Line | Branch | Decision | Exec | Source |
---|---|---|---|---|
1 | /* | |||
2 | ** $Id: ldo.c $ | |||
3 | ** Stack and Call structure of Lua | |||
4 | ** See Copyright Notice in lua.h | |||
5 | */ | |||
6 | ||||
7 | #define ldo_c | |||
8 | #define LUA_CORE | |||
9 | ||||
10 | #include "lprefix.h" | |||
11 | ||||
12 | ||||
13 | #include <setjmp.h> | |||
14 | #include <stdlib.h> | |||
15 | #include <string.h> | |||
16 | ||||
17 | #include "lua.h" | |||
18 | ||||
19 | #include "lapi.h" | |||
20 | #include "ldebug.h" | |||
21 | #include "ldo.h" | |||
22 | #include "lfunc.h" | |||
23 | #include "lgc.h" | |||
24 | #include "lmem.h" | |||
25 | #include "lobject.h" | |||
26 | #include "lopcodes.h" | |||
27 | #include "lparser.h" | |||
28 | #include "lstate.h" | |||
29 | #include "lstring.h" | |||
30 | #include "ltable.h" | |||
31 | #include "ltm.h" | |||
32 | #include "lundump.h" | |||
33 | #include "lvm.h" | |||
34 | #include "lzio.h" | |||
35 | ||||
36 | ||||
37 | ||||
38 | #define errorstatus(s) ((s) > LUA_YIELD) | |||
39 | ||||
40 | ||||
41 | /* | |||
42 | ** {====================================================== | |||
43 | ** Error-recovery functions | |||
44 | ** ======================================================= | |||
45 | */ | |||
46 | ||||
47 | /* | |||
48 | ** LUAI_THROW/LUAI_TRY define how Lua does exception handling. By | |||
49 | ** default, Lua handles errors with exceptions when compiling as | |||
50 | ** C++ code, with _longjmp/_setjmp when asked to use them, and with | |||
51 | ** longjmp/setjmp otherwise. | |||
52 | */ | |||
53 | #if !defined(LUAI_THROW) /* { */ | |||
54 | ||||
55 | #if defined(__cplusplus) && !defined(LUA_USE_LONGJMP) /* { */ | |||
56 | ||||
57 | /* C++ exceptions */ | |||
58 | #define LUAI_THROW(L,c) throw(c) | |||
59 | #define LUAI_TRY(L,c,a) \ | |||
60 | try { a } catch(...) { if ((c)->status == 0) (c)->status = -1; } | |||
61 | #define luai_jmpbuf int /* dummy variable */ | |||
62 | ||||
63 | #elif defined(LUA_USE_POSIX) /* }{ */ | |||
64 | ||||
65 | /* in POSIX, try _longjmp/_setjmp (more efficient) */ | |||
66 | #define LUAI_THROW(L,c) _longjmp((c)->b, 1) | |||
67 | #define LUAI_TRY(L,c,a) if (_setjmp((c)->b) == 0) { a } | |||
68 | #define luai_jmpbuf jmp_buf | |||
69 | ||||
70 | #else /* }{ */ | |||
71 | ||||
72 | /* ISO C handling with long jumps */ | |||
73 | #define LUAI_THROW(L,c) longjmp((c)->b, 1) | |||
74 | #define LUAI_TRY(L,c,a) if (setjmp((c)->b) == 0) { a } | |||
75 | #define luai_jmpbuf jmp_buf | |||
76 | ||||
77 | #endif /* } */ | |||
78 | ||||
79 | #endif /* } */ | |||
80 | ||||
81 | ||||
82 | ||||
83 | /* chain list of long jump buffers */ | |||
84 | struct lua_longjmp { | |||
85 | struct lua_longjmp *previous; | |||
86 | luai_jmpbuf b; | |||
87 | volatile int status; /* error code */ | |||
88 | }; | |||
89 | ||||
90 | ||||
91 | 7 | void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) { | ||
92 |
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7 | switch (errcode) { | |
93 | ✗ | case LUA_ERRMEM: { /* memory error? */ | ||
94 | ✗ | setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */ | ||
95 | ✗ | break; | ||
96 | } | |||
97 | ✗ | case LUA_ERRERR: { | ||
98 | ✗ | setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling")); | ||
99 | ✗ | break; | ||
100 | } | |||
101 | ✗ | case LUA_OK: { /* special case only for closing upvalues */ | ||
102 | ✗ | setnilvalue(s2v(oldtop)); /* no error message */ | ||
103 | ✗ | break; | ||
104 | } | |||
105 |
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7 | default: { | |
106 | lua_assert(errorstatus(errcode)); /* real error */ | |||
107 | 7 | setobjs2s(L, oldtop, L->top.p - 1); /* error message on current top */ | ||
108 | 7 | break; | ||
109 | } | |||
110 | } | |||
111 | 7 | L->top.p = oldtop + 1; | ||
112 | 7 | } | ||
113 | ||||
114 | ||||
115 | 7 | l_noret luaD_throw (lua_State *L, int errcode) { | ||
116 |
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7 | if (L->errorJmp) { /* thread has an error handler? */ |
117 | 7 | L->errorJmp->status = errcode; /* set status */ | ||
118 | 7 | LUAI_THROW(L, L->errorJmp); /* jump to it */ | ||
119 | } | |||
120 | else { /* thread has no error handler */ | |||
121 | ✗ | global_State *g = G(L); | ||
122 | ✗ | errcode = luaE_resetthread(L, errcode); /* close all upvalues */ | ||
123 | ✗ | if (g->mainthread->errorJmp) { /* main thread has a handler? */ | ||
124 | ✗ | setobjs2s(L, g->mainthread->top.p++, L->top.p - 1); /* copy error obj. */ | ||
125 | ✗ | luaD_throw(g->mainthread, errcode); /* re-throw in main thread */ | ||
126 | } | |||
127 | else { /* no handler at all; abort */ | |||
128 | ✗ | if (g->panic) { /* panic function? */ | ||
129 | lua_unlock(L); | |||
130 | ✗ | g->panic(L); /* call panic function (last chance to jump out) */ | ||
131 | } | |||
132 | ✗ | abort(); | ||
133 | } | |||
134 | } | |||
135 | } | |||
136 | ||||
137 | ||||
138 | 3200 | int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) { | ||
139 | 3200 | l_uint32 oldnCcalls = L->nCcalls; | ||
140 | struct lua_longjmp lj; | |||
141 | 3200 | lj.status = LUA_OK; | ||
142 | 3200 | lj.previous = L->errorJmp; /* chain new error handler */ | ||
143 | 3200 | L->errorJmp = &lj; | ||
144 |
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3200 | LUAI_TRY(L, &lj, | |
145 | (*f)(L, ud); | |||
146 | ); | |||
147 | 3200 | L->errorJmp = lj.previous; /* restore old error handler */ | ||
148 | 3200 | L->nCcalls = oldnCcalls; | ||
149 | 3200 | return lj.status; | ||
150 | } | |||
151 | ||||
152 | /* }====================================================== */ | |||
153 | ||||
154 | ||||
155 | /* | |||
156 | ** {================================================================== | |||
157 | ** Stack reallocation | |||
158 | ** =================================================================== | |||
159 | */ | |||
160 | ||||
161 | ||||
162 | /* | |||
163 | ** Change all pointers to the stack into offsets. | |||
164 | */ | |||
165 | ✗ | static void relstack (lua_State *L) { | ||
