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POHow to avoid "Illegal type in constant pool" using "ldc_w <classname>" in Jasmin?
 

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  1. POHow to avoid "Illegal type in constant pool" using "ldc_w <classname>" in Jasmin?
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    <p>I'm writing a compiler that generates Jasmin code and want to invoke a method that takes a Class as a parameter.</p> <pre><code>public class CTest { public static void main(String[] args) throws Exception { java.lang.reflect.Array.newInstance(CTest.class, 0); } } </code></pre> <p>So in Jasmin, I think that should be:</p> <pre><code>.class public CTest2 .super java/lang/Object .method public static main([Ljava/lang/String;)V .limit stack 2 .limit locals 1 ldc_w CTest2 iconst_0 invokestatic java/lang/reflect/Array/newInstance(Ljava/lang/Class;I)Ljava/lang/Object; pop return .end method </code></pre> <p>When I assemble it and run it I get:</p> <p>Exception in thread "main" java.lang.VerifyError: (class: CTest2, method: main signature: ([Ljava/lang/String;)V) Illegal type in constant pool</p> <p>Looking at the disassembled code for both CTest.class (the Java version) and CTest2.class (the Jasmin version) with "javap -c -verbose" they both appear to set up the constant pool the same way:</p> <pre><code>const #2 = class #16; // CTest const #16 = Asciz CTest; 0: ldc_w #2; //class CTest const #14 = Asciz CTest2; const #17 = class #14; // CTest2 0: ldc_w #17; //class CTest2 </code></pre> <p>I've fixed two bugs in Jasmin already, but I can't see what it's doing wrong when putting the class in the constant pool for "ldc_w" it puts classes in the constant pool for other instructions, like "new" and "anewarray" correctly.</p> <p>I've tried looking at the .class files with TraceClassVisitor in ASM, but it doesn't dump the constant pool.</p> <p>Any ideas what I can try next?</p>
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