--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dmd/interpret.c	Sat Sep 01 21:43:27 2007 +0200
@@ -0,0 +1,2106 @@
+
+// Compiler implementation of the D programming language
+// Copyright (c) 1999-2007 by Digital Mars
+// All Rights Reserved
+// written by Walter Bright
+// http://www.digitalmars.com
+// License for redistribution is by either the Artistic License
+// in artistic.txt, or the GNU General Public License in gnu.txt.
+// See the included readme.txt for details.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "mem.h"
+
+#include "statement.h"
+#include "expression.h"
+#include "cond.h"
+#include "init.h"
+#include "staticassert.h"
+#include "mtype.h"
+#include "scope.h"
+#include "declaration.h"
+#include "aggregate.h"
+#include "id.h"
+
+#define LOG	0
+
+struct InterState
+{
+    InterState *caller;		// calling function's InterState
+    FuncDeclaration *fd;	// function being interpreted
+    Dsymbols vars;		// variables used in this function
+    Statement *start;		// if !=NULL, start execution at this statement
+    Statement *gotoTarget;	// target of EXP_GOTO_INTERPRET result
+
+    InterState();
+};
+
+InterState::InterState()
+{
+    memset(this, 0, sizeof(InterState));
+}
+
+Expression *interpret_aaLen(InterState *istate, Expressions *arguments);
+Expression *interpret_aaKeys(InterState *istate, Expressions *arguments);
+Expression *interpret_aaValues(InterState *istate, Expressions *arguments);
+
+/*************************************
+ * Attempt to interpret a function given the arguments.
+ * Input:
+ *	istate	state for calling function (NULL if none)
+ * Return result expression if successful, NULL if not.
+ */
+
+Expression *FuncDeclaration::interpret(InterState *istate, Expressions *arguments)
+{
+#if LOG
+    printf("FuncDeclaration::interpret() %s\n", toChars());
+    printf("cantInterpret = %d, semanticRun = %d\n", cantInterpret, semanticRun);
+#endif
+    if (global.errors)
+	return NULL;
+    if (ident == Id::aaLen)
+	return interpret_aaLen(istate, arguments);
+    else if (ident == Id::aaKeys)
+	return interpret_aaKeys(istate, arguments);
+    else if (ident == Id::aaValues)
+	return interpret_aaValues(istate, arguments);
+
+    if (cantInterpret || semanticRun == 1)
+	return NULL;
+
+    if (needThis() || isNested() || !fbody)
+    {	cantInterpret = 1;
+	return NULL;
+    }
+
+    if (semanticRun == 0 && scope)
+    {
+	semantic3(scope);
+    }
+    if (semanticRun < 2)
+	return NULL;
+
+    Type *tb = type->toBasetype();
+    assert(tb->ty == Tfunction);
+    TypeFunction *tf = (TypeFunction *)tb;
+    Type *tret = tf->next->toBasetype();
+    if (tf->varargs /*|| tret->ty == Tvoid*/)
+    {	cantInterpret = 1;
+	return NULL;
+    }
+
+    if (tf->parameters)
+    {	size_t dim = Argument::dim(tf->parameters);
+	for (size_t i = 0; i < dim; i++)
+	{   Argument *arg = Argument::getNth(tf->parameters, i);
+	    if (arg->storageClass & STClazy)
+	    {   cantInterpret = 1;
+		return NULL;
+	    }
+	}
+    }
+
+    InterState istatex;
+    istatex.caller = istate;
+    istatex.fd = this;
+
+    Expressions vsave;
+    size_t dim = 0;
+    if (arguments)
+    {
+	dim = arguments->dim;
+	assert(!dim || parameters->dim == dim);
+	vsave.setDim(dim);
+
+	for (size_t i = 0; i < dim; i++)
+	{   Expression *earg = (Expression *)arguments->data[i];
+	    Argument *arg = Argument::getNth(tf->parameters, i);
+	    VarDeclaration *v = (VarDeclaration *)parameters->data[i];
+	    vsave.data[i] = v->value;
+#if LOG
+	    printf("arg[%d] = %s\n", i, earg->toChars());
+#endif
+	    if (arg->storageClass & (STCout | STCref))
+	    {
+		/* Bind out or ref parameter to the corresponding
+		 * variable v2
+		 */
+		if (!istate || earg->op != TOKvar)
+		    return NULL;	// can't bind to non-interpreted vars
+
+		VarDeclaration *v2;
+		while (1)
+		{
+		    VarExp *ve = (VarExp *)earg;
+		    v2 = ve->var->isVarDeclaration();
+		    if (!v2)
+			return NULL;
+		    if (!v2->value || v2->value->op != TOKvar)
+			break;
+		    earg = v2->value;
+		}
+
+		v->value = new VarExp(earg->loc, v2);
+
+		/* Don't restore the value of v2 upon function return
+		 */
+		assert(istate);
+		for (size_t i = 0; i < istate->vars.dim; i++)
+		{   VarDeclaration *v = (VarDeclaration *)istate->vars.data[i];
+		    if (v == v2)
+		    {	istate->vars.data[i] = NULL;
+			break;
+		    }
+		}
+	    }
+	    else
+	    {	/* Value parameters
+		 */
+		earg = earg->interpret(&istatex);
+		if (earg == EXP_CANT_INTERPRET)
+		    return NULL;
+		v->value = earg;
+	    }
+#if LOG
+	    printf("interpreted arg[%d] = %s\n", i, earg->toChars());
+#endif
+	}
+    }
+
+    /* Save the values of the local variables used
+     */
+    Expressions valueSaves;
+    if (istate)
+    {
+	//printf("saving state...\n");
+	valueSaves.setDim(istate->vars.dim);
+	for (size_t i = 0; i < istate->vars.dim; i++)
+	{   VarDeclaration *v = (VarDeclaration *)istate->vars.data[i];
+	    if (v)
+	    {
+		//printf("\tsaving [%d] %s = %s\n", i, v->toChars(), v->value->toChars());
+		valueSaves.data[i] = v->value;
+		v->value = NULL;
+	    }
+	}
+    }
+
+    Expression *e = NULL;
+
+    while (1)
+    {
+	e = fbody->interpret(&istatex);
+	if (e == EXP_CANT_INTERPRET)
+	{
+#if LOG
+	    printf("function body failed to interpret\n");
+#endif
+	    e = NULL;
+	}
+
+	/* This is how we deal with a recursive statement AST
+	 * that has arbitrary goto statements in it.
+	 * Bubble up a 'result' which is the target of the goto
+	 * statement, then go recursively down the AST looking
+	 * for that statement, then execute starting there.
+	 */
+	if (e == EXP_GOTO_INTERPRET)
+	{
+	    istatex.start = istatex.gotoTarget;	// set starting statement
+	    istatex.gotoTarget = NULL;
+	}
+	else
+	    break;
+    }
+
+    /* Restore the parameter values
+     */
+    for (size_t i = 0; i < dim; i++)
+    {
+	VarDeclaration *v = (VarDeclaration *)parameters->data[i];
+	v->value = (Expression *)vsave.data[i];
+    }
+
+    if (istate)
+    {
+	/* Restore the variable values
+	 */
+	for (size_t i = 0; i < istate->vars.dim; i++)
+	{   VarDeclaration *v = (VarDeclaration *)istate->vars.data[i];
+	    if (v)
+		v->value = (Expression *)valueSaves.data[i];
+	}
+    }
+
+    return e;
+}
+
+/******************************** Statement ***************************/
+
+#define START()				\
+    if (istate->start)			\
+    {	if (istate->start != this)	\
+	    return NULL;		\
+	istate->start = NULL;		\
+    }
+
+/***********************************
+ * Interpret the statement.
