First working monomorphic type-reflection.

Author: graydon

src/rustc/front/intrinsic.rs

@@ -18,6 +18,7 @@ mod intrinsic {
     }
 
     iface ty_visitor {
+        fn visit_bot();
         fn visit_nil();
         fn visit_bool();
 
@@ -36,6 +37,8 @@ mod intrinsic {
         fn visit_float();
         fn visit_f32();
         fn visit_f64();
+
+        fn visit_char();
         fn visit_str();
 
         fn visit_vec(cells_mut: bool,
@@ -68,6 +71,7 @@ mod intrinsic {
     iface val_visitor {
 
         // Basic types we can visit directly.
+        fn visit_bot();
         fn visit_nil();
         fn visit_bool(b: &bool);
 
@@ -87,6 +91,8 @@ mod intrinsic {
         fn visit_f32(f: &f32);
         fn visit_f64(f: &f64);
 
+        fn visit_char(c: &char);
+
         // Vecs and strs we can provide a stub view of.
         fn visit_str(repr: &vec::unsafe::vec_repr,
                      visit_cell: fn(uint,self));

src/rustc/middle/trans/native.rs

@@ -782,7 +782,7 @@ fn trans_intrinsic(ccx: @crate_ctxt, decl: ValueRef, item: @ast::native_item,
                    ref_id: option<ast::node_id>) {
     let fcx = new_fn_ctxt_w_id(ccx, path, decl, item.id,
                                some(substs), some(item.span));
-    let bcx = top_scope_block(fcx, none), lltop = bcx.llbb;
+    let mut bcx = top_scope_block(fcx, none), lltop = bcx.llbb;
     let tp_ty = substs.tys[0], lltp_ty = type_of::type_of(ccx, tp_ty);
     alt check item.ident {
       "size_of" {
@@ -835,27 +835,83 @@ fn trans_intrinsic(ccx: @crate_ctxt, decl: ValueRef, item: @ast::native_item,
               fcx.llretptr);
       }
       "visit_ty" {
-        let vp_ty = substs.tys[1], _llvp_ty = type_of::type_of(ccx, vp_ty);
+
+        // signature: fn visit_ty<T,V:ty_visitor>(tv: V);
+
+        let tp_ty = substs.tys[0];
+        let vp_ty = substs.tys[1];
         let visitor = get_param(decl, first_real_arg);
-        // FIXME: implement a proper iface-call. Nontrivial.
-        Call(bcx, visitor, []);
+
+        // We're going to synthesize a monomorphized vtbl call here much
+        // like what impl::trans_monomorphized_callee does, but without
+        // having quite as much source machinery to go on.
+
+        alt impl::find_vtable_in_fn_ctxt(substs,
+                                         1u, /* n_param */
+                                         0u  /* n_bound */ ) {
+
+          typeck::vtable_static(impl_did, impl_substs, sub_origins) {
+
+            let (tyname, args) = alt ty::get(tp_ty).struct {
+              ty::ty_bot { ("bot", []) }
+              ty::ty_nil { ("nil", []) }
+              ty::ty_bool { ("bool", []) }
+              ty::ty_int(ast::ty_i) { ("int", []) }
+              ty::ty_int(ast::ty_char) { ("char", []) }
+              ty::ty_int(ast::ty_i8) { ("i8", []) }
+              ty::ty_int(ast::ty_i16) { ("i16", []) }
+              ty::ty_int(ast::ty_i32) { ("i32", []) }
+              ty::ty_int(ast::ty_i64) { ("i64", []) }
+              ty::ty_uint(ast::ty_u) { ("uint", []) }
+              ty::ty_uint(ast::ty_u8) { ("u8", []) }
+              ty::ty_uint(ast::ty_u16) { ("u16", []) }
+              ty::ty_uint(ast::ty_u32) { ("u32", []) }
+              ty::ty_uint(ast::ty_u64) { ("u64", []) }
+              ty::ty_float(ast::ty_f) { ("float", []) }
+              ty::ty_float(ast::ty_f32) { ("f32", []) }
+              ty::ty_float(ast::ty_f64) { ("f64", []) }
+              ty::ty_str { ("str", []) }
+              _ {
+                bcx.sess().unimpl("trans::native::visit_ty on "
+                                  + ty_to_str(ccx.tcx, tp_ty));
+              }
+            };
+
+            let mth_id = impl::method_with_name(ccx, impl_did,
+                                                "visit_" + tyname);
+            let mth_ty = ty::lookup_item_type(ccx.tcx, mth_id).ty;
+
+            // FIXME: is this safe? There is no callee AST node,
+            // we're synthesizing it.
+            let callee_id = (-1) as ast::node_id;
+
+            let dest = ignore;
+
+            bcx = trans_call_inner(bcx,
+                                   mth_ty,
+                                   ty::mk_nil(ccx.tcx),
+                                   {|bcx|
+                                       let lval =
+                                           lval_static_fn_inner
+                                           (bcx, mth_id, callee_id,
+                                            impl_substs,  some(sub_origins));
+                                       {env: self_env(visitor, vp_ty, none)
+                                        with lval}
+                                   }, arg_vals(args), dest);
+          }
+          _ {
+            ccx.sess.span_bug(item.span,
+                              "non-static callee in 'visit_ty' intrinsinc");
+          }
+        }
       }
 
