Examples with BytecodeLocalVariableTableEntry de.mirkosertic.bytecoder.core.BytecodeLocalVariableTableEntry used on opensource projects

Example 1 with BytecodeLocalVariableTableEntry

use of de.mirkosertic.bytecoder.core.BytecodeLocalVariableTableEntry in project Bytecoder by mirkosertic.

the class NaiveProgramGenerator method generateFrom.

@Override
public Program generateFrom(BytecodeClass aOwningClass, BytecodeMethod aMethod) {
    BytecodeCodeAttributeInfo theCode = aMethod.getCode(aOwningClass);
    Program theProgram = new Program();
    // Initialize programm arguments
    BytecodeLocalVariableTableAttributeInfo theDebugInfos = null;
    if (theCode != null) {
        theDebugInfos = theCode.attributeByType(BytecodeLocalVariableTableAttributeInfo.class);
    }
    int theCurrentIndex = 0;
    if (!aMethod.getAccessFlags().isStatic()) {
        theProgram.addArgument(new LocalVariableDescription(theCurrentIndex), Variable.createThisRef());
        theCurrentIndex++;
    }
    BytecodeTypeRef[] theTypes = aMethod.getSignature().getArguments();
    for (int i = 0; i < theTypes.length; i++) {
        BytecodeTypeRef theRef = theTypes[i];
        if (theDebugInfos != null) {
            BytecodeLocalVariableTableEntry theEntry = theDebugInfos.matchingEntryFor(BytecodeOpcodeAddress.START_AT_ZERO, theCurrentIndex);
            if (theEntry != null) {
                String theVariableName = theDebugInfos.resolveVariableName(theEntry);
                theProgram.addArgument(new LocalVariableDescription(theCurrentIndex), Variable.createMethodParameter(i + 1, theVariableName, TypeRef.toType(theTypes[i])));
            } else {
                theProgram.addArgument(new LocalVariableDescription(theCurrentIndex), Variable.createMethodParameter(i + 1, TypeRef.toType(theTypes[i])));
            }
        } else {
            theProgram.addArgument(new LocalVariableDescription(theCurrentIndex), Variable.createMethodParameter(i + 1, TypeRef.toType(theTypes[i])));
        }
        theCurrentIndex++;
        if (theRef == BytecodePrimitiveTypeRef.LONG || theRef == BytecodePrimitiveTypeRef.DOUBLE) {
            theCurrentIndex++;
        }
    }
    List<BytecodeBasicBlock> theBlocks = new ArrayList<>();
    Function<BytecodeOpcodeAddress, BytecodeBasicBlock> theBasicBlockByAddress = aValue -> {
        for (BytecodeBasicBlock theBlock : theBlocks) {
            if (Objects.equals(aValue, theBlock.getStartAddress())) {
                return theBlock;
            }
        }
        throw new IllegalStateException("No Block for " + aValue.getAddress());
    };
    if (aMethod.getAccessFlags().isAbstract() || aMethod.getAccessFlags().isNative()) {
        return theProgram;
    }
    BytecodeProgram theBytecode = theCode.getProgramm();
    Set<BytecodeOpcodeAddress> theJumpTarget = theBytecode.getJumpTargets();
    BytecodeBasicBlock currentBlock = null;
    for (BytecodeInstruction theInstruction : theBytecode.getInstructions()) {
        if (theJumpTarget.contains(theInstruction.getOpcodeAddress())) {
            // Jump target, start a new basic block
            currentBlock = null;
        }
        if (theBytecode.isStartOfTryBlock(theInstruction.getOpcodeAddress())) {
            // start of try block, hence new basic block
            currentBlock = null;
        }
        if (currentBlock == null) {
            BytecodeBasicBlock.Type theType = BytecodeBasicBlock.Type.NORMAL;
            for (BytecodeExceptionTableEntry theHandler : theBytecode.getExceptionHandlers()) {
                if (Objects.equals(theHandler.getHandlerPc(), theInstruction.getOpcodeAddress())) {
                    if (theHandler.isFinally()) {
                        theType = BytecodeBasicBlock.Type.FINALLY;
                    } else {
                        theType = BytecodeBasicBlock.Type.EXCEPTION_HANDLER;
                    }
                }
            }
            BytecodeBasicBlock theCurrentTemp = currentBlock;
            currentBlock = new BytecodeBasicBlock(theType);
            if (theCurrentTemp != null && !theCurrentTemp.endsWithReturn() && !theCurrentTemp.endsWithThrow() && theCurrentTemp.endsWithGoto() && !theCurrentTemp.endsWithConditionalJump()) {
                theCurrentTemp.addSuccessor(currentBlock);
            }
            theBlocks.add(currentBlock);
