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Auto merge of #51727 - varkor:expragain-to-exprcontinue, r=petrochenkov
Rename hir::ExprAgain to hir::ExprContinue The current name is confusing and historical. I also used this PR to clean up the annoying indentation in `check/mod.rs`. If that's viewed as too tangential a change, I'll split it up, but it seemed reasonable to slip it in to reduce @bors's work. It's easy to compare for the two commits individually. r? @petrochenkov
This commit is contained in:
bors
@@ -335,7 +335,7 @@ fn expr(&mut self, expr: &hir::Expr, pred: CFGIndex) -> CFGIndex {
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self.add_unreachable_node()
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}
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hir::ExprAgain(destination) => {
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hir::ExprContinue(destination) => {
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let (target_scope, cont_dest) =
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self.find_scope_edge(expr, destination, ScopeCfKind::Continue);
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let a = self.add_ast_node(expr.hir_id.local_id, &[pred]);
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@@ -1068,7 +1068,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
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}
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walk_list!(visitor, visit_expr, opt_expr);
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}
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ExprAgain(ref destination) => {
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ExprContinue(ref destination) => {
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if let Some(ref label) = destination.label {
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visitor.visit_label(label);
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match destination.target_id {
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@@ -3731,7 +3731,7 @@ fn lower_expr(&mut self, e: &Expr) -> hir::Expr {
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)
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}
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ExprKind::Continue(opt_label) => {
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hir::ExprAgain(if self.is_in_loop_condition && opt_label.is_none() {
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hir::ExprContinue(if self.is_in_loop_condition && opt_label.is_none() {
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hir::Destination {
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label: None,
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target_id: Err(hir::LoopIdError::UnlabeledCfInWhileCondition).into(),
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@@ -1279,7 +1279,7 @@ pub fn precedence(&self) -> ExprPrecedence {
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ExprPath(..) => ExprPrecedence::Path,
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ExprAddrOf(..) => ExprPrecedence::AddrOf,
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ExprBreak(..) => ExprPrecedence::Break,
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ExprAgain(..) => ExprPrecedence::Continue,
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ExprContinue(..) => ExprPrecedence::Continue,
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ExprRet(..) => ExprPrecedence::Ret,
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ExprInlineAsm(..) => ExprPrecedence::InlineAsm,
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ExprStruct(..) => ExprPrecedence::Struct,
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@@ -1374,7 +1374,7 @@ pub enum Expr_ {
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/// A `break`, with an optional label to break
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ExprBreak(Destination, Option<P<Expr>>),
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/// A `continue`, with an optional label
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ExprAgain(Destination),
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ExprContinue(Destination),
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/// A `return`, with an optional value to be returned
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ExprRet(Option<P<Expr>>),
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@@ -1475,7 +1475,7 @@ pub fn print_expr(&mut self, expr: &hir::Expr) -> io::Result<()> {
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self.s.space()?;
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}
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}
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hir::ExprAgain(destination) => {
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hir::ExprContinue(destination) => {
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self.s.word("continue")?;
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self.s.space()?;
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if let Some(label) = destination.label {
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@@ -621,7 +621,7 @@ fn hash_stable<W: StableHasherResult>(&self,
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ExprPath(path),
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ExprAddrOf(mutability, sub),
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ExprBreak(destination, sub),
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ExprAgain(destination),
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ExprContinue(destination),
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ExprRet(val),
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ExprInlineAsm(asm, inputs, outputs),
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ExprStruct(path, fields, base),
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@@ -479,7 +479,7 @@ pub fn walk_expr(&mut self, expr: &hir::Expr) {
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self.consume_exprs(inputs);
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}
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hir::ExprAgain(..) |
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hir::ExprContinue(..) |
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hir::ExprLit(..) => {}
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hir::ExprLoop(ref blk, _, _) => {
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@@ -502,7 +502,7 @@ fn visit_expr<'a, 'tcx>(ir: &mut IrMaps<'a, 'tcx>, expr: &'tcx Expr) {
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hir::ExprArray(..) | hir::ExprCall(..) | hir::ExprMethodCall(..) |
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hir::ExprTup(..) | hir::ExprBinary(..) | hir::ExprAddrOf(..) |
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hir::ExprCast(..) | hir::ExprUnary(..) | hir::ExprBreak(..) |
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hir::ExprAgain(_) | hir::ExprLit(_) | hir::ExprRet(..) |
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hir::ExprContinue(_) | hir::ExprLit(_) | hir::ExprRet(..) |
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hir::ExprBlock(..) | hir::ExprAssign(..) | hir::ExprAssignOp(..) |
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hir::ExprStruct(..) | hir::ExprRepeat(..) |
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hir::ExprInlineAsm(..) | hir::ExprBox(..) | hir::ExprYield(..) |
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@@ -1047,7 +1047,7 @@ fn propagate_through_expr(&mut self, expr: &Expr, succ: LiveNode)
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}
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}
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hir::ExprAgain(label) => {
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hir::ExprContinue(label) => {
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// Find which label this expr continues to
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let sc = match label.target_id {
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Ok(node_id) => node_id,
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@@ -1431,7 +1431,7 @@ fn check_expr<'a, 'tcx>(this: &mut Liveness<'a, 'tcx>, expr: &'tcx Expr) {
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hir::ExprIndex(..) | hir::ExprField(..) |
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hir::ExprArray(..) | hir::ExprTup(..) | hir::ExprBinary(..) |
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hir::ExprCast(..) | hir::ExprUnary(..) | hir::ExprRet(..) |
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hir::ExprBreak(..) | hir::ExprAgain(..) | hir::ExprLit(_) |
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hir::ExprBreak(..) | hir::ExprContinue(..) | hir::ExprLit(_) |
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hir::ExprBlock(..) | hir::ExprAddrOf(..) |
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hir::ExprStruct(..) | hir::ExprRepeat(..) |
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hir::ExprClosure(..) | hir::ExprPath(_) | hir::ExprYield(..) |
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@@ -686,7 +686,7 @@ pub fn cat_expr_unadjusted(&self, expr: &hir::Expr) -> McResult<cmt_<'tcx>> {
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hir::ExprBinary(..) | hir::ExprWhile(..) |
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hir::ExprBlock(..) | hir::ExprLoop(..) | hir::ExprMatch(..) |
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hir::ExprLit(..) | hir::ExprBreak(..) |
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hir::ExprAgain(..) | hir::ExprStruct(..) | hir::ExprRepeat(..) |
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hir::ExprContinue(..) | hir::ExprStruct(..) | hir::ExprRepeat(..) |
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hir::ExprInlineAsm(..) | hir::ExprBox(..) => {
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Ok(self.cat_rvalue_node(expr.id(), expr.span(), expr_ty))
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}
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@@ -543,7 +543,7 @@ fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
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Err(err) => bug!("invalid loop id for break: {}", err)
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}
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}
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hir::ExprAgain(dest) => {
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hir::ExprContinue(dest) => {
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match dest.target_id {
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Ok(loop_id) => ExprKind::Continue {
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label: region::Scope::Node(cx.tcx.hir.node_to_hir_id(loop_id).local_id),
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@@ -148,7 +148,7 @@ fn visit_expr(&mut self, e: &'hir hir::Expr) {
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self.require_break_cx("break", e.span);
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}
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hir::ExprAgain(label) => {
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hir::ExprContinue(label) => {
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self.require_label_in_labeled_block(e.span, &label, "continue");
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match label.target_id {
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@@ -469,7 +469,7 @@ fn check_expr<'a, 'tcx>(v: &mut CheckCrateVisitor<'a, 'tcx>, e: &hir::Expr, node
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// More control flow (also not very meaningful).
