+++ /dev/null
-#ifndef _BABELTRACE_BITFIELD_H
-#define _BABELTRACE_BITFIELD_H
-
-/*
- * Copyright 2010-2019 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-#include <stdint.h> /* C99 5.2.4.2 Numerical limits */
-#include <stdbool.h> /* C99 7.16 bool type */
-#include <babeltrace/compat/limits-internal.h> /* C99 5.2.4.2 Numerical limits */
-#include <babeltrace/endian-internal.h> /* Non-standard BIG_ENDIAN, LITTLE_ENDIAN, BYTE_ORDER */
-
-/*
- * This header strictly follows the C99 standard, except for use of the
- * compiler-specific __typeof__.
- */
-
-/*
- * This bitfield header requires the compiler representation of signed
- * integers to be two's complement.
- */
-#if (-1 != ~0)
-#error "bitfield.h requires the compiler representation of signed integers to be two's complement."
-#endif
-
-/*
- * _bt_is_signed_type() willingly generates comparison of unsigned
- * expression < 0, which is always false. Silence compiler warnings.
- */
-#ifdef __GNUC__
-# define _BT_DIAG_PUSH _Pragma("GCC diagnostic push")
-# define _BT_DIAG_POP _Pragma("GCC diagnostic pop")
-
-# define _BT_DIAG_STRINGIFY_1(x) #x
-# define _BT_DIAG_STRINGIFY(x) _BT_DIAG_STRINGIFY_1(x)
-
-# define _BT_DIAG_IGNORE(option) \
- _Pragma(_BT_DIAG_STRINGIFY(GCC diagnostic ignored option))
-# define _BT_DIAG_IGNORE_TYPE_LIMITS _BT_DIAG_IGNORE("-Wtype-limits")
-#else
-# define _BT_DIAG_PUSH
-# define _BT_DIAG_POP
-# define _BT_DIAG_IGNORE
-#endif
-
-#define _bt_is_signed_type(type) ((type) -1 < (type) 0)
-
-/*
- * Produce a build-time error if the condition `cond` is non-zero.
- * Evaluates as a size_t expression.
- */
-#define _BT_BUILD_ASSERT(cond) \
- sizeof(struct { int f:(2 * !!(cond) - 1); })
-
-/*
- * Cast value `v` to an unsigned integer of the same size as `v`.
- */
-#define _bt_cast_value_to_unsigned(v) \
- (sizeof(v) == sizeof(uint8_t) ? (uint8_t) (v) : \
- sizeof(v) == sizeof(uint16_t) ? (uint16_t) (v) : \
- sizeof(v) == sizeof(uint32_t) ? (uint32_t) (v) : \
- sizeof(v) == sizeof(uint64_t) ? (uint64_t) (v) : \
- _BT_BUILD_ASSERT(sizeof(v) <= sizeof(uint64_t)))
-
-/*
- * Cast value `v` to an unsigned integer type of the size of type `type`
- * *without* sign-extension.
- *
- * The unsigned cast ensures that we're not shifting a negative value,
- * which is undefined in C. However, this limits the maximum type size
- * of `type` to 64-bit. Generate a compile-time error if the size of
- * `type` is larger than 64-bit.
- */
-#define _bt_cast_value_to_unsigned_type(type, v) \
- (sizeof(type) == sizeof(uint8_t) ? \
- (uint8_t) _bt_cast_value_to_unsigned(v) : \
- sizeof(type) == sizeof(uint16_t) ? \
- (uint16_t) _bt_cast_value_to_unsigned(v) : \
- sizeof(type) == sizeof(uint32_t) ? \
- (uint32_t) _bt_cast_value_to_unsigned(v) : \
- sizeof(type) == sizeof(uint64_t) ? \
- (uint64_t) _bt_cast_value_to_unsigned(v) : \
- _BT_BUILD_ASSERT(sizeof(v) <= sizeof(uint64_t)))
-
-/*
- * _bt_fill_mask evaluates to a "type" integer with all bits set.