        }
        currentBlock.addInstruction(theInstruction);
        if (theInstruction.isJumpSource()) {
            // conditional or unconditional jump, start new basic block
            currentBlock = null;
        } else if (theInstruction instanceof BytecodeInstructionRET) {
            // returning, start new basic block
            currentBlock = null;
        } else if (theInstruction instanceof BytecodeInstructionRETURN) {
            // returning, start new basic block
            currentBlock = null;
        } else if (theInstruction instanceof BytecodeInstructionObjectRETURN) {
            // returning, start new basic block
            currentBlock = null;
        } else if (theInstruction instanceof BytecodeInstructionGenericRETURN) {
            // returning, start new basic block
            currentBlock = null;
        } else if (theInstruction instanceof BytecodeInstructionATHROW) {
            // thowing an exception, start new basic block
            currentBlock = null;
        } else if (theInstruction instanceof BytecodeInstructionInvoke) {
        // invocation, start new basic block
        // currentBlock = null;
        }
    }
    // Now, we have to build the successors of each block
    for (int i = 0; i < theBlocks.size(); i++) {
        BytecodeBasicBlock theBlock = theBlocks.get(i);
        if (!theBlock.endsWithReturn() && !theBlock.endsWithThrow()) {
            if (theBlock.endsWithJump()) {
                for (BytecodeInstruction theInstruction : theBlock.getInstructions()) {
                    if (theInstruction.isJumpSource()) {
                        for (BytecodeOpcodeAddress theBlockJumpTarget : theInstruction.getPotentialJumpTargets()) {
                            theBlock.addSuccessor(theBasicBlockByAddress.apply(theBlockJumpTarget));
                        }
                    }
                }
                if (theBlock.endsWithConditionalJump()) {
                    if (i < theBlocks.size() - 1) {
                        theBlock.addSuccessor(theBlocks.get(i + 1));
                    } else {
                        throw new IllegalStateException("Block at end with no jump target!");
                    }
                }
            } else {
                if (i < theBlocks.size() - 1) {
                    theBlock.addSuccessor(theBlocks.get(i + 1));
                } else {
                    throw new IllegalStateException("Block at end with no jump target!");
                }
            }
        }
    }
    // Ok, now we transform it to GraphNodes with yet empty content
    Map<BytecodeBasicBlock, RegionNode> theCreatedBlocks = new HashMap<>();
    ControlFlowGraph theGraph = theProgram.getControlFlowGraph();
    for (BytecodeBasicBlock theBlock : theBlocks) {
        RegionNode theSingleAssignmentBlock;
        switch(theBlock.getType()) {
            case NORMAL:
                theSingleAssignmentBlock = theGraph.createAt(theBlock.getStartAddress(), RegionNode.BlockType.NORMAL);
                break;
            case EXCEPTION_HANDLER:
                theSingleAssignmentBlock = theGraph.createAt(theBlock.getStartAddress(), RegionNode.BlockType.EXCEPTION_HANDLER);
                break;
            case FINALLY:
                theSingleAssignmentBlock = theGraph.createAt(theBlock.getStartAddress(), RegionNode.BlockType.FINALLY);
                break;
            default:
                throw new IllegalStateException("Unsupported block type : " + theBlock.getType());
        }
        theCreatedBlocks.put(theBlock, theSingleAssignmentBlock);
    }
    // Initialize Block dependency graph
    for (Map.Entry<BytecodeBasicBlock, RegionNode> theEntry : theCreatedBlocks.entrySet()) {
        for (BytecodeBasicBlock theSuccessor : theEntry.getKey().getSuccessors()) {
            RegionNode theSuccessorBlock = theCreatedBlocks.get(theSuccessor);
            if (theSuccessorBlock == null) {
                throw new IllegalStateException("Cannot find successor block");
            }
            theEntry.getValue().addSuccessor(theSuccessorBlock);
        }
    }
    // And add dependencies for exception handlers and finally blocks
    for (BytecodeExceptionTableEntry theHandler : theBytecode.getExceptionHandlers()) {
