From 29932db09bb985072dc68d9d4e4acab09e69562a Mon Sep 17 00:00:00 2001 From: woppopo Date: Wed, 26 Jan 2022 13:06:09 +0900 Subject: `const_deallocate`: Don't deallocate memory allocated in an another const. Does nothing at runtime. `const_allocate`: Returns a null pointer at runtime. --- compiler/rustc_const_eval/src/const_eval/machine.rs | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) (limited to 'compiler/rustc_const_eval/src') diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs index 62eaf333340..89717b75f12 100644 --- a/compiler/rustc_const_eval/src/const_eval/machine.rs +++ b/compiler/rustc_const_eval/src/const_eval/machine.rs @@ -358,11 +358,21 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir, Err(err) => throw_ub_format!("align has to be a power of 2, {}", err), }; - ecx.memory.deallocate( - ptr, - Some((size, align)), - interpret::MemoryKind::Machine(MemoryKind::Heap), - )?; + // If an allocation is created in an another const, + // we don't deallocate it. + let (alloc_id, _, _) = ecx.memory.ptr_get_alloc(ptr)?; + let is_allocated_in_another_const = matches!( + ecx.tcx.get_global_alloc(alloc_id), + Some(interpret::GlobalAlloc::Memory(_)) + ); + + if !is_allocated_in_another_const { + ecx.memory.deallocate( + ptr, + Some((size, align)), + interpret::MemoryKind::Machine(MemoryKind::Heap), + )?; + } } _ => { return Err(ConstEvalErrKind::NeedsRfc(format!( -- cgit 1.4.1-3-g733a5