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added compile stub class to support reflection based interop against …
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…class being defined
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@richhickey
richhickey committed Oct 26, 2009
1 parent 2ebf995 commit 6362e0f
Showing 1 changed file with 104 additions and 13 deletions.
117 changes: 104 additions & 13 deletions src/jvm/clojure/lang/Compiler.java
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Expand Up @@ -77,6 +77,7 @@ public class Compiler implements Opcodes{

static final Keyword volatileKey = Keyword.intern(null, "volatile");
static final Keyword implementsKey = Keyword.intern(null, "implements");
static final String COMPILE_STUB_PREFIX = "compile__stub";

static final Symbol NS = Symbol.create("ns");
static final Symbol IN_NS = Symbol.create("in-ns");
Expand Down Expand Up @@ -215,6 +216,10 @@ public class Compiler implements Opcodes{
static final public Var RET_LOCAL_NUM = Var.create();


static final public Var COMPILE_STUB_SYM = Var.create(null);
static final public Var COMPILE_STUB_CLASS = Var.create(null);


public enum C{
STATEMENT, //value ignored
EXPRESSION, //value required
Expand Down Expand Up @@ -780,6 +785,8 @@ private static Class maybeClass(Object form, boolean stringOk) throws Exception{
Symbol sym = (Symbol) form;
if(sym.ns == null) //if ns-qualified can't be classname
{
if(Util.equals(sym,COMPILE_STUB_SYM.get()))
return (Class) COMPILE_STUB_CLASS.get();
if(sym.name.indexOf('.') > 0 || sym.name.charAt(0) == '[')
c = RT.classForName(sym.name);
else
Expand Down Expand Up @@ -891,8 +898,8 @@ public void emitUnboxed(C context, ObjExpr objx, GeneratorAdapter gen){
if(targetClass != null && field != null)
{
target.emit(C.EXPRESSION, objx, gen);
gen.checkCast(Type.getType(targetClass));
gen.getField(Type.getType(targetClass), fieldName, Type.getType(field.getType()));
gen.checkCast(getType(targetClass));
gen.getField(getType(targetClass), fieldName, Type.getType(field.getType()));
}
else
throw new UnsupportedOperationException("Unboxed emit of unknown member");
Expand All @@ -903,8 +910,8 @@ public void emit(C context, ObjExpr objx, GeneratorAdapter gen){
if(targetClass != null && field != null)
{
target.emit(C.EXPRESSION, objx, gen);
gen.checkCast(Type.getType(targetClass));
gen.getField(Type.getType(targetClass), fieldName, Type.getType(field.getType()));
gen.checkCast(getType(targetClass));
gen.getField(getType(targetClass), fieldName, Type.getType(field.getType()));
//if(context != C.STATEMENT)
HostExpr.emitBoxReturn(objx, gen, field.getType());
if(context == C.STATEMENT)
Expand Down Expand Up @@ -3033,7 +3040,7 @@ else throw new RuntimeException(
}
else
{
gen.push(cc.getName());
gen.push(destubClassName(cc.getName()));
gen.invokeStatic(Type.getType(Class.class), Method.getMethod("Class forName(String)"));
}
}
Expand Down Expand Up @@ -4537,6 +4544,20 @@ else if(o instanceof Symbol)

}

static String destubClassName(String className){
//skip over prefix + '.' or '/'
if(className.startsWith(COMPILE_STUB_PREFIX))
return className.substring(COMPILE_STUB_PREFIX.length()+1);
return className;
}

static Type getType(Class c){
String descriptor = Type.getType(c).getDescriptor();
if(descriptor.startsWith("L"))
descriptor = "L" + destubClassName(descriptor.substring(1));
return Type.getType(descriptor);
}

static Object resolve(Symbol sym, boolean allowPrivate) throws Exception{
return resolveIn(currentNS(), sym, allowPrivate);
}
Expand Down Expand Up @@ -4587,6 +4608,8 @@ else if(sym.equals(IN_NS))
return RT.IN_NS_VAR;
else
{
if(Util.equals(sym,COMPILE_STUB_SYM.get()))
return COMPILE_STUB_CLASS.get();
Object o = n.getMapping(sym);
if(o == null)
{
Expand Down Expand Up @@ -5061,7 +5084,15 @@ static Expr build(IPersistentVector interfaceSyms, IPersistentVector fieldSyms,
Map[] mc = gatherMethods(superClass,RT.seq(interfaces));
Map overrideables = mc[0];
Map allmethods = mc[1];
String[] inames = interfaceNames(interfaces);

Symbol thistag = null;
Class stub = null;
if(ret.isDefclass())
{
stub = compileStub(slashname(superClass),ret, inames);
thistag = Symbol.intern(null,stub.getName());
}
try
{
Var.pushThreadBindings(
Expand All @@ -5070,15 +5101,18 @@ static Expr build(IPersistentVector interfaceSyms, IPersistentVector fieldSyms,
VARS, PersistentHashMap.EMPTY));
if(ret.isDefclass())
{
Var.pushThreadBindings(RT.map(METHOD,null,LOCAL_ENV,ret.fields));
Var.pushThreadBindings(RT.map(METHOD,null,
LOCAL_ENV,ret.fields
,COMPILE_STUB_SYM, Symbol.intern(null,stub.getSimpleName())
,COMPILE_STUB_CLASS, stub));
}

