diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/RefChecks.scala | 8 | ||||
| -rw-r--r-- | test/files/pos/t8152-performance.scala | 13 |
2 files changed, 18 insertions, 3 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala index 081f7a8696..fea234dd14 100644 --- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala +++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala @@ -909,11 +909,13 @@ abstract class RefChecks extends InfoTransform with scala.reflect.internal.trans // case DeBruijnIndex(_, _) => case SingleType(pre, sym) => validateVariance(pre, variance) + case TypeRef(_, sym, _) if sym.isAliasType => + // okay to ignore pre/args here. In 2.10.3 we used to check them in addition to checking + // the normalized type, which led to exponential time type checking, see pos/t8152-performance.scala + validateVariance(tp.normalize, variance) case TypeRef(pre, sym, args) => // println("validate "+sym+" at "+relativeVariance(sym)) - if (sym.isAliasType/* && relativeVariance(sym) == AnyVariance*/) - validateVariance(tp.normalize, variance) - else if (sym.variance != NoVariance) { + if (sym.variance != NoVariance) { val v = relativeVariance(sym) if (v != AnyVariance && sym.variance != v * variance) { //Console.println("relativeVariance(" + base + "," + sym + ") = " + v);//DEBUG diff --git a/test/files/pos/t8152-performance.scala b/test/files/pos/t8152-performance.scala new file mode 100644 index 0000000000..b6d2ecd823 --- /dev/null +++ b/test/files/pos/t8152-performance.scala @@ -0,0 +1,13 @@ +class HListBench { + + class A[H, T] + + type B[H, T] = A[H, T] + + // was okay + type T1 = A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, A[Int, Nothing]]]]]]]]]]]]]]]]]]]]]]]]]]]] + + // Took over a minute to validate variance in 2.10.3! + type T2 = B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, B[Int, Nothing]]]]]]]]]]]]]]]]]]]]]]]]]]]] + +}
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