From dfaea9c9677f97656ad75f6bacd78f8f87e1d339 Mon Sep 17 00:00:00 2001 From: Aleksei Latyshev Date: Fri, 25 Dec 2020 14:45:04 +0300 Subject: [PATCH] lint &PathBuf instead of &Path in PTR_ARG - extract get_only_generic_arg_snippet to improve readability --- clippy_dev/src/ra_setup.rs | 4 +-- clippy_lints/src/ptr.rs | 60 ++++++++++++++++++++++++++++---------- tests/ui/ptr_arg.rs | 22 ++++++++++++++ tests/ui/ptr_arg.stderr | 45 +++++++++++++++++++++++----- 4 files changed, 106 insertions(+), 25 deletions(-) diff --git a/clippy_dev/src/ra_setup.rs b/clippy_dev/src/ra_setup.rs index 40bf4a9505a..5f5048e79e7 100644 --- a/clippy_dev/src/ra_setup.rs +++ b/clippy_dev/src/ra_setup.rs @@ -3,7 +3,7 @@ use std::fs; use std::fs::File; use std::io::prelude::*; -use std::path::PathBuf; +use std::path::{Path, PathBuf}; // This module takes an absolute path to a rustc repo and alters the dependencies to point towards // the respective rustc subcrates instead of using extern crate xyz. @@ -44,7 +44,7 @@ pub fn run(rustc_path: Option<&str>) { } fn inject_deps_into_manifest( - rustc_source_dir: &PathBuf, + rustc_source_dir: &Path, manifest_path: &str, cargo_toml: &str, lib_rs: &str, diff --git a/clippy_lints/src/ptr.rs b/clippy_lints/src/ptr.rs index dcb643a28ae..c494a713631 100644 --- a/clippy_lints/src/ptr.rs +++ b/clippy_lints/src/ptr.rs @@ -182,20 +182,6 @@ fn check_fn(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_id: HirId, opt_body_id: if let ty::Ref(_, ty, Mutability::Not) = ty.kind() { if is_type_diagnostic_item(cx, ty, sym::vec_type) { - let mut ty_snippet = None; - if_chain! { - if let TyKind::Path(QPath::Resolved(_, ref path)) = walk_ptrs_hir_ty(arg).kind; - if let Some(&PathSegment{args: Some(ref parameters), ..}) = path.segments.last(); - then { - let types: Vec<_> = parameters.args.iter().filter_map(|arg| match arg { - GenericArg::Type(ty) => Some(ty), - _ => None, - }).collect(); - if types.len() == 1 { - ty_snippet = snippet_opt(cx, types[0].span); - } - } - }; if let Some(spans) = get_spans(cx, opt_body_id, idx, &[("clone", ".to_owned()")]) { span_lint_and_then( cx, @@ -204,7 +190,7 @@ fn check_fn(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_id: HirId, opt_body_id: "writing `&Vec<_>` instead of `&[_]` involves one more reference and cannot be used \ with non-Vec-based slices.", |diag| { - if let Some(ref snippet) = ty_snippet { + if let Some(ref snippet) = get_only_generic_arg_snippet(cx, arg) { diag.span_suggestion( arg.span, "change this to", @@ -247,6 +233,33 @@ fn check_fn(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_id: HirId, opt_body_id: }, ); } + } else if match_type(cx, ty, &paths::PATH_BUF) { + if let Some(spans) = get_spans(cx, opt_body_id, idx, &[("clone", ".to_path_buf()"), ("as_path", "")]) { + span_lint_and_then( + cx, + PTR_ARG, + arg.span, + "writing `&PathBuf` instead of `&Path` involves a new object where a slice will do.", + |diag| { + diag.span_suggestion( + arg.span, + "change this to", + "&Path".into(), + Applicability::Unspecified, + ); + for (clonespan, suggestion) in spans { + diag.span_suggestion_short( + clonespan, + &snippet_opt(cx, clonespan).map_or("change the call to".into(), |x| { + Cow::Owned(format!("change `{}` to", x)) + }), + suggestion.into(), + Applicability::Unspecified, + ); + } + }, + ); + } } else if match_type(cx, ty, &paths::COW) { if_chain! { if let TyKind::Rptr(_, MutTy { ref ty, ..} ) = arg.kind; @@ -309,6 +322,23 @@ fn check_fn(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_id: HirId, opt_body_id: } } +fn get_only_generic_arg_snippet(cx: &LateContext<'_>, arg: &Ty<'_>) -> Option { + if_chain! { + if let TyKind::Path(QPath::Resolved(_, ref path)) = walk_ptrs_hir_ty(arg).kind; + if let Some(&PathSegment{args: Some(ref parameters), ..