build.sh

#!/bin/sh
set -x
#相当于$(pwd)   
SOURCE_DIR=`pwd`
#不论是否存在BUILD_DIR环境变量，=右边的BUILD_DIR的值不会变，返回值即=左边的在本脚本起作用的BUILD_DIR值会被设置为../build
BUILD_DIR=${BUILD_DIR:-../build}
BUILD_TYPE=${BUILD_TYPE:-release}
INSTALL_DIR=${INSTALL_DIR:-../${BUILD_TYPE}-install-cpp11}
CXX=${CXX:-g++}
    
ln -sf $BUILD_DIR/$BUILD_TYPE-cpp11/compile_commands.json
    
mkdir -p $BUILD_DIR/$BUILD_TYPE-cpp11 \
&& cd $BUILD_DIR/$BUILD_TYPE-cpp11 \
&& cmake \
# 通过-D给cmakelists.txt传递宏定义
# CMAKE_INSTALL_PREFIX
# make install is invoked or INSTALL is built, this directory is prepended onto all install directories.
# This variable defaults to /usr/local on UNIX and c:/Program Files on Windows.
   -DCMAKE_BUILD_TYPE=$BUILD_TYPE \
   -DCMAKE_INSTALL_PREFIX=$INSTALL_DIR \
   -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
$SOURCE_DIR \
&& make $*
    
    # Use the following command to run all the unit tests
    # at the dir $BUILD_DIR/$BUILD_TYPE :
    # CTEST_OUTPUT_ON_FAILURE=TRUE make test

CMakeLists.txt

cmake_minimum_required(VERSION 2.6)
project(muduo C CXX)
enable_testing()
if(NOT CMAKE_BUILD_TYPE)
  set(CMAKE_BUILD_TYPE "Release")
endif()
# CMAKE_PROJECT_NAME this variable holds the name of the project as specified in the top level CMakeLists.txt
# only build examples if this is the main project
if(CMAKE_PROJECT_NAME STREQUAL "muduo")
# option(<variable> "<help_text>" [value])
# Provides an option for the user to select as ON or OFF. If no initial <value> is provided, OFF is used. If <variable> is already set as a normal
# variable then the command does nothing,在cmakelists.txt文件中使用
  option(MUDUO_BUILD_EXAMPLES "Build Muduo examples" ON)
endif()

set(CXX_FLAGS
 -g
 # -DVALGRIND
 -DCHECK_PTHREAD_RETURN_VALUE
 -D_FILE_OFFSET_BITS=64
 -Wall
 -Wextra
 -Werror
 -Wconversion
 -Wno-unused-parameter
 -Wold-style-cast
 -Woverloaded-virtual
 -Wpointer-arith
 -Wshadow
 -Wwrite-strings
 -march=native
 # -MMD
 -std=c++11
 -rdynamic
 )
if(CMAKE_BUILD_BITS EQUAL 32)
  list(APPEND CXX_FLAGS "-m32")
endif()
if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
  list(APPEND CXX_FLAGS "-Wno-null-dereference")
  list(APPEND CXX_FLAGS "-Wno-sign-conversion")
  list(APPEND CXX_FLAGS "-Wno-unused-local-typedef")
  list(APPEND CXX_FLAGS "-Wthread-safety")
  list(REMOVE_ITEM CXX_FLAGS "-rdynamic")
endif()
string(REPLACE ";" " " CMAKE_CXX_FLAGS "${CXX_FLAGS}")

set(CMAKE_CXX_FLAGS_DEBUG "-O0")
set(CMAKE_CXX_FLAGS_RELEASE "-O2 -DNDEBUG")
set(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
set(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR}/lib)

find_package(Boost REQUIRED)
find_package(Protobuf)
find_package(CURL)
find_package(ZLIB)
find_path(CARES_INCLUDE_DIR ares.h)
find_library(CARES_LIBRARY NAMES cares)
find_path(MHD_INCLUDE_DIR microhttpd.h)
find_library(MHD_LIBRARY NAMES microhttpd)
find_library(BOOSTTEST_LIBRARY NAMES boost_unit_test_framework)
find_library(BOOSTPO_LIBRARY NAMES boost_program_options)
find_library(BOOSTSYSTEM_LIBRARY NAMES boost_system)
find_path(TCMALLOC_INCLUDE_DIR gperftools/heap-profiler.h)
find_library(TCMALLOC_LIBRARY NAMES tcmalloc_and_profiler)
find_path(HIREDIS_INCLUDE_DIR hiredis/hiredis.h)
find_library(HIREDIS_LIBRARY NAMES hiredis)
find_path(GD_INCLUDE_DIR gd.h)
find_library(GD_LIBRARY NAMES gd)
find_program(THRIFT_COMPILER thrift)
find_path(THRIFT_INCLUDE_DIR thrift)
find_library(THRIFT_LIBRARY NAMES thrift)

if(CARES_INCLUDE_DIR AND CARES_LIBRARY)
  message(STATUS "found cares")
endif()
if(CURL_FOUND)
  message(STATUS "found curl")
endif()
if(PROTOBUF_FOUND)
  message(STATUS "found protobuf")
endif()
if(TCMALLOC_INCLUDE_DIR AND TCMALLOC_LIBRARY)
  message(STATUS "found tcmalloc")
endif()
if(ZLIB_FOUND)
  message(STATUS "found zlib")
endif()
if(HIREDIS_INCLUDE_DIR AND HIREDIS_LIBRARY)
  message(STATUS "found hiredis")
endif()
if(GD_INCLUDE_DIR AND GD_LIBRARY)
  message(STATUS "found gd")
endif()
if(THRIFT_COMPILER AND THRIFT_INCLUDE_DIR AND THRIFT_LIBRARY)
  message(STATUS "found thrift")
endif()

include_directories(${Boost_INCLUDE_DIRS})

include_directories(${PROJECT_SOURCE_DIR})

string(TOUPPER ${CMAKE_BUILD_TYPE} BUILD_TYPE)
message(STATUS "CXX_FLAGS = " ${CMAKE_CXX_FLAGS} " " ${CMAKE_CXX_FLAGS_${BUILD_TYPE}})

add_subdirectory(muduo/base)
add_subdirectory(muduo/net)

if(MUDUO_BUILD_EXAMPLES)
  add_subdirectory(contrib)
  add_subdirectory(examples)
else()
  if(CARES_INCLUDE_DIR AND CARES_LIBRARY)
    add_subdirectory(examples/cdns)
  endif()
endif()

add_definitions和add_definitions区别

The most straightforward solution should be using add_compile_options() if you are using version 2.8.12 or newer. For older versions you can "abuse" add_definitions(). While it is only meant for add -D flags, it also works with any other compiler flag. However, I think it is not meant to be used that way and could break in a future version.

add_compile_options(-std=c++0x) # CMake 2.8.12 or newer
or
add_definitions(-std=c++0x) # CMake 2.8.11 or older

Starting with CMake 3.3 you can also make this flag only apply to a specific language (e.g. only C or C++) using the strange generator expressions syntax:

add_compile_options(<COMPILE_LANGUAGE:CXX>:-std=c++14> <COMPILE_LANGUAGE:C>:-std=c99>)

However this will not work with the Visual studio generator, so make sure to only use this for Make/Ninja generators or use target_compile_options() to set it on a per-target scope.