//now (methodname [args] body)*
ret.line = (Integer) LINE.deref();
IPersistentCollection methods = null;
for(ISeq s = methodForms; s != null; s = RT.next(s))
{
NewInstanceMethod m = NewInstanceMethod.parse(ret, (ISeq) RT.first(s),overrideables, allmethods);
NewInstanceMethod m = NewInstanceMethod.parse(ret, (ISeq) RT.first(s),thistag, overrideables, allmethods);
methods = RT.conj(methods, m);
}

Expand All @@ -5096,15 +5130,68 @@ static Expr build(IPersistentVector interfaceSyms, IPersistentVector fieldSyms,
Var.popThreadBindings();
}

int icnt = interfaces.count();
String[] inames = icnt > 0 ? new String[icnt] : null;
for(int i=0;i<icnt;i++)
inames[i] = slashname((Class) interfaces.nth(i));
ret.compile(slashname(superClass),inames,false);
ret.getCompiledClass();
return ret;
}

/***
* Current host interop uses reflection, which requires pre-existing classes
* Work around this by:
* Generate a stub class that has the same interfaces and fields as the class we are generating.
* Use it as a type hint for this, and bind the simple name of the class to this stub (in resolve etc)
* Unmunge the name (using a magic prefix) on any code gen for classes
*/
static Class compileStub(String superName, NewInstanceExpr ret, String[] interfaceNames){
ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
ClassVisitor cv = cw;
cv.visit(V1_5, ACC_PUBLIC + ACC_SUPER, COMPILE_STUB_PREFIX + "/" + ret.internalName,
null,superName,interfaceNames);

//instance fields for closed-overs
for(ISeq s = RT.keys(ret.closes); s != null; s = s.next())
{
LocalBinding lb = (LocalBinding) s.first();
int access = ACC_PUBLIC + (ret.isVolatile(lb) ? ACC_VOLATILE : ACC_FINAL);
if(lb.getPrimitiveType() != null)
cv.visitField(access
, lb.name, Type.getType(lb.getPrimitiveType()).getDescriptor(),
null, null);
else
//todo - when closed-overs are fields, use more specific types here and in ctor and emitLocal?
cv.visitField(access
, lb.name, OBJECT_TYPE.getDescriptor(), null, null);
}

//ctor that takes closed-overs and does nothing
Method m = new Method("<init>", Type.VOID_TYPE, ret.ctorTypes());
GeneratorAdapter ctorgen = new GeneratorAdapter(ACC_PUBLIC,
m,
null,
null,
cv);
ctorgen.visitCode();
ctorgen.loadThis();
ctorgen.invokeConstructor(Type.getObjectType(superName), voidctor);
ctorgen.returnValue();
ctorgen.endMethod();

//end of class
cv.visitEnd();

byte[] bytecode = cw.toByteArray();
DynamicClassLoader loader = (DynamicClassLoader) LOADER.deref();
return loader.defineClass(COMPILE_STUB_PREFIX + "." + ret.name, bytecode);
}

static String[] interfaceNames(IPersistentVector interfaces){
int icnt = interfaces.count();
String[] inames = icnt > 0 ? new String[icnt] : null;
for(int i=0;i<icnt;i++)
inames[i] = slashname((Class) interfaces.nth(i));
return inames;
}


static String slashname(Class c){
return c.getName().replace('.', '/');
Expand Down Expand Up @@ -5194,7 +5281,8 @@ static public IPersistentVector msig(String name,Class[] paramTypes){
return RT.vector(name,RT.seq(paramTypes));
}

static NewInstanceMethod parse(ObjExpr objx, ISeq form, Map overrideables, Map allmethods) throws Exception{
static NewInstanceMethod parse(ObjExpr objx, ISeq form, Symbol thistag,
Map overrideables, Map allmethods) throws Exception{
//(methodname [args] body...)
NewInstanceMethod method = new NewInstanceMethod(objx, (ObjMethod) METHOD.deref());
Symbol name = (Symbol)RT.first(form);
Expand All @@ -5213,7 +5301,7 @@ static NewInstanceMethod parse(ObjExpr objx, ISeq form, Map overrideables, Map a

//register 'this' as local 0
registerLocal(Symbol.intern(objx.thisName != null ? objx.thisName : "obj__" + RT.nextID()),
null, null,false);
thistag, null,false);

PersistentVector argLocals = PersistentVector.EMPTY;
method.retClass = tagClass(tagOf(name));
Expand Down Expand Up @@ -5277,6 +5365,9 @@ static NewInstanceMethod parse(ObjExpr objx, ISeq form, Map overrideables, Map a
else if(findMethodsWithName(name.name,allmethods).size()>0)
throw new IllegalArgumentException("Can't override/overload method: " + name.name);
//todo
else
throw new IllegalArgumentException("Can't define method not in interfaces: " + name.name);

//else
//validate unque name+arity among additional methods

Expand Down

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