166 | CallInfo *ci; | |||
167 | UpVal *up; | |||
168 | ✗ | L->top.offset = savestack(L, L->top.p); | ||
169 | ✗ | L->tbclist.offset = savestack(L, L->tbclist.p); | ||
170 | ✗ | for (up = L->openupval; up != NULL; up = up->u.open.next) | ||
171 | ✗ | up->v.offset = savestack(L, uplevel(up)); | ||
172 | ✗ | for (ci = L->ci; ci != NULL; ci = ci->previous) { | ||
173 | ✗ | ci->top.offset = savestack(L, ci->top.p); | ||
174 | ✗ | ci->func.offset = savestack(L, ci->func.p); | ||
175 | } | |||
176 | ✗ | } | ||
177 | ||||
178 | ||||
179 | /* | |||
180 | ** Change back all offsets into pointers. | |||
181 | */ | |||
182 | ✗ | static void correctstack (lua_State *L) { | ||
183 | CallInfo *ci; | |||
184 | UpVal *up; | |||
185 | ✗ | L->top.p = restorestack(L, L->top.offset); | ||
186 | ✗ | L->tbclist.p = restorestack(L, L->tbclist.offset); | ||
187 | ✗ | for (up = L->openupval; up != NULL; up = up->u.open.next) | ||
188 | ✗ | up->v.p = s2v(restorestack(L, up->v.offset)); | ||
189 | ✗ | for (ci = L->ci; ci != NULL; ci = ci->previous) { | ||
190 | ✗ | ci->top.p = restorestack(L, ci->top.offset); | ||
191 | ✗ | ci->func.p = restorestack(L, ci->func.offset); | ||
192 | ✗ | if (isLua(ci)) | ||
193 | ✗ | ci->u.l.trap = 1; /* signal to update 'trap' in 'luaV_execute' */ | ||
194 | } | |||
195 | ✗ | } | ||
196 | ||||
197 | ||||
198 | /* some space for error handling */ | |||
199 | #define ERRORSTACKSIZE (LUAI_MAXSTACK + 200) | |||
200 | ||||
201 | /* | |||
202 | ** Reallocate the stack to a new size, correcting all pointers into it. | |||
203 | ** In ISO C, any pointer use after the pointer has been deallocated is | |||
204 | ** undefined behavior. So, before the reallocation, all pointers are | |||
205 | ** changed to offsets, and after the reallocation they are changed back | |||
206 | ** to pointers. As during the reallocation the pointers are invalid, the | |||
207 | ** reallocation cannot run emergency collections. | |||
208 | ** | |||
209 | ** In case of allocation error, raise an error or return false according | |||
210 | ** to 'raiseerror'. | |||
211 | */ | |||
212 | ✗ | int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) { | ||
213 | ✗ | int oldsize = stacksize(L); | ||
214 | int i; | |||
215 | StkId newstack; | |||
216 | ✗ | int oldgcstop = G(L)->gcstopem; | ||
217 | lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE); | |||
218 | ✗ | relstack(L); /* change pointers to offsets */ | ||
219 | ✗ | G(L)->gcstopem = 1; /* stop emergency collection */ | ||
220 | ✗ | newstack = luaM_reallocvector(L, L->stack.p, oldsize + EXTRA_STACK, | ||
221 | newsize + EXTRA_STACK, StackValue); | |||
222 | ✗ | G(L)->gcstopem = oldgcstop; /* restore emergency collection */ | ||
223 | ✗ | if (l_unlikely(newstack == NULL)) { /* reallocation failed? */ | ||
224 | ✗ | correctstack(L); /* change offsets back to pointers */ | ||
225 | ✗ | if (raiseerror) | ||
226 | ✗ | luaM_error(L); | ||
227 | ✗ | else return 0; /* do not raise an error */ | ||
228 | } | |||
229 | ✗ | L->stack.p = newstack; | ||
230 | ✗ | correctstack(L); /* change offsets back to pointers */ | ||
231 | ✗ | L->stack_last.p = L->stack.p + newsize; | ||
232 | ✗ | for (i = oldsize + EXTRA_STACK; i < newsize + EXTRA_STACK; i++) | ||
233 | ✗ | setnilvalue(s2v(newstack + i)); /* erase new segment */ | ||
234 | ✗ | return 1; | ||
235 | } | |||
236 | ||||
237 | ||||
238 | /* | |||
239 | ** Try to grow the stack by at least 'n' elements. When 'raiseerror' | |||
240 | ** is true, raises any error; otherwise, return 0 in case of errors. | |||
241 | */ | |||
242 | ✗ | int luaD_growstack (lua_State *L, int n, int raiseerror) { | ||
243 | ✗ | int size = stacksize(L); | ||
244 | ✗ | if (l_unlikely(size > LUAI_MAXSTACK)) { | ||
245 | /* if stack is larger than maximum, thread is already using the | |||
246 | extra space reserved for errors, that is, thread is handling | |||
247 | a stack error; cannot grow further than that. */ | |||
248 | lua_assert(stacksize(L) == ERRORSTACKSIZE); | |||
249 | ✗ | if (raiseerror) | ||
250 | ✗ | luaD_throw(L, LUA_ERRERR); /* error inside message handler */ | ||
251 | ✗ | return 0; /* if not 'raiseerror', just signal it */ | ||
252 | } | |||
253 | ✗ | else if (n < LUAI_MAXSTACK) { /* avoids arithmetic overflows */ | ||
254 | ✗ | int newsize = 2 * size; /* tentative new size */ | ||
255 | ✗ | int needed = cast_int(L->top.p - L->stack.p) + n; | ||
256 | ✗ | if (newsize > LUAI_MAXSTACK) /* cannot cross the limit */ | ||
257 | ✗ | newsize = LUAI_MAXSTACK; | ||
258 | ✗ | if (newsize < needed) /* but must respect what was asked for */ | ||
259 | ✗ | newsize = needed; | ||
260 | ✗ | if (l_likely(newsize <= LUAI_MAXSTACK)) | ||
261 | ✗ | return luaD_reallocstack(L, newsize, raiseerror); | ||
262 | } | |||
263 | /* else stack overflow */ | |||
264 | /* add extra size to be able to handle the error message */ | |||
265 | ✗ | luaD_reallocstack(L, ERRORSTACKSIZE, raiseerror); | ||
266 | ✗ | if (raiseerror) | ||
267 | ✗ | luaG_runerror(L, "stack overflow"); | ||
268 | ✗ | return 0; | ||
269 | } | |||
270 | ||||
271 | ||||
272 | /* | |||
273 | ** Compute how much of the stack is being used, by computing the | |||
274 | ** maximum top of all call frames in the stack and the current top. | |||
275 | */ | |||
276 | 934 | static int stackinuse (lua_State *L) { | ||
277 | CallInfo *ci; | |||
278 | int res; | |||
279 | 934 | StkId lim = L->top.p; | ||
280 |
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1868 | for (ci = L->ci; ci != NULL; ci = ci->previous) { |
281 |
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934 | if (lim < ci->top.p) lim = ci->top.p; |
282 | } | |||
283 | lua_assert(lim <= L->stack_last.p + EXTRA_STACK); | |||
284 | 934 | res = cast_int(lim - L->stack.p) + 1; /* part of stack in use */ | ||
285 |
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934 | if (res < LUA_MINSTACK) |
286 | ✗ | res = LUA_MINSTACK; /* ensure a minimum size */ | ||
287 | 934 | return res; | ||
288 | } | |||
289 | ||||
290 | ||||
291 | /* | |||
