diff options
Diffstat (limited to 'src/proguard/optimize/evaluation/PartialEvaluator.java')
| -rw-r--r-- | src/proguard/optimize/evaluation/PartialEvaluator.java | 166 |
1 files changed, 86 insertions, 80 deletions
diff --git a/src/proguard/optimize/evaluation/PartialEvaluator.java b/src/proguard/optimize/evaluation/PartialEvaluator.java index 5790a36..6a5bedf 100644 --- a/src/proguard/optimize/evaluation/PartialEvaluator.java +++ b/src/proguard/optimize/evaluation/PartialEvaluator.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) 2002-2013 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 @@ -31,6 +31,8 @@ import proguard.evaluation.*; import proguard.evaluation.value.*; import proguard.optimize.peephole.BranchTargetFinder; +import java.util.Arrays; + /** * This AttributeVisitor performs partial evaluation on the code attributes * that it visits. @@ -68,7 +70,6 @@ implements AttributeVisitor, private TracedStack[] stacksAfter = new TracedStack[ClassConstants.TYPICAL_CODE_LENGTH]; private boolean[] generalizedContexts = new boolean[ClassConstants.TYPICAL_CODE_LENGTH]; private int[] evaluationCounts = new int[ClassConstants.TYPICAL_CODE_LENGTH]; - private int[] initializedVariables = new int[ClassConstants.TYPICAL_CODE_LENGTH]; private boolean evaluateExceptions; private final BasicBranchUnit branchUnit; @@ -189,6 +190,47 @@ implements AttributeVisitor, if (DEBUG) { method.accept(clazz, new ClassPrinter()); + + System.out.println("Evaluation results:"); + + int offset = 0; + do + { + if (isBranchOrExceptionTarget(offset)) + { + System.out.println("Branch target from ["+branchOriginValues[offset]+"]:"); + if (isTraced(offset)) + { + System.out.println(" Vars: "+variablesBefore[offset]); + System.out.println(" Stack: "+stacksBefore[offset]); + } + } + + Instruction instruction = InstructionFactory.create(codeAttribute.code, + offset); + System.out.println(instruction.toString(offset)); + + if (isTraced(offset)) + { + int initializationOffset = branchTargetFinder.initializationOffset(offset); + if (initializationOffset != NONE) + { + System.out.println(" is to be initialized at ["+initializationOffset+"]"); + } + + InstructionOffsetValue branchTargets = branchTargets(offset); + if (branchTargets != null) + { + System.out.println(" has overall been branching to "+branchTargets); + } + + System.out.println(" Vars: "+variablesAfter[offset]); + System.out.println(" Stack: "+stacksAfter[offset]); + } + + offset += instruction.length(offset); + } + while (offset < codeAttribute.u4codeLength); } throw ex; @@ -212,7 +254,8 @@ implements AttributeVisitor, TracedStack stack = new TracedStack(codeAttribute.u2maxStack); // Initialize the reusable arrays and variables. - initializeVariables(clazz, method, codeAttribute, variables, stack); + initializeArrays(codeAttribute); + initializeParameters(clazz, method, codeAttribute, variables); // Find all instruction offsets,... codeAttribute.accept(clazz, method, branchTargetFinder); @@ -249,12 +292,6 @@ implements AttributeVisitor, if (isTraced(offset)) { - int variableIndex = initializedVariable(offset); - if (variableIndex >= 0) - { - System.out.println(" is initializing variable v"+variableIndex); - } - int initializationOffset = branchTargetFinder.initializationOffset(offset); if (initializationOffset != NONE) { @@ -479,16 +516,6 @@ implements AttributeVisitor, } - /** - * Returns the variable that is initialized at the given instruction offset, - * or <code>NONE</code> if no variable was initialized. - */ - public int initializedVariable(int instructionOffset) - { - return initializedVariables[instructionOffset]; - } - - // Utility methods to evaluate instruction blocks. /** @@ -702,9 +729,6 @@ implements AttributeVisitor, // Reset the trace value. InstructionOffsetValue traceValue = InstructionOffsetValue.EMPTY_VALUE; - // Reset the initialization flag. - variables.resetInitialization(); - // Note that the instruction is only volatile. Instruction instruction = InstructionFactory.create(code, instructionOffset); @@ -743,9 +767,6 @@ implements AttributeVisitor, throw ex; } - // Collect the offsets of the instructions whose results were used. - initializedVariables[instructionOffset] = variables.getInitializationIndex(); - // Collect the branch targets from the branch unit. InstructionOffsetValue branchTargets = branchUnit.getTraceBranchTargets(); int branchTargetCount = branchTargets.instructionOffsetCount(); @@ -844,8 +865,7 @@ implements AttributeVisitor, if (instruction.opcode == InstructionConstants.OP_JSR || instruction.opcode == InstructionConstants.OP_JSR_W) { - // Evaluate the subroutine, possibly in another partial - // evaluator. + // Evaluate the subroutine in another partial evaluator. evaluateSubroutine(clazz, method, codeAttribute, @@ -887,21 +907,13 @@ implements AttributeVisitor, if (DEBUG) System.out.println("Evaluating subroutine from "+subroutineStart+" to "+subroutineEnd); - PartialEvaluator subroutinePartialEvaluator = this; - - // Create a temporary partial evaluator if necessary. - if (evaluationCounts[subroutineStart] > 0) - { - if (DEBUG) System.out.println("Creating new partial evaluator for subroutine"); - - subroutinePartialEvaluator = new PartialEvaluator(this); + // Create a temporary partial evaluator, so there are no conflicts + // with variables that are alive across subroutine invocations, between + // different invocations. + PartialEvaluator subroutinePartialEvaluator = + new PartialEvaluator(this); - subroutinePartialEvaluator.initializeVariables(clazz, - method, - codeAttribute, - variables, - stack); - } + subroutinePartialEvaluator.initializeArrays(codeAttribute); // Evaluate the subroutine. subroutinePartialEvaluator.evaluateInstructionBlockAndExceptionHandlers(clazz, @@ -912,11 +924,9 @@ implements AttributeVisitor, subroutineStart, subroutineEnd); - // Merge back the temporary partial evaluator if necessary. - if (subroutinePartialEvaluator != this) - { - generalize(subroutinePartialEvaluator, 0, codeAttribute.u4codeLength); - } + // Merge back the temporary partial evaluator. This way, we'll get + // the lowest common denominator of stacks and variables. + generalize(subroutinePartialEvaluator, 0, codeAttribute.u4codeLength); if (DEBUG) System.out.println("Ending subroutine from "+subroutineStart+" to "+subroutineEnd); } @@ -952,13 +962,12 @@ implements AttributeVisitor, if (evaluationCounts[offset] == 0) { - variablesBefore[offset] = other.variablesBefore[offset]; - stacksBefore[offset] = other.stacksBefore[offset]; - variablesAfter[offset] = other.variablesAfter[offset]; - stacksAfter[offset] = other.stacksAfter[offset]; - generalizedContexts[offset] = other.generalizedContexts[offset]; - evaluationCounts[offset] = other.evaluationCounts[offset]; - initializedVariables[offset] = other.initializedVariables[offset]; + variablesBefore[offset] = other.variablesBefore[offset]; + stacksBefore[offset] = other.stacksBefore[offset]; + variablesAfter[offset] = other.variablesAfter[offset]; + stacksAfter[offset] = other.stacksAfter[offset]; + generalizedContexts[offset] = other.generalizedContexts[offset]; + evaluationCounts[offset] = other.evaluationCounts[offset]; } else { @@ -968,7 +977,6 @@ implements AttributeVisitor, stacksAfter[offset] .generalize(other.stacksAfter[offset]); //generalizedContexts[offset] evaluationCounts[offset] += other.evaluationCounts[offset]; - //initializedVariables[offset] } } } @@ -1094,11 +1102,7 @@ implements AttributeVisitor, /** * Initializes the data structures for the variables, stack, etc. */ - private void initializeVariables(Clazz clazz, - Method method, - CodeAttribute codeAttribute, - TracedVariables variables, - TracedStack stack) + private void initializeArrays(CodeAttribute codeAttribute) { int codeLength = codeAttribute.u4codeLength; @@ -1106,33 +1110,25 @@ implements AttributeVisitor, if (variablesAfter.length < codeLength) { // Create new arrays. - branchOriginValues = new InstructionOffsetValue[codeLength]; - branchTargetValues = new InstructionOffsetValue[codeLength]; - variablesBefore = new TracedVariables[codeLength]; - stacksBefore = new TracedStack[codeLength]; - variablesAfter = new TracedVariables[codeLength]; - stacksAfter = new TracedStack[codeLength]; - generalizedContexts = new boolean[codeLength]; - evaluationCounts = new int[codeLength]; - initializedVariables = new int[codeLength]; - - // Reset the arrays. - for (int index = 0; index < codeLength; index++) - { - initializedVariables[index] = NONE; - } + branchOriginValues = new InstructionOffsetValue[codeLength]; + branchTargetValues = new InstructionOffsetValue[codeLength]; + variablesBefore = new TracedVariables[codeLength]; + stacksBefore = new TracedStack[codeLength]; + variablesAfter = new TracedVariables[codeLength]; + stacksAfter = new TracedStack[codeLength]; + generalizedContexts = new boolean[codeLength]; + evaluationCounts = new int[codeLength]; } else { // Reset the arrays. + Arrays.fill(branchOriginValues, null); + Arrays.fill(branchTargetValues, null); + Arrays.fill(generalizedContexts, false); + Arrays.fill(evaluationCounts, 0); + for (int index = 0; index < codeLength; index++) { - branchOriginValues[index] = null; - branchTargetValues[index] = null; - generalizedContexts[index] = false; - evaluationCounts[index] = 0; - initializedVariables[index] = NONE; - if (variablesBefore[index] != null) { variablesBefore[index].reset(codeAttribute.u2maxLocals); @@ -1154,7 +1150,17 @@ implements AttributeVisitor, } } } + } + + /** + * Initializes the data structures for the variables, stack, etc. + */ + private void initializeParameters(Clazz clazz, + Method method, + CodeAttribute codeAttribute, + TracedVariables variables) + { // Create the method parameters. TracedVariables parameters = new TracedVariables(codeAttribute.u2maxLocals); |