1 /* Line completion stuff for GDB, the GNU debugger.
2 Copyright (C) 2000-2001, 2007-2012 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "expression.h"
23 #include "filenames.h" /* For DOSish file names. */
25 #include "gdb_assert.h"
26 #include "exceptions.h"
27 #include "gdb_signals.h"
29 #include "cli/cli-decode.h"
31 /* FIXME: This is needed because of lookup_cmd_1 (). We should be
32 calling a hook instead so we eliminate the CLI dependency. */
35 /* Needed for rl_completer_word_break_characters() and for
36 rl_filename_completion_function. */
37 #include "readline/readline.h"
39 /* readline defines this. */
42 #include "completer.h"
44 /* Prototypes for local functions. */
46 char *line_completion_function (const char *text, int matches,
50 /* readline uses the word breaks for two things:
51 (1) In figuring out where to point the TEXT parameter to the
52 rl_completion_entry_function. Since we don't use TEXT for much,
53 it doesn't matter a lot what the word breaks are for this purpose,
54 but it does affect how much stuff M-? lists.
55 (2) If one of the matches contains a word break character, readline
56 will quote it. That's why we switch between
57 current_language->la_word_break_characters() and
58 gdb_completer_command_word_break_characters. I'm not sure when
59 we need this behavior (perhaps for funky characters in C++
62 /* Variables which are necessary for fancy command line editing. */
64 /* When completing on command names, we remove '-' from the list of
65 word break characters, since we use it in command names. If the
66 readline library sees one in any of the current completion strings,
67 it thinks that the string needs to be quoted and automatically
68 supplies a leading quote. */
69 static char *gdb_completer_command_word_break_characters =
70 " \t\n!@#$%^&*()+=|~`}{[]\"';:?/>.<,";
72 /* When completing on file names, we remove from the list of word
73 break characters any characters that are commonly used in file
74 names, such as '-', '+', '~', etc. Otherwise, readline displays
75 incorrect completion candidates. */
76 #ifdef HAVE_DOS_BASED_FILE_SYSTEM
77 /* MS-DOS and MS-Windows use colon as part of the drive spec, and most
78 programs support @foo style response files. */
79 static char *gdb_completer_file_name_break_characters = " \t\n*|\"';?><@";
81 static char *gdb_completer_file_name_break_characters = " \t\n*|\"';:?><";
84 /* Characters that can be used to quote completion strings. Note that
85 we can't include '"' because the gdb C parser treats such quoted
86 sequences as strings. */
87 static char *gdb_completer_quote_characters = "'";
89 /* Accessor for some completer data that may interest other files. */
92 get_gdb_completer_quote_characters (void)
94 return gdb_completer_quote_characters;
97 /* Line completion interface function for readline. */
100 readline_line_completion_function (const char *text, int matches)
102 return line_completion_function (text, matches,
103 rl_line_buffer, rl_point);
106 /* This can be used for functions which don't want to complete on
107 symbols but don't want to complete on anything else either. */
109 noop_completer (struct cmd_list_element *ignore,
110 char *text, char *prefix)
115 /* Complete on filenames. */
117 filename_completer (struct cmd_list_element *ignore,
118 char *text, char *word)
121 VEC (char_ptr) *return_val = NULL;
128 p = rl_filename_completion_function (text, subsequent_name);
131 /* We need to set subsequent_name to a non-zero value before the
132 continue line below, because otherwise, if the first file
133 seen by GDB is a backup file whose name ends in a `~', we
134 will loop indefinitely. */
136 /* Like emacs, don't complete on old versions. Especially
137 useful in the "source" command. */
138 if (p[strlen (p) - 1] == '~')
145 /* Return exactly p. */
147 else if (word > text)
