gdb/completer.c - gdb

Global variables defined

Data types defined

Functions defined

Macros defined

Source code

  1. /* Line completion stuff for GDB, the GNU debugger.
  2.    Copyright (C) 2000-2015 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/>.  */

  19. #include "defs.h"
  20. #include "symtab.h"
  21. #include "gdbtypes.h"
  22. #include "expression.h"
  23. #include "filenames.h"                /* For DOSish file names.  */
  24. #include "language.h"
  25. #include "gdb_signals.h"
  26. #include "target.h"
  27. #include "reggroups.h"
  28. #include "user-regs.h"

  30. #include "cli/cli-decode.h"

  32. /* FIXME: This is needed because of lookup_cmd_1 ().  We should be
  33.    calling a hook instead so we eliminate the CLI dependency.  */
  34. #include "gdbcmd.h"

  36. /* Needed for rl_completer_word_break_characters() and for
  37.    rl_filename_completion_function.  */
  38. #include "readline/readline.h"

  40. /* readline defines this.  */
  41. ‌#undef savestring

  43. #include "completer.h"

  45. /* Prototypes for local functions.  */
  46. static
  47. char *line_completion_function (const char *text, int matches,
  48.                                 char *line_buffer,
  49.                                 int point);

  51. /* readline uses the word breaks for two things:
  52.    (1) In figuring out where to point the TEXT parameter to the
  53.    rl_completion_entry_function.  Since we don't use TEXT for much,
  54.    it doesn't matter a lot what the word breaks are for this purpose,
  55.    but it does affect how much stuff M-? lists.
  56.    (2) If one of the matches contains a word break character, readline
  57.    will quote it.  That's why we switch between
  58.    current_language->la_word_break_characters() and
  59.    gdb_completer_command_word_break_characters.  I'm not sure when
  60.    we need this behavior (perhaps for funky characters in C++
  61.    symbols?).  */

  63. /* Variables which are necessary for fancy command line editing.  */

  65. /* When completing on command names, we remove '-' from the list of
  66.    word break characters, since we use it in command names.  If the
  67.    readline library sees one in any of the current completion strings,
  68.    it thinks that the string needs to be quoted and automatically
  69.    supplies a leading quote.  */
  70. ‌static char *gdb_completer_command_word_break_characters =
  71. " \t\n!@#$%^&*()+=|~`}{[]\"';:?/>.<,";

  73. /* When completing on file names, we remove from the list of word
  74.    break characters any characters that are commonly used in file
  75.    names, such as '-', '+', '~', etc.  Otherwise, readline displays
  76.    incorrect completion candidates.  */
  77. #ifdef HAVE_DOS_BASED_FILE_SYSTEM
  78. /* MS-DOS and MS-Windows use colon as part of the drive spec, and most
  79.    programs support @foo style response files.  */
  80. ‌static char *gdb_completer_file_name_break_characters = " \t\n*|\"';?><@";
  81. #else
  82. ‌static char *gdb_completer_file_name_break_characters = " \t\n*|\"';:?><";
  83. #endif

  85. /* Characters that can be used to quote completion strings.  Note that
  86.    we can't include '"' because the gdb C parser treats such quoted
  87.    sequences as strings.  */
  88. ‌static char *gdb_completer_quote_characters = "'";

  90. /* Accessor for some completer data that may interest other files.  */

  92. char *
  93. ‌get_gdb_completer_quote_characters (void)
  94. {
  95.   return gdb_completer_quote_characters;
  96. }

  98. /* Line completion interface function for readline.  */

  100. char *
  101. ‌readline_line_completion_function (const char *text, int matches)
  102. {
  103.   return line_completion_function (text, matches,
  104.                                    rl_line_buffer, rl_point);
  105. }

  107. /* This can be used for functions which don't want to complete on
  108.    symbols but don't want to complete on anything else either.  */
  109. ‌VEC (char_ptr) *
  110. noop_completer (struct cmd_list_element *ignore,
  111.                 const char *text, const char *prefix)
  112. {
  113.   return NULL;
  114. }

  116. /* Complete on filenames.  */
  117. ‌VEC (char_ptr) *
  118. filename_completer (struct cmd_list_element *ignore,
  119.                     const char *text, const char *word)
  120. {
  121.   int subsequent_name;
  122.   VEC (char_ptr) *return_val = NULL;

  124.   subsequent_name = 0;
  125.   while (1)
  126.     {
  127.       char *p, *q;

