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1 | /* | |
2 | * tclProc.c -- | |
3 | * | |
4 | * This file contains routines that implement Tcl procedures, | |
5 | * including the "proc" and "uplevel" commands. | |
6 | * | |
7 | * Copyright 1987-1991 Regents of the University of California | |
8 | * Permission to use, copy, modify, and distribute this | |
9 | * software and its documentation for any purpose and without | |
10 | * fee is hereby granted, provided that the above copyright | |
11 | * notice appear in all copies. The University of California | |
12 | * makes no representations about the suitability of this | |
13 | * software for any purpose. It is provided "as is" without | |
14 | * express or implied warranty. | |
15 | */ | |
16 | ||
17 | #ifndef lint | |
18 | static char rcsid[] = "$Header: /sprite/src/lib/tcl/RCS/tclProc.c,v 1.59 91/09/30 16:59:54 ouster Exp $ SPRITE (Berkeley)"; | |
19 | #endif | |
20 | ||
21 | #include "tclint.h" | |
22 | ||
23 | /* | |
24 | * Forward references to procedures defined later in this file: | |
25 | */ | |
26 | ||
27 | static int InterpProc _ANSI_ARGS_((ClientData clientData, | |
28 | Tcl_Interp *interp, int argc, char **argv)); | |
29 | static void ProcDeleteProc _ANSI_ARGS_((ClientData clientData)); | |
30 | \f | |
31 | /* | |
32 | *---------------------------------------------------------------------- | |
33 | * | |
34 | * Tcl_ProcCmd -- | |
35 | * | |
36 | * This procedure is invoked to process the "proc" Tcl command. | |
37 | * See the user documentation for details on what it does. | |
38 | * | |
39 | * Results: | |
40 | * A standard Tcl result value. | |
41 | * | |
42 | * Side effects: | |
43 | * A new procedure gets created. | |
44 | * | |
45 | *---------------------------------------------------------------------- | |
46 | */ | |
47 | ||
48 | /* ARGSUSED */ | |
49 | int | |
50 | Tcl_ProcCmd(dummy, interp, argc, argv) | |
51 | ClientData dummy; /* Not used. */ | |
52 | Tcl_Interp *interp; /* Current interpreter. */ | |
53 | int argc; /* Number of arguments. */ | |
54 | char **argv; /* Argument strings. */ | |
55 | { | |
56 | register Interp *iPtr = (Interp *) interp; | |
57 | register Proc *procPtr; | |
58 | int result, argCount, i; | |
59 | char **argArray = NULL; | |
60 | Arg *lastArgPtr; | |
61 | register Arg *argPtr = NULL; /* Initialization not needed, but | |
62 | * prevents compiler warning. */ | |
63 | ||
64 | if (argc != 4) { | |
65 | Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], | |
66 | " name args body\"", (char *) NULL); | |
67 | return TCL_ERROR; | |
68 | } | |
69 | ||
70 | procPtr = (Proc *) ckalloc(sizeof(Proc)); | |
71 | procPtr->iPtr = iPtr; | |
72 | procPtr->command = (char *) ckalloc((unsigned) strlen(argv[3]) + 1); | |
73 | strcpy(procPtr->command, argv[3]); | |
74 | procPtr->argPtr = NULL; | |
75 | ||
76 | /* | |
77 | * Break up the argument list into argument specifiers, then process | |
78 | * each argument specifier. | |
79 | */ | |
80 | ||
81 | result = Tcl_SplitList(interp, argv[2], &argCount, &argArray); | |
82 | if (result != TCL_OK) { | |
83 | goto procError; | |
84 | } | |
85 | lastArgPtr = NULL; | |
86 | for (i = 0; i < argCount; i++) { | |
87 | int fieldCount, nameLength, valueLength; | |
88 | char **fieldValues; | |
89 | ||
90 | /* | |
91 | * Now divide the specifier up into name and default. | |
92 | */ | |
93 | ||
94 | result = Tcl_SplitList(interp, argArray[i], &fieldCount, | |
95 | &fieldValues); | |
96 | if (result != TCL_OK) { | |
97 | goto procError; | |
98 | } | |
99 | if (fieldCount > 2) { | |
100 | ckfree((char *) fieldValues); | |
101 | Tcl_AppendResult(interp, | |
102 | "too many fields in argument specifier \"", | |
103 | argArray[i], "\"", (char *) NULL); | |
104 | result = TCL_ERROR; | |
