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package org.checkerframework.framework.flow;
import com.sun.source.tree.AssertTree;
import com.sun.source.tree.CompilationUnitTree;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.Tree;
import com.sun.source.tree.VariableTree;
import com.sun.source.util.TreePath;
import org.checkerframework.common.basetype.BaseTypeChecker;
import org.checkerframework.dataflow.cfg.ControlFlowGraph;
import org.checkerframework.dataflow.cfg.UnderlyingAST;
import org.checkerframework.dataflow.cfg.builder.CFGBuilder;
import org.checkerframework.dataflow.cfg.builder.CFGTranslationPhaseOne;
import org.checkerframework.dataflow.cfg.builder.CFGTranslationPhaseThree;
import org.checkerframework.dataflow.cfg.builder.CFGTranslationPhaseTwo;
import org.checkerframework.dataflow.cfg.builder.PhaseOneResult;
import org.checkerframework.framework.type.AnnotatedTypeFactory;
import org.checkerframework.framework.type.AnnotatedTypeMirror;
import org.checkerframework.framework.type.GenericAnnotatedTypeFactory;
import org.checkerframework.javacutil.ElementUtils;
import org.checkerframework.javacutil.TreeUtils;
import org.checkerframework.javacutil.UserError;
import java.util.Collection;
import javax.annotation.processing.ProcessingEnvironment;
import javax.lang.model.element.Element;
import javax.lang.model.element.VariableElement;
import javax.lang.model.type.ArrayType;
import javax.lang.model.type.TypeKind;
import javax.lang.model.type.TypeMirror;
/**
* A control-flow graph builder (see {@link CFGBuilder}) that knows about the Checker Framework
* annotations and their representation as {@link AnnotatedTypeMirror}s.
*/
public class CFCFGBuilder extends CFGBuilder {
/** This class should never be instantiated. Protected to still allow subclasses. */
protected CFCFGBuilder() {}
/** Build the control flow graph of some code. */
public static ControlFlowGraph build(
CompilationUnitTree root,
UnderlyingAST underlyingAST,
BaseTypeChecker checker,
AnnotatedTypeFactory atypeFactory,
ProcessingEnvironment env) {
boolean assumeAssertionsEnabled = checker.hasOption("assumeAssertionsAreEnabled");
boolean assumeAssertionsDisabled = checker.hasOption("assumeAssertionsAreDisabled");
if (assumeAssertionsEnabled && assumeAssertionsDisabled) {
throw new UserError(
"Assertions cannot be assumed to be enabled and disabled at the same time.");
}
// Subcheckers with dataflow share control-flow graph structure to
// allow a super-checker to query the stores of a subchecker.
if (atypeFactory instanceof GenericAnnotatedTypeFactory) {
GenericAnnotatedTypeFactory asGATF =
(GenericAnnotatedTypeFactory) atypeFactory;
if (asGATF.hasOrIsSubchecker) {
ControlFlowGraph sharedCFG = asGATF.getSharedCFGForTree(underlyingAST.getCode());
if (sharedCFG != null) {
return sharedCFG;
}
}
}
CFTreeBuilder builder = new CFTreeBuilder(env);
PhaseOneResult phase1result =
new CFCFGTranslationPhaseOne(
builder,
checker,
atypeFactory,
assumeAssertionsEnabled,
assumeAssertionsDisabled,
env)
.process(root, underlyingAST);
ControlFlowGraph phase2result = CFGTranslationPhaseTwo.process(phase1result);
ControlFlowGraph phase3result = CFGTranslationPhaseThree.process(phase2result);
if (atypeFactory instanceof GenericAnnotatedTypeFactory) {
GenericAnnotatedTypeFactory asGATF =
(GenericAnnotatedTypeFactory) atypeFactory;
if (asGATF.hasOrIsSubchecker) {
asGATF.addSharedCFGForTree(underlyingAST.getCode(), phase3result);
}
}
return phase3result;
}
/**
* Given a SourceChecker and an AssertTree, returns whether the AssertTree uses
* an @AssumeAssertion string that is relevant to the SourceChecker.
