Examples with SpecialBlockImpl org.checkerframework.dataflow.cfg.block.SpecialBlockImpl used on opensource projects

Example 1 with SpecialBlockImpl

use of org.checkerframework.dataflow.cfg.block.SpecialBlockImpl in project checker-framework by typetools.

the class CFGTranslationPhaseTwo method process.

/**
 * Perform phase two of the translation.
 *
 * @param in the result of phase one
 * @return a control flow graph that might still contain degenerate basic block (such as empty
 *     regular basic blocks or conditional blocks with the same block as 'then' and 'else'
 *     successor)
 */
// AST node comparisons
@SuppressWarnings("interning:not.interned")
public static ControlFlowGraph process(PhaseOneResult in) {
    Map<Label, Integer> bindings = in.bindings;
    ArrayList<ExtendedNode> nodeList = in.nodeList;
    // A leader is an extended node which will give rise to a basic block in phase two.
    Set<Integer> leaders = in.leaders;
    assert !in.nodeList.isEmpty();
    // exit blocks
    SpecialBlockImpl regularExitBlock = new SpecialBlockImpl(SpecialBlockType.EXIT);
    SpecialBlockImpl exceptionalExitBlock = new SpecialBlockImpl(SpecialBlockType.EXCEPTIONAL_EXIT);
    // record missing edges that will be added later
    Set<MissingEdge> missingEdges = new MostlySingleton<>();
    // missing exceptional edges
    Set<MissingEdge> missingExceptionalEdges = new LinkedHashSet<>();
    // create start block
    SpecialBlockImpl startBlock = new SpecialBlockImpl(SpecialBlockType.ENTRY);
    missingEdges.add(new MissingEdge(startBlock, 0));
    // Loop through all 'leaders' (while dynamically detecting the leaders).
    // block being processed/built
    @NonNull RegularBlockImpl block = new RegularBlockImpl();
    int i = 0;
    for (ExtendedNode node : nodeList) {
        switch(node.getType()) {
            case NODE:
                if (leaders.contains(i)) {
                    RegularBlockImpl b = new RegularBlockImpl();
                    block.setSuccessor(b);
                    block = b;
                }
                block.addNode(node.getNode());
                node.setBlock(block);
                // does this node end the execution (modeled as an edge to
                // the exceptional exit block)
                boolean terminatesExecution = node.getTerminatesExecution();
                if (terminatesExecution) {
                    block.setSuccessor(exceptionalExitBlock);
                    block = new RegularBlockImpl();
                }
                break;
            case CONDITIONAL_JUMP:
                {
                    ConditionalJump cj = (ConditionalJump) node;
                    // Exception nodes may fall through to conditional jumps, so we set the block which is
                    // required for the insertion of missing edges.
                    node.setBlock(block);
                    assert block != null;
                    final ConditionalBlockImpl cb = new ConditionalBlockImpl();
                    if (cj.getTrueFlowRule() != null) {
                        cb.setThenFlowRule(cj.getTrueFlowRule());
                    }
                    if (cj.getFalseFlowRule() != null) {
                        cb.setElseFlowRule(cj.getFalseFlowRule());
                    }
                    block.setSuccessor(cb);
                    block = new RegularBlockImpl();
                    // use two anonymous SingleSuccessorBlockImpl that set the
                    // 'then' and 'else' successor of the conditional block
                    final Label thenLabel = cj.getThenLabel();
                    final Label elseLabel = cj.getElseLabel();
                    Integer target = bindings.get(thenLabel);
                    assert target != null;
                    missingEdges.add(new MissingEdge(new RegularBlockImpl() {

                        @Override
                        public void setSuccessor(BlockImpl successor) {
                            cb.setThenSuccessor(successor);
                        }
                    }, target));
                    target = bindings.get(elseLabel);
                    assert target != null;
                    missingEdges.add(new MissingEdge(new RegularBlockImpl() {

                        @Override
                        public void setSuccessor(BlockImpl successor) {
                            cb.setElseSuccessor(successor);
                        }
                    }, target));
                    break;
                }
            case UNCONDITIONAL_JUMP:
                UnconditionalJump uj = (UnconditionalJump) node;
                if (leaders.contains(i)) {
                    RegularBlockImpl b = new RegularBlockImpl();
                    block.setSuccessor(b);
                    block = b;
                }
                node.setBlock(block);
                if (node.getLabel() == in.regularExitLabel) {
                    block.setSuccessor(regularExitBlock);
                    block.setFlowRule(uj.getFlowRule());
                } else if (node.getLabel() == in.exceptionalExitLabel) {
                    block.setSuccessor(exceptionalExitBlock);
                    block.setFlowRule(uj.getFlowRule());
                } else {
                    int target = bindings.get(node.getLabel());
                    missingEdges.add(new MissingEdge(block, target, uj.getFlowRule()));
                }
                block = new RegularBlockImpl();
                break;
            case EXCEPTION_NODE:
                NodeWithExceptionsHolder en = (NodeWithExceptionsHolder) node;
                // create new exception block and link with previous block
                ExceptionBlockImpl e = new ExceptionBlockImpl();
                Node nn = en.getNode();
                e.setNode(nn);
                node.setBlock(e);
                block.setSuccessor(e);
                block = new RegularBlockImpl();
                // sure).
                if (!node.getTerminatesExecution()) {
                    missingEdges.add(new MissingEdge(e, i + 1));
                }
                // exceptional edges
                for (Map.Entry<TypeMirror, Set<Label>> entry : en.getExceptions().entrySet()) {
                    TypeMirror cause = entry.getKey();
                    for (Label label : entry.getValue()) {
                        Integer target = bindings.get(label);
                        // TODO: This is sometimes null; is this a problem?
                        // assert target != null;
                        missingExceptionalEdges.add(new MissingEdge(e, target, cause));
                    }
                }
                break;
        }
        i++;
    }
    // add missing edges
    for (MissingEdge p : missingEdges) {
        Integer index = p.index;
        assert index != null : "CFGBuilder: problem in CFG construction " + p.source;
        ExtendedNode extendedNode = nodeList.get(index);
        BlockImpl target = extendedNode.getBlock();
        SingleSuccessorBlockImpl source = p.source;
        source.setSuccessor(target);
        if (p.flowRule != null) {
            source.setFlowRule(p.flowRule);
        }
    }
    // add missing exceptional edges
    for (MissingEdge p : missingExceptionalEdges) {
        Integer index = p.index;
        TypeMirror cause = p.cause;
        ExceptionBlockImpl source = (ExceptionBlockImpl) p.source;
        if (index == null) {
            // edge to exceptional exit
            source.addExceptionalSuccessor(exceptionalExitBlock, cause);
        } else {
            // edge to specific target
            ExtendedNode extendedNode = nodeList.get(index);
            BlockImpl target = extendedNode.getBlock();
            source.addExceptionalSuccessor(target, cause);
        }
    }
    return new ControlFlowGraph(startBlock, regularExitBlock, exceptionalExitBlock, in.underlyingAST, in.treeLookupMap, in.convertedTreeLookupMap, in.unaryAssignNodeLookupMap, in.returnNodes, in.declaredClasses, in.declaredLambdas);
}