rust/src/librustc_mir/build/misc.rs

// Copyright 2015 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.

//! Miscellaneous builder routines that are not specific to building any particular
//! kind of thing.

use build::Builder;
use rustc::ty::Ty;
use rustc::mir::repr::*;
use std::u32;
use syntax::codemap::Span;

impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
    /// Add a new temporary value of type `ty` storing the result of
    /// evaluating `expr`.
    ///
    /// NB: **No cleanup is scheduled for this temporary.** You should
    /// call `schedule_drop` once the temporary is initialized.
    pub fn temp(&mut self, ty: Ty<'tcx>) -> Lvalue<'tcx> {
        let index = self.temp_decls.len();
        self.temp_decls.push(TempDecl { ty: ty });
        assert!(index < (u32::MAX) as usize);
        let lvalue = Lvalue::Temp(index as u32);
        debug!("temp: created temp {:?} with type {:?}",
               lvalue, self.temp_decls.last().unwrap().ty);
        lvalue
    }

    pub fn literal_operand(&mut self,
                           span: Span,
                           ty: Ty<'tcx>,
                           literal: Literal<'tcx>)
                           -> Operand<'tcx> {
        let constant = Constant {
            span: span,
            ty: ty,
            literal: literal,
        };
        Operand::Constant(constant)
    }

    pub fn unit_rvalue(&mut self) -> Rvalue<'tcx> {
        Rvalue::Aggregate(AggregateKind::Tuple, vec![])
    }

    pub fn push_usize(&mut self,
                      block: BasicBlock,
                      scope_id: ScopeId,
                      span: Span,
                      value: u64)
                      -> Lvalue<'tcx> {
        let usize_ty = self.hir.usize_ty();
        let temp = self.temp(usize_ty);
        self.cfg.push_assign_constant(
            block, scope_id, span, &temp,
            Constant {
                span: span,
                ty: self.hir.usize_ty(),
                literal: self.hir.usize_literal(value),
            });
        temp
    }
}