+ * Returns:
+ *	NULL	continue to next statement
+ *	EXP_CANT_INTERPRET	cannot interpret statement at compile time
+ *	!NULL	expression from return statement
+ */
+
+Expression *Statement::interpret(InterState *istate)
+{
+#if LOG
+    printf("Statement::interpret()\n");
+#endif
+    START()
+    return EXP_CANT_INTERPRET;
+}
+
+Expression *ExpStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("ExpStatement::interpret(%s)\n", exp ? exp->toChars() : "");
+#endif
+    START()
+    if (exp)
+    {
+	Expression *e = exp->interpret(istate);
+	if (e == EXP_CANT_INTERPRET)
+	{
+	    //printf("cannot interpret %s\n", exp->toChars());
+	    return EXP_CANT_INTERPRET;
+	}
+    }
+    return NULL;
+}
+
+Expression *CompoundStatement::interpret(InterState *istate)
+{   Expression *e = NULL;
+
+#if LOG
+    printf("CompoundStatement::interpret()\n");
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    if (statements)
+    {
+	for (size_t i = 0; i < statements->dim; i++)
+	{   Statement *s = (Statement *)statements->data[i];
+
+	    if (s)
+	    {
+		e = s->interpret(istate);
+		if (e)
+		    break;
+	    }
+	}
+    }
+#if LOG
+    printf("-CompoundStatement::interpret() %p\n", e);
+#endif
+    return e;
+}
+
+Expression *UnrolledLoopStatement::interpret(InterState *istate)
+{   Expression *e = NULL;
+
+#if LOG
+    printf("UnrolledLoopStatement::interpret()\n");
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    if (statements)
+    {
+	for (size_t i = 0; i < statements->dim; i++)
+	{   Statement *s = (Statement *)statements->data[i];
+
+	    e = s->interpret(istate);
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    if (e == EXP_CONTINUE_INTERPRET)
+	    {	e = NULL;
+		continue;
+	    }
+	    if (e == EXP_BREAK_INTERPRET)
+	    {	e = NULL;
+		break;
+	    }
+	    if (e)
+		break;
+	}
+    }
+    return e;
+}
+
+Expression *IfStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("IfStatement::interpret(%s)\n", condition->toChars());
+#endif
+
+    if (istate->start == this)
+	istate->start = NULL;
+    if (istate->start)
+    {
+	Expression *e = NULL;
+	if (ifbody)
+	    e = ifbody->interpret(istate);
+	if (istate->start && elsebody)
+	    e = elsebody->interpret(istate);
+	return e;
+    }
+
+    Expression *e = condition->interpret(istate);
+    assert(e);
+    //if (e == EXP_CANT_INTERPRET) printf("cannot interpret\n");
+    if (e != EXP_CANT_INTERPRET)
+    {
+	if (!e->isConst())
+	{
+	    e = EXP_CANT_INTERPRET;
+	}
+	else
+	{
+	    if (e->isBool(TRUE))
+		e = ifbody ? ifbody->interpret(istate) : NULL;
+	    else if (e->isBool(FALSE))
+		e = elsebody ? elsebody->interpret(istate) : NULL;
+	    else
+	    {
+		e = EXP_CANT_INTERPRET;
+	    }
+	}
+    }
+    return e;
+}
+
+Expression *ScopeStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("ScopeStatement::interpret()\n");
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    return statement ? statement->interpret(istate) : NULL;
+}
+
+Expression *ReturnStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("ReturnStatement::interpret(%s)\n", exp ? exp->toChars() : "");
+#endif
+    START()
+    if (!exp)
+	return EXP_VOID_INTERPRET;
+#if LOG
+    Expression *e = exp->interpret(istate);
+    printf("e = %p\n", e);
+    return e;
+#else
+    return exp->interpret(istate);
+#endif
+}
+
+Expression *BreakStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("BreakStatement::interpret()\n");
+#endif
+    START()
+    if (ident)
+	return EXP_CANT_INTERPRET;
+    else
+	return EXP_BREAK_INTERPRET;
+}
+
+Expression *ContinueStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("ContinueStatement::interpret()\n");
+#endif
+    START()
+    if (ident)
+	return EXP_CANT_INTERPRET;
+    else
+	return EXP_CONTINUE_INTERPRET;
+}
+
+Expression *WhileStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("WhileStatement::interpret()\n");
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    Expression *e;
+
+    if (istate->start)
+    {
+	e = body ? body->interpret(istate) : NULL;
+	if (istate->start)
+	    return NULL;
+	if (e == EXP_CANT_INTERPRET)
+	    return e;
+	if (e == EXP_BREAK_INTERPRET)
+	    return NULL;
+	if (e != EXP_CONTINUE_INTERPRET)
+	    return e;
+    }
+
+    while (1)
+    {
+	e = condition->interpret(istate);
+	if (e == EXP_CANT_INTERPRET)
+	    break;
+	if (!e->isConst())
+	{   e = EXP_CANT_INTERPRET;
+	    break;
+	}
+	if (e->isBool(TRUE))
+	{   e = body ? body->interpret(istate) : NULL;
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    if (e == EXP_CONTINUE_INTERPRET)
+		continue;
+	    if (e == EXP_BREAK_INTERPRET)
+	    {	e = NULL;
+		break;
+	    }
+	    if (e)
+		break;
+	}
+	else if (e->isBool(FALSE))
+	{   e = NULL;
+	    break;
+	}
+	else
+	    assert(0);
+    }
+    return e;
+}
+
+Expression *DoStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("DoStatement::interpret()\n");
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    Expression *e;
+
+    if (istate->start)
+    {
+	e = body ? body->interpret(istate) : NULL;
+	if (istate->start)
+	    return NULL;
+	if (e == EXP_CANT_INTERPRET)
+	    return e;
+	if (e == EXP_BREAK_INTERPRET)
+	    return NULL;
+	if (e == EXP_CONTINUE_INTERPRET)
+	    goto Lcontinue;
+	if (e)
+	    return e;
+    }
+
+    while (1)
+    {
+	e = body ? body->interpret(istate) : NULL;
+	if (e == EXP_CANT_INTERPRET)
+	    break;
+	if (e == EXP_BREAK_INTERPRET)
+	{   e = NULL;
+	    break;
+	}
+	if (e && e != EXP_CONTINUE_INTERPRET)
+	    break;
+
+    Lcontinue:
+	e = condition->interpret(istate);
+	if (e == EXP_CANT_INTERPRET)
+	    break;
+	if (!e->isConst())
+	{   e = EXP_CANT_INTERPRET;
+	    break;
+	}
+	if (e->isBool(TRUE))
+	{
+	}
+	else if (e->isBool(FALSE))
+	{   e = NULL;
+	    break;
+	}
+	else
+	    assert(0);
+    }
+    return e;
+}
+
+Expression *ForStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("ForStatement::interpret()\n");
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    Expression *e;
+
+    if (init)
