gdb调试插件
前言
使用gdb进行调试时，最重要的功能就是看变量的当前值。
但是，当这个需求遇到OpenCV中的Mat或者Eigen中的Matrix时，就变得不太好搞。因为这些矩阵很大，又往往被封装的比较复杂，所以直接打印出来对调试而言非常不友好。
因此，便可以借助python对于gdb的支持，来搞一些插件，来优化打印结果。
这里先介绍一下gdb插件加载机制的原理，然后介绍两个目前找到的比较好的插件，分别针对Eigen Matrix和OpenCV Mat打印。
gdb插件加载原理
mark
cv_show插件
该插件可以在gdb调试模式下将cv::Mat数据绘制出来，并且支持放缩，保存，以及像素值的鼠标悬浮显示等功能，还是比较好用的。
具体用法也很简单，首先将以下代码另存为一个python文件，然后在gdb的命令行中source该文件，然后命令行中输入cv_imshow img_name即可图像显示出来。1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265# Copyright (c) 2012, Renato Florentino Garcia <fgarcia.renato@gmail.com>
# Stefano Pellegrini <stefpell@ee.ethz.ch>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# * Neither the name of the authors nor the
# names of its contributors may be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
from builtins import str as text
from builtins import range
import gdb
import matplotlib
matplotlib.use('TKAgg')
import matplotlib.pyplot as pl
import numpy as np
import struct
def chunker(seq, size):
return (seq[pos:pos + size] for pos in range(0, len(seq), size))
class cv_imshow(gdb.Command):
"""Diplays the content of an opencv image"""
def __init__(self):
super(cv_imshow, self).__init__('cv_imshow',
gdb.COMMAND_SUPPORT,
gdb.COMPLETE_SYMBOL)
def invoke (self, arg, from_tty):
# Access the variable from gdb.
args = gdb.string_to_argv(arg)
val = gdb.parse_and_eval(args[0])
if str(val.type.strip_typedefs()) == 'IplImage *':
img_info = self.get_iplimage_info(val)
else:
img_info = self.get_cvmat_info(val)
if img_info: self.show_image(*img_info)
self.dont_repeat()
@staticmethod
def get_cvmat_info(val):
flags = val['flags']
depth = flags & 7
channels = 1 + (flags >> 3) & 63;
if depth == 0:
cv_type_name = 'CV_8U'
data_symbol = 'B'
elif depth == 1:
cv_type_name = 'CV_8S'
data_symbol = 'b'
elif depth == 2:
cv_type_name = 'CV_16U'
data_symbol = 'H'
elif depth == 3:
cv_type_name = 'CV_16S'
data_symbol = 'h'
elif depth == 4:
cv_type_name = 'CV_32S'
data_symbol = 'i'
elif depth == 5:
cv_type_name = 'CV_32F'
data_symbol = 'f'
elif depth == 6:
cv_type_name = 'CV_64F'
data_symbol = 'd'
else:
gdb.write('Unsupported cv::Mat depth\n', gdb.STDERR)
return
rows = val['rows']
cols = val['cols']
line_step = val['step']['p'][0]
gdb.write(cv_type_name + ' with ' + str(channels) + ' channels, ' +
str(rows) + ' rows and ' + str(cols) +' cols\n')
data_address = text(val['data']).encode('utf-8').split()[0]
data_address = int(data_address, 16)
return (cols, rows, channels, line_step, data_address, data_symbol)
@staticmethod
def get_iplimage_info(val):
depth = val['depth']
channels = val['nChannels']
if depth == 0x8:
cv_type_name = 'IPL_DEPTH_8U'
data_symbol = 'B'
elem_size = 1
elif depth == -0x7FFFFFF8:
cv_type_name = 'IPL_DEPTH_8S'
data_symbol = 'b'
elem_size = 1
elif depth == 0x10:
cv_type_name = 'IPL_DEPTH_16U'
data_symbol = 'H'
elem_size = 2
elif depth == -0x7FFFFFF0:
cv_type_name = 'IPL_DEPTH_16S'
data_symbol = 'h'
elem_size = 2
elif depth == -0x7FFFFFE0:
cv_type_name = 'IPL_DEPTH_32S'
data_symbol = 'i'
elem_size = 4
elif depth == 0x20:
cv_type_name = 'IPL_DEPTH_32F'
data_symbol = 'f'
elem_size = 4
elif depth == 0x40:
cv_type_name = 'IPL_DEPTH_64F'
data_symbol = 'd'
elem_size = 8
else:
gdb.write('Unsupported IplImage depth\n', gdb.STDERR)
return
rows = val['height'] if str(val['roi']) == '0x0' else val['roi']['height']
cols = val['width'] if str(val['roi']) == '0x0' else val['roi']['width']
line_step = val['widthStep']
gdb.write(cv_type_name + ' with ' + str(channels) + ' channels, ' +
str(rows) + ' rows and ' + str(cols) +' cols\n')
data_address = text(val['imageData']).encode('utf-8').split()[0]
data_address = int(data_address, 16)
if str(val['roi']) != '0x0':
x_offset = int(val['roi']['xOffset'])
y_offset = int(val['roi']['yOffset'])
data_address += line_step * y_offset + x_offset * elem_size * channels
return (cols, rows, channels, line_step, data_address, data_symbol)
@staticmethod
def show_image(width, height, n_channel, line_step, data_address, data_symbol):
""" Copies the image data to a PIL image and shows it.
