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1 | /* Perform an inferior function call, for GDB, the GNU debugger. | |
2 | ||
3 | Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, | |
4 | 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, | |
5 | 2008 Free Software Foundation, Inc. | |
6 | ||
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 3 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
21 | ||
22 | #include "defs.h" | |
23 | #include "breakpoint.h" | |
24 | #include "target.h" | |
25 | #include "regcache.h" | |
26 | #include "inferior.h" | |
27 | #include "gdb_assert.h" | |
28 | #include "block.h" | |
29 | #include "gdbcore.h" | |
30 | #include "language.h" | |
31 | #include "objfiles.h" | |
32 | #include "gdbcmd.h" | |
33 | #include "command.h" | |
34 | #include "gdb_string.h" | |
35 | #include "infcall.h" | |
36 | #include "dummy-frame.h" | |
37 | #include "ada-lang.h" | |
38 | #include "gdbthread.h" | |
39 | ||
40 | /* NOTE: cagney/2003-04-16: What's the future of this code? | |
41 | ||
42 | GDB needs an asynchronous expression evaluator, that means an | |
43 | asynchronous inferior function call implementation, and that in | |
44 | turn means restructuring the code so that it is event driven. */ | |
45 | ||
46 | /* How you should pass arguments to a function depends on whether it | |
47 | was defined in K&R style or prototype style. If you define a | |
48 | function using the K&R syntax that takes a `float' argument, then | |
49 | callers must pass that argument as a `double'. If you define the | |
50 | function using the prototype syntax, then you must pass the | |
51 | argument as a `float', with no promotion. | |
52 | ||
53 | Unfortunately, on certain older platforms, the debug info doesn't | |
54 | indicate reliably how each function was defined. A function type's | |
55 | TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was | |
56 | defined in prototype style. When calling a function whose | |
57 | TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to | |
58 | decide what to do. | |
59 | ||
60 | For modern targets, it is proper to assume that, if the prototype | |
61 | flag is clear, that can be trusted: `float' arguments should be | |
62 | promoted to `double'. For some older targets, if the prototype | |
63 | flag is clear, that doesn't tell us anything. The default is to | |
64 | trust the debug information; the user can override this behavior | |
65 | with "set coerce-float-to-double 0". */ | |
66 | ||
67 | static int coerce_float_to_double_p = 1; | |
68 | static void | |
69 | show_coerce_float_to_double_p (struct ui_file *file, int from_tty, | |
70 | struct cmd_list_element *c, const char *value) | |
71 | { | |
72 | fprintf_filtered (file, _("\ | |
73 | Coercion of floats to doubles when calling functions is %s.\n"), | |
74 | value); | |
75 | } | |
76 | ||
77 | /* This boolean tells what gdb should do if a signal is received while | |
78 | in a function called from gdb (call dummy). If set, gdb unwinds | |
79 | the stack and restore the context to what as it was before the | |
80 | call. | |
81 | ||
82 | The default is to stop in the frame where the signal was received. */ | |
83 | ||
84 | int unwind_on_signal_p = 0; | |
85 | static void | |
86 | show_unwind_on_signal_p (struct ui_file *file, int from_tty, | |
87 | struct cmd_list_element *c, const char *value) | |
88 | { | |
89 | fprintf_filtered (file, _("\ | |
90 | Unwinding of stack if a signal is received while in a call dummy is %s.\n"), | |
91 | value); | |
92 | } | |
93 | ||
94 | ||
95 | /* Perform the standard coercions that are specified | |
96 | for arguments to be passed to C or Ada functions. | |
97 | ||
98 | If PARAM_TYPE is non-NULL, it is the expected parameter type. | |
99 | IS_PROTOTYPED is non-zero if the function declaration is prototyped. | |
100 | SP is the stack pointer were additional data can be pushed (updating | |
101 | its value as needed). */ | |
102 | ||
103 | static struct value * | |
104 | value_arg_coerce (struct gdbarch *gdbarch, struct value *arg, | |
105 | struct type *param_type, int is_prototyped, CORE_ADDR *sp) | |
106 | { | |
107 | const struct builtin_type *builtin = builtin_type (gdbarch); | |
108 | struct type *arg_type = check_typedef (value_type (arg)); | |
109 | struct type *type | |
110 | = param_type ? check_typedef (param_type) : arg_type; | |
111 | ||
112 | /* Perform any Ada-specific coercion first. */ | |
113 | if (current_language->la_language == language_ada) | |
114 | arg = ada_convert_actual (arg, type, sp); | |
115 | ||
116 | /* Force the value to the target if we will need its address. At | |