105 | goto procError; | |
106 | } | |
107 | if ((fieldCount == 0) || (*fieldValues[0] == 0)) { | |
108 | ckfree((char *) fieldValues); | |
109 | Tcl_AppendResult(interp, "procedure \"", argv[1], | |
110 | "\" has argument with no name", (char *) NULL); | |
111 | result = TCL_ERROR; | |
112 | goto procError; | |
113 | } | |
114 | nameLength = strlen(fieldValues[0]) + 1; | |
115 | if (fieldCount == 2) { | |
116 | valueLength = strlen(fieldValues[1]) + 1; | |
117 | } else { | |
118 | valueLength = 0; | |
119 | } | |
120 | argPtr = (Arg *) ckalloc((unsigned) | |
121 | (sizeof(Arg) - sizeof(argPtr->name) + nameLength | |
122 | + valueLength)); | |
123 | if (lastArgPtr == NULL) { | |
124 | procPtr->argPtr = argPtr; | |
125 | } else { | |
126 | lastArgPtr->nextPtr = argPtr; | |
127 | } | |
128 | lastArgPtr = argPtr; | |
129 | argPtr->nextPtr = NULL; | |
130 | strcpy(argPtr->name, fieldValues[0]); | |
131 | if (fieldCount == 2) { | |
132 | argPtr->defValue = argPtr->name + nameLength; | |
133 | strcpy(argPtr->defValue, fieldValues[1]); | |
134 | } else { | |
135 | argPtr->defValue = NULL; | |
136 | } | |
137 | ckfree((char *) fieldValues); | |
138 | } | |
139 | ||
140 | Tcl_CreateCommand(interp, argv[1], InterpProc, (ClientData) procPtr, | |
141 | ProcDeleteProc); | |
142 | ckfree((char *) argArray); | |
143 | return TCL_OK; | |
144 | ||
145 | procError: | |
146 | ckfree(procPtr->command); | |
147 | while (procPtr->argPtr != NULL) { | |
148 | argPtr = procPtr->argPtr; | |
149 | procPtr->argPtr = argPtr->nextPtr; | |
150 | ckfree((char *) argPtr); | |
151 | } | |
152 | ckfree((char *) procPtr); | |
153 | if (argArray != NULL) { | |
154 | ckfree((char *) argArray); | |
155 | } | |
156 | return result; | |
157 | } | |
158 | \f | |
159 | /* | |
160 | *---------------------------------------------------------------------- | |
161 | * | |
162 | * TclGetFrame -- | |
163 | * | |
164 | * Given a description of a procedure frame, such as the first | |
165 | * argument to an "uplevel" or "upvar" command, locate the | |
166 | * call frame for the appropriate level of procedure. | |
167 | * | |
168 | * Results: | |
169 | * The return value is -1 if an error occurred in finding the | |
170 | * frame (in this case an error message is left in interp->result). | |
171 | * 1 is returned if string was either a number or a number preceded | |
172 | * by "#" and it specified a valid frame. 0 is returned if string | |
173 | * isn't one of the two things above (in this case, the lookup | |
174 | * acts as if string were "1"). The variable pointed to by | |
175 | * framePtrPtr is filled in with the address of the desired frame | |
176 | * (unless an error occurs, in which case it isn't modified). | |
177 | * | |
178 | * Side effects: | |
179 | * None. | |
180 | * | |
181 | *---------------------------------------------------------------------- | |
182 | */ | |
183 | ||
184 | int | |
185 | TclGetFrame(interp, string, framePtrPtr) | |
186 | Tcl_Interp *interp; /* Interpreter in which to find frame. */ | |
187 | char *string; /* String describing frame. */ | |
188 | CallFrame **framePtrPtr; /* Store pointer to frame here (or NULL | |
189 | * if global frame indicated). */ | |
190 | { | |
191 | register Interp *iPtr = (Interp *) interp; | |
192 | int level, result; | |
193 | CallFrame *framePtr; | |
194 | ||
195 | if (iPtr->varFramePtr == NULL) { | |
196 | iPtr->result = "already at top level"; | |
197 | return -1; | |
198 | } | |
199 | ||
200 | /* | |
201 | * Parse string to figure out which level number to go to. | |
202 | */ | |
203 | ||
204 | result = 1; | |
205 | if (*string == '#') { | |
206 | if (Tcl_GetInt(interp, string+1, &level) != TCL_OK) { | |
207 | return -1; | |
208 | } | |
209 | if (level < 0) { | |
210 | levelError: | |