149 /* Return some portion of p. */
150 q = xmalloc (strlen (p) + 5);
151 strcpy (q, p + (word - text));
156 /* Return some of TEXT plus p. */
157 q = xmalloc (strlen (p) + (text - word) + 5);
158 strncpy (q, word, text - word);
159 q[text - word] = '\0';
163 VEC_safe_push (char_ptr, return_val, q);
166 /* There is no way to do this just long enough to affect quote
167 inserting without also affecting the next completion. This
168 should be fixed in readline. FIXME. */
169 /* Ensure that readline does the right thing
170 with respect to inserting quotes. */
171 rl_completer_word_break_characters = "";
176 /* Complete on locations, which might be of two possible forms:
182 This is intended to be used in commands that set breakpoints
186 location_completer (struct cmd_list_element *ignore,
187 char *text, char *word)
189 int n_syms, n_files, ix;
190 VEC (char_ptr) *fn_list = NULL;
191 VEC (char_ptr) *list = NULL;
194 int quoted = *text == '\'' || *text == '"';
195 int quote_char = '\0';
197 char *file_to_match = NULL;
198 char *symbol_start = text;
199 char *orig_text = text;
202 /* Do we have an unquoted colon, as in "break foo.c::bar"? */
203 for (p = text; *p != '\0'; ++p)
205 if (*p == '\\' && p[1] == '\'')
207 else if (*p == '\'' || *p == '"')
211 while (*p != '\0' && *p != quote_found)
213 if (*p == '\\' && p[1] == quote_found)
218 if (*p == quote_found)
221 break; /* Hit the end of text. */
223 #if HAVE_DOS_BASED_FILE_SYSTEM
224 /* If we have a DOS-style absolute file name at the beginning of
225 TEXT, and the colon after the drive letter is the only colon
226 we found, pretend the colon is not there. */
227 else if (p < text + 3 && *p == ':' && p == text + 1 + quoted)
230 else if (*p == ':' && !colon)
233 symbol_start = p + 1;
235 else if (strchr (current_language->la_word_break_characters(), *p))
236 symbol_start = p + 1;
241 text_len = strlen (text);
243 /* Where is the file name? */
248 file_to_match = (char *) xmalloc (colon - text + 1);
249 strncpy (file_to_match, text, colon - text + 1);
250 /* Remove trailing colons and quotes from the file name. */
251 for (s = file_to_match + (colon - text);
254 if (*s == ':' || *s == quote_char)
257 /* If the text includes a colon, they want completion only on a
258 symbol name after the colon. Otherwise, we need to complete on
259 symbols as well as on files. */
262 list = make_file_symbol_completion_list (symbol_start, word,
264 xfree (file_to_match);
268 list = make_symbol_completion_list (symbol_start, word);
269 /* If text includes characters which cannot appear in a file
270 name, they cannot be asking for completion on files. */
272 gdb_completer_file_name_break_characters) == text_len)
273 fn_list = make_source_files_completion_list (text, text);
276 n_syms = VEC_length (char_ptr, list);
277 n_files = VEC_length (char_ptr, fn_list);
279 /* Catenate fn_list[] onto the end of list[]. */
282 VEC_free (char_ptr, list); /* Paranoia. */
288 for (ix = 0; VEC_iterate (char_ptr, fn_list, ix, p); ++ix)
289 VEC_safe_push (char_ptr, list, p);
290 VEC_free (char_ptr, fn_list);
293 if (n_syms && n_files)
299 /* If we only have file names as possible completion, we should
300 bring them in sync with what rl_complete expects. The
301 problem is that if the user types "break /foo/b TAB", and the
302 possible completions are "/foo/bar" and "/foo/baz"
303 rl_complete expects us to return "bar" and "baz", without the
304 leading directories, as possible completions, because `word'
305 starts at the "b". But we ignore the value of `word' when we
306 call make_source_files_completion_list above (because that
307 would not DTRT when the completion results in both symbols
308 and file names), so make_source_files_completion_list returns
309 the full "/foo/bar" and "/foo/baz" strings. This produces
310 wrong results when, e.g., there's only one possible
