bobk@mntgfx.MENTOR.COM (Bob Kelley) (07/18/87)
Here's what we use at Mentor Graphics to facilitate the use of C++ on
machines where the linker does not support very long names like those
generated by C++. I hope that this C program will be useful at other
sites where C++ is used. The output of cfront is sent through this
program before it is fed to the C compiler. It would be nice to use
a pipe here, but the return code from cfront would be lost.
Watch out for the signature at the end.
/*
* police.c - Limit length of C source lines, strip comments and blank lines.
* Replace excessively long names with crc32-derived equivalents.
*
* COPYRIGHT (C) 1987 MENTOR GRAPHICS CORPORATION. ALL RIGHTS RESERVED.
* PERMISSION IS HEREBY GRANTED TO USE, DISTRIBUTE, OR MODIFY THIS PROGRAM,
* PROVIDED THAT THIS NOTICE IS REPRODUCED AND INCLUDED ON ALL COPIES AND
* MODIFICATIONS OF THE PROGRAM AND PROVIDED THIS PROGRAM IS NOT INCORPORATED
* INTO ANY COMMERCIAL PRODUCT WITHOUT THE EXPRESS WRITTEN PERMISSION OF
* MENTOR GRAPHICS CORPORATION. MENTOR GRAPHICS CORPORATION SHALL NOT BE
* RESPONSIBLE FOR ANY DAMAGES INCURRED THROUGH THE USE OF THIS PROGRAM.
* THE PROGRAM IS SUPPLIED "AS IS" AND NO WARRANTIES EXPRESS OR IMPLIED
* ARE MADE REGARDING THIS PROGRAM INCLUDING THE WARRANTY OF FITNESS FOR
* A PARTICULAR PURPOSE OR THE WARRANTY OF MERCHANTABILITY.
*/
#include <stdio.h>
#include <ctype.h>
#define HASHSIZE 509 /* size of hash table (primes work best) */
#define IDSIZE 1024 /* maximum length of any identifier */
#define LNSIZE 31 /* maximum length of linker identifiers */
#define MAXLINE 128 /* start thinking about breaking output lines */
int col = 0; /* output column, might exceed MAXLINE */
char id[IDSIZE]; /* buffer for incoming identifiers */
char *idp; /* pointer into the above buffer */
char *progname; /* the name of this program from *argv */
struct bucket { /* hash bucket structure */
struct bucket *next; /* next bucket with the same hash index */
struct bucket *alt; /* alias bucket, if any */
char flags; /* according to BUCKET_... below */
char name[1]; /* actually, these are variable size structs */
} *table[HASHSIZE]; /* the hash table */
#define BUCKET_OLD 1 /* is a generated name */
/*
* radixtab is a table of 'digits' in radix RADIX
*/
char radixtab[] = "123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
#define RADIX (sizeof(radixtab)-1)
/*
* The following code implements CRC32, used here to generate suffixes
*/
/*
* Copyright (C) 1986 Gary S. Brown. You may use this program, or
* code or tables extracted from it, as desired without restriction.
*/
/* First, the polynomial itself and its table of feedback terms. The */
/* polynomial is */
/* X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0 */
/* Note that we take it "backwards" and put the highest-order term in */
/* the lowest-order bit. The X^32 term is "implied"; the LSB is the */
/* X^31 term, etc. The X^0 term (usually shown as "+1") results in */
/* the MSB being 1. */
/* Note that the usual hardware shift register implementation, which */
/* is what we're using (we're merely optimizing it by doing eight-bit */
/* chunks at a time) shifts bits into the lowest-order term. In our */
/* implementation, that means shifting towards the right. Why do we */
/* do it this way? Because the calculated CRC must be transmitted in */
/* order from highest-order term to lowest-order term. UARTs transmit */
/* characters in order from LSB to MSB. By storing the CRC this way, */
/* we hand it to the UART in the order low-byte to high-byte; the UART */
/* sends each low-bit to hight-bit; and the result is transmission bit */
/* by bit from highest- to lowest-order term without requiring any bit */
/* shuffling on our part. Reception works similarly. */
/* The feedback terms table consists of 256, 32-bit entries. Notes: */
/* */
/* The table can be generated at runtime if desired; code to do so */
/* is shown later. It might not be obvious, but the feedback */
/* terms simply represent the results of eight shift/xor opera- */
/* tions for all combinations of data and CRC register values. */
/* */
/* The values must be right-shifted by eight bits by the "updcrc" */
/* logic; the shift must be unsigned (bring in zeroes). On some */
/* hardware you could probably optimize the shift in assembler by */
/* using byte-swap instructions. */
static unsigned long crc_32_tab[] = { /* CRC polynomial 0xedb88320 */
0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};
#define UPDC32(octet, crc) (crc_32_tab[((crc) ^ (octet)) & 0xff] ^ ((crc) >> 8))
/*
* look up an identifier in the hash table, return bucket ptr if found.
* if not found then create a new bucket and return a pointer to it.
*/
struct bucket *
lookup (id, len)
char *id;
int len;
{
register unsigned long h;
register char *p, *q;
register struct bucket *b;
for (p = id, h = 0; *p != '\0'; h <<= 1, h ^= *p++) {}
for (b = table[h %= HASHSIZE]; b; b = b->next) {
p = id;
q = b->name;
for (;;) {
if (*p == 0)
if (*q == 0)
return (b);
else
break;
else if (*q == 0)
break;
else if (*q++ != *p++)
break;
}
}
b = (struct bucket *) malloc (sizeof (struct bucket) + len + 1);
for (p = id, q = b->name; (*q++ = *p++) != '\0'; ) {}
b->next = table[h];
b->alt = NULL;
b->flags = 0;
table[h] = b;
return (b);
}
/*
* Generate an alias for a name longer than LNSIZE.
