rust/src/librustc_trans/trans/basic_block.rs
2014-12-13 17:03:44 -05:00

56 lines
1.6 KiB
Rust

// Copyright 2013 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 llvm;
use llvm::{BasicBlockRef};
use trans::value::{Users, Value};
use std::iter::{Filter, Map};
pub struct BasicBlock(pub BasicBlockRef);
impl Copy for BasicBlock {}
pub type Preds = Map<
Value,
BasicBlock,
Filter<Value, Users, fn(&Value) -> bool>,
fn(Value) -> BasicBlock,
>;
/// Wrapper for LLVM BasicBlockRef
impl BasicBlock {
pub fn get(&self) -> BasicBlockRef {
let BasicBlock(v) = *self; v
}
pub fn as_value(self) -> Value {
unsafe {
Value(llvm::LLVMBasicBlockAsValue(self.get()))
}
}
pub fn pred_iter(self) -> Preds {
fn is_a_terminator_inst(user: &Value) -> bool { user.is_a_terminator_inst() }
fn get_parent(user: Value) -> BasicBlock { user.get_parent().unwrap() }
self.as_value().user_iter()
.filter(is_a_terminator_inst)
.map(get_parent)
}
pub fn get_single_predecessor(self) -> Option<BasicBlock> {
let mut iter = self.pred_iter();
match (iter.next(), iter.next()) {
(Some(first), None) => Some(first),
_ => None
}
}
}