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Auto merge of #6278 - ThibsG:DerefAddrOf, r=llogiq

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Fix bad suggestions for `deref_addrof` and `try_err` lints

Fix bad suggestions when in macro expansion for `deref_addrof` and `try_err` lints.

Fixes: #6234
Fixes: #6242
Fixes: #6237

changelog: none

r? `@llogiq`
This commit is contained in:
bors 2020-11-09 05:25:04 +00:00
commit d212c382c3
8 changed files with 207 additions and 15 deletions
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37
clippy_lints/src/reference.rs
View file

@ -1,9 +1,10 @@
use crate::utils::{in_macro, snippet_with_applicability, span_lint_and_sugg};
use crate::utils::{in_macro, snippet_opt, snippet_with_applicability, span_lint_and_sugg};
use if_chain::if_chain;
use rustc_ast::ast::{Expr, ExprKind, UnOp};
use rustc_ast::ast::{Expr, ExprKind, Mutability, UnOp};
use rustc_errors::Applicability;
use rustc_lint::{EarlyContext, EarlyLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::BytePos;
declare_clippy_lint! {
/// **What it does:** Checks for usage of `*&` and `*&mut` in expressions.
@ -42,17 +43,45 @@ impl EarlyLintPass for DerefAddrOf {
fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &Expr) {
if_chain! {
if let ExprKind::Unary(UnOp::Deref, ref deref_target) = e.kind;
if let ExprKind::AddrOf(_, _, ref addrof_target) = without_parens(deref_target).kind;
if let ExprKind::AddrOf(_, ref mutability, ref addrof_target) = without_parens(deref_target).kind;
if !in_macro(addrof_target.span);
then {
let mut applicability = Applicability::MachineApplicable;
let sugg = if e.span.from_expansion() {
if let Ok(macro_source) = cx.sess.source_map().span_to_snippet(e.span) {
// Remove leading whitespace from the given span
// e.g: ` $visitor` turns into `$visitor`
let trim_leading_whitespaces = |span| {
snippet_opt(cx, span).and_then(|snip| {
#[allow(clippy::cast_possible_truncation)]
snip.find(|c: char| !c.is_whitespace()).map(|pos| {
span.lo() + BytePos(pos as u32)
})
}).map_or(span, |start_no_whitespace| e.span.with_lo(start_no_whitespace))
};
let rpos = if *mutability == Mutability::Mut {
macro_source.rfind("mut").expect("already checked this is a mutable reference") + "mut".len()
} else {
macro_source.rfind('&').expect("already checked this is a reference") + "&".len()
};
#[allow(clippy::cast_possible_truncation)]
let span_after_ref = e.span.with_lo(BytePos(e.span.lo().0 + rpos as u32));
let span = trim_leading_whitespaces(span_after_ref);
snippet_with_applicability(cx, span, "_", &mut applicability)
} else {
snippet_with_applicability(cx, e.span, "_", &mut applicability)
}
} else {
snippet_with_applicability(cx, addrof_target.span, "_", &mut applicability)
}.to_string();
span_lint_and_sugg(
cx,
DEREF_ADDROF,
e.span,
"immediately dereferencing a reference",
"try this",
format!("{}", snippet_with_applicability(cx, addrof_target.span, "_", &mut applicability)),
sugg,
applicability,
);
}

9
clippy_lints/src/try_err.rs
View file

@ -1,6 +1,6 @@
use crate::utils::{
is_type_diagnostic_item, match_def_path, match_qpath, paths, snippet, snippet_with_macro_callsite,
span_lint_and_sugg,
differing_macro_contexts, in_macro, is_type_diagnostic_item, match_def_path, match_qpath, paths, snippet,
snippet_with_macro_callsite, span_lint_and_sugg,
};
use if_chain::if_chain;
use rustc_errors::Applicability;
@ -92,8 +92,11 @@ impl<'tcx> LateLintPass<'tcx> for TryErr {
};
let expr_err_ty = cx.typeck_results().expr_ty(err_arg);
let differing_contexts = differing_macro_contexts(expr.span, err_arg.span);
let origin_snippet = if err_arg.span.from_expansion() {
let origin_snippet = if in_macro(expr.span) && in_macro(err_arg.span) && differing_contexts {
snippet(cx, err_arg.span.ctxt().outer_expn_data().call_site, "_")
} else if err_arg.span.from_expansion() && !in_macro(expr.span) {
snippet_with_macro_callsite(cx, err_arg.span, "_")
} else {
snippet(cx, err_arg.span, "_")