Bug Summary

File:src/gnu/usr.bin/binutils/gdb/infcall.c
Warning:line 437, column 4
Value stored to 'dummy_addr' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name infcall.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/binutils/obj/gdb -resource-dir /usr/local/lib/clang/13.0.0 -D PIE_DEFAULT=1 -I . -I /usr/src/gnu/usr.bin/binutils/gdb -I /usr/src/gnu/usr.bin/binutils/gdb/config -D LOCALEDIR="/usr/share/locale" -D HAVE_CONFIG_H -I /usr/src/gnu/usr.bin/binutils/gdb/../include/opcode -I ../bfd -I /usr/src/gnu/usr.bin/binutils/gdb/../bfd -I /usr/src/gnu/usr.bin/binutils/gdb/../include -I ../intl -I /usr/src/gnu/usr.bin/binutils/gdb/../intl -D MI_OUT=1 -D TUI=1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/gnu/usr.bin/binutils/obj/gdb -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -fcommon -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/gnu/usr.bin/binutils/gdb/infcall.c
1/* Perform an inferior function call, for GDB, the GNU debugger.
2
3 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
4 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
5 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 2 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, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
23
24#include "defs.h"
25#include "breakpoint.h"
26#include "target.h"
27#include "regcache.h"
28#include "inferior.h"
29#include "gdb_assert.h"
30#include "block.h"
31#include "gdbcore.h"
32#include "language.h"
33#include "objfiles.h"
34#include "gdbcmd.h"
35#include "command.h"
36#include "gdb_string.h"
37#include "infcall.h"
38#include "dummy-frame.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
67static int coerce_float_to_double_p = 1;
68
69/* This boolean tells what gdb should do if a signal is received while
70 in a function called from gdb (call dummy). If set, gdb unwinds
71 the stack and restore the context to what as it was before the
72 call.
73
74 The default is to stop in the frame where the signal was received. */
75
76int unwind_on_signal_p = 0;
77
78/* Perform the standard coercions that are specified
79 for arguments to be passed to C functions.
80
81 If PARAM_TYPE is non-NULL, it is the expected parameter type.
82 IS_PROTOTYPED is non-zero if the function declaration is prototyped. */
83
84static struct value *
85value_arg_coerce (struct value *arg, struct type *param_type,
86 int is_prototyped)
87{
88 struct type *arg_type = check_typedef (VALUE_TYPE (arg)(arg)->type);
89 struct type *type
90 = param_type ? check_typedef (param_type) : arg_type;
91
92 switch (TYPE_CODE (type)(type)->main_type->code)
93 {
94 case TYPE_CODE_REF:
95 if (TYPE_CODE (arg_type)(arg_type)->main_type->code != TYPE_CODE_REF
96 && TYPE_CODE (arg_type)(arg_type)->main_type->code != TYPE_CODE_PTR)
97 {
98 arg = value_addr (arg);
99 VALUE_TYPE (arg)(arg)->type = param_type;
100 return arg;
101 }
102 break;
103 case TYPE_CODE_INT:
104 case TYPE_CODE_CHAR:
105 case TYPE_CODE_BOOL:
106 case TYPE_CODE_ENUM:
107 /* If we don't have a prototype, coerce to integer type if necessary. */
108 if (!is_prototyped)
109 {
110 if (TYPE_LENGTH (type)(type)->length < TYPE_LENGTH (builtin_type_int)(builtin_type_int)->length)
111 type = builtin_type_int;
112 }
113 /* Currently all target ABIs require at least the width of an integer
114 type for an argument. We may have to conditionalize the following
115 type coercion for future targets. */
116 if (TYPE_LENGTH (type)(type)->length < TYPE_LENGTH (builtin_type_int)(builtin_type_int)->length)
117 type = builtin_type_int;
118 break;
119 case TYPE_CODE_FLT:
120 if (!is_prototyped && coerce_float_to_double_p)
121 {
122 if (TYPE_LENGTH (type)(type)->length < TYPE_LENGTH (builtin_type_double)(builtin_type_double)->length)
123 type = builtin_type_double;
124 else if (TYPE_LENGTH (type)(type)->length > TYPE_LENGTH (builtin_type_double)(builtin_type_double)->length)
125 type = builtin_type_long_double;
126 }
127 break;
128 case TYPE_CODE_FUNC:
129 type = lookup_pointer_type (type);
130 break;
131 case TYPE_CODE_ARRAY:
132 /* Arrays are coerced to pointers to their first element, unless
133 they are vectors, in which case we want to leave them alone,
134 because they are passed by value. */
135 if (current_language->c_style_arrays)
136 if (!TYPE_VECTOR (type)((type)->main_type->flags & (1 << 12)))
137 type = lookup_pointer_type (TYPE_TARGET_TYPE (type)(type)->main_type->target_type);
138 break;
139 case TYPE_CODE_UNDEF:
140 case TYPE_CODE_PTR:
141 case TYPE_CODE_STRUCT:
142 case TYPE_CODE_UNION:
143 case TYPE_CODE_VOID:
144 case TYPE_CODE_SET:
145 case TYPE_CODE_RANGE:
146 case TYPE_CODE_STRING:
147 case TYPE_CODE_BITSTRING:
148 case TYPE_CODE_ERROR:
149 case TYPE_CODE_MEMBER:
150 case TYPE_CODE_METHOD:
151 case TYPE_CODE_COMPLEX:
152 default:
153 break;
154 }
155
156 return value_cast (type, arg);
157}
158
159/* Determine a function's address and its return type from its value.
