From 141167111e2e75e443663e113b997308d3e69f90 Mon Sep 17 00:00:00 2001
From: Som Snytt <som.snytt@gmail.com>
Date: Fri, 9 Apr 2021 03:39:20 -0700
Subject: [PATCH 1/6] Test status quo for leading infix

---
 .../scala/tools/nsc/ast/parser/Scanners.scala |  4 +-
 test/files/neg/multiLineOps.check             |  2 +-
 test/files/neg/multiLineOps.scala             |  4 +-
 test/files/neg/t12071.check                   | 37 +++++++++++++++++++
 test/files/neg/t12071.scala                   | 36 ++++++++++++++++++
 test/files/run/t12071.scala                   | 28 ++++++++++++++
 6 files changed, 106 insertions(+), 5 deletions(-)
 create mode 100644 test/files/neg/t12071.check
 create mode 100644 test/files/neg/t12071.scala
 create mode 100644 test/files/run/t12071.scala

diff --git a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
index 9d1f7b55a91e..aca8096852bd 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
@@ -469,8 +469,8 @@ trait Scanners extends ScannersCommon {
           val msg = """|Line starts with an operator that in future
                        |will be taken as an infix expression continued from the previous line.
                        |To force the previous interpretation as a separate statement,
-                       |add an explicit `;`, add an empty line, or remove spaces after the operator.""".stripMargin
-          deprecationWarning(msg, "2.13.2")
+                       |add an explicit `;`, add an empty line, or remove spaces after the operator."""
+          deprecationWarning(msg.stripMargin, "2.13.2")
           insertNL(NEWLINE)
         }
       }
diff --git a/test/files/neg/multiLineOps.check b/test/files/neg/multiLineOps.check
index c9882d57e1c2..32b8a5366e17 100644
--- a/test/files/neg/multiLineOps.check
+++ b/test/files/neg/multiLineOps.check
@@ -1,5 +1,5 @@
 multiLineOps.scala:6: warning: a pure expression does nothing in statement position; multiline expressions may require enclosing parentheses
-    +3 // error: Expected a toplevel definition
+    +3 // error: Expected a toplevel definition (or pure expr warning, here)
     ^
 error: No warnings can be incurred under -Werror.
 1 warning
diff --git a/test/files/neg/multiLineOps.scala b/test/files/neg/multiLineOps.scala
index 792528620773..e1c2bfee6304 100644
--- a/test/files/neg/multiLineOps.scala
+++ b/test/files/neg/multiLineOps.scala
@@ -1,7 +1,7 @@
-// scalac: -Werror -Xsource:3
+// scalac: -Werror -Xlint -Xsource:3
 
