7 ////////////////////////////////////////////////////////////////////////
8 // Debugging stuff. ////////////////////////////////////////////////////
9 ////////////////////////////////////////////////////////////////////////
10 //#define INTERPRETER_DUMP
11 #if !defined(INTERPRETER_DUMP)
12 # define DBG(expr) /* noop */
14 # define DBG(expr) expr
18 char* opStringDEBUG(int op);
19 void printOpDEBUG(int ip, int op);
20 void printStackDEBUG(naContext ctx);
21 ////////////////////////////////////////////////////////////////////////
24 #define vsnprintf _vsnprintf
27 struct Globals* globals = 0;
29 static naRef bindFunction(naContext ctx, struct Frame* f, naRef code);
31 #define ERR(c, msg) naRuntimeError((c),(msg))
32 void naRuntimeError(naContext c, const char* fmt, ...)
36 vsnprintf(c->error, sizeof(c->error), fmt, ap);
38 longjmp(c->jumpHandle, 1);
41 void naRethrowError(naContext subc)
43 strncpy(subc->callParent->error, subc->error, sizeof(subc->error));
44 subc->callParent->dieArg = subc->dieArg;
45 longjmp(subc->callParent->jumpHandle, 1);
48 #define END_PTR ((void*)1)
49 #define IS_END(r) (IS_REF((r)) && PTR((r)).obj == END_PTR)
50 static naRef endToken()
57 static int boolify(naContext ctx, naRef r)
59 if(IS_NUM(r)) return r.num != 0;
60 if(IS_NIL(r) || IS_END(r)) return 0;
63 if(naStr_len(r) == 0) return 0;
64 if(naStr_tonum(r, &d)) return d != 0;
67 ERR(ctx, "non-scalar used in boolean context");
71 static double numify(naContext ctx, naRef o)
74 if(IS_NUM(o)) return o.num;
75 else if(IS_NIL(o)) ERR(ctx, "nil used in numeric context");
76 else if(!IS_STR(o)) ERR(ctx, "non-scalar in numeric context");
77 else if(naStr_tonum(o, &n)) return n;
78 else ERR(ctx, "non-numeric string in numeric context");
82 static naRef stringify(naContext ctx, naRef r)
84 if(IS_STR(r)) return r;
85 if(IS_NUM(r)) return naStr_fromnum(naNewString(ctx), r.num);
86 ERR(ctx, "non-scalar in string context");
90 static int checkVec(naContext ctx, naRef vec, naRef idx)
92 int i = (int)numify(ctx, idx);
93 if(i < 0) i += naVec_size(vec);
94 if(i < 0 || i >= naVec_size(vec))
95 naRuntimeError(ctx, "vector index %d out of bounds (size: %d)",
100 static int checkStr(naContext ctx, naRef str, naRef idx)
102 int i = (int)numify(ctx, idx);
103 if(i < 0) i += naStr_len(str);
104 if(i < 0 || i >= naStr_len(str))
105 naRuntimeError(ctx, "string index %d out of bounds (size: %d)",
110 static naRef containerGet(naContext ctx, naRef box, naRef key)
112 naRef result = naNil();
113 if(!IS_SCALAR(key)) ERR(ctx, "container index not scalar");
115 naHash_get(box, key, &result);
117 result = naVec_get(box, checkVec(ctx, box, key));
119 result = naNum((unsigned char)naStr_data(box)[checkStr(ctx, box, key)]);
121 ERR(ctx, "extract from non-container");
125 static void containerSet(naContext ctx, naRef box, naRef key, naRef val)
127 if(!IS_SCALAR(key)) ERR(ctx, "container index not scalar");
128 else if(IS_HASH(box)) naHash_set(box, key, val);
129 else if(IS_VEC(box)) naVec_set(box, checkVec(ctx, box, key), val);
130 else if(IS_STR(box)) {
131 if(PTR(box).str->hashcode)
132 ERR(ctx, "cannot change immutable string");
133 naStr_data(box)[checkStr(ctx, box, key)] = (char)numify(ctx, val);
134 } else ERR(ctx, "insert into non-container");
137 static void initTemps(naContext c)
140 c->temps = naAlloc(c->tempsz * sizeof(struct naObj*));
144 static void initContext(naContext c)
147 c->fTop = c->opTop = c->markTop = 0;
148 for(i=0; i<NUM_NASAL_TYPES; i++)
163 static void initGlobals()
167 globals = (struct Globals*)naAlloc(sizeof(struct Globals));