*
* @param checker the checker
* @param tree an assert tree
* @return true if the assert tree contains an @AssumeAssertion(checker) message string for any
* subchecker of the given checker's ultimate parent checker
*/
public static boolean assumeAssertionsActivatedForAssertTree(
BaseTypeChecker checker, AssertTree tree) {
ExpressionTree detail = tree.getDetail();
if (detail != null) {
String msg = detail.toString();
BaseTypeChecker ultimateParent = checker.getUltimateParentChecker();
Collection prefixes = ultimateParent.getSuppressWarningsPrefixesOfSubcheckers();
for (String prefix : prefixes) {
String assumeAssert = "@AssumeAssertion(" + prefix + ")";
if (msg.contains(assumeAssert)) {
return true;
}
}
}
return false;
}
/**
* A specialized phase-one CFG builder, with a few modifications that make use of the type
* factory. It is responsible for: 1) translating foreach loops so that the declarations of
* their iteration variables have the right annotations, 2) registering the containing elements
* of artificial trees with the relevant type factories, and 3) generating appropriate assertion
* CFG structure in the presence of @AssumeAssertion assertion strings which mention the checker
* or its supercheckers.
*/
protected static class CFCFGTranslationPhaseOne extends CFGTranslationPhaseOne {
/** The associated checker. */
protected final BaseTypeChecker checker;
/** Type factory to provide types used during CFG building. */
protected final AnnotatedTypeFactory atypeFactory;
public CFCFGTranslationPhaseOne(
CFTreeBuilder builder,
BaseTypeChecker checker,
AnnotatedTypeFactory atypeFactory,
boolean assumeAssertionsEnabled,
boolean assumeAssertionsDisabled,
ProcessingEnvironment env) {
super(builder, atypeFactory, assumeAssertionsEnabled, assumeAssertionsDisabled, env);
this.checker = checker;
this.atypeFactory = atypeFactory;
}
@Override
protected boolean assumeAssertionsEnabledFor(AssertTree tree) {
if (assumeAssertionsActivatedForAssertTree(checker, tree)) {
return true;
}
return super.assumeAssertionsEnabledFor(tree);
}
/**
* {@inheritDoc}
*
* Assigns a path to the artificial tree.
*
* @param tree the newly created Tree
*/
@Override
public void handleArtificialTree(Tree tree) {
// Create a new child of the current path and assign to the artificial tree.
// Although intuitively, using the sibling of the current path as the artificial tree
// path makes more sense, it has the risk of improperly changing the defaulting scope
// of the artificial tree.
TreePath artificialPath = new TreePath(getCurrentPath(), tree);
atypeFactory.setPathForArtificialTree(tree, artificialPath);
}
@Override
protected VariableTree createEnhancedForLoopIteratorVariable(
MethodInvocationTree iteratorCall, VariableElement variableElement) {
Tree annotatedIteratorTypeTree =
((CFTreeBuilder) treeBuilder)
.buildAnnotatedType(TreeUtils.typeOf(iteratorCall));
handleArtificialTree(annotatedIteratorTypeTree);
// Declare and initialize a new, unique iterator variable
VariableTree iteratorVariable =
treeBuilder.buildVariableDecl(
annotatedIteratorTypeTree,
uniqueName("iter"),
variableElement.getEnclosingElement(),
iteratorCall);
return iteratorVariable;
}
@Override
protected VariableTree createEnhancedForLoopArrayVariable(
ExpressionTree expression, VariableElement variableElement) {
TypeMirror type = null;
if (TreeUtils.isLocalVariable(expression)) {
// It is necessary to get the elt because just getting the type of expression
// directly (via TreeUtils.typeOf) doesn't include annotations on the declarations
// of local variables, for some reason.
Element elt = TreeUtils.elementFromTree(expression);
if (elt != null) {
type = ElementUtils.getType(elt);
}
}
// In all other cases, instead get the type of the expression. This case is
// also triggered when the type from the element is not an array, which can occur
// if the declaration of the local is a generic, such as in
// framework/tests/all-systems/java8inference/Issue1775.java.
// Getting the type from the expression itself guarantees the result will be an array.
if (type == null || type.getKind() != TypeKind.ARRAY) {
TypeMirror expressionType = TreeUtils.typeOf(expression);
type = expressionType;
}
assert (type instanceof ArrayType) : "array types must be represented by ArrayType";
Tree annotatedArrayTypeTree = ((CFTreeBuilder) treeBuilder).buildAnnotatedType(type);
handleArtificialTree(annotatedArrayTypeTree);
// Declare and initialize a temporary array variable
VariableTree arrayVariable =
treeBuilder.buildVariableDecl(
annotatedArrayTypeTree,
uniqueName("array"),
variableElement.getEnclosingElement(),
expression);
return arrayVariable;
}
}
}