]>
Commit | Line | Data |
---|---|---|
1d506c26 | 1 | # Copyright (C) 2021-2024 Free Software Foundation, Inc. |
15e15b2d AB |
2 | |
3 | # This program is free software; you can redistribute it and/or modify | |
4 | # it under the terms of the GNU General Public License as published by | |
5 | # the Free Software Foundation; either version 3 of the License, or | |
6 | # (at your option) any later version. | |
7 | # | |
8 | # This program is distributed in the hope that it will be useful, | |
9 | # but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | # GNU General Public License for more details. | |
12 | # | |
13 | # You should have received a copy of the GNU General Public License | |
14 | # along with this program. If not, see <http://www.gnu.org/licenses/>. | |
15 | ||
16 | """Disassembler related module.""" | |
17 | ||
18 | import gdb | |
19 | import _gdb.disassembler | |
20 | ||
21 | # Re-export everything from the _gdb.disassembler module, which is | |
22 | # defined within GDB's C++ code. | |
23 | from _gdb.disassembler import * | |
24 | ||
25 | # Module global dictionary of gdb.disassembler.Disassembler objects. | |
26 | # The keys of this dictionary are bfd architecture names, or the | |
27 | # special value None. | |
28 | # | |
29 | # When a request to disassemble comes in we first lookup the bfd | |
30 | # architecture name from the gdbarch, if that name exists in this | |
31 | # dictionary then we use that Disassembler object. | |
32 | # | |
33 | # If there's no architecture specific disassembler then we look for | |
34 | # the key None in this dictionary, and if that key exists, we use that | |
35 | # disassembler. | |
36 | # | |
37 | # If none of the above checks found a suitable disassembler, then no | |
38 | # disassembly is performed in Python. | |
39 | _disassemblers_dict = {} | |
40 | ||
41 | ||
42 | class Disassembler(object): | |
43 | """A base class from which all user implemented disassemblers must | |
44 | inherit.""" | |
45 | ||
46 | def __init__(self, name): | |
47 | """Constructor. Takes a name, which should be a string, which can be | |
48 | used to identify this disassembler in diagnostic messages.""" | |
49 | self.name = name | |
50 | ||
51 | def __call__(self, info): | |
52 | """A default implementation of __call__. All sub-classes must | |
53 | override this method. Calling this default implementation will throw | |
54 | a NotImplementedError exception.""" | |
55 | raise NotImplementedError("Disassembler.__call__") | |
56 | ||
57 | ||
58 | def register_disassembler(disassembler, architecture=None): | |
59 | """Register a disassembler. DISASSEMBLER is a sub-class of | |
60 | gdb.disassembler.Disassembler. ARCHITECTURE is either None or a | |
61 | string, the name of an architecture known to GDB. | |
62 | ||
63 | DISASSEMBLER is registered as a disassembler for ARCHITECTURE, or | |
64 | all architectures when ARCHITECTURE is None. | |
65 | ||
66 | Returns the previous disassembler registered with this | |
67 | ARCHITECTURE value. | |
68 | """ | |
69 | ||
70 | if not isinstance(disassembler, Disassembler) and disassembler is not None: | |
71 | raise TypeError("disassembler should sub-class gdb.disassembler.Disassembler") | |
72 | ||
73 | old = None | |
74 | if architecture in _disassemblers_dict: | |
75 | old = _disassemblers_dict[architecture] | |
76 | del _disassemblers_dict[architecture] | |
77 | if disassembler is not None: | |
78 | _disassemblers_dict[architecture] = disassembler | |
79 | ||
80 | # Call the private _set_enabled function within the | |
81 | # _gdb.disassembler module. This function sets a global flag | |
82 | # within GDB's C++ code that enables or dissables the Python | |
83 | # disassembler functionality, this improves performance of the | |
84 | # disassembler by avoiding unneeded calls into Python when we know | |
