A Note on CMake - 4 An example: ESESC

It may be bored to directly introduce the basic knowledge. Here I use an example from ESESC to show how to use CMake. ESECS is a fast multicore simulator using time-based sampling. We can download the source code from GitHub.

Now let us read CMakeLists.txt.

PROJECT(esesc)

set the name of this project as esesc

INCLUDE(“${esesc_SOURCE_DIR}/CMake.common”)

Load and run CMake code from ${esesc_SOURCE_DIR}/CMake.common. Actually, I don’t know what is ${esesc_SOURCE_DIR} but it should be the current folder or .. CMake.common sets the compiler and qemu options. Later, I will explain it.

SET(CMAKE_MODULE_PATH “${esesc_SOURCE_DIR}/conf/cmake-modules”)

set Set a normal, cache, or environment variable to a given value.
CMAKE_MODULE_PATH a search path for CMake modules to be loaded by include or find_package commands before checking the default modules that come with CMake. By default it is empty, it is intended to be set by the project.
Thus, the above command means set a search path with ${esesc_SOURCE_DIR}/conf/cmake-modules.

cmake_minimum_required(VERSION 2.7)

check cmake version

IF(ESESC_SYSTEM)
MESSAGE(” -DESESC_SYSTEM=1 Enable esesc/qemu full system simulation”)
ELSE(ESESC_SYSTEM)
MESSAGE(” -DESESC_SYSTEM=0 Enable esesc/qemu user mode simulation”)
ENDIF(ESESC_SYSTEM)

Now I still don’t know what is ESESC_SYSTEM, but we can use MESSAGE to guess the meaning.
MESSAGE Display a message to the user.

IF(ENABLE_LIVE)
MESSAGE(” -DESESC_LIVE=1 Enable esesc live sampling support”)
ELSE(ENABLE_LIVE)
MESSAGE(” -DESESC_LIVE=0 Disable esesc live compilation (default)”)
ENDIF(ENABLE_LIVE)

Similarly.

IF(ENABLE_LIVECRIU)
MESSAGE(” -DESESC_LIVECRIU=1 Enable CRIU checkpoints with live sampling support”)
ELSE(ENABLE_LIVECRIU)
MESSAGE(” -DESESC_LIVECRIU=0 Disable CRIU checkpoints with live compilation (default)”)
ENDIF(ENABLE_LIVECRIU)

Similarly.

MESSAGE(” -DCMAKE_HOST_MARCH=${CMAKE_HOST_MARCH} compilation”)

show message

Debug vs Release

IF(CMAKE_BUILD_TYPE MATCHES “Debug”)
MESSAGE(” -DCMAKE_BUILD_TYPE=Debug debug compilation options”)
ELSE(CMAKE_BUILD_TYPE MATCHES “Debug”)
MESSAGE(” -DCMAKE_BUILD_TYPE=Release release compilation options (default)”)
ENDIF(CMAKE_BUILD_TYPE MATCHES “Debug”)

ESESC supports two build types: debug and release. When run cmake, we may use cmake -DDEBUG=1 to activate debugging. Default setting is release.

FIND_PACKAGE(ZLIB)
FIND_PACKAGE(Threads)
FIND_PACKAGE(Curses)
FIND_PACKAGE(FLEX)
FIND_PACKAGE(BISON)
FIND_PACKAGE(X11)
FIND_PACKAGE(UUID)
FIND_PACKAGE(Pixman)
FIND_PACKAGE(Pango)

Find a series of external packages to help build.

if(COMMAND cmake_policy)
cmake_policy(SET CMP0003 NEW)
endif(COMMAND cmake_policy)

set cmake policy

IF(CMAKESYSTEMNAMEMATCHES“Linux”)INCLUDE(FindPkgConfig)PKGSEARCHMODULE(SDL2REQUIREDsdl2)FINDLIBRARY(RTLIBRARIESNAMESrt)ENDIF({CMAKE_SYSTEM_NAME} MATCHES “Linux”)

SDL package is only used for the linux platform.

FIND_LIBRARY(MLIB_LIBRARIES NAMES m)
FIND_LIBRARY(UTIL_LIBRARIES NAMES util)

Find and load libraries. I’m not sure what MLIB_LIBRARIES and UTIL_LIBRARIES mean.

ADD_SUBDIRECTORY(misc/libsuc)

Add a subdirectory misc/libsuc to the build. In this folder, there also exists a CMakeLists.txt.

The next codes are to try to set the external projects. I omit them.

include(ExternalProject)

ExternalProject_Add(…)

The ExternalProject_Add function creates a custom target to drive download, update/patch, configure, build, install and test steps of an external project

set_target_properties(regression PROPERTIES EXCLUDE_FROM_ALL TRUE)

Set how to build. If the EXCLUDE_FROM_ALL argument is provided then targets in the subdirectory will not be included in the ALL target of the parent directory by default, and will be excluded from IDE project files.

IF(CMAKE_BUILD_TYPE MATCHES “Debug”)
SET(QEMU_EXTRA –enable-debug –cc=${CMAKE_C_COMPILER})
ELSE(CMAKE_BUILD_TYPE MATCHES “Debug”)
SET(QEMU_EXTRA –cc=${CMAKE_C_COMPILER})
ENDIF(CMAKE_BUILD_TYPE MATCHES “Debug”)

IF(ESESC_SYSTEM)
SET(QEMU_TARGET –target-list=mips64el-softmmu)
ELSE(ESESC_SYSTEM)
IF(ESESC_N32)
SET(QEMU_TARGET –target-list=mipsn32el-linux-user)
ELSE(ESESC_N32)
SET(QEMU_TARGET –target-list=mips64el-linux-user)
ENDIF(ESESC_N32)
ENDIF(ESESC_SYSTEM)

ADD_SUBDIRECTORY(emul/libemulint)
ADD_SUBDIRECTORY(emul/libqemuint)
#
ADD_SUBDIRECTORY(pwth/libpeq)
ADD_SUBDIRECTORY(pwth/libmcpat)
ADD_SUBDIRECTORY(pwth/libsesctherm)
ADD_SUBDIRECTORY(pwth/libpwrmodel)

#

ADD_SUBDIRECTORY(simu/libcore)
ADD_SUBDIRECTORY(simu/libsampler)
ADD_SUBDIRECTORY(simu/libmem)
ADD_SUBDIRECTORY(simu/libnet)

#

ADD_SUBDIRECTORY(main)
ADD_SUBDIRECTORY(tests/gtest-1.7.0)
ADD_SUBDIRECTORY(tests)