xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/probe.c (revision 8b657b0747480f8989760d71343d6dd33f8d4cf9)
1 /* Generic static probe support for GDB.
2 
3    Copyright (C) 2012-2023 Free Software Foundation, Inc.
4 
5    This file is part of GDB.
6 
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 3 of the License, or
10    (at your option) any later version.
11 
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19 
20 #include "defs.h"
21 #include "probe.h"
22 #include "command.h"
23 #include "cli/cli-cmds.h"
24 #include "cli/cli-utils.h"
25 #include "objfiles.h"
26 #include "symtab.h"
27 #include "progspace.h"
28 #include "filenames.h"
29 #include "linespec.h"
30 #include "gdbsupport/gdb_regex.h"
31 #include "frame.h"
32 #include "arch-utils.h"
33 #include "value.h"
34 #include "ax.h"
35 #include "ax-gdb.h"
36 #include "location.h"
37 #include <ctype.h>
38 #include <algorithm>
39 #include "gdbsupport/gdb_optional.h"
40 
41 /* Class that implements the static probe methods for "any" probe.  */
42 
43 class any_static_probe_ops : public static_probe_ops
44 {
45 public:
46   /* See probe.h.  */
47   bool is_linespec (const char **linespecp) const override;
48 
49   /* See probe.h.  */
50   void get_probes (std::vector<std::unique_ptr<probe>> *probesp,
51 		   struct objfile *objfile) const override;
52 
53   /* See probe.h.  */
54   const char *type_name () const override;
55 
56   /* See probe.h.  */
57   std::vector<struct info_probe_column> gen_info_probes_table_header
58     () const override;
59 };
60 
61 /* Static operations associated with a generic probe.  */
62 
63 const any_static_probe_ops any_static_probe_ops {};
64 
65 /* A helper for parse_probes that decodes a probe specification in
66    SEARCH_PSPACE.  It appends matching SALs to RESULT.  */
67 
68 static void
69 parse_probes_in_pspace (const static_probe_ops *spops,
70 			struct program_space *search_pspace,
71 			const char *objfile_namestr,
72 			const char *provider,
73 			const char *name,
74 			std::vector<symtab_and_line> *result)
75 {
76   for (objfile *objfile : search_pspace->objfiles ())
77     {
78       if (!objfile->sf || !objfile->sf->sym_probe_fns)
79 	continue;
80 
81       if (objfile_namestr
82 	  && FILENAME_CMP (objfile_name (objfile), objfile_namestr) != 0
83 	  && FILENAME_CMP (lbasename (objfile_name (objfile)),
84 			   objfile_namestr) != 0)
85 	continue;
86 
87       const std::vector<std::unique_ptr<probe>> &probes
88 	= objfile->sf->sym_probe_fns->sym_get_probes (objfile);
89 
90       for (auto &p : probes)
91 	{
92 	  if (spops != &any_static_probe_ops && p->get_static_ops () != spops)
93 	    continue;
94 
95 	  if (provider != NULL && p->get_provider () != provider)
96 	    continue;
97 
98 	  if (p->get_name () != name)
99 	    continue;
100 
101 	  symtab_and_line sal;
102 	  sal.pc = p->get_relocated_address (objfile);
103 	  sal.explicit_pc = 1;
104 	  sal.section = find_pc_overlay (sal.pc);
105 	  sal.pspace = search_pspace;
106 	  sal.prob = p.get ();
107 	  sal.objfile = objfile;
108 
109 	  result->push_back (std::move (sal));
110 	}
111     }
112 }
113 
114 /* See definition in probe.h.  */
115 
116 std::vector<symtab_and_line>
117 parse_probes (const location_spec *locspec,
118 	      struct program_space *search_pspace,
119 	      struct linespec_result *canonical)
120 {
121   char *arg_end, *arg;
122   char *objfile_namestr = NULL, *provider = NULL, *name, *p;
123   const char *arg_start, *cs;
124 
125   gdb_assert (locspec->type () == PROBE_LOCATION_SPEC);
126   arg_start = locspec->to_string ();
127 
128   cs = arg_start;
129   const static_probe_ops *spops = probe_linespec_to_static_ops (&cs);
130   if (spops == NULL)
131     error (_("'%s' is not a probe linespec"), arg_start);
