Commit | Line | Data |
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04714b91 AC |
1 | /* Perform an inferior function call, for GDB, the GNU debugger. |
2 | ||
6aba47ca | 3 | Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
9b254dd1 DJ |
4 | 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, |
5 | 2008 Free Software Foundation, Inc. | |
04714b91 AC |
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 | |
a9762ec7 | 11 | the Free Software Foundation; either version 3 of the License, or |
04714b91 AC |
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 | |
a9762ec7 | 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
04714b91 AC |
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" | |
9ab9195f | 31 | #include "objfiles.h" |
04714b91 AC |
32 | #include "gdbcmd.h" |
33 | #include "command.h" | |
34 | #include "gdb_string.h" | |
b9362cc7 | 35 | #include "infcall.h" |
96860204 | 36 | #include "dummy-frame.h" |
a93c0eb6 | 37 | #include "ada-lang.h" |
04714b91 AC |
38 | |
39 | /* NOTE: cagney/2003-04-16: What's the future of this code? | |
40 | ||
41 | GDB needs an asynchronous expression evaluator, that means an | |
42 | asynchronous inferior function call implementation, and that in | |
43 | turn means restructuring the code so that it is event driven. */ | |
44 | ||
45 | /* How you should pass arguments to a function depends on whether it | |
46 | was defined in K&R style or prototype style. If you define a | |
47 | function using the K&R syntax that takes a `float' argument, then | |
48 | callers must pass that argument as a `double'. If you define the | |
49 | function using the prototype syntax, then you must pass the | |
50 | argument as a `float', with no promotion. | |
51 | ||
52 | Unfortunately, on certain older platforms, the debug info doesn't | |
53 | indicate reliably how each function was defined. A function type's | |
54 | TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was | |
55 | defined in prototype style. When calling a function whose | |
56 | TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to | |
57 | decide what to do. | |
58 | ||
59 | For modern targets, it is proper to assume that, if the prototype | |
60 | flag is clear, that can be trusted: `float' arguments should be | |
61 | promoted to `double'. For some older targets, if the prototype | |
62 | flag is clear, that doesn't tell us anything. The default is to | |
63 | trust the debug information; the user can override this behavior | |
64 | with "set coerce-float-to-double 0". */ | |
65 | ||
66 | static int coerce_float_to_double_p = 1; | |
920d2a44 AC |
67 | static void |
68 | show_coerce_float_to_double_p (struct ui_file *file, int from_tty, | |
69 | struct cmd_list_element *c, const char *value) | |
70 | { | |
71 | fprintf_filtered (file, _("\ | |
72 | Coercion of floats to doubles when calling functions is %s.\n"), | |
73 | value); | |
74 | } | |
04714b91 AC |
75 | |
76 | /* This boolean tells what gdb should do if a signal is received while | |
77 | in a function called from gdb (call dummy). If set, gdb unwinds | |
78 | the stack and restore the context to what as it was before the | |
79 | call. | |
80 | ||
81 | The default is to stop in the frame where the signal was received. */ | |
82 | ||
83 | int unwind_on_signal_p = 0; | |
920d2a44 AC |
84 | static void |
85 | show_unwind_on_signal_p (struct ui_file *file, int from_tty, | |
86 | struct cmd_list_element *c, const char *value) | |
87 | { | |
88 | fprintf_filtered (file, _("\ | |
89 | Unwinding of stack if a signal is received while in a call dummy is %s.\n"), | |
90 | value); | |
91 | } | |
92 | ||
04714b91 AC |
93 | |
94 | /* Perform the standard coercions that are specified | |
a93c0eb6 | 95 | for arguments to be passed to C or Ada functions. |
04714b91 AC |
96 | |
97 | If PARAM_TYPE is non-NULL, it is the expected parameter type. | |
a93c0eb6 JB |
98 | IS_PROTOTYPED is non-zero if the function declaration is prototyped. |
99 | SP is the stack pointer were additional data can be pushed (updating | |
100 | its value as needed). */ | |
04714b91 AC |
101 | |
102 | static struct value * | |
103 | value_arg_coerce (struct value *arg, struct type *param_type, | |
a93c0eb6 | 104 | int is_prototyped, CORE_ADDR *sp) |
04714b91 | 105 | { |
df407dfe | 106 | struct type *arg_type = check_typedef (value_type (arg)); |
52f0bd74 | 107 | struct type *type |
04714b91 AC |
108 | = param_type ? check_typedef (param_type) : arg_type; |
109 | ||
a93c0eb6 JB |
110 | /* Perform any Ada-specific coercion first. */ |
111 | if (current_language->la_language == language_ada) | |
112 | arg = ada_convert_actual (arg, type, sp); | |
113 | ||
63092375 DJ |
114 | /* Force the value to the target if we will need its address. At |
115 | this point, we could allocate arguments on the stack instead of | |
116 | calling malloc if we knew that their addresses would not be | |
117 | saved by the called function. */ | |
118 | arg = value_coerce_to_target (arg); | |
119 | ||
04714b91 AC |
