Merge pull request #3974 from xeno-by/topic/buffer-pattern-expander-errors

This ensures that typechecking custom unapplications in silent mode

7 files changed, 44 insertions, 12 deletions

diff --git a/src/compiler/scala/tools/nsc/transform/UnCurry.scala b/src/compiler/scala/tools/nsc/transform/UnCurry.scala
index 9b85f1b36a..3544dc9966 100644
--- a/src/compiler/scala/tools/nsc/transform/UnCurry.scala
+++ b/src/compiler/scala/tools/nsc/transform/UnCurry.scala
@@ -459,7 +459,7 @@ abstract class UnCurry extends InfoTransform
           case UnApply(fn, args) =>
             val fn1   = transform(fn)
             val args1 = fn.symbol.name match {
-              case nme.unapplySeq => transformArgs(tree.pos, fn.symbol, args, patmat.alignPatterns(tree).expectedTypes)
+              case nme.unapplySeq => transformArgs(tree.pos, fn.symbol, args, patmat.alignPatterns(global.typer.context, tree).expectedTypes)
               case _              => args
             }
             treeCopy.UnApply(tree, fn1, args1)
diff --git a/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala b/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala
index 0eaffe7cee..d862805a07 100644
--- a/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala
+++ b/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala
@@ -377,8 +377,8 @@ trait MatchTranslation {
     object ExtractorCall {
       // TODO: check unargs == args
       def apply(tree: Tree): ExtractorCall = tree match {
-        case UnApply(unfun, args) => new ExtractorCallRegular(alignPatterns(tree), unfun, args) // extractor
-        case Apply(fun, args)     => new ExtractorCallProd(alignPatterns(tree), fun, args)      // case class
+        case UnApply(unfun, args) => new ExtractorCallRegular(alignPatterns(context, tree), unfun, args) // extractor
+        case Apply(fun, args)     => new ExtractorCallProd(alignPatterns(context, tree), fun, args)      // case class
       }
     }
 
diff --git a/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala b/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala
index 8f21f4ecfc..79f5e3bee8 100644
--- a/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala
+++ b/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala
@@ -18,6 +18,7 @@ trait ScalacPatternExpanders {
   import global._
   import definitions._
   import treeInfo._
+  import analyzer._
 
   type PatternAligned = ScalacPatternExpander#Aligned
 
@@ -94,7 +95,7 @@ trait ScalacPatternExpanders {
     def tupleExtractor(extractor: Extractor): Extractor =
       extractor.copy(fixed = tupleType(extractor.fixed) :: Nil)
 
-    private def validateAligned(tree: Tree, aligned: Aligned): Aligned = {
+    private def validateAligned(context: Context, tree: Tree, aligned: Aligned): Aligned = {
       import aligned._
 
       def owner         = tree.symbol.owner
@@ -103,8 +104,8 @@ trait ScalacPatternExpanders {
       def offerString   = if (extractor.isErroneous) "" else s" offering $offering"
       def arityExpected = ( if (extractor.hasSeq) "at least " else "" ) + productArity
 
-      def err(msg: String)         = reporter.error(tree.pos, msg)
-      def warn(msg: String)        = reporter.warning(tree.pos, msg)
+      def err(msg: String)         = context.error(tree.pos, msg)
+      def warn(msg: String)        = context.warning(tree.pos, msg)
       def arityError(what: String) = err(s"$what patterns for $owner$offerString: expected $arityExpected, found $totalArity")
 
       if (isStar && !isSeq)
@@ -117,7 +118,7 @@ trait ScalacPatternExpanders {
       aligned
     }
 
-    def apply(sel: Tree, args: List[Tree]): Aligned = {
+    def apply(context: Context, sel: Tree, args: List[Tree]): Aligned = {
       val fn = sel match {
         case Unapplied(fn) => fn
         case _             => sel
@@ -145,12 +146,12 @@ trait ScalacPatternExpanders {
       }
 
       val normalizedExtractor = if (requiresTupling) tupleExtractor(extractor) else extractor
-      validateAligned(fn, Aligned(patterns, normalizedExtractor))
+      validateAligned(context, fn, Aligned(patterns, normalizedExtractor))
     }
 
-    def apply(tree: Tree): Aligned = tree match {
-      case Apply(fn, args)   => apply(fn, args)
-      case UnApply(fn, args) => apply(fn, args)
+    def apply(context: Context, tree: Tree): Aligned = tree match {
+      case Apply(fn, args)   => apply(context, fn, args)
+      case UnApply(fn, args) => apply(context, fn, args)
     }
   }
 }
diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala b/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala
index da0e67a2a5..bb8c3c3c6d 100644
--- a/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala
@@ -309,7 +309,7 @@ trait PatternTypers {
         // the union of the expected type and the inferred type of the argument to unapply
         val glbType        = glb(ensureFullyDefined(pt) :: unapplyArg.tpe_* :: Nil)
         val wrapInTypeTest = canRemedy && !(fun1.symbol.owner isNonBottomSubClass ClassTagClass)
-        val formals        = patmat.alignPatterns(fun1, args).unexpandedFormals
+        val formals        = patmat.alignPatterns(context.asInstanceOf[analyzer.Context], fun1, args).unexpandedFormals
         val args1          = typedArgsForFormals(args, formals, mode)
         val result         = UnApply(fun1, args1) setPos tree.pos setType glbType
 
diff --git a/test/files/pos/t8719.check b/test/files/pos/t8719.check
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/test/files/pos/t8719.check
diff --git a/test/files/pos/t8719/Macros_1.scala b/test/files/pos/t8719/Macros_1.scala
new file mode 100644
index 0000000000..152c92f254
--- /dev/null
+++ b/test/files/pos/t8719/Macros_1.scala
@@ -0,0 +1,21 @@
+import scala.language.experimental.macros
+import scala.reflect.macros.TypecheckException
+import scala.reflect.macros.whitebox.Context
+
+object Macros {
+  def typecheck_impl(c: Context)(code: c.Expr[String]): c.Expr[Option[String]] = {
+    import c.universe._
+
+    val Expr(Literal(Constant(codeStr: String))) = code
+
+    try {
+      c.typecheck(c.parse(codeStr))
+      c.Expr(q"None: Option[String]")
+    } catch {
+      case e: TypecheckException =>
+        c.Expr(q"Some(${ e.toString }): Option[String]")
+    }
+  }
+
+  def typecheck(code: String): Option[String] = macro typecheck_impl
+}
\ No newline at end of file
diff --git a/test/files/pos/t8719/Test_2.scala b/test/files/pos/t8719/Test_2.scala
new file mode 100644
index 0000000000..997eb2f236
--- /dev/null
+++ b/test/files/pos/t8719/Test_2.scala
@@ -0,0 +1,10 @@
+case class Foo(i: Int, c: Char)
+
+object Bar {
+  def unapply(foo: Foo): Option[(Int, Char)] = Some((foo.i, foo.c))
+}
+
+object Test extends App {
+  println(Macros.typecheck("val Foo(x, y, z) = Foo(1, 'a')"))
+  println(Macros.typecheck("val Bar(x, y, z) = Foo(1, 'a')"))
+}
\ No newline at end of file