211 | Tcl_AppendResult(interp, "bad level \"", string, "\"", | |
212 | (char *) NULL); | |
213 | return -1; | |
214 | } | |
215 | } else if (isdigit(*string)) { | |
216 | if (Tcl_GetInt(interp, string, &level) != TCL_OK) { | |
217 | return -1; | |
218 | } | |
219 | level = iPtr->varFramePtr->level - level; | |
220 | } else { | |
221 | level = iPtr->varFramePtr->level - 1; | |
222 | result = 0; | |
223 | } | |
224 | ||
225 | /* | |
226 | * Figure out which frame to use, and modify the interpreter so | |
227 | * its variables come from that frame. | |
228 | */ | |
229 | ||
230 | if (level == 0) { | |
231 | framePtr = NULL; | |
232 | } else { | |
233 | for (framePtr = iPtr->varFramePtr; framePtr != NULL; | |
234 | framePtr = framePtr->callerVarPtr) { | |
235 | if (framePtr->level == level) { | |
236 | break; | |
237 | } | |
238 | } | |
239 | if (framePtr == NULL) { | |
240 | goto levelError; | |
241 | } | |
242 | } | |
243 | *framePtrPtr = framePtr; | |
244 | return result; | |
245 | } | |
246 | \f | |
247 | /* | |
248 | *---------------------------------------------------------------------- | |
249 | * | |
250 | * Tcl_UplevelCmd -- | |
251 | * | |
252 | * This procedure is invoked to process the "uplevel" Tcl command. | |
253 | * See the user documentation for details on what it does. | |
254 | * | |
255 | * Results: | |
256 | * A standard Tcl result value. | |
257 | * | |
258 | * Side effects: | |
259 | * See the user documentation. | |
260 | * | |
261 | *---------------------------------------------------------------------- | |
262 | */ | |
263 | ||
264 | /* ARGSUSED */ | |
265 | int | |
266 | Tcl_UplevelCmd(dummy, interp, argc, argv) | |
267 | ClientData dummy; /* Not used. */ | |
268 | Tcl_Interp *interp; /* Current interpreter. */ | |
269 | int argc; /* Number of arguments. */ | |
270 | char **argv; /* Argument strings. */ | |
271 | { | |
272 | register Interp *iPtr = (Interp *) interp; | |
273 | int result; | |
274 | CallFrame *savedVarFramePtr, *framePtr; | |
275 | ||
276 | if (argc < 2) { | |
277 | uplevelSyntax: | |
278 | Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], | |
279 | " ?level? command ?command ...?\"", (char *) NULL); | |
280 | return TCL_ERROR; | |
281 | } | |
282 | ||
283 | /* | |
284 | * Find the level to use for executing the command. | |
285 | */ | |
286 | ||
287 | result = TclGetFrame(interp, argv[1], &framePtr); | |
288 | if (result == -1) { | |
289 | return TCL_ERROR; | |
290 | } | |
291 | argc -= (result+1); | |
292 | argv += (result+1); | |
293 | ||
294 | /* | |
295 | * Modify the interpreter state to execute in the given frame. | |
296 | */ | |
297 | ||
298 | savedVarFramePtr = iPtr->varFramePtr; | |
299 | iPtr->varFramePtr = framePtr; | |
300 | ||
301 | /* | |
302 | * Execute the residual arguments as a command. | |
303 | */ | |
304 | ||
305 | if (argc == 0) { | |
306 | goto uplevelSyntax; | |
307 | } | |
308 | if (argc == 1) { | |
309 | result = Tcl_Eval(interp, argv[0], 0, (char **) NULL); | |
310 | } else { | |
311 | char *cmd; | |
312 | ||
313 | cmd = Tcl_Concat(argc, argv); | |
314 | result = Tcl_Eval(interp, cmd, 0, (char **) NULL); | |
315 | ckfree(cmd); | |
316 | } | |
317 | if (result == TCL_ERROR) { | |
318 | char msg[60]; | |
319 | sprintf(msg, "\n (\"uplevel\" body line %d)", interp->errorLine); | |
320 | Tcl_AddErrorInfo(interp, msg); | |
321 | } | |
322 | ||
323 | /* | |
324 | * Restore the variable frame, and return. | |
325 | */ | |
326 | ||
327 | iPtr->varFramePtr = savedVarFramePtr; | |
328 | return result; | |
329 | } | |
330 | \f | |
331 | /* | |
332 | *---------------------------------------------------------------------- | |
333 | * | |
334 | * TclFindProc -- | |
335 | * | |
336 | * Given the name of a procedure, return a pointer to the | |
337 | * record describing the procedure. | |