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hir::ExprBreak(..) |
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hir::ExprAgain(_) |
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hir::ExprContinue(_) |
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hir::ExprRet(_) |
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// Generator expressions
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+537
-537
@@ -2331,7 +2331,7 @@ fn is_place_expr(&self, expr: &hir::Expr) -> bool {
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hir::ExprRepeat(..) |
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hir::ExprArray(..) |
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hir::ExprBreak(..) |
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hir::ExprAgain(..) |
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hir::ExprContinue(..) |
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hir::ExprRet(..) |
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hir::ExprWhile(..) |
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hir::ExprLoop(..) |
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@@ -3611,579 +3611,579 @@ fn check_expr_kind(&self,
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let tcx = self.tcx;
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let id = expr.id;
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match expr.node {
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hir::ExprBox(ref subexpr) => {
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let expected_inner = expected.to_option(self).map_or(NoExpectation, |ty| {
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match ty.sty {
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ty::TyAdt(def, _) if def.is_box()
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=> Expectation::rvalue_hint(self, ty.boxed_ty()),
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_ => NoExpectation
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}
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});
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let referent_ty = self.check_expr_with_expectation(subexpr, expected_inner);
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tcx.mk_box(referent_ty)
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}
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hir::ExprBox(ref subexpr) => {
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let expected_inner = expected.to_option(self).map_or(NoExpectation, |ty| {
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match ty.sty {
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ty::TyAdt(def, _) if def.is_box()
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=> Expectation::rvalue_hint(self, ty.boxed_ty()),
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_ => NoExpectation
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}
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});
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let referent_ty = self.check_expr_with_expectation(subexpr, expected_inner);
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tcx.mk_box(referent_ty)
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}
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hir::ExprLit(ref lit) => {
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self.check_lit(&lit, expected)
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}
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hir::ExprBinary(op, ref lhs, ref rhs) => {
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self.check_binop(expr, op, lhs, rhs)
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}
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hir::ExprAssignOp(op, ref lhs, ref rhs) => {
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self.check_binop_assign(expr, op, lhs, rhs)
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}
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hir::ExprUnary(unop, ref oprnd) => {
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let expected_inner = match unop {
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hir::UnNot | hir::UnNeg => {
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expected
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}
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hir::UnDeref => {
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NoExpectation
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}
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};
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let needs = match unop {
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hir::UnDeref => needs,
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_ => Needs::None
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};
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let mut oprnd_t = self.check_expr_with_expectation_and_needs(&oprnd,
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expected_inner,
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needs);
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if !oprnd_t.references_error() {
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oprnd_t = self.structurally_resolved_type(expr.span, oprnd_t);
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match unop {
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hir::ExprLit(ref lit) => {
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self.check_lit(&lit, expected)
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}
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hir::ExprBinary(op, ref lhs, ref rhs) => {
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self.check_binop(expr, op, lhs, rhs)
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}
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hir::ExprAssignOp(op, ref lhs, ref rhs) => {
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self.check_binop_assign(expr, op, lhs, rhs)
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}
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hir::ExprUnary(unop, ref oprnd) => {
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let expected_inner = match unop {
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hir::UnNot | hir::UnNeg => {
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expected
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}
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hir::UnDeref => {
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if let Some(mt) = oprnd_t.builtin_deref(true) {
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oprnd_t = mt.ty;
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} else if let Some(ok) = self.try_overloaded_deref(
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expr.span, oprnd_t, needs) {
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let method = self.register_infer_ok_obligations(ok);
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if let ty::TyRef(region, _, mutbl) = method.sig.inputs()[0].sty {
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let mutbl = match mutbl {
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hir::MutImmutable => AutoBorrowMutability::Immutable,
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hir::MutMutable => AutoBorrowMutability::Mutable {
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// (It shouldn't actually matter for unary ops whether
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// we enable two-phase borrows or not, since a unary
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// op has no additional operands.)
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allow_two_phase_borrow: AllowTwoPhase::No,
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}
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};
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self.apply_adjustments(oprnd, vec![Adjustment {
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kind: Adjust::Borrow(AutoBorrow::Ref(region, mutbl)),
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target: method.sig.inputs()[0]
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}]);
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NoExpectation
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}
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};
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let needs = match unop {
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hir::UnDeref => needs,
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_ => Needs::None
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};
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let mut oprnd_t = self.check_expr_with_expectation_and_needs(&oprnd,
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expected_inner,
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needs);
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if !oprnd_t.references_error() {
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oprnd_t = self.structurally_resolved_type(expr.span, oprnd_t);
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match unop {
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hir::UnDeref => {
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if let Some(mt) = oprnd_t.builtin_deref(true) {
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oprnd_t = mt.ty;
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} else if let Some(ok) = self.try_overloaded_deref(
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expr.span, oprnd_t, needs) {
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let method = self.register_infer_ok_obligations(ok);
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if let ty::TyRef(region, _, mutbl) = method.sig.inputs()[0].sty {
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let mutbl = match mutbl {
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hir::MutImmutable => AutoBorrowMutability::Immutable,
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hir::MutMutable => AutoBorrowMutability::Mutable {
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// (It shouldn't actually matter for unary ops whether
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// we enable two-phase borrows or not, since a unary
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// op has no additional operands.)
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allow_two_phase_borrow: AllowTwoPhase::No,
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}
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};
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self.apply_adjustments(oprnd, vec![Adjustment {
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kind: Adjust::Borrow(AutoBorrow::Ref(region, mutbl)),
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target: method.sig.inputs()[0]
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}]);
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}
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oprnd_t = self.make_overloaded_place_return_type(method).ty;
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self.write_method_call(expr.hir_id, method);
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} else {
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type_error_struct!(tcx.sess, expr.span, oprnd_t, E0614,
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"type `{}` cannot be dereferenced",
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oprnd_t).emit();
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oprnd_t = tcx.types.err;
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}
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oprnd_t = self.make_overloaded_place_return_type(method).ty;
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self.write_method_call(expr.hir_id, method);
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} else {
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type_error_struct!(tcx.sess, expr.span, oprnd_t, E0614,
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"type `{}` cannot be dereferenced",
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oprnd_t).emit();
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oprnd_t = tcx.types.err;
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}
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}
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hir::UnNot => {
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let result = self.check_user_unop(expr, oprnd_t, unop);
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// If it's builtin, we can reuse the type, this helps inference.
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if !(oprnd_t.is_integral() || oprnd_t.sty == ty::TyBool) {
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oprnd_t = result;
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hir::UnNot => {
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let result = self.check_user_unop(expr, oprnd_t, unop);
|
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// If it's builtin, we can reuse the type, this helps inference.
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if !(oprnd_t.is_integral() || oprnd_t.sty == ty::TyBool) {
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oprnd_t = result;
|
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}
|
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}
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}
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hir::UnNeg => {
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let result = self.check_user_unop(expr, oprnd_t, unop);
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// If it's builtin, we can reuse the type, this helps inference.