}) = path.segments.last(); + let types: Vec<_> = parameters.args.iter().filter_map(|arg| match arg { + GenericArg::Type(ty) => Some(ty), + _ => None, + }).collect(); + if types.len() == 1; + then { + snippet_opt(cx, types[0].span) + } else { + None + } + } +} + fn get_rptr_lm<'tcx>(ty: &'tcx Ty<'tcx>) -> Option<(&'tcx Lifetime, Mutability, Span)> { if let TyKind::Rptr(ref lt, ref m) = ty.kind { Some((lt, m.mutbl, ty.span)) diff --git a/tests/ui/ptr_arg.rs b/tests/ui/ptr_arg.rs index 541225e6351..e8854fb73d9 100644 --- a/tests/ui/ptr_arg.rs +++ b/tests/ui/ptr_arg.rs @@ -2,6 +2,7 @@ #![warn(clippy::ptr_arg)] use std::borrow::Cow; +use std::path::PathBuf; fn do_vec(x: &Vec) { //Nothing here @@ -21,6 +22,15 @@ fn do_str_mut(x: &mut String) { //Nothing here either } +fn do_path(x: &PathBuf) { + //Nothing here either +} + +fn do_path_mut(x: &mut PathBuf) { + // no error here + //Nothing here either +} + fn main() {} trait Foo { @@ -55,6 +65,14 @@ fn str_cloned(x: &String) -> String { x.clone() } +fn path_cloned(x: &PathBuf) -> PathBuf { + let a = x.clone(); + let b = x.clone(); + let c = b.clone(); + let d = a.clone().clone().clone(); + x.clone() +} + fn false_positive_capacity(x: &Vec, y: &String) { let a = x.capacity(); let b = y.clone(); @@ -87,10 +105,12 @@ fn do_string(&self) {} // Check that the allow attribute on parameters is honored mod issue_5644 { use std::borrow::Cow; + use std::path::PathBuf; fn allowed( #[allow(clippy::ptr_arg)] _v: &Vec, #[allow(clippy::ptr_arg)] _s: &String, + #[allow(clippy::ptr_arg)] _p: &PathBuf, #[allow(clippy::ptr_arg)] _c: &Cow<[i32]>, ) { } @@ -100,6 +120,7 @@ impl S { fn allowed( #[allow(clippy::ptr_arg)] _v: &Vec, #[allow(clippy::ptr_arg)] _s: &String, + #[allow(clippy::ptr_arg)] _p: &PathBuf, #[allow(clippy::ptr_arg)] _c: &Cow<[i32]>, ) { } @@ -109,6 +130,7 @@ trait T { fn allowed( #[allow(clippy::ptr_arg)] _v: &Vec, #[allow(clippy::ptr_arg)] _s: &String, + #[allow(clippy::ptr_arg)] _p: &PathBuf, #[allow(clippy::ptr_arg)] _c: &Cow<[i32]>, ) { } diff --git a/tests/ui/ptr_arg.stderr b/tests/ui/ptr_arg.stderr index 314f23497f9..70d1b2f5258 100644 --- a/tests/ui/ptr_arg.stderr +++ b/tests/ui/ptr_arg.stderr @@ -1,5 +1,5 @@ error: writing `&Vec<_>` instead of `&[_]` involves one more reference and cannot be used with non-Vec-based slices. - --> $DIR/ptr_arg.rs:6:14 + --> $DIR/ptr_arg.rs:7:14 | LL | fn do_vec(x: &Vec) { | ^^^^^^^^^ help: change this to: `&[i64]` @@ -7,19 +7,25 @@ LL | fn do_vec(x: &Vec) { = note: `-D clippy::ptr-arg` implied by `-D warnings` error: writing `&String` instead of `&str` involves a new object where a slice will do. - --> $DIR/ptr_arg.rs:15:14 + --> $DIR/ptr_arg.rs:16:14 | LL | fn do_str(x: &String) { | ^^^^^^^ help: change this to: `&str` +error: writing `&PathBuf` instead of `&Path` involves a new object where a slice will do. + --> $DIR/ptr_arg.rs:25:15 + | +LL | fn do_path(x: &PathBuf) { + | ^^^^^^^^ help: change this to: `&Path` + error: writing `&Vec<_>` instead of `&[_]` involves one more reference and cannot be used with non-Vec-based slices. - --> $DIR/ptr_arg.rs:28:18 + --> $DIR/ptr_arg.rs:38:18 | LL | fn do_vec(x: &Vec); | ^^^^^^^^^ help: change this to: `&[i64]` error: writing `&Vec<_>` instead of `&[_]` involves one more reference and cannot be used with non-Vec-based slices. - --> $DIR/ptr_arg.rs:41:14 + --> $DIR/ptr_arg.rs:51:14 | LL | fn cloned(x: &Vec) -> Vec { | ^^^^^^^^ @@ -38,7 +44,7 @@ LL | x.to_owned() | error: writing `&String` instead of `&str` involves a new object where a slice will do. - --> $DIR/ptr_arg.rs:50:18 + --> $DIR/ptr_arg.rs:60:18 | LL | fn str_cloned(x: &String) -> String { | ^^^^^^^ @@ -60,8 +66,31 @@ help: change `x.clone()` to LL | x.to_string() | +error: writing `&PathBuf` instead of `&Path` involves a new object where a slice will do. + --> $DIR/ptr_arg.rs:68:19 + | +LL | fn path_cloned(x: &PathBuf) -> PathBuf { + | ^^^^^^^^ + | +help: change this to + | +LL | fn path_cloned(x: &Path) -> PathBuf { + | ^^^^^ +help: change `x.clone()` to + | +LL | let a = x.to_path_buf(); + | ^^^^^^^^^^^^^^^ +help: change `x.clone()` to + | +LL | let b = x.to_path_buf(); + | ^^^^^^^^^^^^^^^ +help: change `x.clone()` to + | +LL | x.to_path_buf() + | + error: writing `&String` instead of `&str` involves a new object where a slice will do. - --> $DIR/ptr_arg.rs:58:44 + --> $DIR/ptr_arg.rs:76:44 | LL | fn false_positive_capacity(x: &Vec, y: &String) { | ^^^^^^^ @@ -80,10 +109,10 @@ LL | let c = y; | ^ error: using a reference to `Cow` is not recommended. - --> $DIR/ptr_arg.rs:72:25 + --> $DIR/ptr_arg.rs:90:25 | LL | fn test_cow_with_ref(c: &Cow<[i32]>) {} | ^^^^^^^^^^^ help: change this to: `&[i32]` -error: aborting due to 7 previous errors +error: aborting due to 9 previous errors -- 2.44.0