use crate::utils::{is_expn_of, match_function_call, paths, span_lint, span_lint_and_sugg};
use if_chain::if_chain;
-use rustc::declare_lint_pass;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc_ast::ast::LitKind;
use rustc_errors::Applicability;
-use rustc_session::declare_tool_lint;
-use syntax::ast::LitKind;
+use rustc_hir::{BorrowKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
declare_clippy_lint! {
/// **What it does:** Checks for usage of `write!()` / `writeln()!` which can be
declare_lint_pass!(ExplicitWrite => [EXPLICIT_WRITE]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ExplicitWrite {
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+impl<'tcx> LateLintPass<'tcx> for ExplicitWrite {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
if_chain! {
// match call to unwrap
- if let ExprKind::MethodCall(ref unwrap_fun, _, ref unwrap_args) = expr.kind;
- if unwrap_fun.ident.name == sym!(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) =
+ 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 !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_function_call(cx, &write_args[0], &paths::STDERR).is_some() {
}
// 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].kind;
- if output_args.len() > 0;
+ 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