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if !(oprnd_t.is_integral() || oprnd_t.is_fp()) {
|
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oprnd_t = result;
|
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hir::UnNeg => {
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let result = self.check_user_unop(expr, oprnd_t, unop);
|
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// If it's builtin, we can reuse the type, this helps inference.
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if !(oprnd_t.is_integral() || oprnd_t.is_fp()) {
|
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oprnd_t = result;
|
||||
}
|
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}
|
||||
}
|
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}
|
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oprnd_t
|
||||
}
|
||||
oprnd_t
|
||||
}
|
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hir::ExprAddrOf(mutbl, ref oprnd) => {
|
||||
let hint = expected.only_has_type(self).map_or(NoExpectation, |ty| {
|
||||
match ty.sty {
|
||||
ty::TyRef(_, ty, _) | ty::TyRawPtr(ty::TypeAndMut { ty, .. }) => {
|
||||
if self.is_place_expr(&oprnd) {
|
||||
// Places may legitimately have unsized types.
|
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// For example, dereferences of a fat pointer and
|
||||
// the last field of a struct can be unsized.
|
||||
ExpectHasType(ty)
|
||||
} else {
|
||||
Expectation::rvalue_hint(self, ty)
|
||||
hir::ExprAddrOf(mutbl, ref oprnd) => {
|
||||
let hint = expected.only_has_type(self).map_or(NoExpectation, |ty| {
|
||||
match ty.sty {
|
||||
ty::TyRef(_, ty, _) | ty::TyRawPtr(ty::TypeAndMut { ty, .. }) => {
|
||||
if self.is_place_expr(&oprnd) {
|
||||
// Places may legitimately have unsized types.
|
||||
// For example, dereferences of a fat pointer and
|
||||
// the last field of a struct can be unsized.
|
||||
ExpectHasType(ty)
|
||||
} else {
|
||||
Expectation::rvalue_hint(self, ty)
|
||||
}
|
||||
}
|
||||
_ => NoExpectation
|
||||
}
|
||||
_ => NoExpectation
|
||||
}
|
||||
});
|
||||
let needs = Needs::maybe_mut_place(mutbl);
|
||||
let ty = self.check_expr_with_expectation_and_needs(&oprnd, hint, needs);
|
||||
});
|
||||
let needs = Needs::maybe_mut_place(mutbl);
|
||||
let ty = self.check_expr_with_expectation_and_needs(&oprnd, hint, needs);
|
||||
|
||||
let tm = ty::TypeAndMut { ty: ty, mutbl: mutbl };
|
||||
if tm.ty.references_error() {
|
||||
tcx.types.err
|
||||
} else {
|
||||
// Note: at this point, we cannot say what the best lifetime
|
||||
// is to use for resulting pointer. We want to use the
|
||||
// shortest lifetime possible so as to avoid spurious borrowck
|
||||
// errors. Moreover, the longest lifetime will depend on the
|
||||
// precise details of the value whose address is being taken
|
||||
// (and how long it is valid), which we don't know yet until type
|
||||
// inference is complete.
|
||||
//
|
||||
// Therefore, here we simply generate a region variable. The
|
||||
// region inferencer will then select the ultimate value.
|
||||
// Finally, borrowck is charged with guaranteeing that the
|
||||
// value whose address was taken can actually be made to live
|
||||
// as long as it needs to live.
|
||||
let region = self.next_region_var(infer::AddrOfRegion(expr.span));
|
||||
tcx.mk_ref(region, tm)
|
||||
}
|
||||
}
|
||||
hir::ExprPath(ref qpath) => {
|
||||
let (def, opt_ty, segments) = self.resolve_ty_and_def_ufcs(qpath,
|
||||
expr.id, expr.span);
|
||||
let ty = if def != Def::Err {
|
||||
self.instantiate_value_path(segments, opt_ty, def, expr.span, id)
|
||||
} else {
|
||||
self.set_tainted_by_errors();
|
||||
tcx.types.err
|
||||
};
|
||||
|
||||
// We always require that the type provided as the value for
|
||||
// a type parameter outlives the moment of instantiation.
|
||||
let substs = self.tables.borrow().node_substs(expr.hir_id);
|
||||
self.add_wf_bounds(substs, expr);
|
||||
|
||||
ty
|
||||
}
|
||||
hir::ExprInlineAsm(_, ref outputs, ref inputs) => {
|
||||
for output in outputs {
|
||||
self.check_expr(output);
|
||||
}
|
||||
for input in inputs {
|
||||
self.check_expr(input);
|
||||
}
|
||||
tcx.mk_nil()
|
||||
}
|
||||
hir::ExprBreak(destination, ref expr_opt) => {
|
||||
if let Ok(target_id) = destination.target_id {
|
||||
let (e_ty, cause);
|
||||
if let Some(ref e) = *expr_opt {
|
||||
// If this is a break with a value, we need to type-check
|
||||
// the expression. Get an expected type from the loop context.
|
||||
let opt_coerce_to = {
|
||||
let mut enclosing_breakables = self.enclosing_breakables.borrow_mut();
|
||||
enclosing_breakables.find_breakable(target_id)
|
||||
.coerce
|
||||
.as_ref()
|
||||
.map(|coerce| coerce.expected_ty())
|
||||
};
|
||||
|
||||
// If the loop context is not a `loop { }`, then break with
|
||||
// a value is illegal, and `opt_coerce_to` will be `None`.
|
||||
// Just set expectation to error in that case.
|
||||
let coerce_to = opt_coerce_to.unwrap_or(tcx.types.err);
|
||||
|
||||
// Recurse without `enclosing_breakables` borrowed.
|
||||
e_ty = self.check_expr_with_hint(e, coerce_to);
|
||||
cause = self.misc(e.span);
|
||||
} else {
|
||||
// Otherwise, this is a break *without* a value. That's
|
||||
// always legal, and is equivalent to `break ()`.
|
||||
e_ty = tcx.mk_nil();
|
||||
cause = self.misc(expr.span);
|
||||
}
|
||||
|
||||
// Now that we have type-checked `expr_opt`, borrow
|
||||
// the `enclosing_loops` field and let's coerce the
|
||||
// type of `expr_opt` into what is expected.
|
||||
let mut enclosing_breakables = self.enclosing_breakables.borrow_mut();
|
||||
let ctxt = enclosing_breakables.find_breakable(target_id);
|
||||
if let Some(ref mut coerce) = ctxt.coerce {
|
||||
if let Some(ref e) = *expr_opt {
|
||||
coerce.coerce(self, &cause, e, e_ty);
|
||||
} else {
|
||||
assert!(e_ty.is_nil());
|
||||
coerce.coerce_forced_unit(self, &cause, &mut |_| (), true);
|
||||
}
|
||||
} else {
|
||||
// If `ctxt.coerce` is `None`, we can just ignore
|
||||
// the type of the expresison. This is because
|
||||
// either this was a break *without* a value, in
|
||||
// which case it is always a legal type (`()`), or
|
||||
// else an error would have been flagged by the
|
||||
// `loops` pass for using break with an expression
|
||||
// where you are not supposed to.
|
||||
assert!(expr_opt.is_none() || self.tcx.sess.err_count() > 0);
|
||||
}
|
||||
|
||||
ctxt.may_break = true;
|
||||
|
||||
// the type of a `break` is always `!`, since it diverges
|
||||
tcx.types.never
|
||||
} else {
|
||||
// Otherwise, we failed to find the enclosing loop;
|
||||
// this can only happen if the `break` was not
|
||||
// inside a loop at all, which is caught by the
|
||||
// loop-checking pass.