117 | this point, we could allocate arguments on the stack instead of | |
118 | calling malloc if we knew that their addresses would not be | |
119 | saved by the called function. */ | |
120 | arg = value_coerce_to_target (arg); | |
121 | ||
122 | switch (TYPE_CODE (type)) | |
123 | { | |
124 | case TYPE_CODE_REF: | |
125 | { | |
126 | struct value *new_value; | |
127 | ||
128 | if (TYPE_CODE (arg_type) == TYPE_CODE_REF) | |
129 | return value_cast_pointers (type, arg); | |
130 | ||
131 | /* Cast the value to the reference's target type, and then | |
132 | convert it back to a reference. This will issue an error | |
133 | if the value was not previously in memory - in some cases | |
134 | we should clearly be allowing this, but how? */ | |
135 | new_value = value_cast (TYPE_TARGET_TYPE (type), arg); | |
136 | new_value = value_ref (new_value); | |
137 | return new_value; | |
138 | } | |
139 | case TYPE_CODE_INT: | |
140 | case TYPE_CODE_CHAR: | |
141 | case TYPE_CODE_BOOL: | |
142 | case TYPE_CODE_ENUM: | |
143 | /* If we don't have a prototype, coerce to integer type if necessary. */ | |
144 | if (!is_prototyped) | |
145 | { | |
146 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int)) | |
147 | type = builtin->builtin_int; | |
148 | } | |
149 | /* Currently all target ABIs require at least the width of an integer | |
150 | type for an argument. We may have to conditionalize the following | |
151 | type coercion for future targets. */ | |
152 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int)) | |
153 | type = builtin->builtin_int; | |
154 | break; | |
155 | case TYPE_CODE_FLT: | |
156 | if (!is_prototyped && coerce_float_to_double_p) | |
157 | { | |
158 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_double)) | |
159 | type = builtin->builtin_double; | |
160 | else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin->builtin_double)) | |
161 | type = builtin->builtin_long_double; | |
162 | } | |
163 | break; | |
164 | case TYPE_CODE_FUNC: | |
165 | type = lookup_pointer_type (type); | |
166 | break; | |
167 | case TYPE_CODE_ARRAY: | |
168 | /* Arrays are coerced to pointers to their first element, unless | |
169 | they are vectors, in which case we want to leave them alone, | |
170 | because they are passed by value. */ | |
171 | if (current_language->c_style_arrays) | |
172 | if (!TYPE_VECTOR (type)) | |
173 | type = lookup_pointer_type (TYPE_TARGET_TYPE (type)); | |
174 | break; | |
175 | case TYPE_CODE_UNDEF: | |
176 | case TYPE_CODE_PTR: | |
177 | case TYPE_CODE_STRUCT: | |
178 | case TYPE_CODE_UNION: | |
179 | case TYPE_CODE_VOID: | |
180 | case TYPE_CODE_SET: | |
181 | case TYPE_CODE_RANGE: | |
182 | case TYPE_CODE_STRING: | |
183 | case TYPE_CODE_BITSTRING: | |
184 | case TYPE_CODE_ERROR: | |
185 | case TYPE_CODE_MEMBERPTR: | |
186 | case TYPE_CODE_METHODPTR: | |
187 | case TYPE_CODE_METHOD: | |
188 | case TYPE_CODE_COMPLEX: | |
189 | default: | |
190 | break; | |
191 | } | |
192 | ||
193 | return value_cast (type, arg); | |
194 | } | |
195 | ||
196 | /* Determine a function's address and its return type from its value. | |
197 | Calls error() if the function is not valid for calling. */ | |
198 | ||
199 | CORE_ADDR | |
200 | find_function_addr (struct value *function, struct type **retval_type) | |
201 | { | |
202 | struct type *ftype = check_typedef (value_type (function)); | |
203 | enum type_code code = TYPE_CODE (ftype); | |
204 | struct type *value_type = NULL; | |
205 | CORE_ADDR funaddr; | |
206 | ||
207 | /* If it's a member function, just look at the function | |
208 | part of it. */ | |
209 | ||
210 | /* Determine address to call. */ | |
211 | if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD) | |
212 | { | |
213 | funaddr = VALUE_ADDRESS (function); | |
214 | value_type = TYPE_TARGET_TYPE (ftype); | |
215 | } | |
216 | else if (code == TYPE_CODE_PTR) | |
217 | { | |
218 | funaddr = value_as_address (function); | |
219 | ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); | |
220 | if (TYPE_CODE (ftype) == TYPE_CODE_FUNC | |
221 | || TYPE_CODE (ftype) == TYPE_CODE_METHOD) | |
222 | { | |
223 | funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch, | |
224 | funaddr, | |
225 | ¤t_target); | |
226 | value_type = TYPE_TARGET_TYPE (ftype); | |
227 | } | |
228 | } | |
229 | else if (code == TYPE_CODE_INT) | |
230 | { | |
231 | /* Handle the case of functions lacking debugging info. | |
232 | Their values are characters since their addresses are char */ | |
233 | if (TYPE_LENGTH (ftype) == 1) | |
234 | funaddr = value_as_address (value_addr (function)); | |
235 | else | |
236 | { | |