292 | ** If stack size is more than 3 times the current use, reduce that size | |||
293 | ** to twice the current use. (So, the final stack size is at most 2/3 the | |||
294 | ** previous size, and half of its entries are empty.) | |||
295 | ** As a particular case, if stack was handling a stack overflow and now | |||
296 | ** it is not, 'max' (limited by LUAI_MAXSTACK) will be smaller than | |||
297 | ** stacksize (equal to ERRORSTACKSIZE in this case), and so the stack | |||
298 | ** will be reduced to a "regular" size. | |||
299 | */ | |||
300 |
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934 | void luaD_shrinkstack (lua_State *L) { | |
301 | 934 | int inuse = stackinuse(L); | ||
302 |
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934 | int max = (inuse > LUAI_MAXSTACK / 3) ? LUAI_MAXSTACK : inuse * 3; | |
303 | /* if thread is currently not handling a stack overflow and its | |||
304 | size is larger than maximum "reasonable" size, shrink it */ | |||
305 |
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934 | if (inuse <= LUAI_MAXSTACK && stacksize(L) > max) { |
306 | ✗ | int nsize = (inuse > LUAI_MAXSTACK / 2) ? LUAI_MAXSTACK : inuse * 2; | ||
307 | ✗ | luaD_reallocstack(L, nsize, 0); /* ok if that fails */ | ||
308 | } | |||
309 | else /* don't change stack */ | |||
310 | condmovestack(L,{},{}); /* (change only for debugging) */ | |||
311 | 934 | luaE_shrinkCI(L); /* shrink CI list */ | ||
312 | 934 | } | ||
313 | ||||
314 | ||||
315 | 618 | void luaD_inctop (lua_State *L) { | ||
316 |
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618 | luaD_checkstack(L, 1); | |
317 | 618 | L->top.p++; | ||
318 | 618 | } | ||
319 | ||||
320 | /* }================================================================== */ | |||
321 | ||||
322 | ||||
323 | /* | |||
324 | ** Call a hook for the given event. Make sure there is a hook to be | |||
325 | ** called. (Both 'L->hook' and 'L->hookmask', which trigger this | |||
326 | ** function, can be changed asynchronously by signals.) | |||
327 | */ | |||
328 | ✗ | void luaD_hook (lua_State *L, int event, int line, | ||
329 | int ftransfer, int ntransfer) { | |||
330 | ✗ | lua_Hook hook = L->hook; | ||
331 | ✗ | if (hook && L->allowhook) { /* make sure there is a hook */ | ||
332 | ✗ | int mask = CIST_HOOKED; | ||
333 | ✗ | CallInfo *ci = L->ci; | ||
334 | ✗ | ptrdiff_t top = savestack(L, L->top.p); /* preserve original 'top' */ | ||
335 | ✗ | ptrdiff_t ci_top = savestack(L, ci->top.p); /* idem for 'ci->top' */ | ||
336 | lua_Debug ar; | |||
337 | ✗ | ar.event = event; | ||
338 | ✗ | ar.currentline = line; | ||
339 | ✗ | ar.i_ci = ci; | ||
340 | ✗ | if (ntransfer != 0) { | ||
341 | ✗ | mask |= CIST_TRAN; /* 'ci' has transfer information */ | ||
342 | ✗ | ci->u2.transferinfo.ftransfer = ftransfer; | ||
343 | ✗ | ci->u2.transferinfo.ntransfer = ntransfer; | ||
344 | } | |||
345 | ✗ | if (isLua(ci) && L->top.p < ci->top.p) | ||
346 | ✗ | L->top.p = ci->top.p; /* protect entire activation register */ | ||
347 | ✗ | luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ | ||
348 | ✗ | if (ci->top.p < L->top.p + LUA_MINSTACK) | ||
349 | ✗ | ci->top.p = L->top.p + LUA_MINSTACK; | ||
350 | ✗ | L->allowhook = 0; /* cannot call hooks inside a hook */ | ||
351 | ✗ | ci->callstatus |= mask; | ||
352 | lua_unlock(L); | |||
353 | ✗ | (*hook)(L, &ar); | ||
354 | lua_lock(L); | |||
355 | lua_assert(!L->allowhook); | |||
356 | ✗ | L->allowhook = 1; | ||
357 | ✗ | ci->top.p = restorestack(L, ci_top); | ||
358 | ✗ | L->top.p = restorestack(L, top); | ||
359 | ✗ | ci->callstatus &= ~mask; | ||
360 | } | |||
361 | ✗ | } | ||
362 | ||||
363 | ||||
364 | /* | |||
365 | ** Executes a call hook for Lua functions. This function is called | |||
366 | ** whenever 'hookmask' is not zero, so it checks whether call hooks are | |||
367 | ** active. | |||
368 | */ | |||
369 | ✗ | void luaD_hookcall (lua_State *L, CallInfo *ci) { | ||
370 | ✗ | L->oldpc = 0; /* set 'oldpc' for new function */ | ||
371 | ✗ | if (L->hookmask & LUA_MASKCALL) { /* is call hook on? */ | ||
372 | ✗ | int event = (ci->callstatus & CIST_TAIL) ? LUA_HOOKTAILCALL | ||
373 | ✗ | : LUA_HOOKCALL; | ||
374 | ✗ | Proto *p = ci_func(ci)->p; | ||
375 | ✗ | ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */ | ||
376 | ✗ | luaD_hook(L, event, -1, 1, p->numparams); | ||
377 | ✗ | ci->u.l.savedpc--; /* correct 'pc' */ | ||
378 | } | |||
379 | ✗ | } | ||
380 | ||||
381 | ||||
382 | /* | |||
383 | ** Executes a return hook for Lua and C functions and sets/corrects | |||
384 | ** 'oldpc'. (Note that this correction is needed by the line hook, so it | |||
385 | ** is done even when return hooks are off.) | |||
386 | */ | |||
387 | ✗ | static void rethook (lua_State *L, CallInfo *ci, int nres) { | ||
388 | ✗ | if (L->hookmask & LUA_MASKRET) { /* is return hook on? */ | ||
389 | ✗ | StkId firstres = L->top.p - nres; /* index of first result */ | ||
390 | ✗ | int delta = 0; /* correction for vararg functions */ | ||
391 | int ftransfer; | |||
392 | ✗ | if (isLua(ci)) { | ||
393 | ✗ | Proto *p = ci_func(ci)->p; | ||
394 | ✗ | if (p->is_vararg) | ||
395 | ✗ | delta = ci->u.l.nextraargs + p->numparams + 1; | ||
396 | } | |||
397 | ✗ | ci->func.p += delta; /* if vararg, back to virtual 'func' */ | ||
398 | ✗ | ftransfer = cast(unsigned short, firstres - ci->func.p); | ||
399 | ✗ | luaD_hook(L, LUA_HOOKRET, -1, ftransfer, nres); /* call it */ | ||
400 | ✗ | ci->func.p -= delta; | ||
401 | } | |||
402 | ✗ | if (isLua(ci = ci->previous)) | ||
403 | ✗ | L->oldpc = pcRel(ci->u.l.savedpc, ci_func(ci)->p); /* set 'oldpc' */ | ||
404 | ✗ | } | ||
405 | ||||
406 | ||||
407 | /* | |||
408 | ** Check whether 'func' has a '__call' metafield. If so, put it in the | |||
409 | ** stack, below original 'func', so that 'luaD_precall' can call it. Raise | |||
410 | ** an error if there is no '__call' metafield. | |||
411 | */ | |||
412 | ✗ | StkId luaD_tryfuncTM (lua_State *L, StkId func) { | ||
413 | const TValue *tm; | |||
414 | StkId p; | |||
