switch capture by ref

4 files changed, 54 insertions, 14 deletions

diff --git a/bootstrap/all.h b/bootstrap/all.h
index 6055a07..3145674 100644
--- a/bootstrap/all.h
+++ b/bootstrap/all.h
@@ -403,8 +403,9 @@ struct iswitchcase {
 
 struct euswitchcase {
    const char *capt;
-   int captid;
-   int vval;
+   bool captptr;
+   int captid, vval;
+   const struct type *captty;
    struct aggfield *fld;
    struct blockstmt t;
 };
@@ -436,6 +437,7 @@ struct stmt {
          struct expr test;
          slice_t(struct euswitchcase) cs;
          struct blockstmt *f;
+         bool byptr;
       } euswitch;
       struct expr *retex;
    };
diff --git a/bootstrap/cgen.c b/bootstrap/cgen.c
index 31f2235..8e2fef9 100644
--- a/bootstrap/cgen.c
+++ b/bootstrap/cgen.c
@@ -368,17 +368,34 @@ genstmt(struct stmt *stmt) {
       pri("}\n");
       break;
    case Seuswitch:
-      pri("{ %t __stmp = %e;\n", stmt->euswitch.test.ty, &stmt->euswitch.test);
-      pri("switch (__stmp.t) {", &stmt->euswitch.test);
-      for (int i = 0; i < stmt->euswitch.cs.n; ++i) {
-         struct euswitchcase c = stmt->euswitch.cs.d[i];
-         pri("case /* %s */ %d: ", c.fld->name, c.vval);
-         if (c.capt)
-            pri("{ %t %s_%d = __stmp.u.%s;\n", c.fld->ty, c.capt, c.captid, c.fld->name);
-         genblock(c.t);
-         if (c.capt)
-            pri("}\n");
-         pri("break;\n");
+      if (!stmt->euswitch.byptr) {
+         pri("{ %t __stmp = %e;\n", stmt->euswitch.test.ty, &stmt->euswitch.test);
+         pri("switch (__stmp.t) {", &stmt->euswitch.test);
+         for (int i = 0; i < stmt->euswitch.cs.n; ++i) {
+            struct euswitchcase c = stmt->euswitch.cs.d[i];
+            pri("case /* %s */ %d: ", c.fld->name, c.vval);
+            if (c.capt)
+               pri("{ %t %s_%d = __stmp.u.%s;\n", c.fld->ty, c.capt, c.captid, c.fld->name);
+            genblock(c.t);
+            if (c.capt)
+               pri("}\n");
+            pri("break;\n");
+         }
+      } else {
+         pri("{ %t *__stmp = &%e;\n", stmt->euswitch.test.ty, &stmt->euswitch.test);
+         pri("switch (__stmp->t) {", &stmt->euswitch.test);
+         for (int i = 0; i < stmt->euswitch.cs.n; ++i) {
+            struct euswitchcase c = stmt->euswitch.cs.d[i];
+            pri("case /* %s */ %d: ", c.fld->name, c.vval);
+            if (c.capt && c.captptr)
+               pri("{ %t %s_%d = &__stmp->u.%s;\n", c.captty, c.capt, c.captid, c.fld->name);
+            if (c.capt && !c.captptr)
+               pri("{ %t %s_%d = __stmp->u.%s;\n", c.captty, c.capt, c.captid, c.fld->name);
+            genblock(c.t);
+            if (c.capt)
+               pri("}\n");
+            pri("break;\n");
+         }
       }
       if (stmt->iswitch.f) {
          pri("default: ");
diff --git a/bootstrap/parse.c b/bootstrap/parse.c
index cd41b47..59d3b5f 100644
--- a/bootstrap/parse.c
+++ b/bootstrap/parse.c
@@ -808,6 +808,8 @@ islvalue(const struct expr *ex) {
       return 1;
    if (ex->t == Eindex || ex->t == Eget)
       return 1;
+   if (ex->t == Eini)
+      return 1;
    return 0;
 }
 
@@ -1970,16 +1972,33 @@ psteuswitch(struct parser *P, const struct expr *test) {
          c.vval = c.fld - test->ty->agg.flds.d;
          if (!c.fld)
             fatal(P, tok.span, "%t has no such variant %T", test->ty, tok);
+         if (c.fld->ty && lexmatch(P, &tok, '*')) {
+            if (!islvalue(test)) {
+               fatal(P, tok.span, "cannot capture by pointer, test expression is not lvalue");
+            }
+            c.captptr = 1;
+            st.euswitch.byptr = 1;
+            if (lexpeek(P).t != TKident)
+               lexexpect(P, TKident);
+         }
          if (c.fld->ty && lexmatch(P, &tok, TKident)) {
             struct env env = {P->curenv};
+            const struct type *ty = c.fld->ty;
+
             c.capt = tok.str;
+            if (c.captptr) {
+               ty = interntype((struct type) {
+                  TYptr, g_targ.ptrsize, .child = test->ty->konst ? constify(ty) : ty
+               });
+            }
             pushenv(P, &env);
             putdecl(P, tok.span, &(struct decl) {
                Dlet, c.capt, .span = tok.span, .var = {
-                  c.fld->ty, NULL, c.captid = P->varid++, P->curfn->id
+                  c.captty = ty, NULL, c.captid = P->varid++, P->curfn->id
                }
             });
          }
+         lexexpect(P, ';');
          c.t = parseblock0(P);
          if (c.capt)
             popenv(P);
diff --git a/bootstrap/test2.cff b/bootstrap/test2.cff
index 4690f72..c0fafc5 100644
--- a/bootstrap/test2.cff
+++ b/bootstrap/test2.cff
@@ -37,6 +37,8 @@ extern fn main() void {
    case None;
    case Int i;
       i;
+   case Flo *f;
+      *f += 1.0f;
    }
 
    printf("n %d\n", n.value);