160 Calls error() if the function is not valid for calling. */
161
162CORE_ADDR
163find_function_addr (struct value *function, struct type **retval_type)
164{
165 struct type *ftype = check_typedef (VALUE_TYPE (function)(function)->type);
166 enum type_code code = TYPE_CODE (ftype)(ftype)->main_type->code;
167 struct type *value_type;
168 CORE_ADDR funaddr;
169
170 /* If it's a member function, just look at the function
171 part of it. */
172
173 /* Determine address to call. */
174 if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
175 {
176 funaddr = VALUE_ADDRESS (function)(function)->location.address;
177 value_type = TYPE_TARGET_TYPE (ftype)(ftype)->main_type->target_type;
178 }
179 else if (code == TYPE_CODE_PTR)
180 {
181 funaddr = value_as_address (function);
182 ftype = check_typedef (TYPE_TARGET_TYPE (ftype)(ftype)->main_type->target_type);
183 if (TYPE_CODE (ftype)(ftype)->main_type->code == TYPE_CODE_FUNC
184 || TYPE_CODE (ftype)(ftype)->main_type->code == TYPE_CODE_METHOD)
185 {
186 funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
187 funaddr,
188 &current_target);
189 value_type = TYPE_TARGET_TYPE (ftype)(ftype)->main_type->target_type;
190 }
191 else
192 value_type = builtin_type_int;
193 }
194 else if (code == TYPE_CODE_INT)
195 {
196 /* Handle the case of functions lacking debugging info.
197 Their values are characters since their addresses are char */
198 if (TYPE_LENGTH (ftype)(ftype)->length == 1)
199 funaddr = value_as_address (value_addr (function));
200 else
201 /* Handle integer used as address of a function. */
202 funaddr = (CORE_ADDR) value_as_long (function);
203
204 value_type = builtin_type_int;
205 }
206 else
207 error ("Invalid data type for function to be called.");
208
209 if (retval_type != NULL((void*)0))
210 *retval_type = value_type;
211 return funaddr + DEPRECATED_FUNCTION_START_OFFSET(gdbarch_deprecated_function_start_offset (current_gdbarch));
212}
213
214/* Call breakpoint_auto_delete on the current contents of the bpstat
215 pointed to by arg (which is really a bpstat *). */
216
217static void
218breakpoint_auto_delete_contents (void *arg)
219{
220 breakpoint_auto_delete (*(bpstat *) arg);
221}
222
223static CORE_ADDR
224generic_push_dummy_code (struct gdbarch *gdbarch,
225 CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc,
226 struct value **args, int nargs,
227 struct type *value_type,
228 CORE_ADDR *real_pc, CORE_ADDR *bp_addr)
229{
230 /* Something here to findout the size of a breakpoint and then
231 allocate space for it on the stack. */
232 int bplen;
233 /* This code assumes frame align. */
234 gdb_assert (gdbarch_frame_align_p (gdbarch))((void) ((gdbarch_frame_align_p (gdbarch)) ? 0 : (internal_error
("/usr/src/gnu/usr.bin/binutils/gdb/infcall.c", 234, "%s: Assertion `%s' failed."
, __PRETTY_FUNCTION__, "gdbarch_frame_align_p (gdbarch)"), 0)
))
;
235 /* Force the stack's alignment. The intent is to ensure that the SP
236 is aligned to at least a breakpoint instruction's boundary. */
237 sp = gdbarch_frame_align (gdbarch, sp);
238 /* Allocate space for, and then position the breakpoint on the
239 stack. */
240 if (gdbarch_inner_than (gdbarch, 1, 2))
241 {
242 CORE_ADDR bppc = sp;
243 gdbarch_breakpoint_from_pc (gdbarch, &bppc, &bplen);
244 sp = gdbarch_frame_align (gdbarch, sp - bplen);
245 (*bp_addr) = sp;
246 /* Should the breakpoint size/location be re-computed here? */
247 }
248 else
249 {
250 (*bp_addr) = sp;
251 gdbarch_breakpoint_from_pc (gdbarch, bp_addr, &bplen);
252 sp = gdbarch_frame_align (gdbarch, sp + bplen);
253 }
254 /* Inferior resumes at the function entry point. */
255 (*real_pc) = funaddr;
256 return sp;
257}
258
259/* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
260 function returns to. */
261
262static CORE_ADDR
263push_dummy_code (struct gdbarch *gdbarch,
264 CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc,
265 struct value **args, int nargs,
266 struct type *value_type,
267 CORE_ADDR *real_pc, CORE_ADDR *bp_addr)
268{
269 if (gdbarch_push_dummy_code_p (gdbarch))
270 return gdbarch_push_dummy_code (gdbarch, sp, funaddr, using_gcc,
271 args, nargs, value_type, real_pc, bp_addr);
272 else
273 return generic_push_dummy_code (gdbarch, sp, funaddr, using_gcc,
274 args, nargs, value_type, real_pc, bp_addr);
275}
276
277/* All this stuff with a dummy frame may seem unnecessarily complicated
278 (why not just save registers in GDB?). The purpose of pushing a dummy
279 frame which looks just like a real frame is so that if you call a
280 function and then hit a breakpoint (get a signal, etc), "backtrace"
281 will look right. Whether the backtrace needs to actually show the
282 stack at the time the inferior function was called is debatable, but
283 it certainly needs to not display garbage. So if you are contemplating
284 making dummy frames be different from normal frames, consider that. */
285
286/* Perform a function call in the inferior.
