diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs index 30e9cbe44035..62eaf3333404 100644 --- a/compiler/rustc_const_eval/src/const_eval/machine.rs +++ b/compiler/rustc_const_eval/src/const_eval/machine.rs @@ -347,6 +347,23 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir, )?; ecx.write_pointer(ptr, dest)?; } + sym::const_deallocate => { + let ptr = ecx.read_pointer(&args[0])?; + let size = ecx.read_scalar(&args[1])?.to_machine_usize(ecx)?; + let align = ecx.read_scalar(&args[2])?.to_machine_usize(ecx)?; + + let size = Size::from_bytes(size); + let align = match Align::from_bytes(align) { + Ok(a) => a, + 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), + )?; + } _ => { return Err(ConstEvalErrKind::NeedsRfc(format!( "calling intrinsic `{}`", diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index 9870c90f2ec9..c87bb1d57471 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -460,6 +460,7 @@ symbols! { const_async_blocks, const_compare_raw_pointers, const_constructor, + const_deallocate, const_eval_limit, const_eval_select, const_eval_select_ct, diff --git a/compiler/rustc_typeck/src/check/intrinsic.rs b/compiler/rustc_typeck/src/check/intrinsic.rs index 4c612ed5be51..74f6f50d4128 100644 --- a/compiler/rustc_typeck/src/check/intrinsic.rs +++ b/compiler/rustc_typeck/src/check/intrinsic.rs @@ -297,6 +297,11 @@ pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) { sym::const_allocate => { (0, vec![tcx.types.usize, tcx.types.usize], tcx.mk_mut_ptr(tcx.types.u8)) } + sym::const_deallocate => ( + 0, + vec![tcx.mk_mut_ptr(tcx.types.u8), tcx.types.usize, tcx.types.usize], + tcx.mk_unit(), + ), sym::ptr_offset_from => { (1, vec![tcx.mk_imm_ptr(param(0)), tcx.mk_imm_ptr(param(0))], tcx.types.isize) diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs index 9781dc320edd..10b5e06fc505 100644 --- a/library/core/src/intrinsics.rs +++ b/library/core/src/intrinsics.rs @@ -1918,6 +1918,12 @@ extern "rust-intrinsic" { #[rustc_const_unstable(feature = "const_heap", issue = "79597")] pub fn const_allocate(size: usize, align: usize) -> *mut u8; + /// Deallocate a memory which allocated by `intrinsics::const_allocate` at compile time. + /// Should not be called at runtime. + #[rustc_const_unstable(feature = "const_heap", issue = "79597")] + #[cfg(not(bootstrap))] + pub fn const_deallocate(ptr: *mut u8, size: usize, align: usize); + /// Determines whether the raw bytes of the two values are equal. /// /// This is particularly handy for arrays, since it allows things like just diff --git a/src/test/ui/consts/const-eval/heap/dealloc_intrinsic.rs b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic.rs new file mode 100644 index 000000000000..b7c2b7526442 --- /dev/null +++ b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic.rs @@ -0,0 +1,12 @@ +// run-pass +#![feature(core_intrinsics)] +#![feature(const_heap)] + +use std::intrinsics; + +const _X: () = unsafe { + let ptr = intrinsics::const_allocate(4, 4); + intrinsics::const_deallocate(ptr, 4, 4); +}; + +fn main() {} diff --git a/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_dangling.rs b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_dangling.rs new file mode 100644 index 000000000000..b6d89a58dce7 --- /dev/null +++ b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_dangling.rs @@ -0,0 +1,22 @@ +#![feature(core_intrinsics)] +#![feature(const_heap)] +#![feature(const_mut_refs)] + +use std::intrinsics; + +const _X: &'static u8 = unsafe { + let ptr = intrinsics::const_allocate(4, 4); + intrinsics::const_deallocate(ptr, 4, 4); + &*ptr + //~^ error: evaluation of constant value failed +}; + +const _Y: u8 = unsafe { + let ptr = intrinsics::const_allocate(4, 4); + let reference = &*ptr; + intrinsics::const_deallocate(ptr, 4, 4); + *reference + //~^ error: evaluation of constant value failed +}; + +fn main() {} diff --git a/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_dangling.stderr b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_dangling.stderr new file mode 100644 index 000000000000..4eb1c42e1f76 --- /dev/null +++ b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_dangling.stderr @@ -0,0 +1,15 @@ +error[E0080]: evaluation of constant value failed + --> $DIR/dealloc_intrinsic_dangling.rs:10:5 + | +LL | &*ptr + | ^^^^^ pointer to alloc2 was