fixup! Add getControlFlowGraph() to relevant node impls

Author: jgardn3r

delphi-frontend/src/main/java/au/com/integradev/delphi/cfg/ControlFlowGraphVisitor.java

@@ -361,14 +361,14 @@ public ControlFlowGraphBuilder visit(CaseStatementNode node, ControlFlowGraphBui
 
     Set<ProtoBlock> caseSuccessors = new HashSet<>();
 
+    // If none of the case arms match, it will either skip the block, or
+    // fallthrough to an `else` block
+    ProtoBlock fallthrough = after;
     // Else
     if (node.getElseBlockNode() != null) {
       builder.addBlockBefore(after);
       build(node.getElseBlockNode().getStatementList(), builder);
-      caseSuccessors.add(builder.getCurrentBlock());
-    } else {
-      // If there is no `else` block the statement can be jumped
-      caseSuccessors.add(after);
+      fallthrough = builder.getCurrentBlock();
     }
 
     // Cases
@@ -382,7 +382,7 @@ public ControlFlowGraphBuilder visit(CaseStatementNode node, ControlFlowGraphBui
       caseSuccessors.add(builder.getCurrentBlock());
     }
 
-    caseBlock.update(ProtoBlockFactory.cases(node, caseSuccessors));
+    caseBlock.update(ProtoBlockFactory.cases(node, caseSuccessors, fallthrough));
     builder.setCurrentBlock(conditionBlock);
     return builder;
   }

delphi-frontend/src/main/java/au/com/integradev/delphi/cfg/api/Cases.java

@@ -29,6 +29,13 @@ public interface Cases extends Block, Terminated {
    */
   Set<Block> getCaseSuccessors();
 
+  /**
+   * Either the fallthrough {@code else} block or the next block in the {@link ControlFlowGraph}
+   *
+   * @return the fallthrough successor
+   */
+  Block getFallthroughSuccessor();
+
   @Override
   default Set<Block> getSuccessors() {
     return getCaseSuccessors();

delphi-frontend/src/main/java/au/com/integradev/delphi/cfg/block/ProtoBlockFactory.java

@@ -86,12 +86,16 @@ public static ProtoBlock withExceptions(ProtoBlock successor, Set<ProtoBlock> ex
                     exceptions.stream().map(blocks::get).collect(Collectors.toSet())));
   }
 
-  public static ProtoBlock cases(DelphiNode terminator, Set<ProtoBlock> cases) {
+  public static ProtoBlock cases(
+      DelphiNode terminator, Set<ProtoBlock> cases, ProtoBlock fallthrough) {
     return new ProtoBlock(
         CasesImpl::new,
         (blocks, block) ->
             ((CasesImpl) block)
-                .setData(terminator, cases.stream().map(blocks::get).collect(Collectors.toSet())));
+                .setData(
+                    terminator,
+                    cases.stream().map(blocks::get).collect(Collectors.toSet()),
+                    blocks.get(fallthrough)));
   }
 
   private static String getBlocksString(Collection<Block> block) {
@@ -144,21 +148,28 @@ public String getDescription() {
   static class CasesImpl extends BlockImpl implements Cases {
     private Terminator terminator;
     private Set<Block> cases;
+    private Block fallthrough;
 
     public CasesImpl(List<DelphiNode> elements) {
       super(elements);
     }
 
-    private void setData(DelphiNode terminator, Set<Block> cases) {
+    private void setData(DelphiNode terminator, Set<Block> cases, Block fallthrough) {
       this.terminator = new Terminator(terminator);
       this.cases = cases;
+      this.fallthrough = fallthrough;
     }
 
     @Override
     public Set<Block> getCaseSuccessors() {
       return Collections.unmodifiableSet(cases);
     }
 
+    @Override
+    public Block getFallthroughSuccessor() {
+      return fallthrough;
+    }
+
     @Override
     public DelphiNode getTerminator() {
       return terminator.getTerminatorNode();
@@ -174,11 +185,14 @@ public void replaceInactiveSuccessor(Block inactiveBlock, Block target) {
       if (cases.remove(inactiveBlock)) {
         cases.add(target);
       }
+      this.fallthrough = getNewTarget(this.fallthrough, inactiveBlock, target);
     }
 
     @Override
     public String getDescription() {
-      return String.format("%n\tcases to: %s", getBlocksString(cases));
+      return String.format(
+          "%n\tcases to: %s%n\tfallthrough to: %s",
+          getBlocksString(cases), getBlockString(fallthrough));
     }
   }
 

delphi-frontend/src/test/java/au/com/integradev/delphi/cfg/checker/BlockChecker.java

@@ -164,7 +164,7 @@ public BlockChecker jumpsTo(int successor, int successorWithoutJump) {
     return this;
   }
 
-  public BlockChecker succeedsToCases(int... cases) {
+  public BlockChecker succeedsToCases(int fallthrough, int... cases) {
     Set<Integer> expectedCases = Arrays.stream(cases).boxed().collect(Collectors.toSet());
     this.successorChecker =
         new BlockDetailChecker(
@@ -183,6 +183,12 @@ public BlockChecker succeedsToCases(int... cases) {
                               .collect(Collectors.joining(", "))
                           + "]")
                   .containsExactlyInAnyOrderElementsOf(expectedCases);
+              assertThat(getBlockId(caseSuccessor.getFallthroughSuccessor()))
+                  .withFailMessage(
+                      getBlockDisplay(block)
+                          + " is expected to have fallthrough successor of B"
+                          + fallthrough)
+                  .isEqualTo(fallthrough);
             });
     return this;
   }