npp.c

   1 /*
   2  * neatpp - a small and simple C preprocessor
   3  *
   4  * Copyright (C) 2010-2011 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 <stdio.h>
  11 #include <string.h>
  12 #include <stdlib.h>
  13 #include <unistd.h>
  14 #include <sys/stat.h>
  15 #include "tok.h"
  16
  17 #define OBUFSZ          (1 << 19)
  18
  19 static int rmcomments(char *d, char *s, int l)
  20 {
  21         char *e = s + l;
  22         char *d1 = d;
  23         char *r = s;
  24         while (r < e) {
  25                 if (r + 3 < e && r[0] == '/' && r[1] == '*') {
  26                         memcpy(d, s, r - s);
  27                         d += r - s;
  28                         while (r + 1 < e) {
  29                                 r++;
  30                                 if (r[0] == '*' && r[1] == '/') {
  31                                         r++;
  32                                         break;
  33                                 }
  34                         }
  35                         s = r + 1;
  36                 }
  37                 if (r + 1 < e && (r[0] == '\'' || r[0] == '"')) {
  38                         char c = r[0];
  39                         r++;
  40                         while (r < e && *r != c) {
  41                                 if (*r == '\\')
  42                                         r++;
  43                                 r++;
  44                         }
  45                 }
  46                 r++;
  47         }
  48         memcpy(d, s, e - s);
  49         d += e - s;
  50         return d - d1;
  51 }
  52
  53 static int xwrite(int fd, char *buf, int len)
  54 {
  55         int nw = 0;
  56         while (nw < len) {
  57                 int ret = write(fd, buf + nw, len - nw);
  58                 if (ret == -1 && (errno == EAGAIN || errno == EINTR))
  59                         continue;
  60                 if (ret < 0)
  61                         break;
  62                 nw += ret;
  63         }
  64         return nw;
  65 }
  66
  67 int main(int argc, char *argv[])
  68 {
  69         int ofd = 1;
  70         int i = 1;
  71         char *s1, *s2;
  72         int nr;
  73         int len = 0;
  74         while (i < argc && argv[i][0] == '-') {
  75                 if (argv[i][1] == 'I')
  76                         cpp_addpath(argv[i][2] ? argv[i] + 2 : argv[++i]);
  77                 if (argv[i][1] == 'D') {
  78                         char *name = argv[i] + 2;
  79                         char *def = "";
  80                         char *eq = strchr(name, '=');
  81                         if (eq) {
  82                                 *eq = '\0';
  83                                 def = eq + 1;
  84                         }
  85                         cpp_define(name, def);
  86                 }
  87                 i++;
  88         }
  89         if (i + 1 >= argc) {
  90                 printf("usage: npp [-I idir] [-D define] input output\n");
  91                 return 0;
  92         }
  93         if (cpp_init(argv[i++]))
  94                 die("npp: cannot open input file\n");
  95         ofd = open(argv[i++], O_WRONLY | O_TRUNC | O_CREAT, 0600);
  96         if (ofd < 0)
  97                 die("npp: cannot open output file\n");
  98         s1 = malloc(OBUFSZ);
  99         s2 = malloc(OBUFSZ);
 100         if (!s1 || !s2)
 101                 die("npp: cannot allocate enough memory\n");
 102         while ((nr = cpp_read(s1 + len)) >= 0)
 103                 len += nr;
 104         len = rmcomments(s2, s1, len);
 105         xwrite(ofd, s2, len);
 106         close(ofd);
 107         return 0;
 108 }