//===- IR.cpp - C Interface for Core MLIR APIs ----------------------------===//
//
// 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-c/IR.h"
#include "mlir-c/Support.h"

#include "mlir/AsmParser/AsmParser.h"
#include "mlir/Bytecode/BytecodeWriter.h"
#include "mlir/CAPI/IR.h"
#include "mlir/CAPI/Support.h"
#include "mlir/CAPI/Utils.h"
#include "mlir/IR/Attributes.h"
#include "mlir/IR/BuiltinAttributes.h"
#include "mlir/IR/BuiltinOps.h"
#include "mlir/IR/Diagnostics.h"
#include "mlir/IR/Dialect.h"
#include "mlir/IR/Location.h"
#include "mlir/IR/Operation.h"
#include "mlir/IR/OperationSupport.h"
#include "mlir/IR/Types.h"
#include "mlir/IR/Value.h"
#include "mlir/IR/Verifier.h"
#include "mlir/IR/Visitors.h"
#include "mlir/Interfaces/InferTypeOpInterface.h"
#include "mlir/Parser/Parser.h"
#include "llvm/Support/ThreadPool.h"

#include <cstddef>
#include <memory>
#include <optional>

using namespace mlir;

//===----------------------------------------------------------------------===//
// Context API.
//===----------------------------------------------------------------------===//

MlirContext mlirContextCreate() {
  auto *context = new MLIRContext;
  return wrap(context);
}

static inline MLIRContext::Threading toThreadingEnum(bool threadingEnabled) {
  return threadingEnabled ? MLIRContext::Threading::ENABLED
                          : MLIRContext::Threading::DISABLED;
}

MlirContext mlirContextCreateWithThreading(bool threadingEnabled) {
  auto *context = new MLIRContext(toThreadingEnum(threadingEnabled));
  return wrap(context);
}

MlirContext mlirContextCreateWithRegistry(MlirDialectRegistry registry,
                                          bool threadingEnabled) {
  auto *context =
      new MLIRContext(*unwrap(registry), toThreadingEnum(threadingEnabled));
  return wrap(context);
}

bool mlirContextEqual(MlirContext ctx1, MlirContext ctx2) {
  return unwrap(ctx1) == unwrap(ctx2);
}

void mlirContextDestroy(MlirContext context) { delete unwrap(context); }

void mlirContextSetAllowUnregisteredDialects(MlirContext context, bool allow) {
  unwrap(context)->allowUnregisteredDialects(allow);
}

bool mlirContextGetAllowUnregisteredDialects(MlirContext context) {
  return unwrap(context)->allowsUnregisteredDialects();
}
intptr_t mlirContextGetNumRegisteredDialects(MlirContext context) {
  return static_cast<intptr_t>(unwrap(context)->getAvailableDialects().size());
}

void mlirContextAppendDialectRegistry(MlirContext ctx,
                                      MlirDialectRegistry registry) {
  unwrap(ctx)->appendDialectRegistry(*unwrap(registry));
}

// TODO: expose a cheaper way than constructing + sorting a vector only to take
// its size.
intptr_t mlirContextGetNumLoadedDialects(MlirContext context) {
  return static_cast<intptr_t>(unwrap(context)->getLoadedDialects().size());
}

MlirDialect mlirContextGetOrLoadDialect(MlirContext context,
                                        MlirStringRef name) {
  return wrap(unwrap(context)->getOrLoadDialect(unwrap(name)));
}

bool mlirContextIsRegisteredOperation(MlirContext context, MlirStringRef name) {
  return unwrap(context)->isOperationRegistered(unwrap(name));
}

void mlirContextEnableMultithreading(MlirContext context, bool enable) {
  return unwrap(context)->enableMultithreading(enable);
}

void mlirContextLoadAllAvailableDialects(MlirContext context) {
  unwrap(context)->loadAllAvailableDialects();
}

void mlirContextSetThreadPool(MlirContext context,
                              MlirLlvmThreadPool threadPool) {
  unwrap(context)->setThreadPool(*unwrap(threadPool));
}

//===----------------------------------------------------------------------===//
// Dialect API.
//===----------------------------------------------------------------------===//

MlirContext mlirDialectGetContext(MlirDialect dialect) {
  return wrap(unwrap(dialect)->getContext());
}

bool mlirDialectEqual(MlirDialect dialect1, MlirDialect dialect2) {
  return unwrap(dialect1) == unwrap(dialect2);
}

MlirStringRef mlirDialectGetNamespace(MlirDialect dialect) {
  return wrap(unwrap(dialect)->getNamespace());
}

//===----------------------------------------------------------------------===//
// DialectRegistry API.
//===----------------------------------------------------------------------===//

MlirDialectRegistry mlirDialectRegistryCreate() {
  return wrap(new DialectRegistry());
}

void mlirDialectRegistryDestroy(MlirDialectRegistry registry) {
  delete unwrap(registry);
}

//===----------------------------------------------------------------------===//
// AsmState API.
//===----------------------------------------------------------------------===//

MlirAsmState mlirAsmStateCreateForOperation(MlirOperation op,
                                            MlirOpPrintingFlags flags) {
  return wrap(new AsmState(unwrap(op), *unwrap(flags)));
}

static Operation *findParent(Operation *op, bool shouldUseLocalScope) {
  do {
    // If we are printing local scope, stop at the first operation that is
    // isolated from above.
    if (shouldUseLocalScope && op->hasTrait<OpTrait::IsIsolatedFromAbove>())
      break;

