diff options
Diffstat (limited to 'src/proguard/optimize/peephole/BranchTargetFinder.java')
| -rw-r--r-- | src/proguard/optimize/peephole/BranchTargetFinder.java | 85 |
1 files changed, 49 insertions, 36 deletions
diff --git a/src/proguard/optimize/peephole/BranchTargetFinder.java b/src/proguard/optimize/peephole/BranchTargetFinder.java index 79499f1..507c1f8 100644 --- a/src/proguard/optimize/peephole/BranchTargetFinder.java +++ b/src/proguard/optimize/peephole/BranchTargetFinder.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 @@ -50,9 +50,14 @@ implements AttributeVisitor, private static boolean DEBUG = System.getProperty("btf") != null; //*/ - public static final int NONE = -2; - public static final int AT_METHOD_ENTRY = -1; + public static final int NONE = -1; + // We'll explicitly mark instructions that are not part of a subroutine, + // with NO_SUBROUTINE. Subroutines may just branch back into normal code + // (e.g. due to a break instruction in Java code), and we want to avoid + // marking such normal code as subroutine. The first mark wins, so we're + // assuming that such code is marked as normal code before it is marked + // as subroutine. public static final int UNKNOWN = -1; public static final int NO_SUBROUTINE = -2; @@ -355,24 +360,17 @@ implements AttributeVisitor, currentSubroutineStart = NO_SUBROUTINE; recentCreationOffsetIndex = 0; - // Initialize the stack of 'new' instruction offsets if this method - // is an instance initializer. - if (method.getName(clazz).equals(ClassConstants.INTERNAL_METHOD_NAME_INIT)) - { - recentCreationOffsets[recentCreationOffsetIndex++] = AT_METHOD_ENTRY; - } - // Mark branch targets by going over all instructions. codeAttribute.instructionsAccept(clazz, method, this); + + // Mark branch targets in the exception table. + codeAttribute.exceptionsAccept(clazz, method, this); } while (repeat); // The end of the code is a branch target sentinel. instructionMarks[codeLength] = BRANCH_TARGET; - // Mark branch targets in the exception table. - codeAttribute.exceptionsAccept(clazz, method, this); - if (containsSubroutines) { // Set the subroutine returning flag and the subroutine end at each @@ -487,33 +485,39 @@ implements AttributeVisitor, // Check if this is an instruction of a subroutine. checkSubroutine(offset); - // Check if the instruction is a 'new' instruction. - if (constantInstruction.opcode == InstructionConstants.OP_NEW) + byte opcode = constantInstruction.opcode; + if (opcode == InstructionConstants.OP_NEW) { // Push the 'new' instruction offset on the stack. recentCreationOffsets[recentCreationOffsetIndex++] = offset; } - else + else if (opcode == InstructionConstants.OP_INVOKESPECIAL) { - // Check if the instruction is an initializer invocation. + // Is it calling an instance initializer? isInitializer = false; clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this); if (isInitializer) { - // Pop the 'new' instruction offset from the stack. - int recentCreationOffset = recentCreationOffsets[--recentCreationOffsetIndex]; + // Do we have any 'new' instruction offsets on the stack? + if (recentCreationOffsetIndex > 0) + { + // Pop the 'new' instruction offset from the stack. + int recentCreationOffset = recentCreationOffsets[--recentCreationOffsetIndex]; - // Fill it out in the creation offsets. - creationOffsets[offset] = recentCreationOffset; + // Link the creation offset and the initialization offset. + // TODO: There could be multiple initialization offsets. + creationOffsets[offset] = recentCreationOffset; - // Fill out the initialization offsets. - if (recentCreationOffset == AT_METHOD_ENTRY) - { - superInitializationOffset = offset; + initializationOffsets[recentCreationOffset] = offset; } else { - initializationOffsets[recentCreationOffset] = offset; + // Remember the super initialization offset. + // TODO: There could be multiple initialization offsets. + // For instance, in the constructor of the generated class + // groovy.inspect.swingui.GeneratedBytecodeAwareGroovyClassLoader + // in groovy-all-2.2.1.jar. + superInitializationOffset = offset; } } } @@ -613,7 +617,8 @@ implements AttributeVisitor, public void visitMethodrefConstant(Clazz clazz, MethodrefConstant methodrefConstant) { - isInitializer = methodrefConstant.getName(clazz).equals(ClassConstants.INTERNAL_METHOD_NAME_INIT); + // Remember whether the method is an initializer. + isInitializer = methodrefConstant.getName(clazz).equals(ClassConstants.METHOD_NAME_INIT); } @@ -621,10 +626,24 @@ implements AttributeVisitor, public void visitExceptionInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, ExceptionInfo exceptionInfo) { + int startPC = exceptionInfo.u2startPC; + int endPC = exceptionInfo.u2endPC; + int handlerPC = exceptionInfo.u2handlerPC; + // Mark the exception offsets. - instructionMarks[exceptionInfo.u2startPC] |= EXCEPTION_START; - instructionMarks[exceptionInfo.u2endPC] |= EXCEPTION_END; - instructionMarks[exceptionInfo.u2handlerPC] |= EXCEPTION_HANDLER; + instructionMarks[startPC] |= EXCEPTION_START; + instructionMarks[endPC] |= EXCEPTION_END; + instructionMarks[handlerPC] |= EXCEPTION_HANDLER; + + // Mark the handler as part of a subroutine if necessary. + if (subroutineStarts[handlerPC] == UNKNOWN && + subroutineStarts[startPC] != UNKNOWN) + { + subroutineStarts[handlerPC] = subroutineStarts[startPC]; + + // We'll have to go over all instructions again. + repeat = true; + } } @@ -737,12 +756,6 @@ implements AttributeVisitor, { // Mark the subroutine start. subroutineStarts[offset] = currentSubroutineStart; - - if (currentSubroutineStart >= 0) - { - // Mark the subroutine end at the subroutine start. - subroutineEnds[currentSubroutineStart] = offset; - } } } } |