Mark enums with non-zero discriminant as non-zero
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@ -597,7 +597,8 @@ impl<'a, 'gcx, 'tcx> Struct {
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-> Result<Option<FieldPath>, LayoutError<'gcx>> {
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let tcx = infcx.tcx.global_tcx();
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match (ty.layout(infcx)?, &ty.sty) {
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(&Scalar { non_zero: true, .. }, _) => Ok(Some(vec![])),
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(&Scalar { non_zero: true, .. }, _) |
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(&CEnum { non_zero: true, .. }, _) => Ok(Some(vec![])),
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(&FatPointer { non_zero: true, .. }, _) => {
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Ok(Some(vec![FAT_PTR_ADDR as u32]))
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}
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@ -769,6 +770,7 @@ pub enum Layout {
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CEnum {
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discr: Integer,
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signed: bool,
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non_zero: bool,
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// Inclusive discriminant range.
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// If min > max, it represents min...u64::MAX followed by 0...max.
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// FIXME(eddyb) always use the shortest range, e.g. by finding
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@ -1002,9 +1004,10 @@ impl<'a, 'gcx, 'tcx> Layout {
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if def.is_enum() && def.variants.iter().all(|v| v.fields.is_empty()) {
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// All bodies empty -> intlike
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let (mut min, mut max) = (i64::MAX, i64::MIN);
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let (mut min, mut max, mut non_zero) = (i64::MAX, i64::MIN, true);
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for v in &def.variants {
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let x = v.disr_val.to_u64_unchecked() as i64;
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if x == 0 { non_zero = false; }
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if x < min { min = x; }
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if x > max { max = x; }
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}
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@ -1013,6 +1016,7 @@ impl<'a, 'gcx, 'tcx> Layout {
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return success(CEnum {
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discr: discr,
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signed: signed,
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non_zero: non_zero,
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min: min as u64,
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max: max as u64
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});
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@ -1069,19 +1073,17 @@ impl<'a, 'gcx, 'tcx> Layout {
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// FIXME(eddyb) should take advantage of a newtype.
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if path == &[0] && variants[discr].len() == 1 {
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match *variants[discr][0].layout(infcx)? {
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Scalar { value, .. } => {
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return success(RawNullablePointer {
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nndiscr: discr as u64,
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value: value
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});
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}
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_ => {
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bug!("Layout::compute: `{}`'s non-zero \
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`{}` field not scalar?!",
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ty, variants[discr][0])
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}
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}
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let value = match *variants[discr][0].layout(infcx)? {
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Scalar { value, .. } => value,
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CEnum { discr, .. } => Int(discr),
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_ => bug!("Layout::compute: `{}`'s non-zero \
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`{}` field not scalar?!",
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ty, variants[discr][0])
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};
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return success(RawNullablePointer {
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nndiscr: discr as u64,
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value: value,
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});
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}
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path.push(0); // For GEP through a pointer.
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@ -0,0 +1,39 @@
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// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use std::mem::size_of;
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enum E {
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A = 1,
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B = 2,
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C = 3,
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}
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struct S {
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a: u16,
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b: u8,
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e: E,
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}
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fn main() {
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assert_eq!(size_of::<E>(), 1);
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assert_eq!(size_of::<Option<E>>(), 1);
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assert_eq!(size_of::<Result<E, ()>>(), 1);
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assert_eq!(size_of::<S>(), 4);
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assert_eq!(size_of::<Option<S>>(), 4);
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let enone = None::<E>;
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let esome = Some(E::A);
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if let Some(..) = enone {
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panic!();
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}
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if let None = esome {
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panic!();
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}
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}
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@ -15,6 +15,8 @@
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#![feature(test)]
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#![feature(libc)]
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#![cfg_attr(stage0, feature(question_mark))]
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#![deny(warnings)]
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extern crate libc;
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