415 | ✗ | checkstackGCp(L, 1, func); /* space for metamethod */ | ||
416 | ✗ | tm = luaT_gettmbyobj(L, s2v(func), TM_CALL); /* (after previous GC) */ | ||
417 | ✗ | if (l_unlikely(ttisnil(tm))) | ||
418 | ✗ | luaG_callerror(L, s2v(func)); /* nothing to call */ | ||
419 | ✗ | for (p = L->top.p; p > func; p--) /* open space for metamethod */ | ||
420 | ✗ | setobjs2s(L, p, p-1); | ||
421 | ✗ | L->top.p++; /* stack space pre-allocated by the caller */ | ||
422 | ✗ | setobj2s(L, func, tm); /* metamethod is the new function to be called */ | ||
423 | ✗ | return func; | ||
424 | } | |||
425 | ||||
426 | ||||
427 | /* | |||
428 | ** Given 'nres' results at 'firstResult', move 'wanted' of them to 'res'. | |||
429 | ** Handle most typical cases (zero results for commands, one result for | |||
430 | ** expressions, multiple results for tail calls/single parameters) | |||
431 | ** separated. | |||
432 | */ | |||
433 | 3087 | l_sinline void moveresults (lua_State *L, StkId res, int nres, int wanted) { | ||
434 | StkId firstresult; | |||
435 | int i; | |||
436 |
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3087 | switch (wanted) { /* handle typical cases separately */ | |
437 |
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2129 | case 0: /* no values needed */ | |
438 | 2129 | L->top.p = res; | ||
439 | 2129 | return; | ||
440 |
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572 | case 1: /* one value needed */ | |
441 |
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572 | if (nres == 0) /* no results? */ |
442 | ✗ | setnilvalue(s2v(res)); /* adjust with nil */ | ||
443 | else /* at least one result */ | |||
444 | 572 | setobjs2s(L, res, L->top.p - nres); /* move it to proper place */ | ||
445 | 572 | L->top.p = res + 1; | ||
446 | 572 | return; | ||
447 |
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|
386 | case LUA_MULTRET: | |
448 | 386 | wanted = nres; /* we want all results */ | ||
449 | 386 | break; | ||
450 | ✗ | default: /* two/more results and/or to-be-closed variables */ | ||
451 | ✗ | if (hastocloseCfunc(wanted)) { /* to-be-closed variables? */ | ||
452 | ✗ | L->ci->callstatus |= CIST_CLSRET; /* in case of yields */ | ||
453 | ✗ | L->ci->u2.nres = nres; | ||
454 | ✗ | res = luaF_close(L, res, CLOSEKTOP, 1); | ||
455 | ✗ | L->ci->callstatus &= ~CIST_CLSRET; | ||
456 | ✗ | if (L->hookmask) { /* if needed, call hook after '__close's */ | ||
457 | ✗ | ptrdiff_t savedres = savestack(L, res); | ||
458 | ✗ | rethook(L, L->ci, nres); | ||
459 | ✗ | res = restorestack(L, savedres); /* hook can move stack */ | ||
460 | } | |||
461 | ✗ | wanted = decodeNresults(wanted); | ||
462 | ✗ | if (wanted == LUA_MULTRET) | ||
463 | ✗ | wanted = nres; /* we want all results */ | ||
464 | } | |||
465 | ✗ | break; | ||
466 | } | |||
467 | /* generic case */ | |||
468 | 386 | firstresult = L->top.p - nres; /* index of first result */ | ||
469 |
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386 | if (nres > wanted) /* extra results? */ |
470 | ✗ | nres = wanted; /* don't need them */ | ||
471 |
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470 | for (i = 0; i < nres; i++) /* move all results to correct place */ |
472 | 84 | setobjs2s(L, res + i, firstresult + i); | ||
473 |
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386 | for (; i < wanted; i++) /* complete wanted number of results */ |
474 | ✗ | setnilvalue(s2v(res + i)); | ||
475 | 386 | L->top.p = res + wanted; /* top points after the last result */ | ||
476 | } | |||
477 | ||||
478 | ||||
479 | /* | |||
480 | ** Finishes a function call: calls hook if necessary, moves current | |||
481 | ** number of results to proper place, and returns to previous call | |||
482 | ** info. If function has to close variables, hook must be called after | |||
483 | ** that. | |||
484 | */ | |||
485 | 3087 | void luaD_poscall (lua_State *L, CallInfo *ci, int nres) { | ||
486 | 3087 | int wanted = ci->nresults; | ||
487 |
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3087 | if (l_unlikely(L->hookmask && !hastocloseCfunc(wanted))) |
488 | ✗ | rethook(L, ci, nres); | ||
489 | /* move results to proper place */ | |||
490 | 3087 | moveresults(L, ci->func.p, nres, wanted); | ||
491 | /* function cannot be in any of these cases when returning */ | |||
492 | lua_assert(!(ci->callstatus & | |||
493 | (CIST_HOOKED | CIST_YPCALL | CIST_FIN | CIST_TRAN | CIST_CLSRET))); | |||
494 | 3087 | L->ci = ci->previous; /* back to caller (after closing variables) */ | ||
495 | 3087 | } | ||
496 | ||||
497 | ||||
498 | ||||
499 | #define next_ci(L) (L->ci->next ? L->ci->next : luaE_extendCI(L)) | |||
500 | ||||
501 | ||||
502 | 3329 | l_sinline CallInfo *prepCallInfo (lua_State *L, StkId func, int nret, | ||
503 | int mask, StkId top) { | |||
504 |
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3329 | CallInfo *ci = L->ci = next_ci(L); /* new frame */ | |
505 | 3329 | ci->func.p = func; | ||
506 | 3329 | ci->nresults = nret; | ||
507 | 3329 | ci->callstatus = mask; | ||
508 | 3329 | ci->top.p = top; | ||
509 | 3329 | return ci; | ||
510 | } | |||
511 | ||||
512 | ||||
513 | /* | |||
514 | ** precall for C functions | |||
515 | */ | |||
516 | 2773 | l_sinline int precallC (lua_State *L, StkId func, int nresults, | ||
517 | lua_CFunction f) { | |||
518 | int n; /* number of returns */ | |||
519 | CallInfo *ci; | |||
520 |
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2773 | checkstackGCp(L, LUA_MINSTACK, func); /* ensure minimum stack size */ | |
521 | 5546 | L->ci = ci = prepCallInfo(L, func, nresults, CIST_C, | ||
522 | 2773 | L->top.p + LUA_MINSTACK); | ||
523 | lua_assert(ci->top.p <= L->stack_last.p); | |||
524 |
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2773 | if (l_unlikely(L->hookmask & LUA_MASKCALL)) { |
525 | ✗ | int narg = cast_int(L->top.p - func) - 1; | ||
526 | ✗ | luaD_hook(L, LUA_HOOKCALL, -1, 1, narg); | ||
527 | } | |||
528 | lua_unlock(L); | |||
529 | 2773 | n = (*f)(L); /* do the actual call */ | ||
530 | lua_lock(L); | |||
