| 1 | /* |
| 2 | * BabelTrace - Bitfield Type Converter |
| 3 | * |
| 4 | * Copyright (c) 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | * |
| 6 | * This library is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * This library is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with this library; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | #include <babeltrace/compiler.h> |
| 22 | #include <babeltrace/types.h> |
| 23 | #include <stdint.h> |
| 24 | |
| 25 | /* |
| 26 | * Shortcut to integer copy if we copy bit-aligned data with 0 start_offset. |
| 27 | * This skips the bitfield overhead when dealing with enumerations (which use |
| 28 | * the bitfield copy functions). |
| 29 | */ |
| 30 | extern |
| 31 | size_t integer_copy(unsigned char *dest, const struct format *fdest, |
| 32 | const unsigned char *src, const struct format *fsrc, |
| 33 | const struct type_class *type_class); |
| 34 | |
| 35 | size_t bitfield_copy(unsigned char *dest, const struct format *fdest, |
| 36 | const unsigned char *src, const struct format *fsrc, |
| 37 | const struct type_class *type_class) |
| 38 | { |
| 39 | struct type_class_bitfield *bitfield_class = |
| 40 | container_of(type_class, struct type_class_bitfield, p); |
| 41 | struct type_class_integer *int_class = &bitfield_class->p; |
| 42 | |
| 43 | if (!(int_class->p.alignment % CHAR_BIT) |
| 44 | && !(int_class->len % CHAR_BIT) |
| 45 | && !(bitfield_class->start_offset % CHAR_BIT)) { |
| 46 | size_t offset = bitfield_class->start_offset / CHAR_BIT; |
| 47 | dest += offset; |
| 48 | src += offset; |
| 49 | return integer_copy(dest, fdest, src, fsrc, type_class); |
| 50 | } |
| 51 | |
| 52 | if (!int_class->signedness) { |
| 53 | uint64_t v; |
| 54 | |
| 55 | v = fsrc->bitfield_unsigned_read(src, |
| 56 | bitfield_class->start_offset, |
| 57 | int_class->len, |
| 58 | int_class->byte_order); |
| 59 | return fdest->bitfield_unsigned_write(dest, |
| 60 | bitfield_class->start_offset, |
| 61 | int_class->len, int_class->byte_order, |
| 62 | v); |
| 63 | } else { |
| 64 | int64_t v; |
| 65 | |
| 66 | v = fsrc->bitfield_signed_read(src, |
| 67 | bitfield_class->start_offset, |
| 68 | int_class->len, |
| 69 | int_class->byte_order); |
| 70 | return fdest->bitfield_signed_write(dest, |
| 71 | bitfield_class->start_offset, |
| 72 | int_class->len, int_class->byte_order, |
| 73 | v); |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | void bitfield_type_free(struct type_class_bitfield *bitfield_class) |
| 78 | { |
| 79 | g_free(bitfield_class); |
| 80 | } |
| 81 | |
| 82 | static void _bitfield_type_free(struct type_class *type_class) |
| 83 | { |
| 84 | struct type_class_bitfield *bitfield_class = |
| 85 | container_of(type_class, struct type_class_bitfield, p); |
| 86 | bitfield_type_free(bitfield_class); |
| 87 | } |
| 88 | |
| 89 | struct type_class_bitfield *bitfield_type_new(const char *name, |
| 90 | size_t start_offset, |
| 91 | size_t len, int byte_order, |
| 92 | int signedness, |
| 93 | size_t alignment) |
| 94 | { |
| 95 | struct type_class_bitfield *bitfield_class; |
| 96 | struct type_class_integer *int_class; |
| 97 | int ret; |
| 98 | |
| 99 | bitfield_class = g_new(struct type_class_bitfield, 1); |
| 100 | int_class = &bitfield_class->p; |
| 101 | int_class->p.name = g_quark_from_string(name); |
| 102 | int_class->p.alignment = alignment; |
| 103 | int_class->p.copy = bitfield_copy; |
| 104 | int_class->p.free = _bitfield_type_free; |
| 105 | int_class->len = len; |
| 106 | int_class->byte_order = byte_order; |
| 107 | int_class->signedness = signedness; |
| 108 | bitfield_class->start_offset = start_offset; |
| 109 | if (int_class->p.name) { |
| 110 | ret = ctf_register_type(&int_class->p); |
| 111 | if (ret) { |
| 112 | g_free(bitfield_class); |
| 113 | return NULL; |
| 114 | } |
| 115 | } |
| 116 | return bitfield_class; |
| 117 | } |