diff options
Diffstat (limited to 'src/proguard/optimize/info/SideEffectInstructionChecker.java')
-rw-r--r-- | src/proguard/optimize/info/SideEffectInstructionChecker.java | 109 |
1 files changed, 65 insertions, 44 deletions
diff --git a/src/proguard/optimize/info/SideEffectInstructionChecker.java b/src/proguard/optimize/info/SideEffectInstructionChecker.java index 8be9dc1..1444e5a 100644 --- a/src/proguard/optimize/info/SideEffectInstructionChecker.java +++ b/src/proguard/optimize/info/SideEffectInstructionChecker.java @@ -2,7 +2,7 @@ * ProGuard -- shrinking, optimization, obfuscation, and preverification * of Java bytecode. * - * Copyright (c) 2002-2009 Eric Lafortune (eric@graphics.cornell.edu) + * Copyright (c) 2002-2011 Eric Lafortune (eric@graphics.cornell.edu) * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free @@ -29,11 +29,14 @@ import proguard.classfile.instruction.visitor.InstructionVisitor; import proguard.classfile.util.SimplifiedVisitor; import proguard.classfile.visitor.*; +import java.util.*; + /** * This class can tell whether an instruction has any side effects. Return * instructions can be included or not. * * @see ReadWriteFieldMarker + * @see StaticInitializerContainingClassMarker * @see NoSideEffectMethodMarker * @see SideEffectMethodMarker * @author Eric Lafortune @@ -47,6 +50,7 @@ implements InstructionVisitor, private final boolean includeReturnInstructions; // A return value for the visitor methods. + private Clazz referencingClass; private boolean hasSideEffects; @@ -60,7 +64,7 @@ implements InstructionVisitor, { hasSideEffects = false; - instruction.accept(clazz, method, codeAttribute, offset, this); + instruction.accept(clazz, method, codeAttribute, offset, this); return hasSideEffects; } @@ -118,14 +122,16 @@ implements InstructionVisitor, public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ConstantInstruction constantInstruction) { byte opcode = constantInstruction.opcode; - // Check for instructions that might cause side effects. - if (opcode == InstructionConstants.OP_PUTSTATIC || - opcode == InstructionConstants.OP_PUTFIELD || - opcode == InstructionConstants.OP_INVOKEVIRTUAL || - opcode == InstructionConstants.OP_INVOKESPECIAL || - opcode == InstructionConstants.OP_INVOKESTATIC || - opcode == InstructionConstants.OP_INVOKEINTERFACE) + if (opcode == InstructionConstants.OP_GETSTATIC || + opcode == InstructionConstants.OP_PUTSTATIC || + opcode == InstructionConstants.OP_GETFIELD || + opcode == InstructionConstants.OP_PUTFIELD || + opcode == InstructionConstants.OP_INVOKEVIRTUAL || + opcode == InstructionConstants.OP_INVOKESPECIAL || + opcode == InstructionConstants.OP_INVOKESTATIC || + opcode == InstructionConstants.OP_INVOKEINTERFACE || + opcode == InstructionConstants.OP_INVOKEDYNAMIC) { // Check if the field is write-only or volatile, or if the invoked // method is causing any side effects. @@ -150,48 +156,36 @@ implements InstructionVisitor, // Implementations for ConstantVisitor. + public void visitInvokeDynamicConstant(Clazz clazz, InvokeDynamicConstant invokeDynamicConstant) + { + // We'll have to assume invoking an unknown method has side effects. + hasSideEffects = true; + } + + public void visitFieldrefConstant(Clazz clazz, FieldrefConstant fieldrefConstant) { + // Pass the referencing class. + referencingClass = clazz; + // We'll have to assume accessing an unknown field has side effects. hasSideEffects = true; - // Check the referenced field. + // Check the referenced field, if known. fieldrefConstant.referencedMemberAccept(this); } public void visitAnyMethodrefConstant(Clazz clazz, RefConstant refConstant) { - Member referencedMember = refConstant.referencedMember; + // Pass the referencing class. + referencingClass = clazz; - // Do we have a reference to the method? - if (referencedMember == null) - { - // We'll have to assume invoking the unknown method has side effects. - hasSideEffects = true; - } - else - { - // First check the referenced method itself. - refConstant.referencedMemberAccept(this); - - // If the result isn't conclusive, check down the hierarchy. - if (!hasSideEffects) - { - Clazz referencedClass = refConstant.referencedClass; - Method referencedMethod = (Method)referencedMember; - - // Check all other implementations of the method down the class - // hierarchy. - if ((referencedMethod.getAccessFlags() & ClassConstants.INTERNAL_ACC_PRIVATE) == 0) - { - clazz.hierarchyAccept(false, false, false, true, - new NamedMethodVisitor(referencedMethod.getName(referencedClass), - referencedMethod.getDescriptor(referencedClass), - this)); - } - } - } + // We'll have to assume invoking an unknown method has side effects. + hasSideEffects = true; + + // Check the referenced method, if known. + refConstant.referencedMemberAccept(this); } @@ -199,14 +193,24 @@ implements InstructionVisitor, public void visitProgramField(ProgramClass programClass, ProgramField programField) { - hasSideEffects = ReadWriteFieldMarker.isRead(programField); + hasSideEffects = + (ReadWriteFieldMarker.isRead(programField) && + ReadWriteFieldMarker.isWritten(programField)) || + ((programField.getAccessFlags() & ClassConstants.INTERNAL_ACC_VOLATILE) != 0) || + (!programClass.equals(referencingClass) && + !initializedSuperClasses(referencingClass).containsAll(initializedSuperClasses(programClass))); } public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) { - hasSideEffects = hasSideEffects || - SideEffectMethodMarker.hasSideEffects(programMethod); + // Note that side effects already include synchronization of some + // implementation of the method. + hasSideEffects = + !NoSideEffectMethodMarker.hasNoSideEffects(programMethod) && + (SideEffectMethodMarker.hasSideEffects(programMethod) || + (!programClass.equals(referencingClass) && + !initializedSuperClasses(referencingClass).containsAll(initializedSuperClasses(programClass)))); } @@ -218,7 +222,24 @@ implements InstructionVisitor, public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod) { - hasSideEffects = hasSideEffects || - !NoSideEffectMethodMarker.hasNoSideEffects(libraryMethod); + hasSideEffects = + !NoSideEffectMethodMarker.hasNoSideEffects(libraryMethod); + } + + + /** + * Returns the set of superclasses and interfaces that are initialized. + */ + private Set initializedSuperClasses(Clazz clazz) + { + Set set = new HashSet(); + + // Visit all superclasses and interfaces, collecting the ones that have + // static initializers. + clazz.hierarchyAccept(true, true, true, false, + new StaticInitializerContainingClassFilter( + new ClassCollector(set))); + + return set; } } |