add DefId to UnsafetyViolationDetails

this enables consumers to access the function definition that was reported to be unsafe

Author: Emilgardis

compiler/rustc_middle/src/mir/query.rs

@@ -28,7 +28,7 @@ pub enum UnsafetyViolationKind {
 
 #[derive(Copy, Clone, PartialEq, TyEncodable, TyDecodable, HashStable, Debug)]
 pub enum UnsafetyViolationDetails {
-    CallToUnsafeFunction,
+    CallToUnsafeFunction(Option<DefId>),
     UseOfInlineAssembly,
     InitializingTypeWith,
     CastOfPointerToInt,
@@ -39,14 +39,14 @@ pub enum UnsafetyViolationDetails {
     AccessToUnionField,
     MutationOfLayoutConstrainedField,
     BorrowOfLayoutConstrainedField,
-    CallToFunctionWith,
+    CallToFunctionWith(DefId),
 }
 
 impl UnsafetyViolationDetails {
     pub fn description_and_note(&self) -> (&'static str, &'static str) {
         use UnsafetyViolationDetails::*;
         match self {
-            CallToUnsafeFunction => (
+            CallToUnsafeFunction(..) => (
                 "call to unsafe function",
                 "consult the function's documentation for information on how to avoid undefined \
                  behavior",
@@ -97,7 +97,7 @@ impl UnsafetyViolationDetails {
                 "references to fields of layout constrained fields lose the constraints. Coupled \
                  with interior mutability, the field can be changed to invalid values",
             ),
-            CallToFunctionWith => (
+            CallToFunctionWith(..) => (
                 "call to function with `#[target_feature]`",
                 "can only be called if the required target features are available",
             ),

compiler/rustc_mir_transform/src/check_unsafety.rs

@@ -70,15 +70,17 @@ impl<'tcx> Visitor<'tcx> for UnsafetyChecker<'_, 'tcx> {
 
             TerminatorKind::Call { ref func, .. } => {
                 let func_ty = func.ty(self.body, self.tcx);
+                let func_id =
+                    if let ty::FnDef(func_id, _) = func_ty.kind() { Some(func_id) } else { None };
                 let sig = func_ty.fn_sig(self.tcx);
                 if let hir::Unsafety::Unsafe = sig.unsafety() {
                     self.require_unsafe(
                         UnsafetyViolationKind::General,
-                        UnsafetyViolationDetails::CallToUnsafeFunction,
+                        UnsafetyViolationDetails::CallToUnsafeFunction(func_id.copied()),
                     )
                 }
 
-                if let ty::FnDef(func_id, _) = func_ty.kind() {
+                if let Some(func_id) = func_id {
                     self.check_target_features(*func_id);
                 }
             }
@@ -379,7 +381,7 @@ impl<'tcx> UnsafetyChecker<'_, 'tcx> {
         if !callee_features.iter().all(|feature| self_features.contains(feature)) {
             self.require_unsafe(
                 UnsafetyViolationKind::General,
-                UnsafetyViolationDetails::CallToFunctionWith,
+                UnsafetyViolationDetails::CallToFunctionWith(func_did),
             )
         }
     }