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8b264f8823
drgn was originally my side project, but for awhile now it's also been my work project. Update the copyright headers to reflect this, and add a copyright header to various files that were missing it.
98 lines
2.9 KiB
C
98 lines
2.9 KiB
C
// Copyright (c) Facebook, Inc. and its affiliates.
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// SPDX-License-Identifier: GPL-3.0+
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/**
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* @file
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*
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* Serialization and deserialization to and from memory.
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*
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* See @ref SerializationDeserialization.
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*/
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#ifndef DRGN_SERIALIZE_H
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#define DRGN_SERIALIZE_H
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#include <stdbool.h>
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#include <stdint.h>
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/**
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* @ingroup Internals
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*
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* @defgroup SerializationDeserialization Serialization/deserialization
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*
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* Serialization and deserialization of bits to and from memory.
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*
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* @{
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*/
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/** Copy the @p bit_size%th bit to the more-significant bits in an integer. */
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static inline int64_t sign_extend(int64_t svalue, uint64_t bit_size)
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{
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if (bit_size < 64) {
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int64_t mask;
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mask = INT64_C(1) << (bit_size - 1);
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svalue = (svalue ^ mask) - mask;
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}
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return svalue;
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}
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/** Truncate a signed integer to @p bit_size bits. */
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static inline int64_t truncate_signed(int64_t svalue, uint64_t bit_size)
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{
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if (bit_size < 64) {
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/* INT64_C(1) << 63 is undefined, so this must be UINT64_C. */
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svalue &= (UINT64_C(1) << bit_size) - 1;
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}
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return sign_extend(svalue, bit_size);
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}
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/** Truncate an unsigned integer to @p bit_size bits. */
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static inline uint64_t truncate_unsigned(uint64_t uvalue, uint64_t bit_size)
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{
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if (bit_size < 64)
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uvalue &= (UINT64_C(1) << bit_size) - 1;
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return uvalue;
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}
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/**
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* Serialize bits to a memory buffer.
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*
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* Note that this does not perform any bounds checking, so the caller must check
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* that <tt>bit_offset + bit_size</tt> is within the buffer.
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*
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* @param[in] buf Memory buffer to write to.
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* @param[in] bit_offset Offset in bits from the beginning of @p buf to where to
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* write. This is interpreted differently based on @p little_endian.
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* @param[in] uvalue Bits to write, in host order.
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* @param[in] bit_size Number of bits in @p uvalue. This must be grather than
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* zero and no more than 64. Note that this is not checked or truncated, so if
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* @p uvalue has more than this many bits, the results will likely be incorrect.
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* @param[in] little_endian Whether the bits should be written out in
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* little-endian order.
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*/
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void serialize_bits(void *buf, uint64_t bit_offset, uint64_t uvalue,
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uint8_t bit_size, bool little_endian);
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/**
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* Deserialize bits from a memory buffer.
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*
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* Note that this does not perform any bounds checking, so the caller must check
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* that <tt>bit_offset + bit_size</tt> is within the buffer.
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*
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* @param[in] buf Memory buffer to read from.
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* @param[in] bit_offset Offset in bits from the beginning of @p buf to where to
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* read from. This is interpreted differently based on @p little_endian.
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* @param[in] bit_size Number of bits to read. This must be grather than zero
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* and no more than 64.
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* @param[in] little_endian Whether the bits should be interpreted in
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* little-endian order.
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* @return The read bits in host order.
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*/
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uint64_t deserialize_bits(const void *buf, uint64_t bit_offset,
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uint8_t bit_size, bool little_endian);
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/** @} */
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#endif /* DRGN_SERIALIZE_H */
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