From 2a7d5599706f127c1ebe6e5f992f9245d7f09b8a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9o=20Lanteri=20Thauvin?= <leseulartichaut@gmail.com>
Date: Mon, 26 Dec 2022 18:49:19 +0100
Subject: [PATCH] Don't trim path for `unsafe_op_in_unsafe_fn` lints

---
 .../rustc_mir_build/src/check_unsafety.rs     | 23 +++++++++++--------
 src/test/ui/unsafe/auxiliary/issue-106126.rs  |  9 ++++++++
 .../ui/unsafe/issue-106126-good-path-bug.rs   | 12 ++++++++++
 3 files changed, 34 insertions(+), 10 deletions(-)
 create mode 100644 src/test/ui/unsafe/auxiliary/issue-106126.rs
 create mode 100644 src/test/ui/unsafe/issue-106126-good-path-bug.rs

diff --git a/compiler/rustc_mir_build/src/check_unsafety.rs b/compiler/rustc_mir_build/src/check_unsafety.rs
index 3c311729a52aa..03a7f2d70faeb 100644
--- a/compiler/rustc_mir_build/src/check_unsafety.rs
+++ b/compiler/rustc_mir_build/src/check_unsafety.rs
@@ -5,6 +5,7 @@ use rustc_middle::thir::visit::{self, Visitor};
 use rustc_hir as hir;
 use rustc_middle::mir::BorrowKind;
 use rustc_middle::thir::*;
+use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt};
 use rustc_session::lint::builtin::{UNSAFE_OP_IN_UNSAFE_FN, UNUSED_UNSAFE};
 use rustc_session::lint::Level;
@@ -524,17 +525,19 @@ impl UnsafeOpKind {
         hir_id: hir::HirId,
         span: Span,
     ) {
+        // FIXME: ideally we would want to trim the def paths, but this is not
+        // feasible with the current lint emission API (see issue #106126).
         match self {
-            CallToUnsafeFunction(did) if did.is_some() => tcx.emit_spanned_lint(
+            CallToUnsafeFunction(Some(did)) => tcx.emit_spanned_lint(
                 UNSAFE_OP_IN_UNSAFE_FN,
                 hir_id,
                 span,
                 UnsafeOpInUnsafeFnCallToUnsafeFunctionRequiresUnsafe {
                     span,
-                    function: &tcx.def_path_str(did.unwrap()),
+                    function: &with_no_trimmed_paths!(tcx.def_path_str(*did)),
                 },
             ),
-            CallToUnsafeFunction(..) => tcx.emit_spanned_lint(
+            CallToUnsafeFunction(None) => tcx.emit_spanned_lint(
                 UNSAFE_OP_IN_UNSAFE_FN,
                 hir_id,
                 span,
@@ -594,7 +597,7 @@ impl UnsafeOpKind {
                 span,
                 UnsafeOpInUnsafeFnCallToFunctionWithRequiresUnsafe {
                     span,
-                    function: &tcx.def_path_str(*did),
+                    function: &with_no_trimmed_paths!(tcx.def_path_str(*did)),
                 },
             ),
         }
@@ -607,24 +610,24 @@ impl UnsafeOpKind {
         unsafe_op_in_unsafe_fn_allowed: bool,
     ) {
         match self {
-            CallToUnsafeFunction(did) if did.is_some() && unsafe_op_in_unsafe_fn_allowed => {
+            CallToUnsafeFunction(Some(did)) if unsafe_op_in_unsafe_fn_allowed => {
                 tcx.sess.emit_err(CallToUnsafeFunctionRequiresUnsafeUnsafeOpInUnsafeFnAllowed {
                     span,
-                    function: &tcx.def_path_str(did.unwrap()),
+                    function: &tcx.def_path_str(*did),
                 });
             }
-            CallToUnsafeFunction(did) if did.is_some() => {
+            CallToUnsafeFunction(Some(did)) => {
                 tcx.sess.emit_err(CallToUnsafeFunctionRequiresUnsafe {
                     span,
-                    function: &tcx.def_path_str(did.unwrap()),
+                    function: &tcx.def_path_str(*did),
                 });
             }
-            CallToUnsafeFunction(..) if unsafe_op_in_unsafe_fn_allowed => {
+            CallToUnsafeFunction(None) if unsafe_op_in_unsafe_fn_allowed => {
                 tcx.sess.emit_err(
                     CallToUnsafeFunctionRequiresUnsafeNamelessUnsafeOpInUnsafeFnAllowed { span },
                 );
             }
-            CallToUnsafeFunction(..) => {
+            CallToUnsafeFunction(None) => {
                 tcx.sess.emit_err(CallToUnsafeFunctionRequiresUnsafeNameless { span });
             }
             UseOfInlineAssembly if unsafe_op_in_unsafe_fn_allowed => {
diff --git a/src/test/ui/unsafe/auxiliary/issue-106126.rs b/src/test/ui/unsafe/auxiliary/issue-106126.rs
new file mode 100644
index 0000000000000..091a3edb756ad
--- /dev/null
+++ b/src/test/ui/unsafe/auxiliary/issue-106126.rs
@@ -0,0 +1,9 @@
+#[macro_export]
+macro_rules! foo {
+    () => {
+        unsafe fn __unsf() {}
+        unsafe fn __foo() {
+            __unsf();
+        }
+    };
+}
diff --git a/src/test/ui/unsafe/issue-106126-good-path-bug.rs b/src/test/ui/unsafe/issue-106126-good-path-bug.rs
new file mode 100644
index 0000000000000..93f478ee35802
--- /dev/null
+++ b/src/test/ui/unsafe/issue-106126-good-path-bug.rs
@@ -0,0 +1,12 @@
+// Regression test for #106126.
+// check-pass
+// aux-build:issue-106126.rs
+
+#![deny(unsafe_op_in_unsafe_fn)]
+
+#[macro_use]
+extern crate issue_106126;
+
+foo!();
+
+fn main() {}