1 /*
2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.nashorn.internal.codegen;
27
28 import static jdk.internal.org.objectweb.asm.Opcodes.ATHROW;
29 import static jdk.internal.org.objectweb.asm.Opcodes.CHECKCAST;
30 import static jdk.internal.org.objectweb.asm.Opcodes.DUP2;
31 import static jdk.internal.org.objectweb.asm.Opcodes.GETFIELD;
32 import static jdk.internal.org.objectweb.asm.Opcodes.GETSTATIC;
33 import static jdk.internal.org.objectweb.asm.Opcodes.GOTO;
34 import static jdk.internal.org.objectweb.asm.Opcodes.H_INVOKESTATIC;
35 import static jdk.internal.org.objectweb.asm.Opcodes.IFEQ;
36 import static jdk.internal.org.objectweb.asm.Opcodes.IFGE;
37 import static jdk.internal.org.objectweb.asm.Opcodes.IFGT;
38 import static jdk.internal.org.objectweb.asm.Opcodes.IFLE;
39 import static jdk.internal.org.objectweb.asm.Opcodes.IFLT;
40 import static jdk.internal.org.objectweb.asm.Opcodes.IFNE;
41 import static jdk.internal.org.objectweb.asm.Opcodes.IFNONNULL;
42 import static jdk.internal.org.objectweb.asm.Opcodes.IFNULL;
43 import static jdk.internal.org.objectweb.asm.Opcodes.IF_ACMPEQ;
44 import static jdk.internal.org.objectweb.asm.Opcodes.IF_ACMPNE;
45 import static jdk.internal.org.objectweb.asm.Opcodes.IF_ICMPEQ;
46 import static jdk.internal.org.objectweb.asm.Opcodes.IF_ICMPNE;
47 import static jdk.internal.org.objectweb.asm.Opcodes.INSTANCEOF;
48 import static jdk.internal.org.objectweb.asm.Opcodes.INVOKEINTERFACE;
49 import static jdk.internal.org.objectweb.asm.Opcodes.INVOKESPECIAL;
50 import static jdk.internal.org.objectweb.asm.Opcodes.INVOKESTATIC;
51 import static jdk.internal.org.objectweb.asm.Opcodes.INVOKEVIRTUAL;
52 import static jdk.internal.org.objectweb.asm.Opcodes.NEW;
53 import static jdk.internal.org.objectweb.asm.Opcodes.PUTFIELD;
54 import static jdk.internal.org.objectweb.asm.Opcodes.PUTSTATIC;
55 import static jdk.internal.org.objectweb.asm.Opcodes.RETURN;
56 import static jdk.nashorn.internal.codegen.CompilerConstants.ARGUMENTS;
57 import static jdk.nashorn.internal.codegen.CompilerConstants.CONSTANTS;
58 import static jdk.nashorn.internal.codegen.CompilerConstants.SCOPE;
59 import static jdk.nashorn.internal.codegen.CompilerConstants.THIS;
60 import static jdk.nashorn.internal.codegen.CompilerConstants.THIS_DEBUGGER;
61 import static jdk.nashorn.internal.codegen.CompilerConstants.VARARGS;
62 import static jdk.nashorn.internal.codegen.CompilerConstants.className;
63 import static jdk.nashorn.internal.codegen.CompilerConstants.constructorNoLookup;
64 import static jdk.nashorn.internal.codegen.CompilerConstants.methodDescriptor;
65 import static jdk.nashorn.internal.codegen.CompilerConstants.staticField;
66 import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCallNoLookup;
67
68 import java.io.PrintStream;
69 import java.lang.reflect.Array;
70 import java.util.EnumSet;
71 import java.util.List;
72 import jdk.internal.dynalink.support.NameCodec;
73 import jdk.internal.org.objectweb.asm.Handle;
74 import jdk.internal.org.objectweb.asm.MethodVisitor;
75 import jdk.nashorn.internal.codegen.ClassEmitter.Flag;
76 import jdk.nashorn.internal.codegen.CompilerConstants.Call;
77 import jdk.nashorn.internal.codegen.CompilerConstants.FieldAccess;
78 import jdk.nashorn.internal.codegen.types.ArrayType;
79 import jdk.nashorn.internal.codegen.types.BitwiseType;
80 import jdk.nashorn.internal.codegen.types.NumericType;
81 import jdk.nashorn.internal.codegen.types.Type;
82 import jdk.nashorn.internal.ir.FunctionNode;
83 import jdk.nashorn.internal.ir.IdentNode;
84 import jdk.nashorn.internal.ir.LexicalContext;
85 import jdk.nashorn.internal.ir.LiteralNode;
86 import jdk.nashorn.internal.ir.RuntimeNode;
87 import jdk.nashorn.internal.ir.Symbol;
88 import jdk.nashorn.internal.runtime.ArgumentSetter;
89 import jdk.nashorn.internal.runtime.Debug;
90 import jdk.nashorn.internal.runtime.DebugLogger;
91 import jdk.nashorn.internal.runtime.JSType;
92 import jdk.nashorn.internal.runtime.ScriptEnvironment;
93 import jdk.nashorn.internal.runtime.ScriptObject;
94 import jdk.nashorn.internal.runtime.linker.Bootstrap;
95 import jdk.nashorn.internal.runtime.options.Options;
96
97 /**
98 * This is the main function responsible for emitting method code
99 * in a class. It maintains a type stack and keeps track of control
100 * flow to make sure that the registered instructions don't violate
101 * byte code verification.
102 *
103 * Running Nashorn with -ea will assert as soon as a type stack
104 * becomes corrupt, for easier debugging
105 *
106 * Running Nashorn with -Dnashorn.codegen.debug=true will print
107 * all generated bytecode and labels to stderr, for easier debugging,
108 * including bytecode stack contents
109 */
110 public class MethodEmitter implements Emitter {
111 /** The ASM MethodVisitor we are plugged into */
112 private final MethodVisitor method;
113
114 /** Current type stack for current evaluation */
115 private Label.Stack stack;
116
117 /** Parent classEmitter representing the class of this method */
118 private final ClassEmitter classEmitter;
119
120 /** FunctionNode representing this method, or null if none exists */
121 protected FunctionNode functionNode;
122
123 /** Check whether this emitter ever has a function return point */
124 private boolean hasReturn;
125
126 /** The script environment */
127 private final ScriptEnvironment env;
128
129 /** Threshold in chars for when string constants should be split */
130 static final int LARGE_STRING_THRESHOLD = 32 * 1024;
131
132 /** Debug flag, should we dump all generated bytecode along with stacks? */
133 private static final DebugLogger LOG = new DebugLogger("codegen", "nashorn.codegen.debug");
134 private static final boolean DEBUG = LOG.isEnabled();
135
136 /** dump stack on a particular line, or -1 if disabled */
137 private static final int DEBUG_TRACE_LINE;
138
139 static {
140 final String tl = Options.getStringProperty("nashorn.codegen.debug.trace", "-1");
141 int line = -1;
142 try {
143 line = Integer.parseInt(tl);
144 } catch (final NumberFormatException e) {
145 //fallthru
146 }
147 DEBUG_TRACE_LINE = line;
148 }
149
150 /** Bootstrap for normal indy:s */
151 private static final Handle LINKERBOOTSTRAP = new Handle(H_INVOKESTATIC, Bootstrap.BOOTSTRAP.className(), Bootstrap.BOOTSTRAP.name(), Bootstrap.BOOTSTRAP.descriptor());
152
153 /** Bootstrap for runtime node indy:s */
154 private static final Handle RUNTIMEBOOTSTRAP = new Handle(H_INVOKESTATIC, RuntimeCallSite.BOOTSTRAP.className(), RuntimeCallSite.BOOTSTRAP.name(), RuntimeCallSite.BOOTSTRAP.descriptor());
155
156 /**
157 * Constructor - internal use from ClassEmitter only
158 * @see ClassEmitter#method
159 *
160 * @param classEmitter the class emitter weaving the class this method is in
161 * @param method a method visitor
162 */
163 MethodEmitter(final ClassEmitter classEmitter, final MethodVisitor method) {
164 this(classEmitter, method, null);
165 }
166
167 /**
168 * Constructor - internal use from ClassEmitter only
169 * @see ClassEmitter#method
170 *
171 * @param classEmitter the class emitter weaving the class this method is in
172 * @param method a method visitor
173 * @param functionNode a function node representing this method
174 */
175 MethodEmitter(final ClassEmitter classEmitter, final MethodVisitor method, final FunctionNode functionNode) {
176 this.env = classEmitter.getEnv();
177 this.classEmitter = classEmitter;
178 this.method = method;
179 this.functionNode = functionNode;
180 this.stack = null;
181 }
182
183 /**
184 * Begin a method
185 * @see Emitter
186 */
187 @Override
188 public void begin() {
189 classEmitter.beginMethod(this);
190 newStack();
191 method.visitCode();
192 }
193
194 /**
195 * End a method
196 * @see Emitter
197 */
198 @Override
199 public void end() {
200 method.visitMaxs(0, 0);
201 method.visitEnd();
202
203 classEmitter.endMethod(this);
204 }
205
206 private void newStack() {
207 stack = new Label.Stack();
208 }
209
210 @Override
211 public String toString() {
212 return "methodEmitter: " + (functionNode == null ? method : functionNode.getName()).toString() + ' ' + Debug.id(this);
213 }
214
215 /**
216 * Push a type to the existing stack
217 * @param type the type
218 */
219 private void pushType(final Type type) {
220 if (type != null) {
221 stack.push(type);
222 }
223 }
224
225 /**
226 * Pop a type from the existing stack
227 *
228 * @param expected expected type - will assert if wrong
229 *
230 * @return the type that was retrieved
231 */
232 private Type popType(final Type expected) {
233 final Type type = stack.pop();
234 assert type.isObject() && expected.isObject() ||
235 type.isEquivalentTo(expected) : type + " is not compatible with " + expected;
236 return type;
237 }
238
239 /**
240 * Pop a type from the existing stack, no matter what it is.
