From 1a3bda648747e2d332f58988a12bbed1aefd4cda Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Mon, 13 Apr 2020 16:06:51 +0200 Subject: [PATCH] Miri: let push_frame hook also access and mutate the rest of the frame data --- src/librustc_mir/const_eval/machine.rs | 11 +++++--- src/librustc_mir/interpret/eval_context.rs | 31 +++++++++++++++++----- src/librustc_mir/interpret/machine.rs | 13 +++++---- src/librustc_mir/transform/const_prop.rs | 7 +++-- 4 files changed, 44 insertions(+), 18 deletions(-) diff --git a/src/librustc_mir/const_eval/machine.rs b/src/librustc_mir/const_eval/machine.rs index e92634714789..ac9ef803d3b6 100644 --- a/src/librustc_mir/const_eval/machine.rs +++ b/src/librustc_mir/const_eval/machine.rs @@ -13,8 +13,8 @@ use rustc_middle::mir::AssertMessage; use rustc_span::symbol::Symbol; use crate::interpret::{ - self, AllocId, Allocation, GlobalId, ImmTy, InterpCx, InterpResult, Memory, MemoryKind, OpTy, - PlaceTy, Pointer, Scalar, + self, AllocId, Allocation, Frame, GlobalId, ImmTy, InterpCx, InterpResult, Memory, MemoryKind, + OpTy, PlaceTy, Pointer, Scalar, }; use super::error::*; @@ -339,8 +339,11 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter { } #[inline(always)] - fn stack_push(_ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> { - Ok(()) + fn init_frame_extra( + _ecx: &mut InterpCx<'mir, 'tcx, Self>, + frame: Frame<'mir, 'tcx>, + ) -> InterpResult<'tcx, Frame<'mir, 'tcx>> { + Ok(frame) } fn before_access_global( diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs index e0b5f634bf3d..a0c6240a8a0a 100644 --- a/src/librustc_mir/interpret/eval_context.rs +++ b/src/librustc_mir/interpret/eval_context.rs @@ -159,6 +159,21 @@ impl<'tcx, Tag: Copy + 'static> LocalState<'tcx, Tag> { } } +impl<'mir, 'tcx, Tag> Frame<'mir, 'tcx, Tag> { + pub fn with_extra(self, extra: Extra) -> Frame<'mir, 'tcx, Tag, Extra> { + Frame { + body: self.body, + instance: self.instance, + return_to_block: self.return_to_block, + return_place: self.return_place, + locals: self.locals, + block: self.block, + stmt: self.stmt, + extra, + } + } +} + impl<'mir, 'tcx, Tag, Extra> Frame<'mir, 'tcx, Tag, Extra> { /// Return the `SourceInfo` of the current instruction. pub fn current_source_info(&self) -> Option { @@ -586,8 +601,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { ::log_settings::settings().indentation += 1; // first push a stack frame so we have access to the local substs - let extra = M::stack_push(self)?; - self.stack.push(Frame { + let pre_frame = Frame { body, block: Some(mir::START_BLOCK), return_to_block, @@ -597,8 +611,10 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { locals: IndexVec::new(), instance, stmt: 0, - extra, - }); + extra: (), + }; + let frame = M::init_frame_extra(self, pre_frame)?; + self.stack.push(frame); // don't allocate at all for trivial constants if body.local_decls.len() > 1 { @@ -725,11 +741,12 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { } // Cleanup: deallocate all locals that are backed by an allocation. - for local in frame.locals { + for local in &frame.locals { self.deallocate_local(local.value)?; } - if M::stack_pop(self, frame.extra, unwinding)? == StackPopJump::NoJump { + let return_place = frame.return_place; + if M::after_stack_pop(self, frame, unwinding)? == StackPopJump::NoJump { // The hook already did everything. // We want to skip the `info!` below, hence early return. return Ok(()); @@ -743,7 +760,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { // Follow the normal return edge. // Validate the return value. Do this after deallocating so that we catch dangling // references. - if let Some(return_place) = frame.return_place { + if let Some(return_place) = return_place { if M::enforce_validity(self) { // Data got changed, better make sure it matches the type! // It is still possible that the return place held invalid data while diff --git a/src/librustc_mir/interpret/machine.rs b/src/librustc_mir/interpret/machine.rs index fd67b088c93c..ffda0334a508 100644 --- a/src/librustc_mir/interpret/machine.rs +++ b/src/librustc_mir/interpret/machine.rs @@ -279,13 +279,16 @@ pub trait Machine<'mir, 'tcx>: Sized { Ok(()) } - /// Called immediately before a new stack frame got pushed. - fn stack_push(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx, Self::FrameExtra>; + /// Called immediately before a new stack frame gets pushed. + fn init_frame_extra( + ecx: &mut InterpCx<'mir, 'tcx, Self>, + frame: Frame<'mir, 'tcx, Self::PointerTag>, + ) -> InterpResult<'tcx, Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>>; - /// Called immediately after a stack frame gets popped - fn stack_pop( + /// Called immediately after a stack frame got popped, but before jumping back to the caller. + fn after_stack_pop( _ecx: &mut InterpCx<'mir, 'tcx, Self>, - _extra: Self::FrameExtra, + _frame: Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>, _unwinding: bool, ) -> InterpResult<'tcx, StackPopJump> { // By default, we do not support unwinding from panics diff --git a/src/librustc_mir/transform/const_prop.rs b/src/librustc_mir/transform/const_prop.rs index 5a00f206a764..ed5c2543ec6b 100644 --- a/src/librustc_mir/transform/const_prop.rs +++ b/src/librustc_mir/transform/const_prop.rs @@ -287,8 +287,11 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for ConstPropMachine { } #[inline(always)] - fn stack_push(_ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> { - Ok(()) + fn init_frame_extra( + _ecx: &mut InterpCx<'mir, 'tcx, Self>, + frame: Frame<'mir, 'tcx>, + ) -> InterpResult<'tcx, Frame<'mir, 'tcx>> { + Ok(frame) } }