168 naBZero(globals, sizeof(struct Globals));
170 globals->sem = naNewSem();
171 globals->lock = naNewLock();
173 globals->allocCount = 256; // reasonable starting value
174 for(i=0; i<NUM_NASAL_TYPES; i++)
175 naGC_init(&(globals->pools[i]), i);
176 globals->deadsz = 256;
178 globals->deadBlocks = naAlloc(sizeof(void*) * globals->deadsz);
180 // Initialize a single context
181 globals->freeContexts = 0;
182 globals->allContexts = 0;
185 globals->symbols = naNewHash(c);
186 globals->save = naNewVector(c);
188 // Cache pre-calculated "me", "arg" and "parents" scalars
189 globals->meRef = naInternSymbol(naStr_fromdata(naNewString(c), "me", 2));
190 globals->argRef = naInternSymbol(naStr_fromdata(naNewString(c), "arg", 3));
191 globals->parentsRef = naInternSymbol(naStr_fromdata(naNewString(c), "parents", 7));
196 naContext naNewContext()
203 c = globals->freeContexts;
205 globals->freeContexts = c->nextFree;
211 c = (naContext)naAlloc(sizeof(struct Context));
215 c->nextAll = globals->allContexts;
217 globals->allContexts = c;
223 naContext naSubContext(naContext super)
225 naContext ctx = naNewContext();
226 if(super->callChild) naFreeContext(super->callChild);
227 ctx->callParent = super;
228 super->callChild = ctx;
232 void naFreeContext(naContext c)
235 if(c->callChild) naFreeContext(c->callChild);
236 if(c->callParent) c->callParent->callChild = 0;
238 c->nextFree = globals->freeContexts;
239 globals->freeContexts = c;
243 // Note that opTop is incremented separately, to avoid situations
244 // where the "r" expression also references opTop. The SGI compiler
245 // is known to have issues with such code.
246 #define PUSH(r) do { \
247 if(ctx->opTop >= MAX_STACK_DEPTH) ERR(ctx, "stack overflow"); \
248 ctx->opStack[ctx->opTop] = r; \
252 static void setupArgs(naContext ctx, struct Frame* f, naRef* args, int nargs)
255 struct naCode* c = PTR(PTR(f->func).func->code).code;
257 // Set the argument symbols, and put any remaining args in a vector
259 naRuntimeError(ctx, "too few function args (have %d need %d)",
261 for(i=0; i<c->nArgs; i++)
262 naiHash_newsym(PTR(f->locals).hash,
263 &c->constants[ARGSYMS(c)[i]], &args[i]);
266 for(i=0; i<c->nOptArgs; i++, nargs--) {
267 naRef val = nargs > 0 ? args[i] : c->constants[OPTARGVALS(c)[i]];
269 val = bindFunction(ctx, &ctx->fStack[ctx->fTop-2], val);
270 naiHash_newsym(PTR(f->locals).hash, &c->constants[OPTARGSYMS(c)[i]],
274 if(c->needArgVector || nargs > 0) {
275 naRef argv = naNewVector(ctx);
276 naVec_setsize(argv, nargs > 0 ? nargs : 0);
277 for(i=0; i<nargs; i++)
278 PTR(argv).vec->rec->array[i] = *args++;
279 naiHash_newsym(PTR(f->locals).hash, &c->constants[c->restArgSym], &argv);
283 static void checkNamedArgs(naContext ctx, struct naCode* c, struct naHash* h)
286 naRef sym, rest, dummy;
287 for(i=0; i<c->nArgs; i++) {
288 sym = c->constants[ARGSYMS(c)[i]];
289 if(!naiHash_sym(h, PTR(sym).str, &dummy))
290 naRuntimeError(ctx, "Missing arg: %s", naStr_data(sym));
292 for(i=0; i<c->nOptArgs; i++) {
293 sym = c->constants[OPTARGSYMS(c)[i]];
294 if(!naiHash_sym(h, PTR(sym).str, &dummy))
295 naiHash_newsym(h, &sym, &c->constants[OPTARGVALS(c)[i]]);
297 if(c->needArgVector) {
298 sym = c->constants[c->restArgSym];
299 if(!naiHash_sym(h, PTR(sym).str, &dummy)) {
300 rest = naNewVector(ctx);
301 naiHash_newsym(h, &sym, &rest);
306 static struct Frame* setupFuncall(naContext ctx, int nargs, int mcall, int named)
308 naRef *args, func, code, obj = naNil();
310 int opf = ctx->opTop - nargs;
312 args = &ctx->opStack[opf];
