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Refine @compileTimeOnly

 - Don't default the message, and show it exclusively.
 - Fix cut-and-pasto in the @since tag
 - Be tolerant if the annotaion class is missing, as seems to
   have been the case compiling the continuations plugin.
 - s/\t/  / in the test file to show the errors are positioned
   correctly.
 - Use defensive getOrElse
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1 parent 6902da3 commit 48ee29aa26e4e5358cb1de7890565095420177b4 @retronym retronym committed Nov 6, 2012
@@ -1377,8 +1377,13 @@ abstract class RefChecks extends InfoTransform with scala.reflect.internal.trans
}
private def checkCompileTimeOnly(sym: Symbol, pos: Position) = {
- if (sym.isCompileTimeOnly)
- unit.error(pos, s"reference to ${sym.fullLocationString} should not survive typechecking: ${sym.compileTimeOnlyMessage.get}")
+ if (sym.isCompileTimeOnly) {
+ def defaultMsg =
+ s"""|Reference to ${sym.fullLocationString} should not have survived past type checking,
+ |it should have been processed and eliminated during expansion of an enclosing macro.""".stripMargin
+ // The getOrElse part should never happen, it's just here as a backstop.
+ unit.error(pos, sym.compileTimeOnlyMessage getOrElse defaultMsg)
+ }
}
private def lessAccessible(otherSym: Symbol, memberSym: Symbol): Boolean = (
@@ -944,7 +944,7 @@ trait Definitions extends api.StandardDefinitions {
lazy val BeanPropertyAttr = requiredClass[scala.beans.BeanProperty]
lazy val BooleanBeanPropertyAttr = requiredClass[scala.beans.BooleanBeanProperty]
lazy val CloneableAttr = requiredClass[scala.annotation.cloneable]
- lazy val CompileTimeOnlyAttr = requiredClass[scala.reflect.macros.compileTimeOnly]
+ lazy val CompileTimeOnlyAttr = getClassIfDefined("scala.reflect.macros.compileTimeOnly")
lazy val DeprecatedAttr = requiredClass[scala.deprecated]
lazy val DeprecatedNameAttr = requiredClass[scala.deprecatedName]
lazy val DeprecatedInheritanceAttr = requiredClass[scala.deprecatedInheritance]
@@ -10,7 +10,7 @@ import scala.annotation.meta._
*
* @param message the error message to print during compilation if a reference remains
* after type checking
- * @since 2.10.0
+ * @since 2.10.1
*/
@getter @setter @beanGetter @beanSetter
-final class compileTimeOnly(message: String = "") extends scala.annotation.StaticAnnotation
+final class compileTimeOnly(message: String) extends scala.annotation.StaticAnnotation
View
@@ -1,10 +1,10 @@
-Test_2.scala:2: error: reference to method cto in object M should not survive typechecking: cto may only be used as an argument to m
- M.cto // error
- ^
-Test_2.scala:3: error: reference to method cto in object M should not survive typechecking: cto may only be used as an argument to m
- M.m(M.cto, ()) // error
- ^
-Test_2.scala:5: error: reference to method cto in object M should not survive typechecking: cto may only be used as an argument to m
- M.cto // error
- ^
+Test_2.scala:2: error: cto may only be used as an argument to m
+ M.cto // error
+ ^
+Test_2.scala:3: error: cto may only be used as an argument to m
+ M.m(M.cto, ()) // error
+ ^
+Test_2.scala:5: error: cto may only be used as an argument to m
+ M.cto // error
+ ^
three errors found
@@ -2,9 +2,9 @@ import language.experimental.macros
import reflect.macros.Context
object M {
- def m(a: Any, b: Any): Any = macro mImpl
- def mImpl(c: Context)(a: c.Expr[Any], b: c.Expr[Any]) = a
+ def m(a: Any, b: Any): Any = macro mImpl
+ def mImpl(c: Context)(a: c.Expr[Any], b: c.Expr[Any]) = a
- @reflect.macros.compileTimeOnly("cto may only be used as an argument to m")
- def cto = 0
+ @reflect.macros.compileTimeOnly("cto may only be used as an argument to " + "m")
+ def cto = 0
}
@@ -1,6 +1,6 @@
object Test {
- M.cto // error
- M.m(M.cto, ()) // error
- M.m((), M.cto) // okay
- M.cto // error
-}
+ M.cto // error
+ M.m(M.cto, ()) // error
+ M.m((), M.cto) // okay
+ M.cto // error
+}

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