Args:
width: The image width, in pixels.
height: The image height, in pixels.
n_channel: The number of channels in image.
line_step: The offset to change to pixel (i+1, j) being
in pixel (i, j), in bytes.
data_address: The address of image data in memory.
data_symbol: Python struct module code to the image data type.
"""
width = int(width)
height = int(height)
n_channel = int(n_channel)
line_step = int(line_step)
data_address = int(data_address)
infe = gdb.inferiors()
memory_data = infe[0].read_memory(data_address, line_step * height)
# Calculate the memory padding to change to the next image line.
# Either due to memory alignment or a ROI.
if data_symbol in ('b', 'B'):
elem_size = 1
elif data_symbol in ('h', 'H'):
elem_size = 2
elif data_symbol in ('i', 'f'):
elem_size = 4
elif data_symbol == 'd':
elem_size = 8
padding = line_step - width * n_channel * elem_size
# Format memory data to load into the image.
image_data = []
if n_channel == 1:
mode = 'L'
fmt = '%d%s%dx' % (width, data_symbol, padding)
for line in chunker(memory_data, line_step):
image_data.extend(struct.unpack(fmt, line))
elif n_channel == 3:
mode = 'RGB'
fmt = '%d%s%dx' % (width * 3, data_symbol, padding)
for line in chunker(memory_data, line_step):
image_data.extend(struct.unpack(fmt, line))
else:
gdb.write('Only 1 or 3 channels supported\n', gdb.STDERR)
return
# Fit the opencv elemente data in the PIL element data
if data_symbol == 'b':
image_data = [i+128 for i in image_data]
elif data_symbol == 'H':
image_data = [i>>8 for i in image_data]
elif data_symbol == 'h':
image_data = [(i+32768)>>8 for i in image_data]
elif data_symbol == 'i':
image_data = [(i+2147483648)>>24 for i in image_data]
elif data_symbol in ('f','d'):
# A float image is discretized in 256 bins for display.
max_image_data = max(image_data)
min_image_data = min(image_data)
img_range = max_image_data - min_image_data
if img_range > 0:
image_data = [int(255 * (i - min_image_data) / img_range) \
for i in image_data]
else:
image_data = [0 for i in image_data]
if n_channel == 3:
# OpenCV stores the channels in BGR mode. Convert to RGB while packing.
image_data = list(zip(*[image_data[i::3] for i in [2, 1, 0]]))
img = None
if mode == 'L':
img = np.reshape(image_data, (height, width)).astype(np.uint8)
elif mode == 'RGB':
img = np.reshape(image_data, (height, width, 3)).astype(np.uint8)
fig = pl.figure()
b = fig.add_subplot(111)
if n_channel == 1:
b.imshow(img, cmap = pl.cm.Greys_r, interpolation='nearest')
elif n_channel == 3:
b.imshow(img, interpolation='nearest')
def format_coord(x, y):
col = int(x+0.5)
row = int(y+0.5)
if col>=0 and col<width and row>=0 and row<height:
if n_channel == 1:
z = img[row,col]
return '(%d, %d), [%1.2f]'%(col, row, z)
elif n_channel == 3:
z0 = img[row,col,0]
z1 = img[row,col,1]
z2 = img[row,col,2]
return '(%d, %d), [%1.2f, %1.2f, %1.2f]'%(col, row, z0, z1, z2)
else:
return 'x=%d, y=%d'%(col, row)
b.format_coord = format_coord
pl.show()
cv_imshow()
Eigen printer
这是Eigen的官方插件，用于Matrix print。
使用方法为:
- 在本地新建一个目录，将以下代码保存到该目录下，命名为printer.py
- 在该目录下另外新建一个空的init.py文件
- 在用户目录下（~下）新建一个.gdbinit文件，文件内容如以下代码头部的相关注释所示，其中的路径要改成上述目录的绝对地址
- 此时，进入gdb调试模式后正常使用print命令即可
- 较大的矩阵，在打印时可能会被默认截断，用
set print elements unlimited取消默认省略机制即可Reference1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315# -*- coding: utf-8 -*-