dereferenced after this allocation got freed + +error[E0080]: evaluation of constant value failed + --> $DIR/dealloc_intrinsic_dangling.rs:18:5 + | +LL | *reference + | ^^^^^^^^^^ pointer to alloc4 was dereferenced after this allocation got freed + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0080`. diff --git a/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_duplicate.rs b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_duplicate.rs new file mode 100644 index 000000000000..4010b476990d --- /dev/null +++ b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_duplicate.rs @@ -0,0 +1,13 @@ +#![feature(core_intrinsics)] +#![feature(const_heap)] + +use std::intrinsics; + +const _X: () = unsafe { + let ptr = intrinsics::const_allocate(4, 4); + intrinsics::const_deallocate(ptr, 4, 4); + intrinsics::const_deallocate(ptr, 4, 4); + //~^ error: evaluation of constant value failed +}; + +fn main() {} diff --git a/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_duplicate.stderr b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_duplicate.stderr new file mode 100644 index 000000000000..8177a08504b0 --- /dev/null +++ b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_duplicate.stderr @@ -0,0 +1,9 @@ +error[E0080]: evaluation of constant value failed + --> $DIR/dealloc_intrinsic_duplicate.rs:9:5 + | +LL | intrinsics::const_deallocate(ptr, 4, 4); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pointer to alloc2 was dereferenced after this allocation got freed + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0080`. diff --git a/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_incorrect_layout.rs b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_incorrect_layout.rs new file mode 100644 index 000000000000..031d70fdc889 --- /dev/null +++ b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_incorrect_layout.rs @@ -0,0 +1,29 @@ +#![feature(core_intrinsics)] +#![feature(const_heap)] + +use std::intrinsics; + +const _X: () = unsafe { + let ptr = intrinsics::const_allocate(4, 4); + intrinsics::const_deallocate(ptr, 4, 2); + //~^ error: evaluation of constant value failed +}; +const _Y: () = unsafe { + let ptr = intrinsics::const_allocate(4, 4); + intrinsics::const_deallocate(ptr, 2, 4); + //~^ error: evaluation of constant value failed +}; + +const _Z: () = unsafe { + let ptr = intrinsics::const_allocate(4, 4); + intrinsics::const_deallocate(ptr, 3, 4); + //~^ error: evaluation of constant value failed +}; + +const _W: () = unsafe { + let ptr = intrinsics::const_allocate(4, 4); + intrinsics::const_deallocate(ptr, 4, 3); + //~^ error: evaluation of constant value failed +}; + +fn main() {} diff --git a/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_incorrect_layout.stderr b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_incorrect_layout.stderr new file mode 100644 index 000000000000..650b409b1908 --- /dev/null +++ b/src/test/ui/consts/const-eval/heap/dealloc_intrinsic_incorrect_layout.stderr @@ -0,0 +1,27 @@ +error[E0080]: evaluation of constant value failed + --> $DIR/dealloc_intrinsic_incorrect_layout.rs:8:5 + | +LL | intrinsics::const_deallocate(ptr, 4, 2); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ incorrect layout on deallocation: alloc2 has size 4 and alignment 4, but gave size 4 and alignment 2 + +error[E0080]: evaluation of constant value failed + --> $DIR/dealloc_intrinsic_incorrect_layout.rs:13:5 + | +LL | intrinsics::const_deallocate(ptr, 2, 4); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ incorrect layout on deallocation: alloc4 has size 4 and alignment 4, but gave size 2 and alignment 4 + +error[E0080]: evaluation of constant value failed + --> $DIR/dealloc_intrinsic_incorrect_layout.rs:19:5 + | +LL | intrinsics::const_deallocate(ptr, 3, 4); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ incorrect layout on deallocation: alloc6 has size 4 and alignment 4, but gave size 3 and alignment 4 + +error[E0080]: evaluation of constant value failed + --> $DIR/dealloc_intrinsic_incorrect_layout.rs:25:5 + | +LL | intrinsics::const_deallocate(ptr, 4, 3); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ align has to be a power of 2, `3` is not a power of 2 + +error: aborting due to 4 previous errors + +For more information about this error, try `rustc --explain E0080`.