    // Otherwise, traverse up to the next parent.
    Operation *parentOp = op->getParentOp();
    if (!parentOp)
      break;
    op = parentOp;
  } while (true);
  return op;
}

MlirAsmState mlirAsmStateCreateForValue(MlirValue value,
                                        MlirOpPrintingFlags flags) {
  Operation *op;
  mlir::Value val = unwrap(value);
  if (auto result = llvm::dyn_cast<OpResult>(val)) {
    op = result.getOwner();
  } else {
    op = llvm::cast<BlockArgument>(val).getOwner()->getParentOp();
    if (!op) {
      emitError(val.getLoc()) << "<<UNKNOWN SSA VALUE>>";
      return {nullptr};
    }
  }
  op = findParent(op, unwrap(flags)->shouldUseLocalScope());
  return wrap(new AsmState(op, *unwrap(flags)));
}

/// Destroys printing flags created with mlirAsmStateCreate.
void mlirAsmStateDestroy(MlirAsmState state) { delete unwrap(state); }

//===----------------------------------------------------------------------===//
// Printing flags API.
//===----------------------------------------------------------------------===//

MlirOpPrintingFlags mlirOpPrintingFlagsCreate() {
  return wrap(new OpPrintingFlags());
}

void mlirOpPrintingFlagsDestroy(MlirOpPrintingFlags flags) {
  delete unwrap(flags);
}

void mlirOpPrintingFlagsElideLargeElementsAttrs(MlirOpPrintingFlags flags,
                                                intptr_t largeElementLimit) {
  unwrap(flags)->elideLargeElementsAttrs(largeElementLimit);
}

void mlirOpPrintingFlagsElideLargeResourceString(MlirOpPrintingFlags flags,
                                                 intptr_t largeResourceLimit) {
  unwrap(flags)->elideLargeResourceString(largeResourceLimit);
}

void mlirOpPrintingFlagsEnableDebugInfo(MlirOpPrintingFlags flags, bool enable,
                                        bool prettyForm) {
  unwrap(flags)->enableDebugInfo(enable, /*prettyForm=*/prettyForm);
}

void mlirOpPrintingFlagsPrintGenericOpForm(MlirOpPrintingFlags flags) {
  unwrap(flags)->printGenericOpForm();
}

void mlirOpPrintingFlagsUseLocalScope(MlirOpPrintingFlags flags) {
  unwrap(flags)->useLocalScope();
}

void mlirOpPrintingFlagsAssumeVerified(MlirOpPrintingFlags flags) {
  unwrap(flags)->assumeVerified();
}

void mlirOpPrintingFlagsSkipRegions(MlirOpPrintingFlags flags) {
  unwrap(flags)->skipRegions();
}
//===----------------------------------------------------------------------===//
// Bytecode printing flags API.
//===----------------------------------------------------------------------===//

MlirBytecodeWriterConfig mlirBytecodeWriterConfigCreate() {
  return wrap(new BytecodeWriterConfig());
}

void mlirBytecodeWriterConfigDestroy(MlirBytecodeWriterConfig config) {
  delete unwrap(config);
}

void mlirBytecodeWriterConfigDesiredEmitVersion(MlirBytecodeWriterConfig flags,
                                                int64_t version) {
  unwrap(flags)->setDesiredBytecodeVersion(version);
}

//===----------------------------------------------------------------------===//
// Location API.
//===----------------------------------------------------------------------===//

MlirAttribute mlirLocationGetAttribute(MlirLocation location) {
  return wrap(LocationAttr(unwrap(location)));
}

MlirLocation mlirLocationFromAttribute(MlirAttribute attribute) {
  return wrap(Location(llvm::cast<LocationAttr>(unwrap(attribute))));
}

MlirLocation mlirLocationFileLineColGet(MlirContext context,
                                        MlirStringRef filename, unsigned line,
                                        unsigned col) {
  return wrap(Location(
      FileLineColLoc::get(unwrap(context), unwrap(filename), line, col)));
}

MlirLocation mlirLocationCallSiteGet(MlirLocation callee, MlirLocation caller) {
  return wrap(Location(CallSiteLoc::get(unwrap(callee), unwrap(caller))));
}

MlirLocation mlirLocationFusedGet(MlirContext ctx, intptr_t nLocations,
                                  MlirLocation const *locations,
                                  MlirAttribute metadata) {
  SmallVector<Location, 4> locs;
  ArrayRef<Location> unwrappedLocs = unwrapList(nLocations, locations, locs);
  return wrap(FusedLoc::get(unwrappedLocs, unwrap(metadata), unwrap(ctx)));
}

MlirLocation mlirLocationNameGet(MlirContext context, MlirStringRef name,
                                 MlirLocation childLoc) {
  if (mlirLocationIsNull(childLoc))
    return wrap(
        Location(NameLoc::get(StringAttr::get(unwrap(context), unwrap(name)))));
  return wrap(Location(NameLoc::get(
      StringAttr::get(unwrap(context), unwrap(name)), unwrap(childLoc))));
}

MlirLocation mlirLocationUnknownGet(MlirContext context) {
  return wrap(Location(UnknownLoc::get(unwrap(context))));
}

bool mlirLocationEqual(MlirLocation l1, MlirLocation l2) {
  return unwrap(l1) == unwrap(l2);
}

MlirContext mlirLocationGetContext(MlirLocation location) {
  return wrap(unwrap(location).getContext());
}

void mlirLocationPrint(MlirLocation location, MlirStringCallback callback,
                       void *userData) {
  detail::CallbackOstream stream(callback, userData);
  unwrap(location).print(stream);
}

