Fix SourceInterpreter wrongly saying that Condy long / doubles are one word elements.

Author: Constantin C

asm-analysis/src/main/java/org/objectweb/asm/tree/analysis/SourceInterpreter.java

@@ -30,6 +30,7 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import org.objectweb.asm.ConstantDynamic;
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.Type;
 import org.objectweb.asm.tree.AbstractInsnNode;
@@ -86,8 +87,22 @@ public SourceValue newOperation(final AbstractInsnNode insn) {
         size = 2;
         break;
       case LDC:
+        // Values able to be pushed by LDC:
+        //   - int, float, string (object), type (Class, object), type (MethodType, object),
+        //       handle (MethodHandle, object): one word
+        //   - long, double, ConstantDynamic (can produce either single word values, or double word
+        //       values): (up to) two words
         Object value = ((LdcInsnNode) insn).cst;
-        size = value instanceof Long || value instanceof Double ? 2 : 1;
+        if (value instanceof Long || value instanceof Double) {
+          // two words guaranteed
+          size = 2;
+        } else if (value instanceof ConstantDynamic) {
+          // might yield two words
+          size = ((ConstantDynamic) value).getSize();
+        } else {
+          // one word guaranteed
+          size = 1;
+        }
         break;
       case GETSTATIC:
         size = Type.getType(((FieldInsnNode) insn).desc).getSize();

asm-test/src/main/resources/jdk11/AllInstructions.class

@@ -85,6 +85,31 @@ private static Method bsm:"(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/St
   lreturn;
 }
 
+// Needed to make two since asmtools' jasm doesnt optimize bsm entries the same way we do.
+// -> asmtools would generate two bsm methods, ClassWriter would generate one with the input from asmtools.
+// -> test fails while technically being correct
+private static Method anotherBsm:"(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/Class;)J"
+  stack 2 locals 3
+{
+  bipush 42;
+  i2l;
+  lreturn;
+}
+
+public static Method gnarlyCondyPop:"()V"
+  stack 2 locals 0
+{
+    ldc2_w  Dynamic REF_invokeStatic
+        :jdk11/AllInstructions.anotherBsm
+        :"(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/Class;)J"
+        :test
+        :"J";
+    // Test that a condy ldc (interpreted as an ldc of a ConstantDynamic object) yields
+    //  a value with the proper size, as indicated by its descriptor (long in this case, 2 words)
+    pop2;
+    return;
+}
+
 public static Method main:"([Ljava/lang/String;)V"
   stack 1 locals 2
 {

asm-test/src/resources/java/jdk11/AllInstructions.jasm

@@ -50,6 +50,26 @@ public class jdk11/AllInstructions {
     MAXSTACK = 2
     MAXLOCALS = 3
 
+  // access flags 0xA
+  private static anotherBsm(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/Class;)J
+    BIPUSH 42
+    I2L
+    LRETURN
+    MAXSTACK = 2
+    MAXLOCALS = 3
+
+  // access flags 0x9
+  public static gnarlyCondyPop()V
+    LDC test : J [
+      // handle kind 0x6 : INVOKESTATIC
+      jdk11/AllInstructions.anotherBsm(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/Class;)J
+      // arguments: none
+    ]
+    POP2
+    RETURN
+    MAXSTACK = 2
+    MAXLOCALS = 0
+
   // access flags 0x9
   public static main([Ljava/lang/String;)V
     LDC run : Ljava/lang/Runnable; [