  129.       p = rl_filename_completion_function (text, subsequent_name);
  130.       if (p == NULL)
  131.         break;
  132.       /* We need to set subsequent_name to a non-zero value before the
  133.          continue line below, because otherwise, if the first file
  134.          seen by GDB is a backup file whose name ends in a `~', we
  135.          will loop indefinitely.  */
  136.       subsequent_name = 1;
  137.       /* Like emacs, don't complete on old versions.  Especially
  138.          useful in the "source" command.  */
  139.       if (p[strlen (p) - 1] == '~')
  140.         {
  141.           xfree (p);
  142.           continue;
  143.         }

  145.       if (word == text)
  146.         /* Return exactly p.  */
  147.         q = p;
  148.       else if (word > text)
  149.         {
  150.           /* Return some portion of p.  */
  151.           q = xmalloc (strlen (p) + 5);
  152.           strcpy (q, p + (word - text));
  153.           xfree (p);
  154.         }
  155.       else
  156.         {
  157.           /* Return some of TEXT plus p.  */
  158.           q = xmalloc (strlen (p) + (text - word) + 5);
  159.           strncpy (q, word, text - word);
  160.           q[text - word] = '\0';
  161.           strcat (q, p);
  162.           xfree (p);
  163.         }
  164.       VEC_safe_push (char_ptr, return_val, q);
  165.     }
  166. #if 0
  167.   /* There is no way to do this just long enough to affect quote
  168.      inserting without also affecting the next completion.  This
  169.      should be fixed in readline.  FIXME.  */
  170.   /* Ensure that readline does the right thing
  171.      with respect to inserting quotes.  */
  172.   rl_completer_word_break_characters = "";
  173. #endif
  174.   return return_val;
  175. }

  177. /* Complete on locations, which might be of two possible forms:

  179.        file:line
  180.    or
  181.        symbol+offset

  183.    This is intended to be used in commands that set breakpoints
  184.    etc.  */

  186. ‌VEC (char_ptr) *
  187. location_completer (struct cmd_list_element *ignore,
  188.                     const char *text, const char *word)
  189. {
  190.   int n_syms, n_files, ix;
  191.   VEC (char_ptr) *fn_list = NULL;
  192.   VEC (char_ptr) *list = NULL;
  193.   const char *p;
  194.   int quote_found = 0;
  195.   int quoted = *text == '\'' || *text == '"';
  196.   int quote_char = '\0';
  197.   const char *colon = NULL;
  198.   char *file_to_match = NULL;
  199.   const char *symbol_start = text;
  200.   const char *orig_text = text;
  201.   size_t text_len;

  203.   /* Do we have an unquoted colon, as in "break foo.c:bar"?  */
  204.   for (p = text; *p != '\0'; ++p)
  205.     {
  206.       if (*p == '\\' && p[1] == '\'')
  207.         p++;
  208.       else if (*p == '\'' || *p == '"')
  209.         {
  210.           quote_found = *p;
  211.           quote_char = *p++;
  212.           while (*p != '\0' && *p != quote_found)
  213.             {
  214.               if (*p == '\\' && p[1] == quote_found)
  215.                 p++;
  216.               p++;
  217.             }

  219.           if (*p == quote_found)
  220.             quote_found = 0;
  221.           else
  222.             break;                /* Hit the end of text.  */
  223.         }
  224. #if HAVE_DOS_BASED_FILE_SYSTEM
  225.       /* If we have a DOS-style absolute file name at the beginning of
  226.          TEXT, and the colon after the drive letter is the only colon
  227.          we found, pretend the colon is not there.  */
  228.       else if (p < text + 3 && *p == ':' && p == text + 1 + quoted)
  229.         ;
  230. #endif
  231.       else if (*p == ':' && !colon)
  232.         {
  233.           colon = p;
  234.           symbol_start = p + 1;
  235.         }
  236.       else if (strchr (current_language->la_word_break_characters(), *p))
  237.         symbol_start = p + 1;
  238.     }

  240.   if (quoted)
  241.     text++;
  242.   text_len = strlen (text);

  244.   /* Where is the file name?  */
  245.   if (colon)
  246.     {
  247.       char *s;

  249.       file_to_match = (char *) xmalloc (colon - text + 1);
  250.       strncpy (file_to_match, text, colon - text + 1);
  251.       /* Remove trailing colons and quotes from the file name.  */
  252.       for (s = file_to_match + (colon - text);
  253.            s > file_to_match;
  254.            s--)
  255.         if (*s == ':' || *s == quote_char)
  256.           *s = '\0';
  257.     }
  258.   /* If the text includes a colon, they want completion only on a
  259.      symbol name after the colon.  Otherwise, we need to complete on
  260.      symbols as well as on files.  */
  261.   if (colon)
  262.     {
  263.       list = make_file_symbol_completion_list (symbol_start, word,
  264.                                                file_to_match);
  265.       xfree (file_to_match);
  266.     }
  267.   else
  268.     {
  269.       list = make_symbol_completion_list (symbol_start, word);
  270.       /* If text includes characters which cannot appear in a file
  271.          name, they cannot be asking for completion on files.  */
  272.       if (strcspn (text,
  273.                    gdb_completer_file_name_break_characters) == text_len)
  274.         fn_list = make_source_files_completion_list (text, text);
  275.     }