//===----------------------------------------------------------------------===//
// Module API.
//===----------------------------------------------------------------------===//

MlirModule mlirModuleCreateEmpty(MlirLocation location) {
  return wrap(ModuleOp::create(unwrap(location)));
}

MlirModule mlirModuleCreateParse(MlirContext context, MlirStringRef module) {
  OwningOpRef<ModuleOp> owning =
      parseSourceString<ModuleOp>(unwrap(module), unwrap(context));
  if (!owning)
    return MlirModule{nullptr};
  return MlirModule{owning.release().getOperation()};
}

MlirContext mlirModuleGetContext(MlirModule module) {
  return wrap(unwrap(module).getContext());
}

MlirBlock mlirModuleGetBody(MlirModule module) {
  return wrap(unwrap(module).getBody());
}

void mlirModuleDestroy(MlirModule module) {
  // Transfer ownership to an OwningOpRef<ModuleOp> so that its destructor is
  // called.
  OwningOpRef<ModuleOp>(unwrap(module));
}

MlirOperation mlirModuleGetOperation(MlirModule module) {
  return wrap(unwrap(module).getOperation());
}

MlirModule mlirModuleFromOperation(MlirOperation op) {
  return wrap(dyn_cast<ModuleOp>(unwrap(op)));
}

//===----------------------------------------------------------------------===//
// Operation state API.
//===----------------------------------------------------------------------===//

MlirOperationState mlirOperationStateGet(MlirStringRef name, MlirLocation loc) {
  MlirOperationState state;
  state.name = name;
  state.location = loc;
  state.nResults = 0;
  state.results = nullptr;
  state.nOperands = 0;
  state.operands = nullptr;
  state.nRegions = 0;
  state.regions = nullptr;
  state.nSuccessors = 0;
  state.successors = nullptr;
  state.nAttributes = 0;
  state.attributes = nullptr;
  state.enableResultTypeInference = false;
  return state;
}

#define APPEND_ELEMS(type, sizeName, elemName)                                 \
  state->elemName =                                                            \
      (type *)realloc(state->elemName, (state->sizeName + n) * sizeof(type));  \
  memcpy(state->elemName + state->sizeName, elemName, n * sizeof(type));       \
  state->sizeName += n;

void mlirOperationStateAddResults(MlirOperationState *state, intptr_t n,
                                  MlirType const *results) {
  APPEND_ELEMS(MlirType, nResults, results);
}

void mlirOperationStateAddOperands(MlirOperationState *state, intptr_t n,
                                   MlirValue const *operands) {
  APPEND_ELEMS(MlirValue, nOperands, operands);
}
void mlirOperationStateAddOwnedRegions(MlirOperationState *state, intptr_t n,
                                       MlirRegion const *regions) {
  APPEND_ELEMS(MlirRegion, nRegions, regions);
}
void mlirOperationStateAddSuccessors(MlirOperationState *state, intptr_t n,
                                     MlirBlock const *successors) {
  APPEND_ELEMS(MlirBlock, nSuccessors, successors);
}
void mlirOperationStateAddAttributes(MlirOperationState *state, intptr_t n,
                                     MlirNamedAttribute const *attributes) {
  APPEND_ELEMS(MlirNamedAttribute, nAttributes, attributes);
}

void mlirOperationStateEnableResultTypeInference(MlirOperationState *state) {
  state->enableResultTypeInference = true;
}

//===----------------------------------------------------------------------===//
// Operation API.
//===----------------------------------------------------------------------===//

static LogicalResult inferOperationTypes(OperationState &state) {
  MLIRContext *context = state.getContext();
  std::optional<RegisteredOperationName> info = state.name.getRegisteredInfo();
  if (!info) {
    emitError(state.location)
        << "type inference was requested for the operation " << state.name
        << ", but the operation was not registered; ensure that the dialect "
           "containing the operation is linked into MLIR and registered with "
           "the context";
    return failure();
  }

  auto *inferInterface = info->getInterface<InferTypeOpInterface>();
  if (!inferInterface) {
    emitError(state.location)
        << "type inference was requested for the operation " << state.name
        << ", but the operation does not support type inference; result "
           "types must be specified explicitly";
    return failure();
  }

  DictionaryAttr attributes = state.attributes.getDictionary(context);
  OpaqueProperties properties = state.getRawProperties();

  if (!properties && info->getOpPropertyByteSize() > 0 && !attributes.empty()) {
    auto prop = std::make_unique<char[]>(info->getOpPropertyByteSize());
    properties = OpaqueProperties(prop.get());
    if (properties) {
      auto emitError = [&]() {
        return mlir::emitError(state.location)
               << " failed properties conversion while building "
               << state.name.getStringRef() << " with `" << attributes << "`: ";
      };
      if (failed(info->setOpPropertiesFromAttribute(state.name, properties,
                                                    attributes, emitError)))
        return failure();
    }
    if (succeeded(inferInterface->inferReturnTypes(
            context, state.location, state.operands, attributes, properties,
            state.regions, state.types))) {
      return success();
    }
    // Diagnostic emitted by interface.
    return failure();
  }

  if (succeeded(inferInterface->inferReturnTypes(
          context, state.location, state.operands, attributes, properties,
          state.regions, state.types)))
    return success();

