如何交叉编译C++并构建成python库

如何交叉编译C++并构建成python库

1. 交叉编译python

• python版本要和目标平台一致, 本文以python3.10为例

python3 --version
# Python 3.10.12

下载python安装包

wget https://www.python.org/ftp/python/3.10.0/Python-3.10.0.tgz
ls -lh Python-3.10.0.tgz # 查看完整性
tar -xzf Python-3.10.0.tgz

• 编译

mkdir -p /workspace/python3.10-aarch64
cd /workspace/python3.10-aarch64echo "ac_cv_file__dev_ptmx=yes" > /workspace/config.site
echo "ac_cv_file__dev_ptc=yes" >> /workspace/config.site
export CONFIG_SITE=/workspace/config.site/workspace/Python-3.10.0/configure --host=aarch64-linux-gnu --build=x86_64-linux-gnu --prefix=/workspace/python3.10-aarch64/install --enable-shared --enable-ipv6 --disable-static --with-ensurepip=yesmake
make install

2. 交叉编译pybind11

编写交叉编译工具链

aarch64-toolchain.cmake

# aarch64-toolchain.cmake
set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_PROCESSOR aarch64)# 设置交叉编译器
set(CMAKE_C_COMPILER aarch64-linux-gnu-gcc)
set(CMAKE_CXX_COMPILER aarch64-linux-gnu-g++)# 设置路径（根据实际安装路径调整）
# set(CMAKE_FIND_ROOT_PATH /usr/aarch64-linux-gnu)
set(CMAKE_FIND_ROOT_PATH /workspace/python3.10-aarch64/install)# 只在目标平台上查找库和头文件
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)

git clone https://github.com/pybind/pybind11.git
cd pybind11/
mkdir build
cd build
cmake -DCMAKE_TOOLCHAIN_FILE=aarch64-toolchain.cmake -DCMAKE_INSTALL_PREFIX=/workspace/python3.10-aarch64/install ..make
make install

3. 交叉编译demo

demo 组成

.
├── CMakeLists.txt
├── aarch64-toolchain.cmake
├── bindings
│   └── python_bindings.cpp
├── build
├── include
│   └── my_math_lib
│       └── math_operations.h
├── src
│   └── math_operations.cpp
└── test.py

math_operations.h

// include/my_math_lib/math_operations.h#ifndef MY_MATH_LIB_MATH_OPERATIONS_H
#define MY_MATH_LIB_MATH_OPERATIONS_Hnamespace my_math_lib {class MathOperations {
public:int add(int a, int b);int subtract(int a, int b);int multiply(int a, int b);double divide(int a, int b);
};} // namespace my_math_lib#endif // MY_MATH_LIB_MATH_OPERATIONS_H

math_operations.cpp

// src/math_operations.cpp#include "my_math_lib/math_operations.h"
#include <stdexcept>namespace my_math_lib {int MathOperations::add(int a, int b) {return a + b;
}int MathOperations::subtract(int a, int b) {return a - b;
}int MathOperations::multiply(int a, int b) {return a * b;
}double MathOperations::divide(int a, int b) {if (b == 0) {throw std::invalid_argument("Division by zero");}return static_cast<double>(a) / b;
}} // namespace my_math_lib

python_bindings.cpp

// bindings/python_bindings.cpp#include <pybind11/pybind11.h>
#include "my_math_lib/math_operations.h"namespace py = pybind11;PYBIND11_MODULE(my_math_lib, m) {py::class_<my_math_lib::MathOperations>(m, "MathOperations").def(py::init<>()).def("add", &my_math_lib::MathOperations::add).def("subtract", &my_math_lib::MathOperations::subtract).def("multiply", &my_math_lib::MathOperations::multiply).def("divide", &my_math_lib::MathOperations::divide);
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12)
project(MyMathLib)# 设置C++标准
set(CMAKE_CXX_STANDARD 14)# 设置Python路径
set(Python3_ROOT_DIR /workspace/python3.10-aarch64/install)
set(Python3_INCLUDE_DIR /workspace/python3.10-aarch64/install/include/python3.10)
set(Python3_LIBRARY /workspace/python3.10-aarch64/install/lib/libpython3.10.so)# 查找Python3
find_package(Python3 3.10 REQUIRED COMPONENTS Interpreter Development)# 查找pybind11
find_package(pybind11 REQUIRED)# 包含头文件
include_directories(${Python3_INCLUDE_DIRS} /workspace/example/libtest/include)# 添加pybind11模块
pybind11_add_module(my_math_lib MODULE bindings/python_bindings.cpp src/math_operations.cpp)# 链接Python库
target_link_libraries(my_math_lib PRIVATE ${Python3_LIBRARIES})

编译

cmake -DCMAKE_TOOLCHAIN_FILE=../aarch64-toolchain.cmake -DPYTHON_EXECUTABLE=$(which python3.10) ..make

4. python 调用

test.py

import my_math_lib
def main():math_ops = my_math_lib.MathOperations()print(f"Add: 3 + 4 = {math_ops.add(3, 4)}")print(f"Subtract: 10 - 6 = {math_ops.subtract(10, 6)}")print(f"Multiply: 2 * 5 = {math_ops.multiply(2, 5)}")try:print(f"Divide: 8 / 2 = {math_ops.divide(8, 2)}")print(f"Divide: 8 / 0 = {math_ops.divide(8, 0)}")except ValueError as e:print(f"Error: {e}")if __name__ == "__main__":main()

cp my_math_lib.cpython-310-aarch64-linux-gnu.so path/to/lib/
export PYTHONPATH=$PYTHONPATH:path/to/lib
python test.py