direct access of eunion fields

1 files changed, 18 insertions, 4 deletions

diff --git a/bootstrap/parse.c b/bootstrap/parse.c
index 93a3afb..3e14dc3 100644
--- a/bootstrap/parse.c
+++ b/bootstrap/parse.c
@@ -371,6 +371,8 @@ lex(struct parser *P) {
          tok.t = '##';
       } else if (!strcmp(s, "#len")) {
          tok.t = '#len';
+      } else if (!strcmp(s, "#tag")) {
+         tok.t = '#tag';
       } else if (!strcmp(s, "#?")) {
          tok.t = '#?';
       } else if (!strncmp(s, "#:", 2)) {
@@ -1284,27 +1286,39 @@ pexpostfix(struct parser *P) {
          if (ty->t == TYarr) {
             assert(ty->length >= 0);
             ex.t = Eintlit;
-            ex.ty = ty_usize;
+            ex.ty = ty->konst ? constify(ty_usize) : ty_usize;
             ex.span = tok.span;
             ex.i = ty->length;
          } else if (ty->t == TYslice) {
             ex.child = exprdup(ex);
             ex.t = Elen;
-            ex.ty = ty_usize;
+            ex.ty = ty->konst ? constify(ty_usize) : ty_usize;
             ex.span = tok.span;
          } else {
             fatal(P, ex.span, "invalid operand to `.#len' (%t)", ex.ty);
          }
+      } else if (lexmatch (P, &tok, '#tag')) {
+         const struct type *ty = ex.ty;
+         if (ty->t == TYptr)
+            ty = ty->child;
+         if (ty->t != TYeunion)
+            fatal(P, ex.span, "invalid operand to `.#tag' (%t)", ex.ty);
+         ex.child = exprdup(ex);
+         ex.t = Eeutag;
+         ex.ty = ty->konst ? constify(ty->agg.enumty) : ty->agg.enumty;
+         ex.span = tok.span;
       } else {
          const char *fnam = (tok = lexexpect(P, TKident)).str;
          const struct type *ty = ex.ty;
          if (ty->t == TYptr)
             ty = ty->child;
-         if (ty->t == TYstruct || ty->t == TYunion) {
+         if (ty->t == TYstruct || ty->t == TYunion || ty->t == TYeunion) {
             int idx = structfldnam2idx(ty, fnam);
             struct aggfield *fld = &ty->agg.flds.d[idx];
             if (idx < 0)
                fatal(P, tok.span, "%t has no such field `%s'", ty, fnam);
+            if (!fld->ty)
+               fatal(P, tok.span, "%t variant `%s' is empty", ty, fnam);
             
             ex.get.lhs = exprdup(ex);
             ex.t = Eget;
@@ -1748,7 +1762,7 @@ parsevardecl(decl_yielder_t yield, void *yarg, struct parser *P, bool let, bool
 
       if (lexmatch(P, NULL, '=')) {
          ini = exprdup(parseexpr(P));
-         ty = ini->ty;
+         ty = unconstify(ini->ty);
       } else {
          ty = parsetype(P);
          if (lexmatch(P, NULL, '=')) {