132 
133   arg = (char *) cs;
134   arg = skip_spaces (arg);
135   if (!*arg)
136     error (_("argument to `%s' missing"), arg_start);
137 
138   arg_end = skip_to_space (arg);
139 
140   /* We make a copy here so we can write over parts with impunity.  */
141   std::string copy (arg, arg_end - arg);
142   arg = &copy[0];
143 
144   /* Extract each word from the argument, separated by ":"s.  */
145   p = strchr (arg, ':');
146   if (p == NULL)
147     {
148       /* This is `-p name'.  */
149       name = arg;
150     }
151   else
152     {
153       char *hold = p + 1;
154 
155       *p = '\0';
156       p = strchr (hold, ':');
157       if (p == NULL)
158 	{
159 	  /* This is `-p provider:name'.  */
160 	  provider = arg;
161 	  name = hold;
162 	}
163       else
164 	{
165 	  /* This is `-p objfile:provider:name'.  */
166 	  *p = '\0';
167 	  objfile_namestr = arg;
168 	  provider = hold;
169 	  name = p + 1;
170 	}
171     }
172 
173   if (*name == '\0')
174     error (_("no probe name specified"));
175   if (provider && *provider == '\0')
176     error (_("invalid provider name"));
177   if (objfile_namestr && *objfile_namestr == '\0')
178     error (_("invalid objfile name"));
179 
180   std::vector<symtab_and_line> result;
181   if (search_pspace != NULL)
182     {
183       parse_probes_in_pspace (spops, search_pspace, objfile_namestr,
184 			      provider, name, &result);
185     }
186   else
187     {
188       for (struct program_space *pspace : program_spaces)
189 	parse_probes_in_pspace (spops, pspace, objfile_namestr,
190 				provider, name, &result);
191     }
192 
193   if (result.empty ())
194     {
195       throw_error (NOT_FOUND_ERROR,
196 		   _("No probe matching objfile=`%s', provider=`%s', name=`%s'"),
197 		   objfile_namestr ? objfile_namestr : _("<any>"),
198 		   provider ? provider : _("<any>"),
199 		   name);
200     }
201 
202   if (canonical)
203     {
204       std::string canon (arg_start, arg_end - arg_start);
205       canonical->special_display = 1;
206       canonical->pre_expanded = 1;
207       canonical->locspec = new_probe_location_spec (std::move (canon));
208     }
209 
210   return result;
211 }
212 
213 /* See definition in probe.h.  */
214 
215 std::vector<probe *>
216 find_probes_in_objfile (struct objfile *objfile, const char *provider,
217 			const char *name)
218 {
219   std::vector<probe *> result;
220 
221   if (!objfile->sf || !objfile->sf->sym_probe_fns)
222     return result;
223 
224   const std::vector<std::unique_ptr<probe>> &probes
225     = objfile->sf->sym_probe_fns->sym_get_probes (objfile);
226   for (auto &p : probes)
227     {
228       if (p->get_provider () != provider)
229 	continue;
230 
231       if (p->get_name () != name)
232 	continue;
233 
234       result.push_back (p.get ());
235     }
236 
237   return result;
238 }
239 
240 /* See definition in probe.h.  */
241 
242 struct bound_probe
243 find_probe_by_pc (CORE_ADDR pc)
244 {
245   struct bound_probe result;
246 
247   result.objfile = NULL;
248   result.prob = NULL;
249 
250   for (objfile *objfile : current_program_space->objfiles ())
251     {
252       if (!objfile->sf || !objfile->sf->sym_probe_fns
253 	  || objfile->sect_index_text == -1)
254 	continue;
255 
256       /* If this proves too inefficient, we can replace with a hash.  */
257       const std::vector<std::unique_ptr<probe>> &probes
258 	= objfile->sf->sym_probe_fns->sym_get_probes (objfile);
259       for (auto &p : probes)
260 	if (p->get_relocated_address (objfile) == pc)
261 	  {
262 	    result.objfile = objfile;
263 	    result.prob = p.get ();
264 	    return result;
265 	  }
266     }
267 
268   return result;
269 }
270 
271 
272 
273 /* Make a vector of probes matching OBJNAME, PROVIDER, and PROBE_NAME.