311 completion, because rl_complete will prepend "/foo/" to each
312 candidate completion. The loop below removes that leading
314 for (ix = 0; VEC_iterate (char_ptr, list, ix, p); ++ix)
316 memmove (p, p + (word - text),
317 strlen (p) + 1 - (word - text));
322 /* No completions at all. As the final resort, try completing
323 on the entire text as a symbol. */
324 list = make_symbol_completion_list (orig_text, word);
330 /* Helper for expression_completer which recursively adds field and
331 method names from TYPE, a struct or union type, to the array
334 add_struct_fields (struct type *type, VEC (char_ptr) **output,
335 char *fieldname, int namelen)
338 int computed_type_name = 0;
339 const char *type_name = NULL;
341 CHECK_TYPEDEF (type);
342 for (i = 0; i < TYPE_NFIELDS (type); ++i)
344 if (i < TYPE_N_BASECLASSES (type))
345 add_struct_fields (TYPE_BASECLASS (type, i),
346 output, fieldname, namelen);
347 else if (TYPE_FIELD_NAME (type, i))
349 if (TYPE_FIELD_NAME (type, i)[0] != '\0')
351 if (! strncmp (TYPE_FIELD_NAME (type, i),
353 VEC_safe_push (char_ptr, *output,
354 xstrdup (TYPE_FIELD_NAME (type, i)));
356 else if (TYPE_CODE (TYPE_FIELD_TYPE (type, i)) == TYPE_CODE_UNION)
358 /* Recurse into anonymous unions. */
359 add_struct_fields (TYPE_FIELD_TYPE (type, i),
360 output, fieldname, namelen);
365 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
367 const char *name = TYPE_FN_FIELDLIST_NAME (type, i);
369 if (name && ! strncmp (name, fieldname, namelen))
371 if (!computed_type_name)
373 type_name = type_name_no_tag (type);
374 computed_type_name = 1;
376 /* Omit constructors from the completion list. */
377 if (!type_name || strcmp (type_name, name))
378 VEC_safe_push (char_ptr, *output, xstrdup (name));
383 /* Complete on expressions. Often this means completing on symbol
384 names, but some language parsers also have support for completing
387 expression_completer (struct cmd_list_element *ignore,
388 char *text, char *word)
390 struct type *type = NULL;
392 volatile struct gdb_exception except;
394 /* Perform a tentative parse of the expression, to see whether a
395 field completion is required. */
397 TRY_CATCH (except, RETURN_MASK_ERROR)
399 type = parse_field_expression (text, &fieldname);
401 if (except.reason < 0)
403 if (fieldname && type)
407 CHECK_TYPEDEF (type);
408 if (TYPE_CODE (type) != TYPE_CODE_PTR
409 && TYPE_CODE (type) != TYPE_CODE_REF)
411 type = TYPE_TARGET_TYPE (type);
414 if (TYPE_CODE (type) == TYPE_CODE_UNION
415 || TYPE_CODE (type) == TYPE_CODE_STRUCT)
417 int flen = strlen (fieldname);
418 VEC (char_ptr) *result = NULL;
420 add_struct_fields (type, &result, fieldname, flen);
427 /* Commands which complete on locations want to see the entire
430 p > text && p[-1] != ' ' && p[-1] != '\t';
434 /* Not ideal but it is what we used to do before... */
435 return location_completer (ignore, p, word);
438 /* Here are some useful test cases for completion. FIXME: These
439 should be put in the test suite. They should be tested with both
442 "show output-" "radix"
443 "show output" "-radix"
444 "p" ambiguous (commands starting with p--path, print, printf, etc.)
445 "p " ambiguous (all symbols)
446 "info t foo" no completions
447 "info t " no completions
448 "info t" ambiguous ("info target", "info terminal", etc.)
449 "info ajksdlfk" no completions
450 "info ajksdlfk " no completions
452 "info " ambiguous (all info commands)
453 "p \"a" no completions (string constant)
454 "p 'a" ambiguous (all symbols starting with a)
455 "p b-a" ambiguous (all symbols starting with a)
456 "p b-" ambiguous (all symbols)
457 "file Make" "file" (word break hard to screw up here)
458 "file ../gdb.stabs/we" "ird" (needs to not break word at slash)
467 complete_line_internal_reason;
470 /* Internal function used to handle completions.