# This file is part of Eigen, a lightweight C++ template library
# for linear algebra.
#
# Copyright (C) 2009 Benjamin Schindler <bschindler@inf.ethz.ch>
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
# Pretty printers for Eigen::Matrix
# This is still pretty basic as the python extension to gdb is still pretty basic.
# It cannot handle complex eigen types and it doesn't support many of the other eigen types
# This code supports fixed size as well as dynamic size matrices
# To use it:
#
# * Create a directory and put the file as well as an empty __init__.py in
# that directory.
# * Create a ~/.gdbinit file, that contains the following:
# python
# import sys
# sys.path.insert(0, '/path/to/eigen/printer/directory')
# from printers import register_eigen_printers
# register_eigen_printers (None)
# end
import gdb
import re
import itertools
from bisect import bisect_left
# Basic row/column iteration code for use with Sparse and Dense matrices
class _MatrixEntryIterator(object):
def __init__ (self, rows, cols, rowMajor):
self.rows = rows
self.cols = cols
self.currentRow = 0
self.currentCol = 0
self.rowMajor = rowMajor
def __iter__ (self):
return self
def next(self):
return self.__next__() # Python 2.x compatibility
def __next__(self):
row = self.currentRow
col = self.currentCol
if self.rowMajor == 0:
if self.currentCol >= self.cols:
raise StopIteration
self.currentRow = self.currentRow + 1
if self.currentRow >= self.rows:
self.currentRow = 0
self.currentCol = self.currentCol + 1
else:
if self.currentRow >= self.rows:
raise StopIteration
self.currentCol = self.currentCol + 1
if self.currentCol >= self.cols:
self.currentCol = 0
self.currentRow = self.currentRow + 1
return (row, col)
class EigenMatrixPrinter:
"Print Eigen Matrix or Array of some kind"
def __init__(self, variety, val):
"Extract all the necessary information"
# Save the variety (presumably "Matrix" or "Array") for later usage
self.variety = variety
# The gdb extension does not support value template arguments - need to extract them by hand
type = val.type
if type.code == gdb.TYPE_CODE_REF:
type = type.target()
self.type = type.unqualified().strip_typedefs()
tag = self.type.tag
regex = re.compile('\<.*\>')
m = regex.findall(tag)[0][1:-1]
template_params = m.split(',')
template_params = [x.replace(" ", "") for x in template_params]
if template_params[1] == '-0x00000000000000001' or template_params[1] == '-0x000000001' or template_params[1] == '-1':
self.rows = val['m_storage']['m_rows']
else:
self.rows = int(template_params[1])
if template_params[2] == '-0x00000000000000001' or template_params[2] == '-0x000000001' or template_params[2] == '-1':
self.cols = val['m_storage']['m_cols']
else:
self.cols = int(template_params[2])
self.options = 0 # default value
if len(template_params) > 3:
self.options = template_params[3];
self.rowMajor = (int(self.options) & 0x1)
self.innerType = self.type.template_argument(0)
self.val = val
# Fixed size matrices have a struct as their storage, so we need to walk through this
self.data = self.val['m_storage']['m_data']
if self.data.type.code == gdb.TYPE_CODE_STRUCT:
self.data = self.data['array']
self.data = self.data.cast(self.innerType.pointer())
class _iterator(_MatrixEntryIterator):
def __init__ (self, rows, cols, dataPtr, rowMajor):
super(EigenMatrixPrinter._iterator, self).__init__(rows, cols, rowMajor)
self.dataPtr = dataPtr
def __next__(self):
row, col = super(EigenMatrixPrinter._iterator, self).__next__()
item = self.dataPtr.dereference()
self.dataPtr = self.dataPtr + 1
if (self.cols == 1): #if it's a column vector
return ('[%d]' % (row,), item)
elif (self.rows == 1): #if it's a row vector
return ('[%d]' % (col,), item)
return ('[%d,%d]' % (row, col), item)
def children(self):
return self._iterator(self.rows, self.cols, self.data, self.rowMajor)
def to_string(self):
return "Eigen::%s<%s,%d,%d,%s> (data ptr: %s)" % (self.variety, self.innerType, self.rows, self.cols, "RowMajor" if self.rowMajor else "ColMajor", self.data)
class EigenSparseMatrixPrinter:
"Print an Eigen SparseMatrix"
def __init__(self, val):
"Extract all the necessary information"
type = val.type
if type.code == gdb.TYPE_CODE_REF:
type = type.target()
self.type = type.unqualified().strip_typedefs()
tag = self.type.tag
regex = re.compile('\<.*\>')
m = regex.findall(tag)[0][1:-1]
template_params = m.split(',')
template_params = [x.replace(" ", "") for x in template_params]