  // Diagnostic emitted by interface.
  return failure();
}

MlirOperation mlirOperationCreate(MlirOperationState *state) {
  assert(state);
  OperationState cppState(unwrap(state->location), unwrap(state->name));
  SmallVector<Type, 4> resultStorage;
  SmallVector<Value, 8> operandStorage;
  SmallVector<Block *, 2> successorStorage;
  cppState.addTypes(unwrapList(state->nResults, state->results, resultStorage));
  cppState.addOperands(
      unwrapList(state->nOperands, state->operands, operandStorage));
  cppState.addSuccessors(
      unwrapList(state->nSuccessors, state->successors, successorStorage));

  cppState.attributes.reserve(state->nAttributes);
  for (intptr_t i = 0; i < state->nAttributes; ++i)
    cppState.addAttribute(unwrap(state->attributes[i].name),
                          unwrap(state->attributes[i].attribute));

  for (intptr_t i = 0; i < state->nRegions; ++i)
    cppState.addRegion(std::unique_ptr<Region>(unwrap(state->regions[i])));

  free(state->results);
  free(state->operands);
  free(state->successors);
  free(state->regions);
  free(state->attributes);

  // Infer result types.
  if (state->enableResultTypeInference) {
    assert(cppState.types.empty() &&
           "result type inference enabled and result types provided");
    if (failed(inferOperationTypes(cppState)))
      return {nullptr};
  }

  return wrap(Operation::create(cppState));
}

MlirOperation mlirOperationCreateParse(MlirContext context,
                                       MlirStringRef sourceStr,
                                       MlirStringRef sourceName) {

  return wrap(
      parseSourceString(unwrap(sourceStr), unwrap(context), unwrap(sourceName))
          .release());
}

MlirOperation mlirOperationClone(MlirOperation op) {
  return wrap(unwrap(op)->clone());
}

void mlirOperationDestroy(MlirOperation op) { unwrap(op)->erase(); }

void mlirOperationRemoveFromParent(MlirOperation op) { unwrap(op)->remove(); }

bool mlirOperationEqual(MlirOperation op, MlirOperation other) {
  return unwrap(op) == unwrap(other);
}

MlirContext mlirOperationGetContext(MlirOperation op) {
  return wrap(unwrap(op)->getContext());
}

MlirLocation mlirOperationGetLocation(MlirOperation op) {
  return wrap(unwrap(op)->getLoc());
}

MlirTypeID mlirOperationGetTypeID(MlirOperation op) {
  if (auto info = unwrap(op)->getRegisteredInfo())
    return wrap(info->getTypeID());
  return {nullptr};
}

MlirIdentifier mlirOperationGetName(MlirOperation op) {
  return wrap(unwrap(op)->getName().getIdentifier());
}

MlirBlock mlirOperationGetBlock(MlirOperation op) {
  return wrap(unwrap(op)->getBlock());
}

MlirOperation mlirOperationGetParentOperation(MlirOperation op) {
  return wrap(unwrap(op)->getParentOp());
}

intptr_t mlirOperationGetNumRegions(MlirOperation op) {
  return static_cast<intptr_t>(unwrap(op)->getNumRegions());
}

MlirRegion mlirOperationGetRegion(MlirOperation op, intptr_t pos) {
  return wrap(&unwrap(op)->getRegion(static_cast<unsigned>(pos)));
}

MlirRegion mlirOperationGetFirstRegion(MlirOperation op) {
  Operation *cppOp = unwrap(op);
  if (cppOp->getNumRegions() == 0)
    return wrap(static_cast<Region *>(nullptr));
  return wrap(&cppOp->getRegion(0));
}

MlirRegion mlirRegionGetNextInOperation(MlirRegion region) {
  Region *cppRegion = unwrap(region);
  Operation *parent = cppRegion->getParentOp();
  intptr_t next = cppRegion->getRegionNumber() + 1;
  if (parent->getNumRegions() > next)
    return wrap(&parent->getRegion(next));
  return wrap(static_cast<Region *>(nullptr));
}

MlirOperation mlirOperationGetNextInBlock(MlirOperation op) {
  return wrap(unwrap(op)->getNextNode());
}

intptr_t mlirOperationGetNumOperands(MlirOperation op) {
  return static_cast<intptr_t>(unwrap(op)->getNumOperands());
}

MlirValue mlirOperationGetOperand(MlirOperation op, intptr_t pos) {
  return wrap(unwrap(op)->getOperand(static_cast<unsigned>(pos)));
}

void mlirOperationSetOperand(MlirOperation op, intptr_t pos,
                             MlirValue newValue) {
  unwrap(op)->setOperand(static_cast<unsigned>(pos), unwrap(newValue));
}

void mlirOperationSetOperands(MlirOperation op, intptr_t nOperands,
                              MlirValue const *operands) {
  SmallVector<Value> ops;
  unwrap(op)->setOperands(unwrapList(nOperands, operands, ops));
}

intptr_t mlirOperationGetNumResults(MlirOperation op) {
  return static_cast<intptr_t>(unwrap(op)->getNumResults());
}

MlirValue mlirOperationGetResult(MlirOperation op, intptr_t pos) {
  return wrap(unwrap(op)->getResult(static_cast<unsigned>(pos)));
}

intptr_t mlirOperationGetNumSuccessors(MlirOperation op) {
  return static_cast<intptr_t>(unwrap(op)->getNumSuccessors());
}

MlirBlock mlirOperationGetSuccessor(MlirOperation op, intptr_t pos) {
  return wrap(unwrap(op)->getSuccessor(static_cast<unsigned>(pos)));
}

MLIR_CAPI_EXPORTED bool
mlirOperationHasInherentAttributeByName(MlirOperation op, MlirStringRef name) {
  std::optional<Attribute> attr = unwrap(op)->getInherentAttr(unwrap(name));
  return attr.has_value();
}

