parse_number.h | Explore in Territory

// Copyright (c) 2016 Google Inc.
//
// 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 SOURCE_UTIL_PARSE_NUMBER_H_
#define SOURCE_UTIL_PARSE_NUMBER_H_

#include <functional>
#include <string>
#include <tuple>

#include "source/util/hex_float.h"
#include "spirv-tools/libspirv.h"

namespace spvtools {
namespace utils {

// A struct to hold the expected type information for the number in text to be
// parsed.
struct NumberType { … };

// Returns true if the type is a scalar integer type.
inline bool IsIntegral(const NumberType& type) { … }

// Returns true if the type is a scalar floating point type.
inline bool IsFloating(const NumberType& type) { … }

// Returns true if the type is a signed value.
inline bool IsSigned(const NumberType& type) { … }

// Returns true if the type is unknown.
inline bool IsUnknown(const NumberType& type) { … }

// Returns the number of bits in the type. This is only valid for integer and
// floating types.
inline int AssumedBitWidth(const NumberType& type) { … }

// A templated class with a static member function Clamp, where Clamp sets a
// referenced value of type T to 0 if T is an unsigned integer type, and
// returns true if it modified the referenced value.
template <typename T, typename = void>
class ClampToZeroIfUnsignedType { … };

// The specialization of ClampToZeroIfUnsignedType for unsigned integer types.
ClampToZeroIfUnsignedType<T, typename std::enable_if<std::is_unsigned<T>::value>::type>;

// Returns true if the given value fits within the target scalar integral type.
// The target type may have an unusual bit width. If the value was originally
// specified as a hexadecimal number, then the overflow bits should be zero.
// If it was hex and the target type is signed, then return the sign-extended
// value through the updated_value_for_hex pointer argument. On failure,
// returns false.
template <typename T>
bool CheckRangeAndIfHexThenSignExtend(T value, const NumberType& type,
                                      bool is_hex, T* updated_value_for_hex) { … }

// Parses a numeric value of a given type from the given text.  The number
// should take up the entire string, and should be within bounds for the target
// type. On success, returns true and populates the object referenced by
// value_pointer. On failure, returns false.
template <typename T>
bool ParseNumber(const char* text, T* value_pointer) { … }

// Enum to indicate the parsing and encoding status.
enum class EncodeNumberStatus { … };

// Parses an integer value of a given |type| from the given |text| and encodes
// the number by the given |emit| function. On success, returns
// EncodeNumberStatus::kSuccess and the parsed number will be consumed by the
// given |emit| function word by word (least significant word first). On
// failure, this function returns the error code of the encoding status and
// |emit| function will not be called. If the string pointer |error_msg| is not
// a nullptr, it will be overwritten with error messages in case of failure. In
// case of success, |error_msg| will not be touched. Integers up to 64 bits are
// supported.
EncodeNumberStatus ParseAndEncodeIntegerNumber(
    const char* text, const NumberType& type,
    std::function<void(uint32_t)> emit, std::string* error_msg);

// Parses a floating point value of a given |type| from the given |text| and
// encodes the number by the given |emit| function. On success, returns
// EncodeNumberStatus::kSuccess and the parsed number will be consumed by the
// given |emit| function word by word (least significant word first). On
// failure, this function returns the error code of the encoding status and
// |emit| function will not be called. If the string pointer |error_msg| is not
// a nullptr, it will be overwritten with error messages in case of failure. In
// case of success, |error_msg| will not be touched. Only 16, 32 and 64 bit
// floating point numbers are supported.
EncodeNumberStatus ParseAndEncodeFloatingPointNumber(
    const char* text, const NumberType& type,
    std::function<void(uint32_t)> emit, std::string* error_msg);

// Parses an integer or floating point number of a given |type| from the given
// |text| and encodes the number by the given |emit| function. On success,
// returns EncodeNumberStatus::kSuccess and the parsed number will be consumed
// by the given |emit| function word by word (least significant word first). On
// failure, this function returns the error code of the encoding status and
// |emit| function will not be called. If the string pointer |error_msg| is not
// a nullptr, it will be overwritten with error messages in case of failure. In
// case of success, |error_msg| will not be touched. Integers up to 64 bits
// and 16/32/64 bit floating point values are supported.
EncodeNumberStatus ParseAndEncodeNumber(const char* text,
                                        const NumberType& type,
                                        std::function<void(uint32_t)> emit,
                                        std::string* error_msg);

}  // namespace utils
}  // namespace spvtools

#endif  // SOURCE_UTIL_PARSE_NUMBER_H_
chromium/third_party/spirv-tools/src/source/util/parse_number.h