531 | api_checknelems(L, n); | |||
532 | 2767 | luaD_poscall(L, ci, n); | ||
533 | 2767 | return n; | ||
534 | } | |||
535 | ||||
536 | ||||
537 | /* | |||
538 | ** Prepare a function for a tail call, building its call info on top | |||
539 | ** of the current call info. 'narg1' is the number of arguments plus 1 | |||
540 | ** (so that it includes the function itself). Return the number of | |||
541 | ** results, if it was a C function, or -1 for a Lua function. | |||
542 | */ | |||
543 | 59 | int luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, | ||
544 | int narg1, int delta) { | |||
545 | 59 | retry: | ||
546 |
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59 | switch (ttypetag(s2v(func))) { | |
547 |
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|
2 | case LUA_VCCL: /* C closure */ | |
548 | 2 | return precallC(L, func, LUA_MULTRET, clCvalue(s2v(func))->f); | ||
549 |
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|
16 | case LUA_VLCF: /* light C function */ | |
550 | 16 | return precallC(L, func, LUA_MULTRET, fvalue(s2v(func))); | ||
551 |
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|
41 | case LUA_VLCL: { /* Lua function */ | |
552 | 41 | Proto *p = clLvalue(s2v(func))->p; | ||
553 | 41 | int fsize = p->maxstacksize; /* frame size */ | ||
554 | 41 | int nfixparams = p->numparams; | ||
555 | int i; | |||
556 |
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41 | checkstackGCp(L, fsize - delta, func); | |
557 | 41 | ci->func.p -= delta; /* restore 'func' (if vararg) */ | ||
558 |
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|
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|
186 | for (i = 0; i < narg1; i++) /* move down function and arguments */ |
559 | 145 | setobjs2s(L, ci->func.p + i, func + i); | ||
560 | 41 | func = ci->func.p; /* moved-down function */ | ||
561 |
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41 | for (; narg1 <= nfixparams; narg1++) |
562 | ✗ | setnilvalue(s2v(func + narg1)); /* complete missing arguments */ | ||
563 | 41 | ci->top.p = func + 1 + fsize; /* top for new function */ | ||
564 | lua_assert(ci->top.p <= L->stack_last.p); | |||
565 | 41 | ci->u.l.savedpc = p->code; /* starting point */ | ||
566 | 41 | ci->callstatus |= CIST_TAIL; | ||
567 | 41 | L->top.p = func + narg1; /* set top */ | ||
568 | 41 | return -1; | ||
569 | } | |||
570 | ✗ | default: { /* not a function */ | ||
571 | ✗ | func = luaD_tryfuncTM(L, func); /* try to get '__call' metamethod */ | ||
572 | /* return luaD_pretailcall(L, ci, func, narg1 + 1, delta); */ | |||
573 | ✗ | narg1++; | ||
574 | ✗ | goto retry; /* try again */ | ||
575 | } | |||
576 | } | |||
577 | } | |||
578 | ||||
579 | ||||
580 | /* | |||
581 | ** Prepares the call to a function (C or Lua). For C functions, also do | |||
582 | ** the call. The function to be called is at '*func'. The arguments | |||
583 | ** are on the stack, right after the function. Returns the CallInfo | |||
584 | ** to be executed, if it was a Lua function. Otherwise (a C function) | |||
585 | ** returns NULL, with all the results on the stack, starting at the | |||
586 | ** original function position. | |||
587 | */ | |||
588 | 3311 | CallInfo *luaD_precall (lua_State *L, StkId func, int nresults) { | ||
589 | 3311 | retry: | ||
590 |
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3311 | switch (ttypetag(s2v(func))) { | |
591 |
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|
38 | case LUA_VCCL: /* C closure */ | |
592 | 38 | precallC(L, func, nresults, clCvalue(s2v(func))->f); | ||
593 | 38 | return NULL; | ||
594 |
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|
2717 | case LUA_VLCF: /* light C function */ | |
595 | 2717 | precallC(L, func, nresults, fvalue(s2v(func))); | ||
596 | 2711 | return NULL; | ||
597 |
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|
556 | case LUA_VLCL: { /* Lua function */ | |
598 | CallInfo *ci; | |||
599 | 556 | Proto *p = clLvalue(s2v(func))->p; | ||
600 | 556 | int narg = cast_int(L->top.p - func) - 1; /* number of real arguments */ | ||
601 | 556 | int nfixparams = p->numparams; | ||
602 | 556 | int fsize = p->maxstacksize; /* frame size */ | ||
603 |
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556 | checkstackGCp(L, fsize, func); | |
604 | 556 | L->ci = ci = prepCallInfo(L, func, nresults, 0, func + 1 + fsize); | ||
605 | 556 | ci->u.l.savedpc = p->code; /* starting point */ | ||
606 |
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556 | for (; narg < nfixparams; narg++) |
607 | ✗ | setnilvalue(s2v(L->top.p++)); /* complete missing arguments */ | ||
608 | lua_assert(ci->top.p <= L->stack_last.p); | |||
609 | 556 | return ci; | ||
610 | } | |||
611 | ✗ | default: { /* not a function */ | ||
612 | ✗ | func = luaD_tryfuncTM(L, func); /* try to get '__call' metamethod */ | ||
613 | /* return luaD_precall(L, func, nresults); */ | |||
614 | ✗ | goto retry; /* try again with metamethod */ | ||
615 | } | |||
616 | } | |||
617 | } | |||
618 | ||||
619 | ||||
620 | /* | |||
621 | ** Call a function (C or Lua) through C. 'inc' can be 1 (increment | |||
622 | ** number of recursive invocations in the C stack) or nyci (the same | |||
623 | ** plus increment number of non-yieldable calls). | |||
624 | ** This function can be called with some use of EXTRA_STACK, so it should | |||
625 | ** check the stack before doing anything else. 'luaD_precall' already | |||
626 | ** does that. | |||
627 | */ | |||
628 | 2575 | l_sinline void ccall (lua_State *L, StkId func, int nResults, l_uint32 inc) { | ||
629 | CallInfo *ci; | |||
630 | 2575 | L->nCcalls += inc; | ||
631 |
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|
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2575 | if (l_unlikely(getCcalls(L) >= LUAI_MAXCCALLS)) { |
632 | ✗ | checkstackp(L, 0, func); /* free any use of EXTRA_STACK */ | ||
633 | ✗ | luaE_checkcstack(L); | ||
634 | } | |||
635 |
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|
2575 | if ((ci = luaD_precall(L, func, nResults)) != NULL) { /* Lua function? */ |