  277.   n_syms = VEC_length (char_ptr, list);
  278.   n_files = VEC_length (char_ptr, fn_list);

  280.   /* Catenate fn_list[] onto the end of list[].  */
  281.   if (!n_syms)
  282.     {
  283.       VEC_free (char_ptr, list); /* Paranoia.  */
  284.       list = fn_list;
  285.       fn_list = NULL;
  286.     }
  287.   else
  288.     {
  289.       char *fn;

  291.       for (ix = 0; VEC_iterate (char_ptr, fn_list, ix, fn); ++ix)
  292.         VEC_safe_push (char_ptr, list, fn);
  293.       VEC_free (char_ptr, fn_list);
  294.     }

  296.   if (n_syms && n_files)
  297.     {
  298.       /* Nothing.  */
  299.     }
  300.   else if (n_files)
  301.     {
  302.       char *fn;

  304.       /* If we only have file names as possible completion, we should
  305.          bring them in sync with what rl_complete expects.  The
  306.          problem is that if the user types "break /foo/b TAB", and the
  307.          possible completions are "/foo/bar" and "/foo/baz"
  308.          rl_complete expects us to return "bar" and "baz", without the
  309.          leading directories, as possible completions, because `word'
  310.          starts at the "b".  But we ignore the value of `word' when we
  311.          call make_source_files_completion_list above (because that
  312.          would not DTRT when the completion results in both symbols
  313.          and file names), so make_source_files_completion_list returns
  314.          the full "/foo/bar" and "/foo/baz" strings.  This produces
  315.          wrong results when, e.g., there's only one possible
  316.          completion, because rl_complete will prepend "/foo/" to each
  317.          candidate completion.  The loop below removes that leading
  318.          part.  */
  319.       for (ix = 0; VEC_iterate (char_ptr, list, ix, fn); ++ix)
  320.         {
  321.           memmove (fn, fn + (word - text),
  322.                    strlen (fn) + 1 - (word - text));
  323.         }
  324.     }
  325.   else if (!n_syms)
  326.     {
  327.       /* No completions at all.  As the final resort, try completing
  328.          on the entire text as a symbol.  */
  329.       list = make_symbol_completion_list (orig_text, word);
  330.     }

  332.   return list;
  333. }

  335. /* Helper for expression_completer which recursively adds field and
  336.    method names from TYPE, a struct or union type, to the array
  337.    OUTPUT.  */
  338. static void
  339. ‌add_struct_fields (struct type *type, VEC (char_ptr) **output,
  340.                    char *fieldname, int namelen)
  341. {
  342.   int i;
  343.   int computed_type_name = 0;
  344.   const char *type_name = NULL;

  346.   CHECK_TYPEDEF (type);
  347.   for (i = 0; i < TYPE_NFIELDS (type); ++i)
  348.     {
  349.       if (i < TYPE_N_BASECLASSES (type))
  350.         add_struct_fields (TYPE_BASECLASS (type, i),
  351.                            output, fieldname, namelen);
  352.       else if (TYPE_FIELD_NAME (type, i))
  353.         {
  354.           if (TYPE_FIELD_NAME (type, i)[0] != '\0')
  355.             {
  356.               if (! strncmp (TYPE_FIELD_NAME (type, i),
  357.                              fieldname, namelen))
  358.                 VEC_safe_push (char_ptr, *output,
  359.                                xstrdup (TYPE_FIELD_NAME (type, i)));
  360.             }
  361.           else if (TYPE_CODE (TYPE_FIELD_TYPE (type, i)) == TYPE_CODE_UNION)
  362.             {
  363.               /* Recurse into anonymous unions.  */
  364.               add_struct_fields (TYPE_FIELD_TYPE (type, i),
  365.                                  output, fieldname, namelen);
  366.             }
  367.         }
  368.     }

  370.   for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
  371.     {
  372.       const char *name = TYPE_FN_FIELDLIST_NAME (type, i);