 class Test {
   val x = 1
     + 2
-    +3 // error: Expected a toplevel definition
+    +3 // error: Expected a toplevel definition (or pure expr warning, here)
 }
diff --git a/test/files/neg/t12071.check b/test/files/neg/t12071.check
new file mode 100644
index 000000000000..6c8167faa8ec
--- /dev/null
+++ b/test/files/neg/t12071.check
@@ -0,0 +1,37 @@
+t12071.scala:15: error: not found: value c c
+    `c c` i
+    ^
+t12071.scala:15: error: postfix operator i needs to be enabled
+by making the implicit value scala.language.postfixOps visible.
+This can be achieved by adding the import clause 'import scala.language.postfixOps'
+or by setting the compiler option -language:postfixOps.
+See the Scaladoc for value scala.language.postfixOps for a discussion
+why the feature needs to be explicitly enabled.
+    `c c` i
+          ^
+t12071.scala:20: warning: Line starts with an operator that in future
+will be taken as an infix expression continued from the previous line.
+To force the previous interpretation as a separate statement,
+add an explicit `;`, add an empty line, or remove spaces after the operator.
+    + 2
+    ^
+t12071.scala:25: warning: Line starts with an operator that in future
+will be taken as an infix expression continued from the previous line.
+To force the previous interpretation as a separate statement,
+add an explicit `;`, add an empty line, or remove spaces after the operator.
+    + 1
+    ^
+t12071.scala:28: warning: Line starts with an operator that in future
+will be taken as an infix expression continued from the previous line.
+To force the previous interpretation as a separate statement,
+add an explicit `;`, add an empty line, or remove spaces after the operator.
+    `test-1` + `test-2`
+    ^
+t12071.scala:31: warning: Line starts with an operator that in future
+will be taken as an infix expression continued from the previous line.
+To force the previous interpretation as a separate statement,
+add an explicit `;`, add an empty line, or remove spaces after the operator.
+    `compareTo` (2 - 1)
+    ^
+4 warnings
+2 errors
diff --git a/test/files/neg/t12071.scala b/test/files/neg/t12071.scala
new file mode 100644
index 000000000000..28dc895c03c6
--- /dev/null
+++ b/test/files/neg/t12071.scala
@@ -0,0 +1,36 @@
+// scalac: -Werror -Xlint
+
+class C {
+  def `c c`(n: Int): Int = n + 1
+}
+
+// backticked operator is candidate for multiline infix,
+// but backticked value is an innocent bystander.
+//
+class t12071 {
+  def c: C = ???
+  def i: Int = 42
+  def `n n`: Int = 17
+  def f = c
+    `c c` i
+  def g = i +
+    `n n`
+  def basic =
+      1
+    + 2
+}
+
+object C {
+  def x = 42
+    + 1
+
+  def y = 1 +
+    `test-1` + `test-2`
+
+  def z = 2
+    `compareTo` (2 - 1)
+
+  def `test-1`: Int = 23
+  def `test-2`: Int = 42
+  def compareTo(x: Int) = println("lol")
+}
diff --git a/test/files/run/t12071.scala b/test/files/run/t12071.scala
new file mode 100644
index 000000000000..5950647a1526
--- /dev/null
+++ b/test/files/run/t12071.scala
@@ -0,0 +1,28 @@
+// scalac: -Werror -Xlint -Xsource:3
+
+class C {
+  def `c c`(n: Int): Int = n + 1
+}
+
+// backticked operator is candidate for multiline infix,
+// but backticked value is an innocent bystander.
+//
+class t12071 {
+  def c: C = new C
+  def i: Int = 42
+  def `n n`: Int = 27
+  def f = c
+    `c c` i
+  def g = i +
+    `n n`
+  def basic =
+      1
+    + 2
+}
+
+object Test extends App {
+  val t = new t12071
+  assert(t.f == 43)
+  assert(t.g == 69)
+  assert(t.basic == 3)
+}

From 1924d2dc4a3d66163387cb5eae652a6071168dc7 Mon Sep 17 00:00:00 2001
From: Som Snytt <som.snytt@gmail.com>
Date: Fri, 9 Apr 2021 04:58:13 -0700
Subject: [PATCH 2/6] Postfix error doesn't suppress warnings

---
 src/compiler/scala/tools/nsc/Reporting.scala | 8 ++++++--
 test/files/neg/t12071.check                  | 4 ++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/compiler/scala/tools/nsc/Reporting.scala b/src/compiler/scala/tools/nsc/Reporting.scala
index c69a60f3f8be..cd26e72a7cfd 100644
--- a/src/compiler/scala/tools/nsc/Reporting.scala
+++ b/src/compiler/scala/tools/nsc/Reporting.scala
@@ -246,8 +246,12 @@ trait Reporting extends internal.Reporting { self: ast.Positions with Compilatio
         && parentFileName(pos.source).getOrElse("") == "xsbt"
         && Thread.currentThread.getStackTrace.exists(_.getClassName.startsWith("sbt."))
       )
-      if (required && !isSbtCompat) reporter.error(pos, msg)
-      else warning(pos, msg, featureCategory(featureTrait.nameString), site)
+      // on postfix error, include interesting infix warning
+      def isXfix = featureName == "postfixOps" && suspendedMessages.get(pos.source).map(_.exists(w => pos.includes(w.pos))).getOrElse(false)
+      if (required && !isSbtCompat) {
+        val amended = if (isXfix) s"$msg\n${suspendedMessages(pos.source).filter(pos includes _.pos).map(_.msg).mkString("\n")}" else msg
+        reporter.error(pos, amended)
+      } else warning(pos, msg, featureCategory(featureTrait.nameString), site)
     }
 
     // Used in the optimizer where we don't have no symbols, the site string is created from the class internal name and method name.
diff --git a/test/files/neg/t12071.check b/test/files/neg/t12071.check
index 6c8167faa8ec..88198baf3274 100644
--- a/test/files/neg/t12071.check
+++ b/test/files/neg/t12071.check
@@ -7,6 +7,10 @@ This can be achieved by adding the import clause 'import scala.language.postfixO
 or by setting the compiler option -language:postfixOps.
 See the Scaladoc for value scala.language.postfixOps for a discussion
 why the feature needs to be explicitly enabled.
+Line starts with an operator that in future
+will be taken as an infix expression continued from the previous line.
+To force the previous interpretation as a separate statement,
+add an explicit `;`, add an empty line, or remove spaces after the operator.
     `c c` i
           ^
 t12071.scala:20: warning: Line starts with an operator that in future

