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

   1 #include <tools/ccanlint/ccanlint.h>
   2 #include <tools/tools.h>
   3 #include <ccan/talloc/talloc.h>
   4 #include <ccan/str/str.h>
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <fcntl.h>
   8 #include <unistd.h>
   9 #include <limits.h>
  10 #include <errno.h>
  11 #include <stdlib.h>
  12 #include <stdio.h>
  13 #include <err.h>
  14 #include <string.h>
  15 #include <ctype.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 *report_idem(struct ccan_file *f, char *sofar)
  26 {
  27         struct line_info *line_info;
  28         unsigned int i, first_preproc_line;
  29         const char *line, *sym;
  30
  31         line_info = get_ccan_line_info(f);
  32         if (f->num_lines < 3)
  33                 /* FIXME: We assume small headers probably uninteresting. */
  34                 return sofar;
  35
  36         for (i = 0; i < f->num_lines; i++) {
  37                 if (line_info[i].type == DOC_LINE
  38                     || line_info[i].type == COMMENT_LINE)
  39                         continue;
  40                 if (line_info[i].type == CODE_LINE)
  41                         return talloc_asprintf_append(sofar,
  42                               "%s:%u:expect first non-comment line to be #ifndef.\n", f->name, i+1);
  43                 else if (line_info[i].type == PREPROC_LINE)
  44                         break;
  45         }
  46
  47         /* No code at all?  Don't complain. */
  48         if (i == f->num_lines)
  49                 return sofar;
  50
  51         first_preproc_line = i;
  52         for (i = first_preproc_line+1; i < f->num_lines; i++) {
  53                 if (line_info[i].type == DOC_LINE
  54                     || line_info[i].type == COMMENT_LINE)
  55                         continue;
  56                 if (line_info[i].type == CODE_LINE)
  57                         return talloc_asprintf_append(sofar,
  58                               "%s:%u:expect second line to be #define.\n", f->name, i+1);
  59                 else if (line_info[i].type == PREPROC_LINE)
  60                         break;
  61         }
  62
  63         /* No code at all?  Weird. */
  64         if (i == f->num_lines)
  65                 return sofar;
  66
  67         /* We expect a condition on this line. */
  68         if (!line_info[i].cond) {
  69                 return talloc_asprintf_append(sofar,
  70                                               "%s:%u:expected #ifndef.\n",
  71                                               f->name, first_preproc_line+1);
  72         }
  73
  74         line = f->lines[i];
  75
  76         /* We expect the condition to be ! IFDEF <symbol>. */
  77         if (line_info[i].cond->type != PP_COND_IFDEF
  78             || !line_info[i].cond->inverse) {
  79                 return talloc_asprintf_append(sofar,
  80                                               "%s:%u:expected #ifndef.\n",
  81                                               f->name, first_preproc_line+1);
  82         }
  83
  84         /* And this to be #define <symbol> */
  85         if (!get_token(&line, "#"))
  86                 abort();
  87         if (!get_token(&line, "define")) {
  88                 return talloc_asprintf_append(sofar,
  89                               "%s:%u:expected '#define %s'.\n",
  90                               f->name, i+1, line_info[i].cond->symbol);
  91         }
  92         sym = get_symbol_token(f, &line);
  93         if (!sym || !streq(sym, line_info[i].cond->symbol)) {
  94                 return talloc_asprintf_append(sofar,
  95                               "%s:%u:expected '#define %s'.\n",
  96                               f->name, i+1, line_info[i].cond->symbol);
  97         }
  98
  99         /* Rest of code should all be covered by that conditional. */
 100         for (i++; i < f->num_lines; i++) {
 101                 unsigned int val = 0;
 102                 if (line_info[i].type == DOC_LINE
 103                     || line_info[i].type == COMMENT_LINE)
 104                         continue;
 105                 if (get_ccan_line_pp(line_info[i].cond, sym, &val, NULL)
 106                     != NOT_COMPILED)
 107                         return talloc_asprintf_append(sofar,
 108                               "%s:%u:code outside idempotent region.\n",
 109                               f->name, i+1);
 110         }
 111
 112         return sofar;
 113 }
 114
 115 static void *check_idempotent(struct manifest *m)
 116 {
 117         struct ccan_file *f;
 118         char *report = NULL;
 119
 120         list_for_each(&m->h_files, f, list)
 121                 report = report_idem(f, report);
 122
 123         return report;
 124 }
 125
 126 static const char *describe_idempotent(struct manifest *m, void *check_result)
 127 {
 128         return talloc_asprintf(check_result,
 129                                "Some headers not idempotent:\n"
 130                                "%s\n%s", (char *)check_result,
 131                                explain);
 132 }
 133
 134 struct ccanlint idempotent = {
 135         .key = "idempotent",
 136         .name = "Headers are #ifndef/#define idempotent wrapped",
 137         .total_score = 1,
 138         .check = check_idempotent,
 139         .describe = describe_idempotent,
 140 };
 141
 142 REGISTER_TEST(idempotent, NULL);