85 | # that no disassemblers are registered. | |
86 | _gdb.disassembler._set_enabled(len(_disassemblers_dict) > 0) | |
87 | return old | |
88 | ||
89 | ||
90 | def _print_insn(info): | |
91 | """This function is called by GDB when it wants to disassemble an | |
92 | instruction. INFO describes the instruction to be | |
93 | disassembled.""" | |
94 | ||
95 | def lookup_disassembler(arch): | |
96 | try: | |
97 | name = arch.name() | |
98 | if name is None: | |
99 | return None | |
100 | if name in _disassemblers_dict: | |
101 | return _disassemblers_dict[name] | |
102 | if None in _disassemblers_dict: | |
103 | return _disassemblers_dict[None] | |
104 | return None | |
105 | except: | |
106 | # It's pretty unlikely this exception case will ever | |
107 | # trigger, one situation would be if the user somehow | |
108 | # corrupted the _disassemblers_dict variable such that it | |
109 | # was no longer a dictionary. | |
110 | return None | |
111 | ||
112 | disassembler = lookup_disassembler(info.architecture) | |
113 | if disassembler is None: | |
114 | return None | |
115 | return disassembler(info) | |
116 | ||
117 | ||
118 | class maint_info_py_disassemblers_cmd(gdb.Command): | |
119 | """ | |
120 | List all registered Python disassemblers. | |
121 | ||
122 | List the name of all registered Python disassemblers, next to the | |
123 | name of the architecture for which the disassembler is registered. | |
124 | ||
125 | The global Python disassembler is listed next to the string | |
126 | 'GLOBAL'. | |
127 | ||
128 | The disassembler that matches the architecture of the currently | |
129 | selected inferior will be marked, this is an indication of which | |
130 | disassembler will be invoked if any disassembly is performed in | |
131 | the current inferior. | |
132 | """ | |
133 | ||
134 | def __init__(self): | |
135 | super().__init__("maintenance info python-disassemblers", gdb.COMMAND_USER) | |
136 | ||
137 | def invoke(self, args, from_tty): | |
138 | # If no disassemblers are registered, tell the user. | |
139 | if len(_disassemblers_dict) == 0: | |
140 | print("No Python disassemblers registered.") | |
141 | return | |
142 | ||
143 | # Figure out the longest architecture name, so we can | |
144 | # correctly format the table of results. | |
145 | longest_arch_name = 0 | |
146 | for architecture in _disassemblers_dict: | |
147 | if architecture is not None: | |
148 | name = _disassemblers_dict[architecture].name | |
149 | if len(name) > longest_arch_name: | |
150 | longest_arch_name = len(name) | |
151 | ||
152 | # Figure out the name of the current architecture. There | |
153 | # should always be a current inferior, but if, somehow, there | |
154 | # isn't, then leave curr_arch as the empty string, which will | |
155 | # not then match agaisnt any architecture in the dictionary. | |
156 | curr_arch = "" | |
157 | if gdb.selected_inferior() is not None: | |
158 | curr_arch = gdb.selected_inferior().architecture().name() | |
159 | ||
160 | # Now print the dictionary of registered disassemblers out to | |
161 | # the user. | |
162 | match_tag = "\t(Matches current architecture)" | |
163 | fmt_len = max(longest_arch_name, len("Architecture")) | |
164 | format_string = "{:" + str(fmt_len) + "s} {:s}" | |
165 | print(format_string.format("Architecture", "Disassember Name")) | |
166 | for architecture in _disassemblers_dict: | |
167 | if architecture is not None: | |
168 | name = _disassemblers_dict[architecture].name | |
169 | if architecture == curr_arch: | |
170 | name += match_tag | |
171 | match_tag = "" | |
172 | print(format_string.format(architecture, name)) | |
173 | if None in _disassemblers_dict: | |
174 | name = _disassemblers_dict[None].name + match_tag | |
175 | print(format_string.format("GLOBAL", name)) | |
176 | ||
177 | ||
178 | maint_info_py_disassemblers_cmd() |