- */
-#define _bt_fill_mask(type) ((type) ~(type) 0)
-
-/*
- * Left shift a value `v` of `shift` bits.
- *
- * The type of `v` can be signed or unsigned integer.
- * The value of `shift` must be less than the size of `v` (in bits),
- * otherwise the behavior is undefined.
- * Evaluates to the result of the shift operation.
- *
- * According to the C99 standard, left shift of a left hand-side signed
- * type is undefined if it has a negative value or if the result cannot
- * be represented in the result type. This bitfield header discards the
- * bits that are left-shifted beyond the result type representation,
- * which is the behavior of an unsigned type left shift operation.
- * Therefore, always perform left shift on an unsigned type.
- *
- * This macro should not be used if `shift` can be greater or equal than
- * the bitwidth of `v`. See `_bt_safe_lshift`.
- */
-#define _bt_lshift(v, shift) \
- ((__typeof__(v)) (_bt_cast_value_to_unsigned(v) << (shift)))
-
-/*
- * Generate a mask of type `type` with the `length` least significant bits
- * cleared, and the most significant bits set.
- */
-#define _bt_make_mask_complement(type, length) \
- _bt_lshift(_bt_fill_mask(type), length)
-
-/*
- * Generate a mask of type `type` with the `length` least significant bits
- * set, and the most significant bits cleared.
- */
-#define _bt_make_mask(type, length) \
- ((type) ~_bt_make_mask_complement(type, length))
-
-/*
- * Right shift a value `v` of `shift` bits.
- *
- * The type of `v` can be signed or unsigned integer.
- * The value of `shift` must be less than the size of `v` (in bits),
- * otherwise the behavior is undefined.
- * Evaluates to the result of the shift operation.
- *
- * According to the C99 standard, right shift of a left hand-side signed
- * type which has a negative value is implementation defined. This
- * bitfield header relies on the right shift implementation carrying the
- * sign bit. If the compiler implementation has a different behavior,
- * emulate carrying the sign bit.
- *
- * This macro should not be used if `shift` can be greater or equal than
- * the bitwidth of `v`. See `_bt_safe_rshift`.
- */
-#if ((-1 >> 1) == -1)
-#define _bt_rshift(v, shift) ((v) >> (shift))
-#else
-#define _bt_rshift(v, shift) \
- ((__typeof__(v)) ((_bt_cast_value_to_unsigned(v) >> (shift)) | \
- ((v) < 0 ? _bt_make_mask_complement(__typeof__(v), \
- sizeof(v) * CHAR_BIT - (shift)) : 0)))
-#endif
-
-/*
- * Right shift a signed or unsigned integer with `shift` value being an
- * arbitrary number of bits. `v` is modified by this macro. The shift
- * is transformed into a sequence of `_nr_partial_shifts` consecutive
- * shift operations, each of a number of bits smaller than the bitwidth
- * of `v`, ending with a shift of the number of left over bits.
- */
-#define _bt_safe_rshift(v, shift) \
-do { \
- unsigned long _nr_partial_shifts = (shift) / (sizeof(v) * CHAR_BIT - 1); \
- unsigned long _leftover_bits = (shift) % (sizeof(v) * CHAR_BIT - 1); \
- \
- for (; _nr_partial_shifts; _nr_partial_shifts--) \
- (v) = _bt_rshift(v, sizeof(v) * CHAR_BIT - 1); \
- (v) = _bt_rshift(v, _leftover_bits); \
-} while (0)
-
-/*
- * Left shift a signed or unsigned integer with `shift` value being an
- * arbitrary number of bits. `v` is modified by this macro. The shift
- * is transformed into a sequence of `_nr_partial_shifts` consecutive
- * shift operations, each of a number of bits smaller than the bitwidth
- * of `v`, ending with a shift of the number of left over bits.
