C++ (Cpp) CodeGenModule::getBlockDescriptorType Examples

Example #1

File: CGBlocks.cpp Project: YabinHu/mlang

static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info,
                    llvm::SmallVectorImpl<llvm::Type*> &elementTypes) {
  ASTContext &C = CGM.getContext();

  // The header is basically a 'struct { void *; int; int; void *; void *; }'.
  CharUnits ptrSize, ptrAlign, intSize, intAlign;
  llvm::tie(ptrSize, ptrAlign) = C.getTypeInfoInChars(C.UInt32Ty);
  llvm::tie(intSize, intAlign) = C.getTypeInfoInChars(C.Int32Ty);

  // Are there crazy embedded platforms where this isn't true?
  assert(intSize <= ptrSize && "layout assumptions horribly violated");

  CharUnits headerSize = ptrSize;
  if (2 * intSize < ptrAlign) headerSize += ptrSize;
  else headerSize += 2 * intSize;
  headerSize += 2 * ptrSize;

  info.BlockAlign = ptrAlign;
  info.BlockSize = headerSize;

  assert(elementTypes.empty());
  llvm::Type *i8p = CGM.getTypes().ConvertType(C.UInt32Ty);
  llvm::Type *intTy = CGM.getTypes().ConvertType(C.Int32Ty);
  elementTypes.push_back(i8p);
  elementTypes.push_back(intTy);
  elementTypes.push_back(intTy);
  elementTypes.push_back(i8p);
  elementTypes.push_back(CGM.getBlockDescriptorType());

  assert(elementTypes.size() == BlockHeaderSize);
}