path: root/lib/Target/CBackend/CBackend.cpp

//===-- Writer.cpp - Library for converting LLVM code to C ----------------===//
//
// This library implements the functionality defined in llvm/Assembly/CWriter.h
//
// TODO : Recursive types.
//
//===-----------------------------------------------------------------------==//

#include "llvm/Assembly/CWriter.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/iMemory.h"
#include "llvm/iTerminators.h"
#include "llvm/iPHINode.h"
#include "llvm/iOther.h"
#include "llvm/iOperators.h"
#include "llvm/SymbolTable.h"
#include "llvm/SlotCalculator.h"
#include "llvm/Support/InstVisitor.h"
#include "llvm/Support/InstIterator.h"
#include "Support/StringExtras.h"
#include "Support/STLExtras.h"
#include <algorithm>
#include <set>
using std::string;
using std::map;
using std::ostream;

namespace {
  class CWriter : public InstVisitor<CWriter> {
    ostream& Out; 
    SlotCalculator &Table;
    const Module *TheModule;
    map<const Type *, string> TypeNames;
    std::set<const Value*> MangledGlobals;
  public:
    inline CWriter(ostream &o, SlotCalculator &Tab, const Module *M)
      : Out(o), Table(Tab), TheModule(M) {
    }
    
    inline void write(Module *M) { printModule(M); }

    ostream &printType(const Type *Ty, const string &VariableName = "",
                       bool IgnoreName = false);

    void writeOperand(Value *Operand);
    void writeOperandInternal(Value *Operand);

    string getValueName(const Value *V);

  private :
    void printModule(Module *M);
    void printSymbolTable(const SymbolTable &ST);
    void printGlobal(const GlobalVariable *GV);
    void printFunctionSignature(const Function *F, bool Prototype);

    void printFunction(Function *);

    void printConstant(Constant *CPV);
    void printConstantArray(ConstantArray *CPA);

    // isInlinableInst - Attempt to inline instructions into their uses to build
    // trees as much as possible.  To do this, we have to consistently decide
    // what is acceptable to inline, so that variable declarations don't get
    // printed and an extra copy of the expr is not emitted.
    //
    static bool isInlinableInst(const Instruction &I) {
      // Must be an expression, must be used exactly once.  If it is dead, we
      // emit it inline where it would go.
      if (I.getType() == Type::VoidTy || I.use_size() != 1 ||
          isa<TerminatorInst>(I) || isa<CallInst>(I) || isa<PHINode>(I))
        return false;

      // Only inline instruction it it's use is in the same BB as the inst.
      return I.getParent() == cast<Instruction>(I.use_back())->getParent();
    }

    // Instruction visitation functions
    friend class InstVisitor<CWriter>;

    void visitReturnInst(ReturnInst &I);
    void visitBranchInst(BranchInst &I);

    void visitPHINode(PHINode &I) {}
    void visitBinaryOperator(Instruction &I);

    void visitCastInst (CastInst &I);
    void visitCallInst (CallInst &I);
    void visitShiftInst(ShiftInst &I) { visitBinaryOperator(I); }

    void visitMallocInst(MallocInst &I);
    void visitAllocaInst(AllocaInst &I);
    void visitFreeInst  (FreeInst   &I);
    void visitLoadInst  (LoadInst   &I);
    void visitStoreInst (StoreInst  &I);
    void visitGetElementPtrInst(GetElementPtrInst &I);

    void visitInstruction(Instruction &I) {
      std::cerr << "C Writer does not know about " << I;
      abort();
    }

    void outputLValue(Instruction *I) {
      Out << "  " << getValueName(I) << " = ";
    }
    void printBranchToBlock(BasicBlock *CurBlock, BasicBlock *SuccBlock,
                            unsigned Indent);
    void printIndexingExpression(Value *Ptr, User::op_iterator I,
                                 User::op_iterator E);
  };
}

// We dont want identifier names with ., space, -  in them. 
// So we replace them with _
static string makeNameProper(string x) {
  string tmp;
  for (string::iterator sI = x.begin(), sEnd = x.end(); sI != sEnd; sI++)
    switch (*sI) {
    case '.': tmp += "d_"; break;
    case ' ': tmp += "s_"; break;
    case '-': tmp += "D_"; break;
    default:  tmp += *sI;
    }

  return tmp;
}

string CWriter::getValueName(const Value *V) {
  if