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      1 /* udis86 - libudis86/input.h
      2  *
      3  * Copyright (c) 2002-2009 Vivek Thampi
      4  * All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without modification,
      7  * are permitted provided that the following conditions are met:
      8  *
      9  *     * Redistributions of source code must retain the above copyright notice,
     10  *       this list of conditions and the following disclaimer.
     11  *     * Redistributions in binary form must reproduce the above copyright notice,
     12  *       this list of conditions and the following disclaimer in the documentation
     13  *       and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
     16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     18  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
     19  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     20  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     21  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
     22  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     24  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 #ifndef UD_INPUT_H
     27 #define UD_INPUT_H
     28 
     29 #include "types.h"
     30 #include "udint.h"
     31 
     32 uint8_t ud_inp_next(struct ud* u);
     33 
     34 /*
     35  * inp_start
     36  *    Should be called before each de-code operation.
     37  */
     38 static inline void
     39 inp_start(struct ud *u)
     40 {
     41   u->inp_ctr = 0;
     42 }
     43 
     44 /* inp_reset
     45  *    Resets the current pointer to its position before the current
     46  *    instruction disassembly was started.
     47  */
     48 static inline void
     49 inp_reset(struct ud *u)
     50 {
     51   u->inp_curr -= u->inp_ctr;
     52   u->inp_ctr   = 0;
     53 }
     54 
     55 /* inp_sess
     56  *    Returns the pointer to current session.
     57  */
     58 static inline uint8_t*
     59 inp_sess(struct ud *u)
     60 {
     61   return u->inp_sess;
     62 }
     63 
     64 /*
     65  * inp_curr
     66  *    Returns the current input byte.
     67  */
     68 static inline uint8_t
     69 inp_curr(const struct ud *u)
     70 {
     71   return u->inp_cache[u->inp_curr];
     72 }
     73 
     74 /*
     75  * inp_back
     76  *    Move back a single byte in the stream.
     77  */
     78 static inline void
     79 inp_back(struct ud* u)
     80 {
     81   if (u->inp_ctr > 0) {
     82     --u->inp_curr;
     83     --u->inp_ctr;
     84   }
     85 }
     86 
     87 /*
     88  * inp_peek
     89  *    Peek next byte in input.
     90  */
     91 static inline uint8_t
     92 inp_peek(struct ud* u)
     93 {
     94   uint8_t r = ud_inp_next(u);
     95   if (!u->error) {
     96       inp_back(u); /* Don't backup if there was an error */
     97   }
     98   return r;
     99 }
    100 
    101 
    102 /*
    103  * inp_len
    104  *    Returns the number of bytes input in the current
    105  *    session.
    106  */
    107 static inline size_t
    108 inp_len(const struct ud *u)
    109 {
    110   return u->inp_ctr;
    111 }
    112 
    113 #endif /* UD_INPUT_H */
    114 /*
    115 vim: set ts=2 sw=2 expandtab
    116 */
    117