Added @SneakyThrows support for javac. W00t.

1 files changed, 99 insertions, 0 deletions

diff --git a/src/lombok/javac/handlers/HandleSneakyThrows.java b/src/lombok/javac/handlers/HandleSneakyThrows.java
new file mode 100644
index 00000000..b21468ee
--- /dev/null
+++ b/src/lombok/javac/handlers/HandleSneakyThrows.java
@@ -0,0 +1,99 @@
+package lombok.javac.handlers;
+
+import static lombok.javac.handlers.PKG.chainDots;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+import lombok.SneakyThrows;
+import lombok.core.AnnotationValues;
+import lombok.javac.JavacAnnotationHandler;
+import lombok.javac.JavacAST.Node;
+
+import org.mangosdk.spi.ProviderFor;
+
+import com.sun.tools.javac.code.Flags;
+import com.sun.tools.javac.tree.TreeMaker;
+import com.sun.tools.javac.tree.JCTree.JCAnnotation;
+import com.sun.tools.javac.tree.JCTree.JCAssign;
+import com.sun.tools.javac.tree.JCTree.JCBlock;
+import com.sun.tools.javac.tree.JCTree.JCExpression;
+import com.sun.tools.javac.tree.JCTree.JCMethodDecl;
+import com.sun.tools.javac.tree.JCTree.JCNewArray;
+import com.sun.tools.javac.tree.JCTree.JCStatement;
+import com.sun.tools.javac.tree.JCTree.JCVariableDecl;
+import com.sun.tools.javac.util.List;
+
+@ProviderFor(JavacAnnotationHandler.class)
+public class HandleSneakyThrows implements JavacAnnotationHandler<SneakyThrows> {
+	@Override public boolean handle(AnnotationValues<SneakyThrows> annotation, JCAnnotation ast, Node annotationNode) {
+		Collection<String> exceptionNames = annotation.getRawExpressions("value");
+		
+		List<JCExpression> memberValuePairs = ast.getArguments();
+		if ( memberValuePairs == null || memberValuePairs.size() == 0 ) return false;
+		
+		JCExpression arrayOrSingle = ((JCAssign)memberValuePairs.get(0)).rhs;
+		final List<JCExpression> exceptionNameNodes;
+		if ( arrayOrSingle instanceof JCNewArray ) {
+			exceptionNameNodes = ((JCNewArray)arrayOrSingle).elems;
+		} else exceptionNameNodes = List.of(arrayOrSingle);
+		
+		if ( exceptionNames.size() != exceptionNameNodes.size() ) {
+			annotationNode.addError(
+					"LOMBOK BUG: The number of exception classes in the annotation isn't the same pre- and post- guessing.");
+		}
+		
+		java.util.List<String> exceptions = new ArrayList<String>();
+		for ( String exception : exceptionNames ) {
+			if ( exception.endsWith(".class") ) exception = exception.substring(0, exception.length() - 6);
+			exceptions.add(exception);
+		}
+		
+		Node owner = annotationNode.up();
+		switch ( owner.getKind() ) {
+		case METHOD:
+			return handleMethod(annotationNode, (JCMethodDecl)owner.get(), exceptions);
+		default:
+			annotationNode.addError("@SneakyThrows is legal only on methods and constructors.");
+			return true;
+		}
+	}
+	
+	private boolean handleMethod(Node annotation, JCMethodDecl method, Collection<String> exceptions) {
+		Node methodNode = annotation.up();
+		
+		if ( (method.mods.flags & Flags.ABSTRACT) != 0 ) {
+			annotation.addError("@SneakyThrows can only be used on concrete methods.");
+			return true;
+		}
+		
+		if ( method.body == null ) return false;
+		
+		List<JCStatement> contents = method.body.stats;
+		
+		for ( String exception : exceptions ) {
+			contents = List.of(buildTryCatchBlock(methodNode, contents, exception));
+		}
+		
+		method.body.stats = contents;
+		methodNode.rebuild();
+		
+		return true;
+	}
+
+	private JCStatement buildTryCatchBlock(Node node, List<JCStatement> contents, String exception) {
+		TreeMaker maker = node.getTreeMaker();
+		
+		JCBlock tryBlock = maker.Block(0, contents);
+		
+		JCExpression varType = chainDots(maker, node, exception.split("\\."));
+		
+		JCVariableDecl catchParam = maker.VarDef(maker.Modifiers(0), node.toName("$ex"), varType, null);
+		JCExpression lombokLombokSneakyThrowNameRef = chainDots(maker, node, "lombok", "Lombok", "sneakyThrow");
+		JCBlock catchBody = maker.Block(0, List.<JCStatement>of(maker.Throw(maker.Apply(
+				List.<JCExpression>nil(), lombokLombokSneakyThrowNameRef,
+				List.<JCExpression>of(maker.Ident(node.toName("$ex")))))));
+		
+		return maker.Try(tryBlock, List.of(maker.Catch(catchParam, catchBody)), null);
+	}
+}