241 *
242 * @return the type
243 */
244 private Type popType() {
245 return stack.pop();
246 }
247
248 /**
249 * Pop a type from the existing stack, ensuring that it is numeric,
250 * assert if not
251 *
252 * @return the type
253 */
254 private NumericType popNumeric() {
255 final Type type = stack.pop();
256 assert type.isNumeric() : type + " is not numeric";
257 return (NumericType)type;
258 }
259
260 /**
261 * Pop a type from the existing stack, ensuring that it is an integer type
262 * (integer or long), assert if not
263 *
264 * @return the type
265 */
266 private BitwiseType popInteger() {
267 final Type type = stack.pop();
268 assert type.isInteger() || type.isLong() : type + " is not an integer or long";
269 return (BitwiseType)type;
270 }
271
272 /**
273 * Pop a type from the existing stack, ensuring that it is an array type,
274 * assert if not
275 *
276 * @return the type
277 */
278 private ArrayType popArray() {
279 final Type type = stack.pop();
280 assert type.isArray() : type;
281 return (ArrayType)type;
282 }
283
284 /**
285 * Peek a given number of slots from the top of the stack and return the
286 * type in that slot
287 *
288 * @param pos the number of positions from the top, 0 is the top element
289 *
290 * @return the type at position "pos" on the stack
291 */
292 final Type peekType(final int pos) {
293 return stack.peek(pos);
294 }
295
296 /**
297 * Peek at the type at the top of the stack
298 *
299 * @return the type at the top of the stack
300 */
301 final Type peekType() {
302 return stack.peek();
303 }
304
305 /**
306 * Generate code a for instantiating a new object and push the
307 * object type on the stack
308 *
309 * @param classDescriptor class descriptor for the object type
310 *
311 * @return the method emitter
312 */
313 MethodEmitter _new(final String classDescriptor) {
314 debug("new", classDescriptor);
315 method.visitTypeInsn(NEW, classDescriptor);
316 pushType(Type.OBJECT);
317 return this;
318 }
319
320 /**
321 * Generate code a for instantiating a new object and push the
322 * object type on the stack
323 *
324 * @param clazz class type to instatiate
325 *
326 * @return the method emitter
327 */
328 MethodEmitter _new(final Class<?> clazz) {
329 return _new(className(clazz));
330 }
331
332 /**
333 * Generate code to call the empty constructor for a class
334 *
335 * @param clazz class type to instatiate
336 *
337 * @return the method emitter
338 */
339 MethodEmitter newInstance(final Class<?> clazz) {
340 return invoke(constructorNoLookup(clazz));
341 }
342
343 /**
344 * Perform a dup, that is, duplicate the top element and
345 * push the duplicate down a given number of positions
346 * on the stack. This is totally type agnostic.
347 *
348 * @param depth the depth on which to put the copy
349 *
350 * @return the method emitter, or null if depth is illegal and
351 * has no instruction equivalent.
352 */
353 MethodEmitter dup(final int depth) {
354 if (peekType().dup(method, depth) == null) {
355 return null;
356 }
357
358 debug("dup", depth);
359
360 switch (depth) {
361 case 0:
362 pushType(peekType());
363 break;
364 case 1: {
365 final Type p0 = popType();
366 final Type p1 = popType();
367 pushType(p0);
368 pushType(p1);
369 pushType(p0);
370 break;
371 }
372 case 2: {
373 final Type p0 = popType();
374 final Type p1 = popType();
375 final Type p2 = popType();
376 pushType(p0);
377 pushType(p2);
378 pushType(p1);
379 pushType(p0);
380 break;
381 }
382 default:
383 assert false : "illegal dup depth = " + depth;
384 return null;
385 }
386
387 return this;
388 }
389
390 /**
391 * Perform a dup2, that is, duplicate the top element if it
392 * is a category 2 type, or two top elements if they are category
393 * 1 types, and push them on top of the stack
394 *
395 * @return the method emitter
396 */
397 MethodEmitter dup2() {
398 debug("dup2");
399
400 if (peekType().isCategory2()) {
401 pushType(peekType());
402 } else {
403 final Type type = get2();
404 pushType(type);
405 pushType(type);
406 pushType(type);
407 pushType(type);
408 }
409 method.visitInsn(DUP2);
410 return this;
411 }
412
413 /**
414 * Duplicate the top element on the stack and push it
415 *
416 * @return the method emitter
417 */
418 MethodEmitter dup() {
419 return dup(0);
420 }
421
422 /**
423 * Pop the top element of the stack and throw it away
424 *
425 * @return the method emitter
426 */
427 MethodEmitter pop() {
428 debug("pop", peekType());
429 popType().pop(method);
430 return this;
431 }
432
433 /**
434 * Pop the top element of the stack if category 2 type, or the two
435 * top elements of the stack if category 1 types
436 *
437 * @return the method emitter
438 */
439 MethodEmitter pop2() {
440 if (peekType().isCategory2()) {
441 popType();
442 } else {
443 get2n();
444 }
445 return this;
446 }
447
448 /**
449 * Swap the top two elements of the stack. This is totally
450 * type agnostic and works for all types
451 *
452 * @return the method emitter
453 */
454 MethodEmitter swap() {
455 debug("swap");
456
457 final Type p0 = popType();
458 final Type p1 = popType();
459 p0.swap(method, p1);
460
461 pushType(p0);
462 pushType(p1);
463 debug("after ", p0, p1);
464 return this;
465 }
466
467 /**
468 * Add a local variable. This is a nop if the symbol has no slot
469 *
470 * @param symbol symbol for the local variable
471 * @param start start of scope
472 * @param end end of scope
473 */
474 void localVariable(final Symbol symbol, final Label start, final Label end) {
475 if (!symbol.hasSlot()) {
476 return;
477 }
478
479 String name = symbol.getName();
480
481 if (name.equals(THIS.symbolName())) {
482 name = THIS_DEBUGGER.symbolName();
483 }
484
485 method.visitLocalVariable(name, symbol.getSymbolType().getDescriptor(), null, start.getLabel(), end.getLabel(), symbol.getSlot());
486 }
487
488 /**
489 * Create a new string builder, call the constructor and push the instance to the stack.
490 *
491 * @return the method emitter
492 */
493 MethodEmitter newStringBuilder() {
494 return invoke(constructorNoLookup(StringBuilder.class)).dup();
495 }
496
497 /**
498 * Pop a string and a StringBuilder from the top of the stack and call the append
499 * function of the StringBuilder, appending the string. Pushes the StringBuilder to
500 * the stack when finished.
501 *
502 * @return the method emitter
503 */
504 MethodEmitter stringBuilderAppend() {
505 convert(Type.STRING);
506 return invoke(virtualCallNoLookup(StringBuilder.class, "append", StringBuilder.class, String.class));
507 }
508
509 /**
510 * Pops two integer types from the stack, performs a bitwise and and pushes
511 * the result
512 *
513 * @return the method emitter
514 */
515 MethodEmitter and() {
516 debug("and");
517 pushType(get2i().and(method));
518 return this;
519 }
520
521 /**
522 * Pops two integer types from the stack, performs a bitwise or and pushes
523 * the result
524 *
525 * @return the method emitter
526 */
527 MethodEmitter or() {
528 debug("or");
529 pushType(get2i().or(method));
530 return this;
531 }
532
533 /**
534 * Pops two integer types from the stack, performs a bitwise xor and pushes
535 * the result
536 *
537 * @return the method emitter
538 */
539 MethodEmitter xor() {
540 debug("xor");
541 pushType(get2i().xor(method));
542 return this;
543 }
544
545 /**
546 * Pops two integer types from the stack, performs a bitwise logic shift right and pushes
547 * the result. The shift count, the first element, must be INT.
