diff options
Diffstat (limited to 'src/proguard/optimize/info/SideEffectInstructionChecker.java')
| -rw-r--r-- | src/proguard/optimize/info/SideEffectInstructionChecker.java | 108 |
1 files changed, 88 insertions, 20 deletions
diff --git a/src/proguard/optimize/info/SideEffectInstructionChecker.java b/src/proguard/optimize/info/SideEffectInstructionChecker.java index 91f1f02..49a1281 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) 2002-2013 Eric Lafortune (eric@graphics.cornell.edu) + * Copyright (c) 2002-2014 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 @@ -33,7 +33,8 @@ import java.util.*; /** * This class can tell whether an instruction has any side effects outside of - * its method. Return instructions can be included or not. + * its method. Return instructions and local field accesses can be included or + * not. * * @see ReadWriteFieldMarker * @see StaticInitializerContainingClassMarker @@ -47,17 +48,25 @@ implements InstructionVisitor, ConstantVisitor, MemberVisitor { - private static final boolean OPTIMIZE_CONSERVATIVELY = System.getProperty("optimize.conservatively") != null; + static final boolean OPTIMIZE_CONSERVATIVELY = System.getProperty("optimize.conservatively") != null; private final boolean includeReturnInstructions; private final boolean includeLocalFieldAccess; // A return value for the visitor methods. + private boolean writingField; private Clazz referencingClass; private boolean hasSideEffects; + /** + * Creates a new SideEffectInstructionChecker + * @param includeReturnInstructions specifies whether return instructions + * count as side effects. + * @param includeLocalFieldAccess specifies whether reading or writing + * local fields counts as side effects. + */ public SideEffectInstructionChecker(boolean includeReturnInstructions, boolean includeLocalFieldAccess) { @@ -96,6 +105,10 @@ implements InstructionVisitor, // Check for instructions that might cause side effects. switch (opcode) { + case InstructionConstants.OP_IDIV: + case InstructionConstants.OP_LDIV: + case InstructionConstants.OP_IREM: + case InstructionConstants.OP_LREM: case InstructionConstants.OP_IALOAD: case InstructionConstants.OP_LALOAD: case InstructionConstants.OP_FALOAD: @@ -104,8 +117,13 @@ implements InstructionVisitor, case InstructionConstants.OP_BALOAD: case InstructionConstants.OP_CALOAD: case InstructionConstants.OP_SALOAD: + case InstructionConstants.OP_NEWARRAY: + case InstructionConstants.OP_ARRAYLENGTH: + case InstructionConstants.OP_ANEWARRAY: + case InstructionConstants.OP_MULTIANEWARRAY: // These instructions strictly taken may cause a side effect - // (NullPointerException, ArrayIndexOutOfBoundsException). + // (ArithmeticException, NullPointerException, + // ArrayIndexOutOfBoundsException, NegativeArraySizeException). hasSideEffects = OPTIMIZE_CONSERVATIVELY; break; @@ -160,16 +178,53 @@ implements InstructionVisitor, switch (opcode) { case InstructionConstants.OP_GETSTATIC: + // Check if accessing the field might cause any side effects. + writingField = false; + clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this); + break; + case InstructionConstants.OP_PUTSTATIC: - case InstructionConstants.OP_INVOKESPECIAL: - case InstructionConstants.OP_INVOKESTATIC: - // Check if the field is write-only or volatile, or if the - // invoked method is causing any side effects. + // Check if accessing the field might cause any side effects. + writingField = true; clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this); break; case InstructionConstants.OP_GETFIELD: + if (OPTIMIZE_CONSERVATIVELY) + { + // These instructions strictly taken may cause a side effect + // (NullPointerException). + hasSideEffects = true; + } + else + { + // Check if the field is write-only or volatile. + writingField = false; + clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this); + } + break; + case InstructionConstants.OP_PUTFIELD: + if (OPTIMIZE_CONSERVATIVELY) + { + // These instructions strictly taken may cause a side effect + // (NullPointerException). + hasSideEffects = true; + } + else + { + // Check if the field is write-only or volatile. + writingField = true; + clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this); + } + break; + + case InstructionConstants.OP_INVOKESPECIAL: + case InstructionConstants.OP_INVOKESTATIC: + // Check if the invoked method is causing any side effects. + clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this); + break; + case InstructionConstants.OP_INVOKEVIRTUAL: case InstructionConstants.OP_INVOKEINTERFACE: case InstructionConstants.OP_INVOKEDYNAMIC: @@ -181,15 +236,16 @@ implements InstructionVisitor, } else { - // Check if the field is write-only or volatile, or if the - // invoked method is causing any side effects. + // Check if the invoked method is causing any side effects. clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this); } break; + case InstructionConstants.OP_ANEWARRAY: case InstructionConstants.OP_CHECKCAST: + case InstructionConstants.OP_MULTIANEWARRAY: // This instructions strictly taken may cause a side effect - // (ClassCastException). + // (ClassCastException, NegativeArraySizeException). hasSideEffects = OPTIMIZE_CONSERVATIVELY; break; } @@ -252,11 +308,9 @@ implements InstructionVisitor, { hasSideEffects = (includeLocalFieldAccess || !programClass.equals(referencingClass)) && - ((ReadWriteFieldMarker.isRead(programField) && - ReadWriteFieldMarker.isWritten(programField)) || - ((programField.getAccessFlags() & ClassConstants.INTERNAL_ACC_VOLATILE) != 0) || - (!programClass.equals(referencingClass) && - !initializedSuperClasses(referencingClass).containsAll(initializedSuperClasses(programClass)))); + ((writingField && ReadWriteFieldMarker.isRead(programField)) || + (programField.getAccessFlags() & ClassConstants.ACC_VOLATILE) != 0 || + mayHaveSideEffects(referencingClass, programClass)); } @@ -267,8 +321,7 @@ implements InstructionVisitor, hasSideEffects = !NoSideEffectMethodMarker.hasNoSideEffects(programMethod) && (SideEffectMethodMarker.hasSideEffects(programMethod) || - (!programClass.equals(referencingClass) && - !initializedSuperClasses(referencingClass).containsAll(initializedSuperClasses(programClass)))); + mayHaveSideEffects(referencingClass, programClass)); } @@ -285,6 +338,21 @@ implements InstructionVisitor, } + // Small utility methods. + + /** + * Returns whether a field reference or method invocation from the + * referencing class to the referenced class might have any side + * effects. + */ + private boolean mayHaveSideEffects(Clazz referencingClass, Clazz referencedClass) + { + return + !referencedClass.equals(referencingClass) && + !initializedSuperClasses(referencingClass).containsAll(initializedSuperClasses(referencedClass)); + } + + /** * Returns the set of superclasses and interfaces that are initialized. */ @@ -296,8 +364,8 @@ implements InstructionVisitor, // static initializers. clazz.hierarchyAccept(true, true, true, false, new StaticInitializerContainingClassFilter( - new NamedMethodVisitor(ClassConstants.INTERNAL_METHOD_NAME_CLINIT, - ClassConstants.INTERNAL_METHOD_TYPE_CLINIT, + new NamedMethodVisitor(ClassConstants.METHOD_NAME_CLINIT, + ClassConstants.METHOD_TYPE_CLINIT, new SideEffectMethodFilter( new MemberToClassVisitor( new ClassCollector(set)))))); 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