-// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-use crate::rustc_errors::Applicability;
-use crate::rustc::hir::*;
-use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use crate::rustc::{declare_tool_lint, lint_array};
-use crate::syntax::ast::LitKind;
-use crate::utils::{is_expn_of, match_def_path, opt_def_id, resolve_node, span_lint, span_lint_and_sugg};
+use crate::utils::{is_expn_of, match_function_call, paths, span_lint, span_lint_and_sugg};
use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::*;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use syntax::ast::LitKind;
-/// **What it does:** Checks for usage of `write!()` / `writeln()!` which can be
-/// replaced with `(e)print!()` / `(e)println!()`
-///
-/// **Why is this bad?** Using `(e)println! is clearer and more concise
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// // this would be clearer as `eprintln!("foo: {:?}", bar);`
-/// writeln!(&mut io::stderr(), "foo: {:?}", bar).unwrap();
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for usage of `write!()` / `writeln()!` which can be
+ /// replaced with `(e)print!()` / `(e)println!()`
+ ///
+ /// **Why is this bad?** Using `(e)println! is clearer and more concise
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # use std::io::Write;
+ /// # let bar = "furchtbar";
+ /// // this would be clearer as `eprintln!("foo: {:?}", bar);`
+ /// writeln!(&mut std::io::stderr(), "foo: {:?}", bar).unwrap();
+ /// ```
pub EXPLICIT_WRITE,
complexity,
"using the `write!()` family of functions instead of the `print!()` family of functions, when using the latter would work"
}
-#[derive(Copy, Clone, Debug)]
-pub struct Pass;
-
-impl LintPass for Pass {
- fn get_lints(&self) -> LintArray {
- lint_array!(EXPLICIT_WRITE)
- }
-}
+declare_lint_pass!(ExplicitWrite => [EXPLICIT_WRITE]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ExplicitWrite {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
if_chain! {
// match call to unwrap
- if let ExprKind::MethodCall(ref unwrap_fun, _, ref unwrap_args) = expr.node;
- if unwrap_fun.ident.name == "unwrap";
+ if let ExprKind::MethodCall(ref unwrap_fun, _, ref unwrap_args) = expr.kind;
+ if unwrap_fun.ident.name == sym!(unwrap);
// match call to write_fmt
- if unwrap_args.len() > 0;
- if let ExprKind::MethodCall(ref write_fun, _, ref write_args) =
- unwrap_args[0].node;
- if write_fun.ident.name == "write_fmt";
+ if !unwrap_args.is_empty();
+ if let ExprKind::MethodCall(ref write_fun, _, write_args) =
+ unwrap_args[0].kind;
+ if write_fun.ident.name == sym!(write_fmt);
// match calls to std::io::stdout() / std::io::stderr ()
- if write_args.len() > 0;
- if let ExprKind::Call(ref dest_fun, _) = write_args[0].node;
- if let ExprKind::Path(ref qpath) = dest_fun.node;
- if let Some(dest_fun_id) =
- opt_def_id(resolve_node(cx, qpath, dest_fun.hir_id));
- if let Some(dest_name) = if match_def_path(cx.tcx, dest_fun_id, &["std", "io", "stdio", "stdout"]) {
+ if !write_args.is_empty();
+ if let Some(dest_name) = if match_function_call(cx, &write_args[0], &paths::STDOUT).is_some() {
Some("stdout")
- } else if match_def_path(cx.tcx, dest_fun_id, &["std", "io", "stdio", "stderr"]) {
+ } else if match_function_call(cx, &write_args[0], &paths::STDERR).is_some() {
Some("stderr")
} else {
None
}
// Extract the output string from the given `write_args`.
-fn write_output_string(write_args: &HirVec<Expr>) -> Option<String> {
+fn write_output_string(write_args: &[Expr<'_>]) -> Option<String> {
if_chain! {
// Obtain the string that should be printed
if write_args.len() > 1;
- if let ExprKind::Call(_, ref output_args) = write_args[1].node;
- if output_args.len() > 0;
- if let ExprKind::AddrOf(_, ref output_string_expr) = output_args[0].node;
- if let ExprKind::Array(ref string_exprs) = output_string_expr.node;
- if string_exprs.len() > 0;
- if let ExprKind::Lit(ref lit) = string_exprs[0].node;
+ if let ExprKind::Call(_, ref output_args) = write_args[1].kind;
+ if !output_args.is_empty();
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref output_string_expr) = output_args[0].kind;
+ if let ExprKind::Array(ref string_exprs) = output_string_expr.kind;
+ // we only want to provide an automatic suggestion for simple (non-format) strings
+ if string_exprs.len() == 1;
+ if let ExprKind::Lit(ref lit) = string_exprs[0].kind;
if let LitKind::Str(ref write_output, _) = lit.node;
then {
return Some(write_output.to_string())
projects / rust.git / blobdiff