- */
-#define _bt_safe_lshift(v, shift) \
-do { \
- unsigned long _nr_partial_shifts = (shift) / (sizeof(v) * CHAR_BIT - 1); \
- unsigned long _leftover_bits = (shift) % (sizeof(v) * CHAR_BIT - 1); \
- \
- for (; _nr_partial_shifts; _nr_partial_shifts--) \
- (v) = _bt_lshift(v, sizeof(v) * CHAR_BIT - 1); \
- (v) = _bt_lshift(v, _leftover_bits); \
-} while (0)
-
-/*
- * bt_bitfield_write - write integer to a bitfield in native endianness
- *
- * Save integer to the bitfield, which starts at the "start" bit, has "len"
- * bits.
- * The inside of a bitfield is from high bits to low bits.
- * Uses native endianness.
- * For unsigned "v", pad MSB with 0 if bitfield is larger than v.
- * For signed "v", sign-extend v if bitfield is larger than v.
- *
- * On little endian, bytes are placed from the less significant to the most
- * significant. Also, consecutive bitfields are placed from lower bits to higher
- * bits.
- *
- * On big endian, bytes are places from most significant to less significant.
- * Also, consecutive bitfields are placed from higher to lower bits.
- */
-
-#define _bt_bitfield_write_le(ptr, type, start, length, v) \
-do { \
- __typeof__(v) _v = (v); \
- type *_ptr = (void *) (ptr); \
- unsigned long _start = (start), _length = (length); \
- type _mask, _cmask; \
- unsigned long _ts = sizeof(type) * CHAR_BIT; /* type size */ \
- unsigned long _start_unit, _end_unit, _this_unit; \
- unsigned long _end, _cshift; /* _cshift is "complement shift" */ \
- \
- if (!_length) \
- break; \
- \
- _end = _start + _length; \
- _start_unit = _start / _ts; \
- _end_unit = (_end + (_ts - 1)) / _ts; \
- \
- /* Trim v high bits */ \
- if (_length < sizeof(_v) * CHAR_BIT) \
- _v &= _bt_make_mask(__typeof__(_v), _length); \
- \
- /* We can now append v with a simple "or", shift it piece-wise */ \
- _this_unit = _start_unit; \
- if (_start_unit == _end_unit - 1) { \
- _mask = _bt_make_mask(type, _start % _ts); \
- if (_end % _ts) \
- _mask |= _bt_make_mask_complement(type, _end % _ts); \
- _cmask = _bt_lshift((type) (_v), _start % _ts); \
- _cmask &= ~_mask; \
- _ptr[_this_unit] &= _mask; \
- _ptr[_this_unit] |= _cmask; \
- break; \
- } \
- if (_start % _ts) { \
- _cshift = _start % _ts; \
- _mask = _bt_make_mask(type, _cshift); \
- _cmask = _bt_lshift((type) (_v), _cshift); \
- _cmask &= ~_mask; \
- _ptr[_this_unit] &= _mask; \
- _ptr[_this_unit] |= _cmask; \
- _bt_safe_rshift(_v, _ts - _cshift); \
- _start += _ts - _cshift; \
- _this_unit++; \
- } \
- for (; _this_unit < _end_unit - 1; _this_unit++) { \
- _ptr[_this_unit] = (type) _v; \
- _bt_safe_rshift(_v, _ts); \
- _start += _ts; \
- } \
- if (_end % _ts) { \
- _mask = _bt_make_mask_complement(type, _end % _ts); \
- _cmask = (type) _v; \
- _cmask &= ~_mask; \
- _ptr[_this_unit] &= _mask; \
- _ptr[_this_unit] |= _cmask; \
- } else \
- _ptr[_this_unit] = (type) _v; \
-} while (0)
-