548 *
549 * @return the method emitter
550 */
551 MethodEmitter shr() {
552 debug("shr");
553 popType(Type.INT);
554 pushType(popInteger().shr(method));
555 return this;
556 }
557
558 /**
559 * Pops two integer types from the stack, performs a bitwise shift left and and pushes
560 * the result. The shift count, the first element, must be INT.
561 *
562 * @return the method emitter
563 */
564 MethodEmitter shl() {
565 debug("shl");
566 popType(Type.INT);
567 pushType(popInteger().shl(method));
568 return this;
569 }
570
571 /**
572 * Pops two integer types from the stack, performs a bitwise arithetic shift right and pushes
573 * the result. The shift count, the first element, must be INT.
574 *
575 * @return the method emitter
576 */
577 MethodEmitter sar() {
578 debug("sar");
579 popType(Type.INT);
580 pushType(popInteger().sar(method));
581 return this;
582 }
583
584 /**
585 * Pops a numeric type from the stack, negates it and pushes the result
586 *
587 * @return the method emitter
588 */
589 MethodEmitter neg() {
590 debug("neg");
591 pushType(popNumeric().neg(method));
592 return this;
593 }
594
595 /**
596 * Add label for the start of a catch block and push the exception to the
597 * stack
598 *
599 * @param recovery label pointing to start of catch block
600 */
601 void _catch(final Label recovery) {
602 stack.clear();
603 stack.push(Type.OBJECT);
604 label(recovery);
605 }
606
607 /**
608 * Start a try/catch block.
609 *
610 * @param entry start label for try
611 * @param exit end label for try
612 * @param recovery start label for catch
613 * @param typeDescriptor type descriptor for exception
614 */
615 void _try(final Label entry, final Label exit, final Label recovery, final String typeDescriptor) {
616 method.visitTryCatchBlock(entry.getLabel(), exit.getLabel(), recovery.getLabel(), typeDescriptor);
617 }
618
619 /**
620 * Start a try/catch block.
621 *
622 * @param entry start label for try
623 * @param exit end label for try
624 * @param recovery start label for catch
625 * @param clazz exception class
626 */
627 void _try(final Label entry, final Label exit, final Label recovery, final Class<?> clazz) {
628 method.visitTryCatchBlock(entry.getLabel(), exit.getLabel(), recovery.getLabel(), CompilerConstants.className(clazz));
629 }
630
631 /**
632 * Start a try/catch block. The catch is "Throwable" - i.e. catch-all
633 *
634 * @param entry start label for try
635 * @param exit end label for try
636 * @param recovery start label for catch
637 */
638 void _try(final Label entry, final Label exit, final Label recovery) {
639 _try(entry, exit, recovery, (String)null);
640 }
641
642
643 /**
644 * Load the constants array
645 * @return this method emitter
646 */
647 MethodEmitter loadConstants() {
648 getStatic(classEmitter.getUnitClassName(), CONSTANTS.symbolName(), CONSTANTS.descriptor());
649 assert peekType().isArray() : peekType();
650 return this;
651 }
652
653 /**
654 * Push the undefined value for the given type, i.e.
655 * UNDEFINED or UNDEFINEDNUMBER. Currently we have no way of
656 * representing UNDEFINED for INTs and LONGs, so they are not
657 * allowed to be local variables (yet)
658 *
659 * @param type the type for which to push UNDEFINED
660 * @return the method emitter
661 */
662 MethodEmitter loadUndefined(final Type type) {
663 debug("load undefined ", type);
664 pushType(type.loadUndefined(method));
665 return this;
666 }
667
668 /**
669 * Push the empty value for the given type, i.e. EMPTY.
670 *
671 * @param type the type
672 * @return the method emitter
673 */
674 MethodEmitter loadEmpty(final Type type) {
675 debug("load empty ", type);
676 pushType(type.loadEmpty(method));
677 return this;
678 }
679
680 /**
681 * Push null to stack
682 *
683 * @return the method emitter
684 */
685 MethodEmitter loadNull() {
686 debug("aconst_null");
687 pushType(Type.OBJECT.ldc(method, null));
688 return this;
689 }
690
691 /**
692 * Push a handle representing this class top stack
693 *
694 * @param className name of the class
695 *
696 * @return the method emitter
697 */
698 MethodEmitter loadType(final String className) {
699 debug("load type", className);
700 method.visitLdcInsn(jdk.internal.org.objectweb.asm.Type.getObjectType(className));
701 pushType(Type.OBJECT);
702 return this;
703 }
704
705 /**
706 * Push a boolean constant to the stack.
707 *
708 * @param b value of boolean
709 *
710 * @return the method emitter
711 */
712 MethodEmitter load(final boolean b) {
713 debug("load boolean", b);
714 pushType(Type.BOOLEAN.ldc(method, b));
715 return this;
716 }
717
718 /**
719 * Push an int constant to the stack
720 *
721 * @param i value of the int
722 *
723 * @return the method emitter
724 */
725 MethodEmitter load(final int i) {
726 debug("load int", i);
727 pushType(Type.INT.ldc(method, i));
728 return this;
729 }
730
731 /**
732 * Push a double constant to the stack
733 *
734 * @param d value of the double
735 *
736 * @return the method emitter
737 */
738 MethodEmitter load(final double d) {
739 debug("load double", d);
740 pushType(Type.NUMBER.ldc(method, d));
741 return this;
742 }
743
744 /**
745 * Push an long constant to the stack
746 *
747 * @param l value of the long
748 *
749 * @return the method emitter
750 */
751 MethodEmitter load(final long l) {
752 debug("load long", l);
753 pushType(Type.LONG.ldc(method, l));
754 return this;
755 }
756
757 /**
758 * Fetch the length of an array.
759 * @return Array length.
760 */
761 MethodEmitter arraylength() {
762 debug("arraylength");
763 popType(Type.OBJECT);
764 pushType(Type.OBJECT_ARRAY.arraylength(method));
765 return this;
766 }
767
768 /**
769 * Push a String constant to the stack
770 *
771 * @param s value of the String
772 *
773 * @return the method emitter
774 */
775 MethodEmitter load(final String s) {
776 debug("load string", s);
777
778 if (s == null) {
779 loadNull();
780 return this;
781 }
782
783 //NASHORN-142 - split too large string
784 final int length = s.length();
785 if (length > LARGE_STRING_THRESHOLD) {
786
787 _new(StringBuilder.class);
788 dup();
789 load(length);
790 invoke(constructorNoLookup(StringBuilder.class, int.class));
791
792 for (int n = 0; n < length; n += LARGE_STRING_THRESHOLD) {
793 final String part = s.substring(n, Math.min(n + LARGE_STRING_THRESHOLD, length));
794 load(part);
795 stringBuilderAppend();
796 }
797
798 invoke(virtualCallNoLookup(StringBuilder.class, "toString", String.class));
799
800 return this;
801 }
802
803 pushType(Type.OBJECT.ldc(method, s));
804 return this;
805 }
806
807 /**
808 * Push a local variable to the stack. If the symbol representing
809 * the local variable doesn't have a slot, this is a NOP
810 *
811 * @param symbol the symbol representing the local variable.
812 *
813 * @return the method emitter
814 */
815 MethodEmitter load(final Symbol symbol) {
816 assert symbol != null;
817 if (symbol.hasSlot()) {
818 final int slot = symbol.getSlot();
819 debug("load symbol", symbol.getName(), " slot=", slot);
820 final Type type = symbol.getSymbolType().load(method, slot);
821 pushType(type == Type.OBJECT && symbol.isThis() ? Type.THIS : type);
822 } else if (symbol.isParam()) {
823 assert !symbol.isScope();
824 assert functionNode.isVarArg() : "Non-vararg functions have slotted parameters";
825 final int index = symbol.getFieldIndex();
826 if (functionNode.needsArguments()) {
827 // ScriptObject.getArgument(int) on arguments
828 debug("load symbol", symbol.getName(), " arguments index=", index);
829 loadCompilerConstant(ARGUMENTS);
830 load(index);
831 ScriptObject.GET_ARGUMENT.invoke(this);
832 } else {
833 // array load from __varargs__
834 debug("load symbol", symbol.getName(), " array index=", index);
835 loadCompilerConstant(VARARGS);
836 load(symbol.getFieldIndex());
837 arrayload();
838 }
839 }
840 return this;
841 }
842
843 /**
844 * Push a local variable to the stack, given an explicit bytecode slot
845 * This is used e.g. for stub generation where we know where items like
846 * "this" and "scope" reside.
