A little help for what's changed

scala · Mar 8, 2021 · 9967206 · 9967206
1 parent 9eb0f73
commit 9967206
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Showing 2 changed files with 18 additions and 10 deletions.
diff --git a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
@@ -854,7 +854,12 @@ trait Scanners extends ScannersCommon {
       } else unclosedStringLit()
     }
 
-    private def unclosedStringLit(): Unit = syntaxError("unclosed string literal")
+    private def unclosedStringLit(seenEscapedQuoteInInterpolation: Boolean = false): Unit = {
+      val note =
+        if (seenEscapedQuoteInInterpolation) "; note that `\\\"` no longer closes single-quoted interpolated string literals since 2.13.6, you can use a triple-quoted string instead"
+        else ""
+      syntaxError(s"unclosed string literal$note")
+    }
 
     private def replaceUnicodeEscapesInTriple(): Unit = 
       if(strVal != null) {
@@ -890,7 +895,8 @@ trait Scanners extends ScannersCommon {
       }
     }
 
-    @tailrec private def getStringPart(multiLine: Boolean): Unit = {
+    // for interpolated strings
+    @tailrec private def getStringPart(multiLine: Boolean, seenEscapedQuote: Boolean = false): Unit = {
       def finishStringPart() = {
         setStrVal()
         token = STRINGPART
@@ -904,7 +910,7 @@ trait Scanners extends ScannersCommon {
             setStrVal()
             token = STRINGLIT
           } else
-            getStringPart(multiLine)
+            getStringPart(multiLine, seenEscapedQuote)
         } else {
           nextChar()
           setStrVal()
@@ -913,17 +919,18 @@ trait Scanners extends ScannersCommon {
       } else if (ch == '\\' && !multiLine) {
         putChar(ch)
         nextRawChar()
-        if (ch == '"' || ch == '\\') {
+        val q = ch == '"'
+        if (q || ch == '\\') {
           putChar(ch)
           nextRawChar()
         }
-        getStringPart(multiLine)
+        getStringPart(multiLine, seenEscapedQuote || q)
       } else if (ch == '$') {
         nextRawChar()
         if (ch == '$') {
           putChar(ch)
           nextRawChar()
-          getStringPart(multiLine)
+          getStringPart(multiLine, seenEscapedQuote)
         } else if (ch == '{') {
           finishStringPart()
           nextRawChar()
@@ -953,13 +960,14 @@ trait Scanners extends ScannersCommon {
         if (isUnclosedLiteral) {
           if (multiLine)
             incompleteInputError("unclosed multi-line string literal")
-          else
-            unclosedStringLit()
+          else {
+            unclosedStringLit(seenEscapedQuote)
+          }
         }
         else {
           putChar(ch)
           nextRawChar()
-          getStringPart(multiLine)
+          getStringPart(multiLine, seenEscapedQuote)
         }
       }
     }

diff --git a/test/files/neg/t6476.check b/test/files/neg/t6476.check
@@ -1,4 +1,4 @@
-t6476.scala:8: error: unclosed string literal
+t6476.scala:8: error: unclosed string literal; note that `\"` no longer closes single-quoted interpolated string literals since 2.13.6, you can use a triple-quoted string instead
   mimi"\"
        ^
 1 error