287 ARGS is a vector of values of arguments (NARGS of them).
288 FUNCTION is a value, the function to be called.
289 Returns a value representing what the function returned.
290 May fail to return, if a breakpoint or signal is hit
291 during the execution of the function.
292
293 ARGS is modified to contain coerced values. */
294
295struct value *
296call_function_by_hand (struct value *function, int nargs, struct value **args)
297{
298 CORE_ADDR sp;
299 CORE_ADDR dummy_addr;
300 struct type *value_type;
301 unsigned char struct_return;
302 CORE_ADDR struct_addr = 0;
303 struct regcache *retbuf;
304 struct cleanup *retbuf_cleanup;
305 struct inferior_status *inf_status;
306 struct cleanup *inf_status_cleanup;
307 CORE_ADDR funaddr;
308 int using_gcc; /* Set to version of gcc in use, or zero if not gcc */
309 CORE_ADDR real_pc;
310 struct type *ftype = check_typedef (VALUE_TYPE (function)(function)->type);
311 CORE_ADDR bp_addr;
312 struct regcache *caller_regcache;
313 struct cleanup *caller_regcache_cleanup;
314 struct frame_id dummy_id;
315
316 if (!target_has_execution(current_target.to_has_execution))
317 noprocess ();
318
319 /* Create a cleanup chain that contains the retbuf (buffer
320 containing the register values). This chain is create BEFORE the
321 inf_status chain so that the inferior status can cleaned up
322 (restored or discarded) without having the retbuf freed. */
323 retbuf = regcache_xmalloc (current_gdbarch);
324 retbuf_cleanup = make_cleanup_regcache_xfree (retbuf);
325
326 /* A cleanup for the inferior status. Create this AFTER the retbuf
327 so that this can be discarded or applied without interfering with
328 the regbuf. */
329 inf_status = save_inferior_status (1);
330 inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status);
331
332 /* Save the caller's registers so that they can be restored once the
333 callee returns. To allow nested calls the registers are (further
334 down) pushed onto a dummy frame stack. Include a cleanup (which
335 is tossed once the regcache has been pushed). */
336 caller_regcache = frame_save_as_regcache (get_current_frame ());
337 caller_regcache_cleanup = make_cleanup_regcache_xfree (caller_regcache);
338
339 /* Ensure that the initial SP is correctly aligned. */
340 {
341 CORE_ADDR old_sp = read_sp ();
342 if (gdbarch_frame_align_p (current_gdbarch))
343 {
344 sp = gdbarch_frame_align (current_gdbarch, old_sp);
345 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
346 ABIs, a function can use memory beyond the inner most stack
347 address. AMD64 called that region the "red zone". Skip at
348 least the "red zone" size before allocating any space on
349 the stack. */
350 if (INNER_THAN (1, 2)(gdbarch_inner_than (current_gdbarch, 1, 2)))
351 sp -= gdbarch_frame_red_zone_size (current_gdbarch);
352 else
353 sp += gdbarch_frame_red_zone_size (current_gdbarch);
354 /* Still aligned? */
355 gdb_assert (sp == gdbarch_frame_align (current_gdbarch, sp))((void) ((sp == gdbarch_frame_align (current_gdbarch, sp)) ? 0
: (internal_error ("/usr/src/gnu/usr.bin/binutils/gdb/infcall.c"
, 355, "%s: Assertion `%s' failed.", __PRETTY_FUNCTION__, "sp == gdbarch_frame_align (current_gdbarch, sp)"
), 0)))
;
356 /* NOTE: cagney/2002-09-18:
357
358 On a RISC architecture, a void parameterless generic dummy
359 frame (i.e., no parameters, no result) typically does not
360 need to push anything the stack and hence can leave SP and
361 FP. Similarly, a frameless (possibly leaf) function does
362 not push anything on the stack and, hence, that too can
363 leave FP and SP unchanged. As a consequence, a sequence of
364 void parameterless generic dummy frame calls to frameless
365 functions will create a sequence of effectively identical
366 frames (SP, FP and TOS and PC the same). This, not
367 suprisingly, results in what appears to be a stack in an
368 infinite loop --- when GDB tries to find a generic dummy
369 frame on the internal dummy frame stack, it will always
370 find the first one.
371
372 To avoid this problem, the code below always grows the
373 stack. That way, two dummy frames can never be identical.