  374.       if (name && ! strncmp (name, fieldname, namelen))
  375.         {
  376.           if (!computed_type_name)
  377.             {
  378.               type_name = type_name_no_tag (type);
  379.               computed_type_name = 1;
  380.             }
  381.           /* Omit constructors from the completion list.  */
  382.           if (!type_name || strcmp (type_name, name))
  383.             VEC_safe_push (char_ptr, *output, xstrdup (name));
  384.         }
  385.     }
  386. }

  388. /* Complete on expressions.  Often this means completing on symbol
  389.    names, but some language parsers also have support for completing
  390.    field names.  */
  391. ‌VEC (char_ptr) *
  392. expression_completer (struct cmd_list_element *ignore,
  393.                       const char *text, const char *word)
  394. {
  395.   struct type *type = NULL;
  396.   char *fieldname;
  397.   const char *p;
  398.   volatile struct gdb_exception except;
  399.   enum type_code code = TYPE_CODE_UNDEF;

  401.   /* Perform a tentative parse of the expression, to see whether a
  402.      field completion is required.  */
  403.   fieldname = NULL;
  404.   TRY_CATCH (except, RETURN_MASK_ERROR)
  405.     {
  406.       type = parse_expression_for_completion (text, &fieldname, &code);
  407.     }
  408.   if (except.reason < 0)
  409.     return NULL;
  410.   if (fieldname && type)
  411.     {
  412.       for (;;)
  413.         {
  414.           CHECK_TYPEDEF (type);
  415.           if (TYPE_CODE (type) != TYPE_CODE_PTR
  416.               && TYPE_CODE (type) != TYPE_CODE_REF)
  417.             break;
  418.           type = TYPE_TARGET_TYPE (type);
  419.         }

  421.       if (TYPE_CODE (type) == TYPE_CODE_UNION
  422.           || TYPE_CODE (type) == TYPE_CODE_STRUCT)
  423.         {
  424.           int flen = strlen (fieldname);
  425.           VEC (char_ptr) *result = NULL;

  427.           add_struct_fields (type, &result, fieldname, flen);
  428.           xfree (fieldname);
  429.           return result;
  430.         }
  431.     }
  432.   else if (fieldname && code != TYPE_CODE_UNDEF)
  433.     {
  434.       VEC (char_ptr) *result;
  435.       struct cleanup *cleanup = make_cleanup (xfree, fieldname);

  437.       result = make_symbol_completion_type (fieldname, fieldname, code);
  438.       do_cleanups (cleanup);
  439.       return result;
  440.     }
  441.   xfree (fieldname);

  443.   /* Commands which complete on locations want to see the entire
  444.      argument.  */
  445.   for (p = word;
  446.        p > text && p[-1] != ' ' && p[-1] != '\t';
  447.        p--)
  448.     ;

  450.   /* Not ideal but it is what we used to do before...  */
  451.   return location_completer (ignore, p, word);
  452. }

  454. /* See definition in completer.h.  */

  456. void
  457. ‌set_gdb_completion_word_break_characters (completer_ftype *fn)
  458. {
  459.   /* So far we are only interested in differentiating filename
  460.      completers from everything else.  */
  461.   if (fn == filename_completer)
  462.     rl_completer_word_break_characters
  463.       = gdb_completer_file_name_break_characters;
  464.   else
  465.     rl_completer_word_break_characters
  466.       = gdb_completer_command_word_break_characters;
  467. }

  469. /* Here are some useful test cases for completion.  FIXME: These
  470.    should be put in the test suite.  They should be tested with both
  471.    M-? and TAB.

  473.    "show output-" "radix"
  474.    "show output" "-radix"
  475.    "p" ambiguous (commands starting with p--path, print, printf, etc.)
  476.    "p "  ambiguous (all symbols)
  477.    "info t foo" no completions
  478.    "info t " no completions
  479.    "info t" ambiguous ("info target", "info terminal", etc.)
  480.    "info ajksdlfk" no completions
  481.    "info ajksdlfk " no completions
  482.    "info" " "
  483.    "info " ambiguous (all info commands)
  484.    "p \"a" no completions (string constant)
  485.    "p 'a" ambiguous (all symbols starting with a)
  486.    "p b-a" ambiguous (all symbols starting with a)
  487.    "p b-" ambiguous (all symbols)
  488.    "file Make" "file" (word break hard to screw up here)
  489.    "file ../gdb.stabs/we" "ird" (needs to not break word at slash)
  490. */

  492. typedef enum
  493. {
  494.   handle_brkchars,
  495.   handle_completions,
  496.   handle_help
  497. }
  498. ‌complete_line_internal_reason;


  501. /* Internal function used to handle completions.