120 | switch (TYPE_CODE (type)) |
121 | { | |
122 | case TYPE_CODE_REF: | |
fb933624 DJ |
123 | { |
124 | struct value *new_value; | |
125 | ||
126 | if (TYPE_CODE (arg_type) == TYPE_CODE_REF) | |
127 | return value_cast_pointers (type, arg); | |
128 | ||
129 | /* Cast the value to the reference's target type, and then | |
130 | convert it back to a reference. This will issue an error | |
131 | if the value was not previously in memory - in some cases | |
132 | we should clearly be allowing this, but how? */ | |
133 | new_value = value_cast (TYPE_TARGET_TYPE (type), arg); | |
134 | new_value = value_ref (new_value); | |
135 | return new_value; | |
136 | } | |
04714b91 AC |
137 | case TYPE_CODE_INT: |
138 | case TYPE_CODE_CHAR: | |
139 | case TYPE_CODE_BOOL: | |
140 | case TYPE_CODE_ENUM: | |
141 | /* If we don't have a prototype, coerce to integer type if necessary. */ | |
142 | if (!is_prototyped) | |
143 | { | |
144 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int)) | |
145 | type = builtin_type_int; | |
146 | } | |
147 | /* Currently all target ABIs require at least the width of an integer | |
148 | type for an argument. We may have to conditionalize the following | |
149 | type coercion for future targets. */ | |
150 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int)) | |
151 | type = builtin_type_int; | |
152 | break; | |
153 | case TYPE_CODE_FLT: | |
154 | if (!is_prototyped && coerce_float_to_double_p) | |
155 | { | |
156 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_double)) | |
157 | type = builtin_type_double; | |
158 | else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin_type_double)) | |
159 | type = builtin_type_long_double; | |
160 | } | |
161 | break; | |
162 | case TYPE_CODE_FUNC: | |
163 | type = lookup_pointer_type (type); | |
164 | break; | |
165 | case TYPE_CODE_ARRAY: | |
166 | /* Arrays are coerced to pointers to their first element, unless | |
167 | they are vectors, in which case we want to leave them alone, | |
168 | because they are passed by value. */ | |
169 | if (current_language->c_style_arrays) | |
170 | if (!TYPE_VECTOR (type)) | |
171 | type = lookup_pointer_type (TYPE_TARGET_TYPE (type)); | |
172 | break; | |
173 | case TYPE_CODE_UNDEF: | |
174 | case TYPE_CODE_PTR: | |
175 | case TYPE_CODE_STRUCT: | |
176 | case TYPE_CODE_UNION: | |
177 | case TYPE_CODE_VOID: | |
178 | case TYPE_CODE_SET: | |
179 | case TYPE_CODE_RANGE: | |
180 | case TYPE_CODE_STRING: | |
181 | case TYPE_CODE_BITSTRING: | |
182 | case TYPE_CODE_ERROR: | |
0d5de010 DJ |
183 | case TYPE_CODE_MEMBERPTR: |
184 | case TYPE_CODE_METHODPTR: | |
04714b91 AC |
185 | case TYPE_CODE_METHOD: |
186 | case TYPE_CODE_COMPLEX: | |
187 | default: | |
188 | break; | |
189 | } | |
190 | ||
191 | return value_cast (type, arg); | |
192 | } | |
193 | ||
194 | /* Determine a function's address and its return type from its value. | |
195 | Calls error() if the function is not valid for calling. */ | |
196 | ||
a9fa03de | 197 | CORE_ADDR |
04714b91 AC |
198 | find_function_addr (struct value *function, struct type **retval_type) |
199 | { | |
df407dfe | 200 | struct type *ftype = check_typedef (value_type (function)); |
52f0bd74 | 201 | enum type_code code = TYPE_CODE (ftype); |
04714b91 AC |
202 | struct type *value_type; |
203 | CORE_ADDR funaddr; | |
204 | ||
205 | /* If it's a member function, just look at the function | |
206 | part of it. */ | |
207 | ||
208 | /* Determine address to call. */ | |
209 | if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD) | |
210 | { | |
211 | funaddr = VALUE_ADDRESS (function); | |
212 | value_type = TYPE_TARGET_TYPE (ftype); | |
213 | } | |
214 | else if (code == TYPE_CODE_PTR) | |
215 | { | |
216 | funaddr = value_as_address (function); | |
217 | ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); | |
218 | if (TYPE_CODE (ftype) == TYPE_CODE_FUNC | |
219 | || TYPE_CODE (ftype) == TYPE_CODE_METHOD) | |
220 | { | |
e2d0e7eb AC |
221 | funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch, |
222 | funaddr, | |
223 | ¤t_target); | |
04714b91 AC |
224 | value_type = TYPE_TARGET_TYPE (ftype); |
225 | } | |
226 | else | |
227 | value_type = builtin_type_int; | |
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 | |
2bbe3cc1 DJ |
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 | } | |
04714b91 AC |
254 | |
255 | value_type = builtin_type_int; | |
256 | } | |
257 | else | |
8a3fe4f8 | 258 | error (_("Invalid data type for function to be called.")); |
04714b91 | 259 | |
7d9b040b RC |
260 | if (retval_type != NULL) |
261 | *retval_type = value_type; | |
cbf3b44a | 262 | return funaddr + gdbarch_deprecated_function_start_offset (current_gdbarch); |
04714b91 AC |
263 | } |
264 | ||
265 | /* Call breakpoint_auto_delete on the current contents of the bpstat | |
266 | pointed to by arg (which is really a bpstat *). */ | |
267 | ||
268 | static void | |
269 | breakpoint_auto_delete_contents (void *arg) | |
270 | { | |
271 | breakpoint_auto_delete (*(bpstat *) arg); | |
272 | } | |
