diff options
| -rw-r--r-- | src/librustc_trans/glue.rs | 13 | ||||
| -rw-r--r-- | src/test/run-pass/issue-36278-prefix-nesting.rs | 28 |
2 files changed, 40 insertions, 1 deletions
diff --git a/src/librustc_trans/glue.rs b/src/librustc_trans/glue.rs index 34c92f334d0..967ecd9ba41 100644 --- a/src/librustc_trans/glue.rs +++ b/src/librustc_trans/glue.rs @@ -348,9 +348,20 @@ pub fn size_and_align_of_dst<'blk, 'tcx>(bcx: &BlockAndBuilder<'blk, 'tcx>, let layout = ccx.layout_of(t); debug!("DST {} layout: {:?}", t, layout); + // Returns size in bytes of all fields except the last one + // (we will be recursing on the last one). + fn local_prefix_bytes(variant: &ty::layout::Struct) -> u64 { + let fields = variant.offset_after_field.len(); + if fields > 1 { + variant.offset_after_field[fields - 2].bytes() + } else { + 0 + } + } + let (sized_size, sized_align) = match *layout { ty::layout::Layout::Univariant { ref variant, .. } => { - (variant.min_size().bytes(), variant.align.abi()) + (local_prefix_bytes(variant), variant.align.abi()) } _ => { bug!("size_and_align_of_dst: expcted Univariant for `{}`, found {:#?}", diff --git a/src/test/run-pass/issue-36278-prefix-nesting.rs b/src/test/run-pass/issue-36278-prefix-nesting.rs new file mode 100644 index 00000000000..95269d0569d --- /dev/null +++ b/src/test/run-pass/issue-36278-prefix-nesting.rs @@ -0,0 +1,28 @@ +// Copyright 2016 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. + +// Issue 36278: On an unsized struct with >1 level of nontrivial +// nesting, ensure we are computing dynamic size of prefix correctly. + +use std::mem; + +const SZ: usize = 100; +struct P<T: ?Sized>([u8; SZ], T); + +type Ack<T> = P<P<T>>; + +fn main() { + let size_of_sized; let size_of_unsized; + let x: Box<Ack<[u8; 0]>> = Box::new(P([0; SZ], P([0; SZ], [0; 0]))); + size_of_sized = mem::size_of_val::<Ack<_>>(&x); + let y: Box<Ack<[u8 ]>> = x; + size_of_unsized = mem::size_of_val::<Ack<_>>(&y); + assert_eq!(size_of_sized, size_of_unsized); +} |