847 *
848 * @param type the type of the variable
849 * @param slot the slot the variable is in
850 *
851 * @return the method emitter
852 */
853 MethodEmitter load(final Type type, final int slot) {
854 debug("explicit load", type, slot);
855 final Type loadType = type.load(method, slot);
856 pushType(loadType == Type.OBJECT && isThisSlot(slot) ? Type.THIS : loadType);
857 return this;
858 }
859
860 private boolean isThisSlot(final int slot) {
861 if (functionNode == null) {
862 return slot == CompilerConstants.JAVA_THIS.slot();
863 }
864 final int thisSlot = compilerConstant(THIS).getSlot();
865 assert !functionNode.needsCallee() || thisSlot == 1; // needsCallee -> thisSlot == 1
866 assert functionNode.needsCallee() || thisSlot == 0; // !needsCallee -> thisSlot == 0
867 return slot == thisSlot;
868 }
869
870 /**
871 * Push a method handle to the stack
872 *
873 * @param className class name
874 * @param methodName method name
875 * @param descName descriptor
876 * @param flags flags that describe this handle, e.g. invokespecial new, or invoke virtual
877 *
878 * @return the method emitter
879 */
880 MethodEmitter loadHandle(final String className, final String methodName, final String descName, final EnumSet<Flag> flags) {
881 debug("load handle ");
882 pushType(Type.OBJECT.ldc(method, new Handle(Flag.getValue(flags), className, methodName, descName)));
883 return this;
884 }
885
886 private Symbol compilerConstant(final CompilerConstants cc) {
887 return functionNode.getBody().getExistingSymbol(cc.symbolName());
888 }
889
890 /**
891 * True if this method has a slot allocated for the scope variable (meaning, something in the method actually needs
892 * the scope).
893 * @return if this method has a slot allocated for the scope variable.
894 */
895 boolean hasScope() {
896 return compilerConstant(SCOPE).hasSlot();
897 }
898
899 MethodEmitter loadCompilerConstant(final CompilerConstants cc) {
900 final Symbol symbol = compilerConstant(cc);
901 if (cc == SCOPE && peekType() == Type.SCOPE) {
902 dup();
903 return this;
904 }
905 return load(symbol);
906 }
907
908 void storeCompilerConstant(final CompilerConstants cc) {
909 final Symbol symbol = compilerConstant(cc);
910 debug("store compiler constant ", symbol);
911 store(symbol);
912 }
913
914 /**
915 * Load an element from an array, determining type automatically
916 * @return the method emitter
917 */
918 MethodEmitter arrayload() {
919 debug("Xaload");
920 popType(Type.INT);
921 pushType(popArray().aload(method));
922 return this;
923 }
924
925 /**
926 * Pop a value, an index and an array from the stack and store
927 * the value at the given index in the array.
928 */
929 void arraystore() {
930 debug("Xastore");
931 final Type value = popType();
932 final Type index = popType(Type.INT);
933 assert index.isInteger() : "array index is not integer, but " + index;
934 final ArrayType array = popArray();
935
936 assert value.isEquivalentTo(array.getElementType()) : "Storing "+value+" into "+array;
937 assert array.isObject();
938 array.astore(method);
939 }
940
941 /**
942 * Pop a value from the stack and store it in a local variable represented
943 * by the given symbol. If the symbol has no slot, this is a NOP
944 *
945 * @param symbol symbol to store stack to
946 */
947 void store(final Symbol symbol) {
948 assert symbol != null : "No symbol to store";
949 if (symbol.hasSlot()) {
950 final int slot = symbol.getSlot();
951 debug("store symbol", symbol.getName(), " slot=", slot);
952 popType(symbol.getSymbolType()).store(method, slot);
953 } else if (symbol.isParam()) {
954 assert !symbol.isScope();
955 assert functionNode.isVarArg() : "Non-vararg functions have slotted parameters";
956 final int index = symbol.getFieldIndex();
957 if (functionNode.needsArguments()) {
958 debug("store symbol", symbol.getName(), " arguments index=", index);
959 loadCompilerConstant(ARGUMENTS);
960 load(index);
961 ArgumentSetter.SET_ARGUMENT.invoke(this);
962 } else {
963 // varargs without arguments object - just do array store to __varargs__
964 debug("store symbol", symbol.getName(), " array index=", index);
965 loadCompilerConstant(VARARGS);
966 load(index);
967 ArgumentSetter.SET_ARRAY_ELEMENT.invoke(this);
968 }
969 }
970 }
971
972 /**
973 * Pop a value from the stack and store it in a given local variable
974 * slot.
975 *
976 * @param type the type to pop
977 * @param slot the slot
978 */
979 void store(final Type type, final int slot) {
980 popType(type);
981 type.store(method, slot);
982 }
983
984 /**
985 * Increment/Decrement a local integer by the given value.
986 *
987 * @param slot the int slot
988 * @param increment the amount to increment
989 */
990 void iinc(final int slot, final int increment) {
991 debug("iinc");
992 method.visitIincInsn(slot, increment);
993 }
994
995 /**
996 * Pop an exception object from the stack and generate code
997 * for throwing it
998 */
999 public void athrow() {
1000 debug("athrow");
1001 final Type receiver = popType(Type.OBJECT);
1002 assert receiver.isObject();
1003 method.visitInsn(ATHROW);
1004 stack = null;
1005 }
1006
1007 /**
1008 * Pop an object from the stack and perform an instanceof
1009 * operation, given a classDescriptor to compare it to.
1010 * Push the boolean result 1/0 as an int to the stack
1011 *
1012 * @param classDescriptor descriptor of the class to type check against
1013 *
1014 * @return the method emitter
1015 */
1016 MethodEmitter _instanceof(final String classDescriptor) {
1017 debug("instanceof", classDescriptor);
1018 popType(Type.OBJECT);
1019 method.visitTypeInsn(INSTANCEOF, classDescriptor);
1020 pushType(Type.INT);
1021 return this;
1022 }
1023
1024 /**
1025 * Pop an object from the stack and perform an instanceof
1026 * operation, given a classDescriptor to compare it to.
1027 * Push the boolean result 1/0 as an int to the stack
1028 *
1029 * @param clazz the type to check instanceof against
1030 *
1031 * @return the method emitter
1032 */
1033 MethodEmitter _instanceof(final Class<?> clazz) {
1034 return _instanceof(CompilerConstants.className(clazz));
1035 }
1036
1037 /**
1038 * Perform a checkcast operation on the object at the top of the
1039 * stack.
1040 *
1041 * @param classDescriptor descriptor of the class to type check against
1042 *
1043 * @return the method emitter
1044 */
1045 MethodEmitter checkcast(final String classDescriptor) {
1046 debug("checkcast", classDescriptor);
1047 assert peekType().isObject();
1048 method.visitTypeInsn(CHECKCAST, classDescriptor);
1049 return this;
1050 }
1051
1052 /**
1053 * Perform a checkcast operation on the object at the top of the
1054 * stack.
1055 *
1056 * @param clazz class to checkcast against
1057 *
1058 * @return the method emitter
1059 */
1060 MethodEmitter checkcast(final Class<?> clazz) {
1061 return checkcast(CompilerConstants.className(clazz));
1062 }
1063
1064 /**
1065 * Instantiate a new array given a length that is popped
1066 * from the stack and the array type
1067 *
1068 * @param arrayType the type of the array
1069 *
1070 * @return the method emitter
1071 */
1072 MethodEmitter newarray(final ArrayType arrayType) {
1073 debug("newarray ", "arrayType=", arrayType);
1074 popType(Type.INT); //LENGTH
1075 pushType(arrayType.newarray(method));
1076 return this;
1077 }
1078
1079 /**
1080 * Instantiate a multidimensional array with a given number of dimensions.
1081 * On the stack are dim lengths of the sub arrays.