237 | /* Handle function descriptors lacking debug info. */ | |
238 | int found_descriptor = 0; | |
239 | if (VALUE_LVAL (function) == lval_memory) | |
240 | { | |
241 | CORE_ADDR nfunaddr; | |
242 | funaddr = value_as_address (value_addr (function)); | |
243 | nfunaddr = funaddr; | |
244 | funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch, | |
245 | funaddr, | |
246 | ¤t_target); | |
247 | if (funaddr != nfunaddr) | |
248 | found_descriptor = 1; | |
249 | } | |
250 | if (!found_descriptor) | |
251 | /* Handle integer used as address of a function. */ | |
252 | funaddr = (CORE_ADDR) value_as_long (function); | |
253 | } | |
254 | } | |
255 | else | |
256 | error (_("Invalid data type for function to be called.")); | |
257 | ||
258 | if (retval_type != NULL) | |
259 | *retval_type = value_type; | |
260 | return funaddr + gdbarch_deprecated_function_start_offset (current_gdbarch); | |
261 | } | |
262 | ||
263 | /* Call breakpoint_auto_delete on the current contents of the bpstat | |
264 | of the current thread. */ | |
265 | ||
266 | static void | |
267 | breakpoint_auto_delete_contents (void *arg) | |
268 | { | |
269 | if (!ptid_equal (inferior_ptid, null_ptid)) | |
270 | breakpoint_auto_delete (inferior_thread ()->stop_bpstat); | |
271 | } | |
272 | ||
273 | /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called | |
274 | function returns to. */ | |
275 | ||
276 | static CORE_ADDR | |
277 | push_dummy_code (struct gdbarch *gdbarch, | |
278 | CORE_ADDR sp, CORE_ADDR funaddr, | |
279 | struct value **args, int nargs, | |
280 | struct type *value_type, | |
281 | CORE_ADDR *real_pc, CORE_ADDR *bp_addr, | |
282 | struct regcache *regcache) | |
283 | { | |
284 | gdb_assert (gdbarch_push_dummy_code_p (gdbarch)); | |
285 | ||
286 | return gdbarch_push_dummy_code (gdbarch, sp, funaddr, | |
287 | args, nargs, value_type, real_pc, bp_addr, | |
288 | regcache); | |
289 | } | |
290 | ||
291 | /* All this stuff with a dummy frame may seem unnecessarily complicated | |
292 | (why not just save registers in GDB?). The purpose of pushing a dummy | |
293 | frame which looks just like a real frame is so that if you call a | |
294 | function and then hit a breakpoint (get a signal, etc), "backtrace" | |
295 | will look right. Whether the backtrace needs to actually show the | |
296 | stack at the time the inferior function was called is debatable, but | |
297 | it certainly needs to not display garbage. So if you are contemplating | |
298 | making dummy frames be different from normal frames, consider that. */ | |
299 | ||
300 | /* Perform a function call in the inferior. | |
301 | ARGS is a vector of values of arguments (NARGS of them). | |
302 | FUNCTION is a value, the function to be called. | |
303 | Returns a value representing what the function returned. | |
304 | May fail to return, if a breakpoint or signal is hit | |
305 | during the execution of the function. | |
306 | ||
307 | ARGS is modified to contain coerced values. */ | |
308 | ||
309 | struct value * | |
310 | call_function_by_hand (struct value *function, int nargs, struct value **args) | |
311 | { | |
312 | CORE_ADDR sp; | |
313 | CORE_ADDR dummy_addr; | |
314 | struct type *values_type, *target_values_type; | |
315 | unsigned char struct_return = 0, lang_struct_return = 0; | |
316 | CORE_ADDR struct_addr = 0; | |
317 | struct regcache *retbuf; | |
318 | struct cleanup *retbuf_cleanup; | |
319 | struct inferior_status *inf_status; | |
320 | struct cleanup *inf_status_cleanup; | |
321 | CORE_ADDR funaddr; | |
322 | CORE_ADDR real_pc; | |
323 | struct type *ftype = check_typedef (value_type (function)); | |
324 | CORE_ADDR bp_addr; | |
325 | struct regcache *caller_regcache; | |
326 | struct cleanup *caller_regcache_cleanup; | |
327 | struct frame_id dummy_id; | |
328 | struct cleanup *args_cleanup; | |
329 | struct frame_info *frame; | |
330 | struct gdbarch *gdbarch; | |
331 | ||
332 | if (TYPE_CODE (ftype) == TYPE_CODE_PTR) | |
333 | ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); | |
334 | ||
335 | if (!target_has_execution) | |
336 | noprocess (); | |
337 | ||
338 | frame = get_current_frame (); | |
339 | gdbarch = get_frame_arch (frame); | |
340 | ||
341 | if (!gdbarch_push_dummy_call_p (gdbarch)) | |
342 | error (_("This target does not support function calls")); | |
343 | ||
344 | /* Create a cleanup chain that contains the retbuf (buffer | |
345 | containing the register values). This chain is create BEFORE the | |
346 | inf_status chain so that the inferior status can cleaned up | |
347 | (restored or discarded) without having the retbuf freed. */ | |
348 | retbuf = regcache_xmalloc (gdbarch); | |