338 | * | |
339 | * Results: | |
340 | * NULL is returned if the name doesn't correspond to any | |
341 | * procedure. Otherwise the return value is a pointer to | |
342 | * the procedure's record. | |
343 | * | |
344 | * Side effects: | |
345 | * None. | |
346 | * | |
347 | *---------------------------------------------------------------------- | |
348 | */ | |
349 | ||
350 | Proc * | |
351 | TclFindProc(iPtr, procName) | |
352 | Interp *iPtr; /* Interpreter in which to look. */ | |
353 | char *procName; /* Name of desired procedure. */ | |
354 | { | |
355 | Tcl_HashEntry *hPtr; | |
356 | Command *cmdPtr; | |
357 | ||
358 | hPtr = Tcl_FindHashEntry(&iPtr->commandTable, procName); | |
359 | if (hPtr == NULL) { | |
360 | return NULL; | |
361 | } | |
362 | cmdPtr = (Command *) Tcl_GetHashValue(hPtr); | |
363 | if (cmdPtr->proc != InterpProc) { | |
364 | return NULL; | |
365 | } | |
366 | return (Proc *) cmdPtr->clientData; | |
367 | } | |
368 | \f | |
369 | /* | |
370 | *---------------------------------------------------------------------- | |
371 | * | |
372 | * TclIsProc -- | |
373 | * | |
374 | * Tells whether a command is a Tcl procedure or not. | |
375 | * | |
376 | * Results: | |
377 | * If the given command is actuall a Tcl procedure, the | |
378 | * return value is the address of the record describing | |
379 | * the procedure. Otherwise the return value is 0. | |
380 | * | |
381 | * Side effects: | |
382 | * None. | |
383 | * | |
384 | *---------------------------------------------------------------------- | |
385 | */ | |
386 | ||
387 | Proc * | |
388 | TclIsProc(cmdPtr) | |
389 | Command *cmdPtr; /* Command to test. */ | |
390 | { | |
391 | if (cmdPtr->proc == InterpProc) { | |
392 | return (Proc *) cmdPtr->clientData; | |
393 | } | |
394 | return (Proc *) 0; | |
395 | } | |
396 | \f | |
397 | /* | |
398 | *---------------------------------------------------------------------- | |
399 | * | |
400 | * InterpProc -- | |
401 | * | |
402 | * When a Tcl procedure gets invoked, this routine gets invoked | |
403 | * to interpret the procedure. | |
404 | * | |
405 | * Results: | |
406 | * A standard Tcl result value, usually TCL_OK. | |
407 | * | |
408 | * Side effects: | |
409 | * Depends on the commands in the procedure. | |
410 | * | |
411 | *---------------------------------------------------------------------- | |
412 | */ | |
413 | ||
414 | static int | |
415 | InterpProc(clientData, interp, argc, argv) | |
416 | ClientData clientData; /* Record describing procedure to be | |
417 | * interpreted. */ | |
418 | Tcl_Interp *interp; /* Interpreter in which procedure was | |
419 | * invoked. */ | |
420 | int argc; /* Count of number of arguments to this | |
421 | * procedure. */ | |
422 | char **argv; /* Argument values. */ | |
423 | { | |
424 | register Proc *procPtr = (Proc *) clientData; | |
425 | register Arg *argPtr; | |
426 | register Interp *iPtr = (Interp *) interp; | |
427 | char **args; | |
428 | CallFrame frame; | |
429 | char *value, *end; | |
430 | int result; | |
431 | ||
432 | /* | |
433 | * Set up a call frame for the new procedure invocation. | |
434 | */ | |
435 | ||
436 | iPtr = procPtr->iPtr; | |
437 | Tcl_InitHashTable(&frame.varTable, TCL_STRING_KEYS); | |
438 | if (iPtr->varFramePtr != NULL) { | |
439 | frame.level = iPtr->varFramePtr->level + 1; | |
440 | } else { | |
441 | frame.level = 1; | |
442 | } | |
443 | frame.argc = argc; | |
444 | frame.argv = argv; | |
445 | frame.callerPtr = iPtr->framePtr; | |
446 | frame.callerVarPtr = iPtr->varFramePtr; | |
447 | iPtr->framePtr = &frame; | |
448 | iPtr->varFramePtr = &frame; | |
449 | ||
450 | /* | |
451 | * Match the actual arguments against the procedure's formal | |
452 | * parameters to compute local variables. | |
453 | */ | |