From 838092d2b8668bb57a662020d6653cfe4b0701d1 Mon Sep 17 00:00:00 2001
From: Som Snytt <som.snytt@gmail.com>
Date: Sat, 10 Apr 2021 14:08:49 -0700
Subject: [PATCH 3/6] Backport Allow infix operators on their own line

---
 .../scala/tools/nsc/ast/parser/Scanners.scala |  8 ++++----
 test/files/pos/leading-infix-op.scala         | 19 +++++++++++++++++++
 test/files/run/multiLineOps.scala             |  5 +++--
 3 files changed, 26 insertions(+), 6 deletions(-)
 create mode 100644 test/files/pos/leading-infix-op.scala

diff --git a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
index aca8096852bd..d727806e9c0b 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
@@ -448,11 +448,11 @@ trait Scanners extends ScannersCommon {
        */
       def isLeadingInfixOperator =
         allowLeadingInfixOperators &&
-        (token == BACKQUOTED_IDENT ||
-         token == IDENTIFIER && isOperatorPart(name.charAt(name.length - 1))) &&
-        (ch == ' ') && lookingAhead {
+        (token == BACKQUOTED_IDENT || token == IDENTIFIER && isOperatorPart(name.charAt(name.length - 1))) &&
+        ch <= ' ' && lookingAhead {
           // force a NEWLINE after current token if it is on its own line
-          isSimpleExprIntroToken(token)
+          isSimpleExprIntroToken(token) ||
+          token == NEWLINE && { nextToken() ; isSimpleExprIntroToken(token) }
         }
 
       /* Insert NEWLINE or NEWLINES if
diff --git a/test/files/pos/leading-infix-op.scala b/test/files/pos/leading-infix-op.scala
new file mode 100644
index 000000000000..4b60aa67b8c1
--- /dev/null
+++ b/test/files/pos/leading-infix-op.scala
@@ -0,0 +1,19 @@
+
+// scalac: -Xsource:3
+
+trait T {
+  def f(x: Int): Boolean =
+    x < 0
+    ||
+    x > 0
+    &&
+    x != 3
+
+  def g(x: Option[Int]) = x match {
+    case Some(err) =>
+      println("hi")
+      ???
+    case None =>
+      ???
+  }
+}
diff --git a/test/files/run/multiLineOps.scala b/test/files/run/multiLineOps.scala
index 0bba854027fc..793a8a49eebb 100644
--- a/test/files/run/multiLineOps.scala
+++ b/test/files/run/multiLineOps.scala
@@ -1,6 +1,7 @@
 // scalac: -Xsource:3
 //
-// without backticks, "not found: value +"
+// was: without backticks, "not found: value +" (but parsed here as +a * 6, where backticks fool the lexer)
+// now: + is taken as "solo" infix op
 //
 object Test extends App {
   val a = 7
@@ -8,5 +9,5 @@ object Test extends App {
     + //
     `a` * 6
 
-  assert(x == 1)
+  assert(x == 1 + 42, x)  // was: 1
 }

From fc47f58f161c9e1c0e8c0d62e3c6656d27529c3d Mon Sep 17 00:00:00 2001
From: Som Snytt <som.snytt@gmail.com>
Date: Sun, 11 Apr 2021 00:02:53 -0700
Subject: [PATCH 4/6] Backport Refine condition of leading infix operator

---
 .../scala/tools/nsc/ast/parser/Scanners.scala | 23 +++++++++++++++----
 test/files/neg/t12071.scala                   |  6 +++++
 test/files/pos/i11371.scala                   | 21 +++++++++++++++++
 3 files changed, 45 insertions(+), 5 deletions(-)
 create mode 100644 test/files/pos/i11371.scala

diff --git a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
index d727806e9c0b..683614c76451 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
@@ -442,6 +442,23 @@ trait Scanners extends ScannersCommon {
         token = nl
       }
 
