git.ozlabs.org Git - ccan/blob - tools/read_config_header.c

   1 #include <ccan/grab_file/grab_file.h>
   2 #include <ccan/str/str.h>
   3 #include <ccan/str_talloc/str_talloc.h>
   4 #include <ccan/talloc/talloc.h>
   5 #include "read_config_header.h"
   6 #include "tools.h"
   7 #include <string.h>
   8 #include <err.h>
   9
  10 /* Get an identifier token. */
  11 char *get_symbol_token(void *ctx, const char **line)
  12 {
  13         unsigned int toklen;
  14         char *ret;
  15
  16         *line += strspn(*line, " \t");
  17         toklen = strspn(*line, IDENT_CHARS);
  18         if (!toklen)
  19                 return NULL;
  20         ret = talloc_strndup(ctx, *line, toklen);
  21         *line += toklen;
  22         return ret;
  23 }
  24
  25 /* Get token if it's equal to token. */
  26 bool get_token(const char **line, const char *token)
  27 {
  28         unsigned int toklen;
  29
  30         *line += strspn(*line, " \t");
  31         if (cisalnum(token[0]) || token[0] == '_')
  32                 toklen = strspn(*line, IDENT_CHARS);
  33         else {
  34                 /* FIXME: real tokenizer handles ++ and other multi-chars.  */
  35                 toklen = strlen(token);
  36         }
  37
  38         if (toklen == strlen(token) && !strncmp(*line, token, toklen)) {
  39                 *line += toklen;
  40                 return true;
  41         }
  42         return false;
  43 }
  44
  45 static char *demangle_string(char *string)
  46 {
  47         unsigned int i;
  48         const char mapfrom[] = "abfnrtv";
  49         const char mapto[] = "\a\b\f\n\r\t\v";
  50
  51         if (!strchr(string, '"'))
  52                 return NULL;
  53         string = strchr(string, '"') + 1;
  54         if (!strrchr(string, '"'))
  55                 return NULL;
  56         *strrchr(string, '"') = '\0';
  57
  58         for (i = 0; i < strlen(string); i++) {
  59                 if (string[i] == '\\') {
  60                         char repl;
  61                         unsigned len = 0;
  62                         const char *p = strchr(mapfrom, string[i+1]);
  63                         if (p) {
  64                                 repl = mapto[p - mapfrom];
  65                                 len = 1;
  66                         } else if (strlen(string+i+1) >= 3) {
  67                                 if (string[i+1] == 'x') {
  68                                         repl = (string[i+2]-'0')*16
  69                                                 + string[i+3]-'0';
  70                                         len = 3;
  71                                 } else if (cisdigit(string[i+1])) {
  72                                         repl = (string[i+2]-'0')*8*8
  73                                                 + (string[i+3]-'0')*8
  74                                                 + (string[i+4]-'0');
  75                                         len = 3;
  76                                 }
  77                         }
  78                         if (len == 0) {
  79                                 repl = string[i+1];
  80                                 len = 1;
  81                         }
  82
  83                         string[i] = repl;
  84                         memmove(string + i + 1, string + i + len + 1,
  85                                 strlen(string + i + len + 1) + 1);
  86                 }
  87         }
  88
  89         return string;
  90 }
  91
  92 char *read_config_header(const char *ccan_dir,
  93                          const char **compiler, const char **cflags,
  94                          bool verbose)
  95 {
  96         char *fname = talloc_asprintf(NULL, "%s/config.h", ccan_dir);
  97         char **lines;
  98         unsigned int i;
  99         char *config_header;
 100
 101         config_header = grab_file(NULL, fname, NULL);
 102         talloc_free(fname);
 103
 104         if (!config_header)
 105                 goto out;
 106
 107         lines = strsplit(config_header, config_header, "\n");
 108         for (i = 0; i < talloc_array_length(lines) - 1; i++) {
 109                 char *sym;
 110                 const char **line = (const char **)&lines[i];
 111
 112                 if (!get_token(line, "#"))
 113                         continue;
 114                 if (!get_token(line, "define"))
 115                         continue;
 116                 sym = get_symbol_token(lines, line);
 117                 if (streq(sym, "CCAN_COMPILER") && !compiler) {
 118                         *compiler = demangle_string(lines[i]);
 119                         if (!*compiler)
 120                                 errx(1, "%s:%u:could not parse CCAN_COMPILER",
 121                                      fname, i+1);
 122                         if (verbose)
 123                                 printf("%s: compiler set to '%s'\n",
 124                                        fname, *compiler);
 125                 } else if (streq(sym, "CCAN_CFLAGS") && !cflags) {
 126                         *cflags = demangle_string(lines[i]);
 127                         if (!*cflags)
 128                                 errx(1, "%s:%u:could not parse CCAN_CFLAGS",
 129                                      fname, i+1);
 130                         if (verbose)
 131                                 printf("%s: compiler flags set to '%s'\n",
 132                                        fname, *cflags);
 133                 }
 134         }
 135
 136 out:
 137         if (!*compiler)
 138                 *compiler = CCAN_COMPILER;
 139         if (!*cflags)
 140                 *cflags = CCAN_CFLAGS;
 141
 142         return config_header;
 143 }