        RegionNode theStart = theProgram.getControlFlowGraph().nodeStartingAt(theHandler.getStartPC());
        RegionNode theHandlerNode = theProgram.getControlFlowGraph().nodeStartingAt(theHandler.getHandlerPc());
        theStart.addSuccessor(theHandlerNode);
    }
    // Now we can add the SSA instructions to the graph nodes
    Set<RegionNode> theVisited = new HashSet<>();
    RegionNode theStart = theProgram.getControlFlowGraph().startNode();
    // First of all, we need to mark the back-edges of the graph
    theProgram.getControlFlowGraph().calculateReachabilityAndMarkBackEdges();
    try {
        // Now we can continue to create the program flow
        ParsingHelperCache theParsingHelperCache = new ParsingHelperCache(theProgram, aMethod, theStart, theDebugInfos);
        // This will traverse the CFG from bottom to top
        for (RegionNode theNode : theProgram.getControlFlowGraph().finalNodes()) {
            initializeBlock(theProgram, aOwningClass, aMethod, theNode, theVisited, theParsingHelperCache, theBasicBlockByAddress);
        }
        // finally blocks
        for (Map.Entry<BytecodeBasicBlock, RegionNode> theEntry : theCreatedBlocks.entrySet()) {
            RegionNode theBlock = theEntry.getValue();
            if (theBlock.getType() != RegionNode.BlockType.NORMAL) {
                initializeBlock(theProgram, aOwningClass, aMethod, theBlock, theVisited, theParsingHelperCache, theBasicBlockByAddress);
            }
        }
        // Additionally, we have to add gotos
        for (RegionNode theNode : theProgram.getControlFlowGraph().getKnownNodes()) {
            ExpressionList theCurrentList = theNode.getExpressions();
            Expression theLast = theCurrentList.lastExpression();
            if (theLast instanceof GotoExpression) {
                GotoExpression theGoto = (GotoExpression) theLast;
                if (Objects.equals(theGoto.getJumpTarget(), theNode.getStartAddress())) {
                    theCurrentList.remove(theGoto);
                }
            }
            if (!theNode.getExpressions().endWithNeverReturningExpression()) {
                Map<RegionNode.Edge, RegionNode> theSuccessors = theNode.getSuccessors();
                for (Expression theExpression : theCurrentList.toList()) {
                    if (theExpression instanceof IFExpression) {
                        IFExpression theIF = (IFExpression) theExpression;
                        BytecodeOpcodeAddress theGoto = theIF.getGotoAddress();
                        theSuccessors = theSuccessors.entrySet().stream().filter(t -> !Objects.equals(t.getValue().getStartAddress(), theGoto)).collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
                    }
                }
                List<RegionNode> theSuccessorRegions = theSuccessors.values().stream().filter(t -> t.getType() == RegionNode.BlockType.NORMAL).collect(Collectors.toList());
                if (theSuccessorRegions.size() == 1) {
                    theNode.getExpressions().add(new GotoExpression(theSuccessorRegions.get(0).getStartAddress()).withComment("Resolving pass thru direct"));
                } else {
                    // Special case, the node includes gotos and a fall thru to the same node
                    theSuccessors = theNode.getSuccessors();
                    theSuccessorRegions = theSuccessors.values().stream().filter(t -> t.getType() == RegionNode.BlockType.NORMAL).collect(Collectors.toList());
                    if (theSuccessorRegions.size() == 1) {
                        theNode.getExpressions().add(new GotoExpression(theSuccessorRegions.get(0).getStartAddress()).withComment("Resolving pass thru direct"));
                    } else {
                        throw new IllegalStateException("Invalid number of successors : " + theSuccessors.size() + " for " + theNode.getStartAddress().getAddress());
                    }
                }
            }
        }
        // Check that all PHI-propagations for back-edges are set
        for (RegionNode theNode : theProgram.getControlFlowGraph().getKnownNodes()) {
            ParsingHelper theHelper = theParsingHelperCache.resolveFinalStateForNode(theNode);
            for (Map.Entry<RegionNode.Edge, RegionNode> theEdge : theNode.getSuccessors().entrySet()) {
                if (theEdge.getKey().getType() == RegionNode.EdgeType.BACK) {