1082 *
1083 * @param arrayType type of the array
1084 * @param dims number of dimensions
1085 *
1086 * @return the method emitter
1087 */
1088 MethodEmitter multinewarray(final ArrayType arrayType, final int dims) {
1089 debug("multianewarray ", arrayType, dims);
1090 for (int i = 0; i < dims; i++) {
1091 popType(Type.INT); //LENGTH
1092 }
1093 pushType(arrayType.newarray(method, dims));
1094 return this;
1095 }
1096
1097 /**
1098 * Helper function to pop and type check the appropriate arguments
1099 * from the stack given a method signature
1100 *
1101 * @param signature method signature
1102 *
1103 * @return return type of method
1104 */
1105 private Type fixParamStack(final String signature) {
1106 final Type[] params = Type.getMethodArguments(signature);
1107 for (int i = params.length - 1; i >= 0; i--) {
1108 popType(params[i]);
1109 }
1110 final Type returnType = Type.getMethodReturnType(signature);
1111 return returnType;
1112 }
1113
1114 /**
1115 * Generate an invocation to a Call structure
1116 * @see CompilerConstants
1117 *
1118 * @param call the call object
1119 *
1120 * @return the method emitter
1121 */
1122 MethodEmitter invoke(final Call call) {
1123 return call.invoke(this);
1124 }
1125
1126 private MethodEmitter invoke(final int opcode, final String className, final String methodName, final String methodDescriptor, final boolean hasReceiver) {
1127 final Type returnType = fixParamStack(methodDescriptor);
1128
1129 if (hasReceiver) {
1130 popType(Type.OBJECT);
1131 }
1132
1133 method.visitMethodInsn(opcode, className, methodName, methodDescriptor);
1134
1135 if (returnType != null) {
1136 pushType(returnType);
1137 }
1138
1139 return this;
1140 }
1141
1142 /**
1143 * Pop receiver from stack, perform an invoke special
1144 *
1145 * @param className class name
1146 * @param methodName method name
1147 * @param methodDescriptor descriptor
1148 *
1149 * @return the method emitter
1150 */
1151 MethodEmitter invokespecial(final String className, final String methodName, final String methodDescriptor) {
1152 debug("invokespecial", className, ".", methodName, methodDescriptor);
1153 return invoke(INVOKESPECIAL, className, methodName, methodDescriptor, true);
1154 }
1155
1156 /**
1157 * Pop receiver from stack, perform an invoke virtual, push return value if any
1158 *
1159 * @param className class name
1160 * @param methodName method name
1161 * @param methodDescriptor descriptor
1162 *
1163 * @return the method emitter
1164 */
1165 MethodEmitter invokevirtual(final String className, final String methodName, final String methodDescriptor) {
1166 debug("invokevirtual", className, ".", methodName, methodDescriptor, " ", stack);
1167 return invoke(INVOKEVIRTUAL, className, methodName, methodDescriptor, true);
1168 }
1169
1170 /**
1171 * Perform an invoke static and push the return value if any
1172 *
1173 * @param className class name
1174 * @param methodName method name
1175 * @param methodDescriptor descriptor
1176 *
1177 * @return the method emitter
1178 */
1179 MethodEmitter invokestatic(final String className, final String methodName, final String methodDescriptor) {
1180 debug("invokestatic", className, ".", methodName, methodDescriptor);
1181 invoke(INVOKESTATIC, className, methodName, methodDescriptor, false);
1182 return this;
1183 }
1184
1185 /**
1186 * Perform an invoke static and replace the return type if we know better, e.g. Global.allocate
1187 * that allocates an array should return an ObjectArray type as a NativeArray counts as that
1188 *
1189 * @param className class name
1190 * @param methodName method name
1191 * @param methodDescriptor descriptor
1192 * @param returnType return type override
1193 *
1194 * @return the method emitter
1195 */
1196 MethodEmitter invokeStatic(final String className, final String methodName, final String methodDescriptor, final Type returnType) {
1197 invokestatic(className, methodName, methodDescriptor);
1198 popType();
1199 pushType(returnType);
1200 return this;
1201 }
1202
1203 /**
1204 * Pop receiver from stack, perform an invoke interface and push return value if any
1205 *
1206 * @param className class name
1207 * @param methodName method name
1208 * @param methodDescriptor descriptor
1209 *
1210 * @return the method emitter
1211 */
1212 MethodEmitter invokeinterface(final String className, final String methodName, final String methodDescriptor) {
1213 debug("invokeinterface", className, ".", methodName, methodDescriptor);
1214 return invoke(INVOKEINTERFACE, className, methodName, methodDescriptor, true);
1215 }
1216
1217 static jdk.internal.org.objectweb.asm.Label[] getLabels(final Label... table) {
1218 final jdk.internal.org.objectweb.asm.Label[] internalLabels = new jdk.internal.org.objectweb.asm.Label[table.length];
1219 for (int i = 0; i < table.length; i++) {
1220 internalLabels[i] = table[i].getLabel();
1221 }
1222 return internalLabels;
1223 }
1224
1225 /**
1226 * Generate a lookup switch, popping the switch value from the stack
1227 *
1228 * @param defaultLabel default label
1229 * @param values case values for the table
1230 * @param table default label
1231 */
1232 void lookupswitch(final Label defaultLabel, final int[] values, final Label... table) {//Collection<Label> table) {
1233 debug("lookupswitch", peekType());
1234 popType(Type.INT);
1235 method.visitLookupSwitchInsn(defaultLabel.getLabel(), values, getLabels(table));
1236 }
1237
1238 /**
1239 * Generate a table switch
1240 * @param lo low value
1241 * @param hi high value
1242 * @param defaultLabel default label
1243 * @param table label table
1244 */
1245 void tableswitch(final int lo, final int hi, final Label defaultLabel, final Label... table) {
1246 debug("tableswitch", peekType());
1247 popType(Type.INT);
1248 method.visitTableSwitchInsn(lo, hi, defaultLabel.getLabel(), getLabels(table));
1249 }
1250
1251 /**
1252 * Abstraction for performing a conditional jump of any type
1253 *
1254 * @see MethodEmitter.Condition
1255 *
1256 * @param cond the condition to test
1257 * @param trueLabel the destination label is condition is true
1258 */
1259 void conditionalJump(final Condition cond, final Label trueLabel) {
1260 conditionalJump(cond, cond != Condition.GT && cond != Condition.GE, trueLabel);
1261 }
1262
1263 /**
1264 * Abstraction for performing a conditional jump of any type,
1265 * including a dcmpg/dcmpl semantic for doubles.
1266 *
1267 * @param cond the condition to test
1268 * @param isCmpG is this a dcmpg for numbers, false if it's a dcmpl
1269 * @param trueLabel the destination label if condition is true
1270 */
1271 void conditionalJump(final Condition cond, final boolean isCmpG, final Label trueLabel) {
1272 if (peekType().isCategory2()) {
1273 debug("[ld]cmp isCmpG=", isCmpG);
1274 pushType(get2n().cmp(method, isCmpG));
1275 jump(Condition.toUnary(cond), trueLabel, 1);
1276 } else {
1277 debug("if", cond);
1278 jump(Condition.toBinary(cond, peekType().isObject()), trueLabel, 2);
1279 }
1280 }
1281
1282 MethodEmitter registerReturn() {
1283 setHasReturn();
1284 return this;
1285 }
1286
1287 void setHasReturn() {
1288 this.hasReturn = true;
1289 }
1290
1291 /**
1292 * Perform a non void return, popping the type from the stack
1293 *
1294 * @param type the type for the return
1295 */
1296 void _return(final Type type) {
1297 debug("return", type);
1298 assert stack.size() == 1 : "Only return value on stack allowed at return point - depth=" + stack.size() + " stack = " + stack;
1299 final Type stackType = peekType();
1300 if (!Type.areEquivalent(type, stackType)) {
1301 convert(type);
1302 }
1303 popType(type)._return(method);
1304 stack = null;
1305 }
1306
1307 /**
1308 * Perform a return using the stack top value as the guide for the type
1309 */
1310 void _return() {
1311 _return(peekType());
1312 }
1313
1314 /**
1315 * Perform a void return.
