1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/compiler-init/scexpand.c	Thu Jul 13 20:03:46 2006 +0000
     1.3 @@ -0,0 +1,68 @@
     1.4 +/* expand.c -- Byte Pair Encoding decompression */
     1.5 +/* Copyright 1996 Philip Gage */
     1.6 +
     1.7 +/* Byte Pair Compression appeared in the September 1997
     1.8 + * issue of C/C++ Users Journal. The original source code
     1.9 + * may still be found at the web site of the magazine
    1.10 + * (www.cuj.com).
    1.11 + *
    1.12 + * The decompressor has been modified by me (Thiadmer
    1.13 + * Riemersma) to accept a string as input, instead of a
    1.14 + * complete file.
    1.15 + */
    1.16 +#include <assert.h>
    1.17 +#include <stdio.h>
    1.18 +#include "sc.h"
    1.19 +
    1.20 +#define STACKSIZE 16
    1.21 +
    1.22 +SC_FUNC int strexpand(char *dest, unsigned char *source, int maxlen, unsigned char pairtable[128][2])
    1.23 +{
    1.24 +  unsigned char stack[STACKSIZE];
    1.25 +  short c, top = 0;
    1.26 +  int len;
    1.27 +
    1.28 +  assert(maxlen > 0);
    1.29 +  len = 1;              /* already 1 byte for '\0' */
    1.30 +  for (;;) {
    1.31 +
    1.32 +    /* Pop byte from stack or read byte from the input string */
    1.33 +    if (top)
    1.34 +      c = stack[--top];
    1.35 +    else if ((c = *(unsigned char *)source++) == '\0')
    1.36 +      break;
    1.37 +
    1.38 +    /* Push pair on stack or output byte to the output string */
    1.39 +    if (c > 127) {
    1.40 +      assert(top+2 <= STACKSIZE);
    1.41 +      stack[top++] = pairtable[c-128][1];
    1.42 +      stack[top++] = pairtable[c-128][0];
    1.43 +    }
    1.44 +    else {
    1.45 +      len++;
    1.46 +      if (maxlen > 1) { /* reserve one byte for the '\0' */
    1.47 +        *dest++ = (char)c;
    1.48 +        maxlen--;
    1.49 +      }
    1.50 +    }
    1.51 +  }
    1.52 +  *dest = '\0';
    1.53 +  return len;           /* return number of bytes decoded */
    1.54 +}
    1.55 +
    1.56 +#if 0 /*for testing*/
    1.57 +#include "sc5.scp"
    1.58 +
    1.59 +int main (int argc, char **argv)
    1.60 +{
    1.61 +  int i;
    1.62 +  char str[128];
    1.63 +
    1.64 +  for (i=0; i<58; i++) {
    1.65 +    strexpand(str, errmsg[i], sizeof str, SCPACK_TABLE);
    1.66 +    printf("%s", str);
    1.67 +  } /* for */
    1.68 +  return 0;
    1.69 +}
    1.70 +#endif
    1.71 +