274    If SPOPS is not &any_static_probe_ops, only probes related to this
275    specific static probe ops will match.  Each argument is a regexp,
276    or NULL, which matches anything.  */
277 
278 static std::vector<bound_probe>
279 collect_probes (const std::string &objname, const std::string &provider,
280 		const std::string &probe_name, const static_probe_ops *spops)
281 {
282   std::vector<bound_probe> result;
283   gdb::optional<compiled_regex> obj_pat, prov_pat, probe_pat;
284 
285   if (!provider.empty ())
286     prov_pat.emplace (provider.c_str (), REG_NOSUB,
287 		      _("Invalid provider regexp"));
288   if (!probe_name.empty ())
289     probe_pat.emplace (probe_name.c_str (), REG_NOSUB,
290 		       _("Invalid probe regexp"));
291   if (!objname.empty ())
292     obj_pat.emplace (objname.c_str (), REG_NOSUB,
293 		     _("Invalid object file regexp"));
294 
295   for (objfile *objfile : current_program_space->objfiles ())
296     {
297       if (! objfile->sf || ! objfile->sf->sym_probe_fns)
298 	continue;
299 
300       if (obj_pat)
301 	{
302 	  if (obj_pat->exec (objfile_name (objfile), 0, NULL, 0) != 0)
303 	    continue;
304 	}
305 
306       const std::vector<std::unique_ptr<probe>> &probes
307 	= objfile->sf->sym_probe_fns->sym_get_probes (objfile);
308 
309       for (auto &p : probes)
310 	{
311 	  if (spops != &any_static_probe_ops && p->get_static_ops () != spops)
312 	    continue;
313 
314 	  if (prov_pat
315 	      && prov_pat->exec (p->get_provider ().c_str (), 0, NULL, 0) != 0)
316 	    continue;
317 
318 	  if (probe_pat
319 	      && probe_pat->exec (p->get_name ().c_str (), 0, NULL, 0) != 0)
320 	    continue;
321 
322 	  result.emplace_back (p.get (), objfile);
323 	}
324     }
325 
326   return result;
327 }
328 
329 /* A qsort comparison function for bound_probe_s objects.  */
330 
331 static bool
332 compare_probes (const bound_probe &a, const bound_probe &b)
333 {
334   int v;
335 
336   v = a.prob->get_provider ().compare (b.prob->get_provider ());
337   if (v != 0)
338     return v < 0;
339 
340   v = a.prob->get_name ().compare (b.prob->get_name ());
341   if (v != 0)
342     return v < 0;
343 
344   if (a.prob->get_address () != b.prob->get_address ())
345     return a.prob->get_address () < b.prob->get_address ();
346 
347   return strcmp (objfile_name (a.objfile), objfile_name (b.objfile)) < 0;
348 }
349 
350 /* Helper function that generate entries in the ui_out table being
351    crafted by `info_probes_for_ops'.  */
352 
353 static void
354 gen_ui_out_table_header_info (const std::vector<bound_probe> &probes,
355 			      const static_probe_ops *spops)
356 {
357   /* `headings' refers to the names of the columns when printing `info
358      probes'.  */
359   gdb_assert (spops != NULL);
360 
361   std::vector<struct info_probe_column> headings
362     = spops->gen_info_probes_table_header ();
363 
364   for (const info_probe_column &column : headings)
365     {
366       size_t size_max = strlen (column.print_name);
367 
368       for (const bound_probe &probe : probes)
369 	{
370 	  /* `probe_fields' refers to the values of each new field that this
371 	     probe will display.  */
372 
373 	  if (probe.prob->get_static_ops () != spops)
374 	    continue;
375 
376 	  std::vector<const char *> probe_fields
377 	    = probe.prob->gen_info_probes_table_values ();
378 
379 	  gdb_assert (probe_fields.size () == headings.size ());
380 
381 	  for (const char *val : probe_fields)
382 	    {
383 	      /* It is valid to have a NULL value here, which means that the
384 		 backend does not have something to write and this particular
385 		 field should be skipped.  */
386 	      if (val == NULL)
387 		continue;
388 
389 	      size_max = std::max (strlen (val), size_max);
390 	    }
391 	}
392 