374 It does burn a few bytes of stack but that is a small price
375 to pay :-). */
376 if (sp == old_sp)
377 {
378 if (INNER_THAN (1, 2)(gdbarch_inner_than (current_gdbarch, 1, 2)))
379 /* Stack grows down. */
380 sp = gdbarch_frame_align (current_gdbarch, old_sp - 1);
381 else
382 /* Stack grows up. */
383 sp = gdbarch_frame_align (current_gdbarch, old_sp + 1);
384 }
385 gdb_assert ((INNER_THAN (1, 2) && sp <= old_sp)((void) ((((gdbarch_inner_than (current_gdbarch, 1, 2)) &&
sp <= old_sp) || ((gdbarch_inner_than (current_gdbarch, 2
, 1)) && sp >= old_sp)) ? 0 : (internal_error ("/usr/src/gnu/usr.bin/binutils/gdb/infcall.c"
, 386, "%s: Assertion `%s' failed.", __PRETTY_FUNCTION__, "(INNER_THAN (1, 2) && sp <= old_sp) || (INNER_THAN (2, 1) && sp >= old_sp)"
), 0)))
386 || (INNER_THAN (2, 1) && sp >= old_sp))((void) ((((gdbarch_inner_than (current_gdbarch, 1, 2)) &&
sp <= old_sp) || ((gdbarch_inner_than (current_gdbarch, 2
, 1)) && sp >= old_sp)) ? 0 : (internal_error ("/usr/src/gnu/usr.bin/binutils/gdb/infcall.c"
, 386, "%s: Assertion `%s' failed.", __PRETTY_FUNCTION__, "(INNER_THAN (1, 2) && sp <= old_sp) || (INNER_THAN (2, 1) && sp >= old_sp)"
), 0)))
;
387 }
388 else
389 /* FIXME: cagney/2002-09-18: Hey, you loose!
390
391 Who knows how badly aligned the SP is!
392
393 If the generic dummy frame ends up empty (because nothing is
394 pushed) GDB won't be able to correctly perform back traces.
395 If a target is having trouble with backtraces, first thing to
396 do is add FRAME_ALIGN() to the architecture vector. If that
397 fails, try unwind_dummy_id().
398
399 If the ABI specifies a "Red Zone" (see the doco) the code
400 below will quietly trash it. */
401 sp = old_sp;
402 }
403
404 funaddr = find_function_addr (function, &value_type);
405 CHECK_TYPEDEF (value_type)(value_type) = check_typedef (value_type);
406
407 {
408 struct block *b = block_for_pc (funaddr);
409 /* If compiled without -g, assume GCC 2. */
410 using_gcc = (b == NULL((void*)0) ? 2 : BLOCK_GCC_COMPILED (b)(b)->gcc_compile_flag);
411 }
412
413 /* Are we returning a value using a structure return or a normal
414 value return? */
415
416 struct_return = using_struct_return (value_type, using_gcc);
417
418 /* Determine the location of the breakpoint (and possibly other
419 stuff) that the called function will return to. The SPARC, for a
420 function returning a structure or union, needs to make space for
421 not just the breakpoint but also an extra word containing the
422 size (?) of the structure being passed. */
423
424 /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
425 is no need to write that out. */
426
427 switch (CALL_DUMMY_LOCATION(gdbarch_call_dummy_location (current_gdbarch)))
428 {
429 case ON_STACK1:
430 /* "dummy_addr" is here just to keep old targets happy. New
431 targets return that same information via "sp" and "bp_addr". */
432 if (INNER_THAN (1, 2)(gdbarch_inner_than (current_gdbarch, 1, 2)))
433 {
434 sp = push_dummy_code (current_gdbarch, sp, funaddr,
435 using_gcc, args, nargs, value_type,
436 &real_pc, &bp_addr);
437 dummy_addr = sp;
Value stored to 'dummy_addr' is never read
438 }
439 else
440 {
441 dummy_addr = sp;
442 sp = push_dummy_code (current_gdbarch, sp, funaddr,
443 using_gcc, args, nargs, value_type,
444 &real_pc, &bp_addr);
445 }
446 break;
447 case AT_ENTRY_POINT4:
448 real_pc = funaddr;
449 dummy_addr = entry_point_address ();
450 /* Make certain that the address points at real code, and not a
451 function descriptor. */
452 dummy_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
453 dummy_addr,
454 &current_target);
455 /* A call dummy always consists of just a single breakpoint, so
456 it's address is the same as the address of the dummy. */
457 bp_addr = dummy_addr;
458 break;
459 case AT_SYMBOL5:
460 /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
461 address is the location where the breakpoint should be
462 placed. Once all targets are using the overhauled frame code
463 this can be deleted - ON_STACK is a better option. */
464 {
465 struct minimal_symbol *sym;
466
467 sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL((void*)0), NULL((void*)0));
468 real_pc = funaddr;
469 if (sym)
470 dummy_addr = SYMBOL_VALUE_ADDRESS (sym)(sym)->ginfo.value.address;
471 else
472 dummy_addr = entry_point_address ();
473 /* Make certain that the address points at real code, and not
474 a function descriptor. */
475 dummy_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
476 dummy_addr,
477 &current_target);