349 | retbuf_cleanup = make_cleanup_regcache_xfree (retbuf); | |
350 | ||
351 | /* A cleanup for the inferior status. Create this AFTER the retbuf | |
352 | so that this can be discarded or applied without interfering with | |
353 | the regbuf. */ | |
354 | inf_status = save_inferior_status (1); | |
355 | inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status); | |
356 | ||
357 | /* Save the caller's registers so that they can be restored once the | |
358 | callee returns. To allow nested calls the registers are (further | |
359 | down) pushed onto a dummy frame stack. Include a cleanup (which | |
360 | is tossed once the regcache has been pushed). */ | |
361 | caller_regcache = frame_save_as_regcache (frame); | |
362 | caller_regcache_cleanup = make_cleanup_regcache_xfree (caller_regcache); | |
363 | ||
364 | /* Ensure that the initial SP is correctly aligned. */ | |
365 | { | |
366 | CORE_ADDR old_sp = get_frame_sp (frame); | |
367 | if (gdbarch_frame_align_p (gdbarch)) | |
368 | { | |
369 | sp = gdbarch_frame_align (gdbarch, old_sp); | |
370 | /* NOTE: cagney/2003-08-13: Skip the "red zone". For some | |
371 | ABIs, a function can use memory beyond the inner most stack | |
372 | address. AMD64 called that region the "red zone". Skip at | |
373 | least the "red zone" size before allocating any space on | |
374 | the stack. */ | |
375 | if (gdbarch_inner_than (gdbarch, 1, 2)) | |
376 | sp -= gdbarch_frame_red_zone_size (gdbarch); | |
377 | else | |
378 | sp += gdbarch_frame_red_zone_size (gdbarch); | |
379 | /* Still aligned? */ | |
380 | gdb_assert (sp == gdbarch_frame_align (gdbarch, sp)); | |
381 | /* NOTE: cagney/2002-09-18: | |
382 | ||
383 | On a RISC architecture, a void parameterless generic dummy | |
384 | frame (i.e., no parameters, no result) typically does not | |
385 | need to push anything the stack and hence can leave SP and | |
386 | FP. Similarly, a frameless (possibly leaf) function does | |
387 | not push anything on the stack and, hence, that too can | |
388 | leave FP and SP unchanged. As a consequence, a sequence of | |
389 | void parameterless generic dummy frame calls to frameless | |
390 | functions will create a sequence of effectively identical | |
391 | frames (SP, FP and TOS and PC the same). This, not | |
392 | suprisingly, results in what appears to be a stack in an | |
393 | infinite loop --- when GDB tries to find a generic dummy | |
394 | frame on the internal dummy frame stack, it will always | |
395 | find the first one. | |
396 | ||
397 | To avoid this problem, the code below always grows the | |
398 | stack. That way, two dummy frames can never be identical. | |
399 | It does burn a few bytes of stack but that is a small price | |
400 | to pay :-). */ | |
401 | if (sp == old_sp) | |
402 | { | |
403 | if (gdbarch_inner_than (gdbarch, 1, 2)) | |
404 | /* Stack grows down. */ | |
405 | sp = gdbarch_frame_align (gdbarch, old_sp - 1); | |
406 | else | |
407 | /* Stack grows up. */ | |
408 | sp = gdbarch_frame_align (gdbarch, old_sp + 1); | |
409 | } | |
410 | gdb_assert ((gdbarch_inner_than (gdbarch, 1, 2) | |
411 | && sp <= old_sp) | |
412 | || (gdbarch_inner_than (gdbarch, 2, 1) | |
413 | && sp >= old_sp)); | |
414 | } | |
415 | else | |
416 | /* FIXME: cagney/2002-09-18: Hey, you loose! | |
417 | ||
418 | Who knows how badly aligned the SP is! | |
419 | ||
420 | If the generic dummy frame ends up empty (because nothing is | |
421 | pushed) GDB won't be able to correctly perform back traces. | |
422 | If a target is having trouble with backtraces, first thing to | |
423 | do is add FRAME_ALIGN() to the architecture vector. If that | |
424 | fails, try dummy_id(). | |
425 | ||
426 | If the ABI specifies a "Red Zone" (see the doco) the code | |
427 | below will quietly trash it. */ | |
428 | sp = old_sp; | |
429 | } | |
430 | ||
431 | funaddr = find_function_addr (function, &values_type); | |
432 | if (!values_type) | |
433 | values_type = builtin_type (gdbarch)->builtin_int; | |
434 | ||
435 | CHECK_TYPEDEF (values_type); | |
436 | ||
437 | /* Are we returning a value using a structure return (passing a | |
438 | hidden argument pointing to storage) or a normal value return? | |
439 | There are two cases: language-mandated structure return and | |
440 | target ABI structure return. The variable STRUCT_RETURN only | |
441 | describes the latter. The language version is handled by passing | |
442 | the return location as the first parameter to the function, | |
443 | even preceding "this". This is different from the target | |
444 | ABI version, which is target-specific; for instance, on ia64 | |
