SI-8281 check for unbound placeholder parameters in quasiquote parser

Author: densh

src/compiler/scala/tools/reflect/quasiquotes/Parsers.scala

@@ -22,7 +22,8 @@ trait Parsers { self: Quasiquotes =>
     def parse(code: String): Tree = {
       try {
         val file = new BatchSourceFile(nme.QUASIQUOTE_FILE, code)
-        new QuasiquoteParser(file).parseRule(entryPoint)
+        val parser = new QuasiquoteParser(file)
+        parser.checkNoEscapingPlaceholders { parser.parseRule(entryPoint) }
       } catch {
         case mi: MalformedInput => c.abort(correspondingPosition(mi.offset), mi.msg)
       }

test/files/scalacheck/quasiquotes/ErrorProps.scala

@@ -160,6 +160,18 @@ object ErrorProps extends QuasiquoteProperties("errors") {
       q"$n"
     """)
 
+  property("SI-8211: check unbound placeholder paremeters") = fails(
+    "unbound placeholder parameter",
+    """
+      q"_"
+    """)
+
+  property("SI-8211: check unbound wildcard types") = fails(
+    "unbound wildcard type",
+    """
+      tq"_"
+    """)
+
   // // Make sure a nice error is reported in this case
   // { import Flag._; val mods = NoMods; q"lazy $mods val x: Int" }
 }