* Enter the alias in the hash table, returning the bucket pointer.
*/
struct bucket *
alias (id, len)
char *id;
int len;
{
char name[LNSIZE+1];
register unsigned long crc;
register unsigned long t;
register char *p, *q;
register int s;
register struct bucket *bp;
for (crc = 0; ; ) {
for (s = 0, p = id, q = name; s < LNSIZE; ++s)
*q++ = *p++;
*q = '\0';
for (p = id; *p; ++p)
crc = UPDC32(*p, crc);
for(t = crc; t; ) {
*--q = radixtab[t % RADIX];
t /= RADIX;
}
bp = lookup (name, LNSIZE);
if (!(bp->flags & BUCKET_OLD))
break;
fprintf (stderr, "%s: collision of name alias \"%s\"\n", progname, id);
}
bp->flags |= BUCKET_OLD;
return (bp);
}
/*
* An identifier has just been parsed from the source file.
* Remember the identifier in the hash table if it's long enough
* to collide with a generated name. If it has an alias, output
* the alias instead. If it needs an alias, generate one and
* output it instead. Otherwise, output the identifier itself.
*/
void
handle (id, len)
char *id;
int len;
{
register struct bucket *b;
register char *p;
if (len >= LNSIZE) {
b = lookup (id, len);
b->flags |= BUCKET_OLD;
if (b->alt != NULL)
b = b->alt;
else if (len > LNSIZE) {
putchar ('/');
++col;
for (p = "* police! "; *p; putchar(*p), ++p, ++col) {}
for (p = id; *p; putchar(*p), ++p, ++col) {}
for (p = " */ "; *p; putchar(*p), ++p, ++col) {}
b->alt = alias (id, len);
b = b->alt;
}
id = b->name;
}
for (p = id; *p != '\0'; putchar (*p), ++p, ++col) {}
}
/*
* A slash-slash style comment has been introduced.
* Eat characters until a newline is found.
*/
int
eatbcpl ( )
{
register int c = 0;
while (c != EOF && c != '\n')
c = getchar ( );
return (c);
}
/*
* A slash-star style comment has been introduced.
* Eat characters until the star-slash is found.
* Echo newlines so the line count is preserved.
*/
int
eatcomment ( )
{
register int c;
for(;;) {
c = getchar ( );
if (c == '*') {
c = getchar ( );
if (c == '/')
return (0);
if (c == EOF) {
return (c);
} else if (c == '\n') {
putchar (c);
col = 0;
}
} else if (c == '\n') {
putchar (c);
col = 0;
} else if (c == EOF)
return (c);
}
}
/*
* A character constant or string has been introduced with the delimiter c.
* Eat and echo characters until the delimiter is found, taking escape
* sequences into account.
*/
void
eatcc (quote)
register int quote;
{
register int peek;
putchar(quote);
++col;
for (peek = getchar ( ); peek != quote; peek = getchar ( )) {
if (peek == EOF) break;
else if (peek == '\n') break;
else if (peek == '\\') {
peek = getchar ( );
if (peek == EOF) break;
else if (peek == '\n') {
putchar ('\\');
putchar ('\n');
col = 0;
continue;
} else {
/* note: this handles \' and \" too. */
putchar ('\\');
++col;
}
}
putchar (peek);
++col;
}
}
/*
* The main program.
* This is basically a partial lexical analyzer for the C language.
* An attempt is made to break long lines after commas or semicolons.
* Duplicate blanks and tabs are squashed out, as are comments.
* Character constants and strings are carefully preserved.
* Most importantly, identifiers longer than LNSIZE are aliased.
*/
main (argc, argv)
int argc;
char *argv[];
{
register int peekc;
register int c;
progname = *argv;
for (peekc = 0;;) {
if (peekc) {
c = peekc;
peekc = 0;
} else
c = getchar ( );
switch (c) {
case EOF:
exit (0);
case ',':
case ';':
if (col > MAXLINE) {
putchar (c);
c = '\n';
col = 0;
}
break;
case '\n':
col = 0;
break;
case ' ':
case '\t':
peekc = getchar ( );
if (peekc == c)
continue;
break;
case '/':
peekc = getchar ( );
if (peekc == '/')
peekc = eatbcpl ( );
else if (peekc == '*')
peekc = eatcomment ( );
else
break;
continue;
case '"':
case '\'':
eatcc (c);
default:
if (isalpha (c) || '_' == c || c == '$') {
idp = id;
while (isalnum (c) || '_' == c || c == '$') {
if (idp >= id + IDSIZE) {
fprintf (stderr, "%s: Identifier too long.\n", progname);
exit (1);
}
*idp++ = c;
c = getchar ( );
}
peekc = c;
*idp = 0;
handle (id, idp - id);
continue;
} else
break;
}
putchar (c);
++col;
}
}
Robert J. Kelley @ Mentor Graphics Corporation
...!tektronix!sequent!mntgfx!bobk or bobk@mntgfx.MENTOR.COM
--
Robert J. Kelley
...!tektronix!sequent!mntgfx!bobk or bobk@mntgfx.MENTOR.COM