| // Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| package com.android.tools.r8.ir.optimize.string; |
| |
| import static com.android.tools.r8.ir.optimize.CodeRewriter.removeOrReplaceByDebugLocalWrite; |
| import static com.android.tools.r8.ir.optimize.ReflectionOptimizer.ClassNameComputationInfo.ClassNameComputationOption.CANONICAL_NAME; |
| import static com.android.tools.r8.ir.optimize.ReflectionOptimizer.ClassNameComputationInfo.ClassNameComputationOption.NAME; |
| import static com.android.tools.r8.ir.optimize.ReflectionOptimizer.ClassNameComputationInfo.ClassNameComputationOption.SIMPLE_NAME; |
| import static com.android.tools.r8.ir.optimize.ReflectionOptimizer.computeClassName; |
| import static com.android.tools.r8.utils.DescriptorUtils.INNER_CLASS_SEPARATOR; |
| |
| import com.android.tools.r8.graph.AppInfo; |
| import com.android.tools.r8.graph.DexClass; |
| import com.android.tools.r8.graph.DexItemFactory; |
| import com.android.tools.r8.graph.DexMethod; |
| import com.android.tools.r8.graph.DexType; |
| import com.android.tools.r8.ir.analysis.type.TypeLatticeElement; |
| import com.android.tools.r8.ir.code.BasicBlock.ThrowingInfo; |
| import com.android.tools.r8.ir.code.ConstClass; |
| import com.android.tools.r8.ir.code.ConstNumber; |
| import com.android.tools.r8.ir.code.ConstString; |
| import com.android.tools.r8.ir.code.DexItemBasedConstString; |
| import com.android.tools.r8.ir.code.IRCode; |
| import com.android.tools.r8.ir.code.Instruction; |
| import com.android.tools.r8.ir.code.InstructionIterator; |
| import com.android.tools.r8.ir.code.InvokeStatic; |
| import com.android.tools.r8.ir.code.InvokeVirtual; |
| import com.android.tools.r8.ir.code.Value; |
| import com.android.tools.r8.ir.optimize.ReflectionOptimizer.ClassNameComputationInfo; |
| import com.android.tools.r8.utils.InternalOptions; |
| import java.util.function.BiFunction; |
| import java.util.function.Function; |
| |
| public class StringOptimizer { |
| |
| private final ThrowingInfo throwingInfo; |
| |
| public StringOptimizer(InternalOptions options) { |
| throwingInfo = options.isGeneratingClassFiles() |
| ? ThrowingInfo.NO_THROW : ThrowingInfo.CAN_THROW; |
| } |
| |
| // int String#length() |
| // boolean String#isEmpty() |
| // boolean String#startsWith(str) |
| // boolean String#endsWith(str) |
| // boolean String#contains(str) |
| // boolean String#equals(str) |
| // boolean String#equalsIgnoreCase(str) |
| // boolean String#contentEquals(str) |
| public void computeTrivialOperationsOnConstString(IRCode code, DexItemFactory factory) { |
| if (!code.hasConstString) { |
| return; |
| } |
| InstructionIterator it = code.instructionIterator(); |
| while (it.hasNext()) { |
| Instruction instr = it.next(); |
| if (!instr.isInvokeVirtual()) { |
| continue; |
| } |
| InvokeVirtual invoke = instr.asInvokeVirtual(); |
| DexMethod invokedMethod = invoke.getInvokedMethod(); |
| Function<String, Integer> operatorWithNoArg = null; |
| BiFunction<String, String, Integer> operatorWithString = null; |
| if (invokedMethod == factory.stringMethods.length) { |
| operatorWithNoArg = String::length; |
| } else if (invokedMethod == factory.stringMethods.isEmpty) { |
| operatorWithNoArg = rcv -> rcv.isEmpty() ? 1 : 0; |
| } else if (invokedMethod == factory.stringMethods.contains) { |
| operatorWithString = (rcv, arg) -> rcv.contains(arg) ? 1 : 0; |
| } else if (invokedMethod == factory.stringMethods.startsWith) { |
| operatorWithString = (rcv, arg) -> rcv.startsWith(arg) ? 1 : 0; |
| } else if (invokedMethod == factory.stringMethods.endsWith) { |
| operatorWithString = (rcv, arg) -> rcv.endsWith(arg) ? 1 : 0; |
| } else if (invokedMethod == factory.stringMethods.equals) { |
| operatorWithString = (rcv, arg) -> rcv.equals(arg) ? 1 : 0; |
| } else if (invokedMethod == factory.stringMethods.equalsIgnoreCase) { |
| operatorWithString = (rcv, arg) -> rcv.equalsIgnoreCase(arg) ? 1 : 0; |
| } else if (invokedMethod == factory.stringMethods.contentEqualsCharSequence) { |
| operatorWithString = (rcv, arg) -> rcv.contentEquals(arg) ? 1 : 0; |
| } |