393       current_uiout->table_header (size_max, ui_left,
394 				   column.field_name, column.print_name);
395     }
396 }
397 
398 /* Helper function to print not-applicable strings for all the extra
399    columns defined in a static_probe_ops.  */
400 
401 static void
402 print_ui_out_not_applicables (const static_probe_ops *spops)
403 {
404    std::vector<struct info_probe_column> headings
405      = spops->gen_info_probes_table_header ();
406 
407   for (const info_probe_column &column : headings)
408     current_uiout->field_string (column.field_name, _("n/a"));
409 }
410 
411 /* Helper function to print extra information about a probe and an objfile
412    represented by PROBE.  */
413 
414 static void
415 print_ui_out_info (probe *probe)
416 {
417   /* `values' refers to the actual values of each new field in the output
418      of `info probe'.  `headings' refers to the names of each new field.  */
419   gdb_assert (probe != NULL);
420   std::vector<struct info_probe_column> headings
421     = probe->get_static_ops ()->gen_info_probes_table_header ();
422   std::vector<const char *> values
423     = probe->gen_info_probes_table_values ();
424 
425   gdb_assert (headings.size () == values.size ());
426 
427   for (int ix = 0; ix < headings.size (); ++ix)
428     {
429       struct info_probe_column column = headings[ix];
430       const char *val = values[ix];
431 
432       if (val == NULL)
433 	current_uiout->field_skip (column.field_name);
434       else
435 	current_uiout->field_string (column.field_name, val);
436     }
437 }
438 
439 /* Helper function that returns the number of extra fields which POPS will
440    need.  */
441 
442 static int
443 get_number_extra_fields (const static_probe_ops *spops)
444 {
445   return spops->gen_info_probes_table_header ().size ();
446 }
447 
448 /* Helper function that returns true if there is a probe in PROBES
449    featuring the given SPOPS.  It returns false otherwise.  */
450 
451 static bool
452 exists_probe_with_spops (const std::vector<bound_probe> &probes,
453 			 const static_probe_ops *spops)
454 {
455   for (const bound_probe &probe : probes)
456     if (probe.prob->get_static_ops () == spops)
457       return true;
458 
459   return false;
460 }
461 
462 /* Helper function that parses a probe linespec of the form [PROVIDER
463    [PROBE [OBJNAME]]] from the provided string STR.  */
464 
465 static void
466 parse_probe_linespec (const char *str, std::string *provider,
467 		      std::string *probe_name, std::string *objname)
468 {
469   *probe_name = *objname = "";
470 
471   *provider = extract_arg (&str);
472   if (!provider->empty ())
473     {
474       *probe_name = extract_arg (&str);
475       if (!probe_name->empty ())
476 	*objname = extract_arg (&str);
477     }
478 }
479 
480 /* See comment in probe.h.  */
481 
482 void
483 info_probes_for_spops (const char *arg, int from_tty,
484 		       const static_probe_ops *spops)
485 {
486   std::string provider, probe_name, objname;
487   int any_found;
488   int ui_out_extra_fields = 0;
489   size_t size_addr;
490   size_t size_name = strlen ("Name");
491   size_t size_objname = strlen ("Object");
492   size_t size_provider = strlen ("Provider");
493   size_t size_type = strlen ("Type");
494   struct gdbarch *gdbarch = get_current_arch ();
495 
496   parse_probe_linespec (arg, &provider, &probe_name, &objname);
497 
498   std::vector<bound_probe> probes
499     = collect_probes (objname, provider, probe_name, spops);
500 
501   if (spops == &any_static_probe_ops)
502     {
503       /* If SPOPS is &any_static_probe_ops, it means the user has
504 	 requested a "simple" `info probes', i.e., she wants to print
505 	 all information about all probes.  For that, we have to
506 	 identify how many extra fields we will need to add in the
507 	 ui_out table.
