Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 87 insertions, 0 deletions

diff --git a/src/tools/clippy/clippy_lints/src/panic_in_result_fn.rs b/src/tools/clippy/clippy_lints/src/panic_in_result_fn.rs
new file mode 100644
index 000000000..21acf003d
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/panic_in_result_fn.rs
@@ -0,0 +1,87 @@
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::macros::root_macro_call_first_node;
+use clippy_utils::return_ty;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::visitors::expr_visitor_no_bodies;
+use rustc_hir as hir;
+use rustc_hir::intravisit::{FnKind, Visitor};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::{sym, Span};
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for usage of `panic!`, `unimplemented!`, `todo!`, `unreachable!` or assertions in a function of type result.
+    ///
+    /// ### Why is this bad?
+    /// For some codebases, it is desirable for functions of type result to return an error instead of crashing. Hence panicking macros should be avoided.
+    ///
+    /// ### Known problems
+    /// Functions called from a function returning a `Result` may invoke a panicking macro. This is not checked.
+    ///
+    /// ### Example
+    /// ```rust
+    /// fn result_with_panic() -> Result<bool, String>
+    /// {
+    ///     panic!("error");
+    /// }
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// fn result_without_panic() -> Result<bool, String> {
+    ///     Err(String::from("error"))
+    /// }
+    /// ```
+    #[clippy::version = "1.48.0"]
+    pub PANIC_IN_RESULT_FN,
+    restriction,
+    "functions of type `Result<..>` that contain `panic!()`, `todo!()`, `unreachable()`, `unimplemented()` or assertion"
+}
+
+declare_lint_pass!(PanicInResultFn  => [PANIC_IN_RESULT_FN]);
+
+impl<'tcx> LateLintPass<'tcx> for PanicInResultFn {
+    fn check_fn(
+        &mut self,
+        cx: &LateContext<'tcx>,
+        fn_kind: FnKind<'tcx>,
+        _: &'tcx hir::FnDecl<'tcx>,
+        body: &'tcx hir::Body<'tcx>,
+        span: Span,
+        hir_id: hir::HirId,
+    ) {
+        if !matches!(fn_kind, FnKind::Closure) && is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym::Result) {
+            lint_impl_body(cx, span, body);
+        }
+    }
+}
+
+fn lint_impl_body<'tcx>(cx: &LateContext<'tcx>, impl_span: Span, body: &'tcx hir::Body<'tcx>) {
+    let mut panics = Vec::new();
+    expr_visitor_no_bodies(|expr| {
+        let Some(macro_call) = root_macro_call_first_node(cx, expr) else { return true };
+        if matches!(
+            cx.tcx.item_name(macro_call.def_id).as_str(),
+            "unimplemented" | "unreachable" | "panic" | "todo" | "assert" | "assert_eq" | "assert_ne"
+        ) {
+            panics.push(macro_call.span);
+            return false;
+        }
+        true
+    })
+    .visit_expr(&body.value);
+    if !panics.is_empty() {
+        span_lint_and_then(
+            cx,
+            PANIC_IN_RESULT_FN,
+            impl_span,
+            "used `unimplemented!()`, `unreachable!()`, `todo!()`, `panic!()` or assertion in a function that returns `Result`",
+            move |diag| {
+                diag.help(
+                    "`unimplemented!()`, `unreachable!()`, `todo!()`, `panic!()` or assertions should not be used in a function that returns `Result` as `Result` is expected to return an error instead of crashing",
+                );
+                diag.span_note(panics, "return Err() instead of panicking");
+            },
+        );
+    }
+}