From f1023fbdc9aafc8c78c7a6967d0dc4daa741c2a1 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Mon, 18 Apr 2022 12:38:26 -0400 Subject: [PATCH] avoid into_pointer_or_addr and into_parts in visit_freeze_sensitive --- src/helpers.rs | 34 ++++++++++++++-------------------- src/intptrcast.rs | 4 ++-- src/machine.rs | 1 + src/shims/mod.rs | 5 ++--- 4 files changed, 19 insertions(+), 25 deletions(-) diff --git a/src/helpers.rs b/src/helpers.rs index b052463bb02..9d387b06593 100644 --- a/src/helpers.rs +++ b/src/helpers.rs @@ -271,8 +271,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx /// Visits the memory covered by `place`, sensitive to freezing: the 2nd parameter /// of `action` will be true if this is frozen, false if this is in an `UnsafeCell`. /// The range is relative to `place`. - /// - /// Assumes that the `place` has a proper pointer in it. fn visit_freeze_sensitive( &self, place: &MPlaceTy<'tcx, Tag>, @@ -290,33 +288,30 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx // Store how far we proceeded into the place so far. Everything to the left of // this offset has already been handled, in the sense that the frozen parts // have had `action` called on them. - let ptr = place.ptr.into_pointer_or_addr().unwrap(); - let start_offset = ptr.into_parts().1 as Size; // we just compare offsets, the abs. value never matters - let mut cur_offset = start_offset; + let start_addr = place.ptr.addr(); + let mut cur_addr = start_addr; // Called when we detected an `UnsafeCell` at the given offset and size. // Calls `action` and advances `cur_ptr`. - let mut unsafe_cell_action = |unsafe_cell_ptr: Pointer>, + let mut unsafe_cell_action = |unsafe_cell_ptr: &Pointer>, unsafe_cell_size: Size| { - let unsafe_cell_ptr = unsafe_cell_ptr.into_pointer_or_addr().unwrap(); - debug_assert_eq!(unsafe_cell_ptr.provenance, ptr.provenance); // We assume that we are given the fields in increasing offset order, // and nothing else changes. - let unsafe_cell_offset = unsafe_cell_ptr.into_parts().1 as Size; // we just compare offsets, the abs. value never matters - assert!(unsafe_cell_offset >= cur_offset); - let frozen_size = unsafe_cell_offset - cur_offset; + let unsafe_cell_addr = unsafe_cell_ptr.addr(); + assert!(unsafe_cell_addr >= cur_addr); + let frozen_size = unsafe_cell_addr - cur_addr; // Everything between the cur_ptr and this `UnsafeCell` is frozen. if frozen_size != Size::ZERO { - action(alloc_range(cur_offset - start_offset, frozen_size), /*frozen*/ true)?; + action(alloc_range(cur_addr - start_addr, frozen_size), /*frozen*/ true)?; } - cur_offset += frozen_size; + cur_addr += frozen_size; // This `UnsafeCell` is NOT frozen. if unsafe_cell_size != Size::ZERO { action( - alloc_range(cur_offset - start_offset, unsafe_cell_size), + alloc_range(cur_addr - start_addr, unsafe_cell_size), /*frozen*/ false, )?; } - cur_offset += unsafe_cell_size; + cur_addr += unsafe_cell_size; // Done Ok(()) }; @@ -334,7 +329,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx .unwrap_or_else(|| place.layout.size); // Now handle this `UnsafeCell`, unless it is empty. if unsafe_cell_size != Size::ZERO { - unsafe_cell_action(place.ptr, unsafe_cell_size) + unsafe_cell_action(&place.ptr, unsafe_cell_size) } else { Ok(()) } @@ -344,7 +339,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx } // The part between the end_ptr and the end of the place is also frozen. // So pretend there is a 0-sized `UnsafeCell` at the end. - unsafe_cell_action(place.ptr.wrapping_offset(size, this), Size::ZERO)?; + unsafe_cell_action(&place.ptr.offset(size, this)?, Size::ZERO)?; // Done! return Ok(()); @@ -428,9 +423,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx let mut places = fields.collect::>>>()?; // we just compare offsets, the abs. value never matters - places.sort_by_key(|place| { - place.ptr.into_pointer_or_addr().unwrap().into_parts().1 as Size - }); + places.sort_by_key(|place| place.ptr.addr()); self.walk_aggregate(place, places.into_iter().map(Ok)) } FieldsShape::Union { .. } | FieldsShape::Primitive => { @@ -777,6 +770,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx /// Mark a machine allocation that was just created as immutable. fn mark_immutable(&mut self, mplace: &MemPlace) { let this = self.eval_context_mut(); + // This got just allocated, so there definitely is a pointer here. this.alloc_mark_immutable(mplace.ptr.into_pointer_or_addr().unwrap().provenance.alloc_id) .unwrap(); } diff --git a/src/intptrcast.rs b/src/intptrcast.rs index b1c96c7f1e7..895241bcc32 100644 --- a/src/intptrcast.rs +++ b/src/intptrcast.rs @@ -128,7 +128,7 @@ impl<'mir, 'tcx> GlobalStateInner { /// Convert a relative (tcx) pointer to an absolute address. pub fn rel_ptr_to_addr(ecx: &MiriEvalContext<'mir, 'tcx>, ptr: Pointer) -> u64 { - let (alloc_id, offset) = ptr.into_parts(); // offset is relative + let (alloc_id, offset) = ptr.into_parts(); // offset is relative (AllocId provenance) let base_addr = GlobalStateInner::alloc_base_addr(ecx, alloc_id); // Add offset with the right kind of pointer-overflowing arithmetic. @@ -137,7 +137,7 @@ impl<'mir, 'tcx> GlobalStateInner { } pub fn abs_ptr_to_rel(ecx: &MiriEvalContext<'mir, 'tcx>, ptr: Pointer) -> Size { - let (tag, addr) = ptr.into_parts(); // addr is absolute + let (tag, addr) = ptr.into_parts(); // addr is absolute (Tag provenance) let base_addr = GlobalStateInner::alloc_base_addr(ecx, tag.alloc_id); // Wrapping "addr - base_addr" diff --git a/src/machine.rs b/src/machine.rs index df53d90b05c..66854921a33 100644 --- a/src/machine.rs +++ b/src/machine.rs @@ -360,6 +360,7 @@ impl<'mir, 'tcx> Evaluator<'mir, 'tcx> { name: &str, ptr: Pointer>, ) { + // This got just allocated, so there definitely is a pointer here. let ptr = ptr.into_pointer_or_addr().unwrap(); this.machine.extern_statics.try_insert(Symbol::intern(name), ptr).unwrap(); } diff --git a/src/shims/mod.rs b/src/shims/mod.rs index 83bc6b6ae1b..af6064925f0 100644 --- a/src/shims/mod.rs +++ b/src/shims/mod.rs @@ -83,10 +83,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx } let ptr = this.read_pointer(ptr_op)?; - if let Ok(ptr) = ptr.into_pointer_or_addr() { + if let Ok((alloc_id, _offset, _)) = this.ptr_try_get_alloc_id(ptr) { // Only do anything if we can identify the allocation this goes to. - let (_, cur_align) = - this.get_alloc_size_and_align(ptr.provenance.alloc_id, AllocCheck::MaybeDead)?; + let (_, cur_align) = this.get_alloc_size_and_align(alloc_id, AllocCheck::MaybeDead)?; if cur_align.bytes() >= req_align { // If the allocation alignment is at least the required alignment we use the // real implementation.