473 TEXT is the caller's idea of the "word" we are looking at.
475 LINE_BUFFER is available to be looked at; it contains the entire
476 text of the line. POINT is the offset in that line of the cursor.
477 You should pretend that the line ends at POINT.
479 REASON is of type complete_line_internal_reason.
481 If REASON is handle_brkchars:
482 Preliminary phase, called by gdb_completion_word_break_characters
483 function, is used to determine the correct set of chars that are
484 word delimiters depending on the current command in line_buffer.
485 No completion list should be generated; the return value should be
486 NULL. This is checked by an assertion in that function.
488 If REASON is handle_completions:
489 Main phase, called by complete_line function, is used to get the list
490 of posible completions.
492 If REASON is handle_help:
493 Special case when completing a 'help' command. In this case,
494 once sub-command completions are exhausted, we simply return NULL.
497 static VEC (char_ptr) *
498 complete_line_internal (const char *text,
499 char *line_buffer, int point,
500 complete_line_internal_reason reason)
502 VEC (char_ptr) *list = NULL;
503 char *tmp_command, *p;
504 int ignore_help_classes;
505 /* Pointer within tmp_command which corresponds to text. */
507 struct cmd_list_element *c, *result_list;
509 /* Choose the default set of word break characters to break
510 completions. If we later find out that we are doing completions
511 on command strings (as opposed to strings supplied by the
512 individual command completer functions, which can be any string)
513 then we will switch to the special word break set for command
514 strings, which leaves out the '-' character used in some
516 rl_completer_word_break_characters =
517 current_language->la_word_break_characters();
519 /* Decide whether to complete on a list of gdb commands or on
521 tmp_command = (char *) alloca (point + 1);
524 /* The help command should complete help aliases. */
525 ignore_help_classes = reason != handle_help;
527 strncpy (tmp_command, line_buffer, point);
528 tmp_command[point] = '\0';
529 /* Since text always contains some number of characters leading up
530 to point, we can find the equivalent position in tmp_command
531 by subtracting that many characters from the end of tmp_command. */
532 word = tmp_command + point - strlen (text);
536 /* An empty line we want to consider ambiguous; that is, it
537 could be any command. */
538 c = CMD_LIST_AMBIGUOUS;
543 c = lookup_cmd_1 (&p, cmdlist, &result_list, ignore_help_classes);
546 /* Move p up to the next interesting thing. */
547 while (*p == ' ' || *p == '\t')
554 /* It is an unrecognized command. So there are no
555 possible completions. */
558 else if (c == CMD_LIST_AMBIGUOUS)
562 /* lookup_cmd_1 advances p up to the first ambiguous thing, but
563 doesn't advance over that thing itself. Do so now. */
565 while (*q && (isalnum (*q) || *q == '-' || *q == '_'))
567 if (q != tmp_command + point)
569 /* There is something beyond the ambiguous
570 command, so there are no possible completions. For
571 example, "info t " or "info t foo" does not complete
572 to anything, because "info t" can be "info target" or
578 /* We're trying to complete on the command which was ambiguous.
