SI-6810 Disallow EOL in char literal

It's clear that char literals are one-lined like normal
string literals.

By the same token, pun intended, char literals accept
unicode escapes the same as string literals, including
`\u000A`.

This commit adds the usual exclusions (CR, NL, SU).

The spec is outdated in outlawing chars that are not
"printable", in particular, the ASCII control codes.
The original intention may have been that the ordinary
string escapes are required, such as "\b\n". Note that
some common escapes are absent, such as "\a".

1 files changed, 5 insertions, 3 deletions

diff --git a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
index 92833d647b..d5cb0d6a3b 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
@@ -515,7 +515,7 @@ trait Scanners extends ScannersCommon {
               charLitOr(getIdentRest)
             else if (isOperatorPart(ch) && (ch != '\\'))
               charLitOr(getOperatorRest)
-            else {
+            else if (!isAtEnd && (ch != SU && ch != CR && ch != LF || isUnicodeEscape)) {
               getLitChar()
               if (ch == '\'') {
                 nextChar()
@@ -525,6 +525,8 @@ trait Scanners extends ScannersCommon {
                 syntaxError("unclosed character literal")
               }
             }
+            else
+              syntaxError("unclosed character literal")
           }
           fetchSingleQuote()
         case '.' =>
@@ -690,7 +692,7 @@ trait Scanners extends ScannersCommon {
 
     private def unclosedStringLit(): Unit = syntaxError("unclosed string literal")
 
-    private def getRawStringLit(): Unit = {
+    @tailrec private def getRawStringLit(): Unit = {
       if (ch == '\"') {
         nextRawChar()
         if (isTripleQuote()) {
@@ -707,7 +709,7 @@ trait Scanners extends ScannersCommon {
       }
     }
 
-    @scala.annotation.tailrec private def getStringPart(multiLine: Boolean): Unit = {
+    @tailrec private def getStringPart(multiLine: Boolean): Unit = {
       def finishStringPart() = {
         setStrVal()
         token = STRINGPART