gistfile1.txt

I've got this Ceylon source:

```
class C() {
    shared void m(String staticArg) {
        print("Greeting: " + staticArg);
    }
    for (i in 0..1) {
        m("");
    }
    
}
```

Rather than using `Apply()` to generate the call to `m("")`, I'm using a `JCTree.JCIndy`, so the code looks a little like this:

```
resultExpr = gen.makeIndy(actualPrimExpr, // explicitly passing this
    selector,  // the method name, m
    args.toList().append(gen.makeBoolean(true)), // Adding an extra argument
    MhKind.INVOKE_STATIC, // The bootstrap method (bsm) is to be called using invokestatic
    gen.makeQuotedFQIdent("com.redhat.ceylon.compiler.java.Bsms.bsm"), // The name of the bsm
    List.<JCExpression>of(gen.make().Literal("hello, world"))); // static arguments for the bsm
```

The generated Java looks like this:

```
package com.redhat.ceylon.compiler.java.test.structure;

class C {
    
    public final void m(final .java.lang.String staticArg) {
        .ceylon.language.print.print(.ceylon.language.String.instance("Greeting: " + staticArg));
    }
    
    C() {
        .java.lang.Object $elem$0;
        for (.ceylon.language.Iterator<? extends .ceylon.language.Integer> $i$iter$1 = new .ceylon.language.Range<.ceylon.language.Integer>(.ceylon.language.Integer.instance(0L), .ceylon.language.Integer.instance(1L)).getIterator(); !(($elem$0 = $i$iter$1.next()) instanceof .ceylon.language.Finished); ) {
            final long i = ((.ceylon.language.Integer)$elem$0).longValue();
            Indy[#.com.redhat.ceylon.compiler.java.Bsms.bsm(null, null, null, null), "hello, world"].m(this, "", true);
        }
    }
    
    public static void main(.java.lang.String[] args) {
        .ceylon.language.process.getProcess().setupArguments(args);
        new .com.redhat.ceylon.compiler.java.test.structure.C();
    }
}
```

So there is a single dynamic callsite, which we'll hit twice:

   Indy[#.com.redhat.ceylon.compiler.java.Bsms.bsm(null, null, null, null), "hello, world"].m(this, "", true);

This text representation is a little ropey. The [#...] bit specifies the BSM with its static arguments. I'm actually cheating here: The `JCIndy` actually contains an `Apply` to the BSM (with the null arguments you see above). I do this so that in the attribution phase of javac I can easily resolve the BSM so it's sufficiently attributed to generate the classfile correctly. I've not yet tried using all the various kinds of static arguments permitted.

The BSM itself looks like this:

```
public class Bsms {

    private Bsms(){}
    
    public static CallSite bsm(MethodHandles.Lookup lookup, String methodName, MethodType methodType, String sa1) throws Exception {
        System.err.println("bsm");
        System.err.println(" lookup:   " +lookup);
        System.err.println(" methodName:  "+ methodName);
        System.err.println(" methodType:  "+ methodType);
        System.err.println(" sa1: "+ sa1);
        MethodHandle mh = lookup.findVirtual(lookup.lookupClass(), "m", MethodType.methodType(Void.TYPE, new Class[]{String.class}));
        
        mh = MethodHandles.insertArguments(mh, 1, sa1);
        mh = MethodHandles.dropArguments(mh, 1, String.class);
        mh = MethodHandles.dropArguments(mh, 2, Boolean.TYPE);
        final ConstantCallSite cs = new ConstantCallSite(mh);
        return cs;
    }
    
}
```

Basically we true the boolean argument, and replace the String argument specified at the callsite with the static argument that was passed to the BSM.