478 /* A call dummy always consists of just a single breakpoint,
479 so it's address is the same as the address of the dummy. */
480 bp_addr = dummy_addr;
481 break;
482 }
483 default:
484 internal_error (__FILE__"/usr/src/gnu/usr.bin/binutils/gdb/infcall.c", __LINE__484, "bad switch");
485 }
486
487 if (nargs < TYPE_NFIELDS (ftype)(ftype)->main_type->nfields)
488 error ("too few arguments in function call");
489
490 {
491 int i;
492 for (i = nargs - 1; i >= 0; i--)
493 {
494 int prototyped;
495 struct type *param_type;
496
497 /* FIXME drow/2002-05-31: Should just always mark methods as
498 prototyped. Can we respect TYPE_VARARGS? Probably not. */
499 if (TYPE_CODE (ftype)(ftype)->main_type->code == TYPE_CODE_METHOD)
500 prototyped = 1;
501 else if (i < TYPE_NFIELDS (ftype)(ftype)->main_type->nfields)
502 prototyped = TYPE_PROTOTYPED (ftype)((ftype)->main_type->flags & (1 << 7));
503 else
504 prototyped = 0;
505
506 if (i < TYPE_NFIELDS (ftype)(ftype)->main_type->nfields)
507 param_type = TYPE_FIELD_TYPE (ftype, i)(((ftype)->main_type->fields[i]).type);
508 else
509 param_type = NULL((void*)0);
510
511 args[i] = value_arg_coerce (args[i], param_type, prototyped);
512
513 /* elz: this code is to handle the case in which the function
514 to be called has a pointer to function as parameter and the
515 corresponding actual argument is the address of a function
516 and not a pointer to function variable. In aCC compiled
517 code, the calls through pointers to functions (in the body
518 of the function called by hand) are made via
519 $$dyncall_external which requires some registers setting,
520 this is taken care of if we call via a function pointer
521 variable, but not via a function address. In cc this is
522 not a problem. */
523
524 if (using_gcc == 0)
525 {
526 if (param_type != NULL((void*)0) && TYPE_CODE (ftype)(ftype)->main_type->code != TYPE_CODE_METHOD)
527 {
528 /* if this parameter is a pointer to function. */
529 if (TYPE_CODE (param_type)(param_type)->main_type->code == TYPE_CODE_PTR)
530 if (TYPE_CODE (TYPE_TARGET_TYPE (param_type))((param_type)->main_type->target_type)->main_type->
code
== TYPE_CODE_FUNC)
531 /* elz: FIXME here should go the test about the
532 compiler used to compile the target. We want to
533 issue the error message only if the compiler
534 used was HP's aCC. If we used HP's cc, then
535 there is no problem and no need to return at
536 this point. */
537 /* Go see if the actual parameter is a variable of
538 type pointer to function or just a function. */
539 if (args[i]->lval == not_lval)
540 {
541 char *arg_name;
542 if (find_pc_partial_function ((CORE_ADDR) args[i]->aligner.contents[0], &arg_name, NULL((void*)0), NULL((void*)0)))
543 error ("\
544You cannot use function <%s> as argument. \n\
545You must use a pointer to function type variable. Command ignored.", arg_name);
546 }
547 }
548 }
549 }
550 }
551
552 if (DEPRECATED_REG_STRUCT_HAS_ADDR_P ()(gdbarch_deprecated_reg_struct_has_addr_p (current_gdbarch)))
553 {
554 int i;
555 /* This is a machine like the sparc, where we may need to pass a
556 pointer to the structure, not the structure itself. */
557 for (i = nargs - 1; i >= 0; i--)
558 {
559 struct type *arg_type = check_typedef (VALUE_TYPE (args[i])(args[i])->type);
560 if ((TYPE_CODE (arg_type)(arg_type)->main_type->code == TYPE_CODE_STRUCT
561 || TYPE_CODE (arg_type)(arg_type)->main_type->code == TYPE_CODE_UNION
562 || TYPE_CODE (arg_type)(arg_type)->main_type->code == TYPE_CODE_ARRAY
563 || TYPE_CODE (arg_type)(arg_type)->main_type->code == TYPE_CODE_STRING
564 || TYPE_CODE (arg_type)(arg_type)->main_type->code == TYPE_CODE_BITSTRING
565 || TYPE_CODE (arg_type)(arg_type)->main_type->code == TYPE_CODE_SET
566 || (TYPE_CODE (arg_type)(arg_type)->main_type->code == TYPE_CODE_FLT
567 && TYPE_LENGTH (arg_type)(arg_type)->length > 8)
568 )
569 && DEPRECATED_REG_STRUCT_HAS_ADDR (using_gcc, arg_type)(gdbarch_deprecated_reg_struct_has_addr (current_gdbarch, using_gcc
, arg_type))
)
570 {
571 CORE_ADDR addr;
572 int len; /* = TYPE_LENGTH (arg_type); */
573 int aligned_len;
574 arg_type = check_typedef (VALUE_ENCLOSING_TYPE (args[i])(args[i])->enclosing_type);
575 len = TYPE_LENGTH (arg_type)(arg_type)->length;
576
577 aligned_len = len;
578 if (INNER_THAN (1, 2)(gdbarch_inner_than (current_gdbarch, 1, 2)))
579 {
580 /* stack grows downward */
581 sp -= aligned_len;
582 /* ... so the address of the thing we push is the
583 stack pointer after we push it. */
584 addr = sp;
585 }
586 else
587 {