self.options = 0
if len(template_params) > 1:
self.options = template_params[1];
self.rowMajor = (int(self.options) & 0x1)
self.innerType = self.type.template_argument(0)
self.val = val
self.data = self.val['m_data']
self.data = self.data.cast(self.innerType.pointer())
class _iterator(_MatrixEntryIterator):
def __init__ (self, rows, cols, val, rowMajor):
super(EigenSparseMatrixPrinter._iterator, self).__init__(rows, cols, rowMajor)
self.val = val
def __next__(self):
row, col = super(EigenSparseMatrixPrinter._iterator, self).__next__()
# repeat calculations from SparseMatrix.h:
outer = row if self.rowMajor else col
inner = col if self.rowMajor else row
start = self.val['m_outerIndex'][outer]
end = ((start + self.val['m_innerNonZeros'][outer]) if self.val['m_innerNonZeros'] else
self.val['m_outerIndex'][outer+1])
# and from CompressedStorage.h:
data = self.val['m_data']
if start >= end:
item = 0
elif (end > start) and (inner == data['m_indices'][end-1]):
item = data['m_values'][end-1]
else:
# create Python index list from the target range within m_indices
indices = [data['m_indices'][x] for x in range(int(start), int(end)-1)]
# find the index with binary search
idx = int(start) + bisect_left(indices, inner)
if ((idx < end) and (data['m_indices'][idx] == inner)):
item = data['m_values'][idx]
else:
item = 0
return ('[%d,%d]' % (row, col), item)
def children(self):
if self.data:
return self._iterator(self.rows(), self.cols(), self.val, self.rowMajor)
return iter([]) # empty matrix, for now
def rows(self):
return self.val['m_outerSize'] if self.rowMajor else self.val['m_innerSize']
def cols(self):
return self.val['m_innerSize'] if self.rowMajor else self.val['m_outerSize']
def to_string(self):
if self.data:
status = ("not compressed" if self.val['m_innerNonZeros'] else "compressed")
else:
status = "empty"
dimensions = "%d x %d" % (self.rows(), self.cols())
layout = "row" if self.rowMajor else "column"
return "Eigen::SparseMatrix<%s>, %s, %s major, %s" % (
self.innerType, dimensions, layout, status )
class EigenQuaternionPrinter:
"Print an Eigen Quaternion"
def __init__(self, val):
"Extract all the necessary information"
# The gdb extension does not support value template arguments - need to extract them by hand
type = val.type
if type.code == gdb.TYPE_CODE_REF:
type = type.target()
self.type = type.unqualified().strip_typedefs()
self.innerType = self.type.template_argument(0)
self.val = val
# Quaternions have a struct as their storage, so we need to walk through this
self.data = self.val['m_coeffs']['m_storage']['m_data']['array']
self.data = self.data.cast(self.innerType.pointer())
class _iterator:
def __init__ (self, dataPtr):
self.dataPtr = dataPtr
self.currentElement = 0
self.elementNames = ['x', 'y', 'z', 'w']
def __iter__ (self):
return self
def next(self):
return self.__next__() # Python 2.x compatibility
def __next__(self):
element = self.currentElement
if self.currentElement >= 4: #there are 4 elements in a quanternion
raise StopIteration
self.currentElement = self.currentElement + 1
item = self.dataPtr.dereference()
self.dataPtr = self.dataPtr + 1
return ('[%s]' % (self.elementNames[element],), item)
def children(self):
return self._iterator(self.data)
def to_string(self):
return "Eigen::Quaternion<%s> (data ptr: %s)" % (self.innerType, self.data)
def build_eigen_dictionary ():
pretty_printers_dict[re.compile('^Eigen::Quaternion<.*>$')] = lambda val: EigenQuaternionPrinter(val)
pretty_printers_dict[re.compile('^Eigen::Matrix<.*>$')] = lambda val: EigenMatrixPrinter("Matrix", val)
pretty_printers_dict[re.compile('^Eigen::SparseMatrix<.*>$')] = lambda val: EigenSparseMatrixPrinter(val)
pretty_printers_dict[re.compile('^Eigen::Array<.*>$')] = lambda val: EigenMatrixPrinter("Array", val)
def register_eigen_printers(obj):
"Register eigen pretty-printers with objfile Obj"
if obj == None:
obj = gdb
obj.pretty_printers.append(lookup_function)
def lookup_function(val):
"Look-up and return a pretty-printer that can print va."
type = val.type
if type.code == gdb.TYPE_CODE_REF:
type = type.target()
type = type.unqualified().strip_typedefs()
typename = type.tag
if typename == None:
return None
for function in pretty_printers_dict:
if function.search(typename):
return pretty_printers_dict[function](val)
return None
pretty_printers_dict = {}
build_eigen_dictionary ()
本博客所有文章除特别声明外，均采用 CC BY-SA 4.0 协议 ，转载请注明出处！