+    {
+	e = init->interpret(istate);
+	if (e == EXP_CANT_INTERPRET)
+	    return e;
+	assert(!e);
+    }
+
+    if (istate->start)
+    {
+	e = body ? body->interpret(istate) : NULL;
+	if (istate->start)
+	    return NULL;
+	if (e == EXP_CANT_INTERPRET)
+	    return e;
+	if (e == EXP_BREAK_INTERPRET)
+	    return NULL;
+	if (e == EXP_CONTINUE_INTERPRET)
+	    goto Lcontinue;
+	if (e)
+	    return e;
+    }
+
+    while (1)
+    {
+	e = condition->interpret(istate);
+	if (e == EXP_CANT_INTERPRET)
+	    break;
+	if (!e->isConst())
+	{   e = EXP_CANT_INTERPRET;
+	    break;
+	}
+	if (e->isBool(TRUE))
+	{   e = body ? body->interpret(istate) : NULL;
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    if (e == EXP_BREAK_INTERPRET)
+	    {   e = NULL;
+		break;
+	    }
+	    if (e && e != EXP_CONTINUE_INTERPRET)
+		break;
+	Lcontinue:
+	    e = increment->interpret(istate);
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	}
+	else if (e->isBool(FALSE))
+	{   e = NULL;
+	    break;
+	}
+	else
+	    assert(0);
+    }
+    return e;
+}
+
+Expression *ForeachStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("ForeachStatement::interpret()\n");
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    if (istate->start)
+	return NULL;
+
+    Expression *e = NULL;
+    Expression *eaggr;
+
+    if (value->isOut() || value->isRef())
+	return EXP_CANT_INTERPRET;
+
+    eaggr = aggr->interpret(istate);
+    if (eaggr == EXP_CANT_INTERPRET)
+	return EXP_CANT_INTERPRET;
+
+    Expression *dim = ArrayLength(Type::tsize_t, eaggr);
+    if (dim == EXP_CANT_INTERPRET)
+	return EXP_CANT_INTERPRET;
+
+    Expression *keysave = key ? key->value : NULL;
+    Expression *valuesave = value->value;
+
+    uinteger_t d = dim->toUInteger();
+    uinteger_t index;
+
+    if (op == TOKforeach)
+    {
+	for (index = 0; index < d; index++)
+	{
+	    Expression *ekey = new IntegerExp(loc, index, Type::tsize_t);
+	    if (key)
+		key->value = ekey;
+	    e = Index(value->type, eaggr, ekey);
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    value->value = e;
+
+	    e = body ? body->interpret(istate) : NULL;
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    if (e == EXP_BREAK_INTERPRET)
+	    {   e = NULL;
+		break;
+	    }
+	    if (e == EXP_CONTINUE_INTERPRET)
+		e = NULL;
+	    else if (e)
+		break;
+	}
+    }
+    else // TOKforeach_reverse
+    {
+	for (index = d; index-- != 0;)
+	{
+	    Expression *ekey = new IntegerExp(loc, index, Type::tsize_t);
+	    if (key)
+		key->value = ekey;
+	    e = Index(value->type, eaggr, ekey);
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    value->value = e;
+
+	    e = body ? body->interpret(istate) : NULL;
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    if (e == EXP_BREAK_INTERPRET)
+	    {   e = NULL;
+		break;
+	    }
+	    if (e == EXP_CONTINUE_INTERPRET)
+		e = NULL;
+	    else if (e)
+		break;
+	}
+    }
+    value->value = valuesave;
+    if (key)
+	key->value = keysave;
+    return e;
+}
+
+#if V2
+Expression *ForeachRangeStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("ForeachRangeStatement::interpret()\n");
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    if (istate->start)
+	return NULL;
+
+    Expression *e = NULL;
+    Expression *elwr = lwr->interpret(istate);
+    if (elwr == EXP_CANT_INTERPRET)
+	return EXP_CANT_INTERPRET;
+
+    Expression *eupr = upr->interpret(istate);
+    if (eupr == EXP_CANT_INTERPRET)
+	return EXP_CANT_INTERPRET;
+
+    Expression *keysave = key->value;
+
+    if (op == TOKforeach)
+    {
+	key->value = elwr;
+
+	while (1)
+	{
+	    e = Cmp(TOKlt, key->value->type, key->value, upr);
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    if (e->isBool(TRUE) == FALSE)
+	    {	e = NULL;
+		break;
+	    }
+
+	    e = body ? body->interpret(istate) : NULL;
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    if (e == EXP_BREAK_INTERPRET)
+	    {   e = NULL;
+		break;
+	    }
+	    e = Add(key->value->type, key->value, new IntegerExp(loc, 1, key->value->type));
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    key->value = e;
+	}
+    }
+    else // TOKforeach_reverse
+    {
+	key->value = eupr;
+
+	while (1)
+	{
+	    e = Cmp(TOKgt, key->value->type, key->value, lwr);
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    if (e->isBool(TRUE) == FALSE)
+	    {	e = NULL;
+		break;
+	    }
+
+	    e = Min(key->value->type, key->value, new IntegerExp(loc, 1, key->value->type));
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    key->value = e;
+
+	    e = body ? body->interpret(istate) : NULL;
+	    if (e == EXP_CANT_INTERPRET)
+		break;
+	    if (e == EXP_BREAK_INTERPRET)
+	    {   e = NULL;
+		break;
+	    }
+	}
+    }
+    key->value = keysave;
+    return e;
+}
+#endif
+
+Expression *SwitchStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("SwitchStatement::interpret()\n");
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    Expression *e = NULL;
+
+    if (istate->start)
+    {
+	e = body ? body->interpret(istate) : NULL;
+	if (istate->start)
+	    return NULL;
+	if (e == EXP_CANT_INTERPRET)
+	    return e;
+	if (e == EXP_BREAK_INTERPRET)
+	    return NULL;
+	return e;
+    }
+
+
+    Expression *econdition = condition->interpret(istate);
+    if (econdition == EXP_CANT_INTERPRET)
+	return EXP_CANT_INTERPRET;
+
+    Statement *s = NULL;
+    if (cases)
+    {
+	for (size_t i = 0; i < cases->dim; i++)
+	{
+	    CaseStatement *cs = (CaseStatement *)cases->data[i];
+	    e = Equal(TOKequal, Type::tint32, econdition, cs->exp);
+	    if (e == EXP_CANT_INTERPRET)
+		return EXP_CANT_INTERPRET;
+	    if (e->isBool(TRUE))
+	    {	s = cs;
+		break;
+	    }
+	}
+    }
+    if (!s)
+    {	if (hasNoDefault)
+	    error("no default or case for %s in switch statement", econdition->toChars());
+	s = sdefault;
+    }
+
+    assert(s);
+    istate->start = s;
+    e = body ? body->interpret(istate) : NULL;
+    assert(!istate->start);
+    if (e == EXP_BREAK_INTERPRET)