273 | ||
7043d8dc AC |
274 | static CORE_ADDR |
275 | generic_push_dummy_code (struct gdbarch *gdbarch, | |
82585c72 | 276 | CORE_ADDR sp, CORE_ADDR funaddr, |
7043d8dc AC |
277 | struct value **args, int nargs, |
278 | struct type *value_type, | |
e4fd649a UW |
279 | CORE_ADDR *real_pc, CORE_ADDR *bp_addr, |
280 | struct regcache *regcache) | |
7043d8dc AC |
281 | { |
282 | /* Something here to findout the size of a breakpoint and then | |
283 | allocate space for it on the stack. */ | |
284 | int bplen; | |
285 | /* This code assumes frame align. */ | |
286 | gdb_assert (gdbarch_frame_align_p (gdbarch)); | |
287 | /* Force the stack's alignment. The intent is to ensure that the SP | |
288 | is aligned to at least a breakpoint instruction's boundary. */ | |
289 | sp = gdbarch_frame_align (gdbarch, sp); | |
290 | /* Allocate space for, and then position the breakpoint on the | |
291 | stack. */ | |
292 | if (gdbarch_inner_than (gdbarch, 1, 2)) | |
293 | { | |
294 | CORE_ADDR bppc = sp; | |
295 | gdbarch_breakpoint_from_pc (gdbarch, &bppc, &bplen); | |
296 | sp = gdbarch_frame_align (gdbarch, sp - bplen); | |
297 | (*bp_addr) = sp; | |
298 | /* Should the breakpoint size/location be re-computed here? */ | |
299 | } | |
300 | else | |
301 | { | |
302 | (*bp_addr) = sp; | |
303 | gdbarch_breakpoint_from_pc (gdbarch, bp_addr, &bplen); | |
304 | sp = gdbarch_frame_align (gdbarch, sp + bplen); | |
305 | } | |
306 | /* Inferior resumes at the function entry point. */ | |
307 | (*real_pc) = funaddr; | |
308 | return sp; | |
309 | } | |
310 | ||
d3712828 AC |
311 | /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called |
312 | function returns to. */ | |
7043d8dc AC |
313 | |
314 | static CORE_ADDR | |
315 | push_dummy_code (struct gdbarch *gdbarch, | |
82585c72 | 316 | CORE_ADDR sp, CORE_ADDR funaddr, |
7043d8dc AC |
317 | struct value **args, int nargs, |
318 | struct type *value_type, | |
e4fd649a UW |
319 | CORE_ADDR *real_pc, CORE_ADDR *bp_addr, |
320 | struct regcache *regcache) | |
7043d8dc AC |
321 | { |
322 | if (gdbarch_push_dummy_code_p (gdbarch)) | |
82585c72 | 323 | return gdbarch_push_dummy_code (gdbarch, sp, funaddr, |
e4fd649a UW |
324 | args, nargs, value_type, real_pc, bp_addr, |
325 | regcache); | |
7043d8dc | 326 | else |
82585c72 | 327 | return generic_push_dummy_code (gdbarch, sp, funaddr, |
e4fd649a UW |
328 | args, nargs, value_type, real_pc, bp_addr, |
329 | regcache); | |
7043d8dc AC |
330 | } |
331 | ||
04714b91 AC |
332 | /* All this stuff with a dummy frame may seem unnecessarily complicated |
333 | (why not just save registers in GDB?). The purpose of pushing a dummy | |
334 | frame which looks just like a real frame is so that if you call a | |
335 | function and then hit a breakpoint (get a signal, etc), "backtrace" | |
336 | will look right. Whether the backtrace needs to actually show the | |
337 | stack at the time the inferior function was called is debatable, but | |
338 | it certainly needs to not display garbage. So if you are contemplating | |
339 | making dummy frames be different from normal frames, consider that. */ | |
340 | ||
341 | /* Perform a function call in the inferior. | |
342 | ARGS is a vector of values of arguments (NARGS of them). | |
343 | FUNCTION is a value, the function to be called. | |
344 | Returns a value representing what the function returned. | |
345 | May fail to return, if a breakpoint or signal is hit | |
346 | during the execution of the function. | |
347 | ||
348 | ARGS is modified to contain coerced values. */ | |
349 | ||
350 | struct value * | |
351 | call_function_by_hand (struct value *function, int nargs, struct value **args) | |
352 | { | |
52f0bd74 | 353 | CORE_ADDR sp; |
04714b91 | 354 | CORE_ADDR dummy_addr; |
41f1b697 DJ |
355 | struct type *values_type, *target_values_type; |
356 | unsigned char struct_return = 0, lang_struct_return = 0; | |
04714b91 AC |
357 | CORE_ADDR struct_addr = 0; |
358 | struct regcache *retbuf; | |
359 | struct cleanup *retbuf_cleanup; | |
360 | struct inferior_status *inf_status; | |
361 | struct cleanup *inf_status_cleanup; | |
362 | CORE_ADDR funaddr; | |
04714b91 | 363 | CORE_ADDR real_pc; |
df407dfe | 364 | struct type *ftype = check_typedef (value_type (function)); |
d585e13a | 365 | CORE_ADDR bp_addr; |
96860204 AC |
366 | struct regcache *caller_regcache; |
367 | struct cleanup *caller_regcache_cleanup; | |
368 | struct frame_id dummy_id; | |
41f1b697 | 369 | struct cleanup *args_cleanup; |
0b9dfe2b MD |
370 | struct frame_info *frame; |
371 | struct gdbarch *gdbarch; | |
04714b91 | 372 | |
4c850810 DJ |
373 | if (TYPE_CODE (ftype) == TYPE_CODE_PTR) |
374 | ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); | |
375 | ||
04714b91 AC |
376 | if (!target_has_execution) |
377 | noprocess (); | |
378 | ||
0b9dfe2b MD |
379 | frame = get_current_frame (); |
380 | gdbarch = get_frame_arch (frame); | |
381 | ||
382 | if (!gdbarch_push_dummy_call_p (gdbarch)) | |
a86c5fc9 MK |
383 | error (_("This target does not support function calls")); |
