From 0533a3df71e9c855ac68e10d060c2c87d16994e0 Mon Sep 17 00:00:00 2001 From: Jason Zaugg Date: Wed, 4 May 2016 21:16:41 +1000 Subject: Lambda impl methods static and more stably named The body of lambdas is compiled into a synthetic method in the enclosing class. Previously, this method was a public virtual method named `fully$qualified$Class$$anonfun$n`. For lambdas that didn't capture a `this` reference, a static method was used. This commit changes two aspects. Firstly, all lambda impl methods are now emitted static. An extra parameter is added to those that require a this reference. This is an improvement as it: - allows, shorter, more readable names for the lambda impl method - avoids pollution of the vtable of the class. Note that javac uses private instance methods, rather than public static methods. If we followed its lead, we would be unable to support important use cases in our inliner Secondly, the name of the enclosing method has been included in the name of the lambda impl method to improve debuggability and to improve serialization compatibility. The serialization improvement comes from the way that fresh names for the impl methods are allocated: adding or removing lambdas in methods not named "foo" won't change the numbering of the `anonfun$foo$n` impl methods from methods named "foo". This is in line with user expectations about anonymous class and lambda serialization stability. Brian Goetz has described this tricky area well in: http://cr.openjdk.java.net/~briangoetz/eg-attachments/lambda-serialization.html This commit doesn't go as far a Javac, we don't use the hash of the lambda type info, param names, etc to map to a lambda impl method name. As such, we are more prone to the type-1 and -2 failures described there. However, our Scala 2.11.8 has similar characteristics, so we aren't going backwards. Special case in the naming: Use "new" rather than "" for constructor enclosed lambdas, as javac does. I have also changed the way that "delambdafy target" methods are identifed. Rather than relying on the naming convention, I have switched to using a symbol attachment. The assumption is that we only need to identify them from within the same compilation unit. This means we can distinguish impl metbods for expanded functions (ones called from an `apply` method of an ahead-of-time expanded anonfun class), from those that truly end up as targets for lambda metafactory. Only the latter are translated to static methods in this patch. --- src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/compiler/scala/tools/nsc/backend/jvm') diff --git a/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala b/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala index f94642389d..6d3c3f3863 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala @@ -121,7 +121,7 @@ class BackendUtils[BT <: BTypes](val btypes: BT) { def getBoxedUnit: FieldInsnNode = new FieldInsnNode(GETSTATIC, srBoxedUnitRef.internalName, "UNIT", srBoxedUnitRef.descriptor) - private val anonfunAdaptedName = """.*\$anonfun\$\d+\$adapted""".r + private val anonfunAdaptedName = """.*\$anonfun\$.