MlirAttribute mlirOperationGetInherentAttributeByName(MlirOperation op,
                                                      MlirStringRef name) {
  std::optional<Attribute> attr = unwrap(op)->getInherentAttr(unwrap(name));
  if (attr.has_value())
    return wrap(*attr);
  return {};
}

void mlirOperationSetInherentAttributeByName(MlirOperation op,
                                             MlirStringRef name,
                                             MlirAttribute attr) {
  unwrap(op)->setInherentAttr(
      StringAttr::get(unwrap(op)->getContext(), unwrap(name)), unwrap(attr));
}

intptr_t mlirOperationGetNumDiscardableAttributes(MlirOperation op) {
  return static_cast<intptr_t>(
      llvm::range_size(unwrap(op)->getDiscardableAttrs()));
}

MlirNamedAttribute mlirOperationGetDiscardableAttribute(MlirOperation op,
                                                        intptr_t pos) {
  NamedAttribute attr =
      *std::next(unwrap(op)->getDiscardableAttrs().begin(), pos);
  return MlirNamedAttribute{wrap(attr.getName()), wrap(attr.getValue())};
}

MlirAttribute mlirOperationGetDiscardableAttributeByName(MlirOperation op,
                                                         MlirStringRef name) {
  return wrap(unwrap(op)->getDiscardableAttr(unwrap(name)));
}

void mlirOperationSetDiscardableAttributeByName(MlirOperation op,
                                                MlirStringRef name,
                                                MlirAttribute attr) {
  unwrap(op)->setDiscardableAttr(unwrap(name), unwrap(attr));
}

bool mlirOperationRemoveDiscardableAttributeByName(MlirOperation op,
                                                   MlirStringRef name) {
  return !!unwrap(op)->removeDiscardableAttr(unwrap(name));
}

void mlirOperationSetSuccessor(MlirOperation op, intptr_t pos,
                               MlirBlock block) {
  unwrap(op)->setSuccessor(unwrap(block), static_cast<unsigned>(pos));
}

intptr_t mlirOperationGetNumAttributes(MlirOperation op) {
  return static_cast<intptr_t>(unwrap(op)->getAttrs().size());
}

MlirNamedAttribute mlirOperationGetAttribute(MlirOperation op, intptr_t pos) {
  NamedAttribute attr = unwrap(op)->getAttrs()[pos];
  return MlirNamedAttribute{wrap(attr.getName()), wrap(attr.getValue())};
}

MlirAttribute mlirOperationGetAttributeByName(MlirOperation op,
                                              MlirStringRef name) {
  return wrap(unwrap(op)->getAttr(unwrap(name)));
}

void mlirOperationSetAttributeByName(MlirOperation op, MlirStringRef name,
                                     MlirAttribute attr) {
  unwrap(op)->setAttr(unwrap(name), unwrap(attr));
}

bool mlirOperationRemoveAttributeByName(MlirOperation op, MlirStringRef name) {
  return !!unwrap(op)->removeAttr(unwrap(name));
}

void mlirOperationPrint(MlirOperation op, MlirStringCallback callback,
                        void *userData) {
  detail::CallbackOstream stream(callback, userData);
  unwrap(op)->print(stream);
}

void mlirOperationPrintWithFlags(MlirOperation op, MlirOpPrintingFlags flags,
                                 MlirStringCallback callback, void *userData) {
  detail::CallbackOstream stream(callback, userData);
  unwrap(op)->print(stream, *unwrap(flags));
}

void mlirOperationPrintWithState(MlirOperation op, MlirAsmState state,
                                 MlirStringCallback callback, void *userData) {
  detail::CallbackOstream stream(callback, userData);
  if (state.ptr)
    unwrap(op)->print(stream, *unwrap(state));
  unwrap(op)->print(stream);
}

void mlirOperationWriteBytecode(MlirOperation op, MlirStringCallback callback,
                                void *userData) {
  detail::CallbackOstream stream(callback, userData);
  // As no desired version is set, no failure can occur.
  (void)writeBytecodeToFile(unwrap(op), stream);
}

MlirLogicalResult mlirOperationWriteBytecodeWithConfig(
    MlirOperation op, MlirBytecodeWriterConfig config,
    MlirStringCallback callback, void *userData) {
  detail::CallbackOstream stream(callback, userData);
  return wrap(writeBytecodeToFile(unwrap(op), stream, *unwrap(config)));
}

void mlirOperationDump(MlirOperation op) { return unwrap(op)->dump(); }

bool mlirOperationVerify(MlirOperation op) {
  return succeeded(verify(unwrap(op)));
}

void mlirOperationMoveAfter(MlirOperation op, MlirOperation other) {
  return unwrap(op)->moveAfter(unwrap(other));
}

void mlirOperationMoveBefore(MlirOperation op, MlirOperation other) {
  return unwrap(op)->moveBefore(unwrap(other));
}

static mlir::WalkResult unwrap(MlirWalkResult result) {
  switch (result) {
  case MlirWalkResultAdvance:
    return mlir::WalkResult::advance();

  case MlirWalkResultInterrupt:
    return mlir::WalkResult::interrupt();

  case MlirWalkResultSkip:
    return mlir::WalkResult::skip();
  }
  llvm_unreachable("unknown result in WalkResult::unwrap");
}

void mlirOperationWalk(MlirOperation op, MlirOperationWalkCallback callback,
                       void *userData, MlirWalkOrder walkOrder) {
  switch (walkOrder) {

  case MlirWalkPreOrder:
    unwrap(op)->walk<mlir::WalkOrder::PreOrder>(
        [callback, userData](Operation *op) {
          return unwrap(callback(wrap(op), userData));
        });
    break;
  case MlirWalkPostOrder:
    unwrap(op)->walk<mlir::WalkOrder::PostOrder>(
        [callback, userData](Operation *op) {
          return unwrap(callback(wrap(op), userData));
        });
  }
}