445 | the first argument is passed in out0 but the hidden structure | |
446 | return pointer would normally be passed in r8. */ | |
447 | ||
448 | if (language_pass_by_reference (values_type)) | |
449 | { | |
450 | lang_struct_return = 1; | |
451 | ||
452 | /* Tell the target specific argument pushing routine not to | |
453 | expect a value. */ | |
454 | target_values_type = builtin_type_void; | |
455 | } | |
456 | else | |
457 | { | |
458 | struct_return = using_struct_return (value_type (function), values_type); | |
459 | target_values_type = values_type; | |
460 | } | |
461 | ||
462 | /* Determine the location of the breakpoint (and possibly other | |
463 | stuff) that the called function will return to. The SPARC, for a | |
464 | function returning a structure or union, needs to make space for | |
465 | not just the breakpoint but also an extra word containing the | |
466 | size (?) of the structure being passed. */ | |
467 | ||
468 | /* The actual breakpoint (at BP_ADDR) is inserted separatly so there | |
469 | is no need to write that out. */ | |
470 | ||
471 | switch (gdbarch_call_dummy_location (gdbarch)) | |
472 | { | |
473 | case ON_STACK: | |
474 | /* "dummy_addr" is here just to keep old targets happy. New | |
475 | targets return that same information via "sp" and "bp_addr". */ | |
476 | if (gdbarch_inner_than (gdbarch, 1, 2)) | |
477 | { | |
478 | sp = push_dummy_code (gdbarch, sp, funaddr, | |
479 | args, nargs, target_values_type, | |
480 | &real_pc, &bp_addr, get_current_regcache ()); | |
481 | dummy_addr = sp; | |
482 | } | |
483 | else | |
484 | { | |
485 | dummy_addr = sp; | |
486 | sp = push_dummy_code (gdbarch, sp, funaddr, | |
487 | args, nargs, target_values_type, | |
488 | &real_pc, &bp_addr, get_current_regcache ()); | |
489 | } | |
490 | break; | |
491 | case AT_ENTRY_POINT: | |
492 | real_pc = funaddr; | |
493 | dummy_addr = entry_point_address (); | |
494 | /* Make certain that the address points at real code, and not a | |
495 | function descriptor. */ | |
496 | dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch, | |
497 | dummy_addr, | |
498 | ¤t_target); | |
499 | /* A call dummy always consists of just a single breakpoint, so | |
500 | it's address is the same as the address of the dummy. */ | |
501 | bp_addr = dummy_addr; | |
502 | break; | |
503 | case AT_SYMBOL: | |
504 | /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose | |
505 | address is the location where the breakpoint should be | |
506 | placed. Once all targets are using the overhauled frame code | |
507 | this can be deleted - ON_STACK is a better option. */ | |
508 | { | |
509 | struct minimal_symbol *sym; | |
510 | ||
511 | sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL, NULL); | |
512 | real_pc = funaddr; | |
513 | if (sym) | |
514 | dummy_addr = SYMBOL_VALUE_ADDRESS (sym); | |
515 | else | |
516 | dummy_addr = entry_point_address (); | |
517 | /* Make certain that the address points at real code, and not | |
518 | a function descriptor. */ | |
519 | dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch, | |
520 | dummy_addr, | |
521 | ¤t_target); | |
522 | /* A call dummy always consists of just a single breakpoint, | |
523 | so it's address is the same as the address of the dummy. */ | |
524 | bp_addr = dummy_addr; | |
525 | break; | |
526 | } | |
527 | default: | |
528 | internal_error (__FILE__, __LINE__, _("bad switch")); | |
529 | } | |
530 | ||
531 | if (nargs < TYPE_NFIELDS (ftype)) | |
532 | error (_("too few arguments in function call")); | |
533 | ||
534 | { | |
535 | int i; | |
536 | for (i = nargs - 1; i >= 0; i--) | |
537 | { | |
538 | int prototyped; | |
539 | struct type *param_type; | |
540 | ||
541 | /* FIXME drow/2002-05-31: Should just always mark methods as | |
542 | prototyped. Can we respect TYPE_VARARGS? Probably not. */ | |
543 | if (TYPE_CODE (ftype) == TYPE_CODE_METHOD) | |
544 | prototyped = 1; | |
545 | else if (i < TYPE_NFIELDS (ftype)) | |
546 | prototyped = TYPE_PROTOTYPED (ftype); | |
547 | else | |
548 | prototyped = 0; | |
549 | ||
550 | if (i < TYPE_NFIELDS (ftype)) | |
551 | param_type = TYPE_FIELD_TYPE (ftype, i); | |
552 | else | |
553 | param_type = NULL; | |
554 | ||
555 | args[i] = value_arg_coerce (gdbarch, args[i], | |
556 | param_type, prototyped, &sp); | |
557 | ||
558 | if (param_type != NULL && language_pass_by_reference (param_type)) | |
559 | args[i] = value_addr (args[i]); | |
560 | } | |
561 | } | |
562 | ||
563 | /* Reserve space for the return structure to be written on the | |
564 | stack, if necessary. Make certain that the value is correctly | |
565 | aligned. */ | |
566 | ||
