src/lib/lttng-ctl/filter-bytecode.h

   1 #ifndef _FILTER_BYTECODE_H
   2 #define _FILTER_BYTECODE_H
   3
   4 /*
   5  * filter-bytecode.h
   6  *
   7  * LTTng filter bytecode
   8  *
   9  * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  *
  11  * This library is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU Lesser General Public License, version 2.1 only,
  13  * as published by the Free Software Foundation.
  14  *
  15  * This library is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this library; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 #include "filter-ast.h"
  26
  27 /*
  28  * offsets are absolute from start of bytecode.
  29  */
  30
  31 enum filter_register {
  32         REG_R0 = 0,
  33         REG_R1 = 1,
  34         REG_ERROR,
  35 };
  36
  37 enum field_ref_type {
  38         FIELD_REF_UNKNOWN = 0,
  39         FIELD_REF_STRING,
  40         FIELD_REF_SEQUENCE,
  41         FIELD_REF_S64,
  42 };
  43
  44 struct field_ref {
  45         /* Initially, symbol offset. After link, field offset. */
  46         uint16_t offset;
  47         uint8_t type;   /* enum field_ref_type */
  48 } __attribute__((packed));
  49
  50 struct literal_numeric {
  51         int64_t v;
  52 } __attribute__((packed));
  53
  54 struct literal_string {
  55         char string[0];
  56 } __attribute__((packed));
  57
  58 enum filter_op {
  59         FILTER_OP_UNKNOWN = 0,
  60
  61         FILTER_OP_RETURN,
  62
  63         /* binary */
  64         FILTER_OP_MUL,
  65         FILTER_OP_DIV,
  66         FILTER_OP_MOD,
  67         FILTER_OP_PLUS,
  68         FILTER_OP_MINUS,
  69         FILTER_OP_RSHIFT,
  70         FILTER_OP_LSHIFT,
  71         FILTER_OP_BIN_AND,
  72         FILTER_OP_BIN_OR,
  73         FILTER_OP_BIN_XOR,
  74         FILTER_OP_EQ,
  75         FILTER_OP_NE,
  76         FILTER_OP_GT,
  77         FILTER_OP_LT,
  78         FILTER_OP_GE,
  79         FILTER_OP_LE,
  80
  81         /* unary */
  82         FILTER_OP_UNARY_PLUS,
  83         FILTER_OP_UNARY_MINUS,
  84         FILTER_OP_UNARY_NOT,
  85
  86         /* logical */
  87         FILTER_OP_AND,
  88         FILTER_OP_OR,
  89
  90         /* load */
  91         FILTER_OP_LOAD_FIELD_REF,
  92         FILTER_OP_LOAD_STRING,
  93         FILTER_OP_LOAD_S64,
  94
  95         NR_FILTER_OPS,
  96 };
  97
  98 typedef uint8_t filter_opcode_t;
  99
 100 struct load_op {
 101         filter_opcode_t op;
 102         uint8_t reg;            /* enum filter_register */
 103         char data[0];
 104         /* data to load. Size known by enum filter_opcode and null-term char. */
 105 } __attribute__((packed));
 106
 107 struct binary_op {
 108         filter_opcode_t op;
 109 } __attribute__((packed));
 110
 111 struct unary_op {
 112         filter_opcode_t op;
 113         uint8_t reg;            /* enum filter_register */
 114 } __attribute__((packed));
 115
 116 /* skip_offset is absolute from start of bytecode */
 117 struct logical_op {
 118         filter_opcode_t op;
 119         uint16_t skip_offset;   /* bytecode insn, if skip second test */
 120 } __attribute__((packed));
 121
 122 struct return_op {
 123         filter_opcode_t op;
 124 } __attribute__((packed));
 125
 126 /*
 127  * The reloc table is located at the end of the bytecode. It is made of
 128  * tuples: (uint16_t, var. len. string). It starts at
 129  * reloc_table_offset.
 130  */
 131 struct filter_bytecode {
 132         uint16_t len;
 133         uint16_t reloc_table_offset;
 134         char data[0];
 135 };
 136
 137 struct filter_bytecode_alloc {
 138         uint16_t alloc_len;
 139         struct filter_bytecode b;
 140 };
 141
 142 static inline
 143 unsigned int bytecode_get_len(struct filter_bytecode *bytecode)
 144 {
 145         return bytecode->len;
 146 }
 147
 148 #endif /* _FILTER_BYTECODE_H */