//===----------------------------------------------------------------------===//
// Region API.
//===----------------------------------------------------------------------===//

MlirRegion mlirRegionCreate() { return wrap(new Region); }

bool mlirRegionEqual(MlirRegion region, MlirRegion other) {
  return unwrap(region) == unwrap(other);
}

MlirBlock mlirRegionGetFirstBlock(MlirRegion region) {
  Region *cppRegion = unwrap(region);
  if (cppRegion->empty())
    return wrap(static_cast<Block *>(nullptr));
  return wrap(&cppRegion->front());
}

void mlirRegionAppendOwnedBlock(MlirRegion region, MlirBlock block) {
  unwrap(region)->push_back(unwrap(block));
}

void mlirRegionInsertOwnedBlock(MlirRegion region, intptr_t pos,
                                MlirBlock block) {
  auto &blockList = unwrap(region)->getBlocks();
  blockList.insert(std::next(blockList.begin(), pos), unwrap(block));
}

void mlirRegionInsertOwnedBlockAfter(MlirRegion region, MlirBlock reference,
                                     MlirBlock block) {
  Region *cppRegion = unwrap(region);
  if (mlirBlockIsNull(reference)) {
    cppRegion->getBlocks().insert(cppRegion->begin(), unwrap(block));
    return;
  }

  assert(unwrap(reference)->getParent() == unwrap(region) &&
         "expected reference block to belong to the region");
  cppRegion->getBlocks().insertAfter(Region::iterator(unwrap(reference)),
                                     unwrap(block));
}

void mlirRegionInsertOwnedBlockBefore(MlirRegion region, MlirBlock reference,
                                      MlirBlock block) {
  if (mlirBlockIsNull(reference))
    return mlirRegionAppendOwnedBlock(region, block);

  assert(unwrap(reference)->getParent() == unwrap(region) &&
         "expected reference block to belong to the region");
  unwrap(region)->getBlocks().insert(Region::iterator(unwrap(reference)),
                                     unwrap(block));
}

void mlirRegionDestroy(MlirRegion region) {
  delete static_cast<Region *>(region.ptr);
}

void mlirRegionTakeBody(MlirRegion target, MlirRegion source) {
  unwrap(target)->takeBody(*unwrap(source));
}

//===----------------------------------------------------------------------===//
// Block API.
//===----------------------------------------------------------------------===//

MlirBlock mlirBlockCreate(intptr_t nArgs, MlirType const *args,
                          MlirLocation const *locs) {
  Block *b = new Block;
  for (intptr_t i = 0; i < nArgs; ++i)
    b->addArgument(unwrap(args[i]), unwrap(locs[i]));
  return wrap(b);
}

bool mlirBlockEqual(MlirBlock block, MlirBlock other) {
  return unwrap(block) == unwrap(other);
}

MlirOperation mlirBlockGetParentOperation(MlirBlock block) {
  return wrap(unwrap(block)->getParentOp());
}

MlirRegion mlirBlockGetParentRegion(MlirBlock block) {
  return wrap(unwrap(block)->getParent());
}

MlirBlock mlirBlockGetNextInRegion(MlirBlock block) {
  return wrap(unwrap(block)->getNextNode());
}

MlirOperation mlirBlockGetFirstOperation(MlirBlock block) {
  Block *cppBlock = unwrap(block);
  if (cppBlock->empty())
    return wrap(static_cast<Operation *>(nullptr));
  return wrap(&cppBlock->front());
}

MlirOperation mlirBlockGetTerminator(MlirBlock block) {
  Block *cppBlock = unwrap(block);
  if (cppBlock->empty())
    return wrap(static_cast<Operation *>(nullptr));
  Operation &back = cppBlock->back();
  if (!back.hasTrait<OpTrait::IsTerminator>())
    return wrap(static_cast<Operation *>(nullptr));
  return wrap(&back);
}

void mlirBlockAppendOwnedOperation(MlirBlock block, MlirOperation operation) {
  unwrap(block)->push_back(unwrap(operation));
}

void mlirBlockInsertOwnedOperation(MlirBlock block, intptr_t pos,
                                   MlirOperation operation) {
  auto &opList = unwrap(block)->getOperations();
  opList.insert(std::next(opList.begin(), pos), unwrap(operation));
}

void mlirBlockInsertOwnedOperationAfter(MlirBlock block,
                                        MlirOperation reference,
                                        MlirOperation operation) {
  Block *cppBlock = unwrap(block);
  if (mlirOperationIsNull(reference)) {
    cppBlock->getOperations().insert(cppBlock->begin(), unwrap(operation));
    return;
  }

  assert(unwrap(reference)->getBlock() == unwrap(block) &&
         "expected reference operation to belong to the block");
  cppBlock->getOperations().insertAfter(Block::iterator(unwrap(reference)),
                                        unwrap(operation));
}

void mlirBlockInsertOwnedOperationBefore(MlirBlock block,
                                         MlirOperation reference,
                                         MlirOperation operation) {
  if (mlirOperationIsNull(reference))
    return mlirBlockAppendOwnedOperation(block, operation);

  assert(unwrap(reference)->getBlock() == unwrap(block) &&
         "expected reference operation to belong to the block");
  unwrap(block)->getOperations().insert(Block::iterator(unwrap(reference)),
                                        unwrap(operation));
}

void mlirBlockDestroy(MlirBlock block) { delete unwrap(block); }

void mlirBlockDetach(MlirBlock block) {
  Block *b = unwrap(block);
  b->getParent()->getBlocks().remove(b);
}

intptr_t mlirBlockGetNumArguments(MlirBlock block) {
  return static_cast<intptr_t>(unwrap(block)->getNumArguments());
}