+      /* A leading infix operator must be followed by a lexically suitable expression.
+       * Usually any simple expr will do. However, if the op is backtick style, make
+       * sure it is not followed by a binary op, which suggests the backticked identifier
+       * is a reference.
+       */
+      def followedByInfixRHS: Boolean = {
+        val current = token
+        def isOp: Boolean = token == IDENTIFIER && isOperatorPart(name.charAt(name.length - 1))
+        def isCandidateInfixRHS: Boolean =
+          isSimpleExprIntroToken(token) &&
+          (current != BACKQUOTED_IDENT || !isOp || nme.raw.isUnary(name))
+        lookingAhead {
+          isCandidateInfixRHS ||
+          token == NEWLINE && { nextToken() ; isCandidateInfixRHS }
+        }
+      }
+
       /* A leading symbolic or backquoted identifier is treated as an infix operator
        * if it is followed by at least one ' ' and a token on the same line
        * that can start an expression.
@@ -449,11 +466,7 @@ trait Scanners extends ScannersCommon {
       def isLeadingInfixOperator =
         allowLeadingInfixOperators &&
         (token == BACKQUOTED_IDENT || token == IDENTIFIER && isOperatorPart(name.charAt(name.length - 1))) &&
-        ch <= ' ' && lookingAhead {
-          // force a NEWLINE after current token if it is on its own line
-          isSimpleExprIntroToken(token) ||
-          token == NEWLINE && { nextToken() ; isSimpleExprIntroToken(token) }
-        }
+        ch <= ' ' && followedByInfixRHS
 
       /* Insert NEWLINE or NEWLINES if
        * - we are after a newline
diff --git a/test/files/neg/t12071.scala b/test/files/neg/t12071.scala
index 28dc895c03c6..e08dc0815ec1 100644
--- a/test/files/neg/t12071.scala
+++ b/test/files/neg/t12071.scala
@@ -33,4 +33,10 @@ object C {
   def `test-1`: Int = 23
   def `test-2`: Int = 42
   def compareTo(x: Int) = println("lol")
+
+  var `test-3`: List[Int] = Nil
+
+  // since ++ is not unary, test-3 is not taken as an operator; this test doesn't fix y above.
+  def yy = List.empty[Int] ++
+    `test-3` ++ `test-3`
 }
diff --git a/test/files/pos/i11371.scala b/test/files/pos/i11371.scala
new file mode 100644
index 000000000000..74156b777c9f
--- /dev/null
+++ b/test/files/pos/i11371.scala
@@ -0,0 +1,21 @@
+// scalac: -Xsource:3
+//
+object HelloWorld {
+  def whileLoop: Int = {
+    var i = 0
+    var acc = 0
+    while (i < 3) {
+      var `i'` = 0
+      while (`i'` < 4) {
+        acc += (i * `i'`)
+        `i'` += 1
+      }
+      i += 1
+    }
+    acc
+  }
+
+  def main(args: Array[String]): Unit = {
+    println(s"hello world: ${whileLoop}")
+  }
+}

From 2efc7ed50678088473ec7414e78a7911f6611d88 Mon Sep 17 00:00:00 2001
From: Som Snytt <som.snytt@gmail.com>
Date: Thu, 15 Apr 2021 07:49:11 -0700
Subject: [PATCH 5/6] Backport Generalize isOperator and test for assignment op

---
 .../scala/tools/nsc/ast/parser/Scanners.scala | 28 +++++++++++--------
 test/files/neg/t12071.scala                   | 17 ++++++++---
 test/files/run/multiLineOps.scala             |  8 ++++--
 3 files changed, 34 insertions(+), 19 deletions(-)

diff --git a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
index 683614c76451..04e648100f6e 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
@@ -442,20 +442,23 @@ trait Scanners extends ScannersCommon {
         token = nl
       }
 
+      def isOperator: Boolean = token == BACKQUOTED_IDENT || token == IDENTIFIER && isOperatorPart(name.charAt(name.length - 1))
+
       /* A leading infix operator must be followed by a lexically suitable expression.
-       * Usually any simple expr will do. However, if the op is backtick style, make
-       * sure it is not followed by a binary op, which suggests the backticked identifier
-       * is a reference.
+       * Usually any simple expr will do. However, a backquoted identifier may serve as
+       * either an op or a reference. So the additional constraint is that the following
+       * token can't be an assignment operator. (Dotty disallows binary ops, hence the
+       * test for unary.) See run/multiLineOps.scala for 42 + `x` on 3 lines, where +
+       * is not leading infix because backquoted x is non-unary op.
        */
       def followedByInfixRHS: Boolean = {
-        val current = token
-        def isOp: Boolean = token == IDENTIFIER && isOperatorPart(name.charAt(name.length - 1))
-        def isCandidateInfixRHS: Boolean =
-          isSimpleExprIntroToken(token) &&
-          (current != BACKQUOTED_IDENT || !isOp || nme.raw.isUnary(name))
+        //def isCandidateInfixRHS: Boolean = isSimpleExprIntroToken(token) && (!isOperator || nme.raw.isUnary(name) || token == BACKQUOTED_IDENT)
+        def isAssignmentOperator: Boolean =
+          name.endsWith('=') && !name.startsWith('=') && isOperatorPart(name.startChar) &&
+          (name.length != 2 || (name.startChar match { case '!' | '<' | '>' => false case _ => true }))
+        def isCandidateInfixRHS: Boolean = isSimpleExprIntroToken(token) && (!isOperator || token == BACKQUOTED_IDENT || !isAssignmentOperator)
         lookingAhead {
-          isCandidateInfixRHS ||
-          token == NEWLINE && { nextToken() ; isCandidateInfixRHS }
+          isCandidateInfixRHS || token == NEWLINE && { nextToken() ; isCandidateInfixRHS }
         }
       }
 
