path: root/lib/Bitcode/Writer/BitcodeWriter.cpp

//===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Bitcode writer implementation.
//
//===----------------------------------------------------------------------===//

#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/Bitcode/BitstreamWriter.h"
#include "llvm/Bitcode/LLVMBitCodes.h"
#include "ValueEnumerator.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Instructions.h"
#include "llvm/Module.h"
#include "llvm/ParameterAttributes.h"
#include "llvm/TypeSymbolTable.h"
#include "llvm/ValueSymbolTable.h"
#include "llvm/Support/MathExtras.h"
using namespace llvm;

static const unsigned CurVersion = 0;

static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  switch (Opcode) {
  default: assert(0 && "Unknown cast instruction!");
  case Instruction::Trunc   : return bitc::CAST_TRUNC;
  case Instruction::ZExt    : return bitc::CAST_ZEXT;
  case Instruction::SExt    : return bitc::CAST_SEXT;
  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  case Instruction::FPExt   : return bitc::CAST_FPEXT;
  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  case Instruction::BitCast : return bitc::CAST_BITCAST;
  }
}

static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  switch (Opcode) {
  default: assert(0 && "Unknown binary instruction!");
  case Instruction::Add:  return bitc::BINOP_ADD;
  case Instruction::Sub:  return bitc::BINOP_SUB;
  case Instruction::Mul:  return bitc::BINOP_MUL;
  case Instruction::UDiv: return bitc::BINOP_UDIV;
  case Instruction::FDiv:
  case Instruction::SDiv: return bitc::BINOP_SDIV;
  case Instruction::URem: return bitc::BINOP_UREM;
  case Instruction::FRem:
  case Instruction::SRem: return bitc::BINOP_SREM;
  case Instruction::Shl:  return bitc::BINOP_SHL;
  case Instruction::LShr: return bitc::BINOP_LSHR;
  case Instruction::AShr: return bitc::BINOP_ASHR;
  case Instruction::And:  return bitc::BINOP_AND;
  case Instruction::Or:   return bitc::BINOP_OR;
  case Instruction::Xor:  return bitc::BINOP_XOR;
  }
}



static void WriteStringRecord(unsigned Code, const std::string &Str, 
                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
  SmallVector<unsigned, 64> Vals;
  
  // Code: [strlen, strchar x N]
  Vals.push_back(Str.size());
  for (unsigned i = 0, e = Str.size(); i != e; ++i)
    Vals.push_back(Str[i]);
    
  // Emit the finished record.
  Stream.EmitRecord(Code, Vals, AbbrevToUse);
}

// Emit information about parameter attributes.
static void WriteParamAttrTable(const ValueEnumerator &VE, 
                                BitstreamWriter &Stream) {
  const std::vector<const ParamAttrsList*> &Attrs = VE.getParamAttrs();
  if (Attrs.empty()) return;
  
  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);

  SmallVector<uint64_t, 64> Record;
  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
    const ParamAttrsList *A = Attrs[i];
    for (unsigned op = 0, e = A->size(); op != e; ++op) {
      Record.push_back(A->getParamIndex(op));
      Record.push_back(A->getParamAttrsAtIndex(op));
    }
    
    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
    Record.clear();
  }
  
  Stream.ExitBlock();
}

/// WriteTypeTable - Write out the type table for a module.
static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
  
  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
  SmallVector<uint64_t, 64> TypeVals;
  
  // FIXME: Set up abbrevs now that we know the width of the type fields, etc.
  
  // Emit an entry count so the reader can reserve space.
  TypeVals.push_back(TypeList.