2011-08-17 Phil Muldoon <pmuldoon@redhat.com>

Tom Tromey  <tromey@redhat.com>
            Matt Rice <ratmice@gmail.com>

        * python/lib/gdb/prompt.py: New file.
        * python/lib/gdb/command/prompt.py: New file.
        * NEWS: Document set extended-prompt and gdb.prompt library

2011-08-17  Phil Muldoon  <pmuldoon@redhat.com>

        * gdb.texinfo (Prompt): Add set/show extended-prompt
        documentation
        (Basic Python): Add prompt_hook anchor.
        (Python modules): Reword module text to reflect multiple modules.
        (gdb.prompt): Document gdb.prompt module.

2011-08-17  Phil Muldoon  <pmuldoon@redhat.com>

        * gdb.python/python.exp: Add extended-prompt tests.

gdb/python/lib/gdb/command/prompt.py

@@ -0,0 +1,66 @@
+# Extended prompt.
+# Copyright (C) 2011 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""GDB command for working with extended prompts."""
+
+import gdb
+import gdb.prompt
+
+class _ExtendedPrompt(gdb.Parameter):
+
+    """Set the extended prompt.
+
+Usage: set extended-prompt VALUE
+
+Substitutions are applied to VALUE to compute the real prompt.
+
+The currently defined substitutions are:
+
+"""
+    # Add the prompt library's dynamically generated help to the
+    # __doc__ string.
+    __doc__ = __doc__ + gdb.prompt.prompt_help()
+
+    set_doc = "Set the extended prompt."
+    show_doc = "Show the extended prompt."
+
+    def __init__(self):
+        super(_ExtendedPrompt, self).__init__("extended-prompt",
+                                              gdb.COMMAND_SUPPORT,
+                                              gdb.PARAM_STRING_NOESCAPE)
+        self.value = ''
+        self.hook_set = False
+
+    def get_show_string (self, pvalue):
+        if self.value is not '':
+           return "The extended prompt is: " + self.value
+        else:
+           return "The extended prompt is not set."
+
+    def get_set_string (self):
+        if self.hook_set == False:
+           gdb.prompt_hook = self.before_prompt_hook
+           self.hook_set = True
+        return ""
+
+    def before_prompt_hook(self, current):
+        if self.value is not '':
+            newprompt = gdb.prompt.substitute_prompt(self.value)
+            return newprompt.replace('\\', '\\\\')
+        else:
+            return None
+
+_ExtendedPrompt()

gdb/python/lib/gdb/prompt.py

@@ -0,0 +1,149 @@
+# Extended prompt utilities.
+# Copyright (C) 2011 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+""" Extended prompt library functions."""
+
+import gdb
+import os
+
+def _prompt_pwd(ignore):
+    "The current working directory."
+    return os.getcwdu()
+
+def _prompt_object_attr(func, what, attr, nattr):
+    """Internal worker for fetching GDB attributes."""
+    if attr is None:
+        attr = nattr
+    try:
+        obj = func()
+    except gdb.error:
+        return '<no %s>' % what
+    if hasattr(obj, attr):
+        result = getattr(obj, attr)
+        if callable(result):
+            result = result()
+        return result
+    else:
+        return '<no attribute %s on current %s>' % (attr, what)
+
+def _prompt_frame(attr):
+    "The selected frame; an argument names a frame parameter."
+    return _prompt_object_attr(gdb.selected_frame, 'frame', attr, 'name')
+
+def _prompt_thread(attr):
+    "The selected thread; an argument names a thread parameter."
+    return _prompt_object_attr(gdb.selected_thread, 'thread', attr, 'num')
+
+def _prompt_version(attr):
+    "The version of GDB."
+    return gdb.VERSION
+
+def _prompt_esc(attr):
+    "The ESC character."
+    return '\033'
+
+def _prompt_bs(attr):
+    "A backslash."
+    return '\\'
+
+def _prompt_n(attr):
+    "A newline."
+    return '\n'
+
+def _prompt_r(attr):
+    "A carriage return."
+    return '\r'
+
+def _prompt_param(attr):
+    "A parameter's value; the argument names the parameter."
+    return gdb.parameter(attr)
+
+def _prompt_noprint_begin(attr):
+    "Begins a sequence of non-printing characters."
+    return '\001'
+
+def _prompt_noprint_end(attr):
+     "Ends a sequence of non-printing characters."
+     return '\002'
+
+prompt_substitutions = {
+    'e': _prompt_esc,
+    '\\': _prompt_bs,
+    'n': _prompt_n,
+    'r': _prompt_r,
+    'v': _prompt_version,
+    'w': _prompt_pwd,
+    'f': _prompt_frame,
+    't': _prompt_thread,
+    'p': _prompt_param,
+    '[': _prompt_noprint_begin,
+    ']': _prompt_noprint_end
+}
+
+def prompt_help():
+    """Generate help dynamically from the __doc__ strings of attribute
+    functions."""
+
+    result = ''
+    keys = prompt_substitutions.keys()
+    keys.sort()
+    for key in keys:
+        result += '  \\%s\t%s\n' % (key, prompt_substitutions[key].__doc__)
+    result += """
+A substitution can be used in a simple form, like "\\f".
+An argument can also be passed to it, like "\\f{name}".
+The meaning of the argument depends on the particular substitution."""
+    return result
+
+def substitute_prompt(prompt):
+    "Perform substitutions on PROMPT."
+
+    result = ''
+    plen = len(prompt)
+    i = 0
+    while i < plen:
+        if prompt[i] == '\\':
+            i = i + 1
+            if i >= plen:
+                break
+            cmdch = prompt[i]
+
+            if cmdch in prompt_substitutions:
+                cmd = prompt_substitutions[cmdch]
+
+                if i + 1 < plen and prompt[i + 1] == '{':
+                    j = i + 1
+                    while j < plen and prompt[j] != '}':
+                        j = j + 1
+                    # Just ignore formatting errors.
+                    if j >= plen or prompt[j] != '}':
+                        arg = None
+                    else:
+                        arg = prompt[i + 2 : j]
+                        i = j
+                else:
+                    arg = None
+                result += str(cmd(arg))
+            else:
+                # Unrecognized escapes are turned into the escaped
+                # character itself.
+                result += prompt[i]
+        else:
+            result += prompt[i]
+
+        i = i + 1
+
+    return result