+	return NULL;
+    return e;
+}
+
+Expression *CaseStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("CaseStatement::interpret(%s) this = %p\n", exp->toChars(), this);
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    if (statement)
+	return statement->interpret(istate);
+    else
+	return NULL;
+}
+
+Expression *DefaultStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("DefaultStatement::interpret()\n");
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    if (statement)
+	return statement->interpret(istate);
+    else
+	return NULL;
+}
+
+Expression *GotoStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("GotoStatement::interpret()\n");
+#endif
+    START()
+    assert(label && label->statement);
+    istate->gotoTarget = label->statement;
+    return EXP_GOTO_INTERPRET;
+}
+
+Expression *GotoCaseStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("GotoCaseStatement::interpret()\n");
+#endif
+    START()
+    assert(cs);
+    istate->gotoTarget = cs;
+    return EXP_GOTO_INTERPRET;
+}
+
+Expression *GotoDefaultStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("GotoDefaultStatement::interpret()\n");
+#endif
+    START()
+    assert(sw && sw->sdefault);
+    istate->gotoTarget = sw->sdefault;
+    return EXP_GOTO_INTERPRET;
+}
+
+Expression *LabelStatement::interpret(InterState *istate)
+{
+#if LOG
+    printf("LabelStatement::interpret()\n");
+#endif
+    if (istate->start == this)
+	istate->start = NULL;
+    return statement ? statement->interpret(istate) : NULL;
+}
+
+/******************************** Expression ***************************/
+
+Expression *Expression::interpret(InterState *istate)
+{
+#if LOG
+    printf("Expression::interpret() %s\n", toChars());
+#endif
+    return EXP_CANT_INTERPRET;
+}
+
+Expression *NullExp::interpret(InterState *istate)
+{
+    return this;
+}
+
+Expression *IntegerExp::interpret(InterState *istate)
+{
+#if LOG
+    printf("IntegerExp::interpret() %s\n", toChars());
+#endif
+    return this;
+}
+
+Expression *RealExp::interpret(InterState *istate)
+{
+#if LOG
+    printf("RealExp::interpret() %s\n", toChars());
+#endif
+    return this;
+}
+
+Expression *ComplexExp::interpret(InterState *istate)
+{
+    return this;
+}
+
+Expression *StringExp::interpret(InterState *istate)
+{
+#if LOG
+    printf("StringExp::interpret() %s\n", toChars());
+#endif
+    return this;
+}
+
+Expression *getVarExp(Loc loc, InterState *istate, Declaration *d)
+{
+    Expression *e = EXP_CANT_INTERPRET;
+    VarDeclaration *v = d->isVarDeclaration();
+    SymbolDeclaration *s = d->isSymbolDeclaration();
+    if (v)
+    {
+	if (v->isConst() && v->init)
+	{   e = v->init->toExpression();
+	    if (!e->type)
+		e->type = v->type;
+	}
+	else
+	{   e = v->value;
+	    if (!e)
+		error(loc, "variable %s is used before initialization", v->toChars());
+	    else if (e != EXP_CANT_INTERPRET)
+		e = e->interpret(istate);
+	}
+	if (!e)
+	    e = EXP_CANT_INTERPRET;
+    }
+    else if (s)
+    {
+	if (s->dsym->toInitializer() == s->sym)
+	{   Expressions *exps = new Expressions();
+	    e = new StructLiteralExp(0, s->dsym, exps);
+	    e = e->semantic(NULL);
+	}
+    }
+    return e;
+}
+
+Expression *VarExp::interpret(InterState *istate)
+{
+#if LOG
+    printf("VarExp::interpret() %s\n", toChars());
+#endif
+    return getVarExp(loc, istate, var);
+}
+
+Expression *DeclarationExp::interpret(InterState *istate)
+{
+#if LOG
+    printf("DeclarationExp::interpret() %s\n", toChars());
+#endif
+    Expression *e = EXP_CANT_INTERPRET;
+    VarDeclaration *v = declaration->isVarDeclaration();
+    if (v)
+    {
+	Dsymbol *s = v->toAlias();
+	if (s == v && !v->isStatic() && v->init)
+	{
+	    ExpInitializer *ie = v->init->isExpInitializer();
+	    if (ie)
+		e = ie->exp->interpret(istate);
+	    else if (v->init->isVoidInitializer())
+		e = NULL;
+	}
+	else if (s == v && v->isConst() && v->init)
+	{   e = v->init->toExpression();
+	    if (!e)
+		e = EXP_CANT_INTERPRET;
+	    else if (!e->type)
+		e->type = v->type;
+	}
+    }
+    return e;
+}
+
+Expression *TupleExp::interpret(InterState *istate)
+{
+#if LOG
+    printf("TupleExp::interpret() %s\n", toChars());
+#endif
+    Expressions *expsx = NULL;
+
+    for (size_t i = 0; i < exps->dim; i++)
+    {   Expression *e = (Expression *)exps->data[i];
+	Expression *ex;
+
+	ex = e->interpret(istate);
+	if (ex == EXP_CANT_INTERPRET)
+	{   delete expsx;
+	    return ex;
+	}
+
+	/* If any changes, do Copy On Write
+	 */
+	if (ex != e)
+	{
+	    if (!expsx)
+	    {	expsx = new Expressions();
+		expsx->setDim(exps->dim);
+		for (size_t j = 0; j < i; j++)
+		{
+		    expsx->data[j] = exps->data[j];
+		}
+	    }
+	    expsx->data[i] = (void *)ex;
+	}
+    }
+    if (expsx)
+    {	TupleExp *te = new TupleExp(loc, expsx);
+	expandTuples(te->exps);
+	te->type = new TypeTuple(te->exps);
+	return te;
+    }
+    return this;
+}
+
+Expression *ArrayLiteralExp::interpret(InterState *istate)
+{   Expressions *expsx = NULL;
+
+#if LOG
+    printf("ArrayLiteralExp::interpret() %s\n", toChars());
+#endif
+    if (elements)
+    {
+	for (size_t i = 0; i < elements->dim; i++)
+	{   Expression *e = (Expression *)elements->data[i];
+	    Expression *ex;
+
+	    ex = e->interpret(istate);
+	    if (ex == EXP_CANT_INTERPRET)
+	    {   delete expsx;
+		return EXP_CANT_INTERPRET;
+	    }
+
+	    /* If any changes, do Copy On Write
+	     */
+	    if (ex != e)
+	    {
+		if (!expsx)
+		{   expsx = new Expressions();
+		    expsx->setDim(elements->dim);
+		    for (size_t j = 0; j < i; j++)
+		    {
+			expsx->data[j] = elements->data[j];
+		    }
+		}
+		expsx->data[i] = (void *)ex;
+	    }
+	}
+    }
+    if (elements && expsx)
+    {
+	expandTuples(expsx);
+	if (expsx->dim != elements->dim)
+	{   delete expsx;
+	    return EXP_CANT_INTERPRET;
+	}
+	ArrayLiteralExp *ae = new ArrayLiteralExp(loc, expsx);
+	ae->type = type;
+	return ae;
+    }
+    return this;
+}
+
+Expression *AssocArrayLiteralExp::interpret(InterState *istate)
