用VScode編寫C++大型專案的方法步驟

sudo apt-get install clang-format

sudo yum install centos-release-scl-rh

sudo yum install llvm-toolset-7-git-clang-format

sudo find / -name *clang-format*
 
...
/opt/rh/llvm-toolset-7/root/usr/bin/clang-format
...

export PATH=$PATH:/opt/rh/llvm-toolset-7/root/usr/bin

clang-format -style=google -dump-config > .clang-format

sudo apt-get install clang-tidy

（1）sudo yum install centos-release-scl
（2）sudo yum install llvm-toolset-7
（3）sudo yum install llvm-toolset-7-clang-analyzer llvm-toolset-7-clang-tools-extra
（4）scl enable llvm-toolset-7 'clang -v'
（5）scl enable llvm-toolset-7 'lldb -v'
（6）scl enable llvm-toolset-7 bash

// 列出所有的check
$ clang-tidy -list-checks -checks='*'
// 找出simple.cc中所有沒有用到的using declarations. 後面的`--`表示這個檔案不在compilation database裡面，可以直接單獨編譯；
$ clang-tidy -checks="-*,misc-unused-using-decls" path/to/simple.cc --
 
// 找出simple.cc中所有沒有用到的using declarations並自動fix(刪除掉)
$ clang-tidy -checks="-*,misc-unused-using-decls" -fix path/to/simple.cc --
 
// 找出a.c中沒有用到的using declarations. 這裡需要path/to/project/compile_commands.json存在
$ clang-tidy -checks="-*,misc-unused-using-decls" path/to/project/a.cc

# .clang-tidy
Checks: '-*,clang-diagnostic-*,llvm-*,misc-*,-misc-unused-parameters,-misc-non-private-member-variables-in-classes,-readability-identifier-naming'
# Note that the readability-identifier-naming check is disabled, there are too
# many violations in the codebase and they create too much noise in clang-tidy
# results.
# Naming settings are kept for documentation purposes and allowing to run the
# check if the users would override this file, e.g. via a command-line arg.
CheckOptions:
  - key:             readability-identifier-naming.ClassCase
    value:           CamelCase
  - key:             readability-identifier-naming.EnumCase
    value:           CamelCase
  - key:             readability-identifier-naming.FunctionCase
    value:           camelBack
  - key:             readability-identifier-naming.MemberCase
    value:           CamelCase
  - key:             readability-identifier-naming.ParameterCase
    value:           CamelCase
  - key:             readability-identifier-naming.UnionCase
    value:           CamelCase
  - key:             readability-identifier-naming.VariableCase
    value:           CamelCase

├── client
│   ├── xxx.cpp
│   ├── ...
├── lib
│   ├── xxx.cpp
│   ├── ...
├── server
│   ├── xxx.cpp
│   ├── ...

# cmake_minimum_required：指定了當前工程支援的cmake最小版本
cmake_minimum_required(VERSION 3.1)
# project：指定工程名稱
project(CProxy)
# CMake 中有一個變數 CMAKE_BUILD_TYPE ,可以的取值是 Debug、Release、RelWithDebInfo和 MinSizeRel。
# 當這個變數值為 Debug 的時候,CMake 會使用變數 CMAKE_CXX_FLAGS_DEBUG 和 CMAKE_C_FLAGS_DEBUG 中的字串作為編譯選項生成 Makefile; 當變數值為Release時，則會使用CMAKE_CXX_FLAGS_RELEASE 和 CMAKE_C_FLAGS_RELEASE 中的字串作為編譯選項生成 Makefile。
SET(CMAKE_BUILD_TYPE "Debug")
# 啟用GDB
SET(CMAKE_CXX_FLAGS_DEBUG "$ENV{CXXFLAGS} -O0 -Wall -g -ggdb")
# 啟用優化（1～3）
SET(CMAKE_CXX_FLAGS_RELEASE "$ENV{CXXFLAGS} -O3 -Wall")
 