| if (operatorWithNoArg == null && operatorWithString == null) { |
| continue; |
| } |
| Value rcv = invoke.getReceiver().getAliasedValue(); |
| if (rcv.definition == null |
| || !rcv.definition.isConstString() |
| || !rcv.isConstant()) { |
| continue; |
| } |
| if (operatorWithNoArg != null) { |
| assert invoke.inValues().size() == 1; |
| ConstString rcvString = rcv.definition.asConstString(); |
| int v = operatorWithNoArg.apply(rcvString.getValue().toString()); |
| ConstNumber constNumber = code.createIntConstant(v); |
| it.replaceCurrentInstruction(constNumber); |
| } else { |
| assert operatorWithString != null; |
| assert invoke.inValues().size() == 2; |
| Value arg = invoke.inValues().get(1).getAliasedValue(); |
| if (arg.definition == null |
| || !arg.definition.isConstString() |
| || !arg.isConstant()) { |
| continue; |
| } |
| ConstString rcvString = rcv.definition.asConstString(); |
| ConstString argString = arg.definition.asConstString(); |
| int v = operatorWithString.apply( |
| rcvString.getValue().toString(), argString.getValue().toString()); |
| ConstNumber constNumber = code.createIntConstant(v); |
| it.replaceCurrentInstruction(constNumber); |
| } |
| } |
| } |
| |
| // Find Class#get*Name() with a constant-class and replace it with a const-string if possible. |
| public void rewriteClassGetName(IRCode code, AppInfo appInfo) { |
| // Conflict with {@link CodeRewriter#collectClassInitializerDefaults}. |
| if (code.method.isClassInitializer()) { |
| return; |
| } |
| boolean markUseIdentifierNameString = false; |
| InstructionIterator it = code.instructionIterator(); |
| while (it.hasNext()) { |
| Instruction instr = it.next(); |
| if (!instr.isInvokeVirtual()) { |
| continue; |
| } |
| InvokeVirtual invoke = instr.asInvokeVirtual(); |
| DexMethod invokedMethod = invoke.getInvokedMethod(); |
| if (!appInfo.dexItemFactory.classMethods.isReflectiveNameLookup(invokedMethod)) { |
| continue; |
| } |
| assert invoke.inValues().size() == 1; |
| // In case of handling multiple invocations over the same const-string, all the following |
| // usages after the initial one will point to non-null IR (a.k.a. alias), e.g., |
| // |
| // rcv <- invoke-virtual instance, ...#getClass() // Can be rewritten to const-class |
| // x <- invoke-virtual rcv, Class#getName() |
| // non_null_rcv <- non-null rcv |
| // y <- invoke-virtual non_null_rcv, Class#getCanonicalName() |
| // z <- invoke-virtual non_null_rcv, Class#getSimpleName() |
| // ... // or some other usages of the same usage. |
| // |
| // In that case, we should check if the original source is (possibly rewritten) const-class. |
| Value in = invoke.getReceiver().getAliasedValue(); |
| if (in.definition == null |
| || !in.definition.isConstClass() |
| || !in.isConstant()) { |
| continue; |
| } |
| |
| ConstClass constClass = in.definition.asConstClass(); |
| DexType type = constClass.getValue(); |
| int arrayDepth = type.getNumberOfLeadingSquareBrackets(); |
| DexType baseType = type.toBaseType(appInfo.dexItemFactory); |
| // Make sure base type is a class type. |
| if (!baseType.isClassType()) { |
| continue; |
| } |
| DexClass holder = appInfo.definitionFor(baseType); |
| if (holder == null) { |
| continue; |
| } |
| |
| String descriptor = baseType.toDescriptorString(); |
| boolean assumeTopLevel = descriptor.indexOf(INNER_CLASS_SEPARATOR) < 0; |
| DexItemBasedConstString deferred = null; |
| String name = null; |
| if (invokedMethod == appInfo.dexItemFactory.classMethods.getName) { |
| if (code.options.enableMinification) { |
| deferred = new DexItemBasedConstString( |
| invoke.outValue(), baseType, new ClassNameComputationInfo(NAME, arrayDepth)); |
| } else { |
| name = computeClassName(descriptor, holder, NAME, arrayDepth); |
| } |
| } else if (invokedMethod == appInfo.dexItemFactory.classMethods.getTypeName) { |
| // TODO(b/119426668): desugar Type#getTypeName |
| continue; |
| } else if (invokedMethod == appInfo.dexItemFactory.classMethods.getCanonicalName) { |
| // Always returns null if the target type is local or anonymous class. |
| if (holder.isLocalClass() || holder.isAnonymousClass()) { |