636 | 406 | ci->callstatus = CIST_FRESH; /* mark that it is a "fresh" execute */ | ||
637 | 406 | luaV_execute(L, ci); /* call it */ | ||
638 | } | |||
639 | 2569 | L->nCcalls -= inc; | ||
640 | 2569 | } | ||
641 | ||||
642 | ||||
643 | /* | |||
644 | ** External interface for 'ccall' | |||
645 | */ | |||
646 | ✗ | void luaD_call (lua_State *L, StkId func, int nResults) { | ||
647 | ✗ | ccall(L, func, nResults, 1); | ||
648 | ✗ | } | ||
649 | ||||
650 | ||||
651 | /* | |||
652 | ** Similar to 'luaD_call', but does not allow yields during the call. | |||
653 | */ | |||
654 | 2575 | void luaD_callnoyield (lua_State *L, StkId func, int nResults) { | ||
655 | 2575 | ccall(L, func, nResults, nyci); | ||
656 | 2569 | } | ||
657 | ||||
658 | ||||
659 | /* | |||
660 | ** Finish the job of 'lua_pcallk' after it was interrupted by an yield. | |||
661 | ** (The caller, 'finishCcall', does the final call to 'adjustresults'.) | |||
662 | ** The main job is to complete the 'luaD_pcall' called by 'lua_pcallk'. | |||
663 | ** If a '__close' method yields here, eventually control will be back | |||
664 | ** to 'finishCcall' (when that '__close' method finally returns) and | |||
665 | ** 'finishpcallk' will run again and close any still pending '__close' | |||
666 | ** methods. Similarly, if a '__close' method errs, 'precover' calls | |||
667 | ** 'unroll' which calls ''finishCcall' and we are back here again, to | |||
668 | ** close any pending '__close' methods. | |||
669 | ** Note that, up to the call to 'luaF_close', the corresponding | |||
670 | ** 'CallInfo' is not modified, so that this repeated run works like the | |||
671 | ** first one (except that it has at least one less '__close' to do). In | |||
672 | ** particular, field CIST_RECST preserves the error status across these | |||
673 | ** multiple runs, changing only if there is a new error. | |||
674 | */ | |||
675 | ✗ | static int finishpcallk (lua_State *L, CallInfo *ci) { | ||
676 | ✗ | int status = getcistrecst(ci); /* get original status */ | ||
677 | ✗ | if (l_likely(status == LUA_OK)) /* no error? */ | ||
678 | ✗ | status = LUA_YIELD; /* was interrupted by an yield */ | ||
679 | else { /* error */ | |||
680 | ✗ | StkId func = restorestack(L, ci->u2.funcidx); | ||
681 | ✗ | L->allowhook = getoah(ci->callstatus); /* restore 'allowhook' */ | ||
682 | ✗ | func = luaF_close(L, func, status, 1); /* can yield or raise an error */ | ||
683 | ✗ | luaD_seterrorobj(L, status, func); | ||
684 | ✗ | luaD_shrinkstack(L); /* restore stack size in case of overflow */ | ||
685 | ✗ | setcistrecst(ci, LUA_OK); /* clear original status */ | ||
686 | } | |||
687 | ✗ | ci->callstatus &= ~CIST_YPCALL; | ||
688 | ✗ | L->errfunc = ci->u.c.old_errfunc; | ||
689 | /* if it is here, there were errors or yields; unlike 'lua_pcallk', | |||
690 | do not change status */ | |||
691 | ✗ | return status; | ||
692 | } | |||
693 | ||||
694 | ||||
695 | /* | |||
696 | ** Completes the execution of a C function interrupted by an yield. | |||
697 | ** The interruption must have happened while the function was either | |||
698 | ** closing its tbc variables in 'moveresults' or executing | |||
699 | ** 'lua_callk'/'lua_pcallk'. In the first case, it just redoes | |||
700 | ** 'luaD_poscall'. In the second case, the call to 'finishpcallk' | |||
701 | ** finishes the interrupted execution of 'lua_pcallk'. After that, it | |||
702 | ** calls the continuation of the interrupted function and finally it | |||
703 | ** completes the job of the 'luaD_call' that called the function. In | |||
704 | ** the call to 'adjustresults', we do not know the number of results | |||
705 | ** of the function called by 'lua_callk'/'lua_pcallk', so we are | |||
706 | ** conservative and use LUA_MULTRET (always adjust). | |||
707 | */ | |||
708 | ✗ | static void finishCcall (lua_State *L, CallInfo *ci) { | ||
709 | int n; /* actual number of results from C function */ | |||
710 | ✗ | if (ci->callstatus & CIST_CLSRET) { /* was returning? */ | ||
711 | lua_assert(hastocloseCfunc(ci->nresults)); | |||
712 | ✗ | n = ci->u2.nres; /* just redo 'luaD_poscall' */ | ||
713 | /* don't need to reset CIST_CLSRET, as it will be set again anyway */ | |||
714 | } | |||
715 | else { | |||
716 | ✗ | int status = LUA_YIELD; /* default if there were no errors */ | ||
717 | /* must have a continuation and must be able to call it */ | |||
718 | lua_assert(ci->u.c.k != NULL && yieldable(L)); | |||
719 | ✗ | if (ci->callstatus & CIST_YPCALL) /* was inside a 'lua_pcallk'? */ | ||
720 | ✗ | status = finishpcallk(L, ci); /* finish it */ | ||
721 | ✗ | adjustresults(L, LUA_MULTRET); /* finish 'lua_callk' */ | ||
722 | lua_unlock(L); | |||
723 | ✗ | n = (*ci->u.c.k)(L, status, ci->u.c.ctx); /* call continuation */ | ||
724 | lua_lock(L); | |||
725 | api_checknelems(L, n); | |||
726 | } | |||
727 | ✗ | luaD_poscall(L, ci, n); /* finish 'luaD_call' */ | ||
728 | ✗ | } | ||
729 | ||||
730 | ||||
731 | /* | |||
732 | ** Executes "full continuation" (everything in the stack) of a | |||
733 | ** previously interrupted coroutine until the stack is empty (or another | |||
734 | ** interruption long-jumps out of the loop). | |||
735 | */ | |||
736 | ✗ | static void unroll (lua_State *L, void *ud) { | ||
737 | CallInfo *ci; | |||
738 | UNUSED(ud); | |||
739 | ✗ | while ((ci = L->ci) != &L->base_ci) { /* something in the stack */ | ||
740 | ✗ | if (!isLua(ci)) /* C function? */ | ||
741 | ✗ | finishCcall(L, ci); /* complete its execution */ | ||
742 | else { /* Lua function */ | |||
743 | ✗ | luaV_finishOp(L); /* finish interrupted instruction */ | ||
744 | ✗ | luaV_execute(L, ci); /* execute down to higher C 'boundary' */ | ||
745 | } | |||
746 | } | |||
747 | ✗ | } | ||
748 | ||||
749 | ||||
750 | /* | |||
751 | ** Try to find a suspended protected call (a "recover point") for the | |||
752 | ** given thread. | |||
753 | */ | |||
754 | ✗ | static CallInfo *findpcall (lua_State *L) { | ||
755 | CallInfo *ci; | |||