-#define _bt_bitfield_write_be(ptr, type, start, length, v) \
-do { \
- __typeof__(v) _v = (v); \
- type *_ptr = (void *) (ptr); \
- unsigned long _start = (start), _length = (length); \
- type _mask, _cmask; \
- unsigned long _ts = sizeof(type) * CHAR_BIT; /* type size */ \
- unsigned long _start_unit, _end_unit, _this_unit; \
- unsigned long _end, _cshift; /* _cshift is "complement shift" */ \
- \
- if (!_length) \
- break; \
- \
- _end = _start + _length; \
- _start_unit = _start / _ts; \
- _end_unit = (_end + (_ts - 1)) / _ts; \
- \
- /* Trim v high bits */ \
- if (_length < sizeof(_v) * CHAR_BIT) \
- _v &= _bt_make_mask(__typeof__(_v), _length); \
- \
- /* We can now append v with a simple "or", shift it piece-wise */ \
- _this_unit = _end_unit - 1; \
- if (_start_unit == _end_unit - 1) { \
- _mask = _bt_make_mask(type, (_ts - (_end % _ts)) % _ts); \
- if (_start % _ts) \
- _mask |= _bt_make_mask_complement(type, _ts - (_start % _ts)); \
- _cmask = _bt_lshift((type) (_v), (_ts - (_end % _ts)) % _ts); \
- _cmask &= ~_mask; \
- _ptr[_this_unit] &= _mask; \
- _ptr[_this_unit] |= _cmask; \
- break; \
- } \
- if (_end % _ts) { \
- _cshift = _end % _ts; \
- _mask = _bt_make_mask(type, _ts - _cshift); \
- _cmask = _bt_lshift((type) (_v), _ts - _cshift); \
- _cmask &= ~_mask; \
- _ptr[_this_unit] &= _mask; \
- _ptr[_this_unit] |= _cmask; \
- _bt_safe_rshift(_v, _cshift); \
- _end -= _cshift; \
- _this_unit--; \
- } \
- for (; (long) _this_unit >= (long) _start_unit + 1; _this_unit--) { \
- _ptr[_this_unit] = (type) _v; \
- _bt_safe_rshift(_v, _ts); \
- _end -= _ts; \
- } \
- if (_start % _ts) { \
- _mask = _bt_make_mask_complement(type, _ts - (_start % _ts)); \
- _cmask = (type) _v; \
- _cmask &= ~_mask; \
- _ptr[_this_unit] &= _mask; \
- _ptr[_this_unit] |= _cmask; \
- } else \
- _ptr[_this_unit] = (type) _v; \
-} while (0)
-
-/*
- * bt_bitfield_write - write integer to a bitfield in native endianness
- * bt_bitfield_write_le - write integer to a bitfield in little endian
- * bt_bitfield_write_be - write integer to a bitfield in big endian
- */
-
-#if (BYTE_ORDER == LITTLE_ENDIAN)
-
-#define bt_bitfield_write(ptr, type, start, length, v) \
- _bt_bitfield_write_le(ptr, type, start, length, v)
-
-#define bt_bitfield_write_le(ptr, type, start, length, v) \
- _bt_bitfield_write_le(ptr, type, start, length, v)
-
-#define bt_bitfield_write_be(ptr, type, start, length, v) \
- _bt_bitfield_write_be(ptr, unsigned char, start, length, v)
-
-#elif (BYTE_ORDER == BIG_ENDIAN)
-
-#define bt_bitfield_write(ptr, type, start, length, v) \
- _bt_bitfield_write_be(ptr, type, start, length, v)
-
-#define bt_bitfield_write_le(ptr, type, start, length, v) \
- _bt_bitfield_write_le(ptr, unsigned char, start, length, v)
-
-#define bt_bitfield_write_be(ptr, type, start, length, v) \
- _bt_bitfield_write_be(ptr, type, start, length, v)
-
-#else /* (BYTE_ORDER == PDP_ENDIAN) */
