[Courgette] Refactor: Unify Disassembler::Disassemble() and instantiate AssemblyProgram there.

courgette/disassembler.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COURGETTE_DISASSEMBLER_H_
 #define COURGETTE_DISASSEMBLER_H_
 
 #include <stdint.h>
 
+#include <memory>
 #include <vector>
 
 #include "base/macros.h"
 #include "courgette/courgette.h"
 #include "courgette/image_utils.h"
+#include "courgette/instruction_utils.h"
 
 namespace courgette {
 
 class AssemblyProgram;
 
 class Disassembler : public AddressTranslator {
  public:
   // Visitor/adaptor to translate RVA to target RVA for abs32.
   class RvaVisitor_Abs32 : public VectorRvaVisitor<RVA> {
    public:
@@ skipping 34 matching lines @@
   const uint8_t* FileOffsetToPointer(FileOffset file_offset) const override;
   const uint8_t* RVAToPointer(RVA rva) const override;
   RVA PointerToTargetRVA(const uint8_t* p) const override = 0;
 
   virtual ExecutableType kind() const = 0;
 
   // Returns the preferred image base address. Using uint64_t to accommodate the
   // general case of 64-bit architectures.
   virtual uint64_t image_base() const = 0;
 
+  // Extracts and stores locations of abs32 references from the image file.
+  virtual bool ExtractAbs32Locations() = 0;
+
+  // Extracts and stores locations of rel32 references from the image file.
+  virtual bool ExtractRel32Locations() = 0;
+
   // Returns a caller-owned new RvaVisitor to iterate through abs32 target RVAs.
   virtual RvaVisitor* CreateAbs32TargetRvaVisitor() = 0;
 
   // Returns a caller-owned new RvaVisitor to iterate through rel32 target RVAs.
   virtual RvaVisitor* CreateRel32TargetRvaVisitor() = 0;
 
   // Removes unused rel32 locations (architecture-specific). This is needed
   // because we may remove rel32 Labels along the way. As a result the matching
-  // matching rel32 addresses become unused. Removing them saves space.
+  // rel32 addresses become unused. Removing them saves space.
   virtual void RemoveUnusedRel32Locations(AssemblyProgram* program) = 0;
 
-  // Returns true if the buffer appears to be a valid executable of the expected
-  // type, and false otherwise. This needs not be called before Disassemble().
+  // Extracts structural data from the main image. Returns true if the image
+  // appears to be a valid executable of the expected type, or false otherwise.
+  // This needs to be called before Disassemble().
   virtual bool ParseHeader() = 0;
 
-  // Disassembles the item passed to the factory method into the output
-  // parameter 'program'.
-  virtual bool Disassemble(AssemblyProgram* program) = 0;
+  // Extracts and stores references from the main image. Returns a new
+  // AssemblyProgram initialized using data parsed from the main image, or null
+  // on failure.
+  std::unique_ptr<AssemblyProgram> Disassemble();
 
   // ok() may always be called but returns true only after ParseHeader()
   // succeeds.
   bool ok() const { return failure_reason_ == nullptr; }
 
   // Returns the length of the image. May reduce after ParseHeader().
   size_t length() const { return length_; }
   const uint8_t* start() const { return start_; }
   const uint8_t* end() const { return end_; }
 
  protected:
   Disassembler(const uint8_t* start, size_t length);
 
   bool Good();
   bool Bad(const char *reason);
 
   // Returns true if the array lies within our memory region.
   bool IsArrayInBounds(size_t offset, size_t elements, size_t element_size) {
     return offset <= length() && elements <= (length() - offset) / element_size;
   }
 
   // Computes and stores all Labels before scanning program bytes.
   void PrecomputeLabels(AssemblyProgram* program);
 
   // Reduce the length of the image in memory. Does not actually free
   // (or realloc) any memory. Usually only called via ParseHeader().
   void ReduceLength(size_t reduced_length);
 
+  // Returns a generator that emits instructions to a given receptor. |program|
+  // is required as helper.
+  virtual InstructionGenerator GetInstructionGenerator(
+      AssemblyProgram* program) = 0;
+
  private:
   const char* failure_reason_;
 
   //
   // Basic information that is always valid after construction, although
   // ParseHeader() may shorten |length_| if the executable is shorter than the
   // total data.
   //
   size_t length_;         // In current memory.
   const uint8_t* start_;  // In current memory, base for 'file offsets'.
   const uint8_t* end_;    // In current memory.
 
   DISALLOW_COPY_AND_ASSIGN(Disassembler);
 };
 
 }  // namespace courgette
 
 #endif  // COURGETTE_DISASSEMBLER_H_