756 | ✗ | for (ci = L->ci; ci != NULL; ci = ci->previous) { /* search for a pcall */ | ||
757 | ✗ | if (ci->callstatus & CIST_YPCALL) | ||
758 | ✗ | return ci; | ||
759 | } | |||
760 | ✗ | return NULL; /* no pending pcall */ | ||
761 | } | |||
762 | ||||
763 | ||||
764 | /* | |||
765 | ** Signal an error in the call to 'lua_resume', not in the execution | |||
766 | ** of the coroutine itself. (Such errors should not be handled by any | |||
767 | ** coroutine error handler and should not kill the coroutine.) | |||
768 | */ | |||
769 | ✗ | static int resume_error (lua_State *L, const char *msg, int narg) { | ||
770 | ✗ | L->top.p -= narg; /* remove args from the stack */ | ||
771 | ✗ | setsvalue2s(L, L->top.p, luaS_new(L, msg)); /* push error message */ | ||
772 | ✗ | api_incr_top(L); | ||
773 | lua_unlock(L); | |||
774 | ✗ | return LUA_ERRRUN; | ||
775 | } | |||
776 | ||||
777 | ||||
778 | /* | |||
779 | ** Do the work for 'lua_resume' in protected mode. Most of the work | |||
780 | ** depends on the status of the coroutine: initial state, suspended | |||
781 | ** inside a hook, or regularly suspended (optionally with a continuation | |||
782 | ** function), plus erroneous cases: non-suspended coroutine or dead | |||
783 | ** coroutine. | |||
784 | */ | |||
785 | ✗ | static void resume (lua_State *L, void *ud) { | ||
786 | ✗ | int n = *(cast(int*, ud)); /* number of arguments */ | ||
787 | ✗ | StkId firstArg = L->top.p - n; /* first argument */ | ||
788 | ✗ | CallInfo *ci = L->ci; | ||
789 | ✗ | if (L->status == LUA_OK) /* starting a coroutine? */ | ||
790 | ✗ | ccall(L, firstArg - 1, LUA_MULTRET, 0); /* just call its body */ | ||
791 | else { /* resuming from previous yield */ | |||
792 | lua_assert(L->status == LUA_YIELD); | |||
793 | ✗ | L->status = LUA_OK; /* mark that it is running (again) */ | ||
794 | ✗ | if (isLua(ci)) { /* yielded inside a hook? */ | ||
795 | ✗ | L->top.p = firstArg; /* discard arguments */ | ||
796 | ✗ | luaV_execute(L, ci); /* just continue running Lua code */ | ||
797 | } | |||
798 | else { /* 'common' yield */ | |||
799 | ✗ | if (ci->u.c.k != NULL) { /* does it have a continuation function? */ | ||
800 | lua_unlock(L); | |||
801 | ✗ | n = (*ci->u.c.k)(L, LUA_YIELD, ci->u.c.ctx); /* call continuation */ | ||
802 | lua_lock(L); | |||
803 | api_checknelems(L, n); | |||
804 | } | |||
805 | ✗ | luaD_poscall(L, ci, n); /* finish 'luaD_call' */ | ||
806 | } | |||
807 | ✗ | unroll(L, NULL); /* run continuation */ | ||
808 | } | |||
809 | ✗ | } | ||
810 | ||||
811 | ||||
812 | /* | |||
813 | ** Unrolls a coroutine in protected mode while there are recoverable | |||
814 | ** errors, that is, errors inside a protected call. (Any error | |||
815 | ** interrupts 'unroll', and this loop protects it again so it can | |||
816 | ** continue.) Stops with a normal end (status == LUA_OK), an yield | |||
817 | ** (status == LUA_YIELD), or an unprotected error ('findpcall' doesn't | |||
818 | ** find a recover point). | |||
819 | */ | |||
820 | ✗ | static int precover (lua_State *L, int status) { | ||
821 | CallInfo *ci; | |||
822 | ✗ | while (errorstatus(status) && (ci = findpcall(L)) != NULL) { | ||
823 | ✗ | L->ci = ci; /* go down to recovery functions */ | ||
824 | ✗ | setcistrecst(ci, status); /* status to finish 'pcall' */ | ||
825 | ✗ | status = luaD_rawrunprotected(L, unroll, NULL); | ||
826 | } | |||
827 | ✗ | return status; | ||
828 | } | |||
829 | ||||
830 | ||||
831 | ✗ | LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs, | ||
832 | int *nresults) { | |||
833 | int status; | |||
834 | lua_lock(L); | |||
835 | ✗ | if (L->status == LUA_OK) { /* may be starting a coroutine */ | ||
836 | ✗ | if (L->ci != &L->base_ci) /* not in base level? */ | ||
837 | ✗ | return resume_error(L, "cannot resume non-suspended coroutine", nargs); | ||
838 | ✗ | else if (L->top.p - (L->ci->func.p + 1) == nargs) /* no function? */ | ||
839 | ✗ | return resume_error(L, "cannot resume dead coroutine", nargs); | ||
840 | } | |||
841 | ✗ | else if (L->status != LUA_YIELD) /* ended with errors? */ | ||
842 | ✗ | return resume_error(L, "cannot resume dead coroutine", nargs); | ||
843 | ✗ | L->nCcalls = (from) ? getCcalls(from) : 0; | ||
844 | ✗ | if (getCcalls(L) >= LUAI_MAXCCALLS) | ||
845 | ✗ | return resume_error(L, "C stack overflow", nargs); | ||
846 | ✗ | L->nCcalls++; | ||
847 | luai_userstateresume(L, nargs); | |||
848 | api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs); | |||
849 | ✗ | status = luaD_rawrunprotected(L, resume, &nargs); | ||
850 | /* continue running after recoverable errors */ | |||
851 | ✗ | status = precover(L, status); | ||
852 | ✗ | if (l_likely(!errorstatus(status))) | ||
853 | lua_assert(status == L->status); /* normal end or yield */ | |||
854 | else { /* unrecoverable error */ | |||
855 | ✗ | L->status = cast_byte(status); /* mark thread as 'dead' */ | ||
856 | ✗ | luaD_seterrorobj(L, status, L->top.p); /* push error message */ | ||
857 | ✗ | L->ci->top.p = L->top.p; | ||
858 | } | |||
859 | ✗ | *nresults = (status == LUA_YIELD) ? L->ci->u2.nyield | ||
860 | ✗ | : cast_int(L->top.p - (L->ci->func.p + 1)); | ||
861 | lua_unlock(L); | |||
862 | ✗ | return status; | ||
863 | } | |||
864 | ||||
865 | ||||
866 | ✗ | LUA_API int lua_isyieldable (lua_State *L) { | ||
867 | ✗ | return yieldable(L); | ||
868 | } | |||
869 | ||||
870 | ||||
871 | ✗ | LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx, | ||
872 | lua_KFunction k) { | |||
873 | CallInfo *ci; | |||
874 | luai_userstateyield(L, nresults); | |||
875 | lua_lock(L); | |||
876 | ✗ | ci = L->ci; | ||
877 | api_checknelems(L, nresults); | |||
878 | ✗ | if (l_unlikely(!yieldable(L))) { | ||
879 | ✗ | if (L != G(L)->mainthread) | ||
880 | ✗ | luaG_runerror(L, "attempt to yield across a C-call boundary"); | ||
881 | else | |||
882 | ✗ | luaG_runerror(L, "attempt to yield from outside a coroutine"); | ||
883 | } | |||
884 | ✗ | L->status = LUA_YIELD; | ||
885 | ✗ | ci->u2.nyield = nresults; /* save number of results */ | ||