Just in case you're interested the disassembled .class file looks like this:

```
$ ~/jdk1.7.0/bin/javap -c -v -s -p -classpath build/test-cars/structure/default/default.jar com.redhat.ceylon.compiler.java.test.structure.C
Classfile jar:file:/home/tom/ceylon/ceylon-compiler/build/test-cars/structure/default/default.jar!/com/redhat/ceylon/compiler/java/test/structure/C.class
  Last modified 02-Jun-2012; size 1770 bytes
  MD5 checksum ff9e86907173af28d4731af99b2e0455
  Compiled from "Indy.ceylon"
class com.redhat.ceylon.compiler.java.test.structure.C
  SourceFile: "Indy.ceylon"
  BootstrapMethods:
    0: #39 invokestatic com/redhat/ceylon/compiler/java/Bsms.bsm:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;)Ljava/lang/invoke/CallSite;
      Method arguments:
        #40 hello, world
  InnerClasses:
       public static final #97= #96 of #100; //Lookup=class java/lang/invoke/MethodHandles$Lookup of class java/lang/invoke/MethodHandles
  minor version: 0
  major version: 51
  flags: ACC_SUPER
Constant pool:
    #1 = Class              #41           //  java/lang/StringBuilder
    #2 = Methodref          #1.#42        //  java/lang/StringBuilder."<init>":()V
    #3 = String             #43           //  Greeting: 
    #4 = Methodref          #1.#44        //  java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
    #5 = Methodref          #1.#45        //  java/lang/StringBuilder.toString:()Ljava/lang/String;
    #6 = Methodref          #46.#47       //  ceylon/language/String.instance:(Ljava/lang/String;)Lceylon/language/String;
    #7 = Methodref          #48.#49       //  ceylon/language/print.print:(Ljava/lang/Object;)V
    #8 = Methodref          #23.#42       //  java/lang/Object."<init>":()V
    #9 = Class              #50           //  ceylon/language/Range
   #10 = Methodref          #15.#51       //  ceylon/language/Integer.instance:(J)Lceylon/language/Integer;
   #11 = Methodref          #9.#52        //  ceylon/language/Range."<init>":(Lceylon/language/Comparable;Lceylon/language/Comparable;)V
   #12 = Methodref          #9.#53        //  ceylon/language/Range.getIterator:()Lceylon/language/Iterator;
   #13 = InterfaceMethodref #54.#55       //  ceylon/language/Iterator.next:()Ljava/lang/Object;
   #14 = Class              #56           //  ceylon/language/Finished
   #15 = Class              #57           //  ceylon/language/Integer
   #16 = Methodref          #15.#58       //  ceylon/language/Integer.longValue:()J
   #17 = String             #59           //  
   #18 = InvokeDynamic      #0:#60        //  #0:m:(Lcom/redhat/ceylon/compiler/java/test/structure/C;Ljava/lang/String;Z)V
   #19 = Methodref          #61.#62       //  ceylon/language/process.getProcess:()Lceylon/language/process;
   #20 = Methodref          #61.#63       //  ceylon/language/process.setupArguments:([Ljava/lang/String;)V
   #21 = Class              #64           //  com/redhat/ceylon/compiler/java/test/structure/C
   #22 = Methodref          #21.#42       //  com/redhat/ceylon/compiler/java/test/structure/C."<init>":()V
   #23 = Class              #65           //  java/lang/Object
   #24 = Utf8               m
   #25 = Utf8               (Ljava/lang/String;)V
   #26 = Utf8               Code
   #27 = Utf8               LineNumberTable
   #28 = Utf8               <init>
   #29 = Utf8               ()V
   #30 = Utf8               StackMapTable
   #31 = Class              #64           //  com/redhat/ceylon/compiler/java/test/structure/C
   #32 = Class              #66           //  ceylon/language/Iterator
   #33 = Class              #65           //  java/lang/Object
   #34 = Utf8               main
   #35 = Utf8               ([Ljava/lang/String;)V
   #36 = Utf8               SourceFile
   #37 = Utf8               Indy.ceylon
   #38 = Utf8               BootstrapMethods
   #39 = MethodHandle       #6:#67        //  invokestatic com/redhat/ceylon/compiler/java/Bsms.bsm:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;)Ljava/lang/invoke/CallSite;
   #40 = String             #68           //  hello, world
   #41 = Utf8               java/lang/StringBuilder
   #42 = NameAndType        #28:#29       //  "<init>":()V
   #43 = Utf8               Greeting: 
   #44 = NameAndType        #69:#70       //  append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
