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

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