MlirValue mlirBlockAddArgument(MlirBlock block, MlirType type,
                               MlirLocation loc) {
  return wrap(unwrap(block)->addArgument(unwrap(type), unwrap(loc)));
}

void mlirBlockEraseArgument(MlirBlock block, unsigned index) {
  return unwrap(block)->eraseArgument(index);
}

MlirValue mlirBlockInsertArgument(MlirBlock block, intptr_t pos, MlirType type,
                                  MlirLocation loc) {
  return wrap(unwrap(block)->insertArgument(pos, unwrap(type), unwrap(loc)));
}

MlirValue mlirBlockGetArgument(MlirBlock block, intptr_t pos) {
  return wrap(unwrap(block)->getArgument(static_cast<unsigned>(pos)));
}

void mlirBlockPrint(MlirBlock block, MlirStringCallback callback,
                    void *userData) {
  detail::CallbackOstream stream(callback, userData);
  unwrap(block)->print(stream);
}

//===----------------------------------------------------------------------===//
// Value API.
//===----------------------------------------------------------------------===//

bool mlirValueEqual(MlirValue value1, MlirValue value2) {
  return unwrap(value1) == unwrap(value2);
}

bool mlirValueIsABlockArgument(MlirValue value) {
  return llvm::isa<BlockArgument>(unwrap(value));
}

bool mlirValueIsAOpResult(MlirValue value) {
  return llvm::isa<OpResult>(unwrap(value));
}

MlirBlock mlirBlockArgumentGetOwner(MlirValue value) {
  return wrap(llvm::cast<BlockArgument>(unwrap(value)).getOwner());
}

intptr_t mlirBlockArgumentGetArgNumber(MlirValue value) {
  return static_cast<intptr_t>(
      llvm::cast<BlockArgument>(unwrap(value)).getArgNumber());
}

void mlirBlockArgumentSetType(MlirValue value, MlirType type) {
  llvm::cast<BlockArgument>(unwrap(value)).setType(unwrap(type));
}

MlirOperation mlirOpResultGetOwner(MlirValue value) {
  return wrap(llvm::cast<OpResult>(unwrap(value)).getOwner());
}

intptr_t mlirOpResultGetResultNumber(MlirValue value) {
  return static_cast<intptr_t>(
      llvm::cast<OpResult>(unwrap(value)).getResultNumber());
}

MlirType mlirValueGetType(MlirValue value) {
  return wrap(unwrap(value).getType());
}

void mlirValueSetType(MlirValue value, MlirType type) {
  unwrap(value).setType(unwrap(type));
}

void mlirValueDump(MlirValue value) { unwrap(value).dump(); }

void mlirValuePrint(MlirValue value, MlirStringCallback callback,
                    void *userData) {
  detail::CallbackOstream stream(callback, userData);
  unwrap(value).print(stream);
}

void mlirValuePrintAsOperand(MlirValue value, MlirAsmState state,
                             MlirStringCallback callback, void *userData) {
  detail::CallbackOstream stream(callback, userData);
  Value cppValue = unwrap(value);
  cppValue.printAsOperand(stream, *unwrap(state));
}

MlirOpOperand mlirValueGetFirstUse(MlirValue value) {
  Value cppValue = unwrap(value);
  if (cppValue.use_empty())
    return {};

  OpOperand *opOperand = cppValue.use_begin().getOperand();

  return wrap(opOperand);
}

void mlirValueReplaceAllUsesOfWith(MlirValue oldValue, MlirValue newValue) {
  unwrap(oldValue).replaceAllUsesWith(unwrap(newValue));
}

//===----------------------------------------------------------------------===//
// OpOperand API.
//===----------------------------------------------------------------------===//

bool mlirOpOperandIsNull(MlirOpOperand opOperand) { return !opOperand.ptr; }

MlirOperation mlirOpOperandGetOwner(MlirOpOperand opOperand) {
  return wrap(unwrap(opOperand)->getOwner());
}

MlirValue mlirOpOperandGetValue(MlirOpOperand opOperand) {
  return wrap(unwrap(opOperand)->get());
}

unsigned mlirOpOperandGetOperandNumber(MlirOpOperand opOperand) {
  return unwrap(opOperand)->getOperandNumber();
}

MlirOpOperand mlirOpOperandGetNextUse(MlirOpOperand opOperand) {
  if (mlirOpOperandIsNull(opOperand))
    return {};

  OpOperand *nextOpOperand = static_cast<OpOperand *>(
      unwrap(opOperand)->getNextOperandUsingThisValue());

  if (!nextOpOperand)
    return {};

  return wrap(nextOpOperand);
}

//===----------------------------------------------------------------------===//
// Type API.
//===----------------------------------------------------------------------===//

MlirType mlirTypeParseGet(MlirContext context, MlirStringRef type) {
  return wrap(mlir::parseType(unwrap(type), unwrap(context)));
}