*\$\d+\$adapted""".r def hasAdaptedImplMethod(closureInit: ClosureInstantiation): Boolean = { isBuiltinFunctionType(Type.getReturnType(closureInit.lambdaMetaFactoryCall.indy.desc).getInternalName) && anonfunAdaptedName.pattern.matcher(closureInit.lambdaMetaFactoryCall.implMethod.getName).matches -- cgit v1.2.3 From f01d061caaae26b3fdff0e4db800292e9b3252c2 Mon Sep 17 00:00:00 2001 From: Lukas Rytz Date: Fri, 13 May 2016 13:43:13 +0200 Subject: Treat self parameter as non-null in the optimizer --- src/compiler/scala/tools/nsc/ast/TreeGen.scala | 2 +- .../nsc/backend/jvm/analysis/NullnessAnalyzer.scala | 16 +++++++++++----- .../scala/tools/nsc/backend/jvm/opt/CallGraph.scala | 2 +- .../scala/tools/nsc/backend/jvm/opt/LocalOpt.scala | 2 +- .../tools/nsc/backend/jvm/OptimizedBytecodeTest.scala | 2 +- .../nsc/backend/jvm/analysis/NullnessAnalyzerTest.scala | 2 +- 6 files changed, 16 insertions(+), 10 deletions(-) (limited to 'src/compiler/scala/tools/nsc/backend/jvm') diff --git a/src/compiler/scala/tools/nsc/ast/TreeGen.scala b/src/compiler/scala/tools/nsc/ast/TreeGen.scala index 3dff4a02c9..80a707461c 100644 --- a/src/compiler/scala/tools/nsc/ast/TreeGen.scala +++ b/src/compiler/scala/tools/nsc/ast/TreeGen.scala @@ -344,7 +344,7 @@ abstract class TreeGen extends scala.reflect.internal.TreeGen with TreeDSL { val newSym = maybeClone(orig.symbol) newSym.setFlag(STATIC) // Add an explicit self parameter - val selfParamSym = newSym.newSyntheticValueParam(newSym.owner.typeConstructor, nme.SELF) + val selfParamSym = newSym.newSyntheticValueParam(newSym.owner.typeConstructor, nme.SELF).setFlag(ARTIFACT) newSym.updateInfo(newSym.info match { case mt @ MethodType(params, res) => copyMethodType(mt, selfParamSym :: params, res) }) diff --git a/src/compiler/scala/tools/nsc/backend/jvm/analysis/NullnessAnalyzer.scala b/src/compiler/scala/tools/nsc/backend/jvm/analysis/NullnessAnalyzer.scala index 30e73f8ac2..01afd0d2ef 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/analysis/NullnessAnalyzer.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/analysis/NullnessAnalyzer.scala @@ -5,8 +5,8 @@ package analysis import java.util import scala.annotation.switch -import scala.tools.asm.{Type, Opcodes} -import scala.tools.asm.tree.{MethodInsnNode, LdcInsnNode, AbstractInsnNode} +import scala.tools.asm.{Opcodes, Type} +import scala.tools.asm.tree.{AbstractInsnNode, LdcInsnNode, MethodInsnNode, MethodNode} import scala.tools.asm.tree.analysis._ import scala.tools.nsc.backend.jvm.opt.BytecodeUtils import BytecodeUtils._ @@ -63,7 +63,7 @@ object NullnessValue { def unknown(insn: AbstractInsnNode) = if (BytecodeUtils.instructionResultSize(insn) == 2) UnknownValue2 else UnknownValue1 } -final class NullnessInterpreter(bTypes: BTypes) extends Interpreter[NullnessValue](Opcodes.ASM5) { +final class NullnessInterpreter(bTypes: BTypes, method: MethodNode) extends Interpreter[NullnessValue](Opcodes.ASM5) { def newValue(tp: Type): NullnessValue = { // ASM loves giving semantics to null. The behavior here is the same as in SourceInterpreter, // which is provided by the framework. @@ -80,7 +80,13 @@ final class NullnessInterpreter(bTypes: BTypes) extends Interpreter[NullnessValu override def newParameterValue(isInstanceMethod: Boolean, local: Int, tp: Type): NullnessValue = { // For instance methods, the `this` parameter is known to be not null. - if (isInstanceMethod && local == 0) NotNullValue + val isThis = local == 0 && (isInstanceMethod || { + method.parameters != null && !method.parameters.isEmpty && { + val p = method.parameters.get(0) + (p.access & Opcodes.ACC_SYNTHETIC) != 0 && p.name == "$this" + } + }) + if (isThis) NotNullValue else super.newParameterValue(isInstanceMethod, local, tp) } @@ -197,7 +203,7 @@ class NullnessFrame(nLocals: Int, nStack: Int) extends AliasingFrame[NullnessVal * This class is required to override the `newFrame` methods, which makes makes sure the analyzer * uses NullnessFrames. */ -class NullnessAnalyzer(bTypes: BTypes) extends Analyzer[NullnessValue](new