Minor improvements

dataflow/src/main/java/org/checkerframework/dataflow/analysis/AbstractAnalysis.java

@@ -431,8 +431,8 @@ protected void initFields(ControlFlowGraph cfg) {
   }
 
   /**
-   * Updates the value of node {@code node} to the value of the {@code transferResult}. Returns true
-   * if the node's value changed, or a store was updated.
+   * Updates the value of node {@code node} in {@link #nodeValues} to the value of the {@code
+   * transferResult}. Returns true if the node's value changed, or a store was updated.
    *
    * @param node the node to update
    * @param transferResult the transfer result being updated

dataflow/src/main/java/org/checkerframework/dataflow/analysis/AnalysisResult.java

@@ -213,6 +213,7 @@ public Map<VariableElement, V> getFinalLocalValues() {
    *     available
    */
   public @Nullable V getValue(Tree t) {
+    // This is a set because one Tree might correspond to multiple Nodes.
     Set<Node> nodes = treeLookup.get(t);
 
     if (nodes == null) {
@@ -221,10 +222,12 @@ public Map<VariableElement, V> getFinalLocalValues() {
     V merged = null;
     for (Node aNode : nodes) {
       V a = getValue(aNode);
-      if (merged == null) {
-        merged = a;
-      } else if (a != null) {
-        merged = merged.leastUpperBound(a);
+      if (a != null) {
+        if (merged == null) {
+          merged = a;
+        } else {
+          merged = merged.leastUpperBound(a);
+        }
       }
     }
     return merged;

docs/manual/creating-a-checker.tex

@@ -1645,8 +1645,8 @@
 relevant to your run-time check or run-time operation.
 Leave the body of the overriding method empty for now.
 
-For example, the Regex Checker refines the type of a run-time test method
-call.  A method call is represented by a
+For example, the Regex Checker refines the type based on a call to the
+\<RegexUtil.isRegex> method.  A method call is represented by a
 \refclass{dataflow/cfg/node}{MethodInvocationNode}.  Therefore,
 \refclass{checker/regex}{RegexTransfer} overrides the
 \code{visitMethodInvocation} method:

framework/src/main/java/org/checkerframework/common/basetype/BaseTypeVisitor.java

@@ -2361,12 +2361,6 @@ public Void visitAnnotation(AnnotationTree tree, Void p) {
     return null;
   }
 
-  /**
-   * If the computation of the type of the ConditionalExpressionTree in
-   * org.checkerframework.framework.type.TypeFromTree.TypeFromExpression.visitConditionalExpression(ConditionalExpressionTree,
-   * AnnotatedTypeFactory) is correct, the following checks are redundant. However, let's add
-   * another failsafe guard and do the checks.
-   */
   @Override
   public Void visitConditionalExpression(ConditionalExpressionTree tree, Void p) {
     if (TreeUtils.isPolyExpression(tree)) {
@@ -2377,6 +2371,10 @@ public Void visitConditionalExpression(ConditionalExpressionTree tree, Void p) {
       return super.visitConditionalExpression(tree, p);
     }
 
+    // If the computation of the type of the ConditionalExpressionTree in
+    // org.checkerframework.framework.type.TypeFromTree.TypeFromExpression.visitConditionalExpression(ConditionalExpressionTree,
+    // AnnotatedTypeFactory) is correct, the following checks are redundant. However, let's add
+    // another failsafe guard and do the checks.
     AnnotatedTypeMirror cond = atypeFactory.getAnnotatedType(tree);
     this.commonAssignmentCheck(cond, tree.getTrueExpression(), "conditional");
     this.commonAssignmentCheck(cond, tree.getFalseExpression(), "conditional");

framework/src/main/java/org/checkerframework/framework/type/AnnotatedTypeFactory.java

@@ -1691,8 +1691,9 @@ protected AnnotatedTypeMirror mergeAnnotationFileAnnosIntoType(
    * Creates an AnnotatedTypeMirror for an ExpressionTree. The AnnotatedTypeMirror contains explicit
    * annotations written on the expression and for some expressions, annotations from
    * sub-expressions that could have been explicitly written, defaulted, refined, or otherwise
-   * computed. (Expression whose type include annotations from sub-expressions are: ArrayAccessTree,
-   * ConditionalExpressionTree, IdentifierTree, MemberSelectTree, and MethodInvocationTree.)
+   * computed. (Expressions whose type include annotations from sub-expressions are:
+   * ArrayAccessTree, ConditionalExpressionTree, IdentifierTree, MemberSelectTree, and
+   * MethodInvocationTree.)
    *
    * <p>For example, the AnnotatedTypeMirror returned for an array access expression is the fully
    * annotated type of the array component of the array being accessed.