384 | ||
04714b91 AC |
385 | /* Create a cleanup chain that contains the retbuf (buffer |
386 | containing the register values). This chain is create BEFORE the | |
387 | inf_status chain so that the inferior status can cleaned up | |
388 | (restored or discarded) without having the retbuf freed. */ | |
0b9dfe2b | 389 | retbuf = regcache_xmalloc (gdbarch); |
04714b91 AC |
390 | retbuf_cleanup = make_cleanup_regcache_xfree (retbuf); |
391 | ||
392 | /* A cleanup for the inferior status. Create this AFTER the retbuf | |
393 | so that this can be discarded or applied without interfering with | |
394 | the regbuf. */ | |
395 | inf_status = save_inferior_status (1); | |
396 | inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status); | |
397 | ||
96860204 AC |
398 | /* Save the caller's registers so that they can be restored once the |
399 | callee returns. To allow nested calls the registers are (further | |
400 | down) pushed onto a dummy frame stack. Include a cleanup (which | |
401 | is tossed once the regcache has been pushed). */ | |
0b9dfe2b | 402 | caller_regcache = frame_save_as_regcache (frame); |
96860204 | 403 | caller_regcache_cleanup = make_cleanup_regcache_xfree (caller_regcache); |
04714b91 | 404 | |
04714b91 | 405 | /* Ensure that the initial SP is correctly aligned. */ |
ebc7896c | 406 | { |
0b9dfe2b MD |
407 | CORE_ADDR old_sp = get_frame_sp (frame); |
408 | if (gdbarch_frame_align_p (gdbarch)) | |
ebc7896c | 409 | { |
0b9dfe2b | 410 | sp = gdbarch_frame_align (gdbarch, old_sp); |
8b148df9 AC |
411 | /* NOTE: cagney/2003-08-13: Skip the "red zone". For some |
412 | ABIs, a function can use memory beyond the inner most stack | |
413 | address. AMD64 called that region the "red zone". Skip at | |
414 | least the "red zone" size before allocating any space on | |
415 | the stack. */ | |
0b9dfe2b MD |
416 | if (gdbarch_inner_than (gdbarch, 1, 2)) |
417 | sp -= gdbarch_frame_red_zone_size (gdbarch); | |
8b148df9 | 418 | else |
0b9dfe2b | 419 | sp += gdbarch_frame_red_zone_size (gdbarch); |
8b148df9 | 420 | /* Still aligned? */ |
0b9dfe2b | 421 | gdb_assert (sp == gdbarch_frame_align (gdbarch, sp)); |
ebc7896c AC |
422 | /* NOTE: cagney/2002-09-18: |
423 | ||
424 | On a RISC architecture, a void parameterless generic dummy | |
425 | frame (i.e., no parameters, no result) typically does not | |
426 | need to push anything the stack and hence can leave SP and | |
c48a845b | 427 | FP. Similarly, a frameless (possibly leaf) function does |
ebc7896c AC |
428 | not push anything on the stack and, hence, that too can |
429 | leave FP and SP unchanged. As a consequence, a sequence of | |
430 | void parameterless generic dummy frame calls to frameless | |
431 | functions will create a sequence of effectively identical | |
432 | frames (SP, FP and TOS and PC the same). This, not | |
433 | suprisingly, results in what appears to be a stack in an | |
434 | infinite loop --- when GDB tries to find a generic dummy | |
435 | frame on the internal dummy frame stack, it will always | |
436 | find the first one. | |
437 | ||
438 | To avoid this problem, the code below always grows the | |
439 | stack. That way, two dummy frames can never be identical. | |
440 | It does burn a few bytes of stack but that is a small price | |
441 | to pay :-). */ | |
ebc7896c AC |
442 | if (sp == old_sp) |
443 | { | |
0b9dfe2b | 444 | if (gdbarch_inner_than (gdbarch, 1, 2)) |
ebc7896c | 445 | /* Stack grows down. */ |
0b9dfe2b | 446 | sp = gdbarch_frame_align (gdbarch, old_sp - 1); |
ebc7896c AC |
447 | else |
448 | /* Stack grows up. */ | |
0b9dfe2b | 449 | sp = gdbarch_frame_align (gdbarch, old_sp + 1); |
ebc7896c | 450 | } |
0b9dfe2b | 451 | gdb_assert ((gdbarch_inner_than (gdbarch, 1, 2) |
4d1e7dd1 | 452 | && sp <= old_sp) |
0b9dfe2b | 453 | || (gdbarch_inner_than (gdbarch, 2, 1) |
4d1e7dd1 | 454 | && sp >= old_sp)); |
ebc7896c AC |
455 | } |
456 | else | |
a59fe496 AC |
457 | /* FIXME: cagney/2002-09-18: Hey, you loose! |
458 | ||
8b148df9 AC |
459 | Who knows how badly aligned the SP is! |
460 | ||
461 | If the generic dummy frame ends up empty (because nothing is | |
462 | pushed) GDB won't be able to correctly perform back traces. | |
463 | If a target is having trouble with backtraces, first thing to | |
464 | do is add FRAME_ALIGN() to the architecture vector. If that | |
669fac23 | 465 | fails, try dummy_id(). |
8b148df9 AC |
466 | |
467 | If the ABI specifies a "Red Zone" (see the doco) the code | |
468 | below will quietly trash it. */ | |
ebc7896c AC |
469 | sp = old_sp; |
470 | } | |
04714b91 | 471 | |
df407dfe AC |
472 | funaddr = find_function_addr (function, &values_type); |
473 | CHECK_TYPEDEF (values_type); | |
04714b91 | 474 | |
41f1b697 DJ |
475 | /* Are we returning a value using a structure return (passing a |
476 | hidden argument pointing to storage) or a normal value return? | |
477 | There are two cases: language-mandated structure return and | |
478 | target ABI structure return. The variable STRUCT_RETURN only | |
