.
+  };
+
+  DescriptorList() : list_() {
+  }
+  ~DescriptorList() { }
+
+  intptr_t Length() const {
+    return list_.length();
+  }
+
+  intptr_t PcOffset(int index) const {
+    return list_[index].pc_offset;
+  }
+  PcDescriptors::Kind Kind(int index) const {
+    return list_[index].kind;
+  }
+  intptr_t NodeId(int index) const {
+    return list_[index].node_id;
+  }
+  intptr_t TokenIndex(int index) const {
+    return list_[index].token_index;
+  }
+  intptr_t TryIndex(int index) const {
+    return list_[index].try_index;
+  }
+
+  void AddDescriptor(PcDescriptors::Kind kind,
+                     intptr_t pc_offset,
+                     intptr_t node_id,
+                     intptr_t token_index,
+                     intptr_t try_index) {
+    struct PcDesc data;
+    data.pc_offset = pc_offset;
+    data.kind = kind;
+    data.node_id = node_id;
+    data.token_index = token_index;
+    data.try_index = try_index;
+    list_.Add(data);
+  }
+
+  RawPcDescriptors* FinalizePcDescriptors(uword entry_point) {
+    intptr_t num_descriptors = Length();
+    const PcDescriptors& descriptors =
+        PcDescriptors::Handle(PcDescriptors::New(num_descriptors));
+    for (intptr_t i = 0; i < num_descriptors; i++) {
+      descriptors.AddDescriptor(i,
+                                (entry_point + PcOffset(i)),
+                                Kind(i),
+                                NodeId(i),
+                                TokenIndex(i),
+                                TryIndex(i));
+    }
+    return descriptors.raw();
+  }
+
+ private:
+  GrowableArray<struct PcDesc> list_;
+  DISALLOW_COPY_AND_ASSIGN(DescriptorList);
+};
+
+
 }  // namespace dart
 
 #endif  // VM_CODE_GENERATOR_X64_H_