588 /* The stack grows up, so the address of the thing
589 we push is the stack pointer before we push it. */
590 addr = sp;
591 sp += aligned_len;
592 }
593 /* Push the structure. */
594 write_memory (addr, VALUE_CONTENTS_ALL (args[i])((void) ((args[i])->lazy && value_fetch_lazy(args[
i])), ((char *) (args[i])->aligner.contents))
, len);
595 /* The value we're going to pass is the address of the
596 thing we just pushed. */
597 /*args[i] = value_from_longest (lookup_pointer_type (value_type),
598 (LONGEST) addr); */
599 args[i] = value_from_pointer (lookup_pointer_type (arg_type),
600 addr);
601 }
602 }
603 }
604
605
606 /* Reserve space for the return structure to be written on the
607 stack, if necessary. Make certain that the value is correctly
608 aligned. */
609
610 if (struct_return)
611 {
612 int len = TYPE_LENGTH (value_type)(value_type)->length;
613 if (INNER_THAN (1, 2)(gdbarch_inner_than (current_gdbarch, 1, 2)))
614 {
615 /* Stack grows downward. Align STRUCT_ADDR and SP after
616 making space for the return value. */
617 sp -= len;
618 if (gdbarch_frame_align_p (current_gdbarch))
619 sp = gdbarch_frame_align (current_gdbarch, sp);
620 struct_addr = sp;
621 }
622 else
623 {
624 /* Stack grows upward. Align the frame, allocate space, and
625 then again, re-align the frame??? */
626 if (gdbarch_frame_align_p (current_gdbarch))
627 sp = gdbarch_frame_align (current_gdbarch, sp);
628 struct_addr = sp;
629 sp += len;
630 if (gdbarch_frame_align_p (current_gdbarch))
631 sp = gdbarch_frame_align (current_gdbarch, sp);
632 }
633 }
634
635 /* Create the dummy stack frame. Pass in the call dummy address as,
636 presumably, the ABI code knows where, in the call dummy, the
637 return address should be pointed. */
638 if (gdbarch_push_dummy_call_p (current_gdbarch))
639 /* When there is no push_dummy_call method, should this code
640 simply error out. That would the implementation of this method
641 for all ABIs (which is probably a good thing). */
642 sp = gdbarch_push_dummy_call (current_gdbarch, function, current_regcache,
643 bp_addr, nargs, args, sp, struct_return,
644 struct_addr);
645 else if (DEPRECATED_PUSH_ARGUMENTS_P ()(gdbarch_deprecated_push_arguments_p (current_gdbarch)))
646 /* Keep old targets working. */
647 sp = DEPRECATED_PUSH_ARGUMENTS (nargs, args, sp, struct_return,(gdbarch_deprecated_push_arguments (current_gdbarch, nargs, args
, sp, struct_return, struct_addr))
648 struct_addr)(gdbarch_deprecated_push_arguments (current_gdbarch, nargs, args
, sp, struct_return, struct_addr))
;
649 else
650 error ("This target does not support function calls");
651
652 /* Set up a frame ID for the dummy frame so we can pass it to
653 set_momentary_breakpoint. We need to give the breakpoint a frame
654 ID so that the breakpoint code can correctly re-identify the
655 dummy breakpoint. */
656 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
657 saved as the dummy-frame TOS, and used by unwind_dummy_id to form
658 the frame ID's stack address. */
659 dummy_id = frame_id_build (sp, bp_addr);
660
661 /* Create a momentary breakpoint at the return address of the
662 inferior. That way it breaks when it returns. */
663
664 {
665 struct breakpoint *bpt;
666 struct symtab_and_line sal;
667 init_sal (&sal); /* initialize to zeroes */
668 sal.pc = bp_addr;
669 sal.section = find_pc_overlay (sal.pc);
670 /* Sanity. The exact same SP value is returned by
671 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
672 unwind_dummy_id to form the frame ID's stack address. */
673 bpt = set_momentary_breakpoint (sal, dummy_id, bp_call_dummy);
674 bpt->disposition = disp_del;
675 }
676
677 /* Everything's ready, push all the info needed to restore the
678 caller (and identify the dummy-frame) onto the dummy-frame
679 stack. */
680 dummy_frame_push (caller_regcache, &dummy_id);
681 discard_cleanups (caller_regcache_cleanup);
682
683 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
684 If you're looking to implement asynchronous dummy-frames, then
685 just below is the place to chop this function in two.. */
686
687 /* Now proceed, having reached the desired place. */
688 clear_proceed_status ();
689
690 /* Execute a "stack dummy", a piece of code stored in the stack by
691 the debugger to be executed in the inferior.
692
693 The dummy's frame is automatically popped whenever that break is
694 hit. If that is the first time the program stops,
695 call_function_by_hand returns to its caller with that frame
696 already gone and sets RC to 0.