1316 */
1317 void returnVoid() {
1318 debug("return [void]");
1319 assert stack.isEmpty() : stack;
1320 method.visitInsn(RETURN);
1321 stack = null;
1322 }
1323
1324 /**
1325 * Goto, possibly when splitting is taking place. If
1326 * a splitNode exists, we need to handle the case that the
1327 * jump target is another method
1328 *
1329 * @param label destination label
1330 */
1331 void splitAwareGoto(final LexicalContext lc, final Label label) {
1332 _goto(label);
1333 }
1334
1335 /**
1336 * Perform a comparison of two number types that are popped from the stack
1337 *
1338 * @param isCmpG is this a dcmpg semantic, false if it's a dcmpl semantic
1339 *
1340 * @return the method emitter
1341 */
1342 MethodEmitter cmp(final boolean isCmpG) {
1343 pushType(get2n().cmp(method, isCmpG));
1344 return this;
1345 }
1346
1347 /**
1348 * Helper function for jumps, conditional or not
1349 * @param opcode opcode for jump
1350 * @param label destination
1351 * @param n elements on stack to compare, 0-2
1352 */
1353 private void jump(final int opcode, final Label label, final int n) {
1354 for (int i = 0; i < n; i++) {
1355 assert peekType().isInteger() || peekType().isBoolean() || peekType().isObject() : "expecting integer type or object for jump, but found " + peekType();
1356 popType();
1357 }
1358 mergeStackTo(label);
1359 method.visitJumpInsn(opcode, label.getLabel());
1360 }
1361
1362 /**
1363 * Generate an if_acmpeq
1364 *
1365 * @param label label to true case
1366 */
1367 void if_acmpeq(final Label label) {
1368 debug("if_acmpeq", label);
1369 jump(IF_ACMPEQ, label, 2);
1370 }
1371
1372 /**
1373 * Generate an if_acmpne
1374 *
1375 * @param label label to true case
1376 */
1377 void if_acmpne(final Label label) {
1378 debug("if_acmpne", label);
1379 jump(IF_ACMPNE, label, 2);
1380 }
1381
1382 /**
1383 * Generate an ifnull
1384 *
1385 * @param label label to true case
1386 */
1387 void ifnull(final Label label) {
1388 debug("ifnull", label);
1389 jump(IFNULL, label, 1);
1390 }
1391
1392 /**
1393 * Generate an ifnonnull
1394 *
1395 * @param label label to true case
1396 */
1397 void ifnonnull(final Label label) {
1398 debug("ifnonnull", label);
1399 jump(IFNONNULL, label, 1);
1400 }
1401
1402 /**
1403 * Generate an ifeq
1404 *
1405 * @param label label to true case
1406 */
1407 void ifeq(final Label label) {
1408 debug("ifeq ", label);
1409 jump(IFEQ, label, 1);
1410 }
1411
1412 /**
1413 * Generate an if_icmpeq
1414 *
1415 * @param label label to true case
1416 */
1417 void if_icmpeq(final Label label) {
1418 debug("if_icmpeq", label);
1419 jump(IF_ICMPEQ, label, 2);
1420 }
1421
1422 /**
1423 * Generate an if_ne
1424 *
1425 * @param label label to true case
1426 */
1427 void ifne(final Label label) {
1428 debug("ifne", label);
1429 jump(IFNE, label, 1);
1430 }
1431
1432 /**
1433 * Generate an if_icmpne
1434 *
1435 * @param label label to true case
1436 */
1437 void if_icmpne(final Label label) {
1438 debug("if_icmpne", label);
1439 jump(IF_ICMPNE, label, 2);
1440 }
1441
1442 /**
1443 * Generate an iflt
1444 *
1445 * @param label label to true case
1446 */
1447 void iflt(final Label label) {
1448 debug("iflt", label);
1449 jump(IFLT, label, 1);
1450 }
1451
1452 /**
1453 * Generate an ifle
1454 *
1455 * @param label label to true case
1456 */
1457 void ifle(final Label label) {
1458 debug("ifle", label);
1459 jump(IFLE, label, 1);
1460 }
1461
1462 /**
1463 * Generate an ifgt
1464 *
1465 * @param label label to true case
1466 */
1467 void ifgt(final Label label) {
1468 debug("ifgt", label);
1469 jump(IFGT, label, 1);
1470 }
1471
1472 /**
1473 * Generate an ifge
1474 *
1475 * @param label label to true case
1476 */
1477 void ifge(final Label label) {
1478 debug("ifge", label);
1479 jump(IFGE, label, 1);
1480 }
1481
1482 /**
1483 * Unconditional jump to a label
1484 *
1485 * @param label destination label
1486 */
1487 void _goto(final Label label) {
1488 //debug("goto", label);
1489 jump(GOTO, label, 0);
1490 stack = null; //whoever reaches the point after us provides the stack, because we don't
1491 }
1492
1493 /**
1494 * Examine two stacks and make sure they are of the same size and their
1495 * contents are equivalent to each other
1496 * @param s0 first stack
1497 * @param s1 second stack
1498 *
1499 * @return true if stacks are equivalent, false otherwise
1500 */
1501 /**
1502 * A join in control flow - helper function that makes sure all entry stacks
1503 * discovered for the join point so far are equivalent
1504 *
1505 * MergeStack: we are about to enter a label. If its stack, label.getStack() is null
1506 * we have never been here before. Then we are expected to carry a stack with us.
1507 *
1508 * @param label label
1509 */
1510 private void mergeStackTo(final Label label) {
1511 //sometimes we can do a merge stack without having a stack - i.e. when jumping ahead to dead code
1512 //see NASHORN-73. So far we had been saved by the line number nodes. This should have been fixed
1513 //by Lower removing everything after an unconditionally executed terminating statement OR a break
1514 //or continue in a block. Previously code left over after breaks and continues was still there
1515 //and caused bytecode to be generated - which crashed on stack not being there, as the merge
1516 //was not in fact preceeded by a visit. Furthermore, this led to ASM putting out its NOP NOP NOP
1517 //ATHROW sequences instead of no code being generated at all. This should now be fixed.
1518 assert stack != null : label + " entered with no stack. deadcode that remains?";
1519
1520 final Label.Stack labelStack = label.getStack();
1521 if (labelStack == null) {
1522 label.setStack(stack.copy());
1523 return;
1524 }
1525 assert stack.isEquivalentTo(labelStack) : "stacks " + stack + " is not equivalent with " + labelStack + " at join point";
1526 }
1527
1528 /**
1529 * Register a new label, enter it here.
1530 *
1531 * @param label the label
1532 */
1533 void label(final Label label) {
1534 /*
1535 * If stack == null, this means that we came here not through a fallthrough.
1536 * E.g. a label after an athrow. Then we create a new stack if one doesn't exist
1537 * for this location already.
1538 */
1539 if (stack == null) {
1540 stack = label.getStack();
1541 if (stack == null) {
1542 newStack();
1543 }
1544 }
1545 debug_label(label);
1546
1547 mergeStackTo(label); //we have to merge our stack to whatever is in the label
1548
1549 method.visitLabel(label.getLabel());
1550 }
1551
1552 /**
1553 * Pop element from stack, convert to given type
1554 *
1555 * @param to type to convert to
1556 *
1557 * @return the method emitter
1558 */
1559 MethodEmitter convert(final Type to) {
1560 final Type type = peekType().convert(method, to);
1561 if (type != null) {
1562 if (!peekType().isEquivalentTo(to)) {
1563 debug("convert", peekType(), "->", to);
1564 }
1565 popType();
1566 pushType(type);
1567 }
1568 return this;
1569 }
1570
1571 /**
1572 * Helper function - expect two types that are equivalent
1573 *
1574 * @return common type
1575 */
1576 private Type get2() {
1577 final Type p0 = popType();
1578 final Type p1 = popType();
1579 assert p0.isEquivalentTo(p1) : "expecting equivalent types on stack but got " + p0 + " and " + p1;
1580 return p0;
1581 }
1582
1583 /**
1584 * Helper function - expect two types that are integer types and equivalent
1585 *
1586 * @return common type
1587 */
1588 private BitwiseType get2i() {
1589 final BitwiseType p0 = popInteger();
1590 final BitwiseType p1 = popInteger();
1591 assert p0.isEquivalentTo(p1) : "expecting equivalent types on stack but got " + p0 + " and " + p1;
1592 return p0;
1593 }
1594
1595 /**
1596 * Helper function - expect two types that are numbers and equivalent
1597 *
1598 * @return common type
1599 */
1600 private NumericType get2n() {
1601 final NumericType p0 = popNumeric();
1602 final NumericType p1 = popNumeric();
1603 assert p0.isEquivalentTo(p1) : "expecting equivalent types on stack but got " + p0 + " and " + p1;
1604 return p0;
1605 }
1606
1607 /**
1608 * Pop two numbers, perform addition and push result
1609 *
1610 * @return the method emitter
1611 */
1612 MethodEmitter add() {
1613 debug("add");
1614 pushType(get2().add(method));
1615 return this;
1616 }
1617
1618 /**
1619 * Pop two numbers, perform subtraction and push result
1620 *
1621 * @return the method emitter
1622 */
1623 MethodEmitter sub() {
1624 debug("sub");
1625 pushType(get2n().sub(method));
1626 return this;
1627 }
1628
1629 /**
1630 * Pop two numbers, perform multiplication and push result
1631 *
1632 * @return the method emitter
1633 */
1634 MethodEmitter mul() {
1635 debug("mul ");
1636 pushType(get2n().mul(method));
1637 return this;
1638 }
1639
1640 /**
1641 * Pop two numbers, perform division and push result
1642 *
1643 * @return the method emitter
1644 */
1645 MethodEmitter div() {
1646 debug("div");
1647 pushType(get2n().div(method));
1648 return this;
1649 }
1650
1651 /**
1652 * Pop two numbers, calculate remainder and push result
1653 *
1654 * @return the method emitter
1655 */
1656 MethodEmitter rem() {
1657 debug("rem");
1658 pushType(get2n().rem(method));
1659 return this;
1660 }
1661
1662 /**
1663 * Retrieve the top <tt>count</tt> types on the stack without modifying it.