-
-#error "Byte order not supported"
-
-#endif
-
-#define _bt_bitfield_read_le(ptr, type, start, length, vptr) \
-do { \
- __typeof__(*(vptr)) *_vptr = (vptr); \
- __typeof__(*_vptr) _v; \
- type *_ptr = (void *) (ptr); \
- unsigned long _start = (start), _length = (length); \
- type _mask, _cmask; \
- unsigned long _ts = sizeof(type) * CHAR_BIT; /* type size */ \
- unsigned long _start_unit, _end_unit, _this_unit; \
- unsigned long _end, _cshift; /* _cshift is "complement shift" */ \
- bool _is_signed_type; \
- \
- if (!_length) { \
- *_vptr = 0; \
- break; \
- } \
- \
- _end = _start + _length; \
- _start_unit = _start / _ts; \
- _end_unit = (_end + (_ts - 1)) / _ts; \
- \
- _this_unit = _end_unit - 1; \
- _BT_DIAG_PUSH \
- _BT_DIAG_IGNORE_TYPE_LIMITS \
- _is_signed_type = _bt_is_signed_type(__typeof__(_v)); \
- _BT_DIAG_POP \
- if (_is_signed_type \
- && (_ptr[_this_unit] & _bt_lshift((type) 1, (_end % _ts ? _end % _ts : _ts) - 1))) \
- _v = ~(__typeof__(_v)) 0; \
- else \
- _v = 0; \
- if (_start_unit == _end_unit - 1) { \
- _cmask = _ptr[_this_unit]; \
- _cmask = _bt_rshift(_cmask, _start % _ts); \
- if ((_end - _start) % _ts) { \
- _mask = _bt_make_mask(type, _end - _start); \
- _cmask &= _mask; \
- } \
- _bt_safe_lshift(_v, _end - _start); \
- _v |= _bt_cast_value_to_unsigned_type(__typeof__(_v), _cmask); \
- *_vptr = _v; \
- break; \
- } \
- if (_end % _ts) { \
- _cshift = _end % _ts; \
- _mask = _bt_make_mask(type, _cshift); \
- _cmask = _ptr[_this_unit]; \
- _cmask &= _mask; \
- _bt_safe_lshift(_v, _cshift); \
- _v |= _bt_cast_value_to_unsigned_type(__typeof__(_v), _cmask); \
- _end -= _cshift; \
- _this_unit--; \
- } \
- for (; (long) _this_unit >= (long) _start_unit + 1; _this_unit--) { \
- _bt_safe_lshift(_v, _ts); \
- _v |= _bt_cast_value_to_unsigned_type(__typeof__(_v), _ptr[_this_unit]); \
- _end -= _ts; \
- } \
- if (_start % _ts) { \
- _mask = _bt_make_mask(type, _ts - (_start % _ts)); \
- _cmask = _ptr[_this_unit]; \
- _cmask = _bt_rshift(_cmask, _start % _ts); \
- _cmask &= _mask; \
- _bt_safe_lshift(_v, _ts - (_start % _ts)); \
- _v |= _bt_cast_value_to_unsigned_type(__typeof__(_v), _cmask); \
- } else { \
- _bt_safe_lshift(_v, _ts); \
- _v |= _bt_cast_value_to_unsigned_type(__typeof__(_v), _ptr[_this_unit]); \
- } \
- *_vptr = _v; \
-} while (0)
-
-#define _bt_bitfield_read_be(ptr, type, start, length, vptr) \
-do { \
- __typeof__(*(vptr)) *_vptr = (vptr); \
- __typeof__(*_vptr) _v; \
- type *_ptr = (void *) (ptr); \
- unsigned long _start = (start), _length = (length); \
- type _mask, _cmask; \
- unsigned long _ts = sizeof(type) * CHAR_BIT; /* type size */ \
- unsigned long _start_unit, _end_unit, _this_unit; \
- unsigned long _end, _cshift; /* _cshift is "complement shift" */ \
- bool _is_signed_type; \
- \
- if (!_length) { \
- *_vptr = 0; \
- break; \
- } \
- \
- _end = _start + _length; \