479 | describes the latter. The language version is handled by passing | |
480 | the return location as the first parameter to the function, | |
481 | even preceding "this". This is different from the target | |
482 | ABI version, which is target-specific; for instance, on ia64 | |
483 | the first argument is passed in out0 but the hidden structure | |
484 | return pointer would normally be passed in r8. */ | |
485 | ||
486 | if (language_pass_by_reference (values_type)) | |
487 | { | |
488 | lang_struct_return = 1; | |
04714b91 | 489 | |
41f1b697 DJ |
490 | /* Tell the target specific argument pushing routine not to |
491 | expect a value. */ | |
492 | target_values_type = builtin_type_void; | |
493 | } | |
494 | else | |
495 | { | |
c055b101 | 496 | struct_return = using_struct_return (value_type (function), values_type); |
41f1b697 DJ |
497 | target_values_type = values_type; |
498 | } | |
04714b91 | 499 | |
7043d8dc AC |
500 | /* Determine the location of the breakpoint (and possibly other |
501 | stuff) that the called function will return to. The SPARC, for a | |
502 | function returning a structure or union, needs to make space for | |
503 | not just the breakpoint but also an extra word containing the | |
504 | size (?) of the structure being passed. */ | |
505 | ||
506 | /* The actual breakpoint (at BP_ADDR) is inserted separatly so there | |
507 | is no need to write that out. */ | |
508 | ||
0b9dfe2b | 509 | switch (gdbarch_call_dummy_location (gdbarch)) |
04714b91 AC |
510 | { |
511 | case ON_STACK: | |
7043d8dc AC |
512 | /* "dummy_addr" is here just to keep old targets happy. New |
513 | targets return that same information via "sp" and "bp_addr". */ | |
0b9dfe2b | 514 | if (gdbarch_inner_than (gdbarch, 1, 2)) |
d585e13a | 515 | { |
0b9dfe2b | 516 | sp = push_dummy_code (gdbarch, sp, funaddr, |
82585c72 | 517 | args, nargs, target_values_type, |
594f7785 | 518 | &real_pc, &bp_addr, get_current_regcache ()); |
7043d8dc | 519 | dummy_addr = sp; |
d585e13a | 520 | } |
7043d8dc AC |
521 | else |
522 | { | |
523 | dummy_addr = sp; | |
0b9dfe2b | 524 | sp = push_dummy_code (gdbarch, sp, funaddr, |
82585c72 | 525 | args, nargs, target_values_type, |
594f7785 | 526 | &real_pc, &bp_addr, get_current_regcache ()); |
7043d8dc AC |
527 | } |
528 | break; | |
04714b91 AC |
529 | case AT_ENTRY_POINT: |
530 | real_pc = funaddr; | |
88a82a65 | 531 | dummy_addr = entry_point_address (); |
0285512f AC |
532 | /* Make certain that the address points at real code, and not a |
533 | function descriptor. */ | |
0b9dfe2b | 534 | dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch, |
e2d0e7eb AC |
535 | dummy_addr, |
536 | ¤t_target); | |
d585e13a AC |
537 | /* A call dummy always consists of just a single breakpoint, so |
538 | it's address is the same as the address of the dummy. */ | |
539 | bp_addr = dummy_addr; | |
04714b91 | 540 | break; |
9710e734 AC |
541 | case AT_SYMBOL: |
542 | /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose | |
543 | address is the location where the breakpoint should be | |
544 | placed. Once all targets are using the overhauled frame code | |
545 | this can be deleted - ON_STACK is a better option. */ | |
546 | { | |
547 | struct minimal_symbol *sym; | |
548 | ||
549 | sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL, NULL); | |
550 | real_pc = funaddr; | |
551 | if (sym) | |
552 | dummy_addr = SYMBOL_VALUE_ADDRESS (sym); | |
553 | else | |
554 | dummy_addr = entry_point_address (); | |
0285512f AC |
555 | /* Make certain that the address points at real code, and not |
556 | a function descriptor. */ | |
0b9dfe2b | 557 | dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch, |
e2d0e7eb AC |
558 | dummy_addr, |
559 | ¤t_target); | |
0285512f AC |
560 | /* A call dummy always consists of just a single breakpoint, |
561 | so it's address is the same as the address of the dummy. */ | |
9710e734 AC |
562 | bp_addr = dummy_addr; |
563 | break; | |
564 | } | |
04714b91 | 565 | default: |
e2e0b3e5 | 566 | internal_error (__FILE__, __LINE__, _("bad switch")); |
04714b91 AC |
567 | } |
568 | ||
04714b91 | 569 | if (nargs < TYPE_NFIELDS (ftype)) |
8a3fe4f8 | 570 | error (_("too few arguments in function call")); |
04714b91 | 571 | |
ebc7896c AC |
572 | { |
573 | int i; | |
574 | for (i = nargs - 1; i >= 0; i--) | |
575 | { | |
576 | int prototyped; | |
577 | struct type *param_type; | |
578 | ||
579 | /* FIXME drow/2002-05-31: Should just always mark methods as | |
580 | prototyped. Can we respect TYPE_VARARGS? Probably not. */ | |
581 | if (TYPE_CODE (ftype) == TYPE_CODE_METHOD) | |
582 | prototyped = 1; | |
583 | else if (i < TYPE_NFIELDS (ftype)) | |
584 | prototyped = TYPE_PROTOTYPED (ftype); | |
585 | else | |
586 | prototyped = 0; | |
587 | ||
588 | if (i < TYPE_NFIELDS (ftype)) | |
589 | param_type = TYPE_FIELD_TYPE (ftype, i); | |
590 | else | |
591 | param_type = NULL; | |
41f1b697 | 592 | |
a93c0eb6 | 593 | args[i] = value_arg_coerce (args[i], param_type, prototyped, &sp); |