|
||||
assert!(self.tcx.sess.err_count() > 0);
|
||||
|
||||
// We still need to assign a type to the inner expression to
|
||||
// prevent the ICE in #43162.
|
||||
if let Some(ref e) = *expr_opt {
|
||||
self.check_expr_with_hint(e, tcx.types.err);
|
||||
|
||||
// ... except when we try to 'break rust;'.
|
||||
// ICE this expression in particular (see #43162).
|
||||
if let hir::ExprPath(hir::QPath::Resolved(_, ref path)) = e.node {
|
||||
if path.segments.len() == 1 && path.segments[0].name == "rust" {
|
||||
fatally_break_rust(self.tcx.sess);
|
||||
}
|
||||
}
|
||||
}
|
||||
// There was an error, make typecheck fail
|
||||
tcx.types.err
|
||||
}
|
||||
|
||||
}
|
||||
hir::ExprAgain(_) => { tcx.types.never }
|
||||
hir::ExprRet(ref expr_opt) => {
|
||||
if self.ret_coercion.is_none() {
|
||||
struct_span_err!(self.tcx.sess, expr.span, E0572,
|
||||
"return statement outside of function body").emit();
|
||||
} else if let Some(ref e) = *expr_opt {
|
||||
self.check_return_expr(e);
|
||||
} else {
|
||||
let mut coercion = self.ret_coercion.as_ref().unwrap().borrow_mut();
|
||||
let cause = self.cause(expr.span, ObligationCauseCode::ReturnNoExpression);
|
||||
coercion.coerce_forced_unit(self, &cause, &mut |_| (), true);
|
||||
}
|
||||
tcx.types.never
|
||||
}
|
||||
hir::ExprAssign(ref lhs, ref rhs) => {
|
||||
let lhs_ty = self.check_expr_with_needs(&lhs, Needs::MutPlace);
|
||||
|
||||
let rhs_ty = self.check_expr_coercable_to_type(&rhs, lhs_ty);
|
||||
|
||||
match expected {
|
||||
ExpectIfCondition => {
|
||||
self.tcx.sess.delay_span_bug(lhs.span, "invalid lhs expression in if;\
|
||||
expected error elsehwere");
|
||||
}
|
||||
_ => {
|
||||
// Only check this if not in an `if` condition, as the
|
||||
// mistyped comparison help is more appropriate.
|
||||
if !self.is_place_expr(&lhs) {
|
||||
struct_span_err!(self.tcx.sess, expr.span, E0070,
|
||||
"invalid left-hand side expression")
|
||||
.span_label(expr.span, "left-hand of expression not valid")
|
||||
.emit();
|
||||
}
|
||||
let tm = ty::TypeAndMut { ty: ty, mutbl: mutbl };
|
||||
if tm.ty.references_error() {
|
||||
tcx.types.err
|
||||
} else {
|
||||
// Note: at this point, we cannot say what the best lifetime
|
||||
// is to use for resulting pointer. We want to use the
|
||||
// shortest lifetime possible so as to avoid spurious borrowck
|
||||
// errors. Moreover, the longest lifetime will depend on the
|
||||
// precise details of the value whose address is being taken
|
||||
// (and how long it is valid), which we don't know yet until type
|
||||
// inference is complete.
|
||||
//
|
||||
// Therefore, here we simply generate a region variable. The
|
||||
// region inferencer will then select the ultimate value.
|
||||
// Finally, borrowck is charged with guaranteeing that the
|
||||
// value whose address was taken can actually be made to live
|
||||
// as long as it needs to live.
|
||||
let region = self.next_region_var(infer::AddrOfRegion(expr.span));
|
||||
tcx.mk_ref(region, tm)
|
||||
}
|
||||
}
|
||||
hir::ExprPath(ref qpath) => {
|
||||
let (def, opt_ty, segs) = self.resolve_ty_and_def_ufcs(qpath, expr.id, expr.span);
|
||||
let ty = if def != Def::Err {
|
||||
self.instantiate_value_path(segs, opt_ty, def, expr.span, id)
|
||||
} else {
|
||||
self.set_tainted_by_errors();
|
||||
tcx.types.err
|
||||
};
|
||||
|
||||
self.require_type_is_sized(lhs_ty, lhs.span, traits::AssignmentLhsSized);
|
||||
// We always require that the type provided as the value for
|
||||
// a type parameter outlives the moment of instantiation.
|
||||
let substs = self.tables.borrow().node_substs(expr.hir_id);
|
||||
self.add_wf_bounds(substs, expr);
|
||||
|
||||
if lhs_ty.references_error() || rhs_ty.references_error() {
|
||||
tcx.types.err
|
||||
} else {
|
||||
ty
|
||||
}
|
||||
hir::ExprInlineAsm(_, ref outputs, ref inputs) => {
|
||||
for output in outputs {
|
||||
self.check_expr(output);
|
||||
}
|
||||
for input in inputs {
|
||||
self.check_expr(input);
|
||||
}
|
||||
tcx.mk_nil()
|
||||
}
|
||||
}
|
||||
hir::ExprIf(ref cond, ref then_expr, ref opt_else_expr) => {
|
||||
self.check_then_else(&cond, then_expr, opt_else_expr.as_ref().map(|e| &**e),
|
||||
expr.span, expected)
|
||||
}
|
||||
hir::ExprWhile(ref cond, ref body, _) => {
|
||||
let ctxt = BreakableCtxt {
|
||||
// cannot use break with a value from a while loop
|
||||
coerce: None,
|
||||
may_break: false, // Will get updated if/when we find a `break`.
|
||||
};
|
||||
hir::ExprBreak(destination, ref expr_opt) => {
|
||||
if let Ok(target_id) = destination.target_id {
|
||||
let (e_ty, cause);
|
||||
if let Some(ref e) = *expr_opt {
|
||||
// If this is a break with a value, we need to type-check
|
||||
// the expression. Get an expected type from the loop context.
|
||||
let opt_coerce_to = {
|
||||
let mut enclosing_breakables = self.enclosing_breakables.borrow_mut();
|
||||
enclosing_breakables.find_breakable(target_id)
|
||||
.coerce
|
||||
.as_ref()
|
||||
.map(|coerce| coerce.expected_ty())
|
||||
};
|
||||
|
||||
let (ctxt, ()) = self.with_breakable_ctxt(expr.id, ctxt, || {
|
||||
self.check_expr_has_type_or_error(&cond, tcx.types.bool);
|
||||
let cond_diverging = self.diverges.get();
|
||||
self.check_block_no_value(&body);
|
||||
// If the loop context is not a `loop { }`, then break with
|
||||
// a value is illegal, and `opt_coerce_to` will be `None`.
|
||||
// Just set expectation to error in that case.
|
||||
let coerce_to = opt_coerce_to.unwrap_or(tcx.types.err);
|
||||
|
||||
// We may never reach the body so it diverging means nothing.
|
||||
self.diverges.set(cond_diverging);
|
||||
});
|
||||
|
||||
if ctxt.may_break {
|
||||
// No way to know whether it's diverging because
|
||||
// of a `break` or an outer `break` or `return`.