+{   Expressions *keysx = keys;
+    Expressions *valuesx = values;
+
+#if LOG
+    printf("AssocArrayLiteralExp::interpret() %s\n", toChars());
+#endif
+    for (size_t i = 0; i < keys->dim; i++)
+    {   Expression *ekey = (Expression *)keys->data[i];
+	Expression *evalue = (Expression *)values->data[i];
+	Expression *ex;
+
+	ex = ekey->interpret(istate);
+	if (ex == EXP_CANT_INTERPRET)
+	    goto Lerr;
+
+	/* If any changes, do Copy On Write
+	 */
+	if (ex != ekey)
+	{
+	    if (keysx == keys)
+		keysx = (Expressions *)keys->copy();
+	    keysx->data[i] = (void *)ex;
+	}
+
+	ex = evalue->interpret(istate);
+	if (ex == EXP_CANT_INTERPRET)
+	    goto Lerr;
+
+	/* If any changes, do Copy On Write
+	 */
+	if (ex != evalue)
+	{
+	    if (valuesx == values)
+		valuesx = (Expressions *)values->copy();
+	    valuesx->data[i] = (void *)ex;
+	}
+    }
+    if (keysx != keys)
+	expandTuples(keysx);
+    if (valuesx != values)
+	expandTuples(valuesx);
+    if (keysx->dim != valuesx->dim)
+	goto Lerr;
+
+    /* Remove duplicate keys
+     */
+    for (size_t i = 1; i < keysx->dim; i++)
+    {   Expression *ekey = (Expression *)keysx->data[i - 1];
+
+	for (size_t j = i; j < keysx->dim; j++)
+	{   Expression *ekey2 = (Expression *)keysx->data[j];
+	    Expression *ex = Equal(TOKequal, Type::tbool, ekey, ekey2);
+	    if (ex == EXP_CANT_INTERPRET)
+		goto Lerr;
+	    if (ex->isBool(TRUE))	// if a match
+	    {
+		// Remove ekey
+		if (keysx == keys)
+		    keysx = (Expressions *)keys->copy();
+		if (valuesx == values)
+		    valuesx = (Expressions *)values->copy();
+		keysx->remove(i - 1);
+		valuesx->remove(i - 1);
+		i -= 1;		// redo the i'th iteration
+		break;
+	    }
+	}
+    }
+
+    if (keysx != keys || valuesx != values)
+    {
+	AssocArrayLiteralExp *ae;
+	ae = new AssocArrayLiteralExp(loc, keysx, valuesx);
+	ae->type = type;
+	return ae;
+    }
+    return this;
+
+Lerr:
+    if (keysx != keys)
+	delete keysx;
+    if (valuesx != values)
+	delete values;
+    return EXP_CANT_INTERPRET;
+}
+
+Expression *StructLiteralExp::interpret(InterState *istate)
+{   Expressions *expsx = NULL;
+
+#if LOG
+    printf("StructLiteralExp::interpret() %s\n", toChars());
+#endif
+    /* We don't know how to deal with overlapping fields
+     */
+    if (sd->hasUnions)
+	return EXP_CANT_INTERPRET;
+
+    if (elements)
+    {
+	for (size_t i = 0; i < elements->dim; i++)
+	{   Expression *e = (Expression *)elements->data[i];
+	    if (!e)
+		continue;
+
+	    Expression *ex = e->interpret(istate);
+	    if (ex == EXP_CANT_INTERPRET)
+	    {   delete expsx;
+		return EXP_CANT_INTERPRET;
+	    }
+
+	    /* If any changes, do Copy On Write
+	     */
+	    if (ex != e)
+	    {
+		if (!expsx)
+		{   expsx = new Expressions();
+		    expsx->setDim(elements->dim);
+		    for (size_t j = 0; j < elements->dim; j++)
+		    {
+			expsx->data[j] = elements->data[j];
+		    }
+		}
+		expsx->data[i] = (void *)ex;
+	    }
+	}
+    }
+    if (elements && expsx)
+    {
+	expandTuples(expsx);
+	if (expsx->dim != elements->dim)
+	{   delete expsx;
+	    return EXP_CANT_INTERPRET;
+	}
+	StructLiteralExp *se = new StructLiteralExp(loc, sd, expsx);
+	se->type = type;
+	return se;
+    }
+    return this;
+}
+
+Expression *UnaExp::interpretCommon(InterState *istate, Expression *(*fp)(Type *, Expression *))
+{   Expression *e;
+    Expression *e1;
+
+#if LOG
+    printf("UnaExp::interpretCommon() %s\n", toChars());
+#endif
+    e1 = this->e1->interpret(istate);
+    if (e1 == EXP_CANT_INTERPRET)
+	goto Lcant;
+    if (e1->isConst() != 1)
+	goto Lcant;
+
+    e = (*fp)(type, e1);
+    return e;
+
+Lcant:
+    return EXP_CANT_INTERPRET;
+}
+
+#define UNA_INTERPRET(op) \
+Expression *op##Exp::interpret(InterState *istate)	\
+{							\
+    return interpretCommon(istate, &op);		\
+}
+
+UNA_INTERPRET(Neg)
+UNA_INTERPRET(Com)
+UNA_INTERPRET(Not)
+UNA_INTERPRET(Bool)
+
+
+typedef Expression *(*fp_t)(Type *, Expression *, Expression *);
+
+Expression *BinExp::interpretCommon(InterState *istate, fp_t fp)
+{   Expression *e;
+    Expression *e1;
+    Expression *e2;
+
+#if LOG
+    printf("BinExp::interpretCommon() %s\n", toChars());
+#endif
+    e1 = this->e1->interpret(istate);
+    if (e1 == EXP_CANT_INTERPRET)
+	goto Lcant;
+    if (e1->isConst() != 1)
+	goto Lcant;
+
+    e2 = this->e2->interpret(istate);
+    if (e2 == EXP_CANT_INTERPRET)
+	goto Lcant;
+    if (e2->isConst() != 1)
+	goto Lcant;
+
+    e = (*fp)(type, e1, e2);
+    return e;
+
+Lcant:
+    return EXP_CANT_INTERPRET;
+}
+
+#define BIN_INTERPRET(op) \
+Expression *op##Exp::interpret(InterState *istate)	\
+{							\
+    return interpretCommon(istate, &op);		\
+}
+
+BIN_INTERPRET(Add)
+BIN_INTERPRET(Min)
+BIN_INTERPRET(Mul)
+BIN_INTERPRET(Div)
+BIN_INTERPRET(Mod)
+BIN_INTERPRET(Shl)
+BIN_INTERPRET(Shr)
+BIN_INTERPRET(Ushr)
+BIN_INTERPRET(And)
+BIN_INTERPRET(Or)
+BIN_INTERPRET(Xor)
+
+
+typedef Expression *(*fp2_t)(enum TOK, Type *, Expression *, Expression *);
+
+Expression *BinExp::interpretCommon2(InterState *istate, fp2_t fp)
+{   Expression *e;
+    Expression *e1;
+    Expression *e2;
+
+#if LOG
+    printf("BinExp::interpretCommon2() %s\n", toChars());
+#endif
+    e1 = this->e1->interpret(istate);
+    if (e1 == EXP_CANT_INTERPRET)
+	goto Lcant;
+    if (e1->isConst() != 1 &&
+	e1->op != TOKstring &&
+	e1->op != TOKarrayliteral &&
+	e1->op != TOKstructliteral)
+	goto Lcant;
+
+    e2 = this->e2->interpret(istate);
+    if (e2 == EXP_CANT_INTERPRET)
+	goto Lcant;
+    if (e2->isConst() != 1 &&
+	e2->op != TOKstring &&
+	e2->op != TOKarrayliteral &&
+	e2->op != TOKstructliteral)
+	goto Lcant;
+
+    e = (*fp)(op, type, e1, e2);
+    return e;
+
+Lcant:
+    return EXP_CANT_INTERPRET;
+}
+
+#define BIN_INTERPRET2(op) \
+Expression *op##Exp::interpret(InterState *istate)	\
+{							\
+    return interpretCommon2(istate, &op);		\
+}
+
+BIN_INTERPRET2(Equal)
+BIN_INTERPRET2(Identity)
+BIN_INTERPRET2(Cmp)
+