@@ -465,8 +468,9 @@ trait Scanners extends ScannersCommon {
        */
       def isLeadingInfixOperator =
         allowLeadingInfixOperators &&
-        (token == BACKQUOTED_IDENT || token == IDENTIFIER && isOperatorPart(name.charAt(name.length - 1))) &&
-        ch <= ' ' && followedByInfixRHS
+        isOperator &&
+        (isWhitespace(ch) || ch == LF) &&
+        followedByInfixRHS
 
       /* Insert NEWLINE or NEWLINES if
        * - we are after a newline
diff --git a/test/files/neg/t12071.scala b/test/files/neg/t12071.scala
index e08dc0815ec1..e9eb18b9d89a 100644
--- a/test/files/neg/t12071.scala
+++ b/test/files/neg/t12071.scala
@@ -34,9 +34,18 @@ object C {
   def `test-2`: Int = 42
   def compareTo(x: Int) = println("lol")
 
-  var `test-3`: List[Int] = Nil
+  def yy = 1
+  /* fails in scala 3
+    +
+    `test-1`
+    +
+    `test-2`
+   */
+}
 
-  // since ++ is not unary, test-3 is not taken as an operator; this test doesn't fix y above.
-  def yy = List.empty[Int] ++
-    `test-3` ++ `test-3`
+object Test extends App {
+  println(C.x)
+  println(C.y)
+  println(C.z)
+  println(C.yy)
 }
diff --git a/test/files/run/multiLineOps.scala b/test/files/run/multiLineOps.scala
index 793a8a49eebb..ef319d9210dc 100644
--- a/test/files/run/multiLineOps.scala
+++ b/test/files/run/multiLineOps.scala
@@ -6,8 +6,10 @@
 object Test extends App {
   val a = 7
   val x = 1
-    + //
-    `a` * 6
+    +
+    `a`
+    *
+    6
 
-  assert(x == 1 + 42, x)  // was: 1
+  assert(x == 1 + 7 * 6, x)  // was: 1, now: successor(42)
 }

From d5cb78cc1337592f4e968647e714618cf49a1a26 Mon Sep 17 00:00:00 2001
From: Som Snytt <som.snytt@gmail.com>
Date: Tue, 11 May 2021 16:32:26 -0700
Subject: [PATCH 6/6] Infix warn on migration

---
 .../scala/tools/nsc/ast/parser/Scanners.scala      |  6 +++++-
 test/files/neg/multiLineOps.check                  |  2 +-
 test/files/neg/multiLineOps.scala                  |  2 +-
 test/files/neg/stmt-expr-discard.check             | 14 +-------------
 test/files/neg/t12071.scala                        |  2 +-
 test/files/neg/t9847.check                         | 14 +-------------
 6 files changed, 10 insertions(+), 30 deletions(-)

diff --git a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
index 04e648100f6e..17b46da9191c 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
@@ -13,6 +13,7 @@
 package scala.tools.nsc
 package ast.parser
 
+import scala.tools.nsc.settings.ScalaVersion
 import scala.tools.nsc.util.{CharArrayReader, CharArrayReaderData}
 import scala.reflect.internal.util._
 import scala.reflect.internal.Chars._
@@ -403,6 +404,9 @@ trait Scanners extends ScannersCommon {
       sepRegions = sepRegions.tail
     }
 