  504.    TEXT is the caller's idea of the "word" we are looking at.

  506.    LINE_BUFFER is available to be looked at; it contains the entire
  507.    text of the line.  POINT is the offset in that line of the cursor.
  508.    You should pretend that the line ends at POINT.

  510.    REASON is of type complete_line_internal_reason.

  512.    If REASON is handle_brkchars:
  513.    Preliminary phase, called by gdb_completion_word_break_characters
  514.    function, is used to determine the correct set of chars that are
  515.    word delimiters depending on the current command in line_buffer.
  516.    No completion list should be generated; the return value should be
  517.    NULL.  This is checked by an assertion in that function.

  519.    If REASON is handle_completions:
  520.    Main phase, called by complete_line function, is used to get the list
  521.    of posible completions.

  523.    If REASON is handle_help:
  524.    Special case when completing a 'help' command.  In this case,
  525.    once sub-command completions are exhausted, we simply return NULL.
  526. */

  528. ‌static VEC (char_ptr) *
  529. complete_line_internal (const char *text,
  530.                         const char *line_buffer, int point,
  531.                         complete_line_internal_reason reason)
  532. {
  533.   VEC (char_ptr) *list = NULL;
  534.   char *tmp_command;
  535.   const char *p;
  536.   int ignore_help_classes;
  537.   /* Pointer within tmp_command which corresponds to text.  */
  538.   char *word;
  539.   struct cmd_list_element *c, *result_list;

  541.   /* Choose the default set of word break characters to break
  542.      completions.  If we later find out that we are doing completions
  543.      on command strings (as opposed to strings supplied by the
  544.      individual command completer functions, which can be any string)
  545.      then we will switch to the special word break set for command
  546.      strings, which leaves out the '-' character used in some
  547.      commands.  */
  548.   rl_completer_word_break_characters =
  549.     current_language->la_word_break_characters();

  551.   /* Decide whether to complete on a list of gdb commands or on
  552.      symbols.  */
  553.   tmp_command = (char *) alloca (point + 1);
  554.   p = tmp_command;

  556.   /* The help command should complete help aliases.  */
  557.   ignore_help_classes = reason != handle_help;

  559.   strncpy (tmp_command, line_buffer, point);
  560.   tmp_command[point] = '\0';
  561.   /* Since text always contains some number of characters leading up
  562.      to point, we can find the equivalent position in tmp_command
  563.      by subtracting that many characters from the end of tmp_command.  */
  564.   word = tmp_command + point - strlen (text);

  566.   if (point == 0)
  567.     {
  568.       /* An empty line we want to consider ambiguous; that is, it
  569.          could be any command.  */
  570.       c = CMD_LIST_AMBIGUOUS;
  571.       result_list = 0;
  572.     }
  573.   else
  574.     {
  575.       c = lookup_cmd_1 (&p, cmdlist, &result_list, ignore_help_classes);
  576.     }

  578.   /* Move p up to the next interesting thing.  */
  579.   while (*p == ' ' || *p == '\t')
  580.     {
  581.       p++;
  582.     }

  584.   if (!c)
  585.     {
  586.       /* It is an unrecognized command.  So there are no
  587.          possible completions.  */
  588.       list = NULL;
  589.     }
  590.   else if (c == CMD_LIST_AMBIGUOUS)
  591.     {
  592.       const char *q;

  594.       /* lookup_cmd_1 advances p up to the first ambiguous thing, but
  595.          doesn't advance over that thing itself.  Do so now.  */
  596.       q = p;
  597.       while (*q && (isalnum (*q) || *q == '-' || *q == '_'))
  598.         ++q;
  599.       if (q != tmp_command + point)
  600.         {
  601.           /* There is something beyond the ambiguous
  602.              command, so there are no possible completions.  For
  603.              example, "info t " or "info t foo" does not complete
  604.              to anything, because "info t" can be "info target" or
  605.              "info terminal".  */
  606.           list = NULL;
  607.         }
  608.       else
  609.         {
  610.           /* We're trying to complete on the command which was ambiguous.
  611.              This we can deal with.  */
  612.           if (result_list)
  613.             {
  614.               if (reason != handle_brkchars)
  615.                 list = complete_on_cmdlist (*result_list->prefixlist, p,
  616.                                             word, ignore_help_classes);
  617.             }
  618.           else
  619.             {
  620.               if (reason != handle_brkchars)
  621.                 list = complete_on_cmdlist (cmdlist, p, word,
  622.                                             ignore_help_classes);
  623.             }
  624.           /* Ensure that readline does the right thing with respect to
  625.              inserting quotes.  */
  626.           rl_completer_word_break_characters =
  627.             gdb_completer_command_word_break_characters;
  628.         }
  629.     }
  630.   else
  631.     {
  632.       /* We've recognized a full command.  */