ebc7896c | 594 | |
41f1b697 DJ |
595 | if (param_type != NULL && language_pass_by_reference (param_type)) |
596 | args[i] = value_addr (args[i]); | |
ebc7896c AC |
597 | } |
598 | } | |
04714b91 | 599 | |
04714b91 AC |
600 | /* Reserve space for the return structure to be written on the |
601 | stack, if necessary. Make certain that the value is correctly | |
602 | aligned. */ | |
603 | ||
41f1b697 | 604 | if (struct_return || lang_struct_return) |
04714b91 | 605 | { |
df407dfe | 606 | int len = TYPE_LENGTH (values_type); |
0b9dfe2b | 607 | if (gdbarch_inner_than (gdbarch, 1, 2)) |
04714b91 AC |
608 | { |
609 | /* Stack grows downward. Align STRUCT_ADDR and SP after | |
610 | making space for the return value. */ | |
611 | sp -= len; | |
0b9dfe2b MD |
612 | if (gdbarch_frame_align_p (gdbarch)) |
613 | sp = gdbarch_frame_align (gdbarch, sp); | |
04714b91 AC |
614 | struct_addr = sp; |
615 | } | |
616 | else | |
617 | { | |
618 | /* Stack grows upward. Align the frame, allocate space, and | |
619 | then again, re-align the frame??? */ | |
0b9dfe2b MD |
620 | if (gdbarch_frame_align_p (gdbarch)) |
621 | sp = gdbarch_frame_align (gdbarch, sp); | |
04714b91 AC |
622 | struct_addr = sp; |
623 | sp += len; | |
0b9dfe2b MD |
624 | if (gdbarch_frame_align_p (gdbarch)) |
625 | sp = gdbarch_frame_align (gdbarch, sp); | |
04714b91 AC |
626 | } |
627 | } | |
628 | ||
41f1b697 DJ |
629 | if (lang_struct_return) |
630 | { | |
631 | struct value **new_args; | |
632 | ||
633 | /* Add the new argument to the front of the argument list. */ | |
634 | new_args = xmalloc (sizeof (struct value *) * (nargs + 1)); | |
635 | new_args[0] = value_from_pointer (lookup_pointer_type (values_type), | |
636 | struct_addr); | |
637 | memcpy (&new_args[1], &args[0], sizeof (struct value *) * nargs); | |
638 | args = new_args; | |
639 | nargs++; | |
640 | args_cleanup = make_cleanup (xfree, args); | |
641 | } | |
642 | else | |
643 | args_cleanup = make_cleanup (null_cleanup, NULL); | |
644 | ||
04714b91 AC |
645 | /* Create the dummy stack frame. Pass in the call dummy address as, |
646 | presumably, the ABI code knows where, in the call dummy, the | |
647 | return address should be pointed. */ | |
0b9dfe2b MD |
648 | sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (), |
649 | bp_addr, nargs, args, | |
594f7785 | 650 | sp, struct_return, struct_addr); |
04714b91 | 651 | |
41f1b697 DJ |
652 | do_cleanups (args_cleanup); |
653 | ||
96860204 AC |
654 | /* Set up a frame ID for the dummy frame so we can pass it to |
655 | set_momentary_breakpoint. We need to give the breakpoint a frame | |
656 | ID so that the breakpoint code can correctly re-identify the | |
657 | dummy breakpoint. */ | |
8241eaa6 | 658 | /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL, |
669fac23 | 659 | saved as the dummy-frame TOS, and used by dummy_id to form |
8241eaa6 | 660 | the frame ID's stack address. */ |
96860204 | 661 | dummy_id = frame_id_build (sp, bp_addr); |
04714b91 | 662 | |
74cfe982 AC |
663 | /* Create a momentary breakpoint at the return address of the |
664 | inferior. That way it breaks when it returns. */ | |
04714b91 | 665 | |
74cfe982 AC |
666 | { |
667 | struct breakpoint *bpt; | |
668 | struct symtab_and_line sal; | |
74cfe982 AC |
669 | init_sal (&sal); /* initialize to zeroes */ |
670 | sal.pc = bp_addr; | |
671 | sal.section = find_pc_overlay (sal.pc); | |
8241eaa6 AC |
672 | /* Sanity. The exact same SP value is returned by |
673 | PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by | |
669fac23 | 674 | dummy_id to form the frame ID's stack address. */ |
96860204 | 675 | bpt = set_momentary_breakpoint (sal, dummy_id, bp_call_dummy); |
74cfe982 AC |
676 | bpt->disposition = disp_del; |
677 | } | |
04714b91 | 678 | |
96860204 AC |
679 | /* Everything's ready, push all the info needed to restore the |
680 | caller (and identify the dummy-frame) onto the dummy-frame | |
681 | stack. */ | |
682 | dummy_frame_push (caller_regcache, &dummy_id); | |
683 | discard_cleanups (caller_regcache_cleanup); | |
684 | ||
685 | /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - | |
686 | If you're looking to implement asynchronous dummy-frames, then | |
687 | just below is the place to chop this function in two.. */ | |
688 | ||
689 | /* Now proceed, having reached the desired place. */ | |
690 | clear_proceed_status (); | |
691 | ||
74cfe982 AC |
692 | /* Execute a "stack dummy", a piece of code stored in the stack by |
693 | the debugger to be executed in the inferior. | |
04714b91 | 694 | |
74cfe982 AC |
695 | The dummy's frame is automatically popped whenever that break is |
696 | hit. If that is the first time the program stops, | |
697 | call_function_by_hand returns to its caller with that frame | |
698 | already gone and sets RC to 0. | |
699 | ||
700 | Otherwise, set RC to a non-zero value. If the called function | |
701 | receives a random signal, we do not allow the user to continue | |
702 | executing it as this may not work. The dummy frame is poped and | |