579 This we can deal with. */
582 if (reason != handle_brkchars)
583 list = complete_on_cmdlist (*result_list->prefixlist, p,
584 word, ignore_help_classes);
588 if (reason != handle_brkchars)
589 list = complete_on_cmdlist (cmdlist, p, word,
590 ignore_help_classes);
592 /* Ensure that readline does the right thing with respect to
594 rl_completer_word_break_characters =
595 gdb_completer_command_word_break_characters;
600 /* We've recognized a full command. */
602 if (p == tmp_command + point)
604 /* There is no non-whitespace in the line beyond the
607 if (p[-1] == ' ' || p[-1] == '\t')
609 /* The command is followed by whitespace; we need to
610 complete on whatever comes after command. */
613 /* It is a prefix command; what comes after it is
614 a subcommand (e.g. "info "). */
615 if (reason != handle_brkchars)
616 list = complete_on_cmdlist (*c->prefixlist, p, word,
617 ignore_help_classes);
619 /* Ensure that readline does the right thing
620 with respect to inserting quotes. */
621 rl_completer_word_break_characters =
622 gdb_completer_command_word_break_characters;
624 else if (reason == handle_help)
628 if (reason != handle_brkchars)
629 list = complete_on_enum (c->enums, p, word);
630 rl_completer_word_break_characters =
631 gdb_completer_command_word_break_characters;
635 /* It is a normal command; what comes after it is
636 completed by the command's completer function. */
637 if (c->completer == filename_completer)
639 /* Many commands which want to complete on
640 file names accept several file names, as
641 in "run foo bar >>baz". So we don't want
642 to complete the entire text after the
643 command, just the last word. To this
644 end, we need to find the beginning of the
645 file name by starting at `word' and going
649 && strchr (gdb_completer_file_name_break_characters, p[-1]) == NULL;
652 rl_completer_word_break_characters =
653 gdb_completer_file_name_break_characters;
655 else if (c->completer == location_completer)
657 /* Commands which complete on locations want to
658 see the entire argument. */
661 && p[-1] != ' ' && p[-1] != '\t';
665 if (reason != handle_brkchars && c->completer != NULL)
666 list = (*c->completer) (c, p, word);
671 /* The command is not followed by whitespace; we need to
672 complete on the command itself, e.g. "p" which is a
673 command itself but also can complete to "print", "ptype"
677 /* Find the command we are completing on. */
679 while (q > tmp_command)
681 if (isalnum (q[-1]) || q[-1] == '-' || q[-1] == '_')
687 if (reason != handle_brkchars)
688 list = complete_on_cmdlist (result_list, q, word,
689 ignore_help_classes);
691 /* Ensure that readline does the right thing
692 with respect to inserting quotes. */
693 rl_completer_word_break_characters =
694 gdb_completer_command_word_break_characters;
697 else if (reason == handle_help)
701 /* There is non-whitespace beyond the command. */
703 if (c->prefixlist && !c->allow_unknown)
705 /* It is an unrecognized subcommand of a prefix command,
706 e.g. "info adsfkdj". */
711 if (reason != handle_brkchars)
712 list = complete_on_enum (c->enums, p, word);
716 /* It is a normal command. */
717 if (c->completer == filename_completer)
719 /* See the commentary above about the specifics
720 of file-name completion. */
723 && strchr (gdb_completer_file_name_break_characters,
727 rl_completer_word_break_characters =
728 gdb_completer_file_name_break_characters;
730 else if (c->completer == location_completer)
734 && p[-1] != ' ' && p[-1] != '\t';
738 if (reason != handle_brkchars && c->completer != NULL)
739 list = (*c->completer) (c, p, word);
746 /* Generate completions all at once. Returns a vector of strings.
747 Each element is allocated with xmalloc. It can also return NULL if
748 there are no completions.
