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Diffstat (limited to 'src/proguard/optimize/info/SideEffectInstructionChecker.java')
| -rw-r--r-- | src/proguard/optimize/info/SideEffectInstructionChecker.java | 375 |
1 files changed, 0 insertions, 375 deletions
diff --git a/src/proguard/optimize/info/SideEffectInstructionChecker.java b/src/proguard/optimize/info/SideEffectInstructionChecker.java deleted file mode 100644 index 49a1281..0000000 --- a/src/proguard/optimize/info/SideEffectInstructionChecker.java +++ /dev/null @@ -1,375 +0,0 @@ -/* - * ProGuard -- shrinking, optimization, obfuscation, and preverification - * of Java bytecode. - * - * 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 - * Software Foundation; either version 2 of the License, or (at your option) - * any later version. - * - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along - * with this program; if not, write to the Free Software Foundation, Inc., - * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ -package proguard.optimize.info; - -import proguard.classfile.*; -import proguard.classfile.attribute.CodeAttribute; -import proguard.classfile.constant.*; -import proguard.classfile.constant.visitor.ConstantVisitor; -import proguard.classfile.instruction.*; -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 outside of - * its method. Return instructions and local field accesses can be included or - * not. - * - * @see ReadWriteFieldMarker - * @see StaticInitializerContainingClassMarker - * @see NoSideEffectMethodMarker - * @see SideEffectMethodMarker - * @author Eric Lafortune - */ -public class SideEffectInstructionChecker -extends SimplifiedVisitor -implements InstructionVisitor, - ConstantVisitor, - MemberVisitor -{ - 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) - { - this.includeReturnInstructions = includeReturnInstructions; - this.includeLocalFieldAccess = includeLocalFieldAccess; - } - - - /** - * Returns whether the given instruction has side effects outside of its - * method. - */ - public boolean hasSideEffects(Clazz clazz, - Method method, - CodeAttribute codeAttribute, - int offset, - Instruction instruction) - { - hasSideEffects = false; - - instruction.accept(clazz, method, codeAttribute, offset, this); - - return hasSideEffects; - } - - - // Implementations for InstructionVisitor. - - public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {} - - - public void visitSimpleInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, SimpleInstruction simpleInstruction) - { - byte opcode = simpleInstruction.opcode; - - // 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: - case InstructionConstants.OP_DALOAD: - case InstructionConstants.OP_AALOAD: - 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 - // (ArithmeticException, NullPointerException, - // ArrayIndexOutOfBoundsException, NegativeArraySizeException). - hasSideEffects = OPTIMIZE_CONSERVATIVELY; - break; - - case InstructionConstants.OP_IASTORE: - case InstructionConstants.OP_LASTORE: - case InstructionConstants.OP_FASTORE: - case InstructionConstants.OP_DASTORE: - case InstructionConstants.OP_AASTORE: - case InstructionConstants.OP_BASTORE: - case InstructionConstants.OP_CASTORE: - case InstructionConstants.OP_SASTORE: - case InstructionConstants.OP_ATHROW : - case InstructionConstants.OP_MONITORENTER: - case InstructionConstants.OP_MONITOREXIT: - // These instructions always cause a side effect. - hasSideEffects = true; - break; - - case InstructionConstants.OP_IRETURN: - case InstructionConstants.OP_LRETURN: - case InstructionConstants.OP_FRETURN: - case InstructionConstants.OP_DRETURN: - case InstructionConstants.OP_ARETURN: - case InstructionConstants.OP_RETURN: - // These instructions may have a side effect. - hasSideEffects = includeReturnInstructions; - break; - } - } - - - public void visitVariableInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, VariableInstruction variableInstruction) - { - byte opcode = variableInstruction.opcode; - - // Check for instructions that might cause side effects. - switch (opcode) - { - case InstructionConstants.OP_RET: - // This instruction may have a side effect. - hasSideEffects = includeReturnInstructions; - break; - } - } - - - 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. - 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: - // 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: - if (OPTIMIZE_CONSERVATIVELY) - { - // These instructions strictly taken may cause a side effect - // (NullPointerException). - hasSideEffects = true; - } - else - { - // 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, NegativeArraySizeException). - hasSideEffects = OPTIMIZE_CONSERVATIVELY; - break; - } - } - - - public void visitBranchInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, BranchInstruction branchInstruction) - { - byte opcode = branchInstruction.opcode; - - // Check for instructions that might cause side effects. - switch (opcode) - { - case InstructionConstants.OP_JSR: - case InstructionConstants.OP_JSR_W: - hasSideEffects = includeReturnInstructions; - break; - } - } - - - // 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, if known. - fieldrefConstant.referencedMemberAccept(this); - } - - - public void visitAnyMethodrefConstant(Clazz clazz, RefConstant refConstant) - { - // Pass the referencing class. - referencingClass = clazz; - - // We'll have to assume invoking an unknown method has side effects. - hasSideEffects = true; - - // Check the referenced method, if known. - refConstant.referencedMemberAccept(this); - } - - - // Implementations for MemberVisitor. - - public void visitProgramField(ProgramClass programClass, ProgramField programField) - { - hasSideEffects = - (includeLocalFieldAccess || !programClass.equals(referencingClass)) && - ((writingField && ReadWriteFieldMarker.isRead(programField)) || - (programField.getAccessFlags() & ClassConstants.ACC_VOLATILE) != 0 || - mayHaveSideEffects(referencingClass, programClass)); - } - - - public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) - { - // Note that side effects already include synchronization of some - // implementation of the method. - hasSideEffects = - !NoSideEffectMethodMarker.hasNoSideEffects(programMethod) && - (SideEffectMethodMarker.hasSideEffects(programMethod) || - mayHaveSideEffects(referencingClass, programClass)); - } - - - public void visitLibraryField(LibraryClass libraryClass, LibraryField libraryField) - { - hasSideEffects = true; - } - - - public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod) - { - hasSideEffects = - !NoSideEffectMethodMarker.hasNoSideEffects(libraryMethod); - } - - - // 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. - */ - 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 NamedMethodVisitor(ClassConstants.METHOD_NAME_CLINIT, - ClassConstants.METHOD_TYPE_CLINIT, - new SideEffectMethodFilter( - new MemberToClassVisitor( - new ClassCollector(set)))))); - - return set; - } -} |