  634.       if (p == tmp_command + point)
  635.         {
  636.           /* There is no non-whitespace in the line beyond the
  637.              command.  */

  639.           if (p[-1] == ' ' || p[-1] == '\t')
  640.             {
  641.               /* The command is followed by whitespace; we need to
  642.                  complete on whatever comes after command.  */
  643.               if (c->prefixlist)
  644.                 {
  645.                   /* It is a prefix command; what comes after it is
  646.                      a subcommand (e.g. "info ").  */
  647.                   if (reason != handle_brkchars)
  648.                     list = complete_on_cmdlist (*c->prefixlist, p, word,
  649.                                                 ignore_help_classes);

  651.                   /* Ensure that readline does the right thing
  652.                      with respect to inserting quotes.  */
  653.                   rl_completer_word_break_characters =
  654.                     gdb_completer_command_word_break_characters;
  655.                 }
  656.               else if (reason == handle_help)
  657.                 list = NULL;
  658.               else if (c->enums)
  659.                 {
  660.                   if (reason != handle_brkchars)
  661.                     list = complete_on_enum (c->enums, p, word);
  662.                   rl_completer_word_break_characters =
  663.                     gdb_completer_command_word_break_characters;
  664.                 }
  665.               else
  666.                 {
  667.                   /* It is a normal command; what comes after it is
  668.                      completed by the command's completer function.  */
  669.                   if (c->completer == filename_completer)
  670.                     {
  671.                       /* Many commands which want to complete on
  672.                          file names accept several file names, as
  673.                          in "run foo bar >>baz".  So we don't want
  674.                          to complete the entire text after the
  675.                          command, just the last word.  To this
  676.                          end, we need to find the beginning of the
  677.                          file name by starting at `word' and going
  678.                          backwards.  */
  679.                       for (p = word;
  680.                            p > tmp_command
  681.                              && strchr (gdb_completer_file_name_break_characters, p[-1]) == NULL;
  682.                            p--)
  683.                         ;
  684.                       rl_completer_word_break_characters =
  685.                         gdb_completer_file_name_break_characters;
  686.                     }
  687.                   else if (c->completer == location_completer)
  688.                     {
  689.                       /* Commands which complete on locations want to
  690.                          see the entire argument.  */
  691.                       for (p = word;
  692.                            p > tmp_command
  693.                              && p[-1] != ' ' && p[-1] != '\t';
  694.                            p--)
  695.                         ;
  696.                     }
  697.                   if (reason == handle_brkchars
  698.                       && c->completer_handle_brkchars != NULL)
  699.                     (*c->completer_handle_brkchars) (c, p, word);
  700.                   if (reason != handle_brkchars && c->completer != NULL)
  701.                     list = (*c->completer) (c, p, word);
  702.                 }
  703.             }
  704.           else
  705.             {
  706.               /* The command is not followed by whitespace; we need to
  707.                  complete on the command itself, e.g. "p" which is a
  708.                  command itself but also can complete to "print", "ptype"
  709.                  etc.  */
  710.               const char *q;

  712.               /* Find the command we are completing on.  */
  713.               q = p;
  714.               while (q > tmp_command)
  715.                 {
  716.                   if (isalnum (q[-1]) || q[-1] == '-' || q[-1] == '_')
  717.                     --q;
  718.                   else
  719.                     break;
  720.                 }

  722.               if (reason != handle_brkchars)
  723.                 list = complete_on_cmdlist (result_list, q, word,
  724.                                             ignore_help_classes);

  726.               /* Ensure that readline does the right thing
  727.                  with respect to inserting quotes.  */
  728.               rl_completer_word_break_characters =
  729.                 gdb_completer_command_word_break_characters;
  730.             }
  731.         }
  732.       else if (reason == handle_help)
  733.         list = NULL;
  734.       else
  735.         {
  736.           /* There is non-whitespace beyond the command.  */

