c++ - 如何将变量传递给 cmake 脚本

问题描述

我正在尝试将变量传递给 cmake 脚本，但显然我没有正确执行它。我正在尝试按照教程构建一个计时项目。我正在关注的教程在这里：

https://api.projectchrono.org/tutorial_install_project.html

CMakeLists.txt 修改如下：

#--------------------------------------------------------------
# 
# Example of CMake configuration file to build an external 
# project depending on Chrono and on optional Chrono modules.
# 
# This minimal sample project can be used as a template for a
# user project.  Modify sections 1, 2, and 3 below as appropriate.
# 
#--------------------------------------------------------------
 

cmake_minimum_required(VERSION 2.8)

#--------------------------------------------------------------
# === 1 === 
# Modify the project name if you want: 
#--------------------------------------------------------------

project(my_project)

#--------------------------------------------------------------
# === 2 ===
# Find the Chrono package and any REQUIRED or OPTIONAL modules
# by invoking the find_package function in CONFIG mode:
find_package(Chrono
             COMPONENTS Irrlicht
             CONFIG)

# The following Chrono modules can be requested (their names
# are case insensitive): Cascade, Cosimulation, FEA, Irrlicht,
# Matlab, Parallel, Postprocess, Python, Vehicle.
# 
# Note that you will have to set the variable Chrono_DIR to 
# specify the location of the ChronoConfig.cmake script, if
# it is not in its default install location.
# Chrono_DIR can be either a Chrono build tree or a Chrono install tree.
# 
# The following variables are set and can be used further down:
# CHRONO_FOUND
#   set to true if Chrono and all required components were found
# CHRONO_C_FLAGS
# CHRONO_CXX_FLAGS
#   C and C++ compilation flags
# CHRONO_INCLUDE_DIRS
#   additional paths for included headers
# CHRONO_LIBRARIES
#   list of required libraries (with full path)
# CHRONO_LINKER_FLAGS
#   additional linker flags
# CHRONO_DLLS
#   list of all DLL dependencies (with full path)
# CHRONO_DATA_DIR
#   path to the Chrono data make_directory
# 
# In addition, for each requested component [COMPONENT], the
# following variable is set to true (ON) or false (OFF):
# CHRONO_[COMPONENT]_FOUND
# 
# In this example, we only request the Irrlicht module (required)
#--------------------------------------------------------------
#Chrono_DIR = "/home/richard/chrono_build/lib"

LIST(APPEND CMAKE_PREFIX_PATH "${CMAKE_INSTALL_PREFIX}/../Chrono/lib")
find_package(Chrono
             COMPONENTS Irrlicht
             CONFIG)

#--------------------------------------------------------------
# Return now if Chrono or a required component was not found.
#--------------------------------------------------------------

if (NOT Chrono_FOUND)
  message("Could not find Chrono or one of its required modules")
  return()
endif()

#--------------------------------------------------------------
# Enable creation of "application bundles" on MacOSX.
#--------------------------------------------------------------

# This is necessary for any Irrlicht-based project (like the example here).
# For OpenGL-based or non-graphics projects, this is optional and the block
# below can be removed (or else explcitly set CMAKE_MACOSX_BUNDLE to 'OFF').
#
# If creating application bundles, the build output will be named 'myexe.app'.
# Use the convenience script 'run_app.sh' available under 'contrib/appbundle-macosx/'
# to run:
#     start_demo.sh myexe.app

if(APPLE)
    set(CMAKE_MACOSX_BUNDLE ON)
endif()

#--------------------------------------------------------------
# Add path to Chrono headers and to headers of all dependencies
# of the requested modules.
#--------------------------------------------------------------

include_directories(${CHRONO_INCLUDE_DIRS})

#-----------------------------------------------------------------------------
# Fix for VS 2017 15.8 and newer to handle alignment specification with Eigen
#-----------------------------------------------------------------------------

if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
  if(MSVC AND ${MSVC_VERSION} GREATER_EQUAL 1915)
    add_definitions( "-D_ENABLE_EXTENDED_ALIGNED_STORAGE" )
  endif()
endif()