- _start_unit = _start / _ts; \
- _end_unit = (_end + (_ts - 1)) / _ts; \
- \
- _this_unit = _start_unit; \
- _BT_DIAG_PUSH \
- _BT_DIAG_IGNORE_TYPE_LIMITS \
- _is_signed_type = _bt_is_signed_type(__typeof__(_v)); \
- _BT_DIAG_POP \
- if (_is_signed_type \
- && (_ptr[_this_unit] & _bt_lshift((type) 1, _ts - (_start % _ts) - 1))) \
- _v = ~(__typeof__(_v)) 0; \
- else \
- _v = 0; \
- if (_start_unit == _end_unit - 1) { \
- _cmask = _ptr[_this_unit]; \
- _cmask = _bt_rshift(_cmask, (_ts - (_end % _ts)) % _ts); \
- if ((_end - _start) % _ts) { \
- _mask = _bt_make_mask(type, _end - _start); \
- _cmask &= _mask; \
- } \
- _bt_safe_lshift(_v, _end - _start); \
- _v |= _bt_cast_value_to_unsigned_type(__typeof__(_v), _cmask); \
- *_vptr = _v; \
- break; \
- } \
- if (_start % _ts) { \
- _cshift = _start % _ts; \
- _mask = _bt_make_mask(type, _ts - _cshift); \
- _cmask = _ptr[_this_unit]; \
- _cmask &= _mask; \
- _bt_safe_lshift(_v, _ts - _cshift); \
- _v |= _bt_cast_value_to_unsigned_type(__typeof__(_v), _cmask); \
- _start += _ts - _cshift; \
- _this_unit++; \
- } \
- for (; _this_unit < _end_unit - 1; _this_unit++) { \
- _bt_safe_lshift(_v, _ts); \
- _v |= _bt_cast_value_to_unsigned_type(__typeof__(_v), _ptr[_this_unit]); \
- _start += _ts; \
- } \
- if (_end % _ts) { \
- _mask = _bt_make_mask(type, _end % _ts); \
- _cmask = _ptr[_this_unit]; \
- _cmask = _bt_rshift(_cmask, _ts - (_end % _ts)); \
- _cmask &= _mask; \
- _bt_safe_lshift(_v, _end % _ts); \
- _v |= _bt_cast_value_to_unsigned_type(__typeof__(_v), _cmask); \
- } else { \
- _bt_safe_lshift(_v, _ts); \
- _v |= _bt_cast_value_to_unsigned_type(__typeof__(_v), _ptr[_this_unit]); \
- } \
- *_vptr = _v; \
-} while (0)
-
-/*
- * bt_bitfield_read - read integer from a bitfield in native endianness
- * bt_bitfield_read_le - read integer from a bitfield in little endian
- * bt_bitfield_read_be - read integer from a bitfield in big endian
- */
-
-#if (BYTE_ORDER == LITTLE_ENDIAN)
-
-#define bt_bitfield_read(ptr, type, start, length, vptr) \
- _bt_bitfield_read_le(ptr, type, start, length, vptr)
-
-#define bt_bitfield_read_le(ptr, type, start, length, vptr) \
- _bt_bitfield_read_le(ptr, type, start, length, vptr)
-
-#define bt_bitfield_read_be(ptr, type, start, length, vptr) \
- _bt_bitfield_read_be(ptr, unsigned char, start, length, vptr)
-
-#elif (BYTE_ORDER == BIG_ENDIAN)
-
-#define bt_bitfield_read(ptr, type, start, length, vptr) \
- _bt_bitfield_read_be(ptr, type, start, length, vptr)
-
-#define bt_bitfield_read_le(ptr, type, start, length, vptr) \
- _bt_bitfield_read_le(ptr, unsigned char, start, length, vptr)
-
-#define bt_bitfield_read_be(ptr, type, start, length, vptr) \
- _bt_bitfield_read_be(ptr, type, start, length, vptr)
-
-#else /* (BYTE_ORDER == PDP_ENDIAN) */
-
-#error "Byte order not supported"
-
-#endif
-
-#endif /* _BABELTRACE_BITFIELD_H */
projects / babeltrace.git / blobdiff