313 func = ctx->opStack[--opf];
314 if(!IS_FUNC(func)) ERR(ctx, "function/method call on uncallable object");
315 code = PTR(func).func->code;
316 if(mcall) obj = ctx->opStack[--opf];
320 naRef result = (*PTR(code).ccode->fptr)(ctx, obj, nargs, args);
321 if(named) ERR(ctx, "native functions have no named arguments");
322 ctx->opTop = ctx->opFrame;
324 return &(ctx->fStack[ctx->fTop-1]);
327 if(ctx->fTop >= MAX_RECURSION) ERR(ctx, "call stack overflow");
329 f = &(ctx->fStack[ctx->fTop]);
330 f->locals = named ? args[0] : naNewHash(ctx);
333 f->bp = ctx->opFrame;
335 if(mcall) naHash_set(f->locals, globals->meRef, obj);
337 if(named) checkNamedArgs(ctx, PTR(code).code, PTR(f->locals).hash);
338 else setupArgs(ctx, f, args, nargs);
341 ctx->opTop = f->bp; /* Pop the stack last, to avoid GC lossage */
345 static naRef evalEquality(int op, naRef ra, naRef rb)
347 int result = naEqual(ra, rb);
348 return naNum((op==OP_EQ) ? result : !result);
351 static naRef evalCat(naContext ctx, naRef l, naRef r)
353 if(IS_VEC(l) && IS_VEC(r)) {
354 int i, ls = naVec_size(l), rs = naVec_size(r);
355 naRef v = naNewVector(ctx);
356 naVec_setsize(v, ls + rs);
357 for(i=0; i<ls; i+=1) naVec_set(v, i, naVec_get(l, i));
358 for(i=0; i<rs; i+=1) naVec_set(v, i+ls, naVec_get(r, i));
361 naRef a = stringify(ctx, l);
362 naRef b = stringify(ctx, r);
363 return naStr_concat(naNewString(ctx), a, b);
367 // When a code object comes out of the constant pool and shows up on
368 // the stack, it needs to be bound with the lexical context.
369 static naRef bindFunction(naContext ctx, struct Frame* f, naRef code)
371 naRef result = naNewFunc(ctx, code);
372 PTR(result).func->namespace = f->locals;
373 PTR(result).func->next = f->func;
377 static int getClosure(struct naFunc* c, naRef sym, naRef* result)
380 if(naHash_get(c->namespace, sym, result)) return 1;
381 c = PTR(c->next).func;
386 static naRef getLocal2(naContext ctx, struct Frame* f, naRef sym)
389 if(!naHash_get(f->locals, sym, &result))
390 if(!getClosure(PTR(f->func).func, sym, &result))
391 naRuntimeError(ctx, "undefined symbol: %s", naStr_data(sym));
395 static void getLocal(naContext ctx, struct Frame* f, naRef* sym, naRef* out)
398 struct naStr* str = PTR(*sym).str;
399 if(naiHash_sym(PTR(f->locals).hash, str, out))
401 func = PTR(f->func).func;
402 while(func && PTR(func->namespace).hash) {
403 if(naiHash_sym(PTR(func->namespace).hash, str, out))
405 func = PTR(func->next).func;
407 // Now do it again using the more general naHash_get(). This will
408 // only be necessary if something has created the value in the
409 // namespace using the more generic hash syntax
410 // (e.g. namespace["symbol"] and not namespace.symbol).
411 *out = getLocal2(ctx, f, *sym);
414 static int setClosure(naRef func, naRef sym, naRef val)
416 struct naFunc* c = PTR(func).func;
418 if(naiHash_tryset(c->namespace, sym, val)) return 1;
419 return setClosure(c->next, sym, val);
422 static void setSymbol(struct Frame* f, naRef sym, naRef val)
424 // Try the locals first, if not already there try the closures in
425 // order. Finally put it in the locals if nothing matched.
426 if(!naiHash_tryset(f->locals, sym, val))
427 if(!setClosure(f->func, sym, val))
428 naHash_set(f->locals, sym, val);
431 // Funky API: returns null to indicate no member, an empty string to
432 // indicate success, or a non-empty error message. Works this way so
433 // we can generate smart error messages without throwing them with a
434 // longjmp -- this gets called under naMember_get() from C code.