886 | ✗ | if (isLua(ci)) { /* inside a hook? */ | ||
887 | lua_assert(!isLuacode(ci)); | |||
888 | api_check(L, nresults == 0, "hooks cannot yield values"); | |||
889 | api_check(L, k == NULL, "hooks cannot continue after yielding"); | |||
890 | } | |||
891 | else { | |||
892 | ✗ | if ((ci->u.c.k = k) != NULL) /* is there a continuation? */ | ||
893 | ✗ | ci->u.c.ctx = ctx; /* save context */ | ||
894 | ✗ | luaD_throw(L, LUA_YIELD); | ||
895 | } | |||
896 | lua_assert(ci->callstatus & CIST_HOOKED); /* must be inside a hook */ | |||
897 | lua_unlock(L); | |||
898 | ✗ | return 0; /* return to 'luaD_hook' */ | ||
899 | } | |||
900 | ||||
901 | ||||
902 | /* | |||
903 | ** Auxiliary structure to call 'luaF_close' in protected mode. | |||
904 | */ | |||
905 | struct CloseP { | |||
906 | StkId level; | |||
907 | int status; | |||
908 | }; | |||
909 | ||||
910 | ||||
911 | /* | |||
912 | ** Auxiliary function to call 'luaF_close' in protected mode. | |||
913 | */ | |||
914 | 316 | static void closepaux (lua_State *L, void *ud) { | ||
915 | 316 | struct CloseP *pcl = cast(struct CloseP *, ud); | ||
916 | 316 | luaF_close(L, pcl->level, pcl->status, 0); | ||
917 | 316 | } | ||
918 | ||||
919 | ||||
920 | /* | |||
921 | ** Calls 'luaF_close' in protected mode. Return the original status | |||
922 | ** or, in case of errors, the new status. | |||
923 | */ | |||
924 |
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316 | int luaD_closeprotected (lua_State *L, ptrdiff_t level, int status) { | |
925 | 316 | CallInfo *old_ci = L->ci; | ||
926 | 316 | lu_byte old_allowhooks = L->allowhook; | ||
927 | ✗ | for (;;) { /* keep closing upvalues until no more errors */ | ||
928 | struct CloseP pcl; | |||
929 | 316 | pcl.level = restorestack(L, level); pcl.status = status; | ||
930 | 316 | status = luaD_rawrunprotected(L, &closepaux, &pcl); | ||
931 |
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316 | if (l_likely(status == LUA_OK)) /* no more errors? */ |
932 | 316 | return pcl.status; | ||
933 | else { /* an error occurred; restore saved state and repeat */ | |||
934 | ✗ | L->ci = old_ci; | ||
935 | ✗ | L->allowhook = old_allowhooks; | ||
936 | } | |||
937 | } | |||
938 | } | |||
939 | ||||
940 | ||||
941 | /* | |||
942 | ** Call the C function 'func' in protected mode, restoring basic | |||
943 | ** thread information ('allowhook', etc.) and in particular | |||
944 | ** its stack level in case of errors. | |||
945 | */ | |||
946 |
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2575 | int luaD_pcall (lua_State *L, Pfunc func, void *u, | |
947 | ptrdiff_t old_top, ptrdiff_t ef) { | |||
948 | int status; | |||
949 | 2575 | CallInfo *old_ci = L->ci; | ||
950 | 2575 | lu_byte old_allowhooks = L->allowhook; | ||
951 | 2575 | ptrdiff_t old_errfunc = L->errfunc; | ||
952 | 2575 | L->errfunc = ef; | ||
953 | 2575 | status = luaD_rawrunprotected(L, func, u); | ||
954 |
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2575 | if (l_unlikely(status != LUA_OK)) { /* an error occurred? */ |
955 | 7 | L->ci = old_ci; | ||
956 | 7 | L->allowhook = old_allowhooks; | ||
957 | 7 | status = luaD_closeprotected(L, old_top, status); | ||
958 | 7 | luaD_seterrorobj(L, status, restorestack(L, old_top)); | ||
959 | 7 | luaD_shrinkstack(L); /* restore stack size in case of overflow */ | ||
960 | } | |||
961 | 2575 | L->errfunc = old_errfunc; | ||
962 | 2575 | return status; | ||
963 | } | |||
964 | ||||
965 | ||||
966 | ||||
967 | /* | |||
968 | ** Execute a protected parser. | |||
969 | */ | |||
970 | struct SParser { /* data to 'f_parser' */ | |||
971 | ZIO *z; | |||
972 | Mbuffer buff; /* dynamic structure used by the scanner */ | |||
973 | Dyndata dyd; /* dynamic structures used by the parser */ | |||
974 | const char *mode; | |||
975 | const char *name; | |||
976 | }; | |||
977 | ||||
978 | ||||
979 | 309 | static void checkmode (lua_State *L, const char *mode, const char *x) { | ||
980 |
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309 | if (mode && strchr(mode, x[0]) == NULL) { |
981 | ✗ | luaO_pushfstring(L, | ||
982 | "attempt to load a %s chunk (mode is '%s')", x, mode); | |||
983 | ✗ | luaD_throw(L, LUA_ERRSYNTAX); | ||
984 | } | |||
985 | 309 | } | ||
986 | ||||
987 | ||||
988 | 309 | static void f_parser (lua_State *L, void *ud) { | ||
989 | LClosure *cl; | |||
990 | 309 | struct SParser *p = cast(struct SParser *, ud); | ||
991 |
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309 | int c = zgetc(p->z); /* read first character */ | |
992 |
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309 | if (c == LUA_SIGNATURE[0]) { |
993 | ✗ | checkmode(L, p->mode, "binary"); | ||
994 | ✗ | cl = luaU_undump(L, p->z, p->name); | ||
995 | } | |||
996 | else { | |||
997 | 309 | checkmode(L, p->mode, "text"); | ||
998 | 309 | cl = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c); | ||
999 | } | |||
1000 | lua_assert(cl->nupvalues == cl->p->sizeupvalues); | |||
1001 | 308 | luaF_initupvals(L, cl); | ||
1002 | 308 | } | ||
1003 | ||||
1004 | ||||
1005 | 309 | int luaD_protectedparser (lua_State *L, ZIO *z, const char *name, | ||
1006 | const char *mode) { | |||
1007 | struct SParser p; | |||
1008 | int status; | |||
1009 | 309 | incnny(L); /* cannot yield during parsing */ | ||
1010 | 309 | p.z = z; p.name = name; p.mode = mode; | ||
1011 | 309 | p.dyd.actvar.arr = NULL; p.dyd.actvar.size = 0; | ||
1012 | 309 | p.dyd.gt.arr = NULL; p.dyd.gt.size = 0; | ||
1013 | 309 | p.dyd.label.arr = NULL; p.dyd.label.size = 0; | ||
1014 | 309 | luaZ_initbuffer(L, &p.buff); | ||
1015 | 309 | status = luaD_pcall(L, f_parser, &p, savestack(L, L->top.p), L->errfunc); | ||
1016 | 309 | luaZ_freebuffer(L, &p.buff); | ||
1017 | 309 | luaM_freearray(L, p.dyd.actvar.arr, p.dyd.actvar.size); | ||
1018 | 309 | luaM_freearray(L, p.dyd.gt.arr, p.dyd.gt.size); | ||
1019 | 309 | luaM_freearray(L, p.dyd.label.arr, p.dyd.label.size); | ||
1020 | 309 | decnny(L); | ||
1021 | 309 | return status; | ||
1022 | } | |||
1023 | ||||
1024 | ||||
1025 |