|
||||
self.diverges.set(Diverges::Maybe);
|
||||
}
|
||||
|
||||
self.tcx.mk_nil()
|
||||
}
|
||||
hir::ExprLoop(ref body, _, source) => {
|
||||
let coerce = match source {
|
||||
// you can only use break with a value from a normal `loop { }`
|
||||
hir::LoopSource::Loop => {
|
||||
let coerce_to = expected.coercion_target_type(self, body.span);
|
||||
Some(CoerceMany::new(coerce_to))
|
||||
}
|
||||
|
||||
hir::LoopSource::WhileLet |
|
||||
hir::LoopSource::ForLoop => {
|
||||
None
|
||||
}
|
||||
};
|
||||
|
||||
let ctxt = BreakableCtxt {
|
||||
coerce,
|
||||
may_break: false, // Will get updated if/when we find a `break`.
|
||||
};
|
||||
|
||||
let (ctxt, ()) = self.with_breakable_ctxt(expr.id, ctxt, || {
|
||||
self.check_block_no_value(&body);
|
||||
});
|
||||
|
||||
if ctxt.may_break {
|
||||
// No way to know whether it's diverging because
|
||||
// of a `break` or an outer `break` or `return`.
|
||||
self.diverges.set(Diverges::Maybe);
|
||||
}
|
||||
|
||||
// If we permit break with a value, then result type is
|
||||
// the LUB of the breaks (possibly ! if none); else, it
|
||||
// is nil. This makes sense because infinite loops
|
||||
// (which would have type !) are only possible iff we
|
||||
// permit break with a value [1].
|
||||
assert!(ctxt.coerce.is_some() || ctxt.may_break); // [1]
|
||||
ctxt.coerce.map(|c| c.complete(self)).unwrap_or(self.tcx.mk_nil())
|
||||
}
|
||||
hir::ExprMatch(ref discrim, ref arms, match_src) => {
|
||||
self.check_match(expr, &discrim, arms, expected, match_src)
|
||||
}
|
||||
hir::ExprClosure(capture, ref decl, body_id, _, gen) => {
|
||||
self.check_expr_closure(expr, capture, &decl, body_id, gen, expected)
|
||||
}
|
||||
hir::ExprBlock(ref body, _) => {
|
||||
self.check_block_with_expected(&body, expected)
|
||||
}
|
||||
hir::ExprCall(ref callee, ref args) => {
|
||||
self.check_call(expr, &callee, args, expected)
|
||||
}
|
||||
hir::ExprMethodCall(ref segment, span, ref args) => {
|
||||
self.check_method_call(expr, segment, span, args, expected, needs)
|
||||
}
|
||||
hir::ExprCast(ref e, ref t) => {
|
||||
// Find the type of `e`. Supply hints based on the type we are casting to,
|
||||
// if appropriate.
|
||||
let t_cast = self.to_ty(t);
|
||||
let t_cast = self.resolve_type_vars_if_possible(&t_cast);
|
||||
let t_expr = self.check_expr_with_expectation(e, ExpectCastableToType(t_cast));
|
||||
let t_cast = self.resolve_type_vars_if_possible(&t_cast);
|
||||
|
||||
// Eagerly check for some obvious errors.
|
||||
if t_expr.references_error() || t_cast.references_error() {
|
||||
tcx.types.err
|
||||
} else {
|
||||
// Defer other checks until we're done type checking.
|
||||
let mut deferred_cast_checks = self.deferred_cast_checks.borrow_mut();
|
||||
match cast::CastCheck::new(self, e, t_expr, t_cast, t.span, expr.span) {
|
||||
Ok(cast_check) => {
|
||||
deferred_cast_checks.push(cast_check);
|
||||
t_cast
|
||||
// Recurse without `enclosing_breakables` borrowed.
|
||||
e_ty = self.check_expr_with_hint(e, coerce_to);
|
||||
cause = self.misc(e.span);
|
||||
} else {
|
||||
// Otherwise, this is a break *without* a value. That's
|
||||
// always legal, and is equivalent to `break ()`.
|
||||
e_ty = tcx.mk_nil();
|
||||
cause = self.misc(expr.span);
|
||||
}
|
||||
Err(ErrorReported) => {
|
||||
tcx.types.err
|
||||
|
||||
// Now that we have type-checked `expr_opt`, borrow
|
||||
// the `enclosing_loops` field and let's coerce the
|
||||
// type of `expr_opt` into what is expected.
|
||||
let mut enclosing_breakables = self.enclosing_breakables.borrow_mut();
|
||||
let ctxt = enclosing_breakables.find_breakable(target_id);
|
||||
if let Some(ref mut coerce) = ctxt.coerce {
|
||||
if let Some(ref e) = *expr_opt {
|
||||
coerce.coerce(self, &cause, e, e_ty);
|
||||
} else {
|
||||
assert!(e_ty.is_nil());
|
||||
coerce.coerce_forced_unit(self, &cause, &mut |_| (), true);
|
||||
}
|
||||
} else {
|
||||
// If `ctxt.coerce` is `None`, we can just ignore
|
||||
// the type of the expresison. This is because
|
||||
// either this was a break *without* a value, in
|
||||
// which case it is always a legal type (`()`), or
|
||||
// else an error would have been flagged by the
|
||||
// `loops` pass for using break with an expression
|
||||
// where you are not supposed to.
|
||||
assert!(expr_opt.is_none() || self.tcx.sess.err_count() > 0);
|
||||
}
|
||||
|
||||
ctxt.may_break = true;
|
||||
|
||||
// the type of a `break` is always `!`, since it diverges
|
||||
tcx.types.never
|
||||
} else {
|
||||
// Otherwise, we failed to find the enclosing loop;
|
||||
// this can only happen if the `break` was not
|
||||
// inside a loop at all, which is caught by the
|
||||
// loop-checking pass.
|
||||
assert!(self.tcx.sess.err_count() > 0);
|
||||
|
||||
// We still need to assign a type to the inner expression to
|
||||
// prevent the ICE in #43162.
|
||||
if let Some(ref e) = *expr_opt {
|
||||
self.check_expr_with_hint(e, tcx.types.err);
|
||||
|
||||
// ... except when we try to 'break rust;'.
|
||||
// ICE this expression in particular (see #43162).
|
||||
if let hir::ExprPath(hir::QPath::Resolved(_, ref path)) = e.node {
|
||||
if path.segments.len() == 1 && path.segments[0].name == "rust" {
|
||||
fatally_break_rust(self.tcx.sess);
|
||||
}
|
||||
}
|
||||
}
|
||||
// There was an error, make typecheck fail
|
||||
tcx.types.err
|
||||
}
|
||||
|
||||
}
|
||||
hir::ExprContinue(_) => { tcx.types.never }
|
||||
hir::ExprRet(ref expr_opt) => {
|
||||
if self.ret_coercion.is_none() {
|
||||
struct_span_err!(self.tcx.sess, expr.span, E0572,
|
||||
"return statement outside of function body").emit();
|
||||
} else if let Some(ref e) = *expr_opt {
|
||||
self.check_return_expr(e);
|
||||
} else {
|
||||
let mut coercion = self.ret_coercion.as_ref().unwrap().borrow_mut();
|
||||
let cause = self.cause(expr.span, ObligationCauseCode::ReturnNoExpression);
|
||||
coercion.coerce_forced_unit(self, &cause, &mut |_| (), true);
|
||||
}
|
||||
tcx.types.never
|
||||
}
|
||||
hir::ExprAssign(ref lhs, ref rhs) => {
|
||||
let lhs_ty = self.check_expr_with_needs(&lhs, Needs::MutPlace);
|
||||
|
||||
let rhs_ty = self.check_expr_coercable_to_type(&rhs, lhs_ty);
|
||||
|
||||
match expected {
|
||||
ExpectIfCondition => {
|
||||
self.tcx.sess.delay_span_bug(lhs.span, "invalid lhs expression in if;\
|
||||
expected error elsehwere");
|
||||
}
|
||||
_ => {
|
||||
// Only check this if not in an `if` condition, as the
|
||||
// mistyped comparison help is more appropriate.
