use super::{contains_return, BIND_INSTEAD_OF_MAP};
use clippy_utils::diagnostics::{multispan_sugg_with_applicability, span_lint_and_sugg, span_lint_and_then};
use clippy_utils::source::{snippet, snippet_with_macro_callsite};
-use clippy_utils::ty::match_type;
-use clippy_utils::{in_macro, match_qpath, method_calls, paths, remove_blocks, visitors::find_all_ret_expressions};
+use clippy_utils::{peel_blocks, visitors::find_all_ret_expressions};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir as hir;
+use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
+use rustc_hir::{LangItem, QPath};
use rustc_lint::LateContext;
+use rustc_middle::ty::DefIdTree;
use rustc_span::Span;
pub(crate) struct OptionAndThenSome;
impl BindInsteadOfMap for OptionAndThenSome {
- const TYPE_NAME: &'static str = "Option";
- const TYPE_QPATH: &'static [&'static str] = &paths::OPTION;
-
+ const VARIANT_LANG_ITEM: LangItem = LangItem::OptionSome;
const BAD_METHOD_NAME: &'static str = "and_then";
- const BAD_VARIANT_NAME: &'static str = "Some";
- const BAD_VARIANT_QPATH: &'static [&'static str] = &paths::OPTION_SOME;
-
const GOOD_METHOD_NAME: &'static str = "map";
}
pub(crate) struct ResultAndThenOk;
impl BindInsteadOfMap for ResultAndThenOk {
- const TYPE_NAME: &'static str = "Result";
- const TYPE_QPATH: &'static [&'static str] = &paths::RESULT;
-
+ const VARIANT_LANG_ITEM: LangItem = LangItem::ResultOk;
const BAD_METHOD_NAME: &'static str = "and_then";
- const BAD_VARIANT_NAME: &'static str = "Ok";
- const BAD_VARIANT_QPATH: &'static [&'static str] = &paths::RESULT_OK;
-
const GOOD_METHOD_NAME: &'static str = "map";
}
pub(crate) struct ResultOrElseErrInfo;
impl BindInsteadOfMap for ResultOrElseErrInfo {
- const TYPE_NAME: &'static str = "Result";
- const TYPE_QPATH: &'static [&'static str] = &paths::RESULT;
-
+ const VARIANT_LANG_ITEM: LangItem = LangItem::ResultErr;
const BAD_METHOD_NAME: &'static str = "or_else";
- const BAD_VARIANT_NAME: &'static str = "Err";
- const BAD_VARIANT_QPATH: &'static [&'static str] = &paths::RESULT_ERR;
-
const GOOD_METHOD_NAME: &'static str = "map_err";
}
pub(crate) trait BindInsteadOfMap {
- const TYPE_NAME: &'static str;
- const TYPE_QPATH: &'static [&'static str];
-
+ const VARIANT_LANG_ITEM: LangItem;
const BAD_METHOD_NAME: &'static str;
- const BAD_VARIANT_NAME: &'static str;
- const BAD_VARIANT_QPATH: &'static [&'static str];
-
const GOOD_METHOD_NAME: &'static str;
- fn no_op_msg() -> String {
- format!(
+ fn no_op_msg(cx: &LateContext<'_>) -> Option<String> {
+ let variant_id = cx.tcx.lang_items().require(Self::VARIANT_LANG_ITEM).ok()?;
+ let item_id = cx.tcx.parent(variant_id)?;
+ Some(format!(
"using `{}.{}({})`, which is a no-op",
- Self::TYPE_NAME,
+ cx.tcx.item_name(item_id),
Self::BAD_METHOD_NAME,
- Self::BAD_VARIANT_NAME
- )
+ cx.tcx.item_name(variant_id),
+ ))
}
- fn lint_msg() -> String {
- format!(
+ fn lint_msg(cx: &LateContext<'_>) -> Option<String> {
+ let variant_id = cx.tcx.lang_items().require(Self::VARIANT_LANG_ITEM).ok()?;
+ let item_id = cx.tcx.parent(variant_id)?;
+ Some(format!(
"using `{}.{}(|x| {}(y))`, which is more succinctly expressed as `{}(|x| y)`",
- Self::TYPE_NAME,
+ cx.tcx.item_name(item_id),
Self::BAD_METHOD_NAME,
- Self::BAD_VARIANT_NAME,
+ cx.tcx.item_name(variant_id),
Self::GOOD_METHOD_NAME
- )
+ ))
}
fn lint_closure_autofixable(
cx: &LateContext<'_>,
expr: &hir::Expr<'_>,
- args: &[hir::Expr<'_>],
+ recv: &hir::Expr<'_>,
closure_expr: &hir::Expr<'_>,
closure_args_span: Span,
) -> bool {
if_chain! {
- if let hir::ExprKind::Call(ref some_expr, ref some_args) = closure_expr.kind;
- if let hir::ExprKind::Path(ref qpath) = some_expr.kind;
- if match_qpath(qpath, Self::BAD_VARIANT_QPATH);
- if some_args.len() == 1;
+ if let hir::ExprKind::Call(some_expr, [inner_expr]) = closure_expr.kind;
+ if let hir::ExprKind::Path(QPath::Resolved(_, path)) = some_expr.kind;
+ if Self::is_variant(cx, path.res);
+ if !contains_return(inner_expr);
+ if let Some(msg) = Self::lint_msg(cx);
then {
- let inner_expr = &some_args[0];
-
- if contains_return(inner_expr) {
- return false;
- }
-
let some_inner_snip = if inner_expr.span.from_expansion() {
snippet_with_macro_callsite(cx, inner_expr.span, "_")
} else {
