SI-6814 adds typechecker modes to c.typecheck

As per multiple user requests, this commit introduces a shortcut
to typecheck trees under multiple different modes: terms (EXPRmode,
was exposed in Scala 2.10) and types (TYPEmode).

Looking into the rest of a dozen of internal typechecker modes, to the
best of my knowledge, I can’t find other modes that we could expose.
FUNmode is useful, but very situational. PATTERNmode is useful, but
also situational, because we don’t expand macros inside patterns
except for whitebox extractor macros. The rest (e.g. POLYmode or TAPPmode)
are too low-level.

1 files changed, 9 insertions, 4 deletions

diff --git a/src/compiler/scala/tools/reflect/ToolBoxFactory.scala b/src/compiler/scala/tools/reflect/ToolBoxFactory.scala
index 7bae3203c2..b43b4653eb 100644
--- a/src/compiler/scala/tools/reflect/ToolBoxFactory.scala
+++ b/src/compiler/scala/tools/reflect/ToolBoxFactory.scala
@@ -171,11 +171,11 @@ abstract class ToolBoxFactory[U <: JavaUniverse](val u: U) { factorySelf =>
         unwrapped
       }
 
-      def typecheck(expr: Tree, pt: Type, silent: Boolean, withImplicitViewsDisabled: Boolean, withMacrosDisabled: Boolean): Tree =
+      def typecheck(expr: Tree, pt: Type, mode: scala.reflect.internal.Mode, silent: Boolean, withImplicitViewsDisabled: Boolean, withMacrosDisabled: Boolean): Tree =
         transformDuringTyper(expr, withImplicitViewsDisabled = withImplicitViewsDisabled, withMacrosDisabled = withMacrosDisabled)(
           (currentTyper, expr) => {
             trace("typing (implicit views = %s, macros = %s): ".format(!withImplicitViewsDisabled, !withMacrosDisabled))(showAttributed(expr, true, true, settings.Yshowsymkinds.value))
-            currentTyper.silent(_.typed(expr, pt), reportAmbiguousErrors = false) match {
+            currentTyper.silent(_.typed(expr, mode, pt), reportAmbiguousErrors = false) match {
               case analyzer.SilentResultValue(result) =>
                 trace("success: ")(showAttributed(result, true, true, settings.Yshowsymkinds.value))
                 result
@@ -361,7 +361,12 @@ abstract class ToolBoxFactory[U <: JavaUniverse](val u: U) { factorySelf =>
       }
     }
 
-    def typecheck(tree: u.Tree, expectedType: u.Type, silent: Boolean = false, withImplicitViewsDisabled: Boolean = false, withMacrosDisabled: Boolean = false): u.Tree = withCompilerApi { compilerApi =>
+    type TypecheckMode = scala.reflect.internal.Mode
+    val TypecheckMode = scala.reflect.internal.Mode
+    val TERMmode = TypecheckMode.EXPRmode
+    val TYPEmode = TypecheckMode.TYPEmode | TypecheckMode.FUNmode
+
+    def typecheck(tree: u.Tree, mode: TypecheckMode = TERMmode, expectedType: u.Type, silent: Boolean = false, withImplicitViewsDisabled: Boolean = false, withMacrosDisabled: Boolean = false): u.Tree = withCompilerApi { compilerApi =>
       import compilerApi._
 
       if (compiler.settings.verbose) println("importing "+tree+", expectedType = "+expectedType)
@@ -369,7 +374,7 @@ abstract class ToolBoxFactory[U <: JavaUniverse](val u: U) { factorySelf =>
       val cexpectedType: compiler.Type = importer.importType(expectedType)
 
       if (compiler.settings.verbose) println("typing "+ctree+", expectedType = "+expectedType)
-      val ttree: compiler.Tree = compiler.typecheck(ctree, cexpectedType, silent = silent, withImplicitViewsDisabled = withImplicitViewsDisabled, withMacrosDisabled = withMacrosDisabled)
+      val ttree: compiler.Tree = compiler.typecheck(ctree, cexpectedType, mode, silent = silent, withImplicitViewsDisabled = withImplicitViewsDisabled, withMacrosDisabled = withMacrosDisabled)
       val uttree = exporter.importTree(ttree)
       uttree
     }