From bfdba2dbcceb33e0738949e9f4d6635f689baf1b Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Thu, 16 Dec 2010 16:34:20 -0800
Subject: [PATCH] rustc: Translate parametric function signatures into task +
 type parameters + formal arguments

---
 src/comp/middle/trans.rs  | 25 +++++++++++++++++++++++++
 src/comp/middle/typeck.rs | 27 +++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/src/comp/middle/trans.rs b/src/comp/middle/trans.rs
index b074e6d6a9e..8b094ffcca8 100644
--- a/src/comp/middle/trans.rs
+++ b/src/comp/middle/trans.rs
@@ -214,6 +214,21 @@ fn T_task() -> TypeRef {
                      ));
 }
 
+fn T_tydesc() -> TypeRef {
+    auto pvoid = T_ptr(T_i8());
+    auto glue_fn_ty = T_ptr(T_fn(vec(T_taskptr(), pvoid), T_void()));
+    ret T_struct(vec(pvoid,             // first_param
+                     T_int(),           // size
+                     T_int(),           // align
+                     glue_fn_ty,        // copy_glue_off
+                     glue_fn_ty,        // drop_glue_off
+                     glue_fn_ty,        // free_glue_off
+                     glue_fn_ty,        // sever_glue_off
+                     glue_fn_ty,        // mark_glue_off
+                     glue_fn_ty,        // obj_drop_glue_off
+                     glue_fn_ty));      // is_stateful
+}
+
 fn T_array(TypeRef t, uint n) -> TypeRef {
     ret llvm.LLVMArrayType(t, n);
 }
@@ -271,6 +286,15 @@ fn type_of_fn(@crate_ctxt cx,
               vec[typeck.arg] inputs,
               @typeck.ty output) -> TypeRef {
     let vec[TypeRef] atys = vec(T_taskptr());
+
+    auto fn_ty = typeck.plain_ty(typeck.ty_fn(inputs, output));
+    auto ty_param_count = typeck.count_ty_params(fn_ty);
+    auto i = 0u;
+    while (i < ty_param_count) {
+        atys += T_tydesc();
+        i += 1u;
+    }
+
     for (typeck.arg arg in inputs) {
         let TypeRef t = type_of(cx, arg.ty);
         alt (arg.mode) {
@@ -2614,6 +2638,7 @@ fn trans_exit_task_glue(@crate_ctxt cx) {
 fn create_typedefs(@crate_ctxt cx) {
     llvm.LLVMAddTypeName(cx.llmod, _str.buf("rust_crate"), T_crate());
     llvm.LLVMAddTypeName(cx.llmod, _str.buf("rust_task"), T_task());
+    llvm.LLVMAddTypeName(cx.llmod, _str.buf("rust_tydesc"), T_tydesc());
 }
 
 fn crate_constant(@crate_ctxt cx) -> ValueRef {
diff --git a/src/comp/middle/typeck.rs b/src/comp/middle/typeck.rs
index 26bb8871f86..b318ce33b63 100644
--- a/src/comp/middle/typeck.rs
+++ b/src/comp/middle/typeck.rs
@@ -942,6 +942,33 @@ fn ann_to_type(&ast.ann ann) -> @ty {
     }
 }
 
+fn count_ty_params(@ty t) -> uint {
+    state obj ty_param_counter(@mutable vec[ast.def_id] param_ids) {
+        fn fold_simple_ty(@ty t) -> @ty {
+            alt (t.struct) {
+                case (ty_param(?param_id)) {
+                    for (ast.def_id other_param_id in *param_ids) {
+                        if (param_id._0 == other_param_id._0 &&
+                                param_id._1 == other_param_id._1) {
+                            ret t;
+                        }
+                    }
+                    *param_ids += vec(param_id);
+                }
+                case (_) { /* fall through */ }
+            }
+            ret t;
+        }
+    }
+  
+    let vec[ast.def_id] param_ids_inner = vec();
+    let @mutable vec[ast.def_id] param_ids = @mutable param_ids_inner;
+    fold_ty(ty_param_counter(param_ids), t);
+    ret _vec.len[ast.def_id](*param_ids);
+}
+
+// Type accessors for AST nodes
+
 fn stmt_ty(@ast.stmt s) -> @ty {
     alt (s.node) {
         case (ast.stmt_expr(?e)) {