508 
509 	 To do that, we iterate over all static_probe_ops, querying
510 	 each one about its extra fields, and incrementing
511 	 `ui_out_extra_fields' to reflect that number.  But note that
512 	 we ignore the static_probe_ops for which no probes are
513 	 defined with the given search criteria.  */
514 
515       for (const static_probe_ops *po : all_static_probe_ops)
516 	if (exists_probe_with_spops (probes, po))
517 	  ui_out_extra_fields += get_number_extra_fields (po);
518     }
519   else
520     ui_out_extra_fields = get_number_extra_fields (spops);
521 
522   {
523     ui_out_emit_table table_emitter (current_uiout,
524 				     5 + ui_out_extra_fields,
525 				     probes.size (), "StaticProbes");
526 
527     std::sort (probes.begin (), probes.end (), compare_probes);
528 
529     /* What's the size of an address in our architecture?  */
530     size_addr = gdbarch_addr_bit (gdbarch) == 64 ? 18 : 10;
531 
532     /* Determining the maximum size of each field (`type', `provider',
533        `name' and `objname').  */
534     for (const bound_probe &probe : probes)
535       {
536 	const char *probe_type = probe.prob->get_static_ops ()->type_name ();
537 
538 	size_type = std::max (strlen (probe_type), size_type);
539 	size_name = std::max (probe.prob->get_name ().size (), size_name);
540 	size_provider = std::max (probe.prob->get_provider ().size (),
541 				  size_provider);
542 	size_objname = std::max (strlen (objfile_name (probe.objfile)),
543 				 size_objname);
544       }
545 
546     current_uiout->table_header (size_type, ui_left, "type", _("Type"));
547     current_uiout->table_header (size_provider, ui_left, "provider",
548 				 _("Provider"));
549     current_uiout->table_header (size_name, ui_left, "name", _("Name"));
550     current_uiout->table_header (size_addr, ui_left, "addr", _("Where"));
551 
552     if (spops == &any_static_probe_ops)
553       {
554 	/* We have to generate the table header for each new probe type
555 	   that we will print.  Note that this excludes probe types not
556 	   having any defined probe with the search criteria.  */
557 	for (const static_probe_ops *po : all_static_probe_ops)
558 	  if (exists_probe_with_spops (probes, po))
559 	    gen_ui_out_table_header_info (probes, po);
560       }
561     else
562       gen_ui_out_table_header_info (probes, spops);
563 
564     current_uiout->table_header (size_objname, ui_left, "object", _("Object"));
565     current_uiout->table_body ();
566 
567     for (const bound_probe &probe : probes)
568       {
569 	const char *probe_type = probe.prob->get_static_ops ()->type_name ();
570 
571 	ui_out_emit_tuple tuple_emitter (current_uiout, "probe");
572 
573 	current_uiout->field_string ("type", probe_type);
574 	current_uiout->field_string ("provider", probe.prob->get_provider ());
575 	current_uiout->field_string ("name", probe.prob->get_name ());
576 	current_uiout->field_core_addr ("addr", probe.prob->get_gdbarch (),
577 					probe.prob->get_relocated_address
578 					(probe.objfile));
579 
580 	if (spops == &any_static_probe_ops)
581 	  {
582 	    for (const static_probe_ops *po : all_static_probe_ops)
583 	      {
584 		if (probe.prob->get_static_ops () == po)
585 		  print_ui_out_info (probe.prob);
586 		else if (exists_probe_with_spops (probes, po))
587 		  print_ui_out_not_applicables (po);
588 	      }
589 	  }
590 	else
591 	  print_ui_out_info (probe.prob);
592 
593 	current_uiout->field_string ("object",
594 				     objfile_name (probe.objfile));
595 	current_uiout->text ("\n");
596       }