+Expression *BinExp::interpretAssignCommon(InterState *istate, fp_t fp, int post)
+{
+#if LOG
+    printf("BinExp::interpretAssignCommon() %s\n", toChars());
+#endif
+    Expression *e = EXP_CANT_INTERPRET;
+    Expression *e1 = this->e1;
+
+    if (fp)
+    {
+	if (e1->op == TOKcast)
+	{   CastExp *ce = (CastExp *)e1;
+	    e1 = ce->e1;
+	}
+    }
+    if (e1 == EXP_CANT_INTERPRET)
+	return e1;
+    Expression *e2 = this->e2->interpret(istate);
+    if (e2 == EXP_CANT_INTERPRET)
+	return e2;
+
+    /* Assignment to variable of the form:
+     *	v = e2
+     */
+    if (e1->op == TOKvar)
+    {
+	VarExp *ve = (VarExp *)e1;
+	VarDeclaration *v = ve->var->isVarDeclaration();
+	if (v && !v->isDataseg())
+	{
+	    /* Chase down rebinding of out and ref
+	     */
+	    if (v->value && v->value->op == TOKvar)
+	    {
+		ve = (VarExp *)v->value;
+		v = ve->var->isVarDeclaration();
+		assert(v);
+	    }
+
+	    Expression *ev = v->value;
+	    if (fp && !ev)
+	    {	error("variable %s is used before initialization", v->toChars());
+		return e;
+	    }
+	    if (fp)
+		e2 = (*fp)(v->type, ev, e2);
+	    else
+		e2 = Cast(v->type, v->type, e2);
+	    if (e2 != EXP_CANT_INTERPRET)
+	    {
+		if (!v->isParameter())
+		{
+		    for (size_t i = 0; 1; i++)
+		    {
+			if (i == istate->vars.dim)
+			{   istate->vars.push(v);
+			    break;
+			}
+			if (v == (VarDeclaration *)istate->vars.data[i])
+			    break;
+		    }
+		}
+		v->value = e2;
+		e = Cast(type, type, post ? ev : e2);
+	    }
+	}
+    }
+    /* Assignment to struct member of the form:
+     *   *(symoffexp) = e2
+     */
+    else if (e1->op == TOKstar && ((PtrExp *)e1)->e1->op == TOKsymoff)
+    {	SymOffExp *soe = (SymOffExp *)((PtrExp *)e1)->e1;
+	VarDeclaration *v = soe->var->isVarDeclaration();
+
+	if (v->isDataseg())
+	    return EXP_CANT_INTERPRET;
+	if (fp && !v->value)
+	{   error("variable %s is used before initialization", v->toChars());
+	    return e;
+	}
+	if (v->value->op != TOKstructliteral)
+	    return EXP_CANT_INTERPRET;
+	StructLiteralExp *se = (StructLiteralExp *)v->value;
+	int fieldi = se->getFieldIndex(type, soe->offset);
+	if (fieldi == -1)
+	    return EXP_CANT_INTERPRET;
+	Expression *ev = se->getField(type, soe->offset);
+	if (fp)
+	    e2 = (*fp)(type, ev, e2);
+	else
+	    e2 = Cast(type, type, e2);
+	if (e2 == EXP_CANT_INTERPRET)
+	    return e2;
+
+	if (!v->isParameter())
+	{
+	    for (size_t i = 0; 1; i++)
+	    {
+		if (i == istate->vars.dim)
+		{   istate->vars.push(v);
+		    break;
+		}
+		if (v == (VarDeclaration *)istate->vars.data[i])
+		    break;
+	    }
+	}
+
+	/* Create new struct literal reflecting updated fieldi
+	 */
+	Expressions *expsx = new Expressions();
+	expsx->setDim(se->elements->dim);
+	for (size_t j = 0; j < expsx->dim; j++)
+	{
+	    if (j == fieldi)
+		expsx->data[j] = (void *)e2;
+	    else
+		expsx->data[j] = se->elements->data[j];
+	}
+	v->value = new StructLiteralExp(se->loc, se->sd, expsx);
+	v->value->type = se->type;
+
+	e = Cast(type, type, post ? ev : e2);
+    }
+    /* Assignment to array element of the form:
+     *   a[i] = e2
+     */
+    else if (e1->op == TOKindex && ((IndexExp *)e1)->e1->op == TOKvar)
+    {	IndexExp *ie = (IndexExp *)e1;
+	VarExp *ve = (VarExp *)ie->e1;
+	VarDeclaration *v = ve->var->isVarDeclaration();
+
+	if (!v || v->isDataseg())
+	    return EXP_CANT_INTERPRET;
+	if (!v->value)
+	{
+	    if (fp)
+	    {   error("variable %s is used before initialization", v->toChars());
+		return e;
+	    }
+
+	    Type *t = v->type->toBasetype();
+	    if (t->ty == Tsarray)
+	    {
+		/* This array was void initialized. Create a
+		 * default initializer for it.
+		 * What we should do is fill the array literal with
+		 * NULL data, so use-before-initialized can be detected.
+		 * But we're too lazy at the moment to do it, as that
+		 * involves redoing Index() and whoever calls it.
+		 */
+		Expression *ev = v->type->defaultInit();
+		size_t dim = ((TypeSArray *)t)->dim->toInteger();
+		Expressions *elements = new Expressions();
+		elements->setDim(dim);
+		for (size_t i = 0; i < dim; i++)
+		    elements->data[i] = (void *)ev;
+		ArrayLiteralExp *ae = new ArrayLiteralExp(0, elements);
+		ae->type = v->type;
+		v->value = ae;
+	    }
+	    else
+		return EXP_CANT_INTERPRET;
+	}
+
+	ArrayLiteralExp *ae = NULL;
+	AssocArrayLiteralExp *aae = NULL;
+	StringExp *se = NULL;
+	if (v->value->op == TOKarrayliteral)
+	    ae = (ArrayLiteralExp *)v->value;
+	else if (v->value->op == TOKassocarrayliteral)
+	    aae = (AssocArrayLiteralExp *)v->value;
+	else if (v->value->op == TOKstring)
+	    se = (StringExp *)v->value;
+	else
+	    return EXP_CANT_INTERPRET;
+
+	Expression *index = ie->e2->interpret(istate);
+	if (index == EXP_CANT_INTERPRET)
+	    return EXP_CANT_INTERPRET;
+	Expression *ev;
+	if (fp || ae || se)	// not for aae, because key might not be there
+	{
+	    ev = Index(type, v->value, index);
+	    if (ev == EXP_CANT_INTERPRET)
+		return EXP_CANT_INTERPRET;
+	}
+
+	if (fp)
+	    e2 = (*fp)(type, ev, e2);
+	else
+	    e2 = Cast(type, type, e2);
+	if (e2 == EXP_CANT_INTERPRET)
+	    return e2;
+
+	if (!v->isParameter())
+	{
+	    for (size_t i = 0; 1; i++)
+	    {
+		if (i == istate->vars.dim)
+		{   istate->vars.push(v);
+		    break;
+		}
+		if (v == (VarDeclaration *)istate->vars.data[i])
+		    break;
+	    }
+	}
+
+	if (ae)
+	{
+	    /* Create new array literal reflecting updated elem
+	     */
+	    int elemi = index->toInteger();
+	    Expressions *expsx = new Expressions();
+	    expsx->setDim(ae->elements->dim);
+	    for (size_t j = 0; j < expsx->dim; j++)
+	    {
+		if (j == elemi)
+		    expsx->data[j] = (void *)e2;
+		else
+		    expsx->data[j] = ae->elements->data[j];
+	    }
+	    v->value = new ArrayLiteralExp(ae->loc, expsx);
+	    v->value->type = ae->type;
+	}
+	else if (aae)
+	{
+	    /* Create new associative array literal reflecting updated key/value
+	     */
+	    Expressions *keysx = aae->keys;
+	    Expressions *valuesx = new Expressions();