NullnessInterpreter(bTypes)) { +class NullnessAnalyzer(bTypes: BTypes, method: MethodNode) extends Analyzer[NullnessValue](new NullnessInterpreter(bTypes, method)) { override def newFrame(nLocals: Int, nStack: Int): NullnessFrame = new NullnessFrame(nLocals, nStack) override def newFrame(src: Frame[_ <: NullnessValue]): NullnessFrame = new NullnessFrame(src) } diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala index e8d1bf203a..d4ff6493a3 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala @@ -103,7 +103,7 @@ class CallGraph[BT <: BTypes](val btypes: BT) { val analyzer = { if (compilerSettings.optNullnessTracking && AsmAnalyzer.sizeOKForNullness(methodNode)) { - Some(new AsmAnalyzer(methodNode, definingClass.internalName, new NullnessAnalyzer(btypes))) + Some(new AsmAnalyzer(methodNode, definingClass.internalName, new NullnessAnalyzer(btypes, methodNode))) } else if (AsmAnalyzer.sizeOKForBasicValue(methodNode)) { Some(new AsmAnalyzer(methodNode, definingClass.internalName)) } else None diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala index 5ca0ad2773..447ee209b5 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala @@ -397,7 +397,7 @@ class LocalOpt[BT <: BTypes](val btypes: BT) { */ def nullnessOptimizations(method: MethodNode, ownerClassName: InternalName): Boolean = { AsmAnalyzer.sizeOKForNullness(method) && { - lazy val nullnessAnalyzer = new AsmAnalyzer(method, ownerClassName, new NullnessAnalyzer(btypes)) + lazy val nullnessAnalyzer = new AsmAnalyzer(method, ownerClassName, new NullnessAnalyzer(btypes, method)) // When running nullness optimizations the method may still have unreachable code. Analyzer // frames of unreachable instructions are `null`. diff --git a/test/junit/scala/tools/nsc/backend/jvm/OptimizedBytecodeTest.scala b/test/junit/scala/tools/nsc/backend/jvm/OptimizedBytecodeTest.scala index b64a5ae3ce..9a0899ffc5 100644 --- a/test/junit/scala/tools/nsc/backend/jvm/OptimizedBytecodeTest.scala +++ b/test/junit/scala/tools/nsc/backend/jvm/OptimizedBytecodeTest.scala @@ -44,7 +44,7 @@ class OptimizedBytecodeTest extends BytecodeTesting { assertSameSummary(getMethod(c, "t"), List( LDC, ASTORE, ALOAD /*0*/, ALOAD /*1*/, "$anonfun$t$1", IRETURN)) - assertSameSummary(getMethod(c, "$anonfun$t$1"), List(ALOAD, IFNONNULL, ACONST_NULL, ATHROW, -1, LDC, "$anonfun$t$2", IRETURN)) + assertSameSummary(getMethod(c, "$anonfun$t$1"), List(LDC, "$anonfun$t$2", IRETURN)) assertSameSummary(getMethod(c, "$anonfun$t$2"), List(-1 /*A*/, GOTO /*A*/)) } diff --git a/test/junit/scala/tools/nsc/backend/jvm/analysis/NullnessAnalyzerTest.scala b/test/junit/scala/tools/nsc/backend/jvm/analysis/NullnessAnalyzerTest.scala index 1de5aa28ca..c173bacd46 100644 --- a/test/junit/scala/tools/nsc/backend/jvm/analysis/NullnessAnalyzerTest.scala +++ b/test/junit/scala/tools/nsc/backend/jvm/analysis/NullnessAnalyzerTest.scala @@ -21,7 +21,7 @@ class NullnessAnalyzerTest extends BytecodeTesting { import compiler._ import global.genBCode.bTypes.backendUtils._ - def newNullnessAnalyzer(methodNode: MethodNode, classInternalName: InternalName = "C") = new AsmAnalyzer(methodNode, classInternalName, new NullnessAnalyzer(global.genBCode.bTypes)) + def newNullnessAnalyzer(methodNode: MethodNode, classInternalName: InternalName = "C") = new AsmAnalyzer(methodNode, classInternalName, new NullnessAnalyzer(global.genBCode.bTypes, methodNode)) def testNullness(analyzer: AsmAnalyzer[NullnessValue], method: MethodNode, query: String, index: Int, nullness: NullnessValue): Unit = { for (i <- findInstrs(method, query)) { -- cgit v1.2.3