sem.c

   1 #include <stdlib.h>
   2 #include <string.h>
   3
   4 #include "list.h"
   5 #include "sem/scc.h"
   6 #include "ast.h"
   7
   8 void type_error(const char *msg, ...)
   9 {
  10         va_list ap;
  11         va_start(ap, msg);
  12         fprintf(stderr, "type error: ");
  13         vfprintf(stderr, msg, ap);
  14         va_end(ap);
  15         die("");
  16 }
  17
  18 void check_expr_constant(struct expr *expr)
  19 {
  20         switch (expr->type) {
  21         case ebinop:
  22                 check_expr_constant(expr->data.ebinop.l);
  23                 check_expr_constant(expr->data.ebinop.r);
  24                 break;
  25         case eunop:
  26                 check_expr_constant(expr->data.eunop.l);
  27                 break;
  28         case efuncall:
  29         case eident:
  30                 type_error("Initialiser is not constant\n");
  31                 break;
  32         default:
  33                 break;
  34         }
  35 }
  36
  37 struct vardecl *type_vardecl(struct vardecl *vardecl)
  38 {
  39         return vardecl;
  40 }
  41
  42 struct decl *type_decl(struct decl *decl)
  43 {
  44         switch (decl->type) {
  45         case dcomp:
  46                 fprintf(stderr, "type_decl:component unsupported\n");
  47                 break;
  48         case dfundecl:
  49                 fprintf(stderr, "type_decl:fundecl unsupported\n");
  50                 break;
  51         case dvardecl:
  52                 decl->data.dvar = type_vardecl(decl->data.dvar);
  53                 break;
  54         }
  55         return decl;
  56 }
  57
  58 struct ast *sem(struct ast *ast)
  59 {
  60         ast = ast_scc(ast);
  61
  62         //Check that all globals are constant
  63         for (int i = 0; i<ast->ndecls; i++) {
  64                 if (ast->decls[i]->type == dvardecl) {
  65                         //Check globals
  66                         check_expr_constant(ast->decls[i]->data.dvar->expr);
  67                         break;
  68                 }
  69         }
  70         return ast;
  71 }