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// Copyright 2018 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef DAWNNATIVE_ERROR_H_
#define DAWNNATIVE_ERROR_H_
#include "common/Result.h"
namespace dawn_native {
// This is the content of an error value for MaybeError or ResultOrError, split off to its own
// file to avoid having all files including headers like <string> and <vector>
class ErrorData;
enum class ErrorType : uint32_t { Validation, ContextLost, Unimplemented };
// MaybeError and ResultOrError are meant to be used as return value for function that are not
// expected to, but might fail. The handling of error is potentially much slower than successes.
using MaybeError = Result<void, ErrorData*>;
template <typename T>
using ResultOrError = Result<T, ErrorData*>;
// Returning a success is done like so:
// return {}; // for Error
// return SomethingOfTypeT; // for ResultOrError<T>
//
// Returning an error is done via:
// return DAWN_MAKE_ERROR(errorType, "My error message");
//
// but shorthand version for specific error types are preferred:
// return DAWN_VALIDATION_ERROR("My error message");
#define DAWN_MAKE_ERROR(TYPE, MESSAGE) MakeError(TYPE, MESSAGE, __FILE__, __func__, __LINE__)
#define DAWN_VALIDATION_ERROR(MESSAGE) DAWN_MAKE_ERROR(ErrorType::Validation, MESSAGE)
#define DAWN_CONTEXT_LOST_ERROR(MESSAGE) DAWN_MAKE_ERROR(ErrorType::ContextLost, MESSAGE)
#define DAWN_UNIMPLEMENTED_ERROR(MESSAGE) DAWN_MAKE_ERROR(ErrorType::Unimplemented, MESSAGE)
#define DAWN_CONCAT1(x, y) x##y
#define DAWN_CONCAT2(x, y) DAWN_CONCAT1(x, y)
#define DAWN_LOCAL_VAR DAWN_CONCAT2(_localVar, __LINE__)
// When Errors aren't handled explicitly, calls to functions returning errors should be
// wrapped in an DAWN_TRY. It will return the error if any, otherwise keep executing
// the current function.
#define DAWN_TRY(EXPR) \
{ \
auto DAWN_LOCAL_VAR = EXPR; \
if (DAWN_UNLIKELY(DAWN_LOCAL_VAR.IsError())) { \
ErrorData* error = DAWN_LOCAL_VAR.AcquireError(); \
AppendBacktrace(error, __FILE__, __func__, __LINE__); \
return {error}; \
} \
} \
for (;;) \
break
// DAWN_TRY_ASSIGN is the same as DAWN_TRY for ResultOrError and assigns the success value, if
// any, to VAR.
#define DAWN_TRY_ASSIGN(VAR, EXPR) \
{ \
auto DAWN_LOCAL_VAR = EXPR; \
if (DAWN_UNLIKELY(DAWN_LOCAL_VAR.IsError())) { \
ErrorData* error = DAWN_LOCAL_VAR.AcquireError(); \
AppendBacktrace(error, __FILE__, __func__, __LINE__); \
return {error}; \
} \
VAR = DAWN_LOCAL_VAR.AcquireSuccess(); \
} \
for (;;) \
break
// Implementation detail of DAWN_TRY and DAWN_TRY_ASSIGN's adding to the Error's backtrace.
void AppendBacktrace(ErrorData* error, const char* file, const char* function, int line);
// Implementation detail of DAWN_MAKE_ERROR
ErrorData* MakeError(ErrorType type,
const char* message,
const char* file,
const char* function,
int line);
} // namespace dawn_native
#endif // DAWNNATIVE_ERROR_H_