[Courgette] AssemblyProgram: Serialize data to single raw buffer, instead of storing pointer of obj…

courgette/assembly_program.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_ASSEMBLY_PROGRAM_H_
 #define COURGETTE_ASSEMBLY_PROGRAM_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <map>
 #include <memory>
 #include <set>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/memory/free_deleter.h"
 #include "courgette/courgette.h"
 #include "courgette/image_utils.h"
 #include "courgette/label_manager.h"
 #include "courgette/memory_allocator.h"
 
 namespace courgette {
 
 class EncodedProgram;
 
+using serialized_size_t = uint32_t;
+
+// Raw data array for AssemblyData seralization.
+using AssemblyRawDataVector = NoThrowBuffer<uint8_t>;
+
 // Opcodes of simple assembly language
-enum OP {
-  ORIGIN,         // ORIGIN <rva> - set current address for assembly.
-  MAKEPERELOCS,   // Generates a base relocation table.
-  MAKEELFRELOCS,  // Generates a base relocation table.
-  DEFBYTE,        // DEFBYTE <value> - emit a byte literal.
-  REL32,          // REL32 <label> - emit a rel32 encoded reference to 'label'.
-  ABS32,          // ABS32 <label> - emit an abs32 encoded reference to 'label'.
-  REL32ARM,       // REL32ARM <c_op> <label> - arm-specific rel32 reference
-  MAKEELFARMRELOCS,  // Generates a base relocation table.
-  DEFBYTES,       // Emits any number of byte literals
-  ABS64,          // ABS64 <label> - emit an abs64 encoded reference to 'label'.
-  LAST_OP
-};
-
-// Base class for instructions.  Because we have so many instructions we want to
-// keep them as small as possible.  For this reason we avoid virtual functions.
-class Instruction {
+class AssemblyOp {
  public:
-  OP op() const { return static_cast<OP>(op_); }
-
- protected:
-  explicit Instruction(OP op) : op_(op), info_(0) {}
-  Instruction(OP op, unsigned int info) : op_(op), info_(info) {}
-
-  uint32_t op_ : 4;     // A few bits to store the OP code.
-  uint32_t info_ : 28;  // Remaining bits in first word available to subclass.
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(Instruction);
+  // Any change in this Update |kOpSize|
+  enum OP : uint8_t {
+    ORIGIN,         // ORIGIN <rva>: Sets current address for assembly.
+    MAKEPERELOCS,   // Generates a base relocation table.
+    MAKEELFRELOCS,  // Generates a base relocation table.
+    SINGLEBYTE,     // SINGLEBYTE <value>: Emits a byte literal.
+    REL32,          // REL32 <label>: Emits a rel32 encoded reference to Label.
+    ABS32,          // ABS32 <label>: Emits an abs32 encoded reference to Label.
+    REL32ARM,       // REL32ARM <c_op> <label>: ARM-specific rel32 reference.
+    MAKEELFARMRELOCS,  // Generates a base relocation table.
+    MULTIPLEBYTES,     // Emits any number of byte literals.
+    ABS64,  // ABS64 <label>: Emits an abs64 encoded reference to Label.
+    NUM_OP
+  };
 };
 
 // An interface to receive emitted instructions parsed from an executable.
 class InstructionReceptor {
  public:
   InstructionReceptor() = default;
   virtual ~InstructionReceptor() = default;
 
   // Generates an entire base relocation table.
   virtual CheckBool EmitPeRelocs() = 0;
@@ skipping 47 matching lines @@
 // The optional step is to modify the AssemblyProgram.  One form of modification
 // is to assign indexes in such a way as to make the EncodedProgram for this
 // AssemblyProgram look more like the EncodedProgram for some other
 // AssemblyProgram.  The modification process should call UnassignIndexes, do
 // its own assignment, and then call AssignRemainingIndexes to ensure all
 // indexes are assigned.
 
 class AssemblyProgram {
  public:
   using LabelHandler = base::Callback<void(Label*)>;
-  using LabelHandlerMap = std::map<OP, LabelHandler>;
+  using LabelHandlerMap = std::map<AssemblyOp::OP, LabelHandler>;
 
   // A callback for GenerateInstructions() to emit instructions. The first
   // argument (AssemblyProgram*) is provided for Label-related feature access.
   // The second argument (InstructionReceptor*) is a receptor for instructions.
   // The callback (which gets called in 2 passes) should return true on success,
   // and false otherwise.
   using InstructionGenerator =
       base::Callback<CheckBool(AssemblyProgram*, InstructionReceptor*)>;
 
   explicit AssemblyProgram(ExecutableType kind);
-  ~AssemblyProgram();
+  ~AssemblyProgram() = default;
 
   ExecutableType kind() const { return kind_; }
 
   void set_image_base(uint64_t image_base) { image_base_ = image_base; }
 
   // Traverses RVAs in |abs32_visitor| and |rel32_visitor| to precompute Labels.
   void PrecomputeLabels(RvaVisitor* abs32_visitor, RvaVisitor* rel32_visitor);
 
   // Removes underused Labels. Thresholds used (0 = no trimming) is
   // architecture-dependent.
   void TrimLabels();
 
   void UnassignIndexes();
   void DefaultAssignIndexes();
   void AssignRemainingIndexes();
 