1664 *
1665 * @param count number of types to return
1666 * @return array of Types
1667 */
1668 protected Type[] getTypesFromStack(final int count) {
1669 final Type[] types = new Type[count];
1670 int pos = 0;
1671 for (int i = count - 1; i >= 0; i--) {
1672 types[i] = stack.peek(pos++);
1673 }
1674
1675 return types;
1676 }
1677
1678 /**
1679 * Helper function to generate a function signature based on stack contents
1680 * and argument count and return type
1681 *
1682 * @param returnType return type
1683 * @param argCount argument count
1684 *
1685 * @return function signature for stack contents
1686 */
1687 private String getDynamicSignature(final Type returnType, final int argCount) {
1688 final Type[] paramTypes = new Type[argCount];
1689
1690 int pos = 0;
1691 for (int i = argCount - 1; i >= 0; i--) {
1692 paramTypes[i] = stack.peek(pos++);
1693 }
1694 final String descriptor = Type.getMethodDescriptor(returnType, paramTypes);
1695 for (int i = 0; i < argCount; i++) {
1696 popType(paramTypes[argCount - i - 1]);
1697 }
1698
1699 return descriptor;
1700 }
1701
1702 /**
1703 * Generate a dynamic new
1704 *
1705 * @param argCount number of arguments
1706 * @param flags callsite flags
1707 *
1708 * @return the method emitter
1709 */
1710 MethodEmitter dynamicNew(final int argCount, final int flags) {
1711 debug("dynamic_new", "argcount=", argCount);
1712 final String signature = getDynamicSignature(Type.OBJECT, argCount);
1713 method.visitInvokeDynamicInsn("dyn:new", signature, LINKERBOOTSTRAP, flags);
1714 pushType(Type.OBJECT); //TODO fix result type
1715 return this;
1716 }
1717
1718 /**
1719 * Generate a dynamic call
1720 *
1721 * @param returnType return type
1722 * @param argCount number of arguments
1723 * @param flags callsite flags
1724 *
1725 * @return the method emitter
1726 */
1727 MethodEmitter dynamicCall(final Type returnType, final int argCount, final int flags) {
1728 debug("dynamic_call", "args=", argCount, "returnType=", returnType);
1729 final String signature = getDynamicSignature(returnType, argCount); // +1 because the function itself is the 1st parameter for dynamic calls (what you call - call target)
1730 debug(" signature", signature);
1731 method.visitInvokeDynamicInsn("dyn:call", signature, LINKERBOOTSTRAP, flags);
1732 pushType(returnType);
1733
1734 return this;
1735 }
1736
1737 /**
1738 * Generate a dynamic call for a runtime node
1739 *
1740 * @param name tag for the invoke dynamic for this runtime node
1741 * @param returnType return type
1742 * @param request RuntimeNode request
1743 *
1744 * @return the method emitter
1745 */
1746 MethodEmitter dynamicRuntimeCall(final String name, final Type returnType, final RuntimeNode.Request request) {
1747 debug("dynamic_runtime_call", name, "args=", request.getArity(), "returnType=", returnType);
1748 final String signature = getDynamicSignature(returnType, request.getArity());
1749 debug(" signature", signature);
1750 method.visitInvokeDynamicInsn(name, signature, RUNTIMEBOOTSTRAP);
1751 pushType(returnType);
1752
1753 return this;
1754 }
1755
1756 /**
1757 * Generate dynamic getter. Pop scope from stack. Push result
1758 *
1759 * @param valueType type of the value to set
1760 * @param name name of property
1761 * @param flags call site flags
1762 * @param isMethod should it prefer retrieving methods
1763 *
1764 * @return the method emitter
1765 */
1766 MethodEmitter dynamicGet(final Type valueType, final String name, final int flags, final boolean isMethod) {
1767 debug("dynamic_get", name, valueType);
1768
1769 Type type = valueType;
1770 if (type.isObject() || type.isBoolean()) {
1771 type = Type.OBJECT; //promote e.g strings to object generic setter
1772 }
1773
1774 popType(Type.SCOPE);
1775 method.visitInvokeDynamicInsn((isMethod ? "dyn:getMethod|getProp|getElem:" : "dyn:getProp|getElem|getMethod:") +
1776 NameCodec.encode(name), Type.getMethodDescriptor(type, Type.OBJECT), LINKERBOOTSTRAP, flags);
1777
1778 pushType(type);
1779
1780 convert(valueType); //most probably a nop
1781
1782 return this;
1783 }
1784
1785 /**
1786 * Generate dynamic setter. Pop receiver and property from stack.
1787 *
1788 * @param valueType the type of the value to set
1789 * @param name name of property
1790 * @param flags call site flags
1791 */
1792 void dynamicSet(final String name, final int flags) {
1793 debug("dynamic_set", name, peekType());
1794
1795 Type type = peekType();
1796 if (type.isObject() || type.isBoolean()) { //promote strings to objects etc
1797 type = Type.OBJECT;
1798 convert(Type.OBJECT); //TODO bad- until we specialize boolean setters,
1799 }
1800 popType(type);
1801 popType(Type.SCOPE);
1802
1803 method.visitInvokeDynamicInsn("dyn:setProp|setElem:" + NameCodec.encode(name), methodDescriptor(void.class, Object.class, type.getTypeClass()), LINKERBOOTSTRAP, flags);
1804 }
1805
1806 /**
1807 * Dynamic getter for indexed structures. Pop index and receiver from stack,
1808 * generate appropriate signatures based on types
1809 *
1810 * @param result result type for getter
1811 * @param flags call site flags for getter
1812 * @param isMethod should it prefer retrieving methods
1813 *
1814 * @return the method emitter
1815 */
1816 MethodEmitter dynamicGetIndex(final Type result, final int flags, final boolean isMethod) {
1817 debug("dynamic_get_index", peekType(1), "[", peekType(), "]");
1818
1819 Type resultType = result;
1820 if (result.isBoolean()) {
1821 resultType = Type.OBJECT; // INT->OBJECT to avoid another dimension of cross products in the getters. TODO
1822 }
1823
1824 Type index = peekType();
1825 if (index.isObject() || index.isBoolean()) {
1826 index = Type.OBJECT; //e.g. string->object
1827 convert(Type.OBJECT);
1828 }
1829 popType();
1830
1831 popType(Type.OBJECT);
1832
1833 final String signature = Type.getMethodDescriptor(resultType, Type.OBJECT /*e.g STRING->OBJECT*/, index);
1834
1835 method.visitInvokeDynamicInsn(isMethod ? "dyn:getMethod|getElem|getProp" : "dyn:getElem|getProp|getMethod",
1836 signature, LINKERBOOTSTRAP, flags);
1837 pushType(resultType);
1838
1839 if (result.isBoolean()) {
1840 convert(Type.BOOLEAN);
1841 }
1842
1843 return this;
1844 }
1845
1846 /**
1847 * Dynamic setter for indexed structures. Pop value, index and receiver from
1848 * stack, generate appropriate signature based on types
1849 *
1850 * @param flags call site flags for setter
1851 */
1852 void dynamicSetIndex(final int flags) {
1853 debug("dynamic_set_index", peekType(2), "[", peekType(1), "] =", peekType());
1854
1855 Type value = peekType();
1856 if (value.isObject() || value.isBoolean()) {
1857 value = Type.OBJECT; //e.g. STRING->OBJECT - one descriptor for all object types
1858 convert(Type.OBJECT);
1859 }
1860 popType();
1861
1862 Type index = peekType();
1863 if (index.isObject() || index.isBoolean()) {
1864 index = Type.OBJECT; //e.g. string->object
1865 convert(Type.OBJECT);
1866 }
1867 popType(index);
1868
1869 final Type receiver = popType(Type.OBJECT);
1870 assert receiver.isObject();
1871
1872 method.visitInvokeDynamicInsn("dyn:setElem|setProp", methodDescriptor(void.class, receiver.getTypeClass(), index.getTypeClass(), value.getTypeClass()), LINKERBOOTSTRAP, flags);
1873 }
1874
1875 /**
1876 * Load a key value in the proper form.