       "visit_val" {
-        let vp_ty = substs.tys[1], _llvp_ty = type_of::type_of(ccx, vp_ty);
-        let val = get_param(decl, first_real_arg);
-        let visitor = get_param(decl, first_real_arg + 1u);
-        // FIXME: implement a proper iface-call. Nontrivial.
-        Call(bcx, visitor, [val]);
+        bcx.sess().unimpl("trans::native::visit_val");
       }
 
       "visit_val_pair" {
-        let vp_ty = substs.tys[1], _llvp_ty = type_of::type_of(ccx, vp_ty);
-        let a = get_param(decl, first_real_arg);
-        let b = get_param(decl, first_real_arg + 1u);
-        let visitor = get_param(decl, first_real_arg + 2u);
-        // FIXME: implement a proper iface-call. Nontrivial.
-        Call(bcx, visitor, [a, b]);
+        bcx.sess().unimpl("trans::native::visit_val_pair");
       }
     }
     build_return(bcx);

src/rustc/middle/trans/type_use.rs

@@ -76,9 +76,9 @@ fn type_uses_for(ccx: @crate_ctxt, fn_id: def_id, n_tps: uint)
       ast_map::node_native_item(i@@{node: native_item_fn(_, _), _}, abi, _) {
         if abi == native_abi_rust_intrinsic {
             let flags = alt check i.ident {
-              "size_of" |
-              "pref_align_of" | "min_align_of" | "init" |
-              "reinterpret_cast" { use_repr }
+              "visit_ty" | "visit_val" | "visit_val_pair" { 3u }
+              "size_of" |  "pref_align_of" | "min_align_of" |
+              "init" |  "reinterpret_cast" { use_repr }
               "get_tydesc" | "needs_drop" { use_tydesc }
               "forget" | "addr_of" { 0u }
             };

