diff options
| -rw-r--r-- | src/librustc_mir/interpret/eval_context.rs | 36 |
1 files changed, 14 insertions, 22 deletions
diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs index 376c7f24058..10d509548d9 100644 --- a/src/librustc_mir/interpret/eval_context.rs +++ b/src/librustc_mir/interpret/eval_context.rs @@ -9,7 +9,7 @@ use rustc::ty::layout::{self, Size, Align, HasDataLayout, LayoutOf, TyLayout}; use rustc::ty::subst::{Subst, Substs}; use rustc::ty::{self, Ty, TyCtxt}; use rustc::ty::maps::TyCtxtAt; -use rustc_data_structures::indexed_vec::Idx; +use rustc_data_structures::indexed_vec::{IndexVec, Idx}; use rustc::middle::const_val::FrameInfo; use syntax::codemap::{self, Span}; use syntax::ast::Mutability; @@ -71,12 +71,12 @@ pub struct Frame<'mir, 'tcx: 'mir> { pub return_place: Place, /// The list of locals for this stack frame, stored in order as - /// `[arguments..., variables..., temporaries...]`. The locals are stored as `Option<Value>`s. + /// `[return_ptr, arguments..., variables..., temporaries...]`. The locals are stored as `Option<Value>`s. /// `None` represents a local that is currently dead, while a live local /// can either directly contain `PrimVal` or refer to some part of an `Allocation`. /// /// Before being initialized, arguments are `Value::ByVal(PrimVal::Undef)` and other locals are `None`. - pub locals: Vec<Option<Value>>, + pub locals: IndexVec<mir::Local, Option<Value>>, //////////////////////////////////////////////////////////////////////////////// // Current position within the function @@ -383,11 +383,7 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M ) -> EvalResult<'tcx> { ::log_settings::settings().indentation += 1; - // Subtract 1 because `local_decls` includes the ReturnMemoryPointer, but we don't store a local - // `Value` for that. - let num_locals = mir.local_decls.len() - 1; - - let mut locals = vec![Some(Value::ByVal(PrimVal::Undef)); num_locals]; + let mut locals = IndexVec::from_elem(Some(Value::ByVal(PrimVal::Undef)), &mir.local_decls); match self.tcx.describe_def(instance.def_id()) { // statics and constants don't have `Storage*` statements, no need to look for them Some(Def::Static(..)) | Some(Def::Const(..)) | Some(Def::AssociatedConst(..)) => {}, @@ -397,9 +393,8 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M for stmt in block.statements.iter() { use rustc::mir::StatementKind::{StorageDead, StorageLive}; match stmt.kind { - StorageLive(local) | StorageDead(local) => if local.index() > 0 { - locals[local.index() - 1] = None; - }, + StorageLive(local) | + StorageDead(local) => locals[local] = None, _ => {} } } @@ -962,8 +957,7 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M pub fn force_allocation(&mut self, place: Place) -> EvalResult<'tcx, Place> { let new_place = match place { Place::Local { frame, local } => { - // -1 since we don't store the return value - match self.stack[frame].locals[local.index() - 1] { + match self.stack[frame].locals[local] { None => return err!(DeadLocal), Some(Value::ByRef(ptr, align)) => { Place::Ptr { @@ -977,7 +971,7 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M let ty = self.monomorphize(ty, self.stack[frame].instance.substs); let layout = self.layout_of(ty)?; let ptr = self.alloc_ptr(ty)?; - self.stack[frame].locals[local.index() - 1] = + self.stack[frame].locals[local] = Some(Value::ByRef(ptr.into(), layout.align)); // it stays live let place = Place::from_ptr(ptr, layout.align); self.write_value(ValTy { value: val, ty }, place)?; @@ -1691,13 +1685,11 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M impl<'mir, 'tcx> Frame<'mir, 'tcx> { pub fn get_local(&self, local: mir::Local) -> EvalResult<'tcx, Value> { - // Subtract 1 because we don't store a value for the ReturnPointer, the local with index 0. - self.locals[local.index() - 1].ok_or(EvalErrorKind::DeadLocal.into()) + self.locals[local].ok_or(EvalErrorKind::DeadLocal.into()) } fn set_local(&mut self, local: mir::Local, value: Value) -> EvalResult<'tcx> { - // Subtract 1 because we don't store a value for the ReturnPointer, the local with index 0. - match self.locals[local.index() - 1] { + match self.locals[local] { None => err!(DeadLocal), Some(ref mut local) => { *local = value; @@ -1709,8 +1701,8 @@ impl<'mir, 'tcx> Frame<'mir, 'tcx> { pub fn storage_live(&mut self, local: mir::Local) -> EvalResult<'tcx, Option<Value>> { trace!("{:?} is now live", local); - let old = self.locals[local.index() - 1]; - self.locals[local.index() - 1] = Some(Value::ByVal(PrimVal::Undef)); // StorageLive *always* kills the value that's currently stored + let old = self.locals[local]; + self.locals[local] = Some(Value::ByVal(PrimVal::Undef)); // StorageLive *always* kills the value that's currently stored return Ok(old); } @@ -1718,8 +1710,8 @@ impl<'mir, 'tcx> Frame<'mir, 'tcx> { pub fn storage_dead(&mut self, local: mir::Local) -> EvalResult<'tcx, Option<Value>> { trace!("{:?} is now dead", local); - let old = self.locals[local.index() - 1]; - self.locals[local.index() - 1] = None; + let old = self.locals[local]; + self.locals[local] = None; return Ok(old); } } |