Merge pull request #13442 from som-snytt/issue/13440

Avoid shadowing of name 'name'

Author: griggt

compiler/src/dotty/tools/dotc/parsing/Scanners.scala

@@ -135,10 +135,13 @@ object Scanners {
       */
     protected def putChar(c: Char): Unit = litBuf.append(c)
 
-    /** Clear buffer and set name and token
-     *  If `target` is different from `this`, don't treat identifiers as end tokens
+    /** Finish an IDENTIFIER with `this.name`. */
+    inline def finishNamed(): Unit = finishNamedToken(IDENTIFIER, this)
+
+    /** Clear buffer and set name and token.
+     *  If `target` is different from `this`, don't treat identifiers as end tokens.
      */
-    def finishNamed(idtoken: Token = IDENTIFIER, target: TokenData = this): Unit =
+    def finishNamedToken(idtoken: Token, target: TokenData): Unit =
       target.name = termName(litBuf.chars, 0, litBuf.length)
       litBuf.clear()
       target.token = idtoken
@@ -242,24 +245,18 @@ object Scanners {
     /** A buffer for comments */
     private val commentBuf = CharBuffer()
 
-    private def handleMigration(keyword: Token): Token =
-      if scala3keywords.contains(keyword) && migrateTo3 then treatAsIdent()
-      else keyword
-
-    private def treatAsIdent(): Token =
-      val name0 = name  // don't capture the `name` var in the message closure, it may be null later
-      report.errorOrMigrationWarning(
-        i"$name0 is now a keyword, write `$name0` instead of $name0 to keep it as an identifier",
-        sourcePos())
-      patch(source, Span(offset), "`")
-      patch(source, Span(offset + name.length), "`")
-      IDENTIFIER
-
-    def toToken(name: SimpleName): Token = {
-      val idx = name.start
+    def toToken(identifier: SimpleName): Token =
+      def handleMigration(keyword: Token): Token =
+        if scala3keywords.contains(keyword) && migrateTo3 then
+          val what = tokenString(keyword)
+          report.errorOrMigrationWarning(i"$what is now a keyword, write `$what` instead of $what to keep it as an identifier", sourcePos())
+          patch(source, Span(offset), "`")
+          patch(source, Span(offset + identifier.length), "`")
+          IDENTIFIER
+        else keyword
+      val idx = identifier.start
       if (idx >= 0 && idx <= lastKeywordStart) handleMigration(kwArray(idx))
       else IDENTIFIER
-    }
 
     def newTokenData: TokenData = new TokenData {}
 
@@ -1002,7 +999,7 @@ object Scanners {
       getLitChars('`')
       if (ch == '`') {
         nextChar()
-        finishNamed(BACKQUOTED_IDENT)
+        finishNamedToken(BACKQUOTED_IDENT, target = this)
         if (name.length == 0)
           error("empty quoted identifier")
         else if (name == nme.WILDCARD)
@@ -1168,7 +1165,7 @@ object Scanners {
             nextRawChar()
             ch != SU && Character.isUnicodeIdentifierPart(ch)
           do ()
-          finishNamed(target = next)
+          finishNamedToken(IDENTIFIER, target = next)
         }
         else
           error("invalid string interpolation: `$$`, `$\"`, `$`ident or `$`BlockExpr expected")

tests/neg-custom-args/fatal-warnings/i13440.check

@@ -1,4 +1,12 @@
--- Error: tests/neg-custom-args/fatal-warnings/i13440.scala:3:13 -------------------------------------------------------
-3 |case class A(enum: List[Int] = Nil) // error
+-- Error: tests/neg-custom-args/fatal-warnings/i13440.scala:3:4 --------------------------------------------------------
+3 |def given = 42 // error
+  |    ^
+  |    given is now a keyword, write `given` instead of given to keep it as an identifier
+-- Error: tests/neg-custom-args/fatal-warnings/i13440.scala:5:13 -------------------------------------------------------
+5 |case class C(enum: List[Int] = Nil) { // error
   |             ^
   |             enum is now a keyword, write `enum` instead of enum to keep it as an identifier
+-- Error: tests/neg-custom-args/fatal-warnings/i13440.scala:6:11 -------------------------------------------------------
+6 |  val s = s"$enum" // error
+  |           ^
+  |           enum is now a keyword, write `enum` instead of enum to keep it as an identifier

tests/neg-custom-args/fatal-warnings/i13440.scala

@@ -1,3 +1,7 @@
 import language.`3.0-migration`
 
-case class A(enum: List[Int] = Nil) // error
+def given = 42 // error
+
+case class C(enum: List[Int] = Nil) { // error
+  val s = s"$enum" // error
+}