697
698 Otherwise, set RC to a non-zero value. If the called function
699 receives a random signal, we do not allow the user to continue
700 executing it as this may not work. The dummy frame is poped and
701 we return 1. If we hit a breakpoint, we leave the frame in place
702 and return 2 (the frame will eventually be popped when we do hit
703 the dummy end breakpoint). */
704
705 {
706 struct cleanup *old_cleanups = make_cleanup (null_cleanup, 0);
707 int saved_async = 0;
708
709 /* If all error()s out of proceed ended up calling normal_stop
710 (and perhaps they should; it already does in the special case
711 of error out of resume()), then we wouldn't need this. */
712 make_cleanup (breakpoint_auto_delete_contents, &stop_bpstat);
713
714 disable_watchpoints_before_interactive_call_start ();
715 proceed_to_finish = 1; /* We want stop_registers, please... */
716
717 if (target_can_async_p ()(current_target.to_can_async_p ()))
718 saved_async = target_async_mask (0);
719
720 proceed (real_pc, TARGET_SIGNAL_0, 0);
721
722 if (saved_async)
723 target_async_mask (saved_async);
724
725 enable_watchpoints_after_interactive_call_stop ();
726
727 discard_cleanups (old_cleanups);
728 }
729
730 if (stopped_by_random_signal || !stop_stack_dummy)
731 {
732 /* Find the name of the function we're about to complain about. */
733 const char *name = NULL((void*)0);
734 {
735 struct symbol *symbol = find_pc_function (funaddr);
736 if (symbol)
737 name = SYMBOL_PRINT_NAME (symbol)(demangle ? (symbol_natural_name (&(symbol)->ginfo)) :
(symbol)->ginfo.name)
;
738 else
739 {
740 /* Try the minimal symbols. */
741 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
742 if (msymbol)
743 name = SYMBOL_PRINT_NAME (msymbol)(demangle ? (symbol_natural_name (&(msymbol)->ginfo)) :
(msymbol)->ginfo.name)
;
744 }
745 if (name == NULL((void*)0))
746 {
747 /* Can't use a cleanup here. It is discarded, instead use
748 an alloca. */
749 char *tmp = xstrprintf ("at %s", hex_string (funaddr));
750 char *a = alloca (strlen (tmp) + 1)__builtin_alloca(strlen (tmp) + 1);
751 strcpy (a, tmp);
752 xfree (tmp);
753 name = a;
754 }
755 }
756 if (stopped_by_random_signal)
757 {
758 /* We stopped inside the FUNCTION because of a random
759 signal. Further execution of the FUNCTION is not
760 allowed. */
761
762 if (unwind_on_signal_p)
763 {
764 /* The user wants the context restored. */
765
766 /* We must get back to the frame we were before the
767 dummy call. */
768 frame_pop (get_current_frame ());
769
770 /* FIXME: Insert a bunch of wrap_here; name can be very
771 long if it's a C++ name with arguments and stuff. */
772 error ("\
773The program being debugged was signaled while in a function called from GDB.\n\
774GDB has restored the context to what it was before the call.\n\
775To change this behavior use \"set unwindonsignal off\"\n\
776Evaluation of the expression containing the function (%s) will be abandoned.",
777 name);
778 }
779 else
780 {
781 /* The user wants to stay in the frame where we stopped
782 (default).*/
783 /* If we restored the inferior status (via the cleanup),
784 we would print a spurious error message (Unable to
785 restore previously selected frame), would write the
786 registers from the inf_status (which is wrong), and
787 would do other wrong things. */
788 discard_cleanups (inf_status_cleanup);
789 discard_inferior_status (inf_status);
790 /* FIXME: Insert a bunch of wrap_here; name can be very
791 long if it's a C++ name with arguments and stuff. */
792 error ("\
793The program being debugged was signaled while in a function called from GDB.\n\
794GDB remains in the frame where the signal was received.\n\
795To change this behavior use \"set unwindonsignal on\"\n\
796Evaluation of the expression containing the function (%s) will be abandoned.",
797 name);
798 }
799 }
800
801 if (!stop_stack_dummy)
802 {
803 /* We hit a breakpoint inside the FUNCTION. */
804 /* If we restored the inferior status (via the cleanup), we
805 would print a spurious error message (Unable to restore
806 previously selected frame), would write the registers
807 from the inf_status (which is wrong), and would do other
808 wrong things. */
809 discard_cleanups (inf_status_cleanup);
810 discard_inferior_status (inf_status);
811 /* The following error message used to say "The expression
812 which contained the function call has been discarded."
