Examples with ThrowStatement com.google.devtools.j2objc.ast.ThrowStatement used on opensource projects

Example 1 with ThrowStatement

use of com.google.devtools.j2objc.ast.ThrowStatement in project j2objc by google.

the class Rewriter method visit.

@Override
public boolean visit(TryStatement node) {
    // This visit rewrites try-with-resources constructs into regular try statements according to
    // JLS 14.20.3. The rewriting is done in a visit instead of endVisit because the mutations may
    // result in more try-with-resources constructs that need to be rewritten recursively.
    List<TreeNode> resources = node.getResources();
    if (resources.isEmpty()) {
        return true;
    }
    if (!node.getCatchClauses().isEmpty() || node.getFinally() != null) {
        // Extended try-with-resources. (JLS 14.20.3.2)
        // The new innerTry statement will be a "Basic try-with-resources" and will be rewritten by
        // the code below when it is visited.
        TryStatement innerTry = new TryStatement().setBody(TreeUtil.remove(node.getBody()));
        ;
        TreeUtil.moveList(resources, innerTry.getResources());
        node.setBody(new Block().addStatement(innerTry));
        return true;
    }
    // Basic try-with-resources. (JLS 14.20.3.1)
    DeclaredType throwableType = (DeclaredType) typeUtil.getJavaThrowable().asType();
    VariableElement primaryException = GeneratedVariableElement.newLocalVar("__primaryException" + resources.size(), throwableType, null);
    TreeNode resource = resources.remove(0);
    VariableElement resourceVar = null;
    VariableDeclarationFragment resourceFrag = null;
    if (resource.getKind() == Kind.VARIABLE_DECLARATION_EXPRESSION) {
        List<VariableDeclarationFragment> resourceFrags = ((VariableDeclarationExpression) resource).getFragments();
        assert resourceFrags.size() == 1;
        resourceFrag = resourceFrags.get(0);
        resourceVar = resourceFrag.getVariableElement();
    } else {
        resourceVar = TreeUtil.getVariableElement((Expression) resource);
    }
    assert resourceVar != null;
    DeclaredType closeableType = typeUtil.findSupertype(resourceVar.asType(), "java.lang.AutoCloseable");
    ExecutablePair closeMethod = typeUtil.findMethod(closeableType, "close");
    ExecutablePair addSuppressedMethod = typeUtil.findMethod(throwableType, "addSuppressed", "java.lang.Throwable");
    Block block = new Block();
    if (resourceFrag != null) {
        block.addStatement(new VariableDeclarationStatement(resourceVar, TreeUtil.remove(resourceFrag.getInitializer())));
    }
    block.addStatement(new VariableDeclarationStatement(primaryException, new NullLiteral(typeUtil.getNull())));
    // If the current try node is the only statement in its parent block then replace the parent
    // block instead of the try node to avoid extra nesting of braces.
    TreeNode parent = node.getParent();
    if (parent instanceof Block && ((Block) parent).getStatements().size() == 1) {
        parent.replaceWith(block);
    } else {
        node.replaceWith(block);
    }
    block.addStatement(TreeUtil.remove(node));
    VariableElement caughtException = GeneratedVariableElement.newLocalVar("e", throwableType, null);
    Block catchBlock = new Block().addStatement(new ExpressionStatement(new Assignment(new SimpleName(primaryException), new SimpleName(caughtException)))).addStatement(new ThrowStatement(new SimpleName(caughtException)));
    node.addCatchClause(new CatchClause().setException(new SingleVariableDeclaration(caughtException)).setBody(catchBlock));
    Statement closeResource = new ExpressionStatement(new MethodInvocation(closeMethod, typeUtil.getVoid(), new SimpleName(resourceVar)));
    VariableElement suppressedException = GeneratedVariableElement.newLocalVar("e", throwableType, null);
    node.setFinally(new Block().addStatement(new IfStatement().setExpression(new InfixExpression(typeUtil.getBoolean(), InfixExpression.Operator.NOT_EQUALS, new SimpleName(resourceVar), new NullLiteral(typeUtil.getNull()))).setThenStatement(new Block().addStatement(new IfStatement().setExpression(new InfixExpression(typeUtil.getBoolean(), InfixExpression.Operator.NOT_EQUALS, new SimpleName(primaryException), new NullLiteral(typeUtil.getNull()))).setThenStatement(new Block().addStatement(new TryStatement().setBody(new Block().addStatement(closeResource)).addCatchClause(new CatchClause().setException(new SingleVariableDeclaration(suppressedException)).setBody(new Block().addStatement(new ExpressionStatement(new MethodInvocation(addSuppressedMethod, typeUtil.getVoid(), new SimpleName(primaryException)).addArgument(new SimpleName(suppressedException)))))))).setElseStatement(new Block().addStatement(closeResource.copy()))))));
    // Visit the new block instead of the current node because some of content of the node (eg. the
    // resource initializer) has been moved outside of the try node.
    block.accept(this);
    return false;
}