[Courgette] Using LabelManager to reduce Courgette-apply peak RAM by 25%.

courgette/encoded_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_ENCODED_PROGRAM_H_
 #define COURGETTE_ENCODED_PROGRAM_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 32 matching lines @@
 class EncodedProgram {
  public:
   EncodedProgram();
   ~EncodedProgram();
 
   // Generating an EncodedProgram:
   //
   // (1) The image base can be specified at any time.
   void set_image_base(uint64_t base) { image_base_ = base; }
 
-  // (2) Address tables and indexes defined first.
-  CheckBool DefineLabels(const RVAToLabel& abs32_labels,
-                         const RVAToLabel& rel32_labels) WARN_UNUSED_RESULT;
+  // (2) Address tables and indexes imported first.
 
+  CheckBool ImportLabels(const LabelManager& abs32_label_manager,
+                         const LabelManager& rel32_label_manager)
+      WARN_UNUSED_RESULT;
 
   // (3) Add instructions in the order needed to generate bytes of file.
   // NOTE: If any of these methods ever fail, the EncodedProgram instance
   // has failed and should be discarded.
   CheckBool AddOrigin(RVA rva) WARN_UNUSED_RESULT;
   CheckBool AddCopy(size_t count, const void* bytes) WARN_UNUSED_RESULT;
   CheckBool AddRel32(int label_index) WARN_UNUSED_RESULT;
   CheckBool AddRel32ARM(uint16_t op, int label_index) WARN_UNUSED_RESULT;
   CheckBool AddAbs32(int label_index) WARN_UNUSED_RESULT;
   CheckBool AddAbs64(int label_index) WARN_UNUSED_RESULT;
@@ skipping 40 matching lines @@
     LAST_ARM    = 0x5FFF,
   };
 
   typedef NoThrowBuffer<RVA> RvaVector;
   typedef NoThrowBuffer<size_t> SizeTVector;
   typedef NoThrowBuffer<uint32_t> UInt32Vector;
   typedef NoThrowBuffer<uint8_t> UInt8Vector;
   typedef NoThrowBuffer<OP> OPVector;
 
   void DebuggingSummary();
+
+  // Helper for ImportLabels().
+  static CheckBool WriteRvasToList(const LabelManager& label_manager,
+                                   RvaVector* rvas);
+
+  // Helper for ImportLabels().
+  static void FillUnassignedRvaSlots(RvaVector* rvas);
+
   CheckBool GeneratePeRelocations(SinkStream* buffer,
                                   uint8_t type) WARN_UNUSED_RESULT;
   CheckBool GenerateElfRelocations(Elf32_Word pending_elf_relocation_table,
                                    SinkStream *buffer) WARN_UNUSED_RESULT;
 
   // Decodes and evaluates courgette ops for ARM rel32 addresses.
   CheckBool EvaluateRel32ARM(OP op, size_t& ix_rel32_ix, RVA& current_rva,
                              SinkStream* output);
 
   // Binary assembly language tables.
@@ skipping 15 matching lines @@
 };
 
 // Deserializes program from a stream set to |*output|. Returns C_OK if
 // successful, otherwise assigns |*output| to null and returns an error status.
 Status ReadEncodedProgram(SourceStreamSet* source,
                           std::unique_ptr<EncodedProgram>* output);
 
 }  // namespace courgette
 
 #endif  // COURGETTE_ENCODED_PROGRAM_H_