src/parse-decl.c

   1 /*
   2  *  Parse and validate C declarations.
   3  *  Copyright © 2011 Nick Bowler
   4  *
   5  *  This program is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 #include <stdio.h>
  19 #include <assert.h>
  20
  21 #include "cdecl.h"
  22 #include "typemap.h"
  23 #include "parse.h"
  24 #include "scan.h"
  25
  26 static int verify_declspecs(struct cdecl_declspec *s)
  27 {
  28         unsigned num_storage = 0;
  29         unsigned long typemap;
  30
  31         typemap = cdecl__build_typemap(s);
  32         if (typemap == -1)
  33                 return -1;
  34
  35         for (struct cdecl_declspec *c = s; c; c = c->next) {
  36                 switch (cdecl_spec_kind(c)) {
  37                 case CDECL_SPEC_TYPE:
  38                         continue;
  39                 case CDECL_SPEC_STOR:
  40                         if (++num_storage > 1) {
  41                                 fprintf(stderr, "too many storage-class specifiers\n");
  42                                 return -1;
  43                         }
  44                         break;
  45                 case CDECL_SPEC_QUAL:
  46                         /*
  47                          * Restrict qualifiers are only valid in the
  48                          * pointer qualifier list, which isn't checked here.
  49                          */
  50                         if (c->type == CDECL_QUAL_RESTRICT) {
  51                                 fprintf(stderr, "only pointer types can be restrict-qualified.\n");
  52                                 return -1;
  53                         }
  54                         break;
  55                 case CDECL_SPEC_FUNC:
  56                         /*
  57                          * We don't support functions yet.
  58                          */
  59                         fprintf(stderr, "only function declarations may have function specifiers.\n");
  60                         return -1;
  61                 default:
  62                         assert(0);
  63                 }
  64         }
  65
  66         return 0;
  67 }
  68
  69 static int verify_decl(struct cdecl *decl)
  70 {
  71         return verify_declspecs(decl->specifiers);
  72 }
  73
  74 struct cdecl *cdecl_parse_decl(const char *declstr)
  75 {
  76         YY_BUFFER_STATE state;
  77         struct cdecl *decl;
  78         int rc;
  79
  80         state = yy_scan_string(declstr);
  81         rc = yyparse(&decl);
  82         yy_delete_buffer(state);
  83
  84         if (rc != 0)
  85                 return NULL;
  86
  87         rc = verify_decl(decl);
  88         if (rc != 0) {
  89                 cdecl_free(decl);
  90                 return NULL;
  91         }
  92
  93         return decl;
  94 }