src/test/run-pass/reflect-visit-type.rs

@@ -0,0 +1,130 @@
+// xfail-test
+//
+// This works on stage2 currently. Once we have a snapshot
+// and some fiddling with inject_intrinsic (and possibly another
+// snapshot after _that_) it can be un-xfailed and changed
+// to use the intrinsic:: interface and native module.
+//
+
+iface ty_visitor {
+    fn visit_bot();
+    fn visit_nil();
+    fn visit_bool();
+
+    fn visit_int();
+    fn visit_i8();
+    fn visit_i16();
+    fn visit_i32();
+    fn visit_i64();
+
+    fn visit_uint();
+    fn visit_u8();
+    fn visit_u16();
+    fn visit_u32();
+    fn visit_u64();
+
+    fn visit_float();
+    fn visit_f32();
+    fn visit_f64();
+
+    fn visit_char();
+    fn visit_str();
+
+    fn visit_vec(cells_mut: bool,
+                 visit_cell: fn(uint, self));
+
+    fn visit_box(inner_mut: bool,
+                 visit_inner: fn(self));
+
+    fn visit_uniq(inner_mut: bool,
+                  visit_inner: fn(self));
+
+    fn visit_ptr(inner_mut: bool,
+                 visit_inner: fn(self));
+
+    fn visit_rptr(inner_mut: bool,
+                  visit_inner: fn(self));
+
+    fn visit_rec(n_fields: uint,
+                 field_name: fn(uint) -> str/&,
+                 field_mut: fn(uint) -> bool,
+                 visit_field: fn(uint, self));
+    fn visit_tup(n_fields: uint,
+                 visit_field: fn(uint, self));
+    fn visit_enum(n_variants: uint,
+                  variant: uint,
+                  variant_name: fn(uint) -> str/&,
+                  visit_variant: fn(uint, self));
+}
+
+enum my_visitor = { mut types: [str] };
+
+impl of ty_visitor for my_visitor {
+    fn visit_bot() { self.types += ["bot"] }
+    fn visit_nil() { self.types += ["nil"] }
+    fn visit_bool() { self.types += ["bool"] }
+
+    fn visit_int() { self.types += ["int"] }
+    fn visit_i8() { self.types += ["i8"] }
+    fn visit_i16() { self.types += ["i16"] }
+    fn visit_i32() { }
+    fn visit_i64() { }
+
+    fn visit_uint() { }
+    fn visit_u8() { }
+    fn visit_u16() { }
+    fn visit_u32() { }
+    fn visit_u64() { }
+
+    fn visit_float() { }
+    fn visit_f32() { }
+    fn visit_f64() { }
+
+    fn visit_char() { }
+    fn visit_str() { }
+
+    fn visit_vec(_cells_mut: bool,
+                 _visit_cell: fn(uint, my_visitor)) { }
+
+    fn visit_box(_inner_mut: bool,
+                 _visit_inner: fn(my_visitor)) { }
+
+    fn visit_uniq(_inner_mut: bool,
+                  _visit_inner: fn(my_visitor)) { }
+
+    fn visit_ptr(_inner_mut: bool,
+                 _visit_inner: fn(my_visitor)) { }
+
+    fn visit_rptr(_inner_mut: bool,
+                  _visit_inner: fn(my_visitor)) { }
+
+    fn visit_rec(_n_fields: uint,
+                 _field_name: fn(uint) -> str/&,
+                 _field_mut: fn(uint) -> bool,
+                 _visit_field: fn(uint, my_visitor)) { }
+    fn visit_tup(_n_fields: uint,
+                 _visit_field: fn(uint, my_visitor)) { }
+    fn visit_enum(_n_variants: uint,
+                  _variant: uint,
+                  _variant_name: fn(uint) -> str/&,
+                  _visit_variant: fn(uint, my_visitor)) { }
+}
+
+#[abi = "rust-intrinsic"]
+native mod rusti {
+    fn visit_ty<T,V:ty_visitor>(tv: V);
+}
+
+fn main() {
+    let v = my_visitor({mut types: []});
+
+    rusti::visit_ty::<bool,my_visitor>(v);
+    rusti::visit_ty::<int,my_visitor>(v);
+    rusti::visit_ty::<i8,my_visitor>(v);
+    rusti::visit_ty::<i16,my_visitor>(v);
+
+    for v.types.each {|s|
+        io::println(#fmt("type: %s", s));
+    }
+    assert v.types == ["bool", "int", "i8", "i16"];
+}