lib/VMCore/LLVMContext.cpp

   1 //===-- LLVMContext.cpp - Implement LLVMContext -----------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 //  This file implements LLVMContext, as a wrapper around the opaque
  11 //  class LLVMContextImpl.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/LLVMContext.h"
  16 #include "llvm/Constants.h"
  17 #include "llvm/Instruction.h"
  18 #include "llvm/Support/ManagedStatic.h"
  19 #include "LLVMContextImpl.h"
  20 #include <set>
  21
  22 using namespace llvm;
  23
  24 static ManagedStatic<LLVMContext> GlobalContext;
  25
  26 LLVMContext& llvm::getGlobalContext() {
  27   return *GlobalContext;
  28 }
  29
  30 LLVMContext::LLVMContext() : pImpl(new LLVMContextImpl(*this)) { }
  31 LLVMContext::~LLVMContext() { delete pImpl; }
  32
  33 GetElementPtrConstantExpr::GetElementPtrConstantExpr
  34   (Constant *C,
  35    const std::vector<Constant*> &IdxList,
  36    const Type *DestTy)
  37     : ConstantExpr(DestTy, Instruction::GetElementPtr,
  38                    OperandTraits<GetElementPtrConstantExpr>::op_end(this)
  39                    - (IdxList.size()+1),
  40                    IdxList.size()+1) {
  41   OperandList[0] = C;
  42   for (unsigned i = 0, E = IdxList.size(); i != E; ++i)
  43     OperandList[i+1] = IdxList[i];
  44 }
  45
  46 bool LLVMContext::RemoveDeadMetadata() {
  47   std::vector<const MDNode *> DeadMDNodes;
  48   bool Changed = false;
  49   while (1) {
  50
  51     for (LLVMContextImpl::MDNodeMapTy::MapTy::iterator
  52            I = pImpl->MDNodes.map_begin(),
  53            E = pImpl->MDNodes.map_end(); I != E; ++I) {
  54       const MDNode *N = cast<MDNode>(I->second);
  55       if (N->use_empty())
  56         DeadMDNodes.push_back(N);
  57     }
  58
  59     if (DeadMDNodes.empty())
  60       return Changed;
  61
  62     while (!DeadMDNodes.empty()) {
  63       const MDNode *N = DeadMDNodes.back(); DeadMDNodes.pop_back();
  64       delete N;
  65     }
  66   }
  67   return Changed;
  68 }