-use crate::utils::{get_parent_expr, span_lint, span_lint_and_note};
-use if_chain::if_chain;
+use crate::utils::{get_parent_expr, path_to_local, path_to_local_id, span_lint, span_lint_and_note};
use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
-use rustc_hir::{def, BinOpKind, Block, Expr, ExprKind, Guard, HirId, Local, Node, QPath, Stmt, StmtKind};
+use rustc_hir::{BinOpKind, Block, Expr, ExprKind, Guard, HirId, Local, Node, Stmt, StmtKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::hir::map::Map;
use rustc_middle::ty;
// Find a write to a local variable.
match expr.kind {
ExprKind::Assign(ref lhs, ..) | ExprKind::AssignOp(_, ref lhs, _) => {
- if let ExprKind::Path(ref qpath) = lhs.kind {
- if let QPath::Resolved(_, ref path) = *qpath {
- if path.segments.len() == 1 {
- if let def::Res::Local(var) = cx.qpath_res(qpath, lhs.hir_id) {
- let mut visitor = ReadVisitor {
- cx,
- var,
- write_expr: expr,
- last_expr: expr,
- };
- check_for_unsequenced_reads(&mut visitor);
- }
- }
- }
+ if let Some(var) = path_to_local(lhs) {
+ let mut visitor = ReadVisitor {
+ cx,
+ var,
+ write_expr: expr,
+ last_expr: expr,
+ };
+ check_for_unsequenced_reads(&mut visitor);
}
},
_ => {},
match typ.kind() {
ty::FnDef(..) | ty::FnPtr(_) => {
let sig = typ.fn_sig(self.cx.tcx);
- if let ty::Never = self.cx.tcx.erase_late_bound_regions(&sig).output().kind() {
+ if let ty::Never = self.cx.tcx.erase_late_bound_regions(sig).output().kind() {
self.report_diverging_sub_expr(e);
}
},
return;
}
- match expr.kind {
- ExprKind::Path(ref qpath) => {
- if_chain! {
- if let QPath::Resolved(None, ref path) = *qpath;
- if path.segments.len() == 1;
- if let def::Res::Local(local_id) = self.cx.qpath_res(qpath, expr.hir_id);
- if local_id == self.var;
- // Check that this is a read, not a write.
- if !is_in_assignment_position(self.cx, expr);
- then {
- span_lint_and_note(
- self.cx,
- EVAL_ORDER_DEPENDENCE,
- expr.span,
- "unsequenced read of a variable",
- Some(self.write_expr.span),
- "whether read occurs before this write depends on evaluation order"
- );
- }
- }
+ if path_to_local_id(expr, self.var) {
+ // Check that this is a read, not a write.
+ if !is_in_assignment_position(self.cx, expr) {
+ span_lint_and_note(
+ self.cx,
+ EVAL_ORDER_DEPENDENCE,
+ expr.span,
+ "unsequenced read of a variable",
+ Some(self.write_expr.span),
+ "whether read occurs before this write depends on evaluation order",
+ );
}
+ }
+ match expr.kind {
// We're about to descend a closure. Since we don't know when (or
// if) the closure will be evaluated, any reads in it might not
// occur here (or ever). Like above, bail to avoid false positives.