+	    valuesx->setDim(aae->values->dim);
+	    int updated = 0;
+	    for (size_t j = valuesx->dim; j; )
+	    {	j--;
+		Expression *ekey = (Expression *)aae->keys->data[j];
+		Expression *ex = Equal(TOKequal, Type::tbool, ekey, index);
+		if (ex == EXP_CANT_INTERPRET)
+		    return EXP_CANT_INTERPRET;
+		if (ex->isBool(TRUE))
+		{   valuesx->data[j] = (void *)e2;
+		    updated = 1;
+		}
+		else
+		    valuesx->data[j] = aae->values->data[j];
+	    }
+	    if (!updated)
+	    {	// Append index/e2 to keysx[]/valuesx[]
+		valuesx->push(e2);
+		keysx = (Expressions *)keysx->copy();
+		keysx->push(index);
+	    }
+	    v->value = new AssocArrayLiteralExp(aae->loc, keysx, valuesx);
+	    v->value->type = aae->type;
+	}
+	else if (se)
+	{
+	    /* Create new string literal reflecting updated elem
+	     */
+	    int elemi = index->toInteger();
+	    unsigned char *s;
+	    s = (unsigned char *)mem.calloc(se->len + 1, se->sz);
+	    memcpy(s, se->string, se->len * se->sz);
+	    unsigned value = e2->toInteger();
+	    switch (se->sz)
+	    {
+		case 1:	s[elemi] = value; break;
+		case 2:	((unsigned short *)s)[elemi] = value; break;
+		case 4:	((unsigned *)s)[elemi] = value; break;
+		default:
+		    assert(0);
+		    break;
+	    }
+	    StringExp *se2 = new StringExp(se->loc, s, se->len);
+	    se2->committed = se->committed;
+	    se2->postfix = se->postfix;
+	    se2->type = se->type;
+	    v->value = se2;
+	}
+	else
+	    assert(0);
+
+	e = Cast(type, type, post ? ev : e2);
+    }
+    else
+    {
+#ifdef DEBUG
+	dump(0);
+#endif
+    }
+    return e;
+}
+
+Expression *AssignExp::interpret(InterState *istate)
+{
+    return interpretAssignCommon(istate, NULL);
+}
+
+#define BIN_ASSIGN_INTERPRET(op) \
+Expression *op##AssignExp::interpret(InterState *istate)	\
+{								\
+    return interpretAssignCommon(istate, &op);			\
+}
+
+BIN_ASSIGN_INTERPRET(Add)
+BIN_ASSIGN_INTERPRET(Min)
+BIN_ASSIGN_INTERPRET(Cat)
+BIN_ASSIGN_INTERPRET(Mul)
+BIN_ASSIGN_INTERPRET(Div)
+BIN_ASSIGN_INTERPRET(Mod)
+BIN_ASSIGN_INTERPRET(Shl)
+BIN_ASSIGN_INTERPRET(Shr)
+BIN_ASSIGN_INTERPRET(Ushr)
+BIN_ASSIGN_INTERPRET(And)
+BIN_ASSIGN_INTERPRET(Or)
+BIN_ASSIGN_INTERPRET(Xor)
+
+Expression *PostExp::interpret(InterState *istate)
+{
+#if LOG
+    printf("PostExp::interpret() %s\n", toChars());
+#endif
+    Expression *e;
+    if (op == TOKplusplus)
+	e = interpretAssignCommon(istate, &Add, 1);
+    else
+	e = interpretAssignCommon(istate, &Min, 1);
+#if LOG
+    if (e == EXP_CANT_INTERPRET)
+	printf("PostExp::interpret() CANT\n");
+#endif
+    return e;
+}
+
+Expression *AndAndExp::interpret(InterState *istate)
+{
+#if LOG
+    printf("AndAndExp::interpret() %s\n", toChars());
+#endif
+    Expression *e = e1->interpret(istate);
+    if (e != EXP_CANT_INTERPRET)
+    {
+	if (e->isBool(FALSE))
+	    e = new IntegerExp(e1->loc, 0, type);
+	else if (e->isBool(TRUE))
+	{
+	    e = e2->interpret(istate);
+	    if (e != EXP_CANT_INTERPRET)
+	    {
+		if (e->isBool(FALSE))
+		    e = new IntegerExp(e1->loc, 0, type);
+		else if (e->isBool(TRUE))
+		    e = new IntegerExp(e1->loc, 1, type);
+		else
+		    e = EXP_CANT_INTERPRET;
+	    }
+	}
+	else
+	    e = EXP_CANT_INTERPRET;
+    }
+    return e;
+}
+
+Expression *OrOrExp::interpret(InterState *istate)
+{
+#if LOG
+    printf("OrOrExp::interpret() %s\n", toChars());
+#endif
+    Expression *e = e1->interpret(istate);
+    if (e != EXP_CANT_INTERPRET)
+    {
+	if (e->isBool(TRUE))
+	    e = new IntegerExp(e1->loc, 1, type);
+	else if (e->isBool(FALSE))
+	{
+	    e = e2->interpret(istate);
+	    if (e != EXP_CANT_INTERPRET)
+	    {
+		if (e->isBool(FALSE))
+		    e = new IntegerExp(e1->loc, 0, type);
+		else if (e->isBool(TRUE))
+		    e = new IntegerExp(e1->loc, 1, type);
+		else
+		    e = EXP_CANT_INTERPRET;
+	    }
+	}
+	else
+	    e = EXP_CANT_INTERPRET;
+    }
+    return e;
+}
+
+
+Expression *CallExp::interpret(InterState *istate)
+{   Expression *e = EXP_CANT_INTERPRET;
+
+#if LOG
+    printf("CallExp::interpret() %s\n", toChars());
+#endif
+    if (e1->op == TOKvar)
+    {
+	FuncDeclaration *fd = ((VarExp *)e1)->var->isFuncDeclaration();
+	if (fd)
+	{   // Inline .dup
+	    if (fd->ident == Id::adDup && arguments && arguments->dim == 2)
+	    {
+		e = (Expression *)arguments->data[1];
+		e = e->interpret(istate);
+		if (e != EXP_CANT_INTERPRET)
+		{
+		    e = expType(type, e);
+		}
+	    }
+	    else
+	    {
+		Expression *eresult = fd->interpret(istate, arguments);
+		if (eresult)
+		    e = eresult;
+		else if (fd->type->toBasetype()->nextOf()->ty == Tvoid)
+		    e = EXP_VOID_INTERPRET;
+		else
+		    error("cannot evaluate %s at compile time", toChars());
+	    }
+	}
+    }
+    return e;
+}
+
+Expression *CommaExp::interpret(InterState *istate)
+{
+#if LOG
+    printf("CommaExp::interpret() %s\n", toChars());
+#endif
+    Expression *e = e1->interpret(istate);
+    if (e != EXP_CANT_INTERPRET)
+	e = e2->interpret(istate);
+    return e;
+}
+
+Expression *CondExp::interpret(InterState *istate)
+{
+#if LOG
+    printf("CondExp::interpret() %s\n", toChars());
+#endif
+    Expression *e = econd->interpret(istate);
+    if (e != EXP_CANT_INTERPRET)
+    {
+	if (e->isBool(TRUE))
+	    e = e1->interpret(istate);
+	else if (e->isBool(FALSE))
+	    e = e2->interpret(istate);
+	else
+	    e = EXP_CANT_INTERPRET;
+    }
+    return e;
+}
+
+Expression *ArrayLengthExp::interpret(InterState *istate)
+{   Expression *e;
+    Expression *e1;
+
+#if LOG
+    printf("ArrayLengthExp::interpret() %s\n", toChars());
+#endif
+    e1 = this->e1->interpret(istate);
+    if (e1 == EXP_CANT_INTERPRET)
+	goto Lcant;
+    if (e1->op == TOKstring || e1->op == TOKarrayliteral || e1->op == TOKassocarrayliteral)
+    {
+	e = ArrayLength(type, e1);
+    }
+    else
+	goto Lcant;
+    return e;
+
+Lcant:
+    return EXP_CANT_INTERPRET;
+}
+
+Expression *IndexExp::interpret(InterState *istate)
+{   Expression *e;
+    Expression *e1;
+    Expression *e2;
+
+#if LOG
+    printf("IndexExp::interpret() %s\n", toChars());
