git.ozlabs.org Git - ccan/blob - tools/ccanlint/idempotent.c

   1 #include "ccanlint.h"
   2 #include <ccan/talloc/talloc.h>
   3 #include <ccan/str/str.h>
   4 #include <sys/types.h>
   5 #include <sys/stat.h>
   6 #include <fcntl.h>
   7 #include <unistd.h>
   8 #include <limits.h>
   9 #include <errno.h>
  10 #include <stdlib.h>
  11 #include <stdio.h>
  12 #include <err.h>
  13 #include <string.h>
  14 #include <ctype.h>
  15 #include "../tools.h"
  16
  17 static const char explain[]
  18 = "Headers usually start with the C preprocessor lines to prevent multiple\n"
  19   "inclusions.  These look like the following:\n"
  20   "#ifndef MY_HEADER_H\n"
  21   "#define MY_HEADER_H\n"
  22   "...\n"
  23   "#endif /* MY_HEADER_H */\n";
  24
  25 static char *get_ifndef_sym(char *line)
  26 {
  27         line += strspn(line, SPACE_CHARS);
  28         if (line[0] == '#')
  29         {
  30                 line++;
  31                 line += strspn(line, SPACE_CHARS);
  32                 if (strstarts(line, "ifndef") && isspace(line[6]))
  33                         return line+6+strspn(line+6, SPACE_CHARS);
  34                 else if (strstarts(line, "if"))
  35                 {
  36                         line += 2;
  37                         line += strspn(line, SPACE_CHARS);
  38                         if (line[0] == '!')
  39                         {
  40                                 line++;
  41                                 line += strspn(line, SPACE_CHARS);
  42                                 if (strstarts(line, "defined"))
  43                                 {
  44                                         line += 7;
  45                                         line += strspn(line, SPACE_CHARS);
  46                                         if (line[0] == '(')
  47                                         {
  48                                                 line++;
  49                                                 line += strspn(line,
  50                                                         SPACE_CHARS);
  51                                         }
  52                                         return line;
  53                                 }
  54                         }
  55                 }
  56         }
  57         return NULL;
  58 }
  59
  60 static int is_define(char *line, char *id, size_t id_len)
  61 {
  62         line += strspn(line, SPACE_CHARS);
  63         if (line[0] == '#')
  64         {
  65                 line++;
  66                 line += strspn(line, SPACE_CHARS);
  67                 if (strstarts(line, "define") && isspace(line[6]))
  68                 {
  69                         line += 6;
  70                         line += strspn(line, SPACE_CHARS);
  71                         if (strspn(line, IDENT_CHARS) == id_len &&
  72                             memcmp(id, line, id_len) == 0)
  73                                 return 1;
  74                 }
  75         }
  76         return 0;
  77 }
  78
  79 static char *report_idem(struct ccan_file *f, char *sofar)
  80 {
  81         char **lines;
  82         char *id;
  83         size_t id_len;
  84
  85         lines = get_ccan_file_lines(f);
  86         if (f->num_lines < 3)
  87                 /* FIXME: We assume small headers probably uninteresting. */
  88                 return NULL;
  89
  90         id = get_ifndef_sym(lines[0]);
  91         if (!id)
  92                 return talloc_asprintf_append(sofar,
  93                         "%s:1:expect first line to be #ifndef.\n", f->name);
  94         id_len = strspn(id, IDENT_CHARS);
  95
  96         if (!is_define(lines[1], id, id_len))
  97                 return talloc_asprintf_append(sofar,
  98                         "%s:2:expect second line to be '#define %.*s'.\n",
  99                         f->name, (int)id_len, id);
 100
 101         return sofar;
 102 }
 103
 104 static void *check_idempotent(struct manifest *m)
 105 {
 106         struct ccan_file *f;
 107         char *report = NULL;
 108
 109         list_for_each(&m->h_files, f, list)
 110                 report = report_idem(f, report);
 111
 112         return report;
 113 }
 114
 115 static const char *describe_idempotent(struct manifest *m, void *check_result)
 116 {
 117         return talloc_asprintf(check_result,
 118                                "Some headers not idempotent:\n"
 119                                "%s\n%s", (char *)check_result,
 120                                explain);
 121 }
 122
 123 struct ccanlint idempotent = {
 124         .name = "Headers are #ifndef/#define idempotent wrapped",
 125         .total_score = 1,
 126         .check = check_idempotent,
 127         .describe = describe_idempotent,
 128 };