1 ubuntu vscode c++配置
建議參考https://blog.csdn.net/weixin_43374723/article/details/84064644,介紹的很詳細。
參考vscode官方介紹https://code.visualstudio.com/docs/cpp/config-linux,補充說明下task.json和launch.json的區別:
- task.json表示編譯時的配置項,生成默認task.json的操作是在某個cpp頁面上使用快捷鍵ctrl+shift+p,打開"任務:運行任務",選擇"c/c++:g++ build active file"可以生成生成默認task.json,其主要內容包括:
label指定了任務的別名,在launch.json中還需要使用;{ "version": "2.0.0", "tasks": [ { "type": "shell", "label": "g++ build active file", "command": "/usr/bin/g++", "args": ["-g", "${file}", "-o", "${fileDirname}/${fileBasenameNoExtension}"], "options": { "cwd": "/usr/bin" }, "problemMatcher": ["$gcc"], "group": { "kind": "build", "isDefault": true } } ] }
command指定了使用g++進行編譯;
args指定了編譯時的參數,各參數的含義可以參考https://code.visualstudio.com/docs/editor/variables-reference和https://www.runoob.com/w3cnote/gcc-parameter-detail.html; - launch.json指定了調試設置,生成默認launch.json可以通過“Run > Add Configuration>選擇C++ (GDB/LLDB)”。默認內容爲:
preLaunchTask指出了在調試之前預先執行的任務,注意這裏和task.json中的label是一樣的,表示在調試之前首先進行編譯;{ "version": "0.2.0", "configurations": [ { "name": "g++ build and debug active file", "type": "cppdbg", "request": "launch", "program": "${fileDirname}/${fileBasenameNoExtension}", "args": [], "stopAtEntry": false, "cwd": "${workspaceFolder}", "environment": [], "externalConsole": false, "MIMode": "gdb", "setupCommands": [ { "description": "Enable pretty-printing for gdb", "text": "-enable-pretty-printing", "ignoreFailures": true } ], "preLaunchTask": "g++ build active file", "miDebuggerPath": "/usr/bin/gdb" } ] }
program指定了要調試哪個程序;
stopAtEntry設置爲true表示在進入main函數時自動進入斷點。
2 同一個文件夾下生成so包並且使用so包
代碼結構:
vscode使用文件夾來管理工程,配置項存儲在.vscode文件下。工程開發時,往往涉及到一個工程中生成so包,另一個工程下調用so包,並單步調試代碼,個人習慣把這兩個工程放到同一個文件夾下進行管理,所以這裏設置gen文件夾下生成so包,use/main.cpp調用so包,通過配置文件來實現不同的任務。
2.1 生成so包時的配置文件
task.json:
{
"version": "2.0.0",
"tasks": [
{
"type": "shell",
"label": "build",
"command": "/usr/bin/g++",
"args": [
"-g", //要設置該選項,否則無法單步調試so包中的代碼
"${workspaceFolder}/gen/hello.cpp", //so包函數實現的文件
"-o",
"${workspaceFolder}/lib/libhello.so", //生成的包一定要是lib+包名+.so的形式
"-fPIC", //生成和位置無關的so文件
"-shared" //生成動態鏈接庫,即so文件
],
"options": {
"cwd": "/usr/bin"
},
"problemMatcher": [
"$gcc"
]
}
]
}
fPIC的含義,請參考:https://www.cnblogs.com/fengliu-/p/10216878.html
shared的含義,請參考:https://www.cnblogs.com/ziyunlong/p/6023121.html,就是創建動態鏈接庫,對應於windows下的dll,所以在運行程序的時候的時候要通過系統的環境變量能找到對應的so文件。
launch.json:
{
// 使用 IntelliSense 瞭解相關屬性。
// 懸停以查看現有屬性的描述。
// 欲瞭解更多信息,請訪問: https://go.microsoft.com/fwlink/?linkid=830387
