src/tools/clippy/clippy_lints/src/panic_unimplemented.rs

   1 use clippy_utils::diagnostics::span_lint;
   2 use clippy_utils::macros::{is_panic, root_macro_call_first_node};
   3 use rustc_hir::Expr;
   4 use rustc_lint::{LateContext, LateLintPass};
   5 use rustc_session::declare_lint_pass;
   6
   7 declare_clippy_lint! {
   8     /// ### What it does
   9     /// Checks for usage of `panic!`.
  10     ///
  11     /// ### Why is this bad?
  12     /// `panic!` will stop the execution of the executable.
  13     ///
  14     /// ### Example
  15     /// ```no_run
  16     /// panic!("even with a good reason");
  17     /// ```
  18     #[clippy::version = "1.40.0"]
  19     pub PANIC,
  20     restriction,
  21     "usage of the `panic!` macro"
  22 }
  23
  24 declare_clippy_lint! {
  25     /// ### What it does
  26     /// Checks for usage of `unimplemented!`.
  27     ///
  28     /// ### Why is this bad?
  29     /// This macro should not be present in production code.
  30     ///
  31     /// ### Example
  32     /// ```no_run
  33     /// unimplemented!();
  34     /// ```
  35     #[clippy::version = "pre 1.29.0"]
  36     pub UNIMPLEMENTED,
  37     restriction,
  38     "`unimplemented!` should not be present in production code"
  39 }
  40
  41 declare_clippy_lint! {
  42     /// ### What it does
  43     /// Checks for usage of `todo!`.
  44     ///
  45     /// ### Why is this bad?
  46     /// The `todo!` macro is often used for unfinished code, and it causes
  47     /// code to panic. It should not be present in production code.
  48     ///
  49     /// ### Example
  50     /// ```no_run
  51     /// todo!();
  52     /// ```
  53     /// Finish the implementation, or consider marking it as explicitly unimplemented.
  54     /// ```no_run
  55     /// unimplemented!();
  56     /// ```
  57     #[clippy::version = "1.40.0"]
  58     pub TODO,
  59     restriction,
  60     "`todo!` should not be present in production code"
  61 }
  62
  63 declare_clippy_lint! {
  64     /// ### What it does
  65     /// Checks for usage of `unreachable!`.
  66     ///
  67     /// ### Why is this bad?
  68     /// This macro can cause code to panic.
  69     ///
  70     /// ### Example
  71     /// ```no_run
  72     /// unreachable!();
  73     /// ```
  74     #[clippy::version = "1.40.0"]
  75     pub UNREACHABLE,
  76     restriction,
  77     "usage of the `unreachable!` macro"
  78 }
  79
  80 declare_lint_pass!(PanicUnimplemented => [UNIMPLEMENTED, UNREACHABLE, TODO, PANIC]);
  81
  82 impl<'tcx> LateLintPass<'tcx> for PanicUnimplemented {
  83     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
  84         let Some(macro_call) = root_macro_call_first_node(cx, expr) else {
  85             return;
  86         };
  87         if is_panic(cx, macro_call.def_id) {
  88             if cx.tcx.hir().is_inside_const_context(expr.hir_id) {
  89                 return;
  90             }
  91
  92             span_lint(
  93                 cx,
  94                 PANIC,
  95                 macro_call.span,
  96                 "`panic` should not be present in production code",
  97             );
  98             return;
  99         }
 100         match cx.tcx.item_name(macro_call.def_id).as_str() {
 101             "todo" => {
 102                 span_lint(
 103                     cx,
 104                     TODO,
 105                     macro_call.span,
 106                     "`todo` should not be present in production code",
 107                 );
 108             },
 109             "unimplemented" => {
 110                 span_lint(
 111                     cx,
 112                     UNIMPLEMENTED,
 113                     macro_call.span,
 114                     "`unimplemented` should not be present in production code",
 115                 );
 116             },
 117             "unreachable" => {
 118                 span_lint(cx, UNREACHABLE, macro_call.span, "usage of the `unreachable!` macro");
 119             },
 120             _ => {},
 121         }
 122     }
 123 }