597 
598     any_found = !probes.empty ();
599   }
600 
601   if (!any_found)
602     current_uiout->message (_("No probes matched.\n"));
603 }
604 
605 /* Implementation of the `info probes' command.  */
606 
607 static void
608 info_probes_command (const char *arg, int from_tty)
609 {
610   info_probes_for_spops (arg, from_tty, &any_static_probe_ops);
611 }
612 
613 /* Implementation of the `enable probes' command.  */
614 
615 static void
616 enable_probes_command (const char *arg, int from_tty)
617 {
618   std::string provider, probe_name, objname;
619 
620   parse_probe_linespec (arg, &provider, &probe_name, &objname);
621 
622   std::vector<bound_probe> probes
623     = collect_probes (objname, provider, probe_name, &any_static_probe_ops);
624   if (probes.empty ())
625     {
626       current_uiout->message (_("No probes matched.\n"));
627       return;
628     }
629 
630   /* Enable the selected probes, provided their backends support the
631      notion of enabling a probe.  */
632   for (const bound_probe &probe: probes)
633     {
634       if (probe.prob->get_static_ops ()->can_enable ())
635 	{
636 	  probe.prob->enable ();
637 	  current_uiout->message (_("Probe %s:%s enabled.\n"),
638 				  probe.prob->get_provider ().c_str (),
639 				  probe.prob->get_name ().c_str ());
640 	}
641       else
642 	current_uiout->message (_("Probe %s:%s cannot be enabled.\n"),
643 				probe.prob->get_provider ().c_str (),
644 				probe.prob->get_name ().c_str ());
645     }
646 }
647 
648 /* Implementation of the `disable probes' command.  */
649 
650 static void
651 disable_probes_command (const char *arg, int from_tty)
652 {
653   std::string provider, probe_name, objname;
654 
655   parse_probe_linespec (arg, &provider, &probe_name, &objname);
656 
657   std::vector<bound_probe> probes
658     = collect_probes (objname, provider, probe_name, &any_static_probe_ops);
659   if (probes.empty ())
660     {
661       current_uiout->message (_("No probes matched.\n"));
662       return;
663     }
664 
665   /* Disable the selected probes, provided their backends support the
666      notion of enabling a probe.  */
667   for (const bound_probe &probe : probes)
668     {
669       if (probe.prob->get_static_ops ()->can_enable ())
670 	{
671 	  probe.prob->disable ();
672 	  current_uiout->message (_("Probe %s:%s disabled.\n"),
673 				  probe.prob->get_provider ().c_str (),
674 				  probe.prob->get_name ().c_str ());
675 	}
676       else
677 	current_uiout->message (_("Probe %s:%s cannot be disabled.\n"),
678 				probe.prob->get_provider ().c_str (),
679 				probe.prob->get_name ().c_str ());
680     }
681 }
682 
683 /* See comments in probe.h.  */
684 
685 struct value *
686 probe_safe_evaluate_at_pc (frame_info_ptr frame, unsigned n)
687 {
688   struct bound_probe probe;
689   unsigned n_args;
690 
691   probe = find_probe_by_pc (get_frame_pc (frame));
692   if (!probe.prob)
693     return NULL;
694 
695   n_args = probe.prob->get_argument_count (get_frame_arch (frame));
696   if (n >= n_args)
697     return NULL;
698 
699   return probe.prob->evaluate_argument (n, frame);
700 }
701 
702 /* See comment in probe.h.  */
703 
704 const struct static_probe_ops *
705 probe_linespec_to_static_ops (const char **linespecp)
706 {
707   for (const static_probe_ops *ops : all_static_probe_ops)
708     if (ops->is_linespec (linespecp))
709       return ops;
710 
711   return NULL;
712 }
713 
714 /* See comment in probe.h.  */
715 
716 int
717 probe_is_linespec_by_keyword (const char **linespecp, const char *const *keywords)
