// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.


use driver::session;
use middle::trans::base;
use middle::trans::common::{T_fn, T_i8, T_i32, T_int, T_ptr, T_void};
use lib::llvm::{ModuleRef, ValueRef, TypeRef};

pub struct Upcalls {
    trace: ValueRef,
    call_shim_on_c_stack: ValueRef,
    call_shim_on_rust_stack: ValueRef,
    rust_personality: ValueRef,
    reset_stack_limit: ValueRef
}

pub fn declare_upcalls(targ_cfg: @session::config,
                       llmod: ModuleRef) -> @Upcalls {
    fn decl(llmod: ModuleRef, prefix: ~str, name: ~str,
            tys: ~[TypeRef], rv: TypeRef) ->
       ValueRef {
        let arg_tys = tys.map(|t| *t);
        let fn_ty = T_fn(arg_tys, rv);
        return base::decl_cdecl_fn(llmod, prefix + name, fn_ty);
    }
    fn nothrow(f: ValueRef) -> ValueRef {
        base::set_no_unwind(f); f
    }
    let d: &fn(a: ~str, b: ~[TypeRef], c: TypeRef) -> ValueRef =
        |a,b,c| decl(llmod, ~"upcall_", a, b, c);
    let dv: &fn(a: ~str, b: ~[TypeRef]) -> ValueRef =
        |a,b| decl(llmod, ~"upcall_", a, b, T_void());

    let int_t = T_int(targ_cfg);

    @Upcalls {
        trace: dv(~"trace", ~[T_ptr(T_i8()),
                              T_ptr(T_i8()),
                              int_t]),
        call_shim_on_c_stack:
            d(~"call_shim_on_c_stack",
              // arguments: void *args, void *fn_ptr
              ~[T_ptr(T_i8()), T_ptr(T_i8())],
              int_t),
        call_shim_on_rust_stack:
            d(~"call_shim_on_rust_stack",
              ~[T_ptr(T_i8()), T_ptr(T_i8())], int_t),
        rust_personality:
            nothrow(d(~"rust_personality", ~[], T_i32())),
        reset_stack_limit:
            nothrow(dv(~"reset_stack_limit", ~[]))
    }
}