567 | if (struct_return || lang_struct_return) | |
568 | { | |
569 | int len = TYPE_LENGTH (values_type); | |
570 | if (gdbarch_inner_than (gdbarch, 1, 2)) | |
571 | { | |
572 | /* Stack grows downward. Align STRUCT_ADDR and SP after | |
573 | making space for the return value. */ | |
574 | sp -= len; | |
575 | if (gdbarch_frame_align_p (gdbarch)) | |
576 | sp = gdbarch_frame_align (gdbarch, sp); | |
577 | struct_addr = sp; | |
578 | } | |
579 | else | |
580 | { | |
581 | /* Stack grows upward. Align the frame, allocate space, and | |
582 | then again, re-align the frame??? */ | |
583 | if (gdbarch_frame_align_p (gdbarch)) | |
584 | sp = gdbarch_frame_align (gdbarch, sp); | |
585 | struct_addr = sp; | |
586 | sp += len; | |
587 | if (gdbarch_frame_align_p (gdbarch)) | |
588 | sp = gdbarch_frame_align (gdbarch, sp); | |
589 | } | |
590 | } | |
591 | ||
592 | if (lang_struct_return) | |
593 | { | |
594 | struct value **new_args; | |
595 | ||
596 | /* Add the new argument to the front of the argument list. */ | |
597 | new_args = xmalloc (sizeof (struct value *) * (nargs + 1)); | |
598 | new_args[0] = value_from_pointer (lookup_pointer_type (values_type), | |
599 | struct_addr); | |
600 | memcpy (&new_args[1], &args[0], sizeof (struct value *) * nargs); | |
601 | args = new_args; | |
602 | nargs++; | |
603 | args_cleanup = make_cleanup (xfree, args); | |
604 | } | |
605 | else | |
606 | args_cleanup = make_cleanup (null_cleanup, NULL); | |
607 | ||
608 | /* Create the dummy stack frame. Pass in the call dummy address as, | |
609 | presumably, the ABI code knows where, in the call dummy, the | |
610 | return address should be pointed. */ | |
611 | sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (), | |
612 | bp_addr, nargs, args, | |
613 | sp, struct_return, struct_addr); | |
614 | ||
615 | do_cleanups (args_cleanup); | |
616 | ||
617 | /* Set up a frame ID for the dummy frame so we can pass it to | |
618 | set_momentary_breakpoint. We need to give the breakpoint a frame | |
619 | ID so that the breakpoint code can correctly re-identify the | |
620 | dummy breakpoint. */ | |
621 | /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL, | |
622 | saved as the dummy-frame TOS, and used by dummy_id to form | |
623 | the frame ID's stack address. */ | |
624 | dummy_id = frame_id_build (sp, bp_addr); | |
625 | ||
626 | /* Create a momentary breakpoint at the return address of the | |
627 | inferior. That way it breaks when it returns. */ | |
628 | ||
629 | { | |
630 | struct breakpoint *bpt; | |
631 | struct symtab_and_line sal; | |
632 | init_sal (&sal); /* initialize to zeroes */ | |
633 | sal.pc = bp_addr; | |
634 | sal.section = find_pc_overlay (sal.pc); | |
635 | /* Sanity. The exact same SP value is returned by | |
636 | PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by | |
637 | dummy_id to form the frame ID's stack address. */ | |
638 | bpt = set_momentary_breakpoint (sal, dummy_id, bp_call_dummy); | |
639 | bpt->disposition = disp_del; | |
640 | } | |
641 | ||
642 | /* Everything's ready, push all the info needed to restore the | |
643 | caller (and identify the dummy-frame) onto the dummy-frame | |
644 | stack. */ | |
645 | dummy_frame_push (caller_regcache, &dummy_id); | |
646 | discard_cleanups (caller_regcache_cleanup); | |
647 | ||
648 | /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - | |
649 | If you're looking to implement asynchronous dummy-frames, then | |
650 | just below is the place to chop this function in two.. */ | |
651 | ||
652 | /* Now proceed, having reached the desired place. */ | |
653 | clear_proceed_status (); | |
654 | ||
655 | /* Execute a "stack dummy", a piece of code stored in the stack by | |
656 | the debugger to be executed in the inferior. | |
657 | ||
658 | The dummy's frame is automatically popped whenever that break is | |
659 | hit. If that is the first time the program stops, | |
660 | call_function_by_hand returns to its caller with that frame | |
661 | already gone and sets RC to 0. | |
662 | ||
663 | Otherwise, set RC to a non-zero value. If the called function | |
664 | receives a random signal, we do not allow the user to continue | |
665 | executing it as this may not work. The dummy frame is poped and | |
666 | we return 1. If we hit a breakpoint, we leave the frame in place | |
667 | and return 2 (the frame will eventually be popped when we do hit | |
668 | the dummy end breakpoint). */ | |
669 | ||
670 | { | |
671 | struct cleanup *old_cleanups = make_cleanup (null_cleanup, 0); | |
672 | struct cleanup *old_cleanups2; | |
673 | int saved_async = 0; | |
674 | struct thread_info *tp = inferior_thread (); | |
