widl: Add support for '%' operator in expressions.

tools/widl/header.c

@@ -520,6 +520,7 @@ void write_expr(FILE *h, const expr_t *e, int brackets)
     break;
   case EXPR_SHL:
   case EXPR_SHR:
+  case EXPR_MOD:
   case EXPR_MUL:
   case EXPR_DIV:
   case EXPR_ADD:
@@ -533,6 +534,7 @@ void write_expr(FILE *h, const expr_t *e, int brackets)
     switch (e->type) {
     case EXPR_SHL: fprintf(h, " << "); break;
     case EXPR_SHR: fprintf(h, " >> "); break;
+    case EXPR_MOD: fprintf(h, " %% "); break;
     case EXPR_MUL: fprintf(h, " * "); break;
     case EXPR_DIV: fprintf(h, " / "); break;
     case EXPR_ADD: fprintf(h, " + "); break;

tools/widl/parser.y

@@ -293,7 +293,7 @@ static void add_explicit_handle_if_necessary(func_t *func);
 %left '|'
 %left '&'
 %left '-' '+'
-%left '*' '/'
+%left '*' '/' '%'
 %left SHL SHR
 %left '.' MEMBERPTR '[' ']'
 %right '~'
@@ -632,6 +632,7 @@ expr:	  aNUM					{ $$ = make_exprl(EXPR_NUM, $1); }
 	| expr '&' expr				{ $$ = make_expr2(EXPR_AND, $1, $3); }
 	| expr '+' expr				{ $$ = make_expr2(EXPR_ADD, $1, $3); }
 	| expr '-' expr				{ $$ = make_expr2(EXPR_SUB, $1, $3); }
+	| expr '%' expr				{ $$ = make_expr2(EXPR_MOD, $1, $3); }
 	| expr '*' expr				{ $$ = make_expr2(EXPR_MUL, $1, $3); }
 	| expr '/' expr				{ $$ = make_expr2(EXPR_DIV, $1, $3); }
 	| expr SHL expr				{ $$ = make_expr2(EXPR_SHL, $1, $3); }
@@ -1238,6 +1239,13 @@ static expr_t *make_expr2(enum expr_type type, expr_t *expr1, expr_t *expr2)
     case EXPR_SUB:
       e->cval = expr1->cval - expr2->cval;
       break;
+    case EXPR_MOD:
+      if (expr2->cval == 0) {
+        error_loc("divide by zero in expression\n");
+        e->cval = 0;
+      } else
+        e->cval = expr1->cval % expr2->cval;
+      break;
     case EXPR_MUL:
       e->cval = expr1->cval * expr2->cval;
       break;

tools/widl/typegen.c

@@ -352,6 +352,7 @@ static int compare_expr(const expr_t *a, const expr_t *b)
         case EXPR_AND:
         case EXPR_ADD:
         case EXPR_SUB:
+        case EXPR_MOD:
         case EXPR_MUL:
         case EXPR_DIV:
         case EXPR_SHL:
@@ -3148,6 +3149,7 @@ static void write_struct_expr(FILE *h, const expr_t *e, int brackets,
             break;
         case EXPR_SHL:
         case EXPR_SHR:
+        case EXPR_MOD:
         case EXPR_MUL:
         case EXPR_DIV:
         case EXPR_ADD:
@@ -3161,6 +3163,7 @@ static void write_struct_expr(FILE *h, const expr_t *e, int brackets,
             switch (e->type) {
                 case EXPR_SHL: fprintf(h, " << "); break;
                 case EXPR_SHR: fprintf(h, " >> "); break;
+                case EXPR_MOD: fprintf(h, " %% "); break;
                 case EXPR_MUL: fprintf(h, " * "); break;
                 case EXPR_DIV: fprintf(h, " / "); break;
                 case EXPR_ADD: fprintf(h, " + "); break;

tools/widl/widltypes.h

@@ -164,6 +164,7 @@ enum expr_type
     EXPR_MEMBERPTR,
     EXPR_MEMBER,
     EXPR_ARRAY,
+    EXPR_MOD,
 };
 
 enum type_kind