750 TEXT is the caller's idea of the "word" we are looking at.
752 LINE_BUFFER is available to be looked at; it contains the entire
755 POINT is the offset in that line of the cursor. You
756 should pretend that the line ends at POINT. */
759 complete_line (const char *text, char *line_buffer, int point)
761 return complete_line_internal (text, line_buffer,
762 point, handle_completions);
765 /* Complete on command names. Used by "help". */
767 command_completer (struct cmd_list_element *ignore,
768 char *text, char *word)
770 return complete_line_internal (word, text,
771 strlen (text), handle_help);
774 /* Complete on signals. */
777 signal_completer (struct cmd_list_element *ignore,
778 char *text, char *word)
781 VEC (char_ptr) *return_val = NULL;
782 size_t len = strlen (word);
783 enum gdb_signal signum;
786 for (signum = GDB_SIGNAL_FIRST; signum != GDB_SIGNAL_LAST; ++signum)
788 /* Can't handle this, so skip it. */
789 if (signum == GDB_SIGNAL_0)
792 signame = gdb_signal_to_name (signum);
794 /* Ignore the unknown signal case. */
795 if (!signame || strcmp (signame, "?") == 0)
798 if (strncasecmp (signame, word, len) == 0)
799 VEC_safe_push (char_ptr, return_val, xstrdup (signame));
805 /* Get the list of chars that are considered as word breaks
806 for the current command. */
809 gdb_completion_word_break_characters (void)
811 VEC (char_ptr) *list;
813 list = complete_line_internal (rl_line_buffer, rl_line_buffer, rl_point,
815 gdb_assert (list == NULL);
816 return rl_completer_word_break_characters;
819 /* Generate completions one by one for the completer. Each time we
820 are called return another potential completion to the caller.
821 line_completion just completes on commands or passes the buck to
822 the command's completer function, the stuff specific to symbol
823 completion is in make_symbol_completion_list.
825 TEXT is the caller's idea of the "word" we are looking at.
827 MATCHES is the number of matches that have currently been collected
828 from calling this completion function. When zero, then we need to
829 initialize, otherwise the initialization has already taken place
830 and we can just return the next potential completion string.
832 LINE_BUFFER is available to be looked at; it contains the entire
833 text of the line. POINT is the offset in that line of the cursor.
834 You should pretend that the line ends at POINT.
836 Returns NULL if there are no more completions, else a pointer to a
837 string which is a possible completion, it is the caller's
838 responsibility to free the string. */
841 line_completion_function (const char *text, int matches,
842 char *line_buffer, int point)
844 static VEC (char_ptr) *list = NULL; /* Cache of completions. */
845 static int index; /* Next cached completion. */
850 /* The caller is beginning to accumulate a new set of
851 completions, so we need to find all of them now, and cache
852 them for returning one at a time on future calls. */
856 /* Free the storage used by LIST, but not by the strings
857 inside. This is because rl_complete_internal () frees
858 the strings. As complete_line may abort by calling
859 `error' clear LIST now. */
860 VEC_free (char_ptr, list);
863 list = complete_line (text, line_buffer, point);
866 /* If we found a list of potential completions during initialization
867 then dole them out one at a time. After returning the last one,
868 return NULL (and continue to do so) each time we are called after
869 that, until a new list is available. */
873 if (index < VEC_length (char_ptr, list))
875 output = VEC_index (char_ptr, list, index);
881 /* Can't do this because readline hasn't yet checked the word breaks
882 for figuring out whether to insert a quote. */
884 /* Make sure the word break characters are set back to normal for
885 the next time that readline tries to complete something. */
886 rl_completer_word_break_characters =
887 current_language->la_word_break_characters();
893 /* Skip over the possibly quoted word STR (as defined by the quote
894 characters QUOTECHARS and the word break characters BREAKCHARS).
895 Returns pointer to the location after the "word". If either
896 QUOTECHARS or BREAKCHARS is NULL, use the same values used by the
900 skip_quoted_chars (char *str, char *quotechars, char *breakchars)
902 char quote_char = '\0';
905 if (quotechars == NULL)
906 quotechars = gdb_completer_quote_characters;
908 if (breakchars == NULL)
909 breakchars = current_language->la_word_break_characters();
911 for (scan = str; *scan != '\0'; scan++)
913 if (quote_char != '\0')
915 /* Ignore everything until the matching close quote char. */
916 if (*scan == quote_char)
918 /* Found matching close quote. */
923 else if (strchr (quotechars, *scan))
925 /* Found start of a quoted string. */
928 else if (strchr (breakchars, *scan))
937 /* Skip over the possibly quoted word STR (as defined by the quote
938 characters and word break characters used by the completer).
939 Returns pointer to the location after the "word". */
942 skip_quoted (char *str)
944 return skip_quoted_chars (str, NULL, NULL);