01 /**
02 * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
03 */
04 package net.sourceforge.pmd.lang.dfa;
05
06 import java.util.ArrayList;
07 import java.util.List;
08 import java.util.Stack;
09
10 import net.sourceforge.pmd.lang.DataFlowHandler;
11 import net.sourceforge.pmd.lang.ast.Node;
12
13 /**
14 * @author raik
15 * <p/>
16 * Structure contains only raw data. A set of nodes which represent a data flow
17 * and 2 stacks to link the nodes to each other.
18 */
19 public class Structure {
20
21 private final DataFlowHandler dataFlowHandler;
22 private List<DataFlowNode> dataFlow = new ArrayList<DataFlowNode>();
23 private Stack<StackObject> braceStack = new Stack<StackObject>();
24 private Stack<StackObject> continueBreakReturnStack = new Stack<StackObject>();
25
26 public Structure(DataFlowHandler dataFlowHandler) {
27 this.dataFlowHandler = dataFlowHandler;
28 }
29
30 /**
31 * This class encapsulates the access to the DataFlowNode class. Is this worthwhile?
32 * TODO I think it's too confusing to have the DataFlowNode constructor
33 * add the created instance to the List. I think it'd be clearer if we did
34 * that more "procedurally", i.e., create the object, then add it to the list.
35 */
36 public DataFlowNode createNewNode(Node node) {
37 return dataFlowHandler.createDataFlowNode(dataFlow, node);
38 }
39
40 public DataFlowNode createStartNode(int line) {
41 return new StartOrEndDataFlowNode(this.dataFlow, line, true);
42 }
43
44 public DataFlowNode createEndNode(int line) {
45 return new StartOrEndDataFlowNode(this.dataFlow, line, false);
46 }
47
48 public DataFlowNode getLast() {
49 return this.dataFlow.get(this.dataFlow.size() - 1);
50 }
51
52 public DataFlowNode getFirst() {
53 return this.dataFlow.get(0);
54 }
55
56 // ----------------------------------------------------------------------------
57 // STACK FUNCTIONS
58
59 /**
60 * The braceStack contains all nodes which are important to link the data
61 * flow nodes. The cbrStack contains continue, break, and return nodes.
62 * There are 2 Stacks because the have to process differently.
63 */
64 public void pushOnStack(int type, DataFlowNode node) {
65 StackObject obj = new StackObject(type, node);
66 if (type == NodeType.RETURN_STATEMENT || type == NodeType.BREAK_STATEMENT
67 || type == NodeType.CONTINUE_STATEMENT || type == NodeType.THROW_STATEMENT) {
68 // ugly solution - stores the type information in two ways
69 continueBreakReturnStack.push(obj);
70 } else {
71 braceStack.push(obj);
72 }
73 node.setType(type);
74 }
75
76 public List<StackObject> getBraceStack() {
77 return braceStack;
78 }
79
80 public List<StackObject> getContinueBreakReturnStack() {
81 return continueBreakReturnStack;
82 }
83
84 }
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