MlirContext mlirTypeGetContext(MlirType type) {
  return wrap(unwrap(type).getContext());
}

MlirTypeID mlirTypeGetTypeID(MlirType type) {
  return wrap(unwrap(type).getTypeID());
}

MlirDialect mlirTypeGetDialect(MlirType type) {
  return wrap(&unwrap(type).getDialect());
}

bool mlirTypeEqual(MlirType t1, MlirType t2) {
  return unwrap(t1) == unwrap(t2);
}

void mlirTypePrint(MlirType type, MlirStringCallback callback, void *userData) {
  detail::CallbackOstream stream(callback, userData);
  unwrap(type).print(stream);
}

void mlirTypeDump(MlirType type) { unwrap(type).dump(); }

//===----------------------------------------------------------------------===//
// Attribute API.
//===----------------------------------------------------------------------===//

MlirAttribute mlirAttributeParseGet(MlirContext context, MlirStringRef attr) {
  return wrap(mlir::parseAttribute(unwrap(attr), unwrap(context)));
}

MlirContext mlirAttributeGetContext(MlirAttribute attribute) {
  return wrap(unwrap(attribute).getContext());
}

MlirType mlirAttributeGetType(MlirAttribute attribute) {
  Attribute attr = unwrap(attribute);
  if (auto typedAttr = llvm::dyn_cast<TypedAttr>(attr))
    return wrap(typedAttr.getType());
  return wrap(NoneType::get(attr.getContext()));
}

MlirTypeID mlirAttributeGetTypeID(MlirAttribute attr) {
  return wrap(unwrap(attr).getTypeID());
}

MlirDialect mlirAttributeGetDialect(MlirAttribute attr) {
  return wrap(&unwrap(attr).getDialect());
}

bool mlirAttributeEqual(MlirAttribute a1, MlirAttribute a2) {
  return unwrap(a1) == unwrap(a2);
}

void mlirAttributePrint(MlirAttribute attr, MlirStringCallback callback,
                        void *userData) {
  detail::CallbackOstream stream(callback, userData);
  unwrap(attr).print(stream);
}

void mlirAttributeDump(MlirAttribute attr) { unwrap(attr).dump(); }

MlirNamedAttribute mlirNamedAttributeGet(MlirIdentifier name,
                                         MlirAttribute attr) {
  return MlirNamedAttribute{name, attr};
}

//===----------------------------------------------------------------------===//
// Identifier API.
//===----------------------------------------------------------------------===//

MlirIdentifier mlirIdentifierGet(MlirContext context, MlirStringRef str) {
  return wrap(StringAttr::get(unwrap(context), unwrap(str)));
}

MlirContext mlirIdentifierGetContext(MlirIdentifier ident) {
  return wrap(unwrap(ident).getContext());
}

bool mlirIdentifierEqual(MlirIdentifier ident, MlirIdentifier other) {
  return unwrap(ident) == unwrap(other);
}

MlirStringRef mlirIdentifierStr(MlirIdentifier ident) {
  return wrap(unwrap(ident).strref());
}

//===----------------------------------------------------------------------===//
// Symbol and SymbolTable API.
//===----------------------------------------------------------------------===//

MlirStringRef mlirSymbolTableGetSymbolAttributeName() {
  return wrap(SymbolTable::getSymbolAttrName());
}

MlirStringRef mlirSymbolTableGetVisibilityAttributeName() {
  return wrap(SymbolTable::getVisibilityAttrName());
}

MlirSymbolTable mlirSymbolTableCreate(MlirOperation operation) {
  if (!unwrap(operation)->hasTrait<OpTrait::SymbolTable>())
    return wrap(static_cast<SymbolTable *>(nullptr));
  return wrap(new SymbolTable(unwrap(operation)));
}

void mlirSymbolTableDestroy(MlirSymbolTable symbolTable) {
  delete unwrap(symbolTable);
}

MlirOperation mlirSymbolTableLookup(MlirSymbolTable symbolTable,
                                    MlirStringRef name) {
  return wrap(unwrap(symbolTable)->lookup(StringRef(name.data, name.length)));
}

MlirAttribute mlirSymbolTableInsert(MlirSymbolTable symbolTable,
                                    MlirOperation operation) {
  return wrap((Attribute)unwrap(symbolTable)->insert(unwrap(operation)));
}

void mlirSymbolTableErase(MlirSymbolTable symbolTable,
                          MlirOperation operation) {
  unwrap(symbolTable)->erase(unwrap(operation));
}

MlirLogicalResult mlirSymbolTableReplaceAllSymbolUses(MlirStringRef oldSymbol,
                                                      MlirStringRef newSymbol,
                                                      MlirOperation from) {
  auto *cppFrom = unwrap(from);
  auto *context = cppFrom->getContext();
  auto oldSymbolAttr = StringAttr::get(context, unwrap(oldSymbol));
  auto newSymbolAttr = StringAttr::get(context, unwrap(newSymbol));
  return wrap(SymbolTable::replaceAllSymbolUses(oldSymbolAttr, newSymbolAttr,
                                                unwrap(from)));
}

void mlirSymbolTableWalkSymbolTables(MlirOperation from, bool allSymUsesVisible,
                                     void (*callback)(MlirOperation, bool,
                                                      void *userData),
                                     void *userData) {
  SymbolTable::walkSymbolTables(unwrap(from), allSymUsesVisible,
                                [&](Operation *foundOpCpp, bool isVisible) {
                                  callback(wrap(foundOpCpp), isVisible,
                                           userData);
                                });
}