use crate::utils::{
- match_def_path, match_qpath, paths, snippet_with_applicability, span_help_and_lint, span_lint_and_sugg,
+ in_macro, match_def_path, match_qpath, paths, snippet, snippet_with_applicability, span_lint_and_help,
+ span_lint_and_sugg, span_lint_and_then,
};
use if_chain::if_chain;
-use rustc::declare_lint_pass;
-use rustc::hir::{BorrowKind, Expr, ExprKind, HirVec, Mutability, QPath};
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
use rustc_errors::Applicability;
-use rustc_session::declare_tool_lint;
+use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability, QPath};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use rustc_span::symbol::sym;
declare_clippy_lint! {
/// **What it does:** Checks for `mem::replace()` on an `Option` with
/// let taken = std::mem::take(&mut text);
/// ```
pub MEM_REPLACE_WITH_DEFAULT,
- nursery,
+ style,
"replacing a value of type `T` with `T::default()` instead of using `std::mem::take`"
}
declare_lint_pass!(MemReplace =>
[MEM_REPLACE_OPTION_WITH_NONE, MEM_REPLACE_WITH_UNINIT, MEM_REPLACE_WITH_DEFAULT]);
-fn check_replace_option_with_none(cx: &LateContext<'_, '_>, expr: &'_ Expr, args: &HirVec<Expr>) {
- if let ExprKind::Path(ref replacement_qpath) = args[1].kind {
+fn check_replace_option_with_none(cx: &LateContext<'_, '_>, src: &Expr<'_>, dest: &Expr<'_>, expr_span: Span) {
+ if let ExprKind::Path(ref replacement_qpath) = src.kind {
// Check that second argument is `Option::None`
if match_qpath(replacement_qpath, &paths::OPTION_NONE) {
// Since this is a late pass (already type-checked),
// `Option`, we do not need to check the first
// argument's type. All that's left is to get
// replacee's path.
- let replaced_path = match args[0].kind {
+ let replaced_path = match dest.kind {
ExprKind::AddrOf(BorrowKind::Ref, Mutability::Mut, ref replaced) => {
if let ExprKind::Path(QPath::Resolved(None, ref replaced_path)) = replaced.kind {
replaced_path
span_lint_and_sugg(
cx,
MEM_REPLACE_OPTION_WITH_NONE,
- expr.span,
+ expr_span,
"replacing an `Option` with `None`",
"consider `Option::take()` instead",
format!(
}
}
-fn check_replace_with_uninit(cx: &LateContext<'_, '_>, expr: &'_ Expr, args: &HirVec<Expr>) {
- if let ExprKind::Call(ref repl_func, ref repl_args) = args[1].kind {
+fn check_replace_with_uninit(cx: &LateContext<'_, '_>, src: &Expr<'_>, expr_span: Span) {
+ if let ExprKind::Call(ref repl_func, ref repl_args) = src.kind {
if_chain! {
if repl_args.is_empty();
if let ExprKind::Path(ref repl_func_qpath) = repl_func.kind;
if let Some(repl_def_id) = cx.tables.qpath_res(repl_func_qpath, repl_func.hir_id).opt_def_id();
then {
- if match_def_path(cx, repl_def_id, &paths::MEM_UNINITIALIZED) {
- span_help_and_lint(
+ if cx.tcx.is_diagnostic_item(sym::mem_uninitialized, repl_def_id) {
+ span_lint_and_help(
cx,
MEM_REPLACE_WITH_UNINIT,
- expr.span,
+ expr_span,
"replacing with `mem::uninitialized()`",
"consider using the `take_mut` crate instead",
);
- } else if match_def_path(cx, repl_def_id, &paths::MEM_ZEROED) &&
- !cx.tables.expr_ty(&args[1]).is_primitive() {
- span_help_and_lint(
+ } else if cx.tcx.is_diagnostic_item(sym::mem_zeroed, repl_def_id) &&
+ !cx.tables.expr_ty(src).is_primitive() {
+ span_lint_and_help(
cx,
MEM_REPLACE_WITH_UNINIT,
- expr.span,
+ expr_span,
"replacing with `mem::zeroed()`",
"consider using a default value or the `take_mut` crate instead",
);
}
}
-fn check_replace_with_default(cx: &LateContext<'_, '_>, expr: &'_ Expr, args: &HirVec<Expr>) {
- if let ExprKind::Call(ref repl_func, ref repl_args) = args[1].kind {
+fn check_replace_with_default(cx: &LateContext<'_, '_>, src: &Expr<'_>, dest: &Expr<'_>, expr_span: Span) {
+ if let ExprKind::Call(ref repl_func, _) = src.kind {
if_chain! {
- if repl_args.is_empty();
+ if !in_external_macro(cx.tcx.sess, expr_span);
if let ExprKind::Path(ref repl_func_qpath) = repl_func.kind;
if let Some(repl_def_id) = cx.tables.qpath_res(repl_func_qpath, repl_func.hir_id).opt_def_id();
if match_def_path(cx, repl_def_id, &paths::DEFAULT_TRAIT_METHOD);
then {
- let mut applicability = Applicability::MachineApplicable;
-
- span_lint_and_sugg(
+ span_lint_and_then(
cx,
MEM_REPLACE_WITH_DEFAULT,
- expr.span,
+ expr_span,
"replacing a value of type `T` with `T::default()` is better expressed using `std::mem::take`",
- "consider using",
- format!(
- "std::mem::take({})",
- snippet_with_applicability(cx, args[0].span, "", &mut applicability)
- ),
- applicability,
+ |db| {
+ if !in_macro(expr_span) {
+ let suggestion = format!("std::mem::take({})", snippet(cx, dest.span, ""));
+
+ db.span_suggestion(
+ expr_span,
+ "consider using",
+ suggestion,
+ Applicability::MachineApplicable
+ );
+ }
+ }
);
}
}
if_chain! {
// Check that `expr` is a call to `mem::replace()`
if let ExprKind::Call(ref func, ref func_args) = expr.kind;
- if func_args.len() == 2;
if let ExprKind::Path(ref func_qpath) = func.kind;
if let Some(def_id) = cx.tables.qpath_res(func_qpath, func.hir_id).opt_def_id();
if match_def_path(cx, def_id, &paths::MEM_REPLACE);
-
+ if let [dest, src] = &**func_args;
then {
- check_replace_option_with_none(cx, expr, &func_args);
- check_replace_with_uninit(cx, expr, &func_args);
- check_replace_with_default(cx, expr, &func_args);
+ check_replace_option_with_none(cx, src, dest, expr.span);
+ check_replace_with_uninit(cx, src, expr.span);
+ check_replace_with_default(cx, src, dest, expr.span);
}
}
}
projects / rust.git / blobdiff