|
||||
if !self.is_place_expr(&lhs) {
|
||||
struct_span_err!(self.tcx.sess, expr.span, E0070,
|
||||
"invalid left-hand side expression")
|
||||
.span_label(expr.span, "left-hand of expression not valid")
|
||||
.emit();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
self.require_type_is_sized(lhs_ty, lhs.span, traits::AssignmentLhsSized);
|
||||
|
||||
if lhs_ty.references_error() || rhs_ty.references_error() {
|
||||
tcx.types.err
|
||||
} else {
|
||||
tcx.mk_nil()
|
||||
}
|
||||
}
|
||||
hir::ExprIf(ref cond, ref then_expr, ref opt_else_expr) => {
|
||||
self.check_then_else(&cond, then_expr, opt_else_expr.as_ref().map(|e| &**e),
|
||||
expr.span, expected)
|
||||
}
|
||||
hir::ExprWhile(ref cond, ref body, _) => {
|
||||
let ctxt = BreakableCtxt {
|
||||
// cannot use break with a value from a while loop
|
||||
coerce: None,
|
||||
may_break: false, // Will get updated if/when we find a `break`.
|
||||
};
|
||||
|
||||
let (ctxt, ()) = self.with_breakable_ctxt(expr.id, ctxt, || {
|
||||
self.check_expr_has_type_or_error(&cond, tcx.types.bool);
|
||||
let cond_diverging = self.diverges.get();
|
||||
self.check_block_no_value(&body);
|
||||
|
||||
// We may never reach the body so it diverging means nothing.
|
||||
self.diverges.set(cond_diverging);
|
||||
});
|
||||
|
||||
if ctxt.may_break {
|
||||
// No way to know whether it's diverging because
|
||||
// of a `break` or an outer `break` or `return`.
|
||||
self.diverges.set(Diverges::Maybe);
|
||||
}
|
||||
|
||||
self.tcx.mk_nil()
|
||||
}
|
||||
hir::ExprLoop(ref body, _, source) => {
|
||||
let coerce = match source {
|
||||
// you can only use break with a value from a normal `loop { }`
|
||||
hir::LoopSource::Loop => {
|
||||
let coerce_to = expected.coercion_target_type(self, body.span);
|
||||
Some(CoerceMany::new(coerce_to))
|
||||
}
|
||||
|
||||
hir::LoopSource::WhileLet |
|
||||
hir::LoopSource::ForLoop => {
|
||||
None
|
||||
}
|
||||
};
|
||||
|
||||
let ctxt = BreakableCtxt {
|
||||
coerce,
|
||||
may_break: false, // Will get updated if/when we find a `break`.
|
||||
};
|
||||
|
||||
let (ctxt, ()) = self.with_breakable_ctxt(expr.id, ctxt, || {
|
||||
self.check_block_no_value(&body);
|
||||
});
|
||||
|
||||
if ctxt.may_break {
|
||||
// No way to know whether it's diverging because
|
||||
// of a `break` or an outer `break` or `return`.
|
||||
self.diverges.set(Diverges::Maybe);
|
||||
}
|
||||
|
||||
// If we permit break with a value, then result type is
|
||||
// the LUB of the breaks (possibly ! if none); else, it
|
||||
// is nil. This makes sense because infinite loops
|
||||
// (which would have type !) are only possible iff we
|
||||
// permit break with a value [1].
|
||||
assert!(ctxt.coerce.is_some() || ctxt.may_break); // [1]
|
||||
ctxt.coerce.map(|c| c.complete(self)).unwrap_or(self.tcx.mk_nil())
|
||||
}
|
||||
hir::ExprMatch(ref discrim, ref arms, match_src) => {
|
||||
self.check_match(expr, &discrim, arms, expected, match_src)
|
||||
}
|
||||
hir::ExprClosure(capture, ref decl, body_id, _, gen) => {
|
||||
self.check_expr_closure(expr, capture, &decl, body_id, gen, expected)
|
||||
}
|
||||
hir::ExprBlock(ref body, _) => {
|
||||
self.check_block_with_expected(&body, expected)
|
||||
}
|
||||
hir::ExprCall(ref callee, ref args) => {
|
||||
self.check_call(expr, &callee, args, expected)
|
||||
}
|
||||
hir::ExprMethodCall(ref segment, span, ref args) => {
|
||||
self.check_method_call(expr, segment, span, args, expected, needs)
|
||||
}
|
||||
hir::ExprCast(ref e, ref t) => {
|
||||
// Find the type of `e`. Supply hints based on the type we are casting to,
|
||||
// if appropriate.
|
||||
let t_cast = self.to_ty(t);
|
||||
let t_cast = self.resolve_type_vars_if_possible(&t_cast);
|
||||
let t_expr = self.check_expr_with_expectation(e, ExpectCastableToType(t_cast));
|
||||
let t_cast = self.resolve_type_vars_if_possible(&t_cast);
|
||||
|
||||
// Eagerly check for some obvious errors.
|
||||
if t_expr.references_error() || t_cast.references_error() {
|
||||
tcx.types.err
|
||||
} else {
|
||||
// Defer other checks until we're done type checking.