};
let closure_args_snip = snippet(cx, closure_args_span, "..");
- let option_snip = snippet(cx, args[0].span, "..");
+ let option_snip = snippet(cx, recv.span, "..");
let note = format!("{}.{}({} {})", option_snip, Self::GOOD_METHOD_NAME, closure_args_snip, some_inner_snip);
span_lint_and_sugg(
cx,
BIND_INSTEAD_OF_MAP,
expr.span,
- Self::lint_msg().as_ref(),
+ &msg,
"try this",
note,
Applicability::MachineApplicable,
let mut suggs = Vec::new();
let can_sugg: bool = find_all_ret_expressions(cx, closure_expr, |ret_expr| {
if_chain! {
- if !in_macro(ret_expr.span);
- if let hir::ExprKind::Call(ref func_path, ref args) = ret_expr.kind;
- if let hir::ExprKind::Path(ref qpath) = func_path.kind;
- if match_qpath(qpath, Self::BAD_VARIANT_QPATH);
- if args.len() == 1;
- if !contains_return(&args[0]);
+ if !ret_expr.span.from_expansion();
+ if let hir::ExprKind::Call(func_path, [arg]) = ret_expr.kind;
+ if let hir::ExprKind::Path(QPath::Resolved(_, path)) = func_path.kind;
+ if Self::is_variant(cx, path.res);
+ if !contains_return(arg);
then {
- suggs.push((ret_expr.span, args[0].span.source_callsite()));
+ suggs.push((ret_expr.span, arg.span.source_callsite()));
true
} else {
false
}
}
});
-
- if can_sugg {
- span_lint_and_then(cx, BIND_INSTEAD_OF_MAP, expr.span, Self::lint_msg().as_ref(), |diag| {
- multispan_sugg_with_applicability(
- diag,
- "try this",
- Applicability::MachineApplicable,
- std::iter::once((*method_calls(expr, 1).2.get(0).unwrap(), Self::GOOD_METHOD_NAME.into())).chain(
- suggs
- .into_iter()
- .map(|(span1, span2)| (span1, snippet(cx, span2, "_").into())),
- ),
- )
- });
- }
- can_sugg
+ let (span, msg) = if_chain! {
+ if can_sugg;
+ if let hir::ExprKind::MethodCall(_, span, ..) = expr.kind;
+ if let Some(msg) = Self::lint_msg(cx);
+ then { (span, msg) } else { return false; }
+ };
+ span_lint_and_then(cx, BIND_INSTEAD_OF_MAP, expr.span, &msg, |diag| {
+ multispan_sugg_with_applicability(
+ diag,
+ "try this",
+ Applicability::MachineApplicable,
+ std::iter::once((span, Self::GOOD_METHOD_NAME.into())).chain(
+ suggs
+ .into_iter()
+ .map(|(span1, span2)| (span1, snippet(cx, span2, "_").into())),
+ ),
+ );
+ });
+ true
}
/// Lint use of `_.and_then(|x| Some(y))` for `Option`s
- fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) -> bool {
- if !match_type(cx, cx.typeck_results().expr_ty(&args[0]), Self::TYPE_QPATH) {
- return false;
+ fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>, arg: &hir::Expr<'_>) -> bool {
+ if_chain! {
+ if let Some(adt) = cx.typeck_results().expr_ty(recv).ty_adt_def();
+ if let Ok(vid) = cx.tcx.lang_items().require(Self::VARIANT_LANG_ITEM);
+ if Some(adt.did) == cx.tcx.parent(vid);
+ then {} else { return false; }
}
- match args[1].kind {
+ match arg.kind {
hir::ExprKind::Closure(_, _, body_id, closure_args_span, _) => {
let closure_body = cx.tcx.hir().body(body_id);
- let closure_expr = remove_blocks(&closure_body.value);
+ let closure_expr = peel_blocks(&closure_body.value);
- if Self::lint_closure_autofixable(cx, expr, args, closure_expr, closure_args_span) {
+ if Self::lint_closure_autofixable(cx, expr, recv, closure_expr, closure_args_span) {
true
} else {
Self::lint_closure(cx, expr, closure_expr)
}
},
// `_.and_then(Some)` case, which is no-op.
- hir::ExprKind::Path(ref qpath) if match_qpath(qpath, Self::BAD_VARIANT_QPATH) => {
- span_lint_and_sugg(
- cx,
- BIND_INSTEAD_OF_MAP,
- expr.span,
- Self::no_op_msg().as_ref(),
- "use the expression directly",
- snippet(cx, args[0].span, "..").into(),
- Applicability::MachineApplicable,
- );
+ hir::ExprKind::Path(QPath::Resolved(_, path)) if Self::is_variant(cx, path.res) => {
+ if let Some(msg) = Self::no_op_msg(cx) {
+ span_lint_and_sugg(
+ cx,
+ BIND_INSTEAD_OF_MAP,
+ expr.span,
+ &msg,
+ "use the expression directly",
+ snippet(cx, recv.span, "..").into(),
+ Applicability::MachineApplicable,
+ );
+ }
true
},
_ => false,
}
}
+
+ fn is_variant(cx: &LateContext<'_>, res: Res) -> bool {
+ if let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Fn), id) = res {
+ if let Ok(variant_id) = cx.tcx.lang_items().require(Self::VARIANT_LANG_ITEM) {
+ return cx.tcx.parent(id) == Some(variant_id);
+ }
+ }
+ false
+ }
}
projects / rust.git / blobdiff