# 設定 c++ 編譯器，這裡使用clang++進行編譯
set(CMAKE_CXX_COMPILER "clang++")
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED True)
set(CMAKE_CXX_FLAGS -g -Wall)
 
message(STATUS "CMAKE_CXX_FLAGS: " "${CMAKE_CXX_FLAGS}")
string(REPLACE ";" " " CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
message(STATUS "CMAKE_CXX_FLAGS: " "${CMAKE_CXX_FLAGS}")
 
# include_directories：將指定目錄新增到編譯器的標頭檔案搜尋路徑之下，指定的目錄被解釋成當前原始碼路徑的相對路徑。
# 將工程根目錄新增進來後，在server和client中能通過"lib/xxx"引入lib目錄下的標頭檔案
include_directories(${PROJECT_SOURCE_DIR})
# 新增子目錄，並構建該子目錄。
# 會執行lib、server、client三個目錄中的CMakeLists.txt
add_subdirectory(lib)
add_subdirectory(server)
add_subdirectory(client)

// lib/CMakeLists.txt
set(lib
    Buffer.cpp
    EventLoopThread.cpp
    EventLoopThreadPool.cpp
    Util.cpp
    EventLoop.cpp
    Channel.cpp
    Epoll.cpp
    Msg.cpp
    CtlConn.cpp
    ProxyConn.cpp
)
 
# 將${lib}變數指定的原始檔生成連結檔案
add_library(lib ${lib})
# target_link_libraries：將目標檔案與庫檔案進行連結
# 使用多執行緒需要引入pthread庫，所以將pthread庫連結到上一步建立的lib目標檔案中
target_link_libraries(lib pthread)
 
// client/CMakeLists.txt
# 將client目錄下的所有原始檔都儲存到SOURCE_DIR變數中。 
aux_source_directory(./ SOURCE_DIR)
# 將${SOURCE_DIR}中的所有原始檔編譯成Client可執行檔案
add_executable(Client ${SOURCE_DIR})
# 生成可執行檔案需要連結lib庫
target_link_libraries(Client lib)
 
// Server/CMakeLists.txt
aux_source_directory(./ SOURCE_DIR)
add_executable(Server ${SOURCE_DIR})
target_link_libraries(Server lib)

mkdir build
cd build
cmake ..

make

# 用於輸出clang-tidy需要用到的compile_commands.json檔案
# 這一行需要放在add_subdirectory/aux_source_directory之前
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
set(CLANG_SEARCH_PATH "/usr/local/bin" "/usr/bin" "/usr/local/opt/llvm/bin" "/usr/local/opt/llvm@8/bin" "/usr/local/Cellar/llvm/8.0.1/bin")
if (NOT DEFINED CLANG_TIDY_BIN)
    # attempt to find the binary if user did not specify
    find_program(CLANG_TIDY_BIN
            NAMES clang-tidy clang-fidy-8
            HINTS ${CLANG_SEARCH_PATH})
endif ()
if ("${CLANG_TIDY_BIN}" STREQUAL "CLANG_TIDY_BIN-NOTFOUND")
    message(WARNING "couldn't find clang-tidy.")
else ()
    message(STATUS "found clang-fidy at ${CLANG_TIDY_BIN}")
endif ()
# 新增clang-tidy命令
add_custom_target(clang-tidy COMMAND python ${CMAKE_SOURCE_DIR}/run-clang-tidy.py                              # run LLVM's clang-tidy script
-clang-tidy-binary ${CLANG_TIDY_BIN} # using our clang-tidy binary
-p ${CMAKE_BINARY_DIR}      # using cmake's generated compile commands
)

yum install ccache

find_program(CCACHE_FOUND ccache)
if(CCACHE_FOUND)
    set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE ccache)
    set_property(GLOBAL PROPERTY RULE_LAUNCH_LINK ccache) # Less useful to do it for linking, see edit2
endif(CCACHE_FOUND)