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Bind types when resolving them.

--- a/parse/infer.c

+++ b/parse/infer.c

@@ -41,6 +41,10 @@

 static void infernode(Inferstate *st, Node *n, Type *ret, int *sawret);

 static void inferexpr(Inferstate *st, Node *n, Type *ret, int *sawret);

 static void typesub(Inferstate *st, Node *n);

+static void tybind(Inferstate *st, Type *t);

+static void bind(Inferstate *st, Node *n);

+static void tyunbind(Inferstate *st, Type *t);

+static void unbind(Inferstate *st, Node *n);

 static Type *unify(Inferstate *st, Node *ctx, Type *a, Type *b);

 static Type *tf(Inferstate *st, Type *t);

@@ -227,6 +231,7 @@

     if (t->resolved)

         return;

     t->resolved = 1;

+    tybind(st, t);

     /* if this is a generic type, bind the params. */

     /* Walk through aggregate type members */

     if (t->type == Tystruct) {

@@ -256,6 +261,7 @@

         t->cstrs = bsdup(base->cstrs);

     if (tyinfinite(st, t, NULL))

         fatal(t->line, "Type %s includes itself", tystr(t));

+    tyunbind(st, t);

 }

 /* fixd the most accurate type mapping we have (ie,

@@ -355,7 +361,7 @@

 /* Binds the type parameters present in the

  * current type into the type environment */

-static void tybind(Inferstate *st, Htab *bt, Type *t)

+static void putbindings(Inferstate *st, Htab *bt, Type *t)

 {

     size_t i;

@@ -371,11 +377,23 @@

     htput(bt, t->pname, t);

     for (i = 0; i < t->nparam; i++)

-        tybind(st, bt, t->param[i]);

+        putbindings(st, bt, t->param[i]);

     for (i = 0; i < t->nsub; i++)

-        tybind(st, bt, t->sub[i]);

+        putbindings(st, bt, t->sub[i]);

 }

+static void tybind(Inferstate *st, Type *t)

+{

+    Htab *bt;

+

+    if (t->type != Tygeneric)

+        return;

+    st->ingeneric++;

+    bt = mkht(strhash, streq);

+    lappend(&st->tybindings, &st->ntybindings, bt);

+    putbindings(st, bt, t);

+}

+

 /* Binds the type parameters in the

  * declaration into the type environment */

 static void bind(Inferstate *st, Node *n)

@@ -388,11 +406,12 @@

     if (!n->decl.init)

         fatal(n->line, "generic %s has no initializer", n->decl);

+    st->ingeneric++;

     bt = mkht(strhash, streq);

     lappend(&st->tybindings, &st->ntybindings, bt);

-    tybind(st, bt, n->decl.type);

-    tybind(st, bt, n->decl.init->expr.type);

+    putbindings(st, bt, n->decl.type);

+    putbindings(st, bt, n->decl.init->expr.type);

 }

 /* Rolls back the binding of type parameters in

@@ -403,8 +422,18 @@

         return;

     htfree(st->tybindings[st->ntybindings - 1]);

     lpop(&st->tybindings, &st->ntybindings);

+    st->ingeneric--;

 }

+static void tyunbind(Inferstate *st, Type *t)

+{

+    if (t->type != Tygeneric)

+        return;

+    htfree(st->tybindings[st->ntybindings - 1]);

+    lpop(&st->tybindings, &st->ntybindings);

+    st->ingeneric--;

+}

+

 static void checkcast(Inferstate *st, Node *n)

 {

     /* FIXME: actually verify the casts. Right now, it's ok to leave this

@@ -1044,15 +1073,11 @@

             popstab();

             break;

         case Ndecl:

-            if (n->decl.isgeneric)

-                st->ingeneric++;

             bind(st, n);

             inferdecl(st, n);

             unbind(st, n);

             if (type(st, n)->type == Typaram && !st->ingeneric)

                 fatal(n->line, "Generic type %s in non-generic near %s\n", tystr(type(st, n)), ctxstr(st, n));

-            if (n->decl.isgeneric)

-                st->ingeneric--;

             break;

         case Nblock:

             setsuper(n->block.scope, curstab());

@@ -1098,7 +1123,7 @@

             setsuper(n->func.scope, curstab());

             if (st->ntybindings > 0)

                 for (i = 0; i < n->func.nargs; i++)

-                    tybind(st, st->tybindings[st->ntybindings - 1], n->func.args[i]->decl.type);

+                    putbindings(st, st->tybindings[st->ntybindings - 1], n->func.args[i]->decl.type);

             pushstab(n->func.scope);

             inferstab(st, n->block.scope);

             inferfunc(st, n);