703 | we return 1. If we hit a breakpoint, we leave the frame in place | |
704 | and return 2 (the frame will eventually be popped when we do hit | |
705 | the dummy end breakpoint). */ | |
04714b91 | 706 | |
74cfe982 AC |
707 | { |
708 | struct cleanup *old_cleanups = make_cleanup (null_cleanup, 0); | |
f5871ec0 | 709 | struct cleanup *old_cleanups2; |
74cfe982 AC |
710 | int saved_async = 0; |
711 | ||
712 | /* If all error()s out of proceed ended up calling normal_stop | |
713 | (and perhaps they should; it already does in the special case | |
714 | of error out of resume()), then we wouldn't need this. */ | |
715 | make_cleanup (breakpoint_auto_delete_contents, &stop_bpstat); | |
716 | ||
717 | disable_watchpoints_before_interactive_call_start (); | |
718 | proceed_to_finish = 1; /* We want stop_registers, please... */ | |
719 | ||
720 | if (target_can_async_p ()) | |
721 | saved_async = target_async_mask (0); | |
f5871ec0 | 722 | |
8f6a8e84 VP |
723 | old_cleanups2 = make_cleanup_restore_integer (&suppress_resume_observer); |
724 | suppress_resume_observer = 1; | |
725 | make_cleanup_restore_integer (&suppress_stop_observer); | |
726 | suppress_stop_observer = 1; | |
74cfe982 | 727 | proceed (real_pc, TARGET_SIGNAL_0, 0); |
f5871ec0 | 728 | do_cleanups (old_cleanups2); |
74cfe982 AC |
729 | |
730 | if (saved_async) | |
731 | target_async_mask (saved_async); | |
732 | ||
733 | enable_watchpoints_after_interactive_call_stop (); | |
04714b91 | 734 | |
74cfe982 | 735 | discard_cleanups (old_cleanups); |
52557533 | 736 | } |
04714b91 | 737 | |
52557533 AC |
738 | if (stopped_by_random_signal || !stop_stack_dummy) |
739 | { | |
740 | /* Find the name of the function we're about to complain about. */ | |
edcf254d | 741 | const char *name = NULL; |
04714b91 | 742 | { |
52557533 AC |
743 | struct symbol *symbol = find_pc_function (funaddr); |
744 | if (symbol) | |
745 | name = SYMBOL_PRINT_NAME (symbol); | |
746 | else | |
04714b91 | 747 | { |
52557533 AC |
748 | /* Try the minimal symbols. */ |
749 | struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr); | |
750 | if (msymbol) | |
751 | name = SYMBOL_PRINT_NAME (msymbol); | |
752 | } | |
edcf254d AC |
753 | if (name == NULL) |
754 | { | |
755 | /* Can't use a cleanup here. It is discarded, instead use | |
756 | an alloca. */ | |
bb599908 | 757 | char *tmp = xstrprintf ("at %s", hex_string (funaddr)); |
edcf254d AC |
758 | char *a = alloca (strlen (tmp) + 1); |
759 | strcpy (a, tmp); | |
760 | xfree (tmp); | |
761 | name = a; | |
762 | } | |
52557533 | 763 | } |
52557533 AC |
764 | if (stopped_by_random_signal) |
765 | { | |
766 | /* We stopped inside the FUNCTION because of a random | |
767 | signal. Further execution of the FUNCTION is not | |
768 | allowed. */ | |
04714b91 | 769 | |
52557533 AC |
770 | if (unwind_on_signal_p) |
771 | { | |
772 | /* The user wants the context restored. */ | |
773 | ||
774 | /* We must get back to the frame we were before the | |
775 | dummy call. */ | |
776 | frame_pop (get_current_frame ()); | |
04714b91 | 777 | |
52557533 AC |
778 | /* FIXME: Insert a bunch of wrap_here; name can be very |
779 | long if it's a C++ name with arguments and stuff. */ | |
8a3fe4f8 | 780 | error (_("\ |
04714b91 AC |
781 | The program being debugged was signaled while in a function called from GDB.\n\ |
782 | GDB has restored the context to what it was before the call.\n\ | |
783 | To change this behavior use \"set unwindonsignal off\"\n\ | |
8a3fe4f8 | 784 | Evaluation of the expression containing the function (%s) will be abandoned."), |
52557533 AC |
785 | name); |
786 | } | |
787 | else | |
788 | { | |
789 | /* The user wants to stay in the frame where we stopped | |
790 | (default).*/ | |
791 | /* If we restored the inferior status (via the cleanup), | |
792 | we would print a spurious error message (Unable to | |
793 | restore previously selected frame), would write the | |
794 | registers from the inf_status (which is wrong), and | |
795 | would do other wrong things. */ | |
796 | discard_cleanups (inf_status_cleanup); | |
797 | discard_inferior_status (inf_status); | |
798 | /* FIXME: Insert a bunch of wrap_here; name can be very | |
799 | long if it's a C++ name with arguments and stuff. */ | |
8a3fe4f8 | 800 | error (_("\ |
04714b91 AC |
801 | The program being debugged was signaled while in a function called from GDB.\n\ |
802 | GDB remains in the frame where the signal was received.\n\ | |
803 | To change this behavior use \"set unwindonsignal on\"\n\ | |
8a3fe4f8 | 804 | Evaluation of the expression containing the function (%s) will be abandoned."), |
52557533 AC |
805 | name); |
806 | } | |
807 | } | |
04714b91 | 808 | |
52557533 AC |
809 | if (!stop_stack_dummy) |
810 | { | |
811 | /* We hit a breakpoint inside the FUNCTION. */ | |
812 | /* If we restored the inferior status (via the cleanup), we | |
813 | would print a spurious error message (Unable to restore | |
814 | previously selected frame), would write the registers | |