+    /** True to warn about migration change in infix syntax. */
+    private val infixMigration = settings.Xmigration.value <= ScalaVersion("2.13.2")
+
     /** Produce next token, filling TokenData fields of Scanner.
      */
     def nextToken(): Unit = {
@@ -487,7 +491,7 @@ trait Scanners extends ScannersCommon {
                        |will be taken as an infix expression continued from the previous line.
                        |To force the previous interpretation as a separate statement,
                        |add an explicit `;`, add an empty line, or remove spaces after the operator."""
-          deprecationWarning(msg.stripMargin, "2.13.2")
+          if (infixMigration) deprecationWarning(msg.stripMargin, "2.13.2")
           insertNL(NEWLINE)
         }
       }
diff --git a/test/files/neg/multiLineOps.check b/test/files/neg/multiLineOps.check
index 32b8a5366e17..e3d865c984d4 100644
--- a/test/files/neg/multiLineOps.check
+++ b/test/files/neg/multiLineOps.check
@@ -1,5 +1,5 @@
 multiLineOps.scala:6: warning: a pure expression does nothing in statement position; multiline expressions may require enclosing parentheses
-    +3 // error: Expected a toplevel definition (or pure expr warning, here)
+    +3 // warning: a pure expression does nothing in statement position
     ^
 error: No warnings can be incurred under -Werror.
 1 warning
diff --git a/test/files/neg/multiLineOps.scala b/test/files/neg/multiLineOps.scala
index e1c2bfee6304..4a92fd9f2c0c 100644
--- a/test/files/neg/multiLineOps.scala
+++ b/test/files/neg/multiLineOps.scala
@@ -3,5 +3,5 @@
 class Test {
   val x = 1
     + 2
-    +3 // error: Expected a toplevel definition (or pure expr warning, here)
+    +3 // warning: a pure expression does nothing in statement position
 }
diff --git a/test/files/neg/stmt-expr-discard.check b/test/files/neg/stmt-expr-discard.check
index 250de20f98d2..cc22eb1d843b 100644
--- a/test/files/neg/stmt-expr-discard.check
+++ b/test/files/neg/stmt-expr-discard.check
@@ -1,15 +1,3 @@
-stmt-expr-discard.scala:5: warning: Line starts with an operator that in future
-will be taken as an infix expression continued from the previous line.
-To force the previous interpretation as a separate statement,
-add an explicit `;`, add an empty line, or remove spaces after the operator.
-    + 2
-    ^
-stmt-expr-discard.scala:6: warning: Line starts with an operator that in future
-will be taken as an infix expression continued from the previous line.
-To force the previous interpretation as a separate statement,
-add an explicit `;`, add an empty line, or remove spaces after the operator.
-    - 4
-    ^
 stmt-expr-discard.scala:5: warning: a pure expression does nothing in statement position; multiline expressions may require enclosing parentheses
     + 2
     ^
@@ -17,5 +5,5 @@ stmt-expr-discard.scala:6: warning: a pure expression does nothing in statement
     - 4
     ^
 error: No warnings can be incurred under -Werror.
-4 warnings
+2 warnings
 1 error
diff --git a/test/files/neg/t12071.scala b/test/files/neg/t12071.scala
index e9eb18b9d89a..f3f9529c147b 100644
--- a/test/files/neg/t12071.scala
+++ b/test/files/neg/t12071.scala
@@ -1,4 +1,4 @@
-// scalac: -Werror -Xlint
+// scalac: -Werror -Xlint -Xmigration:2.13
 
 class C {
   def `c c`(n: Int): Int = n + 1
diff --git a/test/files/neg/t9847.check b/test/files/neg/t9847.check
index 27899eb467be..d3c6c485f72c 100644
--- a/test/files/neg/t9847.check
+++ b/test/files/neg/t9847.check
@@ -1,15 +1,3 @@
-t9847.scala:10: warning: Line starts with an operator that in future
-will be taken as an infix expression continued from the previous line.
-To force the previous interpretation as a separate statement,
-add an explicit `;`, add an empty line, or remove spaces after the operator.
-  + 1
-  ^
-t9847.scala:14: warning: Line starts with an operator that in future
-will be taken as an infix expression continued from the previous line.
-To force the previous interpretation as a separate statement,
-add an explicit `;`, add an empty line, or remove spaces after the operator.
-  + 1
-  ^
 t9847.scala:6: warning: discarded non-Unit value
   def f(): Unit = 42
                   ^
@@ -47,5 +35,5 @@ t9847.scala:24: warning: a pure expression does nothing in statement position; m
   class D { 42 ; 17 }
                  ^
 error: No warnings can be incurred under -Werror.
-14 warnings
+12 warnings
 1 error