718 {
719   const char *s = *linespecp;
720   const char *const *csp;
721 
722   for (csp = keywords; *csp; csp++)
723     {
724       const char *keyword = *csp;
725       size_t len = strlen (keyword);
726 
727       if (strncmp (s, keyword, len) == 0 && isspace (s[len]))
728 	{
729 	  *linespecp += len + 1;
730 	  return 1;
731 	}
732     }
733 
734   return 0;
735 }
736 
737 /* Implementation of `is_linespec' method.  */
738 
739 bool
740 any_static_probe_ops::is_linespec (const char **linespecp) const
741 {
742   static const char *const keywords[] = { "-p", "-probe", NULL };
743 
744   return probe_is_linespec_by_keyword (linespecp, keywords);
745 }
746 
747 /* Implementation of 'get_probes' method.  */
748 
749 void
750 any_static_probe_ops::get_probes (std::vector<std::unique_ptr<probe>> *probesp,
751 				  struct objfile *objfile) const
752 {
753   /* No probes can be provided by this dummy backend.  */
754 }
755 
756 /* Implementation of the 'type_name' method.  */
757 
758 const char *
759 any_static_probe_ops::type_name () const
760 {
761   return NULL;
762 }
763 
764 /* Implementation of the 'gen_info_probes_table_header' method.  */
765 
766 std::vector<struct info_probe_column>
767 any_static_probe_ops::gen_info_probes_table_header () const
768 {
769   return std::vector<struct info_probe_column> ();
770 }
771 
772 /* See comments in probe.h.  */
773 
774 struct cmd_list_element **
775 info_probes_cmdlist_get (void)
776 {
777   static struct cmd_list_element *info_probes_cmdlist;
778 
779   if (info_probes_cmdlist == NULL)
780     add_prefix_cmd ("probes", class_info, info_probes_command,
781 		    _("\
782 Show available static probes.\n\
783 Usage: info probes [all|TYPE [ARGS]]\n\
784 TYPE specifies the type of the probe, and can be one of the following:\n\
785   - stap\n\
786 If you specify TYPE, there may be additional arguments needed by the\n\
787 subcommand.\n\
788 If you do not specify any argument, or specify `all', then the command\n\
789 will show information about all types of probes."),
790 		    &info_probes_cmdlist, 0/*allow-unknown*/, &infolist);
791 
792   return &info_probes_cmdlist;
793 }
794 
795 
796 
797 /* This is called to compute the value of one of the $_probe_arg*
798    convenience variables.  */
799 
800 static struct value *
801 compute_probe_arg (struct gdbarch *arch, struct internalvar *ivar,
802 		   void *data)
803 {
804   frame_info_ptr frame = get_selected_frame (_("No frame selected"));
805   CORE_ADDR pc = get_frame_pc (frame);
806   int sel = (int) (uintptr_t) data;
807   struct bound_probe pc_probe;
808   unsigned n_args;
809 
810   /* SEL == -1 means "_probe_argc".  */
811   gdb_assert (sel >= -1);
812 
813   pc_probe = find_probe_by_pc (pc);
814   if (pc_probe.prob == NULL)
815     error (_("No probe at PC %s"), core_addr_to_string (pc));
816 
817   n_args = pc_probe.prob->get_argument_count (arch);
818   if (sel == -1)
819     return value_from_longest (builtin_type (arch)->builtin_int, n_args);
820 
821   if (sel >= n_args)
822     error (_("Invalid probe argument %d -- probe has %u arguments available"),
823 	   sel, n_args);
824 
825   return pc_probe.prob->evaluate_argument (sel, frame);
826 }
827 
828 /* This is called to compile one of the $_probe_arg* convenience
829    variables into an agent expression.  */
830 
831 static void
832 compile_probe_arg (struct internalvar *ivar, struct agent_expr *expr,
833 		   struct axs_value *value, void *data)
834 {
835   CORE_ADDR pc = expr->scope;
836   int sel = (int) (uintptr_t) data;
