Add a morestack_addr (temporary) intrinsic

Author: brson

src/rustc/middle/trans/foreign.rs

@@ -993,6 +993,16 @@ fn trans_intrinsic(ccx: @crate_ctxt, decl: ValueRef, item: @ast::foreign_item,
                                    lv_temporary),
                                arg_vals(~[frameaddress_val]), ignore);
       }
+      ~"morestack_addr" => {
+        // XXX This is a hack to grab the address of this particular
+        // native function. There should be a general in-language
+        // way to do this
+        let llfty = type_of_fn(bcx.ccx(), ~[], ty::mk_nil(bcx.tcx()));
+        let morestack_addr = decl_cdecl_fn(
+            bcx.ccx().llmod, ~"__morestack", llfty);
+        let morestack_addr = PointerCast(bcx, morestack_addr, T_ptr(T_nil()));
+        Store(bcx, morestack_addr, fcx.llretptr);
+      }
       _ => {
       // Could we make this an enum rather than a string? does it get
       // checked earlier?

src/rustc/middle/typeck/check.rs

@@ -2590,6 +2590,9 @@ fn check_intrinsic_type(ccx: @crate_ctxt, it: @ast::foreign_item) {
         });
         (0u, ~[arg(ast::by_ref, fty)], ty::mk_nil(tcx))
       }
+      ~"morestack_addr" => {
+        (0u, ~[], ty::mk_nil_ptr(tcx))
+      }
       other => {
         tcx.sess.span_err(it.span, ~"unrecognized intrinsic function: `" +
                           other + ~"`");

src/test/run-pass/morestack-address.rs

@@ -0,0 +1,11 @@
+#[nolink]
+#[abi = "rust-intrinsic"]
+extern mod rusti {
+    fn morestack_addr() -> *();
+}
+
+fn main() {
+    let addr = rusti::morestack_addr();
+    assert addr.is_not_null();
+    error!("%?", addr);
+}