Underline assignment correctly in error message

Author: liufengyun

compiler/src/dotty/tools/dotc/transform/init/Semantic.scala

@@ -1349,12 +1349,12 @@ object Semantic:
         case Select(qual, _) =>
           eval(qual, thisV, klass)
           val res = eval(rhs, thisV, klass)
-          extendTrace(rhs) {
+          extendTrace(expr) {
             res.ensureHot("The RHS of reassignment must be fully initialized.")
           }
         case id: Ident =>
           val res = eval(rhs, thisV, klass)
-          extendTrace(rhs) {
+          extendTrace(expr) {
             res.ensureHot("The RHS of reassignment must be fully initialized.")
           }
 

tests/init/neg/inherit-non-hot.check

@@ -1,15 +1,15 @@
--- Error: tests/init/neg/inherit-non-hot.scala:6:34 --------------------------------------------------------------------
+-- Error: tests/init/neg/inherit-non-hot.scala:6:32 --------------------------------------------------------------------
 6 |            if b == null then b = new B(this) // error
-  |                                  ^^^^^^^^^^^
-  |                                  The RHS of reassignment must be fully initialized. Calling trace:
-  |                                  -> class C extends A {	[ inherit-non-hot.scala:15 ]
-  |                                     ^
-  |                                  -> val bAgain = toB.getBAgain	[ inherit-non-hot.scala:16 ]
-  |                                                  ^^^
-  |                                  -> def toB: B =	[ inherit-non-hot.scala:5 ]
-  |                                     ^
-  |                                  -> if b == null then b = new B(this) // error	[ inherit-non-hot.scala:6 ]
-  |                                                           ^^^^^^^^^^^
+  |                              ^^^^^^^^^^^^^^^
+  |                              The RHS of reassignment must be fully initialized. Calling trace:
+  |                              -> class C extends A {	[ inherit-non-hot.scala:15 ]
+  |                                 ^
+  |                              -> val bAgain = toB.getBAgain	[ inherit-non-hot.scala:16 ]
+  |                                              ^^^
+  |                              -> def toB: B =	[ inherit-non-hot.scala:5 ]
+  |                                 ^
+  |                              -> if b == null then b = new B(this) // error	[ inherit-non-hot.scala:6 ]
+  |                                                   ^^^^^^^^^^^^^^^
   |
-  |                                  Promoting the value to fully initialized failed due to the following problem:
-  |                                  Cannot prove that the field val a is fully initialized.
+  |                              Promoting the value to fully initialized failed due to the following problem:
+  |                              Cannot prove that the field val a is fully initialized.

tests/init/neg/local-warm4.check

@@ -1,26 +1,26 @@
--- Error: tests/init/neg/local-warm4.scala:18:20 -----------------------------------------------------------------------
+-- Error: tests/init/neg/local-warm4.scala:18:18 -----------------------------------------------------------------------
 18 |                a = newA // error
-   |                    ^^^^
-   |                    The RHS of reassignment must be fully initialized. Calling trace:
-   |                    -> object localWarm {	[ local-warm4.scala:1 ]
-   |                       ^
-   |                    -> val a = new A(5)	[ local-warm4.scala:26 ]
-   |                               ^^^^^^^^
-   |                    -> class A(x: Int) extends Foo(x) {	[ local-warm4.scala:6 ]
-   |                       ^
-   |                    -> val b = new B(y)	[ local-warm4.scala:10 ]
-   |                               ^^^^^^^^
-   |                    -> class B(x: Int) extends A(x) {	[ local-warm4.scala:13 ]
-   |                       ^
-   |                    -> class A(x: Int) extends Foo(x) {	[ local-warm4.scala:6 ]
-   |                       ^
-   |                    -> increment()	[ local-warm4.scala:9 ]
-   |                       ^^^^^^^^^^^
-   |                    -> override def increment(): Unit = {	[ local-warm4.scala:15 ]
-   |                       ^
-   |                    -> updateA()	[ local-warm4.scala:21 ]
-   |                       ^^^^^^^^^
-   |                    -> def updateA(): Unit = {	[ local-warm4.scala:16 ]
-   |                       ^
-   |                    -> a = newA // error	[ local-warm4.scala:18 ]
-   |                           ^^^^
+   |                ^^^^^^^^
+   |                The RHS of reassignment must be fully initialized. Calling trace:
+   |                -> object localWarm {	[ local-warm4.scala:1 ]
+   |                   ^
+   |                -> val a = new A(5)	[ local-warm4.scala:26 ]
+   |                           ^^^^^^^^
+   |                -> class A(x: Int) extends Foo(x) {	[ local-warm4.scala:6 ]
+   |                   ^
+   |                -> val b = new B(y)	[ local-warm4.scala:10 ]
+   |                           ^^^^^^^^
+   |                -> class B(x: Int) extends A(x) {	[ local-warm4.scala:13 ]
+   |                   ^
+   |                -> class A(x: Int) extends Foo(x) {	[ local-warm4.scala:6 ]
+   |                   ^
+   |                -> increment()	[ local-warm4.scala:9 ]
+   |                   ^^^^^^^^^^^
+   |                -> override def increment(): Unit = {	[ local-warm4.scala:15 ]
+   |                   ^
+   |                -> updateA()	[ local-warm4.scala:21 ]
+   |                   ^^^^^^^^^
+   |                -> def updateA(): Unit = {	[ local-warm4.scala:16 ]
+   |                   ^
+   |                -> a = newA // error	[ local-warm4.scala:18 ]
+   |                   ^^^^^^^^