WIP: Replace all memory allocations with fallible allocations and swap the… #29
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… global allocator in runtests.rs with the tests' own
ahomescu
changed the title
| @@ -13,6 +13,8 @@ | |||
| #![feature(main)] | |||
| #![feature(const_in_array_repeat_expressions)] | |||
| #![feature(ptr_wrapping_offset_from)] | |||
| #![feature(try_reserve)] | |||
| #![feature(alloc_layout_extra)] | |||
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Don't we want to not add nightly features?
If we do add them, be sure to update #18
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Reading rust-lang/rust#55724 (comment) makes me think they'll stabilize more of Layout soon. There's also been some recent discussion on stabilizing try_reserve.
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One alternative Stephen and I were discussing earlier is to have a nightly or fallible feature that conditionally enables fallible allocation, and fall back to panics if building for stable Rust. We really, really need the nightly features for runtests, but could allow panics outside of that.
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I just realized something else: alloc_layout_extra is temporary, since once we replace all pointers with slices/boxes/etc we won't need to manually allocate any memory, so that feature will go away. We'll still need try_reserve, but we can enable that conditionally.
src/lib/xmlparse.rs
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| if let XML_ParserStruct {ref m_mem, ref mut m_tempPool, ref mut m_temp2Pool, ..} = &mut *parser { | ||
| m_tempPool.init(m_mem); | ||
| m_temp2Pool.init(m_mem); | ||
| if let XML_ParserStruct {ref mut m_tempPool, ref mut m_temp2Pool, ..} = &mut *parser { |
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You should be able to remove this if let binding now. I added it so that the m_tempPool field could be used mutably along with m_mem being used immutably in the same line
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Btw, to avoid a compiler warning about the irrefutable if-let pattern, that let binding could have been:
{
let XML_ParserStruct {ref mut m_tempPool, ref mut m_temp2Pool, ..} = &mut *parser;
// do stuff..
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That whole conditional is gone now, but the point about the let binding is good to know.
…locating m_dataBuf
| .expect("non-null function pointer")($ptr) | ||
| ($ptr:expr $(,)?) => { | ||
| // FIXME: get the actual layout somehow | ||
| alloc::dealloc($ptr as *mut u8, Layout::new::<u8>()) |
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What happens if someone swaps the global allocator on us between allocation and freeing?
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Bad things happen. I don't have a good way of handling that case, and I don't think Rust does either. The global allocator is supposed to be a singleton.
… global allocator in runtests.rs with the tests' own