435 static const char* getMember_r(naRef obj, naRef field, naRef* out, int count)
440 if(--count < 0) return "too many parents";
441 if(!IS_HASH(obj)) return "non-objects have no members";
442 if(naHash_get(obj, field, out)) return "";
443 if(!naHash_get(obj, globals->parentsRef, &p)) return 0;
444 if(!IS_VEC(p)) return "object \"parents\" field not vector";
445 pv = PTR(p).vec->rec;
446 for(i=0; pv && i<pv->size; i++) {
447 const char* err = getMember_r(pv->array[i], field, out, count);
448 if(err) return err; /* either an error or success */
453 static void getMember(naContext ctx, naRef obj, naRef fld,
454 naRef* result, int count)
456 const char* err = getMember_r(obj, fld, result, count);
457 if(!err) naRuntimeError(ctx, "No such member: %s", naStr_data(fld));
458 if(err[0]) naRuntimeError(ctx, err);
461 int naMember_get(naRef obj, naRef field, naRef* out)
463 const char* err = getMember_r(obj, field, out, 64);
464 return err && !err[0];
467 // OP_EACH works like a vector get, except that it leaves the vector
468 // and index on the stack, increments the index after use, and
469 // pushes a nil if the index is beyond the end.
470 static void evalEach(naContext ctx, int useIndex)
472 int idx = (int)(ctx->opStack[ctx->opTop-1].num);
473 naRef vec = ctx->opStack[ctx->opTop-2];
474 if(!IS_VEC(vec)) ERR(ctx, "foreach enumeration of non-vector");
475 if(!PTR(vec).vec->rec || idx >= PTR(vec).vec->rec->size) {
479 ctx->opStack[ctx->opTop-1].num = idx+1; // modify in place
480 PUSH(useIndex ? naNum(idx) : naVec_get(vec, idx));
483 static void evalUnpack(naContext ctx, int count)
485 naRef vec = ctx->opStack[--ctx->opTop];
486 if(!IS_VEC(vec) || naVec_size(vec) < count)
487 ERR(ctx, "short or invalid multi-assignment vector");
488 while(count--) PUSH(naVec_get(vec, count));
491 // FIXME: unify with almost identical checkVec() above
492 static int vbound(naContext ctx, naRef v, naRef ir, int end)
494 int sz=naVec_size(v), i = IS_NIL(ir) ? (end ? -1 : 0) : numify(ctx, ir);
495 if(IS_NIL(ir) && !sz) return i;
498 naRuntimeError(ctx, "slice index %d out of bounds (size: %d)",
503 static void evalSlice(naContext ctx, naRef src, naRef dst, naRef idx)
505 if(!IS_VEC(src)) ERR(ctx, "cannot slice non-vector");
506 naVec_append(dst, naVec_get(src, checkVec(ctx, src, idx)));
509 static void evalSlice2(naContext ctx, naRef src, naRef dst,
510 naRef start, naRef endr)
513 if(!IS_VEC(src)) ERR(ctx, "cannot slice non-vector");
514 end = vbound(ctx, src, endr, 1);
515 for(i = vbound(ctx, src, start, 0); i<=end; i++)
516 naVec_append(dst, naVec_get(src, i));
519 #define ARG() BYTECODE(cd)[f->ip++]
520 #define CONSTARG() cd->constants[ARG()]
521 #define POP() ctx->opStack[--ctx->opTop]
522 #define STK(n) (ctx->opStack[ctx->opTop-(n)])
523 #define SETFRAME(F) f = (F); cd = PTR(PTR(f->func).func->code).code;
524 #define FIXFRAME() SETFRAME(&(ctx->fStack[ctx->fTop-1]))
525 static naRef run(naContext ctx)
532 ctx->dieArg = naNil();
538 op = BYTECODE(cd)[f->ip++];
