better support LineBinding

bytekit/src/main/java/com/taobao/arthas/bytekit/asm/binding/Binding.java

@@ -313,27 +313,33 @@ public abstract class Binding {
         }
         
     }
-    
-    
+
+
     @Documented
     @Retention(RetentionPolicy.RUNTIME)
     @java.lang.annotation.Target(ElementType.PARAMETER)
     @BindingParserHandler(parser = LineBindingParser.class)
     public static @interface Line {
-        
         boolean optional() default false;
 
+        /**
+         * 是否精确是在某个 LineNumberNode 上。如果为true的话，会向上找到最接近的 LineNumberNode
+         * 
+         * @return
+         */
+        boolean exact() default false;
+
     }
-    
+
     public static class LineBindingParser implements BindingParser {
         @Override
         public Binding parse(Annotation annotation) {
-            return new LineBinding();
+            Line line = (Line) annotation;
+            return new LineBinding(line.exact());
         }
-        
     }
-    
-    
+
+
     @Documented
     @Retention(RetentionPolicy.RUNTIME)
     @java.lang.annotation.Target(ElementType.PARAMETER)

bytekit/src/main/java/com/taobao/arthas/bytekit/asm/binding/LineBinding.java

@@ -8,17 +8,38 @@ import com.alibaba.arthas.deps.org.objectweb.asm.tree.LineNumberNode;
 import com.taobao.arthas.bytekit.asm.location.Location;
 import com.taobao.arthas.bytekit.utils.AsmOpUtils;
 
+/**
+ * 
+ * @author hengyunabc
+ *
+ */
 public class LineBinding extends Binding {
 
+    private boolean exact;
+
+    public LineBinding(boolean exact) {
+        this.exact = exact;
+    }
+
     @Override
     public void pushOntoStack(InsnList instructions, BindingContext bindingContext) {
         Location location = bindingContext.getLocation();
         AbstractInsnNode insnNode = location.getInsnNode();
 
-        if (insnNode instanceof LineNumberNode) {
-            AsmOpUtils.push(instructions, ((LineNumberNode) insnNode).line);
+        if (exact) {
+            if (insnNode instanceof LineNumberNode) {
+                AsmOpUtils.push(instructions, ((LineNumberNode) insnNode).line);
+            } else {
+                throw new IllegalArgumentException("LineBinding location is not LineNumberNode, insnNode: " + insnNode);
+            }
         } else {
-            throw new IllegalArgumentException("LineBinding location is not LineNumberNode, insnNode: " + insnNode);
+            while (insnNode != null) {
+                if (insnNode instanceof LineNumberNode) {
+                    AsmOpUtils.push(instructions, ((LineNumberNode) insnNode).line);
+                    break;
+                }
+                insnNode = insnNode.getPrevious();
+            }
         }
     }
 

bytekit/src/test/java/com/taobao/arthas/bytekit/asm/interceptor/AtInvokeTest.java

@@ -28,6 +28,7 @@ public class AtInvokeTest {
         public int testCall(int ii) {
             toBeCall(ii, 123L, "");
             System.err.println("abc");
+
             aaa("abc");
             return 123;
         }
@@ -60,10 +61,12 @@ public class AtInvokeTest {
         public static void onInvoke(
                 @Binding.This Object object,
                 @Binding.Class Object clazz
-                ,  
+                , 
+                @Binding.Line int line,
                 @Binding.InvokeArgs Object[] args
                 ) {
-            System.err.println("onInvoke: this" + object);
+            System.err.println("onInvoke: line: " + line);
+            System.err.println("onInvoke: this: " + object);
         }
         
         @AtInvoke(name = "toBeCall", inline = false, whenComplete = true)