#--------------------------------------------------------------
# Tweaks to disable some warnings with MSVC
#--------------------------------------------------------------
if(MSVC)
    add_definitions("-D_CRT_SECURE_NO_DEPRECATE")  # avoids deprecation warnings
    add_definitions("-D_SCL_SECURE_NO_DEPRECATE")  # avoids deprecation warnings
    add_definitions( "-DNOMINMAX" )                # do not use MSVC's min/max macros
    set(EXTRA_COMPILE_FLAGS "/wd4275")             # disable warnings triggered by Irrlicht
else()
    set(EXTRA_COMPILE_FLAGS "")
endif()

#--------------------------------------------------------------
# === 3 ===
# Add the executable from your project and specify all C++ 
# files in your project. 
#--------------------------------------------------------------

add_executable(myexe my_example.cpp)

#--------------------------------------------------------------
# Set properties for your executable target
# 
# Note that here we define a macro CHRONO_DATA_DIR which will
# contain the path to the Chrono data directory, either in its
# source tree (if using a build version of Chrono), or in its
# install tree (if using an installed version of Chrono).
#--------------------------------------------------------------

set_target_properties(myexe PROPERTIES 
        COMPILE_FLAGS "${CHRONO_CXX_FLAGS} ${EXTRA_COMPILE_FLAGS}"
        COMPILE_DEFINITIONS "CHRONO_DATA_DIR=\"${CHRONO_DATA_DIR}\""
        LINK_FLAGS "${CHRONO_LINKER_FLAGS}")

#--------------------------------------------------------------
# Link to Chrono libraries and dependency libraries
#--------------------------------------------------------------

target_link_libraries(myexe ${CHRONO_LIBRARIES})

#--------------------------------------------------------------
# === 4 (OPTIONAL) ===
# 
# Optionally, add a custom command for copying all Chrono and
# dependency DLLs to the appropriate binary output folder.
# This function has effect only on Windows.
# 
# Note that you must first set EXECUTABLE_OUTPUT_PATH
# (this can simply be ${CMAKE_BINARY_DIR}, like in this example)
#--------------------------------------------------------------

set(EXECUTABLE_OUTPUT_PATH ${CMAKE_BINARY_DIR})
add_DLL_copy_command("${CHRONO_DLLS}")

我正在使用 Ubuntu 20.04，并尝试使用 cmake 设置构建。我正在使用的命令是：

cmake -S template_project/ -B build -Chrono_DIR:STRING=/home/richard/chrono_build/lib

我得到的错误是：

home/richard/chrono_build/lib
loading initial cache file hrono_DIR:STRING=/home/richard/chrono_build/lib
CMake Error: Error processing file: /home/richard/Chrono_workspace/hrono_DIR:STRING=/home/richard/chrono_build/lib
-- Could NOT find Chrono (missing: Chrono_DIR)
-- Could NOT find Chrono (missing: Chrono_DIR)
Could not find Chrono or one of its required modules
-- Configuring incomplete, errors occurred!
See also "/home/richard/Chrono_workspace/build/CMakeFiles/CMakeOutput.log".

显然，这不是正确设置“Chrono_Dir”的方法，因为我遇到了错误。使用 CMake 命令时如何传递该信息，还是需要将其添加到 cmakelists.txt 文件中？我知道这是一个新手问题，但我被困住了，需要一些帮助。我尝试关注这个 stackoverflow question，但我显然不明白发生了什么。

编辑：

我尝试下面的评论/答案是这样做的：

cmake -S template_project/ -B build -DChrono_DIR=/home/richard/chrono_build/lib

现在输出是：

-- Could NOT find Chrono (missing: Chrono_DIR)
-- Could NOT find Chrono (missing: Chrono_DIR)
Could not find Chrono or one of its required modules
-- Configuring done
-- Generating done
-- Build files have been written to: /home/richard/Chrono_workspace/build

标签： c++cmakeconfiguration

c++ - 如何将变量传递给 cmake 脚本

问题描述

解决方案

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