539 DBG(printf("Stack Depth: %d\n", ctx->opTop));
540 DBG(printOpDEBUG(f->ip-1, op));
542 case OP_POP: ctx->opTop--; break;
543 case OP_DUP: PUSH(STK(1)); break;
544 case OP_DUP2: PUSH(STK(2)); PUSH(STK(2)); break;
545 case OP_XCHG: a=STK(1); STK(1)=STK(2); STK(2)=a; break;
546 case OP_XCHG2: a=STK(1); STK(1)=STK(2); STK(2)=STK(3); STK(3)=a; break;
548 #define BINOP(expr) do { \
549 double l = IS_NUM(STK(2)) ? STK(2).num : numify(ctx, STK(2)); \
550 double r = IS_NUM(STK(1)) ? STK(1).num : numify(ctx, STK(1)); \
551 SETNUM(STK(2), expr); \
552 ctx->opTop--; } while(0)
554 case OP_PLUS: BINOP(l + r); break;
555 case OP_MINUS: BINOP(l - r); break;
556 case OP_MUL: BINOP(l * r); break;
557 case OP_DIV: BINOP(l / r); break;
558 case OP_LT: BINOP(l < r ? 1 : 0); break;
559 case OP_LTE: BINOP(l <= r ? 1 : 0); break;
560 case OP_GT: BINOP(l > r ? 1 : 0); break;
561 case OP_GTE: BINOP(l >= r ? 1 : 0); break;
564 case OP_EQ: case OP_NEQ:
565 STK(2) = evalEquality(op, STK(2), STK(1));
569 STK(2) = evalCat(ctx, STK(2), STK(1));
573 STK(1) = naNum(-numify(ctx, STK(1)));
576 STK(1) = naNum(boolify(ctx, STK(1)) ? 0 : 1);
580 if(IS_CODE(a)) a = bindFunction(ctx, f, a);
596 PUSH(naNewVector(ctx));
599 naVec_append(STK(2), STK(1));
603 PUSH(naNewHash(ctx));
606 naHash_set(STK(3), STK(2), STK(1));
611 getLocal(ctx, f, &a, &b);
615 setSymbol(f, STK(1), STK(2));
619 naHash_set(f->locals, STK(1), STK(2));
623 getMember(ctx, STK(1), CONSTARG(), &STK(1), 64);
626 if(!IS_HASH(STK(2))) ERR(ctx, "non-objects have no members");
627 naHash_set(STK(2), STK(1), STK(3));
631 containerSet(ctx, STK(2), STK(1), STK(3));
635 STK(2) = containerGet(ctx, STK(2), STK(1));
639 evalSlice(ctx, STK(3), STK(2), STK(1));
643 evalSlice2(ctx, STK(4), STK(3), STK(2), STK(1));
647 // Identical to JMP, except for locking
649 f->ip = BYTECODE(cd)[f->ip];
650 DBG(printf(" [Jump to: %d]\n", f->ip));
653 f->ip = BYTECODE(cd)[f->ip];
654 DBG(printf(" [Jump to: %d]\n", f->ip));
659 ctx->opTop--; // Pops **ONLY** if it's nil!
661 DBG(printf(" [Jump to: %d]\n", f->ip));
666 if(boolify(ctx, STK(1))) {
668 DBG(printf(" [Jump to: %d]\n", f->ip));
673 if(!boolify(ctx, STK(1))) {
675 DBG(printf(" [Jump to: %d]\n", f->ip));
680 if(!boolify(ctx, POP())) {
682 DBG(printf(" [Jump to: %d]\n", f->ip));
685 case OP_FCALL: SETFRAME(setupFuncall(ctx, ARG(), 0, 0)); break;
686 case OP_MCALL: SETFRAME(setupFuncall(ctx, ARG(), 1, 0)); break;
687 case OP_FCALLH: SETFRAME(setupFuncall(ctx, 1, 0, 1)); break;
688 case OP_MCALLH: SETFRAME(setupFuncall(ctx, 1, 1, 1)); break;
691 ctx->dieArg = naNil();
692 if(ctx->callChild) naFreeContext(ctx->callChild);
693 if(--ctx->fTop <= 0) return a;
694 ctx->opTop = f->bp + 1; // restore the correct opstack frame!
704 case OP_MARK: // save stack state (e.g. "setjmp")
705 if(ctx->markTop >= MAX_MARK_DEPTH)
706 ERR(ctx, "mark stack overflow");
707 ctx->markStack[ctx->markTop++] = ctx->opTop;
709 case OP_UNMARK: // pop stack state set by mark
712 case OP_BREAK: // restore stack state (FOLLOW WITH JMP!)
