Add #[clippy::print_hir] attribute for debugging

Author: xFrednet

clippy_lints/src/lib.rs

@@ -501,7 +501,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     {
         store.register_early_pass(|| Box::new(utils::internal_lints::ClippyLintsInternal));
         store.register_early_pass(|| Box::new(utils::internal_lints::ProduceIce));
-        store.register_late_pass(|| Box::new(utils::inspector::DeepCodeInspector));
         store.register_late_pass(|| Box::new(utils::internal_lints::CollapsibleCalls));
         store.register_late_pass(|| Box::new(utils::internal_lints::CompilerLintFunctions::new()));
         store.register_late_pass(|| Box::new(utils::internal_lints::IfChainStyle));
@@ -513,6 +512,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         store.register_late_pass(|| Box::new(utils::internal_lints::MsrvAttrImpl));
     }
 
+    store.register_late_pass(|| Box::new(utils::dump_hir::DumpHir));
     store.register_late_pass(|| Box::new(utils::author::Author));
     store.register_late_pass(|| Box::new(await_holding_invalid::AwaitHolding));
     store.register_late_pass(|| Box::new(serde_api::SerdeApi));

clippy_lints/src/utils/dump_hir.rs

@@ -0,0 +1,55 @@
+use clippy_utils::get_attr;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// It formats the attached node with `{:#?}` and writes the result to the
+    /// standard output. This is intended for debugging.
+    ///
+    /// ### Examples
+    /// ```rs
+    /// #[clippy::dump]
+    /// use std::mem;
+    ///
+    /// #[clippy::dump]
+    /// fn foo(input: u32) -> u64 {
+    ///     input as u64
+    /// }
+    /// ```
+    pub DUMP_HIR,
+    internal_warn,
+    "helper to dump info about code"
+}
+
+declare_lint_pass!(DumpHir => [DUMP_HIR]);
+
+impl<'tcx> LateLintPass<'tcx> for DumpHir {
+    fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
+        if has_attr(cx, item.hir_id()) {
+            println!("{item:#?}");
+        }
+    }
+
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
+        if has_attr(cx, expr.hir_id) {
+            println!("{expr:#?}");
+        }
+    }
+
+    fn check_stmt(&mut self, cx: &LateContext<'tcx>, stmt: &'tcx hir::Stmt<'_>) {
+        match stmt.kind {
+            hir::StmtKind::Expr(e) | hir::StmtKind::Semi(e) if has_attr(cx, e.hir_id) => return,
+            _ => {},
+        }
+        if has_attr(cx, stmt.hir_id) {
+            println!("{stmt:#?}");
+        }
+    }
+}
+
+fn has_attr(cx: &LateContext<'_>, hir_id: hir::HirId) -> bool {
+    let attrs = cx.tcx.hir().attrs(hir_id);
+    get_attr(cx.sess(), attrs, "dump").count() > 0
+}