813 It is a hard concept to explain in a few words. Ideally,
814 GDB would be able to resume evaluation of the expression
815 when the function finally is done executing. Perhaps
816 someday this will be implemented (it would not be easy). */
817 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
818 a C++ name with arguments and stuff. */
819 error ("\
820The program being debugged stopped while in a function called from GDB.\n\
821When the function (%s) is done executing, GDB will silently\n\
822stop (instead of continuing to evaluate the expression containing\n\
823the function call).", name);
824 }
825
826 /* The above code errors out, so ... */
827 internal_error (__FILE__"/usr/src/gnu/usr.bin/binutils/gdb/infcall.c", __LINE__827, "... should not be here");
828 }
829
830 /* If we get here the called FUNCTION run to completion. */
831
832 /* On normal return, the stack dummy has been popped already. */
833 regcache_cpy_no_passthrough (retbuf, stop_registers);
834
835 /* Restore the inferior status, via its cleanup. At this stage,
836 leave the RETBUF alone. */
837 do_cleanups (inf_status_cleanup);
838
839 /* Figure out the value returned by the function, return that. */
840 {
841 struct value *retval;
842 if (TYPE_CODE (value_type)(value_type)->main_type->code == TYPE_CODE_VOID)
843 /* If the function returns void, don't bother fetching the
844 return value. */
845 retval = allocate_value (value_type);
846 else if (struct_return)
847 /* NOTE: cagney/2003-09-27: This assumes that PUSH_DUMMY_CALL
848 has correctly stored STRUCT_ADDR in the target. In the past
849 that hasn't been the case, the old MIPS PUSH_ARGUMENTS
850 (PUSH_DUMMY_CALL precursor) would silently move the location
851 of the struct return value making STRUCT_ADDR bogus. If
852 you're seeing problems with values being returned using the
853 "struct return convention", check that PUSH_DUMMY_CALL isn't
854 playing tricks. */
855 retval = value_at (value_type, struct_addr, NULL((void*)0));
856 else
857 {
858 /* This code only handles "register convention". */
859 retval = allocate_value (value_type);
860 gdb_assert (gdbarch_return_value (current_gdbarch, value_type,((void) ((gdbarch_return_value (current_gdbarch, value_type, (
(void*)0), ((void*)0), ((void*)0)) == RETURN_VALUE_REGISTER_CONVENTION
) ? 0 : (internal_error ("/usr/src/gnu/usr.bin/binutils/gdb/infcall.c"
, 862, "%s: Assertion `%s' failed.", __PRETTY_FUNCTION__, "gdbarch_return_value (current_gdbarch, value_type, NULL, NULL, NULL) == RETURN_VALUE_REGISTER_CONVENTION"
), 0)))
861 NULL, NULL, NULL)((void) ((gdbarch_return_value (current_gdbarch, value_type, (
(void*)0), ((void*)0), ((void*)0)) == RETURN_VALUE_REGISTER_CONVENTION
) ? 0 : (internal_error ("/usr/src/gnu/usr.bin/binutils/gdb/infcall.c"
, 862, "%s: Assertion `%s' failed.", __PRETTY_FUNCTION__, "gdbarch_return_value (current_gdbarch, value_type, NULL, NULL, NULL) == RETURN_VALUE_REGISTER_CONVENTION"
), 0)))
862 == RETURN_VALUE_REGISTER_CONVENTION)((void) ((gdbarch_return_value (current_gdbarch, value_type, (
(void*)0), ((void*)0), ((void*)0)) == RETURN_VALUE_REGISTER_CONVENTION
) ? 0 : (internal_error ("/usr/src/gnu/usr.bin/binutils/gdb/infcall.c"
, 862, "%s: Assertion `%s' failed.", __PRETTY_FUNCTION__, "gdbarch_return_value (current_gdbarch, value_type, NULL, NULL, NULL) == RETURN_VALUE_REGISTER_CONVENTION"
), 0)))
;
863 gdbarch_return_value (current_gdbarch, value_type, retbuf,
864 VALUE_CONTENTS_RAW (retval)((char *) (retval)->aligner.contents + (retval)->embedded_offset
)
/*read*/,
865 NULL((void*)0) /*write*/);
866 }
867 do_cleanups (retbuf_cleanup);
868 return retval;
869 }
870}
871
872void _initialize_infcall (void);
873
874void
875_initialize_infcall (void)
876{
877 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure,
878 &coerce_float_to_double_p, "\
879Set coercion of floats to doubles when calling functions.", "\
880Show coercion of floats to doubles when calling functions", "\
881Variables of type float should generally be converted to doubles before\n\
882calling an unprototyped function, and left alone when calling a prototyped\n\
883function. However, some older debug info formats do not provide enough\n\
884information to determine that a function is prototyped. If this flag is\n\
885set, GDB will perform the conversion for a function it considers\n\
886unprototyped.\n\
887The default is to perform the conversion.\n", "\
888Coercion of floats to doubles when calling functions is %s.",
889 NULL((void*)0), NULL((void*)0), &setlist, &showlist);
890
891 add_setshow_boolean_cmd ("unwindonsignal", no_class,
892 &unwind_on_signal_p, "\
893Set unwinding of stack if a signal is received while in a call dummy.", "\
894Show unwinding of stack if a signal is received while in a call dummy.", "\
895The unwindonsignal lets the user determine what gdb should do if a signal\n\
896is received while in a function called from gdb (call dummy). If set, gdb\n\
897unwinds the stack and restore the context to what as it was before the call.\n\
898The default is to stop in the frame where the signal was received.", "\
899Unwinding of stack if a signal is received while in a call dummy is %s.",
900 NULL((void*)0), NULL((void*)0), &setlist, &showlist);
901}