ccache/comments.c
2010-02-17 21:03:27 +01:00

139 lines
2.7 KiB
C

/*
* Copyright (C) Joel Rosdahl 2009
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 675 Mass
* Ave, Cambridge, MA 02139, USA.
*/
#include "ccache.h"
#include "comments.h"
#include <unistd.h>
#include <sys/mman.h>
#define HASH(ch) \
do { \
hashbuf[hashbuflen] = ch; \
hashbuflen++; \
if (hashbuflen == sizeof(hashbuf)) { \
hash_buffer(hash, hashbuf, sizeof(hashbuf)); \
hashbuflen = 0; \
} \
} while (0)
void hash_string_ignoring_comments(
struct mdfour *hash, const char *str, size_t len)
{
const char *p;
const char *end;
char hashbuf[64];
size_t hashbuflen = 0;
p = str;
end = str + len;
while (1) {
if (p >= end) {
goto end;
}
switch (*p) {
case '/':
if (p+1 == end) {
break;
}
switch (*(p+1)) {
case '*':
HASH(' '); /* Don't paste tokens together when
* removing the comment. */
p += 2;
while (p+1 < end
&& (*p != '*' || *(p+1) != '/')) {
if (*p == '\n') {
/* Keep line numbers. */
HASH('\n');
}
p++;
}
if (p+1 == end) {
goto end;
}
p += 2;
continue;
case '/':
p += 2;
while (p < end
&& (*p != '\n' || *(p-1) == '\\')) {
p++;
}
continue;
default:
break;
}
break;
case '"':
HASH(*p);
p++;
while (p < end && (*p != '"' || *(p-1) == '\\')) {
HASH(*p);
p++;
}
if (p == end) {
goto end;
}
break;
default:
break;
}
HASH(*p);
p++;
}
end:
hash_buffer(hash, hashbuf, hashbuflen);
}
/*
* Add contents of a file to a hash, but don't hash comments. Returns 1 on
* success, otherwise 0.
*/
int hash_file_ignoring_comments(struct mdfour *hash, const char *path)
{
int fd;
struct stat st;
char *data;
fd = open(path, O_RDONLY);
if (fd == -1) {
return 0;
}
if (fstat(fd, &st) == -1) {
close(fd);
return 0;
}
data = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
if (data == (void *)-1) {
return 0;
}
hash_string_ignoring_comments(hash, data, st.st_size);
munmap(data, st.st_size);
return 1;
}