713 ctx->opTop = ctx->markStack[ctx->markTop-1];
715 case OP_BREAK2: // same, but also pop the mark stack
716 ctx->opTop = ctx->markStack[--ctx->markTop];
719 evalUnpack(ctx, ARG());
722 ERR(ctx, "BUG: bad opcode");
724 ctx->ntemps = 0; // reset GC temp vector
725 DBG(printStackDEBUG(ctx));
727 return naNil(); // unreachable
734 void naSave(naContext ctx, naRef obj)
736 naVec_append(globals->save, obj);
739 int naStackDepth(naContext ctx)
741 return ctx ? ctx->fTop + naStackDepth(ctx->callChild): 0;
744 static int findFrame(naContext ctx, naContext* out, int fn)
746 int sd = naStackDepth(ctx->callChild);
747 if(fn < sd) return findFrame(ctx->callChild, out, fn);
749 return ctx->fTop - 1 - (fn - sd);
752 int naGetLine(naContext ctx, int frame)
755 frame = findFrame(ctx, &ctx, frame);
756 f = &ctx->fStack[frame];
757 if(IS_FUNC(f->func) && IS_CODE(PTR(f->func).func->code)) {
758 struct naCode* c = PTR(PTR(f->func).func->code).code;
759 unsigned short* p = LINEIPS(c) + c->nLines - 2;
760 while(p >= LINEIPS(c) && p[0] > f->ip)
767 naRef naGetSourceFile(naContext ctx, int frame)
770 frame = findFrame(ctx, &ctx, frame);
771 f = ctx->fStack[frame].func;
772 f = PTR(f).func->code;
773 return PTR(f).code->srcFile;
776 char* naGetError(naContext ctx)
778 if(IS_STR(ctx->dieArg))
779 return naStr_data(ctx->dieArg);
780 return ctx->error[0] ? ctx->error : 0;
783 naRef naBindFunction(naContext ctx, naRef code, naRef closure)
785 naRef func = naNewFunc(ctx, code);
786 PTR(func).func->namespace = closure;
787 PTR(func).func->next = naNil();
791 naRef naBindToContext(naContext ctx, naRef code)
793 naRef func = naNewFunc(ctx, code);
795 struct Frame* f = &ctx->fStack[ctx->fTop-1];
796 PTR(func).func->namespace = f->locals;
797 PTR(func).func->next = f->func;
802 naRef naCall(naContext ctx, naRef func, int argc, naRef* args,
803 naRef obj, naRef locals)
807 if(!ctx->callParent) naModLock();
809 // We might have to allocate objects, which can call the GC. But
810 // the call isn't on the Nasal stack yet, so the GC won't find our
811 // C-space arguments.
812 naTempSave(ctx, func);
813 for(i=0; i<argc; i++)
814 naTempSave(ctx, args[i]);
815 naTempSave(ctx, obj);
816 naTempSave(ctx, locals);
818 // naRuntimeError() calls end up here:
819 if(setjmp(ctx->jumpHandle)) {
820 if(!ctx->callParent) naModUnlock();
824 if(IS_CCODE(PTR(func).func->code)) {
825 naCFunction fp = PTR(PTR(func).func->code).ccode->fptr;
826 result = (*fp)(ctx, obj, argc, args);
827 if(!ctx->callParent) naModUnlock();
832 locals = naNewHash(ctx);
834 func = naNewFunc(ctx, func);
835 PTR(func).func->namespace = locals;
838 naHash_set(locals, globals->meRef, obj);
840 ctx->opTop = ctx->markTop = 0;
842 ctx->fStack[0].func = func;
844 ctx->fStack[0].locals = locals;
845 ctx->fStack[0].ip = 0;
846 ctx->fStack[0].bp = ctx->opTop;
848 setupArgs(ctx, ctx->fStack, args, argc);
851 if(!ctx->callParent) naModUnlock();
855 naRef naContinue(naContext ctx)
858 if(!ctx->callParent) naModLock();
860 ctx->dieArg = naNil();
863 if(setjmp(ctx->jumpHandle)) {
864 if(!ctx->callParent) naModUnlock();
865 else naRethrowError(ctx);
869 // Wipe off the old function arguments, and push the expected
870 // result (either the result of our subcontext, or a synthesized
871 // nil if the thrown error was from an extension function or
872 // in-script die() call) before re-running the code from the
873 // instruction following the error.
874 ctx->opTop = ctx->opFrame;
875 PUSH(ctx->callChild ? naContinue(ctx->callChild) : naNil());
877 // Getting here means the child completed successfully. But
878 // because its original C stack was longjmp'd out of existence,
879 // there is no one left to free the context, so we have to do it.
880 // This is fragile, but unfortunately required.
881 if(ctx->callChild) naFreeContext(ctx->callChild);
884 if(!ctx->callParent) naModUnlock();