"version": "0.2.0",
"configurations": [
{
"name": "g++ - 生成和調試活動文件",
"type": "cppdbg",
"request": "launch",
"program": "${workspaceFolder}/lib/libhello.so",//"${fileDirname}/${fileBasenameNoExtension}",
"args": [],
"stopAtEntry": false,
"cwd": "${workspaceFolder}",
"environment": [],
"externalConsole": false,
"MIMode": "gdb",
"setupCommands": [
{
"description": "爲 gdb 啓用整齊打印",
"text": "-enable-pretty-printing",
"ignoreFailures": true
}
],
"preLaunchTask": "build",
"miDebuggerPath": "/usr/bin/gdb"
}
]
}
2.2 調用so包時的配置文件
tasks.json:
{
"version": "2.0.0",
"tasks": [
{
"type": "shell",
"label": "build",
"command": "/usr/bin/g++",
"args": [
"-g",
"${workspaceFolder}/use/main.cpp", //主函數
"-o",
"${workspaceFolder}/lib/main", //生成的可執行文件路徑及名稱
"-I${workspaceFolder}/gen", //頭文件路徑,多個路徑時逗號分割
"-L${workspaceFolder}/lib", //庫文件路徑,多個路徑時逗號分割
"-lhello" //具體的庫文件,這裏是指libhello.so
],
"options": {
"cwd": "/usr/bin"
},
"problemMatcher": [
"$gcc"
]
}
]
}
如果main中需要使用opencv,可以在args中列出:
"-I", "/usr/local/include",
"-I", "/usr/local/include/opencv",
"-I", "/usr/local/include/opencv2",
"-L", "/usr/local/lib",
"-l", "opencv_core",
"-l", "opencv_imgproc",
"-l", "opencv_imgcodecs",
"-l", "opencv_video",
"-l", "opencv_ml",
"-l", "opencv_highgui",
"-l", "opencv_objdetect",
"-l", "opencv_flann",
"-l", "opencv_imgcodecs",
"-l", "opencv_photo",
"-l", "opencv_videoio"
“-l”, “opencv_videoio"和”-lopencv_videoio"是等價的,都是去找/usr/local/lib/libopencv_videoio.so文件。
launch.json:
{
"version": "0.2.0",
"configurations": [
{
"name": "g++ - 生成和調試活動文件",
"type": "cppdbg",
"request": "launch",
"program": "${workspaceFolder}/lib/main",//設置調試的程序名稱
"args": [],
"stopAtEntry": false,
"cwd": "${workspaceFolder}",
"environment": [],
"externalConsole": false,
"MIMode": "gdb",
"setupCommands": [
{
"description": "爲 gdb 啓用整齊打印",
"text": "-enable-pretty-printing",
"ignoreFailures": true
}
],
"preLaunchTask": "build",
"miDebuggerPath": "/usr/bin/gdb"
}
]
}
調用so包時需要能夠讓可執行程序能夠找到這個so包,需要設置~/.bashrc中的LD_LIBRARY_PATH中包含要引用的so包的路徑,然後執行source ~/.bashrc,也可以參考https://blog.csdn.net/arackethis/article/details/43342655獲取更多配置方法。關於Linux共享庫的搜索路徑先後順序可以參考https://blog.csdn.net/rryqszq4/article/details/51142468,這裏摘抄下:
Linux共享庫的搜索路徑先後順序:
1、編譯目標代碼時指定的動態庫搜索路徑:在編譯的時候指定-Wl,-rpath=路徑
2、環境變量LD_LIBRARY_PATH指定的動態庫搜索路徑
3、配置文件/etc/ld.so.conf中指定的動態庫搜索路徑
4、默認的動態庫搜索路徑/lib
5、默認的動態庫搜索路徑 /usr/lib
shell中執行:ldd main可以看看main依賴哪些路徑下的哪些動態鏈接庫;nm -D libhello.so可以查看so包中導出的所有函數。
初次在linux下進行c++的開發,本文記錄簡單的環境配置,以便查詢,後續繼續補充內容,歡迎批評指正。