rustc_lint: only query `typeck_tables_of` when a lint needs it.

[rust.git] / clippy_lints / src / indexing_slicing.rs

diff --git a/clippy_lints/src/indexing_slicing.rs b/clippy_lints/src/indexing_slicing.rs
index 65fc29a131f4985b21757909b14f6fc626d5f3cf..c5e4abc94a8a669e9962a6715f3e1279dcd54474 100644 (file)
--- a/clippy_lints/src/indexing_slicing.rs
+++ b/clippy_lints/src/indexing_slicing.rs
@@ -1,14 +1,12 @@
 //! lint on indexing and slicing operations
 
 use crate::consts::{constant, Constant};
-use crate::utils;
-use crate::utils::higher;
-use crate::utils::higher::Range;
-use rustc::ty;
-use rustc_hir::*;
+use crate::utils::{higher, span_lint, span_lint_and_help};
+use rustc_ast::ast::RangeLimits;
+use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
-use syntax::ast::RangeLimits;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for out of bounds array indexing with a constant
@@ -90,17 +88,21 @@
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IndexingSlicing {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
         if let ExprKind::Index(ref array, ref index) = &expr.kind {
-            let ty = cx.tables.expr_ty(array);
+            let ty = cx.tables().expr_ty(array);
             if let Some(range) = higher::range(cx, index) {
                 // Ranged indexes, i.e., &x[n..m], &x[n..], &x[..n] and &x[..]
                 if let ty::Array(_, s) = ty.kind {
-                    let size: u128 = s.eval_usize(cx.tcx, cx.param_env).into();
+                    let size: u128 = if let Some(size) = s.try_eval_usize(cx.tcx, cx.param_env) {
+                        size.into()
+                    } else {
+                        return;
+                    };
 
                     let const_range = to_const_range(cx, range, size);
 
                     if let (Some(start), _) = const_range {
                         if start > size {
-                            utils::span_lint(
+                            span_lint(
                                 cx,
                                 OUT_OF_BOUNDS_INDEXING,
                                 range.start.map_or(expr.span, |start| start.span),
@@ -112,7 +114,7 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
 
                     if let (_, Some(end)) = const_range {
                         if end > size {
-                            utils::span_lint(
+                            span_lint(
                                 cx,
                                 OUT_OF_BOUNDS_INDEXING,
                                 range.end.map_or(expr.span, |end| end.span),
@@ -136,22 +138,23 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
                     (None, None) => return, // [..] is ok.
                 };
 
-                utils::span_help_and_lint(cx, INDEXING_SLICING, expr.span, "slicing may panic.", help_msg);
+                span_lint_and_help(cx, INDEXING_SLICING, expr.span, "slicing may panic.", None, help_msg);
             } else {
                 // Catchall non-range index, i.e., [n] or [n << m]
                 if let ty::Array(..) = ty.kind {
                     // Index is a constant uint.
-                    if let Some(..) = constant(cx, cx.tables, index) {
+                    if let Some(..) = constant(cx, cx.tables(), index) {
                         // Let rustc's `const_err` lint handle constant `usize` indexing on arrays.
                         return;
                     }
                 }
 
-                utils::span_help_and_lint(
+                span_lint_and_help(
                     cx,
                     INDEXING_SLICING,
                     expr.span,
                     "indexing may panic.",
+                    None,
                     "Consider using `.get(n)` or `.get_mut(n)` instead",
                 );
             }
@@ -163,17 +166,17 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
 /// the range. If the start or end is not constant, None is returned.
 fn to_const_range<'a, 'tcx>(
     cx: &LateContext<'a, 'tcx>,
-    range: Range<'_>,
+    range: higher::Range<'_>,
     array_size: u128,
 ) -> (Option<u128>, Option<u128>) {
-    let s = range.start.map(|expr| constant(cx, cx.tables, expr).map(|(c, _)| c));
+    let s = range.start.map(|expr| constant(cx, cx.tables(), expr).map(|(c, _)| c));
     let start = match s {
         Some(Some(Constant::Int(x))) => Some(x),
         Some(_) => None,
         None => Some(0),
     };
 
-    let e = range.end.map(|expr| constant(cx, cx.tables, expr).map(|(c, _)| c));
+    let e = range.end.map(|expr| constant(cx, cx.tables(), expr).map(|(c, _)| c));
     let end = match e {
         Some(Some(Constant::Int(x))) => {
             if range.limits == RangeLimits::Closed {