1877 *
1878 * @param key
1879 */
1880 //TODO move this and break it apart
1881 MethodEmitter loadKey(final Object key) {
1882 if (key instanceof IdentNode) {
1883 method.visitLdcInsn(((IdentNode) key).getName());
1884 } else if (key instanceof LiteralNode) {
1885 method.visitLdcInsn(((LiteralNode<?>)key).getString());
1886 } else {
1887 method.visitLdcInsn(JSType.toString(key));
1888 }
1889 pushType(Type.OBJECT); //STRING
1890 return this;
1891 }
1892
1893 @SuppressWarnings("fallthrough")
1894 private static Type fieldType(final String desc) {
1895 switch (desc) {
1896 case "Z":
1897 case "B":
1898 case "C":
1899 case "S":
1900 case "I":
1901 return Type.INT;
1902 case "F":
1903 assert false;
1904 case "D":
1905 return Type.NUMBER;
1906 case "J":
1907 return Type.LONG;
1908 default:
1909 assert desc.startsWith("[") || desc.startsWith("L") : desc + " is not an object type";
1910 switch (desc.charAt(0)) {
1911 case 'L':
1912 return Type.OBJECT;
1913 case '[':
1914 return Type.typeFor(Array.newInstance(fieldType(desc.substring(1)).getTypeClass(), 0).getClass());
1915 default:
1916 assert false;
1917 }
1918 return Type.OBJECT;
1919 }
1920 }
1921
1922 /**
1923 * Generate get for a field access
1924 *
1925 * @param fa the field access
1926 *
1927 * @return the method emitter
1928 */
1929 MethodEmitter getField(final FieldAccess fa) {
1930 return fa.get(this);
1931 }
1932
1933 /**
1934 * Generate set for a field access
1935 *
1936 * @param fa the field access
1937 */
1938 void putField(final FieldAccess fa) {
1939 fa.put(this);
1940 }
1941
1942 /**
1943 * Get the value of a non-static field, pop the receiver from the stack,
1944 * push value to the stack
1945 *
1946 * @param className class
1947 * @param fieldName field name
1948 * @param fieldDescriptor field descriptor
1949 *
1950 * @return the method emitter
1951 */
1952 MethodEmitter getField(final String className, final String fieldName, final String fieldDescriptor) {
1953 debug("getfield", "receiver=", peekType(), className, ".", fieldName, fieldDescriptor);
1954 final Type receiver = popType();
1955 assert receiver.isObject();
1956 method.visitFieldInsn(GETFIELD, className, fieldName, fieldDescriptor);
1957 pushType(fieldType(fieldDescriptor));
1958 return this;
1959 }
1960
1961 /**
1962 * Get the value of a static field, push it to the stack
1963 *
1964 * @param className class
1965 * @param fieldName field name
1966 * @param fieldDescriptor field descriptor
1967 *
1968 * @return the method emitter
1969 */
1970 MethodEmitter getStatic(final String className, final String fieldName, final String fieldDescriptor) {
1971 debug("getstatic", className, ".", fieldName, ".", fieldDescriptor);
1972 method.visitFieldInsn(GETSTATIC, className, fieldName, fieldDescriptor);
1973 pushType(fieldType(fieldDescriptor));
1974 return this;
1975 }
1976
1977 /**
1978 * Pop value and field from stack and write to a non-static field
1979 *
1980 * @param className class
1981 * @param fieldName field name
1982 * @param fieldDescriptor field descriptor
1983 */
1984 void putField(final String className, final String fieldName, final String fieldDescriptor) {
1985 debug("putfield", "receiver=", peekType(1), "value=", peekType());
1986 popType(fieldType(fieldDescriptor));
1987 popType(Type.OBJECT);
1988 method.visitFieldInsn(PUTFIELD, className, fieldName, fieldDescriptor);
1989 }
1990
1991 /**
1992 * Pop value from stack and write to a static field
1993 *
1994 * @param className class
1995 * @param fieldName field name
1996 * @param fieldDescriptor field descriptor
1997 */
1998 void putStatic(final String className, final String fieldName, final String fieldDescriptor) {
1999 debug("putfield", "value=", peekType());
2000 popType(fieldType(fieldDescriptor));
2001 method.visitFieldInsn(PUTSTATIC, className, fieldName, fieldDescriptor);
2002 }
2003
2004 /**
2005 * Register line number at a label
2006 *
2007 * @param line line number
2008 * @param label label
2009 */
2010 void lineNumber(final int line) {
2011 if (env._debug_lines) {
2012 debug_label("[LINE]", line);
2013 final jdk.internal.org.objectweb.asm.Label l = new jdk.internal.org.objectweb.asm.Label();
2014 method.visitLabel(l);
2015 method.visitLineNumber(line, l);
2016 }
2017 }
2018
2019 /*
2020 * Debugging below
2021 */
2022
2023 private final FieldAccess ERR_STREAM = staticField(System.class, "err", PrintStream.class);
2024 private final Call PRINT = virtualCallNoLookup(PrintStream.class, "print", void.class, Object.class);
2025 private final Call PRINTLN = virtualCallNoLookup(PrintStream.class, "println", void.class, Object.class);
2026 private final Call PRINT_STACKTRACE = virtualCallNoLookup(Throwable.class, "printStackTrace", void.class);
2027
2028 /**
2029 * Emit a System.err.print statement of whatever is on top of the bytecode stack
2030 */
2031 void print() {
2032 getField(ERR_STREAM);
2033 swap();
2034 convert(Type.OBJECT);
2035 invoke(PRINT);
2036 }
2037
2038 /**
2039 * Emit a System.err.println statement of whatever is on top of the bytecode stack
2040 */
2041 void println() {
2042 getField(ERR_STREAM);
2043 swap();
2044 convert(Type.OBJECT);
2045 invoke(PRINTLN);
2046 }
2047
2048 /**
2049 * Emit a System.err.print statement
2050 * @param string string to print
2051 */
2052 void print(final String string) {
2053 getField(ERR_STREAM);
2054 load(string);
2055 invoke(PRINT);
2056 }
2057
2058 /**
2059 * Emit a System.err.println statement
2060 * @param string string to print
2061 */
2062 void println(final String string) {
2063 getField(ERR_STREAM);
2064 load(string);
2065 invoke(PRINTLN);
2066 }
2067
2068 /**
2069 * Print a stacktrace to S
2070 */
2071 void stacktrace() {
2072 _new(Throwable.class);
2073 dup();
2074 invoke(constructorNoLookup(Throwable.class));
2075 invoke(PRINT_STACKTRACE);
2076 }
2077
2078 private static int linePrefix = 0;
2079
2080 /**
2081 * Debug function that outputs generated bytecode and stack contents
2082 *
2083 * @param args debug information to print
2084 */
2085 private void debug(final Object... args) {
2086 if (DEBUG) {
2087 debug(30, args);
2088 }
2089 }
2090
2091 /**
2092 * Debug function that outputs generated bytecode and stack contents
2093 * for a label - indentation is currently the only thing that differs
2094 *
2095 * @param args debug information to print
2096 */
2097 private void debug_label(final Object... args) {
2098 if (DEBUG) {
2099 debug(22, args);
2100 }
2101 }
2102
2103 private void debug(final int padConstant, final Object... args) {
2104 if (DEBUG) {
2105 final StringBuilder sb = new StringBuilder();
2106 int pad;
2107
2108 sb.append('#');
2109 sb.append(++linePrefix);
2110
2111 pad = 5 - sb.length();
2112 while (pad > 0) {
2113 sb.append(' ');
2114 pad--;
2115 }
2116
2117 if (stack != null && !stack.isEmpty()) {
2118 sb.append("{");
2119 sb.append(stack.size());
2120 sb.append(":");
2121 for (int pos = 0; pos < stack.size(); pos++) {
2122 final Type t = stack.peek(pos);
2123
2124 if (t == Type.SCOPE) {
2125 sb.append("scope");
2126 } else if (t == Type.THIS) {
2127 sb.append("this");
2128 } else if (t.isObject()) {
2129 String desc = t.getDescriptor();
2130 int i;
2131 for (i = 0; desc.charAt(i) == '[' && i < desc.length(); i++) {
2132 sb.append('[');
2133 }
2134 desc = desc.substring(i);
2135 final int slash = desc.lastIndexOf('/');
2136 if (slash != -1) {
2137 desc = desc.substring(slash + 1, desc.length() - 1);
2138 }
2139 if ("Object".equals(desc)) {
2140 sb.append('O');
2141 } else {
2142 sb.append(desc);
2143 }
2144 } else {
2145 sb.append(t.getDescriptor());
2146 }
2147
2148 if (pos + 1 < stack.size()) {
2149 sb.append(' ');
2150 }
2151 }
2152 sb.append('}');
2153 sb.append(' ');
2154 }
2155
2156 pad = padConstant - sb.length();
2157 while (pad > 0) {
2158 sb.append(' ');
2159 pad--;
2160 }
2161
2162 for (final Object arg : args) {
2163 sb.append(arg);
2164 sb.append(' ');
2165 }
2166
2167 if (env != null) { //early bootstrap code doesn't have inited context yet
2168 LOG.info(sb);
2169 if (DEBUG_TRACE_LINE == linePrefix) {
2170 new Throwable().printStackTrace(LOG.getOutputStream());
2171 }
2172 }
2173 }
2174 }
2175
2176 /**
2177 * Set the current function node being emitted
2178 * @param functionNode the function node
2179 */
2180 void setFunctionNode(final FunctionNode functionNode) {
2181 this.functionNode = functionNode;
2182 }
2183
2184 boolean hasReturn() {
2185 return hasReturn;
2186 }
2187
2188 List<Label> getExternalTargets() {
2189 return null;
2190 }
2191
2192 }