815 | from the inf_status (which is wrong), and would do other | |
816 | wrong things. */ | |
817 | discard_cleanups (inf_status_cleanup); | |
818 | discard_inferior_status (inf_status); | |
819 | /* The following error message used to say "The expression | |
820 | which contained the function call has been discarded." | |
821 | It is a hard concept to explain in a few words. Ideally, | |
822 | GDB would be able to resume evaluation of the expression | |
823 | when the function finally is done executing. Perhaps | |
824 | someday this will be implemented (it would not be easy). */ | |
825 | /* FIXME: Insert a bunch of wrap_here; name can be very long if it's | |
826 | a C++ name with arguments and stuff. */ | |
8a3fe4f8 | 827 | error (_("\ |
04714b91 AC |
828 | The program being debugged stopped while in a function called from GDB.\n\ |
829 | When the function (%s) is done executing, GDB will silently\n\ | |
830 | stop (instead of continuing to evaluate the expression containing\n\ | |
8a3fe4f8 | 831 | the function call)."), name); |
52557533 AC |
832 | } |
833 | ||
834 | /* The above code errors out, so ... */ | |
e2e0b3e5 | 835 | internal_error (__FILE__, __LINE__, _("... should not be here")); |
52557533 | 836 | } |
04714b91 | 837 | |
74cfe982 AC |
838 | /* If we get here the called FUNCTION run to completion. */ |
839 | ||
840 | /* On normal return, the stack dummy has been popped already. */ | |
841 | regcache_cpy_no_passthrough (retbuf, stop_registers); | |
842 | ||
843 | /* Restore the inferior status, via its cleanup. At this stage, | |
844 | leave the RETBUF alone. */ | |
845 | do_cleanups (inf_status_cleanup); | |
846 | ||
1a4d7a36 | 847 | /* Figure out the value returned by the function. */ |
44e5158b | 848 | { |
1a4d7a36 MK |
849 | struct value *retval = NULL; |
850 | ||
41f1b697 DJ |
851 | if (lang_struct_return) |
852 | retval = value_at (values_type, struct_addr); | |
853 | else if (TYPE_CODE (target_values_type) == TYPE_CODE_VOID) | |
44e5158b | 854 | { |
1a4d7a36 MK |
855 | /* If the function returns void, don't bother fetching the |
856 | return value. */ | |
df407dfe | 857 | retval = allocate_value (values_type); |
44e5158b | 858 | } |
1a4d7a36 MK |
859 | else |
860 | { | |
c055b101 CV |
861 | switch (gdbarch_return_value (gdbarch, value_type (function), |
862 | target_values_type, NULL, NULL, NULL)) | |
1a4d7a36 MK |
863 | { |
864 | case RETURN_VALUE_REGISTER_CONVENTION: | |
865 | case RETURN_VALUE_ABI_RETURNS_ADDRESS: | |
866 | case RETURN_VALUE_ABI_PRESERVES_ADDRESS: | |
867 | retval = allocate_value (values_type); | |
c055b101 CV |
868 | gdbarch_return_value (gdbarch, value_type (function), values_type, |
869 | retbuf, value_contents_raw (retval), NULL); | |
1a4d7a36 MK |
870 | break; |
871 | case RETURN_VALUE_STRUCT_CONVENTION: | |
872 | retval = value_at (values_type, struct_addr); | |
873 | break; | |
874 | } | |
875 | } | |
876 | ||
44e5158b | 877 | do_cleanups (retbuf_cleanup); |
1a4d7a36 MK |
878 | |
879 | gdb_assert(retval); | |
44e5158b AC |
880 | return retval; |
881 | } | |
04714b91 | 882 | } |
1a4d7a36 | 883 | \f |
04714b91 | 884 | |
1a4d7a36 | 885 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
04714b91 AC |
886 | void _initialize_infcall (void); |
887 | ||
888 | void | |
889 | _initialize_infcall (void) | |
890 | { | |
891 | add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure, | |
7915a72c AC |
892 | &coerce_float_to_double_p, _("\ |
893 | Set coercion of floats to doubles when calling functions."), _("\ | |
894 | Show coercion of floats to doubles when calling functions"), _("\ | |
04714b91 AC |
895 | Variables of type float should generally be converted to doubles before\n\ |
896 | calling an unprototyped function, and left alone when calling a prototyped\n\ | |
897 | function. However, some older debug info formats do not provide enough\n\ | |
898 | information to determine that a function is prototyped. If this flag is\n\ | |
899 | set, GDB will perform the conversion for a function it considers\n\ | |
900 | unprototyped.\n\ | |
7915a72c | 901 | The default is to perform the conversion.\n"), |
2c5b56ce | 902 | NULL, |
920d2a44 | 903 | show_coerce_float_to_double_p, |
2c5b56ce | 904 | &setlist, &showlist); |
04714b91 AC |
905 | |
906 | add_setshow_boolean_cmd ("unwindonsignal", no_class, | |
7915a72c AC |
907 | &unwind_on_signal_p, _("\ |
908 | Set unwinding of stack if a signal is received while in a call dummy."), _("\ | |
909 | Show unwinding of stack if a signal is received while in a call dummy."), _("\ | |
04714b91 AC |
910 | The unwindonsignal lets the user determine what gdb should do if a signal\n\ |
911 | is received while in a function called from gdb (call dummy). If set, gdb\n\ | |
912 | unwinds the stack and restore the context to what as it was before the call.\n\ | |
7915a72c | 913 | The default is to stop in the frame where the signal was received."), |
2c5b56ce | 914 | NULL, |
920d2a44 | 915 | show_unwind_on_signal_p, |
2c5b56ce | 916 | &setlist, &showlist); |
04714b91 | 917 | } |