  738.           if (c->prefixlist && !c->allow_unknown)
  739.             {
  740.               /* It is an unrecognized subcommand of a prefix command,
  741.                  e.g. "info adsfkdj".  */
  742.               list = NULL;
  743.             }
  744.           else if (c->enums)
  745.             {
  746.               if (reason != handle_brkchars)
  747.                 list = complete_on_enum (c->enums, p, word);
  748.             }
  749.           else
  750.             {
  751.               /* It is a normal command.  */
  752.               if (c->completer == filename_completer)
  753.                 {
  754.                   /* See the commentary above about the specifics
  755.                      of file-name completion.  */
  756.                   for (p = word;
  757.                        p > tmp_command
  758.                          && strchr (gdb_completer_file_name_break_characters,
  759.                                     p[-1]) == NULL;
  760.                        p--)
  761.                     ;
  762.                   rl_completer_word_break_characters =
  763.                     gdb_completer_file_name_break_characters;
  764.                 }
  765.               else if (c->completer == location_completer)
  766.                 {
  767.                   for (p = word;
  768.                        p > tmp_command
  769.                          && p[-1] != ' ' && p[-1] != '\t';
  770.                        p--)
  771.                     ;
  772.                 }
  773.               if (reason == handle_brkchars
  774.                   && c->completer_handle_brkchars != NULL)
  775.                 (*c->completer_handle_brkchars) (c, p, word);
  776.               if (reason != handle_brkchars && c->completer != NULL)
  777.                 list = (*c->completer) (c, p, word);
  778.             }
  779.         }
  780.     }

  782.   return list;
  783. }
  784. /* Generate completions all at once.  Returns a vector of strings.
  785.    Each element is allocated with xmalloc.  It can also return NULL if
  786.    there are no completions.

  788.    TEXT is the caller's idea of the "word" we are looking at.

  790.    LINE_BUFFER is available to be looked at; it contains the entire
  791.    text of the line.

  793.    POINT is the offset in that line of the cursor.  You
  794.    should pretend that the line ends at POINT.  */

  796. ‌VEC (char_ptr) *
  797. complete_line (const char *text, const char *line_buffer, int point)
  798. {
  799.   return complete_line_internal (text, line_buffer,
  800.                                  point, handle_completions);
  801. }

  803. /* Complete on command names.  Used by "help".  */
  804. ‌VEC (char_ptr) *
  805. command_completer (struct cmd_list_element *ignore,
  806.                    const char *text, const char *word)
  807. {
  808.   return complete_line_internal (word, text,
  809.                                  strlen (text), handle_help);
  810. }

  812. /* Complete on signals.  */

  814. ‌VEC (char_ptr) *
  815. signal_completer (struct cmd_list_element *ignore,
  816.                   const char *text, const char *word)
  817. {
  818.   VEC (char_ptr) *return_val = NULL;
  819.   size_t len = strlen (word);
  820.   enum gdb_signal signum;
  821.   const char *signame;

  823.   for (signum = GDB_SIGNAL_FIRST; signum != GDB_SIGNAL_LAST; ++signum)
  824.     {
  825.       /* Can't handle this, so skip it.  */
  826.       if (signum == GDB_SIGNAL_0)
  827.         continue;

  829.       signame = gdb_signal_to_name (signum);

  831.       /* Ignore the unknown signal case.  */
  832.       if (!signame || strcmp (signame, "?") == 0)
  833.         continue;

  835.       if (strncasecmp (signame, word, len) == 0)
  836.         VEC_safe_push (char_ptr, return_val, xstrdup (signame));
  837.     }

  839.   return return_val;
  840. }

  842. /* Complete on a register or reggroup.  */

  844. ‌VEC (char_ptr) *
  845. reg_or_group_completer (struct cmd_list_element *ignore,
  846.                         const char *text, const char *word)
  847. {
  848.   VEC (char_ptr) *result = NULL;
  849.   size_t len = strlen (word);
  850.   struct gdbarch *gdbarch;
  851.   struct reggroup *group;
  852.   const char *name;
  853.   int i;

  855.   if (!target_has_registers)
  856.     return result;

  858.   gdbarch = get_frame_arch (get_selected_frame (NULL));

  860.   for (i = 0;
  861.        (name = user_reg_map_regnum_to_name (gdbarch, i)) != NULL;
  862.        i++)
  863.     {
  864.       if (*name != '\0' && strncmp (word, name, len) == 0)
  865.         VEC_safe_push (char_ptr, result, xstrdup (name));
  866.     }

  868.   for (group = reggroup_next (gdbarch, NULL);
  869.        group != NULL;
  870.        group = reggroup_next (gdbarch, group))
  871.     {
  872.       name = reggroup_name (group);
  873.       if (strncmp (word, name, len) == 0)
  874.         VEC_safe_push (char_ptr, result, xstrdup (name));
  875.     }

  877.   return result;
  878. }


  881. /* Get the list of chars that are considered as word breaks
  882.    for the current command.  */

  884. char *
  885. ‌gdb_completion_word_break_characters (void)
  886. {
  887.   VEC (char_ptr) *list;

  889.   list = complete_line_internal (rl_line_buffer, rl_line_buffer, rl_point,
  890.                                  handle_brkchars);
  891.   gdb_assert (list == NULL);
  892.   return rl_completer_word_break_characters;
  893. }

  895. /* Generate completions one by one for the completer.  Each time we
  896.    are called return another potential completion to the caller.
  897.    line_completion just completes on commands or passes the buck to
  898.    the command's completer function, the stuff specific to symbol
  899.    completion is in make_symbol_completion_list.