| ConstNumber constNull = code.createConstNull(); |
| it.replaceCurrentInstruction(constNull); |
| } else { |
| // b/119471127: If an outer class is shrunk, we may compute a wrong canonical name. |
| // Leave it as-is so that the class's canonical name is consistent across the app. |
| if (!assumeTopLevel) { |
| continue; |
| } |
| if (code.options.enableMinification) { |
| deferred = |
| new DexItemBasedConstString( |
| invoke.outValue(), |
| baseType, |
| new ClassNameComputationInfo(CANONICAL_NAME, arrayDepth)); |
| } else { |
| name = computeClassName(descriptor, holder, CANONICAL_NAME, arrayDepth); |
| } |
| } |
| } else if (invokedMethod == appInfo.dexItemFactory.classMethods.getSimpleName) { |
| // Always returns an empty string if the target type is an anonymous class. |
| if (holder.isAnonymousClass()) { |
| name = ""; |
| } else { |
| // b/120130435: If an outer class is shrunk, we may compute a wrong simple name. |
| // Leave it as-is so that the class's simple name is consistent across the app. |
| if (!assumeTopLevel) { |
| continue; |
| } |
| if (code.options.enableMinification) { |
| deferred = new DexItemBasedConstString( |
| invoke.outValue(), baseType, new ClassNameComputationInfo(SIMPLE_NAME, arrayDepth)); |
| } else { |
| name = computeClassName(descriptor, holder, SIMPLE_NAME, arrayDepth); |
| } |
| } |
| } |
| if (name != null) { |
| Value stringValue = |
| code.createValue(TypeLatticeElement.stringClassType(appInfo), invoke.getLocalInfo()); |
| ConstString constString = |
| new ConstString(stringValue, appInfo.dexItemFactory.createString(name), throwingInfo); |
| it.replaceCurrentInstruction(constString); |
| } else if (deferred != null) { |
| it.replaceCurrentInstruction(deferred); |
| markUseIdentifierNameString = true; |
| } |
| } |
| if (markUseIdentifierNameString) { |
| code.method.getMutableOptimizationInfo().markUseIdentifierNameString(); |
| } |
| } |
| |
| // String#valueOf(null) -> "null" |
| // String#valueOf(String s) -> s |
| // str.toString() -> str |
| public void removeTrivialConversions(IRCode code, AppInfo appInfo) { |
| InstructionIterator it = code.instructionIterator(); |
| while (it.hasNext()) { |
| Instruction instr = it.next(); |
| if (instr.isInvokeStatic()) { |
| InvokeStatic invoke = instr.asInvokeStatic(); |
| DexMethod invokedMethod = invoke.getInvokedMethod(); |
| if (invokedMethod != appInfo.dexItemFactory.stringMethods.valueOf) { |
| continue; |
| } |
| assert invoke.inValues().size() == 1; |
| Value in = invoke.inValues().get(0); |
| if (in.hasLocalInfo()) { |
| continue; |
| } |
| TypeLatticeElement inType = in.getTypeLattice(); |
| if (inType.isConstantNull()) { |
| Value nullStringValue = |
| code.createValue(TypeLatticeElement.stringClassType(appInfo), invoke.getLocalInfo()); |
| ConstString nullString = new ConstString( |
| nullStringValue, appInfo.dexItemFactory.createString("null"), throwingInfo); |
| it.replaceCurrentInstruction(nullString); |
| } else if (inType.nullElement().isDefinitelyNotNull() |
| && inType.isClassType() |
| && inType.asClassTypeLatticeElement().getClassType() |
| .equals(appInfo.dexItemFactory.stringType)) { |
| Value out = invoke.outValue(); |
| if (out != null) { |
| removeOrReplaceByDebugLocalWrite(invoke, it, in, out); |
| } else { |
| it.removeOrReplaceByDebugLocalRead(); |
| } |
| } |
| } else if (instr.isInvokeVirtual()) { |
| InvokeVirtual invoke = instr.asInvokeVirtual(); |
| DexMethod invokedMethod = invoke.getInvokedMethod(); |
| if (invokedMethod != appInfo.dexItemFactory.stringMethods.toString) { |
| continue; |
| } |
| assert invoke.inValues().size() == 1; |
| Value in = invoke.getReceiver(); |
| TypeLatticeElement inType = in.getTypeLattice(); |
| if (inType.nullElement().isDefinitelyNotNull() |
| && inType.isClassType() |
| && inType.asClassTypeLatticeElement().getClassType() |
| .equals(appInfo.dexItemFactory.stringType)) { |
| Value out = invoke.outValue(); |
| if (out != null) { |
| removeOrReplaceByDebugLocalWrite(invoke, it, in, out); |
| } else { |
| it.removeOrReplaceByDebugLocalRead(); |
| } |
| } |
| } |
| } |
| } |
| |
| } |
