diff options
Diffstat (limited to 'src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala | 69 |
1 files changed, 64 insertions, 5 deletions
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala index e8e848161c..8477f5461a 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala @@ -9,6 +9,7 @@ package opt import scala.annotation.tailrec import scala.tools.asm +import asm.Handle import asm.Opcodes._ import asm.tree._ import scala.collection.convert.decorateAsScala._ @@ -455,9 +456,9 @@ class Inliner[BT <: BTypes](val btypes: BT) { case indy: InvokeDynamicInsnNode => callGraph.closureInstantiations.get(indy) match { - case Some((methodNode, ownerClass)) => + case Some(closureInit) => val newIndy = instructionMap(indy).asInstanceOf[InvokeDynamicInsnNode] - callGraph.closureInstantiations(newIndy) = (callsiteMethod, callsiteClass) + callGraph.closureInstantiations(newIndy) = ClosureInstantiation(closureInit.lambdaMetaFactoryCall.copy(indy = newIndy), callsiteMethod, callsiteClass) case None => } @@ -687,9 +688,67 @@ class Inliner[BT <: BTypes](val btypes: BT) { } } - case ivd: InvokeDynamicInsnNode => - // TODO @lry check necessary conditions to inline an indy, instead of giving up - Right(false) + case _: InvokeDynamicInsnNode if destinationClass == calleeDeclarationClass => + // within the same class, any indy instruction can be inlined + Right(true) + + // does the InvokeDynamicInsnNode call LambdaMetaFactory? + case LambdaMetaFactoryCall(_, _, implMethod, _) => + // an indy instr points to a "call site specifier" (CSP) [1] + // - a reference to a bootstrap method [2] + // - bootstrap method name + // - references to constant arguments, which can be: + // - constant (string, long, int, float, double) + // - class + // - method type (without name) + // - method handle + // - a method name+type + // + // execution [3] + // - resolve the CSP, yielding the boostrap method handle, the static args and the name+type + // - resolution entails accessibility checking [4] + // - execute the `invoke` method of the boostrap method handle (which is signature polymorphic, check its javadoc) + // - the descriptor for the call is made up from the actual arguments on the stack: + // - the first parameters are "MethodHandles.Lookup, String, MethodType", then the types of the constant arguments, + // - the return type is CallSite + // - the values for the call are + // - the bootstrap method handle of the CSP is the receiver + // - the Lookup object for the class in which the callsite occurs (obtained as through calling MethodHandles.lookup()) + // - the method name of the CSP + // - the method type of the CSP + // - the constants of the CSP (primitives are not boxed) + // - the resulting `CallSite` object + // - has as `type` the method type of the CSP + // - is popped from the operand stack + // - the `invokeExact` method (signature polymorphic!) of the `target` method handle of the CallSite is invoked + // - the method descriptor is that of the CSP + // - the receiver is the target of the CallSite + // - the other argument values are those that were on the operand stack at the indy instruction (indyLambda: the captured values) + // + // [1] http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.4.10 + // [2] http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.23 + // [3] http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.invokedynamic + // [4] http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-5.html#jvms-5.4.3 + + // We cannot generically check if an `invokedynamic` instruction can be safely inlined into + // a different class, that depends on the bootstrap method. The Lookup object passed to the + // bootstrap method is a capability to access private members of the callsite class. We can + // only move the invokedynamic to a new class if we know that the bootstrap method doesn't + // use this capability for otherwise non-accessible members. + // In the case of indyLambda, it depends on the visibility of the implMethod handle. If + // the implMethod is public, lambdaMetaFactory doesn't use the Lookup object's extended + // capability, and we can safely inline the instruction into a different class. + + val methodRefClass = classBTypeFromParsedClassfile(implMethod.getOwner) + for { + (methodNode, methodDeclClassNode) <- byteCodeRepository.methodNode(methodRefClass.internalName, implMethod.getName, implMethod.getDesc): Either[OptimizerWarning, (MethodNode, InternalName)] + methodDeclClass = classBTypeFromParsedClassfile(methodDeclClassNode) + res <- memberIsAccessible(methodNode.access, methodDeclClass, methodRefClass, destinationClass) + } yield { + res + } + + case _: InvokeDynamicInsnNode => Left(UnknownInvokeDynamicInstruction) case ci: LdcInsnNode => ci.cst match { case t: asm.Type => classIsAccessible(bTypeForDescriptorOrInternalNameFromClassfile(t.getInternalName), destinationClass) |