   #45 = NameAndType        #71:#72       //  toString:()Ljava/lang/String;
   #46 = Class              #73           //  ceylon/language/String
   #47 = NameAndType        #74:#75       //  instance:(Ljava/lang/String;)Lceylon/language/String;
   #48 = Class              #76           //  ceylon/language/print
   #49 = NameAndType        #77:#78       //  print:(Ljava/lang/Object;)V
   #50 = Utf8               ceylon/language/Range
   #51 = NameAndType        #74:#79       //  instance:(J)Lceylon/language/Integer;
   #52 = NameAndType        #28:#80       //  "<init>":(Lceylon/language/Comparable;Lceylon/language/Comparable;)V
   #53 = NameAndType        #81:#82       //  getIterator:()Lceylon/language/Iterator;
   #54 = Class              #66           //  ceylon/language/Iterator
   #55 = NameAndType        #83:#84       //  next:()Ljava/lang/Object;
   #56 = Utf8               ceylon/language/Finished
   #57 = Utf8               ceylon/language/Integer
   #58 = NameAndType        #85:#86       //  longValue:()J
   #59 = Utf8               
   #60 = NameAndType        #24:#87       //  m:(Lcom/redhat/ceylon/compiler/java/test/structure/C;Ljava/lang/String;Z)V
   #61 = Class              #88           //  ceylon/language/process
   #62 = NameAndType        #89:#90       //  getProcess:()Lceylon/language/process;
   #63 = NameAndType        #91:#35       //  setupArguments:([Ljava/lang/String;)V
   #64 = Utf8               com/redhat/ceylon/compiler/java/test/structure/C
   #65 = Utf8               java/lang/Object
   #66 = Utf8               ceylon/language/Iterator
   #67 = Methodref          #92.#93       //  com/redhat/ceylon/compiler/java/Bsms.bsm:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;)Ljava/lang/invoke/CallSite;
   #68 = Utf8               hello, world
   #69 = Utf8               append
   #70 = Utf8               (Ljava/lang/String;)Ljava/lang/StringBuilder;
   #71 = Utf8               toString
   #72 = Utf8               ()Ljava/lang/String;
   #73 = Utf8               ceylon/language/String
   #74 = Utf8               instance
   #75 = Utf8               (Ljava/lang/String;)Lceylon/language/String;
   #76 = Utf8               ceylon/language/print
   #77 = Utf8               print
   #78 = Utf8               (Ljava/lang/Object;)V
   #79 = Utf8               (J)Lceylon/language/Integer;
   #80 = Utf8               (Lceylon/language/Comparable;Lceylon/language/Comparable;)V
   #81 = Utf8               getIterator
   #82 = Utf8               ()Lceylon/language/Iterator;
   #83 = Utf8               next
   #84 = Utf8               ()Ljava/lang/Object;
   #85 = Utf8               longValue
   #86 = Utf8               ()J
   #87 = Utf8               (Lcom/redhat/ceylon/compiler/java/test/structure/C;Ljava/lang/String;Z)V
   #88 = Utf8               ceylon/language/process
   #89 = Utf8               getProcess
   #90 = Utf8               ()Lceylon/language/process;
   #91 = Utf8               setupArguments
   #92 = Class              #94           //  com/redhat/ceylon/compiler/java/Bsms
   #93 = NameAndType        #95:#99       //  bsm:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;)Ljava/lang/invoke/CallSite;
   #94 = Utf8               com/redhat/ceylon/compiler/java/Bsms
   #95 = Utf8               bsm
   #96 = Class              #101          //  java/lang/invoke/MethodHandles$Lookup
   #97 = Utf8               Lookup
   #98 = Utf8               InnerClasses
   #99 = Utf8               (Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;)Ljava/lang/invoke/CallSite;
  #100 = Class              #102          //  java/lang/invoke/MethodHandles
  #101 = Utf8               java/lang/invoke/MethodHandles$Lookup
  #102 = Utf8               java/lang/invoke/MethodHandles
{
  public final void m(java.lang.String);
    Signature: (Ljava/lang/String;)V
    flags: ACC_PUBLIC, ACC_FINAL
    Code:
      stack=2, locals=2, args_size=2
         0: new           #1                  // class java/lang/StringBuilder
         3: dup           
         4: invokespecial #2                  // Method java/lang/StringBuilder."<init>":()V
         7: ldc           #3                  // String Greeting: 
         9: invokevirtual #4                  // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
        12: aload_1       
        13: invokevirtual #4                  // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