                    RegionNode theReceiving = theEdge.getValue();
                    BlockState theReceivingState = theReceiving.toStartState();
                    for (Map.Entry<VariableDescription, Value> theEntry : theReceivingState.getPorts().entrySet()) {
                        Value theExportingValue = theHelper.requestValue(theEntry.getKey());
                        if (theExportingValue == null) {
                            throw new IllegalStateException("No value for " + theEntry.getKey() + " to jump from " + theNode.getStartAddress().getAddress() + " to " + theReceiving.getStartAddress().getAddress());
                        }
                        Variable theReceivingTarget = (Variable) theEntry.getValue();
                        theReceivingTarget.initializeWith(theExportingValue);
                    }
                }
            }
        }
        // Make sure that all jump conditions are met
        for (RegionNode theNode : theProgram.getControlFlowGraph().getKnownNodes()) {
            forEachExpressionOf(theNode, aPoint -> {
                if (aPoint.expression instanceof GotoExpression) {
                    GotoExpression theGoto = (GotoExpression) aPoint.expression;
                    RegionNode theGotoNode = theProgram.getControlFlowGraph().nodeStartingAt(theGoto.getJumpTarget());
                    BlockState theImportingState = theGotoNode.toStartState();
                    for (Map.Entry<VariableDescription, Value> theImporting : theImportingState.getPorts().entrySet()) {
                        ParsingHelper theHelper = theParsingHelperCache.resolveFinalStateForNode(theNode);
                        Value theExportingValue = theHelper.requestValue(theImporting.getKey());
                        if (theExportingValue == null) {
                            throw new IllegalStateException("No value for " + theImporting.getKey() + " to jump from " + theNode.getStartAddress().getAddress() + " to " + theGotoNode.getStartAddress().getAddress());
                        }
                    }
                }
            });
        }
        // Insert PHI value resolving at required places
        for (RegionNode theNode : theProgram.getControlFlowGraph().getKnownNodes()) {
            forEachExpressionOf(theNode, aPoint -> {
                if (aPoint.expression instanceof GotoExpression) {
                    GotoExpression theGoto = (GotoExpression) aPoint.expression;
                    RegionNode theGotoNode = theProgram.getControlFlowGraph().nodeStartingAt(theGoto.getJumpTarget());
                    BlockState theImportingState = theGotoNode.toStartState();
                    String theComments = "";
                    for (Map.Entry<VariableDescription, Value> theImporting : theImportingState.getPorts().entrySet()) {
                        theComments = theComments + theImporting.getKey() + " is of type " + theImporting.getValue().resolveType().resolve() + " with values " + theImporting.getValue().incomingDataFlows();
                        Value theReceivingValue = theImporting.getValue();
                        ParsingHelper theHelper = theParsingHelperCache.resolveFinalStateForNode(theNode);
                        Value theExportingValue = theHelper.requestValue(theImporting.getKey());
                        if (theExportingValue == null) {
                            throw new IllegalStateException("No value for " + theImporting.getKey() + " to jump from " + theNode.getStartAddress().getAddress() + " to " + theGotoNode.getStartAddress().getAddress());
                        }
                        if (theReceivingValue != theExportingValue) {
                            VariableAssignmentExpression theInit = new VariableAssignmentExpression((Variable) theReceivingValue, theExportingValue);
                            aPoint.expressionList.addBefore(theInit, theGoto);
                        }
                    }
                    theGoto.withComment(theComments);
                }
            });
        }
    } catch (Exception e) {
        throw new ControlFlowProcessingException("Error processing CFG for " + aOwningClass.getThisInfo().getConstant().stringValue() + "." + aMethod.getName().stringValue(), e, theProgram.getControlFlowGraph());
    }
    return theProgram;
}