package org.checkerframework.checker.nullness;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.LiteralTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.Tree;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import javax.annotation.processing.ProcessingEnvironment;
import javax.lang.model.element.ExecutableElement;
import org.checkerframework.framework.type.AnnotatedTypeMirror;
import org.checkerframework.framework.type.AnnotatedTypeMirror.AnnotatedExecutableType;
import org.checkerframework.javacutil.TreeUtils;
/**
* Utility class for handling {@link java.lang.System#getProperty(String)} invocations.
*
* <p>If the argument is a literal key that is guaranteed to be present in the system properties may
* (according to the documentation of {@link java.lang.System#getProperty(String)}), as in {@code
* System.getProperties("line.separator")}, then the result of the method call is assumed to be
* non-null.
*/
public class SystemGetPropertyHandler {
protected final ProcessingEnvironment env;
protected final NullnessAnnotatedTypeFactory factory;
protected final ExecutableElement systemGetProperty;
// This list is from the Javadoc of System.getProperties.
Collection<String> systemProperties =
new HashSet<>(
Arrays.asList(
"java.version",
"java.vendor",
"java.vendor.url",
"java.home",
"java.vm.specification.version",
"java.vm.specification.vendor",
"java.vm.specification.name",
"java.vm.version",
"java.vm.vendor",
"java.vm.name",
"java.specification.version",
"java.specification.vendor",
"java.specification.name",
"java.class.version",
"java.class.path",
"java.library.path",
"java.io.tmpdir",
"java.compiler",
"java.ext.dirs",
"os.name",
"os.arch",
"os.version",
"file.separator",
"path.separator",
"line.separator",
"user.name",
"user.home",
"user.dir"));
public SystemGetPropertyHandler(
ProcessingEnvironment env, NullnessAnnotatedTypeFactory factory) {
this.env = env;
this.factory = factory;
systemGetProperty =
TreeUtils.getMethod(java.lang.System.class.getName(), "getProperty", 1, env);
}
public void handle(MethodInvocationTree tree, AnnotatedExecutableType method) {
if (TreeUtils.isMethodInvocation(tree, systemGetProperty, env)) {
List<? extends ExpressionTree> args = tree.getArguments();
assert args.size() == 1;
ExpressionTree arg = args.get(0);
if (arg.getKind() == Tree.Kind.STRING_LITERAL) {
String literal = (String) ((LiteralTree) arg).getValue();
if (systemProperties.contains(literal)) {
AnnotatedTypeMirror type = method.getReturnType();
type.replaceAnnotation(factory.NONNULL);
}
}
}
}
}