src/tools/clippy/clippy_utils/src/ptr.rs

   1 use crate::source::snippet;
   2 use crate::visitors::{for_each_expr, Descend};
   3 use crate::{path_to_local_id, strip_pat_refs};
   4 use core::ops::ControlFlow;
   5 use rustc_hir::{Body, BodyId, ExprKind, HirId, PatKind};
   6 use rustc_lint::LateContext;
   7 use rustc_span::Span;
   8 use std::borrow::Cow;
   9
  10 pub fn get_spans(
  11     cx: &LateContext<'_>,
  12     opt_body_id: Option<BodyId>,
  13     idx: usize,
  14     replacements: &[(&'static str, &'static str)],
  15 ) -> Option<Vec<(Span, Cow<'static, str>)>> {
  16     if let Some(body) = opt_body_id.map(|id| cx.tcx.hir().body(id)) {
  17         if let PatKind::Binding(_, binding_id, _, _) = strip_pat_refs(body.params[idx].pat).kind {
  18             extract_clone_suggestions(cx, binding_id, replacements, body)
  19         } else {
  20             Some(vec![])
  21         }
  22     } else {
  23         Some(vec![])
  24     }
  25 }
  26
  27 fn extract_clone_suggestions<'tcx>(
  28     cx: &LateContext<'tcx>,
  29     id: HirId,
  30     replace: &[(&'static str, &'static str)],
  31     body: &'tcx Body<'_>,
  32 ) -> Option<Vec<(Span, Cow<'static, str>)>> {
  33     let mut spans = Vec::new();
  34     for_each_expr(body, |e| {
  35         if let ExprKind::MethodCall(seg, recv, [], _) = e.kind
  36             && path_to_local_id(recv, id)
  37         {
  38             if seg.ident.as_str() == "capacity" {
  39                 return ControlFlow::Break(());
  40             }
  41             for &(fn_name, suffix) in replace {
  42                 if seg.ident.as_str() == fn_name {
  43                     spans.push((e.span, snippet(cx, recv.span, "_") + suffix));
  44                     return ControlFlow::Continue(Descend::No);
  45                 }
  46             }
  47         }
  48         ControlFlow::Continue(Descend::Yes)
  49     })
  50     .is_none()
  51     .then_some(spans)
  52 }