//===- ControlFlowInterfaces.cpp - ControlFlow Interfaces -----------------===//
//
// 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/Interfaces/ControlFlowInterfaces.h"
#include "mlir/IR/StandardTypes.h"

using namespace mlir;

//===----------------------------------------------------------------------===//
// ControlFlowInterfaces
//===----------------------------------------------------------------------===//

#include "mlir/Interfaces/ControlFlowInterfaces.cpp.inc"

//===----------------------------------------------------------------------===//
// BranchOpInterface
//===----------------------------------------------------------------------===//

/// Returns the `BlockArgument` corresponding to operand `operandIndex` in some
/// successor if 'operandIndex' is within the range of 'operands', or None if
/// `operandIndex` isn't a successor operand index.
Optional<BlockArgument> mlir::detail::getBranchSuccessorArgument(
    Optional<OperandRange> operands, unsigned operandIndex, Block *successor) {
  // Check that the operands are valid.
  if (!operands || operands->empty())
    return llvm::None;

  // Check to ensure that this operand is within the range.
  unsigned operandsStart = operands->getBeginOperandIndex();
  if (operandIndex < operandsStart ||
      operandIndex >= (operandsStart + operands->size()))
    return llvm::None;

  // Index the successor.
  unsigned argIndex = operandIndex - operandsStart;
  return successor->getArgument(argIndex);
}

/// Verify that the given operands match those of the given successor block.
LogicalResult
mlir::detail::verifyBranchSuccessorOperands(Operation *op, unsigned succNo,
                                            Optional<OperandRange> operands) {
  if (!operands)
    return success();

  // Check the count.
  unsigned operandCount = operands->size();
  Block *destBB = op->getSuccessor(succNo);
  if (operandCount != destBB->getNumArguments())
    return op->emitError() << "branch has " << operandCount
                           << " operands for successor #" << succNo
                           << ", but target block has "
                           << destBB->getNumArguments();

  // Check the types.
  auto operandIt = operands->begin();
  for (unsigned i = 0; i != operandCount; ++i, ++operandIt) {
    if ((*operandIt).getType() != destBB->getArgument(i).getType())
      return op->emitError() << "type mismatch for bb argument #" << i
                             << " of successor #" << succNo;
  }
  return success();
}