  901.    TEXT is the caller's idea of the "word" we are looking at.

  903.    MATCHES is the number of matches that have currently been collected
  904.    from calling this completion function.  When zero, then we need to
  905.    initialize, otherwise the initialization has already taken place
  906.    and we can just return the next potential completion string.

  908.    LINE_BUFFER is available to be looked at; it contains the entire
  909.    text of the line.  POINT is the offset in that line of the cursor.
  910.    You should pretend that the line ends at POINT.

  912.    Returns NULL if there are no more completions, else a pointer to a
  913.    string which is a possible completion, it is the caller's
  914.    responsibility to free the string.  */

  916. static char *
  917. ‌line_completion_function (const char *text, int matches,
  918.                           char *line_buffer, int point)
  919. {
  920.   static VEC (char_ptr) *list = NULL;        /* Cache of completions.  */
  921.   static int index;                        /* Next cached completion.  */
  922.   char *output = NULL;

  924.   if (matches == 0)
  925.     {
  926.       /* The caller is beginning to accumulate a new set of
  927.          completions, so we need to find all of them now, and cache
  928.          them for returning one at a time on future calls.  */

  930.       if (list)
  931.         {
  932.           /* Free the storage used by LIST, but not by the strings
  933.              inside.  This is because rl_complete_internal () frees
  934.              the strings.  As complete_line may abort by calling
  935.              `error' clear LIST now.  */
  936.           VEC_free (char_ptr, list);
  937.         }
  938.       index = 0;
  939.       list = complete_line (text, line_buffer, point);
  940.     }

  942.   /* If we found a list of potential completions during initialization
  943.      then dole them out one at a time.  After returning the last one,
  944.      return NULL (and continue to do so) each time we are called after
  945.      that, until a new list is available.  */

  947.   if (list)
  948.     {
  949.       if (index < VEC_length (char_ptr, list))
  950.         {
  951.           output = VEC_index (char_ptr, list, index);
  952.           index++;
  953.         }
  954.     }

  956. #if 0
  957.   /* Can't do this because readline hasn't yet checked the word breaks
  958.      for figuring out whether to insert a quote.  */
  959.   if (output == NULL)
  960.     /* Make sure the word break characters are set back to normal for
  961.        the next time that readline tries to complete something.  */
  962.     rl_completer_word_break_characters =
  963.       current_language->la_word_break_characters();
  964. #endif

  966.   return (output);
  967. }

  969. /* Skip over the possibly quoted word STR (as defined by the quote
  970.    characters QUOTECHARS and the word break characters BREAKCHARS).
  971.    Returns pointer to the location after the "word".  If either
  972.    QUOTECHARS or BREAKCHARS is NULL, use the same values used by the
  973.    completer.  */

  975. const char *
  976. ‌skip_quoted_chars (const char *str, const char *quotechars,
  977.                    const char *breakchars)
  978. {
  979.   char quote_char = '\0';
  980.   const char *scan;

  982.   if (quotechars == NULL)
  983.     quotechars = gdb_completer_quote_characters;

  985.   if (breakchars == NULL)
  986.     breakchars = current_language->la_word_break_characters();

  988.   for (scan = str; *scan != '\0'; scan++)
  989.     {
  990.       if (quote_char != '\0')
  991.         {
  992.           /* Ignore everything until the matching close quote char.  */
  993.           if (*scan == quote_char)
  994.             {
  995.               /* Found matching close quote.  */
  996.               scan++;
  997.               break;
  998.             }
  999.         }
  1000.       else if (strchr (quotechars, *scan))
  1001.         {
  1002.           /* Found start of a quoted string.  */
  1003.           quote_char = *scan;
  1004.         }
  1005.       else if (strchr (breakchars, *scan))
  1006.         {
  1007.           break;
  1008.         }
  1009.     }

  1011.   return (scan);
  1012. }

  1014. /* Skip over the possibly quoted word STR (as defined by the quote
  1015.    characters and word break characters used by the completer).
  1016.    Returns pointer to the location after the "word".  */

  1018. const char *
  1019. ‌skip_quoted (const char *str)
  1020. {
  1021.   return skip_quoted_chars (str, NULL, NULL);
  1022. }