+#endif
+    e1 = this->e1->interpret(istate);
+    if (e1 == EXP_CANT_INTERPRET)
+	goto Lcant;
+
+    if (e1->op == TOKstring || e1->op == TOKarrayliteral)
+    {
+	/* Set the $ variable
+	 */
+	e = ArrayLength(Type::tsize_t, e1);
+	if (e == EXP_CANT_INTERPRET)
+	    goto Lcant;
+	if (lengthVar)
+	    lengthVar->value = e;
+    }
+
+    e2 = this->e2->interpret(istate);
+    if (e2 == EXP_CANT_INTERPRET)
+	goto Lcant;
+    return Index(type, e1, e2);
+
+Lcant:
+    return EXP_CANT_INTERPRET;
+}
+
+
+Expression *SliceExp::interpret(InterState *istate)
+{   Expression *e;
+    Expression *e1;
+    Expression *lwr;
+    Expression *upr;
+
+#if LOG
+    printf("SliceExp::interpret() %s\n", toChars());
+#endif
+    e1 = this->e1->interpret(istate);
+    if (e1 == EXP_CANT_INTERPRET)
+	goto Lcant;
+    if (!this->lwr)
+    {
+	e = e1->castTo(NULL, type);
+	return e->interpret(istate);
+    }
+
+    /* Set the $ variable
+     */
+    e = ArrayLength(Type::tsize_t, e1);
+    if (e == EXP_CANT_INTERPRET)
+	goto Lcant;
+    if (lengthVar)
+	lengthVar->value = e;
+
+    /* Evaluate lower and upper bounds of slice
+     */
+    lwr = this->lwr->interpret(istate);
+    if (lwr == EXP_CANT_INTERPRET)
+	goto Lcant;
+    upr = this->upr->interpret(istate);
+    if (upr == EXP_CANT_INTERPRET)
+	goto Lcant;
+
+    return Slice(type, e1, lwr, upr);
+
+Lcant:
+    return EXP_CANT_INTERPRET;
+}
+
+
+Expression *CatExp::interpret(InterState *istate)
+{   Expression *e;
+    Expression *e1;
+    Expression *e2;
+
+#if LOG
+    printf("CatExp::interpret() %s\n", toChars());
+#endif
+    e1 = this->e1->interpret(istate);
+    if (e1 == EXP_CANT_INTERPRET)
+    {
+	goto Lcant;
+    }
+    e2 = this->e2->interpret(istate);
+    if (e2 == EXP_CANT_INTERPRET)
+	goto Lcant;
+    return Cat(type, e1, e2);
+
+Lcant:
+#if LOG
+    printf("CatExp::interpret() %s CANT\n", toChars());
+#endif
+    return EXP_CANT_INTERPRET;
+}
+
+
+Expression *CastExp::interpret(InterState *istate)
+{   Expression *e;
+    Expression *e1;
+
+#if LOG
+    printf("CastExp::interpret() %s\n", toChars());
+#endif
+    e1 = this->e1->interpret(istate);
+    if (e1 == EXP_CANT_INTERPRET)
+	goto Lcant;
+    return Cast(type, to, e1);
+
+Lcant:
+#if LOG
+    printf("CastExp::interpret() %s CANT\n", toChars());
+#endif
+    return EXP_CANT_INTERPRET;
+}
+
+
+Expression *AssertExp::interpret(InterState *istate)
+{   Expression *e;
+    Expression *e1;
+
+#if LOG
+    printf("AssertExp::interpret() %s\n", toChars());
+#endif
+    e1 = this->e1->interpret(istate);
+    if (e1 == EXP_CANT_INTERPRET)
+	goto Lcant;
+    if (e1->isBool(TRUE))
+    {
+    }
+    else if (e1->isBool(FALSE))
+    {
+	if (msg)
+	{
+	    e = msg->interpret(istate);
+	    if (e == EXP_CANT_INTERPRET)
+		goto Lcant;
+	    error("%s", e->toChars());
+	}
+	else
+	    error("%s failed", toChars());
+	goto Lcant;
+    }
+    else
+	goto Lcant;
+    return e1;
+
+Lcant:
+    return EXP_CANT_INTERPRET;
+}
+
+Expression *PtrExp::interpret(InterState *istate)
+{   Expression *e = EXP_CANT_INTERPRET;
+
+#if LOG
+    printf("PtrExp::interpret() %s\n", toChars());
+#endif
+
+    // Constant fold *(&structliteral + offset)
+    if (e1->op == TOKadd)
+    {	AddExp *ae = (AddExp *)e1;
+	if (ae->e1->op == TOKaddress && ae->e2->op == TOKint64)
+	{   AddrExp *ade = (AddrExp *)ae->e1;
+	    Expression *ex = ade->e1;
+	    ex = ex->interpret(istate);
+	    if (ex != EXP_CANT_INTERPRET)
+	    {
+		if (ex->op == TOKstructliteral)
+		{   StructLiteralExp *se = (StructLiteralExp *)ex;
+		    unsigned offset = ae->e2->toInteger();
+		    e = se->getField(type, offset);
+		    if (!e)
+			e = EXP_CANT_INTERPRET;
+		    return e;
+		}
+	    }
+	}
+	e = Ptr(type, e1);
+    }
+    else if (e1->op == TOKsymoff)
+    {	SymOffExp *soe = (SymOffExp *)e1;
+	VarDeclaration *v = soe->var->isVarDeclaration();
+	if (v)
+	{   Expression *ev = getVarExp(loc, istate, v);
+	    if (ev != EXP_CANT_INTERPRET && ev->op == TOKstructliteral)
+	    {	StructLiteralExp *se = (StructLiteralExp *)ev;
+		e = se->getField(type, soe->offset);
+		if (!e)
+		    e = EXP_CANT_INTERPRET;
+	    }
+	}
+    }
+#if LOG
+    if (e == EXP_CANT_INTERPRET)
+	printf("PtrExp::interpret() %s = EXP_CANT_INTERPRET\n", toChars());
+#endif
+    return e;
+}
+
+/******************************* Special Functions ***************************/
+
+Expression *interpret_aaLen(InterState *istate, Expressions *arguments)
+{
+    if (!arguments || arguments->dim != 1)
+	return NULL;
+    Expression *earg = (Expression *)arguments->data[0];
+    earg = earg->interpret(istate);
+    if (earg == EXP_CANT_INTERPRET)
+	return NULL;
+    if (earg->op != TOKassocarrayliteral)
+	return NULL;
+    AssocArrayLiteralExp *aae = (AssocArrayLiteralExp *)earg;
+    Expression *e = new IntegerExp(aae->loc, aae->keys->dim, Type::tsize_t);
+    return e;
+}
+
+Expression *interpret_aaKeys(InterState *istate, Expressions *arguments)
+{
+    //printf("interpret_aaKeys()\n");
+    if (!arguments || arguments->dim != 2)
+	return NULL;
+    Expression *earg = (Expression *)arguments->data[0];
+    earg = earg->interpret(istate);
+    if (earg == EXP_CANT_INTERPRET)
+	return NULL;
+    if (earg->op != TOKassocarrayliteral)
+	return NULL;
+    AssocArrayLiteralExp *aae = (AssocArrayLiteralExp *)earg;
+    Expression *e = new ArrayLiteralExp(aae->loc, aae->keys);
+    return e;
+}
+
+Expression *interpret_aaValues(InterState *istate, Expressions *arguments)
+{
+    //printf("interpret_aaValues()\n");
+    if (!arguments || arguments->dim != 3)
+	return NULL;
+    Expression *earg = (Expression *)arguments->data[0];
+    earg = earg->interpret(istate);
+    if (earg == EXP_CANT_INTERPRET)
+	return NULL;
+    if (earg->op != TOKassocarrayliteral)
+	return NULL;
+    AssocArrayLiteralExp *aae = (AssocArrayLiteralExp *)earg;
+    Expression *e = new ArrayLiteralExp(aae->loc, aae->values);
+    //printf("result is %s\n", e->toChars());
+    return e;
+}
+