diff options
| -rw-r--r-- | src/librustc_mir/transform/const_prop.rs | 123 |
1 files changed, 52 insertions, 71 deletions
diff --git a/src/librustc_mir/transform/const_prop.rs b/src/librustc_mir/transform/const_prop.rs index 45cbdc7d0c1..fc2a149cfe9 100644 --- a/src/librustc_mir/transform/const_prop.rs +++ b/src/librustc_mir/transform/const_prop.rs @@ -359,81 +359,62 @@ impl<'b, 'a, 'tcx> Visitor<'tcx> for ConstPropagator<'b, 'a, 'tcx> { &mut self, block: BasicBlock, kind: &TerminatorKind<'tcx>, - _location: Location, + location: Location, ) { - match kind { - TerminatorKind::SwitchInt { discr: value, .. } | - TerminatorKind::Yield { value, .. } | - TerminatorKind::Assert { cond: value, .. } => { - match value { - Operand::Constant(box Constant { - literal: Literal::Value { - value: &ty::Const { - val: ConstVal::Value(_), - .. - }, - }, - .. - }) => return, - _ => {}, - } - if let Some(value) = self.eval_operand(value) { - if let TerminatorKind::Assert { expected, msg, .. } = kind { - if Value::ByVal(PrimVal::from_bool(*expected)) != value.0 { - let span = self.mir[block] - .terminator - .as_ref() - .unwrap() - .source_info - .span; - let node_id = self - .tcx - .hir - .as_local_node_id(self.source.def_id) - .expect("some part of a failing const eval must be local"); - let mut lint = self.tcx.struct_span_lint_node( - ::rustc::lint::builtin::CONST_ERR, - node_id, + self.super_terminator_kind(block, kind, location); + if let TerminatorKind::Assert { expected, msg, cond, .. } = kind { + if let Some(value) = self.eval_operand(cond) { + if Value::ByVal(PrimVal::from_bool(*expected)) != value.0 { + let span = self.mir[block] + .terminator + .as_ref() + .unwrap() + .source_info + .span; + let node_id = self + .tcx + .hir + .as_local_node_id(self.source.def_id) + .expect("some part of a failing const eval must be local"); + let mut lint = self.tcx.struct_span_lint_node( + ::rustc::lint::builtin::CONST_ERR, + node_id, + span, + "constant evaluation error", + ); + use rustc::mir::AssertMessage::*; + match msg { + GeneratorResumedAfterReturn => + lint.span_label(span, "generator resumed after completion"), + GeneratorResumedAfterPanic => + lint.span_label(span, "generator resumed after panicking"), + Math(ref err) => lint.span_label(span, err.description()), + BoundsCheck { ref len, ref index } => { + let len = self.eval_operand(len).expect("len must be const"); + let len = match len.0 { + Value::ByVal(PrimVal::Bytes(n)) => n, + _ => bug!("const len not primitive: {:?}", len), + }; + let index = self + .eval_operand(index) + .expect("index must be const"); + let index = match index.0 { + Value::ByVal(PrimVal::Bytes(n)) => n, + _ => bug!("const index not primitive: {:?}", index), + }; + lint.span_label( span, - "constant evaluation error", - ); - use rustc::mir::AssertMessage::*; - match msg { - GeneratorResumedAfterReturn => - lint.span_label(span, "generator resumed after completion"), - GeneratorResumedAfterPanic => - lint.span_label(span, "generator resumed after panicking"), - Math(ref err) => lint.span_label(span, err.description()), - BoundsCheck { ref len, ref index } => { - let len = self.eval_operand(len).expect("len must be const"); - let len = match len.0 { - Value::ByVal(PrimVal::Bytes(n)) => n, - _ => bug!("const len not primitive: {:?}", len), - }; - let index = self - .eval_operand(index) - .expect("index must be const"); - let index = match index.0 { - Value::ByVal(PrimVal::Bytes(n)) => n, - _ => bug!("const index not primitive: {:?}", index), - }; - lint.span_label( - span, - format!( - "index out of bounds: \ - the len is {} but the index is {}", - len, - index, - ), - ) - }, - }.emit(); - } - } + format!( + "index out of bounds: \ + the len is {} but the index is {}", + len, + index, + ), + ) + }, + }.emit(); } } - // FIXME: do this optimization for function calls - _ => {}, } } } |