|
||||
let mut deferred_cast_checks = self.deferred_cast_checks.borrow_mut();
|
||||
match cast::CastCheck::new(self, e, t_expr, t_cast, t.span, expr.span) {
|
||||
Ok(cast_check) => {
|
||||
deferred_cast_checks.push(cast_check);
|
||||
t_cast
|
||||
}
|
||||
Err(ErrorReported) => {
|
||||
tcx.types.err
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
hir::ExprType(ref e, ref t) => {
|
||||
let typ = self.to_ty(&t);
|
||||
self.check_expr_eq_type(&e, typ);
|
||||
typ
|
||||
}
|
||||
hir::ExprArray(ref args) => {
|
||||
let uty = expected.to_option(self).and_then(|uty| {
|
||||
match uty.sty {
|
||||
ty::TyArray(ty, _) | ty::TySlice(ty) => Some(ty),
|
||||
_ => None
|
||||
}
|
||||
});
|
||||
|
||||
let element_ty = if !args.is_empty() {
|
||||
let coerce_to = uty.unwrap_or_else(
|
||||
|| self.next_ty_var(TypeVariableOrigin::TypeInference(expr.span)));
|
||||
let mut coerce = CoerceMany::with_coercion_sites(coerce_to, args);
|
||||
assert_eq!(self.diverges.get(), Diverges::Maybe);
|
||||
for e in args {
|
||||
let e_ty = self.check_expr_with_hint(e, coerce_to);
|
||||
let cause = self.misc(e.span);
|
||||
coerce.coerce(self, &cause, e, e_ty);
|
||||
}
|
||||
coerce.complete(self)
|
||||
} else {
|
||||
self.next_ty_var(TypeVariableOrigin::TypeInference(expr.span))
|
||||
};
|
||||
tcx.mk_array(element_ty, args.len() as u64)
|
||||
}
|
||||
hir::ExprRepeat(ref element, ref count) => {
|
||||
let count_def_id = tcx.hir.local_def_id(count.id);
|
||||
let param_env = ty::ParamEnv::empty();
|
||||
let substs = Substs::identity_for_item(tcx.global_tcx(), count_def_id);
|
||||
let instance = ty::Instance::resolve(
|
||||
tcx.global_tcx(),
|
||||
param_env,
|
||||
count_def_id,
|
||||
substs,
|
||||
).unwrap();
|
||||
let global_id = GlobalId {
|
||||
instance,
|
||||
promoted: None
|
||||
};
|
||||
let count = tcx.const_eval(param_env.and(global_id));
|
||||
|
||||
if let Err(ref err) = count {
|
||||
err.report_as_error(
|
||||
tcx.at(tcx.def_span(count_def_id)),
|
||||
"could not evaluate repeat length",
|
||||
);
|
||||
hir::ExprType(ref e, ref t) => {
|
||||
let ty = self.to_ty(&t);
|
||||
self.check_expr_eq_type(&e, ty);
|
||||
ty
|
||||
}
|
||||
|
||||
let uty = match expected {
|
||||
ExpectHasType(uty) => {
|
||||
hir::ExprArray(ref args) => {
|
||||
let uty = expected.to_option(self).and_then(|uty| {
|
||||
match uty.sty {
|
||||
ty::TyArray(ty, _) | ty::TySlice(ty) => Some(ty),
|
||||
_ => None
|
||||
}
|
||||
}
|
||||
_ => None
|
||||
};
|
||||
});
|
||||
|
||||
let (element_ty, t) = match uty {
|
||||
Some(uty) => {
|
||||
self.check_expr_coercable_to_type(&element, uty);
|
||||
(uty, uty)
|
||||
}
|
||||
None => {
|
||||
let t: Ty = self.next_ty_var(TypeVariableOrigin::MiscVariable(element.span));
|
||||
let element_ty = self.check_expr_has_type_or_error(&element, t);
|
||||
(element_ty, t)
|
||||
}
|
||||
};
|
||||
|
||||
if let Ok(count) = count {
|
||||
let zero_or_one = count.assert_usize(tcx).map_or(false, |count| count <= 1);
|
||||
if !zero_or_one {
|
||||
// For [foo, ..n] where n > 1, `foo` must have
|
||||
// Copy type:
|
||||
let lang_item = self.tcx.require_lang_item(lang_items::CopyTraitLangItem);
|
||||
self.require_type_meets(t, expr.span, traits::RepeatVec, lang_item);
|
||||
}
|
||||
}
|
||||
|
||||
if element_ty.references_error() {
|
||||
tcx.types.err
|
||||
} else if let Ok(count) = count {
|
||||
tcx.mk_ty(ty::TyArray(t, count))
|
||||
} else {
|
||||
tcx.types.err
|
||||
}
|
||||
}
|
||||
hir::ExprTup(ref elts) => {
|
||||
let flds = expected.only_has_type(self).and_then(|ty| {
|
||||
let ty = self.resolve_type_vars_with_obligations(ty);
|
||||
match ty.sty {
|
||||
ty::TyTuple(ref flds) => Some(&flds[..]),
|
||||
_ => None
|
||||
}
|
||||
});
|
||||
|
||||
let elt_ts_iter = elts.iter().enumerate().map(|(i, e)| {
|
||||
let t = match flds {
|
||||
Some(ref fs) if i < fs.len() => {
|
||||
let ety = fs[i];
|
||||
self.check_expr_coercable_to_type(&e, ety);
|
||||
ety
|
||||
let element_ty = if !args.is_empty() {
|
||||
let coerce_to = uty.unwrap_or_else(
|
||||
|| self.next_ty_var(TypeVariableOrigin::TypeInference(expr.span)));
|
||||
let mut coerce = CoerceMany::with_coercion_sites(coerce_to, args);
|
||||
assert_eq!(self.diverges.get(), Diverges::Maybe);
|
||||
for e in args {
|
||||
let e_ty = self.check_expr_with_hint(e, coerce_to);
|
||||
let cause = self.misc(e.span);
|
||||
coerce.coerce(self, &cause, e, e_ty);
|
||||
}
|
||||
_ => {
|
||||
self.check_expr_with_expectation(&e, NoExpectation)
|
||||
coerce.complete(self)
|
||||
} else {
|
||||
self.next_ty_var(TypeVariableOrigin::TypeInference(expr.span))
|
||||
};
|
||||
tcx.mk_array(element_ty, args.len() as u64)
|
||||
}
|
||||
hir::ExprRepeat(ref element, ref count) => {
|
||||
let count_def_id = tcx.hir.local_def_id(count.id);
|
||||
let param_env = ty::ParamEnv::empty();
|
||||
let substs = Substs::identity_for_item(tcx.global_tcx(), count_def_id);
|
||||
let instance = ty::Instance::resolve(
|
||||
tcx.global_tcx(),
|
||||
param_env,
|
||||
count_def_id,
|
||||
substs,
|
||||
).unwrap();
|
||||
let global_id = GlobalId {
|
||||
instance,
|
||||
promoted: None
|
||||
};
|
||||
let count = tcx.const_eval(param_env.and(global_id));
|
||||
|
||||
if let Err(ref err) = count {
|
||||
err.report_as_error(
|
||||
tcx.at(tcx.def_span(count_def_id)),
|
||||
"could not evaluate repeat length",
|
||||
);
|
||||
}
|
||||
|
||||
let uty = match expected {
|
||||
ExpectHasType(uty) => {
|
||||
match uty.sty {
|
||||
ty::TyArray(ty, _) | ty::TySlice(ty) => Some(ty),
|
||||
_ => None
|
||||
}
|
||||
}
|
||||
_ => None
|
||||
};
|
||||
|
||||
let (element_ty, t) = match uty {
|
||||
Some(uty) => {
|
||||
self.check_expr_coercable_to_type(&element, uty);
|
||||
(uty, uty)
|
||||
}
|
||||
None => {
|
||||
let ty = self.next_ty_var(TypeVariableOrigin::MiscVariable(element.span));
|
||||
let element_ty = self.check_expr_has_type_or_error(&element, ty);
|
||||
(element_ty, ty)
|
||||
}
|
||||
};
|
||||
t
|
||||
});
|
||||
let tuple = tcx.mk_tup(elt_ts_iter);
|
||||
if tuple.references_error() {
|
||||
tcx.types.err
|
||||
} else {
|
||||
self.require_type_is_sized(tuple, expr.span, traits::TupleInitializerSized);
|
||||
tuple
|
||||
}
|
||||
}
|
||||
hir::ExprStruct(ref qpath, ref fields, ref base_expr) => {
|
||||
self.check_expr_struct(expr, expected, qpath, fields, base_expr)
|
||||
}
|
||||
hir::ExprField(ref base, field) => {
|
||||
self.check_field(expr, needs, &base, field)
|
||||
}
|
||||
hir::ExprIndex(ref base, ref idx) => {
|
||||
let base_t = self.check_expr_with_needs(&base, needs);
|
||||
let idx_t = self.check_expr(&idx);
|
||||
|
||||
if base_t.references_error() {
|
||||
base_t
|
||||
} else if idx_t.references_error() {
|
||||
idx_t
|
||||
} else {
|
||||
let base_t = self.structurally_resolved_type(base.span, base_t);
|
||||
match self.lookup_indexing(expr, base, base_t, idx_t, needs) {
|
||||
Some((index_ty, element_ty)) => {
|
||||
// two-phase not needed because index_ty is never mutable
|
||||
self.demand_coerce(idx, idx_t, index_ty, AllowTwoPhase::No);
|
||||
element_ty
|
||||
}
|
||||
None => {
|
||||
let mut err = type_error_struct!(tcx.sess, expr.span, base_t, E0608,
|
||||
"cannot index into a value of type `{}`",
|
||||
base_t);
|
||||
// Try to give some advice about indexing tuples.
