text: //===- Builder.cpp - Builder definitions ----------------------------------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  
  #include "mlir/TableGen/Builder.h"
  #include "llvm/TableGen/Error.h"
  #include "llvm/TableGen/Record.h"
  
  using namespace mlir;
  using namespace mlir::tblgen;
  
  //===----------------------------------------------------------------------===//
  // Builder::Parameter
  //===----------------------------------------------------------------------===//
  
  /// Return a string containing the C++ type of this parameter.
  StringRef Builder::Parameter::getCppType() const {
    if (const auto *stringInit = dyn_cast<llvm::StringInit>(def))
      return stringInit->getValue();
    const llvm::Record *record = cast<llvm::DefInit>(def)->getDef();
    return record->getValueAsString("type");
  }
  
  /// Return an optional string containing the default value to use for this
  /// parameter.
  Optional<StringRef> Builder::Parameter::getDefaultValue() const {
    if (isa<llvm::StringInit>(def))
      return llvm::None;
    const llvm::Record *record = cast<llvm::DefInit>(def)->getDef();
    Optional<StringRef> value = record->getValueAsOptionalString("defaultValue");
    return value && !value->empty() ? value : llvm::None;
  }
  
  //===----------------------------------------------------------------------===//
  // Builder
  //===----------------------------------------------------------------------===//
  
  Builder::Builder(const llvm::Record *record, ArrayRef<SMLoc> loc)
      : def(record) {
    // Initialize the parameters of the builder.
    const llvm::DagInit *dag = def->getValueAsDag("dagParams");
    auto *defInit = dyn_cast<llvm::DefInit>(dag->getOperator());
    if (!defInit || !defInit->getDef()->getName().equals("ins"))
      PrintFatalError(def->getLoc(), "expected 'ins' in builders");
  
    bool seenDefaultValue = false;
    for (unsigned i = 0, e = dag->getNumArgs(); i < e; ++i) {
      const llvm::StringInit *paramName = dag->getArgName(i);
      const llvm::Init *paramValue = dag->getArg(i);
      Parameter param(paramName ? paramName->getValue() : Optional<StringRef>(),
                      paramValue);
  
      // Similarly to C++, once an argument with a default value is detected, the
      // following arguments must have default values as well.
      if (param.getDefaultValue()) {
        seenDefaultValue = true;
      } else if (seenDefaultValue) {
        PrintFatalError(loc,
                        "expected an argument with default value after other "
                        "arguments with default values");
      }
      parameters.emplace_back(param);
    }
  }
  
  /// Return an optional string containing the body of the builder.
  Optional<StringRef> Builder::getBody() const {
    Optional<StringRef> body = def->getValueAsOptionalString("body");
    return body && !body->empty() ? body : llvm::None;
  }
  