我将code :: blocks（CB）或visual studio（VS）用于带有特征库的C ++程序。但是，当涉及到调试时，我看不到数组，矩阵等内容。我检查了以下帖子：
Using GDB with Eigen C++ library
我不是C ++专家，但我可以得到我需要的东西叫做打印机。
https://android.googlesource.com/platform/external/eigen/+/b015e75e8c7ba1ab4ddb91e9372a57e76f3fd159/debug/gdb/printers.py有源代码。但是我不知道如何使用这个源代码来调试带有CB或VS中的特征库的gdb。任何想法如何做到这一点？
更新：
vsoftco提到了一个网页https://android.googlesource.com/platform/external/eigen/+/b015e75e8c7ba1ab4ddb91e9372a57e76f3fd159/debug，它为CB和VS提供了gdb的python打印机。如果有人知道如何使用它们来查看特征库数组的内容，请发表评论。
答案 0 :(得分：0)
Eigen::Matrix类不是聚合，因此您不能只使用调试器查看其内容。但是，您应该可以使用调试器，并可以使用cout或其他方法来显示内容。
您提到的链接是gdb的python插件，允许gdb打印Eigen类型的内容。但是当你使用VS（它有内部调试器而不使用gdb）时，没有理由说它可以在你的情况下工作。
您可以尝试切换到MinGW和g ++ / gdb，也可以查看此链接How can I use GDB from inside Visual Studio C++ (Express) to debug my GCC Makefile projects?，了解有关在VS下安装gdb的一些建议。
PS：似乎VS的解决方案也存在，
答案 1 :(得分：0)
gdb的python打印机对我有用。请注意，printers.py脚本是用Python 2.7编写的，并且您的gdb可能正在运行python 3.5或更高版本...使用2to3转换器或将其复制到名为printers3.py的新文件中：
# -*- 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 any of the other eigen types
# Such as quaternion or some other type.
# 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 printers3 import register_eigen_printers
# register_eigen_printers (None)
# end
import gdb
import re
import itertools
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:
def __init__ (self, rows, cols, dataPtr, rowMajor):
self.rows = rows
self.cols = cols
self.dataPtr = dataPtr
self.currentRow = 0
self.currentCol = 0
self.rowMajor = rowMajor
def __iter__ (self):
return self
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
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 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):
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::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 ()