454 | ||
455 | for (argPtr = procPtr->argPtr, args = argv+1, argc -= 1; | |
456 | argPtr != NULL; | |
457 | argPtr = argPtr->nextPtr, args++, argc--) { | |
458 | ||
459 | /* | |
460 | * Handle the special case of the last formal being "args". When | |
461 | * it occurs, assign it a list consisting of all the remaining | |
462 | * actual arguments. | |
463 | */ | |
464 | ||
465 | if ((argPtr->nextPtr == NULL) | |
466 | && (strcmp(argPtr->name, "args") == 0)) { | |
467 | if (argc < 0) { | |
468 | argc = 0; | |
469 | } | |
470 | value = Tcl_Merge(argc, args); | |
471 | Tcl_SetVar(interp, argPtr->name, value, 0); | |
472 | ckfree(value); | |
473 | argc = 0; | |
474 | break; | |
475 | } else if (argc > 0) { | |
476 | value = *args; | |
477 | } else if (argPtr->defValue != NULL) { | |
478 | value = argPtr->defValue; | |
479 | } else { | |
480 | Tcl_AppendResult(interp, "no value given for parameter \"", | |
481 | argPtr->name, "\" to \"", argv[0], "\"", | |
482 | (char *) NULL); | |
483 | result = TCL_ERROR; | |
484 | goto procDone; | |
485 | } | |
486 | Tcl_SetVar(interp, argPtr->name, value, 0); | |
487 | } | |
488 | if (argc > 0) { | |
489 | Tcl_AppendResult(interp, "called \"", argv[0], | |
490 | "\" with too many arguments", (char *) NULL); | |
491 | result = TCL_ERROR; | |
492 | goto procDone; | |
493 | } | |
494 | ||
495 | /* | |
496 | * Invoke the commands in the procedure's body. | |
497 | */ | |
498 | ||
499 | result = Tcl_Eval(interp, procPtr->command, 0, &end); | |
500 | if (result == TCL_RETURN) { | |
501 | result = TCL_OK; | |
502 | } else if (result == TCL_ERROR) { | |
503 | char msg[100]; | |
504 | ||
505 | /* | |
506 | * Record information telling where the error occurred. | |
507 | */ | |
508 | ||
509 | sprintf(msg, "\n (procedure \"%.50s\" line %d)", argv[0], | |
510 | iPtr->errorLine); | |
511 | Tcl_AddErrorInfo(interp, msg); | |
512 | } else if (result == TCL_BREAK) { | |
513 | iPtr->result = "invoked \"break\" outside of a loop"; | |
514 | result = TCL_ERROR; | |
515 | } else if (result == TCL_CONTINUE) { | |
516 | iPtr->result = "invoked \"continue\" outside of a loop"; | |
517 | result = TCL_ERROR; | |
518 | } | |
519 | ||
520 | /* | |
521 | * Delete the call frame for this procedure invocation (it's | |
522 | * important to remove the call frame from the interpreter | |
523 | * before deleting it, so that traces invoked during the | |
524 | * deletion don't see the partially-deleted frame). | |
525 | */ | |
526 | ||
527 | procDone: | |
528 | iPtr->framePtr = frame.callerPtr; | |
529 | iPtr->varFramePtr = frame.callerVarPtr; | |
530 | TclDeleteVars(iPtr, &frame.varTable); | |
531 | return result; | |
532 | } | |
533 | \f | |
534 | /* | |
535 | *---------------------------------------------------------------------- | |
536 | * | |
537 | * ProcDeleteProc -- | |
538 | * | |
539 | * This procedure is invoked just before a command procedure is | |
540 | * removed from an interpreter. Its job is to release all the | |
541 | * resources allocated to the procedure. | |
542 | * | |
543 | * Results: | |
544 | * None. | |
545 | * | |
546 | * Side effects: | |
547 | * Memory gets freed. | |
548 | * | |
549 | *---------------------------------------------------------------------- | |
550 | */ | |
551 | ||
552 | static void | |
553 | ProcDeleteProc(clientData) | |
554 | ClientData clientData; /* Procedure to be deleted. */ | |
555 | { | |
556 | register Proc *procPtr = (Proc *) clientData; | |
557 | register Arg *argPtr; | |
558 | ||
559 | ckfree((char *) procPtr->command); | |
560 | for (argPtr = procPtr->argPtr; argPtr != NULL; ) { | |
561 | Arg *nextPtr = argPtr->nextPtr; | |
562 | ||
563 | ckfree((char *) argPtr); | |
564 | argPtr = nextPtr; | |
565 | } | |
566 | ckfree((char *) procPtr); | |
567 | } |