   // Looks up abs32 label. Returns null if none found.
   Label* FindAbs32Label(RVA rva);
 
   // Looks up rel32 label. Returns null if none found.
   Label* FindRel32Label(RVA rva);
 
   std::unique_ptr<EncodedProgram> Encode() const;
 
-  // For each |instruction| in |instructions_|, looks up its opcode from
-  // |handler_map| for a handler. If a handler exists, invoke it by passing the
-  // |instruction|'s label. We assume that |handler_map| has correct keys, i.e.,
-  // opcodes for an instruction that have label.
+  // For each instruction in |raw_data_|, looks up its opcode from |handler_map|
+  // for a handler. If a handler exists, invoke it by passing the instruction's
+  // label. We assume that |handler_map| has correct keys, i.e., opcodes for an
+  // instruction that have label.
   void HandleInstructionLabels(const LabelHandlerMap& handler_map) const;
 
   // Calls |gen| in 2 passes to emit instructions. In pass 1 we provide a
   // receptor to count space requirement. In pass 2 we provide a receptor to
-  // store instructions.
+  // store instructions. This function can only be called once per instance.
   CheckBool GenerateInstructions(const InstructionGenerator& gen);
 
-  // TODO(huangs): Implement these in InstructionStoreReceptor.
-  // Instructions will be assembled in the order they are emitted.
-
-  // Generates an entire base relocation table.
-  CheckBool EmitPeRelocs() WARN_UNUSED_RESULT;
-
-  // Generates an ELF style relocation table for X86.
-  CheckBool EmitElfRelocation() WARN_UNUSED_RESULT;
-
-  // Generates an ELF style relocation table for ARM.
-  CheckBool EmitElfARMRelocation() WARN_UNUSED_RESULT;
-
-  // Following instruction will be assembled at address 'rva'.
-  CheckBool EmitOrigin(RVA rva) WARN_UNUSED_RESULT;
-
-  // Generates a single byte of data or machine instruction.
-  CheckBool EmitSingleByte(uint8_t byte) WARN_UNUSED_RESULT;
-
-  // Generates multiple bytes of data or machine instructions.
-  CheckBool EmitMultipleBytes(const uint8_t* bytes,
-                              size_t len) WARN_UNUSED_RESULT;
-
-  // Generates a 4-byte relative reference to address of 'label'.
-  CheckBool EmitRel32(Label* label) WARN_UNUSED_RESULT;
-
-  // Generates a 4-byte relative reference to address of 'label' for ARM.
-  CheckBool EmitRel32ARM(uint16_t op,
-                         Label* label,
-                         const uint8_t* arm_op,
-                         uint16_t op_size) WARN_UNUSED_RESULT;
-
-  // Generates a 4-byte absolute reference to address of 'label'.
-  CheckBool EmitAbs32(Label* label) WARN_UNUSED_RESULT;
-
-  // Generates an 8-byte absolute reference to address of 'label'.
-  CheckBool EmitAbs64(Label* label) WARN_UNUSED_RESULT;
-
  private:
-  using InstructionVector = NoThrowBuffer<Instruction*>;
-
-  using ScopedInstruction =
-      std::unique_ptr<Instruction, UncheckedDeleter<Instruction>>;
-
   ExecutableType kind_;
 
-  CheckBool Emit(ScopedInstruction instruction) WARN_UNUSED_RESULT;
-  CheckBool EmitShared(Instruction* instruction) WARN_UNUSED_RESULT;
-
   static const int kLabelLowerLimit;
 
   // Looks up a label or creates a new one.  Might return NULL.
   Label* FindLabel(RVA rva, RVAToLabel* labels);
 
   // Helper methods for the public versions.
   static void UnassignIndexes(RVAToLabel* labels);
   static void DefaultAssignIndexes(RVAToLabel* labels);
   static void AssignRemainingIndexes(RVAToLabel* labels);
 
-  // Sharing instructions that emit a single byte saves a lot of space.
-  Instruction* GetByteInstruction(uint8_t byte);
-  std::unique_ptr<Instruction* [], base::FreeDeleter> byte_instruction_cache_;
-
-  uint64_t image_base_;  // Desired or mandated base address of image.
-
-  InstructionVector instructions_;  // All the instructions in program.
+  uint64_t image_base_ = 0;  // Desired or mandated base address of image.
 
   // Storage and lookup of Labels associated with target addresses. We use
   // separate abs32 and rel32 labels.
   LabelManager abs32_label_manager_;
   LabelManager rel32_label_manager_;
 
+  // Container of serialized instruction data.
+  AssemblyRawDataVector instruction_raw_data_;
+
   DISALLOW_COPY_AND_ASSIGN(AssemblyProgram);
 };
 
 // Converts |program| into encoded form, returning it as |*output|.
 // Returns C_OK if succeeded, otherwise returns an error status and sets
 // |*output| to null.
 Status Encode(const AssemblyProgram& program,
               std::unique_ptr<EncodedProgram>* output);
 
 }  // namespace courgette
 
 #endif  // COURGETTE_ASSEMBLY_PROGRAM_H_