gdb/python/lib/gdb/prompt.py

   1 # Extended prompt utilities.
   2 # Copyright (C) 2011-2024 Free Software Foundation, Inc.
   3
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation; either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 """ Extended prompt library functions."""
  18
  19 import gdb
  20 import os
  21
  22
  23 def _prompt_pwd(ignore):
  24     "The current working directory."
  25     return os.getcwd()
  26
  27
  28 def _prompt_object_attr(func, what, attr, nattr):
  29     """Internal worker for fetching GDB attributes."""
  30     if attr is None:
  31         attr = nattr
  32     try:
  33         obj = func()
  34     except gdb.error:
  35         return "<no %s>" % what
  36     if hasattr(obj, attr):
  37         result = getattr(obj, attr)
  38         if callable(result):
  39             result = result()
  40         return result
  41     else:
  42         return "<no attribute %s on current %s>" % (attr, what)
  43
  44
  45 def _prompt_frame(attr):
  46     "The selected frame; an argument names a frame parameter."
  47     return _prompt_object_attr(gdb.selected_frame, "frame", attr, "name")
  48
  49
  50 def _prompt_thread(attr):
  51     "The selected thread; an argument names a thread parameter."
  52     return _prompt_object_attr(gdb.selected_thread, "thread", attr, "num")
  53
  54
  55 def _prompt_version(attr):
  56     "The version of GDB."
  57     return gdb.VERSION
  58
  59
  60 def _prompt_esc(attr):
  61     "The ESC character."
  62     return "\033"
  63
  64
  65 def _prompt_bs(attr):
  66     "A backslash."
  67     return "\\"
  68
  69
  70 def _prompt_n(attr):
  71     "A newline."
  72     return "\n"
  73
  74
  75 def _prompt_r(attr):
  76     "A carriage return."
  77     return "\r"
  78
  79
  80 def _prompt_param(attr):
  81     "A parameter's value; the argument names the parameter."
  82     return gdb.parameter(attr)
  83
  84
  85 def _prompt_noprint_begin(attr):
  86     "Begins a sequence of non-printing characters."
  87     return "\001"
  88
  89
  90 def _prompt_noprint_end(attr):
  91     "Ends a sequence of non-printing characters."
  92     return "\002"
  93
  94
  95 prompt_substitutions = {
  96     "e": _prompt_esc,
  97     "\\": _prompt_bs,
  98     "n": _prompt_n,
  99     "r": _prompt_r,
 100     "v": _prompt_version,
 101     "w": _prompt_pwd,
 102     "f": _prompt_frame,
 103     "t": _prompt_thread,
 104     "p": _prompt_param,
 105     "[": _prompt_noprint_begin,
 106     "]": _prompt_noprint_end,
 107 }
 108
 109
 110 def prompt_help():
 111     """Generate help dynamically from the __doc__ strings of attribute
 112     functions."""
 113
 114     result = ""
 115     keys = sorted(prompt_substitutions.keys())
 116     for key in keys:
 117         result += "  \\%s\t%s\n" % (key, prompt_substitutions[key].__doc__)
 118     result += """
 119 A substitution can be used in a simple form, like "\\f".
 120 An argument can also be passed to it, like "\\f{name}".
 121 The meaning of the argument depends on the particular substitution."""
 122     return result
 123
 124
 125 def substitute_prompt(prompt):
 126     "Perform substitutions on PROMPT."
 127
 128     result = ""
 129     plen = len(prompt)
 130     i = 0
 131     while i < plen:
 132         if prompt[i] == "\\":
 133             i = i + 1
 134             if i >= plen:
 135                 break
 136             cmdch = prompt[i]
 137
 138             if cmdch in prompt_substitutions:
 139                 cmd = prompt_substitutions[cmdch]
 140
 141                 if i + 1 < plen and prompt[i + 1] == "{":
 142                     j = i + 1
 143                     while j < plen and prompt[j] != "}":
 144                         j = j + 1
 145                     # Just ignore formatting errors.
 146                     if j >= plen or prompt[j] != "}":
 147                         arg = None
 148                     else:
 149                         arg = prompt[i + 2 : j]
 150                         i = j
 151                 else:
 152                     arg = None
 153                 result += str(cmd(arg))
 154             else:
 155                 # Unrecognized escapes are turned into the escaped
 156                 # character itself.
 157                 result += prompt[i]
 158         else:
 159             result += prompt[i]
 160
 161         i = i + 1
 162
 163     return result