Add function name to the non local effect lint

examples/general/non_local_effect_before_error_return/Cargo.toml

@@ -22,6 +22,7 @@ dylint_linting = { path = "../../../utils/linting" }
 
 [dev-dependencies]
 bitflags = "2.4"
+derivative = "2.2.0"
 once_cell = "1.19"
 
 dylint_testing = { path = "../../../utils/testing" }

examples/general/non_local_effect_before_error_return/src/lib.rs

@@ -150,22 +150,21 @@ impl<'tcx> LateLintPass<'tcx> for NonLocalEffectBeforeErrorReturn {
             |path, contributing_calls, span| {
                 // smoelius: The path is from a return to the start block.
                 for (i, &index) in path.iter().enumerate() {
-                    let basic_block = &mir.basic_blocks[index];
-
                     if_chain! {
                         if !contributing_calls.contains(index);
-                        if let Some(call_span) = is_call_with_mut_ref(cx, mir, &path[i..]);
+                        if let Some((func, func_span)) = is_call_with_mut_ref(cx, mir, &path[i..]);
                         then {
                             span_lint_and_then(
                                 cx,
                                 NON_LOCAL_EFFECT_BEFORE_ERROR_RETURN,
-                                call_span,
-                                "call with mutable reference before error return",
+                                func_span,
+                                &format!("call to `{func:?}` with mutable reference before error return"),
                                 error_note(span),
                             );
                         }
                     }
 
+                    let basic_block = &mir.basic_blocks[index];
                     for statement in basic_block.statements.iter().rev() {
                         if let Some(assign_span) = is_deref_assign(statement) {
                             span_lint_and_then(
@@ -204,7 +203,7 @@ fn is_call_with_mut_ref<'tcx>(
     cx: &LateContext<'tcx>,
     mir: &'tcx Body<'tcx>,
     path: &[BasicBlock],
-) -> Option<Span> {
+) -> Option<(&'tcx Operand<'tcx>, Span)> {
     let index = path[0];
     let basic_block = &mir[index];
     let terminator = basic_block.terminator();
@@ -223,7 +222,7 @@ fn is_call_with_mut_ref<'tcx>(
         if locals.iter().any(|local| is_mut_ref_arg(mir, local))
             || constants.iter().any(|constant| is_const_ref(constant));
         then {
-            Some(*fn_span)
+            Some((func, *fn_span))
         } else {
             None
         }

examples/general/non_local_effect_before_error_return/ui/main.rs

@@ -253,3 +253,13 @@ mod downcast {
         Ok(())
     }
 }
+
+use derivative::Derivative;
+
+#[derive(Derivative)]
+#[derivative(Debug)]
+struct Foo {
+    foo: u8,
+    #[derivative(Debug = "ignore")]
+    bar: u8,
+}

examples/general/non_local_effect_before_error_return/ui/main.stderr

@@ -12,7 +12,7 @@ LL |     Err(VarError::NotPresent)
    = note: `-D non-local-effect-before-error-return` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(non_local_effect_before_error_return)]`
 
-error: call with mutable reference before error return
+error: call to `std::vec::Vec::<u32>::push` with mutable reference before error return
   --> $DIR/main.rs:28:8
    |
 LL |     xs.push(0);
@@ -36,7 +36,7 @@ note: error is determined here
 LL |     let _ = var("X")?;
    |             ^^^^^^^^^
 
-error: call with mutable reference before error return
+error: call to `std::vec::Vec::<u32>::push` with mutable reference before error return
   --> $DIR/main.rs:39:8
    |
 LL |     xs.push(0);
@@ -60,7 +60,7 @@ note: error is determined here
 LL |     let result = Err(VarError::NotPresent);
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: call with mutable reference before error return
+error: call to `std::vec::Vec::<u32>::push` with mutable reference before error return
   --> $DIR/main.rs:64:8
    |
 LL |     xs.push(0);
@@ -84,7 +84,7 @@ note: error is determined here
 LL |     match result {
    |     ^^^^^^^^^^^^
 
-error: call with mutable reference before error return
+error: call to `std::vec::Vec::<u32>::push` with mutable reference before error return
   --> $DIR/main.rs:106:16
    |
 LL |             xs.push(0);
@@ -120,7 +120,7 @@ note: error is determined here
 LL |         Err(Error::Two)
    |         ^^^^^^^^^^^^^^^
 
-error: call with mutable reference before error return
+error: call to `bitflags::_::<impl bitflags::Flags>::insert` with mutable reference before error return
   --> $DIR/main.rs:185:15
    |
 LL |         flags.insert(flag);
@@ -132,7 +132,7 @@ note: error is determined here
 LL |             return Err(());
    |                    ^^^^^^^
 
-error: call with mutable reference before error return
+error: call to `std::string::String::push` with mutable reference before error return
   --> $DIR/main.rs:202:11
    |
 LL |         s.push('x');
@@ -144,7 +144,7 @@ note: error is determined here
 LL |         Err(())
    |         ^^^^^^^
 
-error: call with mutable reference before error return
+error: call to `std::process::Command::env::<&str, &str>` with mutable reference before error return
   --> $DIR/main.rs:212:10
    |
 LL |         .env("RUST_LOG", "debug")
@@ -156,5 +156,11 @@ error: assignment to dereference before error return
 LL |         *flag = true;
    |         ^^^^^^^^^^^^
 
-error: aborting due to 14 previous errors
+error: call to `std::fmt::DebugStruct::<'_, '_>::field` with mutable reference before error return
+  --> $DIR/main.rs:261:8
+   |
+LL | struct Foo {
+   |        ^^^
+
+error: aborting due to 15 previous errors