837   struct bound_probe pc_probe;
838   int n_args;
839 
840   /* SEL == -1 means "_probe_argc".  */
841   gdb_assert (sel >= -1);
842 
843   pc_probe = find_probe_by_pc (pc);
844   if (pc_probe.prob == NULL)
845     error (_("No probe at PC %s"), core_addr_to_string (pc));
846 
847   n_args = pc_probe.prob->get_argument_count (expr->gdbarch);
848 
849   if (sel == -1)
850     {
851       value->kind = axs_rvalue;
852       value->type = builtin_type (expr->gdbarch)->builtin_int;
853       ax_const_l (expr, n_args);
854       return;
855     }
856 
857   gdb_assert (sel >= 0);
858   if (sel >= n_args)
859     error (_("Invalid probe argument %d -- probe has %d arguments available"),
860 	   sel, n_args);
861 
862   pc_probe.prob->compile_to_ax (expr, value, sel);
863 }
864 
865 static const struct internalvar_funcs probe_funcs =
866 {
867   compute_probe_arg,
868   compile_probe_arg,
869 };
870 
871 
872 std::vector<const static_probe_ops *> all_static_probe_ops;
873 
874 void _initialize_probe ();
875 void
876 _initialize_probe ()
877 {
878   all_static_probe_ops.push_back (&any_static_probe_ops);
879 
880   create_internalvar_type_lazy ("_probe_argc", &probe_funcs,
881 				(void *) (uintptr_t) -1);
882   create_internalvar_type_lazy ("_probe_arg0", &probe_funcs,
883 				(void *) (uintptr_t) 0);
884   create_internalvar_type_lazy ("_probe_arg1", &probe_funcs,
885 				(void *) (uintptr_t) 1);
886   create_internalvar_type_lazy ("_probe_arg2", &probe_funcs,
887 				(void *) (uintptr_t) 2);
888   create_internalvar_type_lazy ("_probe_arg3", &probe_funcs,
889 				(void *) (uintptr_t) 3);
890   create_internalvar_type_lazy ("_probe_arg4", &probe_funcs,
891 				(void *) (uintptr_t) 4);
892   create_internalvar_type_lazy ("_probe_arg5", &probe_funcs,
893 				(void *) (uintptr_t) 5);
894   create_internalvar_type_lazy ("_probe_arg6", &probe_funcs,
895 				(void *) (uintptr_t) 6);
896   create_internalvar_type_lazy ("_probe_arg7", &probe_funcs,
897 				(void *) (uintptr_t) 7);
898   create_internalvar_type_lazy ("_probe_arg8", &probe_funcs,
899 				(void *) (uintptr_t) 8);
900   create_internalvar_type_lazy ("_probe_arg9", &probe_funcs,
901 				(void *) (uintptr_t) 9);
902   create_internalvar_type_lazy ("_probe_arg10", &probe_funcs,
903 				(void *) (uintptr_t) 10);
904   create_internalvar_type_lazy ("_probe_arg11", &probe_funcs,
905 				(void *) (uintptr_t) 11);
906 
907   add_cmd ("all", class_info, info_probes_command,
908 	   _("\
909 Show information about all type of probes."),
910 	   info_probes_cmdlist_get ());
911 
912   add_cmd ("probes", class_breakpoint, enable_probes_command, _("\
913 Enable probes.\n\
914 Usage: enable probes [PROVIDER [NAME [OBJECT]]]\n\
915 Each argument is a regular expression, used to select probes.\n\
916 PROVIDER matches probe provider names.\n\
917 NAME matches the probe names.\n\
918 OBJECT matches the executable or shared library name.\n\
919 If you do not specify any argument then the command will enable\n\
920 all defined probes."),
921 	   &enablelist);
922 
923   add_cmd ("probes", class_breakpoint, disable_probes_command, _("\
924 Disable probes.\n\
925 Usage: disable probes [PROVIDER [NAME [OBJECT]]]\n\
926 Each argument is a regular expression, used to select probes.\n\
927 PROVIDER matches probe provider names.\n\
928 NAME matches the probe names.\n\
929 OBJECT matches the executable or shared library name.\n\
930 If you do not specify any argument then the command will disable\n\
931 all defined probes."),
932 	   &disablelist);
933 
934 }
935