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author | Lukas Rytz <lukas.rytz@gmail.com> | 2015-07-03 08:25:30 +0200 |
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committer | Lukas Rytz <lukas.rytz@gmail.com> | 2015-07-03 10:45:02 +0200 |
commit | 0f3505421cd49d20d948808248266998dfc36867 (patch) | |
tree | aabd326d8306e95470217d61a18e75717d329e46 /src | |
parent | 055a373802a34ee09fc0ed20b2b25c3fa20507d4 (diff) | |
download | scala-0f3505421cd49d20d948808248266998dfc36867.tar.gz scala-0f3505421cd49d20d948808248266998dfc36867.tar.bz2 scala-0f3505421cd49d20d948808248266998dfc36867.zip |
Prevent infinite recursion in ProdConsAnalyzer
When an instruction is its own producer or consumer, the
`initialProducer` / `ultimateConsumer` methods would loop.
While loops or @tailrec annotated methods can generate such bytecode.
Diffstat (limited to 'src')
-rw-r--r-- | src/compiler/scala/tools/nsc/backend/jvm/AsmUtils.scala | 18 | ||||
-rw-r--r-- | src/compiler/scala/tools/nsc/backend/jvm/analysis/ProdConsAnalyzer.scala | 12 |
2 files changed, 21 insertions, 9 deletions
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/AsmUtils.scala b/src/compiler/scala/tools/nsc/backend/jvm/AsmUtils.scala index 0df1b2029d..cd7e0b83e8 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/AsmUtils.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/AsmUtils.scala @@ -10,6 +10,7 @@ import java.io.{StringWriter, PrintWriter} import scala.tools.asm.util.{CheckClassAdapter, TraceClassVisitor, TraceMethodVisitor, Textifier} import scala.tools.asm.{ClassWriter, Attribute, ClassReader} import scala.collection.convert.decorateAsScala._ +import scala.tools.nsc.backend.jvm.analysis.InitialProducer import scala.tools.nsc.backend.jvm.opt.InlineInfoAttributePrototype object AsmUtils { @@ -81,13 +82,16 @@ object AsmUtils { /** * Returns a human-readable representation of the given instruction. */ - def textify(insn: AbstractInsnNode): String = { - val trace = new TraceMethodVisitor(new Textifier) - insn.accept(trace) - val sw = new StringWriter - val pw = new PrintWriter(sw) - trace.p.print(pw) - sw.toString.trim + def textify(insn: AbstractInsnNode): String = insn match { + case _: InitialProducer => + insn.toString + case _ => + val trace = new TraceMethodVisitor(new Textifier) + insn.accept(trace) + val sw = new StringWriter + val pw = new PrintWriter(sw) + trace.p.print(pw) + sw.toString.trim } /** diff --git a/src/compiler/scala/tools/nsc/backend/jvm/analysis/ProdConsAnalyzer.scala b/src/compiler/scala/tools/nsc/backend/jvm/analysis/ProdConsAnalyzer.scala index ad75363102..5d56861ffc 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/analysis/ProdConsAnalyzer.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/analysis/ProdConsAnalyzer.scala @@ -103,7 +103,11 @@ class ProdConsAnalyzer(methodNode: MethodNode, classInternalName: InternalName) def initialProducersForValueAt(insn: AbstractInsnNode, slot: Int): Set[AbstractInsnNode] = { def initialProducers(insn: AbstractInsnNode, producedSlot: Int): Set[AbstractInsnNode] = { if (isCopyOperation(insn)) { - _initialProducersCache.getOrElseUpdate((insn, producedSlot), { + val key = (insn, producedSlot) + _initialProducersCache.getOrElseUpdate(key, { + // prevent infinite recursion if an instruction is its own producer or consumer + // see cyclicProdCons in ProdConsAnalyzerTest + _initialProducersCache(key) = Set.empty val (sourceValue, sourceValueSlot) = copyOperationSourceValue(insn, producedSlot) sourceValue.insns.iterator.asScala.flatMap(initialProducers(_, sourceValueSlot)).toSet }) @@ -121,7 +125,11 @@ class ProdConsAnalyzer(methodNode: MethodNode, classInternalName: InternalName) def ultimateConsumersOfValueAt(insn: AbstractInsnNode, slot: Int): Set[AbstractInsnNode] = { def ultimateConsumers(insn: AbstractInsnNode, consumedSlot: Int): Set[AbstractInsnNode] = { if (isCopyOperation(insn)) { - _ultimateConsumersCache.getOrElseUpdate((insn, consumedSlot), { + val key = (insn, consumedSlot) + _ultimateConsumersCache.getOrElseUpdate(key, { + // prevent infinite recursion if an instruction is its own producer or consumer + // see cyclicProdCons in ProdConsAnalyzerTest + _ultimateConsumersCache(key) = Set.empty for { producedSlot <- copyOperationProducedValueSlots(insn, consumedSlot) consumer <- consumersOfValueAt(insn.getNext, producedSlot) |