675 | ||
676 | /* If all error()s out of proceed ended up calling normal_stop | |
677 | (and perhaps they should; it already does in the special case | |
678 | of error out of resume()), then we wouldn't need this. */ | |
679 | make_cleanup (breakpoint_auto_delete_contents, NULL); | |
680 | ||
681 | disable_watchpoints_before_interactive_call_start (); | |
682 | tp->proceed_to_finish = 1; /* We want stop_registers, please... */ | |
683 | ||
684 | if (target_can_async_p ()) | |
685 | saved_async = target_async_mask (0); | |
686 | ||
687 | old_cleanups2 = make_cleanup_restore_integer (&suppress_resume_observer); | |
688 | suppress_resume_observer = 1; | |
689 | make_cleanup_restore_integer (&suppress_stop_observer); | |
690 | suppress_stop_observer = 1; | |
691 | proceed (real_pc, TARGET_SIGNAL_0, 0); | |
692 | do_cleanups (old_cleanups2); | |
693 | ||
694 | if (saved_async) | |
695 | target_async_mask (saved_async); | |
696 | ||
697 | enable_watchpoints_after_interactive_call_stop (); | |
698 | ||
699 | discard_cleanups (old_cleanups); | |
700 | } | |
701 | ||
702 | if (! target_has_execution) | |
703 | { | |
704 | /* If we try to restore the inferior status (via the cleanup), | |
705 | we'll crash as the inferior is no longer running. */ | |
706 | discard_cleanups (inf_status_cleanup); | |
707 | discard_inferior_status (inf_status); | |
708 | error (_("\ | |
709 | The program being debugged exited while in a function called from GDB.")); | |
710 | } | |
711 | ||
712 | if (stopped_by_random_signal || !stop_stack_dummy) | |
713 | { | |
714 | /* Find the name of the function we're about to complain about. */ | |
715 | const char *name = NULL; | |
716 | { | |
717 | struct symbol *symbol = find_pc_function (funaddr); | |
718 | if (symbol) | |
719 | name = SYMBOL_PRINT_NAME (symbol); | |
720 | else | |
721 | { | |
722 | /* Try the minimal symbols. */ | |
723 | struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr); | |
724 | if (msymbol) | |
725 | name = SYMBOL_PRINT_NAME (msymbol); | |
726 | } | |
727 | if (name == NULL) | |
728 | { | |
729 | /* Can't use a cleanup here. It is discarded, instead use | |
730 | an alloca. */ | |
731 | char *tmp = xstrprintf ("at %s", hex_string (funaddr)); | |
732 | char *a = alloca (strlen (tmp) + 1); | |
733 | strcpy (a, tmp); | |
734 | xfree (tmp); | |
735 | name = a; | |
736 | } | |
737 | } | |
738 | if (stopped_by_random_signal) | |
739 | { | |
740 | /* We stopped inside the FUNCTION because of a random | |
741 | signal. Further execution of the FUNCTION is not | |
742 | allowed. */ | |
743 | ||
744 | if (unwind_on_signal_p) | |
745 | { | |
746 | /* The user wants the context restored. */ | |
747 | ||
748 | /* We must get back to the frame we were before the | |
749 | dummy call. */ | |
750 | frame_pop (get_current_frame ()); | |
751 | ||
752 | /* FIXME: Insert a bunch of wrap_here; name can be very | |
753 | long if it's a C++ name with arguments and stuff. */ | |
754 | error (_("\ | |
755 | The program being debugged was signaled while in a function called from GDB.\n\ | |
756 | GDB has restored the context to what it was before the call.\n\ | |
757 | To change this behavior use \"set unwindonsignal off\"\n\ | |
758 | Evaluation of the expression containing the function (%s) will be abandoned."), | |
759 | name); | |
760 | } | |
761 | else | |
762 | { | |
763 | /* The user wants to stay in the frame where we stopped | |
764 | (default).*/ | |
765 | /* If we restored the inferior status (via the cleanup), | |
766 | we would print a spurious error message (Unable to | |
767 | restore previously selected frame), would write the | |
768 | registers from the inf_status (which is wrong), and | |
769 | would do other wrong things. */ | |
770 | discard_cleanups (inf_status_cleanup); | |
771 | discard_inferior_status (inf_status); | |
772 | /* FIXME: Insert a bunch of wrap_here; name can be very | |
773 | long if it's a C++ name with arguments and stuff. */ | |
774 | error (_("\ | |
775 | The program being debugged was signaled while in a function called from GDB.\n\ | |
776 | GDB remains in the frame where the signal was received.\n\ | |
777 | To change this behavior use \"set unwindonsignal on\"\n\ | |
778 | Evaluation of the expression containing the function (%s) will be abandoned."), | |
779 | name); | |
780 | } | |
781 | } | |
782 | ||
783 | if (!stop_stack_dummy) | |
784 | { | |
785 | /* We hit a breakpoint inside the FUNCTION. */ | |
786 | /* If we restored the inferior status (via the cleanup), we | |
787 | would print a spurious error message (Unable to restore | |
