Detect missing ; that parses as function call

compiler/rustc_hir_typeck/src/callee.rs

@@ -645,18 +645,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 self.typeck_results.borrow().qpath_res(qpath, callee_expr.hir_id)
             }
             hir::ExprKind::Call(ref inner_callee, _) => {
-                // If the call spans more than one line and the callee kind is
-                // itself another `ExprCall`, that's a clue that we might just be
-                // missing a semicolon (Issue #51055)
-                let call_is_multiline = self.tcx.sess.source_map().is_multiline(call_expr.span);
-                if call_is_multiline {
-                    err.span_suggestion(
-                        callee_expr.span.shrink_to_hi(),
-                        "consider using a semicolon here",
-                        ";",
-                        Applicability::MaybeIncorrect,
-                    );
-                }
                 if let hir::ExprKind::Path(ref inner_qpath) = inner_callee.kind {
                     inner_callee_path = Some(inner_qpath);
                     self.typeck_results.borrow().qpath_res(inner_qpath, inner_callee.hir_id)
@@ -668,6 +656,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
 
         if !self.maybe_suggest_bad_array_definition(&mut err, call_expr, callee_expr) {
+            // If the call spans more than one line and the callee kind is
+            // itself another `ExprCall`, that's a clue that we might just be
+            // missing a semicolon (#51055, #106515).
+            let call_is_multiline = self
+                .tcx
+                .sess
+                .source_map()
+                .is_multiline(call_expr.span.with_lo(callee_expr.span.hi()))
+                && call_expr.span.ctxt() == callee_expr.span.ctxt();
+            if call_is_multiline {
+                err.span_suggestion(
+                    callee_expr.span.shrink_to_hi(),
+                    "consider using a semicolon here to finish the statement",
+                    ";",
+                    Applicability::MaybeIncorrect,
+                );
+            }
             if let Some((maybe_def, output_ty, _)) = self.extract_callable_info(callee_ty)
                 && !self.type_is_sized_modulo_regions(self.param_env, output_ty)
             {

tests/ui/suggestions/issue-51055-missing-semicolon-between-call-and-tuple.stderr

@@ -5,7 +5,7 @@ LL |   fn vindictive() -> bool { true }
    |   ----------------------- `vindictive` defined here returns `bool`
 ...
 LL |       vindictive()
-   |       -^^^^^^^^^^^- help: consider using a semicolon here: `;`
+   |       -^^^^^^^^^^^- help: consider using a semicolon here to finish the statement: `;`
    |  _____|
    | |
 LL | |     (1, 2)

tests/ui/suggestions/missing-semicolon.fixed

@@ -0,0 +1,38 @@
+// run-rustfix
+#![allow(dead_code, unused_variables, path_statements)]
+fn a() {
+    let x = 5;
+    let y = x; //~ ERROR expected function
+    (); //~ ERROR expected `;`, found `}`
+}
+
+fn b() {
+    let x = 5;
+    let y = x; //~ ERROR expected function
+    ();
+}
+fn c() {
+    let x = 5;
+    x; //~ ERROR expected function
+    ()
+}
+fn d() { // ok
+    let x = || ();
+    x
+    ()
+}
+fn e() { // ok
+    let x = || ();
+    x
+    ();
+}
+fn f()
+ {
+    let y = 5; //~ ERROR expected function
+    (); //~ ERROR expected `;`, found `}`
+}
+fn g() {
+    5; //~ ERROR expected function
+    ();
+}
+fn main() {}

tests/ui/suggestions/missing-semicolon.rs

@@ -0,0 +1,38 @@
+// run-rustfix
+#![allow(dead_code, unused_variables, path_statements)]
+fn a() {
+    let x = 5;
+    let y = x //~ ERROR expected function
+    () //~ ERROR expected `;`, found `}`
+}
+
+fn b() {
+    let x = 5;
+    let y = x //~ ERROR expected function
+    ();
+}
+fn c() {
+    let x = 5;
+    x //~ ERROR expected function
+    ()
+}
+fn d() { // ok
+    let x = || ();
+    x
+    ()
+}
+fn e() { // ok
+    let x = || ();
+    x
+    ();
+}
+fn f()
+ {
+    let y = 5 //~ ERROR expected function
+    () //~ ERROR expected `;`, found `}`
+}
+fn g() {
+    5 //~ ERROR expected function
+    ();
+}
+fn main() {}

tests/ui/suggestions/missing-semicolon.stderr

@@ -0,0 +1,75 @@
+error: expected `;`, found `}`
+  --> $DIR/missing-semicolon.rs:6:7
+   |
+LL |     ()
+   |       ^ help: add `;` here
+LL | }
+   | - unexpected token
+
+error: expected `;`, found `}`
+  --> $DIR/missing-semicolon.rs:32:7
+   |
+LL |     ()
+   |       ^ help: add `;` here
+LL | }
+   | - unexpected token
+
+error[E0618]: expected function, found `{integer}`
+  --> $DIR/missing-semicolon.rs:5:13
+   |
+LL |       let x = 5;
+   |           - `x` has type `{integer}`
+LL |       let y = x
+   |               ^- help: consider using a semicolon here to finish the statement: `;`
+   |  _____________|
+   | |
+LL | |     ()
+   | |______- call expression requires function
+
+error[E0618]: expected function, found `{integer}`
+  --> $DIR/missing-semicolon.rs:11:13
+   |
+LL |       let x = 5;
+   |           - `x` has type `{integer}`
+LL |       let y = x
+   |               ^- help: consider using a semicolon here to finish the statement: `;`
+   |  _____________|
+   | |
+LL | |     ();
+   | |______- call expression requires function
+
+error[E0618]: expected function, found `{integer}`
+  --> $DIR/missing-semicolon.rs:16:5
+   |
+LL |       let x = 5;
+   |           - `x` has type `{integer}`
+LL |       x
+   |       ^- help: consider using a semicolon here to finish the statement: `;`
+   |  _____|
+   | |
+LL | |     ()
+   | |______- call expression requires function
+
+error[E0618]: expected function, found `{integer}`
+  --> $DIR/missing-semicolon.rs:31:13
+   |
+LL |       let y = 5
+   |               ^- help: consider using a semicolon here to finish the statement: `;`
+   |  _____________|
+   | |
+LL | |     ()
+   | |______- call expression requires function
+
+error[E0618]: expected function, found `{integer}`
+  --> $DIR/missing-semicolon.rs:35:5
+   |
+LL |       5
+   |       ^- help: consider using a semicolon here to finish the statement: `;`
+   |  _____|
+   | |
+LL | |     ();
+   | |______- call expression requires function
+
+error: aborting due to 7 previous errors
+
+For more information about this error, try `rustc --explain E0618`.