        16: invokevirtual #5                  // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
        19: invokestatic  #6                  // Method ceylon/language/String.instance:(Ljava/lang/String;)Lceylon/language/String;
        22: invokestatic  #7                  // Method ceylon/language/print.print:(Ljava/lang/Object;)V
        25: return        
      LineNumberTable:
        line 4: 0

  com.redhat.ceylon.compiler.java.test.structure.C();
    Signature: ()V
    flags: 
    Code:
      stack=5, locals=5, args_size=1
         0: aload_0       
         1: invokespecial #8                  // Method java/lang/Object."<init>":()V
         4: new           #9                  // class ceylon/language/Range
         7: dup           
         8: lconst_0      
         9: invokestatic  #10                 // Method ceylon/language/Integer.instance:(J)Lceylon/language/Integer;
        12: lconst_1      
        13: invokestatic  #10                 // Method ceylon/language/Integer.instance:(J)Lceylon/language/Integer;
        16: invokespecial #11                 // Method ceylon/language/Range."<init>":(Lceylon/language/Comparable;Lceylon/language/Comparable;)V
        19: invokevirtual #12                 // Method ceylon/language/Range.getIterator:()Lceylon/language/Iterator;
        22: astore_2      
        23: aload_2       
        24: invokeinterface #13,  1           // InterfaceMethod ceylon/language/Iterator.next:()Ljava/lang/Object;
        29: dup           
        30: astore_1      
        31: instanceof    #14                 // class ceylon/language/Finished
        34: ifne          57
        37: aload_1       
        38: checkcast     #15                 // class ceylon/language/Integer
        41: invokevirtual #16                 // Method ceylon/language/Integer.longValue:()J
        44: lstore_3      
        45: aload_0       
        46: ldc           #17                 // String 
        48: iconst_1      
        49: invokedynamic #18,  0             // InvokeDynamic #0:m:(Lcom/redhat/ceylon/compiler/java/test/structure/C;Ljava/lang/String;Z)V
        54: goto          23
        57: return        
      LineNumberTable:
        line 6: 4
        line 7: 23
        line 6: 37
        line 7: 45
      StackMapTable: number_of_entries = 2
           frame_type = 255 /* full_frame */
          offset_delta = 23
          locals = [ class com/redhat/ceylon/compiler/java/test/structure/C, top, class ceylon/language/Iterator ]
          stack = []
           frame_type = 255 /* full_frame */
          offset_delta = 33
          locals = [ class com/redhat/ceylon/compiler/java/test/structure/C, class java/lang/Object ]
          stack = []


  public static void main(java.lang.String[]);
    Signature: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=1
         0: invokestatic  #19                 // Method ceylon/language/process.getProcess:()Lceylon/language/process;
         3: aload_0       
         4: invokevirtual #20                 // Method ceylon/language/process.setupArguments:([Ljava/lang/String;)V
         7: new           #21                 // class com/redhat/ceylon/compiler/java/test/structure/C
        10: dup           
        11: invokespecial #22                 // Method "<init>":()V
        14: pop           
        15: return        
}
```

The only interesting bits of that are the BootstrapMethods attribute right at the top:

```
  BootstrapMethods:
    0: #39 invokestatic com/redhat/ceylon/compiler/java/Bsms.bsm:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;)Ljava/lang/invoke/CallSite;
      Method arguments:
        #40 hello, world
```

And the invokedynamic instruction itself:

        49: invokedynamic #18,  0             // InvokeDynamic #0:m:(Lcom/redhat/ceylon/compiler/java/test/structure/C;Ljava/lang/String;Z)V

Finally, the output we get from doing a `new C()` at runtime:

```
bsm
 lookup:   com.redhat.ceylon.compiler.java.test.structure.C
 methodName:  m
 methodType:  (C,String,boolean)void
 sa1: hello, world
Greeting: hello, world
Greeting: hello, world
```

We can see the parameters passed to the BSM, followed by the return of the Ceylon-side `print()`. Of course the BSM is only called once because the JVM uses the `CallSite` it returns on first invocation to link do its linkage thing.