788 | previously selected frame), would write the registers | |
789 | from the inf_status (which is wrong), and would do other | |
790 | wrong things. */ | |
791 | discard_cleanups (inf_status_cleanup); | |
792 | discard_inferior_status (inf_status); | |
793 | /* The following error message used to say "The expression | |
794 | which contained the function call has been discarded." | |
795 | It is a hard concept to explain in a few words. Ideally, | |
796 | GDB would be able to resume evaluation of the expression | |
797 | when the function finally is done executing. Perhaps | |
798 | someday this will be implemented (it would not be easy). */ | |
799 | /* FIXME: Insert a bunch of wrap_here; name can be very long if it's | |
800 | a C++ name with arguments and stuff. */ | |
801 | error (_("\ | |
802 | The program being debugged stopped while in a function called from GDB.\n\ | |
803 | When the function (%s) is done executing, GDB will silently\n\ | |
804 | stop (instead of continuing to evaluate the expression containing\n\ | |
805 | the function call)."), name); | |
806 | } | |
807 | ||
808 | /* The above code errors out, so ... */ | |
809 | internal_error (__FILE__, __LINE__, _("... should not be here")); | |
810 | } | |
811 | ||
812 | /* If we get here the called FUNCTION run to completion. */ | |
813 | ||
814 | /* On normal return, the stack dummy has been popped already. */ | |
815 | regcache_cpy_no_passthrough (retbuf, stop_registers); | |
816 | ||
817 | /* Restore the inferior status, via its cleanup. At this stage, | |
818 | leave the RETBUF alone. */ | |
819 | do_cleanups (inf_status_cleanup); | |
820 | ||
821 | /* Figure out the value returned by the function. */ | |
822 | { | |
823 | struct value *retval = NULL; | |
824 | ||
825 | if (lang_struct_return) | |
826 | retval = value_at (values_type, struct_addr); | |
827 | else if (TYPE_CODE (target_values_type) == TYPE_CODE_VOID) | |
828 | { | |
829 | /* If the function returns void, don't bother fetching the | |
830 | return value. */ | |
831 | retval = allocate_value (values_type); | |
832 | } | |
833 | else | |
834 | { | |
835 | switch (gdbarch_return_value (gdbarch, value_type (function), | |
836 | target_values_type, NULL, NULL, NULL)) | |
837 | { | |
838 | case RETURN_VALUE_REGISTER_CONVENTION: | |
839 | case RETURN_VALUE_ABI_RETURNS_ADDRESS: | |
840 | case RETURN_VALUE_ABI_PRESERVES_ADDRESS: | |
841 | retval = allocate_value (values_type); | |
842 | gdbarch_return_value (gdbarch, value_type (function), values_type, | |
843 | retbuf, value_contents_raw (retval), NULL); | |
844 | break; | |
845 | case RETURN_VALUE_STRUCT_CONVENTION: | |
846 | retval = value_at (values_type, struct_addr); | |
847 | break; | |
848 | } | |
849 | } | |
850 | ||
851 | do_cleanups (retbuf_cleanup); | |
852 | ||
853 | gdb_assert(retval); | |
854 | return retval; | |
855 | } | |
856 | } | |
857 | \f | |
858 | ||
859 | /* Provide a prototype to silence -Wmissing-prototypes. */ | |
860 | void _initialize_infcall (void); | |
861 | ||
862 | void | |
863 | _initialize_infcall (void) | |
864 | { | |
865 | add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure, | |
866 | &coerce_float_to_double_p, _("\ | |
867 | Set coercion of floats to doubles when calling functions."), _("\ | |
868 | Show coercion of floats to doubles when calling functions"), _("\ | |
869 | Variables of type float should generally be converted to doubles before\n\ | |
870 | calling an unprototyped function, and left alone when calling a prototyped\n\ | |
871 | function. However, some older debug info formats do not provide enough\n\ | |
872 | information to determine that a function is prototyped. If this flag is\n\ | |
873 | set, GDB will perform the conversion for a function it considers\n\ | |
874 | unprototyped.\n\ | |
875 | The default is to perform the conversion.\n"), | |
876 | NULL, | |
877 | show_coerce_float_to_double_p, | |
878 | &setlist, &showlist); | |
879 | ||
880 | add_setshow_boolean_cmd ("unwindonsignal", no_class, | |
881 | &unwind_on_signal_p, _("\ | |
882 | Set unwinding of stack if a signal is received while in a call dummy."), _("\ | |
883 | Show unwinding of stack if a signal is received while in a call dummy."), _("\ | |
884 | The unwindonsignal lets the user determine what gdb should do if a signal\n\ | |
885 | is received while in a function called from gdb (call dummy). If set, gdb\n\ | |
886 | unwinds the stack and restore the context to what as it was before the call.\n\ | |
887 | The default is to stop in the frame where the signal was received."), | |
888 | NULL, | |
889 | show_unwind_on_signal_p, | |
890 | &setlist, &showlist); | |
891 | } |