|
||||
if let ty::TyTuple(..) = base_t.sty {
|
||||
let mut needs_note = true;
|
||||
// If the index is an integer, we can show the actual
|
||||
// fixed expression:
|
||||
if let hir::ExprLit(ref lit) = idx.node {
|
||||
if let ast::LitKind::Int(i,
|
||||
ast::LitIntType::Unsuffixed) = lit.node {
|
||||
let snip = tcx.sess.codemap().span_to_snippet(base.span);
|
||||
if let Ok(snip) = snip {
|
||||
err.span_suggestion(expr.span,
|
||||
"to access tuple elements, use",
|
||||
format!("{}.{}", snip, i));
|
||||
needs_note = false;
|
||||
}
|
||||
}
|
||||
}
|
||||
if needs_note {
|
||||
err.help("to access tuple elements, use tuple indexing \
|
||||
syntax (e.g. `tuple.0`)");
|
||||
}
|
||||
}
|
||||
err.emit();
|
||||
self.tcx.types.err
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
hir::ExprYield(ref value) => {
|
||||
match self.yield_ty {
|
||||
Some(ty) => {
|
||||
self.check_expr_coercable_to_type(&value, ty);
|
||||
if let Ok(count) = count {
|
||||
let zero_or_one = count.assert_usize(tcx).map_or(false, |count| count <= 1);
|
||||
if !zero_or_one {
|
||||
// For [foo, ..n] where n > 1, `foo` must have
|
||||
// Copy type:
|
||||
let lang_item = self.tcx.require_lang_item(lang_items::CopyTraitLangItem);
|
||||
self.require_type_meets(t, expr.span, traits::RepeatVec, lang_item);
|
||||
}
|
||||
}
|
||||
None => {
|
||||
struct_span_err!(self.tcx.sess, expr.span, E0627,
|
||||
"yield statement outside of generator literal").emit();
|
||||
|
||||
if element_ty.references_error() {
|
||||
tcx.types.err
|
||||
} else if let Ok(count) = count {
|
||||
tcx.mk_ty(ty::TyArray(t, count))
|
||||
} else {
|
||||
tcx.types.err
|
||||
}
|
||||
}
|
||||
tcx.mk_nil()
|
||||
}
|
||||
hir::ExprTup(ref elts) => {
|
||||
let flds = expected.only_has_type(self).and_then(|ty| {
|
||||
let ty = self.resolve_type_vars_with_obligations(ty);
|
||||
match ty.sty {
|
||||
ty::TyTuple(ref flds) => Some(&flds[..]),
|
||||
_ => None
|
||||
}
|
||||
});
|
||||
|
||||
let elt_ts_iter = elts.iter().enumerate().map(|(i, e)| {
|
||||
let t = match flds {
|
||||
Some(ref fs) if i < fs.len() => {
|
||||
let ety = fs[i];
|
||||
self.check_expr_coercable_to_type(&e, ety);
|
||||
ety
|
||||
}
|
||||
_ => {
|
||||
self.check_expr_with_expectation(&e, NoExpectation)
|
||||
}
|
||||
};
|
||||
t
|
||||
});
|
||||
let tuple = tcx.mk_tup(elt_ts_iter);
|
||||
if tuple.references_error() {
|
||||
tcx.types.err
|
||||
} else {
|
||||
self.require_type_is_sized(tuple, expr.span, traits::TupleInitializerSized);
|
||||
tuple
|
||||
}
|
||||
}
|
||||
hir::ExprStruct(ref qpath, ref fields, ref base_expr) => {
|
||||
self.check_expr_struct(expr, expected, qpath, fields, base_expr)
|
||||
}
|
||||
hir::ExprField(ref base, field) => {
|
||||
self.check_field(expr, needs, &base, field)
|
||||
}
|
||||
hir::ExprIndex(ref base, ref idx) => {
|
||||
let base_t = self.check_expr_with_needs(&base, needs);
|
||||
let idx_t = self.check_expr(&idx);
|
||||
|
||||
if base_t.references_error() {
|
||||
base_t
|
||||
} else if idx_t.references_error() {
|
||||
idx_t
|
||||
} else {
|
||||
let base_t = self.structurally_resolved_type(base.span, base_t);
|
||||
match self.lookup_indexing(expr, base, base_t, idx_t, needs) {
|
||||
Some((index_ty, element_ty)) => {
|
||||
// two-phase not needed because index_ty is never mutable
|
||||
self.demand_coerce(idx, idx_t, index_ty, AllowTwoPhase::No);
|
||||
element_ty
|
||||
}
|
||||
None => {
|
||||
let mut err =
|
||||
type_error_struct!(tcx.sess, expr.span, base_t, E0608,
|
||||
"cannot index into a value of type `{}`",
|
||||
base_t);
|
||||
// Try to give some advice about indexing tuples.
|
||||
if let ty::TyTuple(..) = base_t.sty {
|
||||
let mut needs_note = true;
|
||||
// If the index is an integer, we can show the actual
|
||||
// fixed expression:
|
||||
if let hir::ExprLit(ref lit) = idx.node {
|
||||
if let ast::LitKind::Int(i,
|
||||
ast::LitIntType::Unsuffixed) = lit.node {
|
||||
let snip = tcx.sess.codemap().span_to_snippet(base.span);
|
||||
if let Ok(snip) = snip {
|
||||
err.span_suggestion(expr.span,
|
||||
"to access tuple elements, use",
|
||||
format!("{}.{}", snip, i));
|
||||
needs_note = false;
|
||||
}
|
||||
}
|
||||
}
|
||||
if needs_note {
|
||||
err.help("to access tuple elements, use tuple indexing \
|
||||
syntax (e.g. `tuple.0`)");
|
||||
}
|
||||
}
|
||||
err.emit();
|
||||
self.tcx.types.err
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
hir::ExprYield(ref value) => {
|
||||
match self.yield_ty {
|
||||
Some(ty) => {
|
||||
self.check_expr_coercable_to_type(&value, ty);
|
||||
}
|
||||
None => {
|
||||
struct_span_err!(self.tcx.sess, expr.span, E0627,
|
||||
"yield statement outside of generator literal").emit();
|
||||
}
|
||||
}
|
||||
tcx.mk_nil()
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
Reference in New Issue
Block a user