npp.c

   1 /*
   2  * neatpp - a small and simple C preprocessor
   3  *
   4  * Copyright (C) 2010-2012 Ali Gholami Rudi
   5  *
   6  * This file is released under GNU GPL version 2.
   7  */
   8 #include <errno.h>
   9 #include <fcntl.h>
  10 #include <stdarg.h>
  11 #include <stdio.h>
  12 #include <string.h>
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15 #include <sys/stat.h>
  16 #include "tok.h"
  17
  18 #define OBUFSZ          (1 << 19)
  19
  20 static int rmcomments(char *d, char *s, int l)
  21 {
  22         char *e = s + l;
  23         char *d1 = d;
  24         char *r = s;
  25         while (r < e) {
  26                 if (r + 3 < e && r[0] == '/' && r[1] == '*') {
  27                         memcpy(d, s, r - s);
  28                         d += r - s;
  29                         while (r + 1 < e) {
  30                                 r++;
  31                                 if (r[0] == '*' && r[1] == '/') {
  32                                         r++;
  33                                         break;
  34                                 }
  35                         }
  36                         s = r + 1;
  37                 }
  38                 if (r + 1 < e && (r[0] == '\'' || r[0] == '"')) {
  39                         char c = r[0];
  40                         r++;
  41                         while (r < e && *r != c) {
  42                                 if (*r == '\\')
  43                                         r++;
  44                                 r++;
  45                         }
  46                 }
  47                 r++;
  48         }
  49         memcpy(d, s, e - s);
  50         d += e - s;
  51         return d - d1;
  52 }
  53
  54 static int xwrite(int fd, char *buf, int len)
  55 {
  56         int nw = 0;
  57         while (nw < len) {
  58                 int ret = write(fd, buf + nw, len - nw);
  59                 if (ret == -1 && (errno == EAGAIN || errno == EINTR))
  60                         continue;
  61                 if (ret < 0)
  62                         break;
  63                 nw += ret;
  64         }
  65         return nw;
  66 }
  67
  68 void err(char *fmt, ...)
  69 {
  70         va_list ap;
  71         char msg[512];
  72         va_start(ap, fmt);
  73         vsprintf(msg, fmt, ap);
  74         va_end(ap);
  75         die(msg);
  76 }
  77
  78 int main(int argc, char *argv[])
  79 {
  80         int ofd = 1;
  81         int i = 1;
  82         char *s1, *s2;
  83         int nr;
  84         int len = 0;
  85         while (i < argc && argv[i][0] == '-') {
  86                 if (argv[i][1] == 'I')
  87                         cpp_addpath(argv[i][2] ? argv[i] + 2 : argv[++i]);
  88                 if (argv[i][1] == 'D') {
  89                         char *name = argv[i] + 2;
  90                         char *def = "";
  91                         char *eq = strchr(name, '=');
  92                         if (eq) {
  93                                 *eq = '\0';
  94                                 def = eq + 1;
  95                         }
  96                         cpp_define(name, def);
  97                 }
  98                 i++;
  99         }
 100         if (i + 1 >= argc) {
 101                 printf("usage: npp [-I idir] [-D define] input output\n");
 102                 return 0;
 103         }
 104         if (cpp_init(argv[i++]))
 105                 die("npp: cannot open <%s>\n", argv[i - 1]);
 106         ofd = open(argv[i++], O_WRONLY | O_TRUNC | O_CREAT, 0600);
 107         if (ofd < 0)
 108                 die("npp: cannot open <%s>\n", argv[i - 1]);
 109         s1 = malloc(OBUFSZ);
 110         s2 = malloc(OBUFSZ);
 111         if (!s1 || !s2)
 112                 die("npp: cannot allocate enough memory\n");
 113         while ((nr = cpp_read(s1 + len)) >= 0)
 114                 len += nr;
 115         len = rmcomments(s2, s1, len);
 116         xwrite(ofd, s2, len);
 117         close(ofd);
 118         return 0;
 119 }