diff options
Diffstat (limited to 'tests/untried/neg-with-implicits/macro-divergence-controlled')
-rw-r--r-- | tests/untried/neg-with-implicits/macro-divergence-controlled/Impls_Macros_1.scala | 23 | ||||
-rw-r--r-- | tests/untried/neg-with-implicits/macro-divergence-controlled/Test_2.scala | 3 |
2 files changed, 26 insertions, 0 deletions
diff --git a/tests/untried/neg-with-implicits/macro-divergence-controlled/Impls_Macros_1.scala b/tests/untried/neg-with-implicits/macro-divergence-controlled/Impls_Macros_1.scala new file mode 100644 index 000000000..5c0450326 --- /dev/null +++ b/tests/untried/neg-with-implicits/macro-divergence-controlled/Impls_Macros_1.scala @@ -0,0 +1,23 @@ +import scala.reflect.macros.whitebox.Context +import language.experimental.macros + +trait Complex[T] + +class Foo(val foo: Foo) + +object Complex { + def impl[T: c.WeakTypeTag](c: Context): c.Expr[Complex[T]] = { + import c.universe._ + val tpe = weakTypeOf[T] + for (f <- tpe.decls.collect{case f: TermSymbol if f.isParamAccessor && !f.isMethod => f}) { + val trecur = appliedType(typeOf[Complex[_]], List(f.info)) + if (c.openImplicits.tail.exists(ic => ic.pt =:= trecur)) c.abort(c.enclosingPosition, "diverging implicit expansion. reported by a macro!") + val recur = c.inferImplicitValue(trecur, silent = true) + if (recur == EmptyTree) c.abort(c.enclosingPosition, s"couldn't synthesize $trecur") + } + c.Expr[Null](q"null") + } + + implicit object ComplexString extends Complex[String] + implicit def genComplex[T]: Complex[T] = macro impl[T] +} diff --git a/tests/untried/neg-with-implicits/macro-divergence-controlled/Test_2.scala b/tests/untried/neg-with-implicits/macro-divergence-controlled/Test_2.scala new file mode 100644 index 000000000..e06175f30 --- /dev/null +++ b/tests/untried/neg-with-implicits/macro-divergence-controlled/Test_2.scala @@ -0,0 +1,3 @@ +object Test extends App { + println(implicitly[Complex[Foo]]) +} |