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| author | Betsy McPhail <betsy.mcphail@kitware.com> | 2019-06-18 14:49:40 (GMT) |
|---|---|---|
| committer | Brad King <brad.king@kitware.com> | 2019-06-19 12:57:12 (GMT) |
| commit | eef3e020c21d2fdba19aab0daf1b99f8de0a16fe (patch) | |
| tree | 30c79204ed261551c611d6f1f159ef682c8b2b74 /Help/guide | |
| parent | 862cfc0e6c3f275db73281f3b9b989704251ab6a (diff) | |
| download | CMake-eef3e020c21d2fdba19aab0daf1b99f8de0a16fe.zip CMake-eef3e020c21d2fdba19aab0daf1b99f8de0a16fe.tar.gz CMake-eef3e020c21d2fdba19aab0daf1b99f8de0a16fe.tar.bz2 | |
Help: Populate tutorial guide text
Migrate tutorial text from individual `directions.txt` files to the main
tutorial document. Add some comments to source code to provide anchors
for inclusion.
Diffstat (limited to 'Help/guide')
44 files changed, 777 insertions, 939 deletions
diff --git a/Help/guide/tutorial/Complete/CMakeLists.txt b/Help/guide/tutorial/Complete/CMakeLists.txt index 1c97545..e84f932 100644 --- a/Help/guide/tutorial/Complete/CMakeLists.txt +++ b/Help/guide/tutorial/Complete/CMakeLists.txt @@ -1,20 +1,20 @@ cmake_minimum_required(VERSION 3.3) project(Tutorial) +set(CMAKE_CXX_STANDARD 14) + +# set the version number +set(Tutorial_VERSION_MAJOR 1) +set(Tutorial_VERSION_MINOR 0) + # control where the static and shared libraries are built so that on windows # we don't need to tinker with the path to run the executable set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}") set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}") set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}") -set(CMAKE_CXX_STANDARD 14) - option(BUILD_SHARED_LIBS "Build using shared libraries" ON) -# the version number. -set(Tutorial_VERSION_MAJOR 1) -set(Tutorial_VERSION_MINOR 0) - if(APPLE) set(CMAKE_INSTALL_RPATH "@executable_path/../lib") elseif(UNIX) diff --git a/Help/guide/tutorial/Complete/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Complete/MathFunctions/CMakeLists.txt index 161ad64..63c0f5f 100644 --- a/Help/guide/tutorial/Complete/MathFunctions/CMakeLists.txt +++ b/Help/guide/tutorial/Complete/MathFunctions/CMakeLists.txt @@ -1,4 +1,3 @@ - # add the library that runs add_library(MathFunctions MathFunctions.cxx) @@ -62,6 +61,7 @@ target_compile_definitions(MathFunctions PRIVATE "EXPORTING_MYMATH") set_property(TARGET MathFunctions PROPERTY VERSION "1.0.0") set_property(TARGET MathFunctions PROPERTY SOVERSION "1") +# install rules install(TARGETS MathFunctions DESTINATION lib EXPORT MathFunctionsTargets) diff --git a/Help/guide/tutorial/Consumer/directions.txt b/Help/guide/tutorial/Consumer/directions.txt deleted file mode 100644 index 6a70aab..0000000 --- a/Help/guide/tutorial/Consumer/directions.txt +++ /dev/null @@ -1,6 +0,0 @@ -# Import a CMake Project# - -This examples shows how a project can find other CMake packages that -generated Config.cmake files. - -It also shows how to state a projects external dependencies when generating a Config.cmake. diff --git a/Help/guide/tutorial/MultiPackage/directions.txt b/Help/guide/tutorial/MultiPackage/directions.txt deleted file mode 100644 index c3102bb..0000000 --- a/Help/guide/tutorial/MultiPackage/directions.txt +++ /dev/null @@ -1,34 +0,0 @@ -# Packaging Debug and Release # - -By default CMake is model is that a build directory only contains a single -configuration, be it Debug, Release, MinSizeRel, or RelWithDebInfo. - -But it is possible to setup CPack to bundle multiple build directories at the same -time to build a package that contains multiple configurations of the same project. - -First we need to ahead and construct a directory called 'multi_config' this -will contain all the builds that we want to package together. - -Second create a 'debug' and 'release' directory underneath 'multi_config'. At -the end you should have a layout that looks like: - -─ multi_config - ├── debug - └── release - -Now we need to setup debug and release builds, which would roughly entail -the following: - - cd debug - cmake -DCMAKE_BUILD_TYPE=Debug ../../MultiPackage/ - cmake --build . - cd ../release - cmake -DCMAKE_BUILD_TYPE=Release ../../MultiPackage/ - cmake --build . - cd .. - - -Now that both the debug and release builds are complete we can now use -the custom MultiCPackConfig to package both builds into a single release. - - cpack --config ../../MultiPackage/MultiCPackConfig.cmake diff --git a/Help/guide/tutorial/Readme.txt b/Help/guide/tutorial/Readme.txt deleted file mode 100644 index 74eb01a..0000000 --- a/Help/guide/tutorial/Readme.txt +++ /dev/null @@ -1,16 +0,0 @@ - -Step 0: A Starting Point -Step 1: Configure a File and C++11 Controls -Step 2: Adding a Library -Step 3: Usage Requirements for Library -Step 4: Installing and Testing -Step 5: System Introspection -Step 6: Custom Command and Generated File -Step 7: Building an Installer -Step 8: CDash submission -Step 9: Mixing Static and Shared -Step 10: Generator Expressions -Step 11: Adding Export Configuration -Complete: End result of Step 11 -Consumer: Example of Import Packages -MultiPackage: How to package Debug and Release versions diff --git a/Help/guide/tutorial/Step1/directions.txt b/Help/guide/tutorial/Step1/directions.txt deleted file mode 100644 index 827d775..0000000 --- a/Help/guide/tutorial/Step1/directions.txt +++ /dev/null @@ -1,95 +0,0 @@ -# Adding a Version Number and Configured Header File # - -The first feature we will add is to provide our executable and project with a -version number. While we could do this exclusively in the source code, using -CMakeLists provides more flexibility. - -To add a version number we modify the CMakeLists file as follows: - - cmake_minimum_required(VERSION 3.3) - project(Tutorial) - - # the version number. - set(Tutorial_VERSION_MAJOR 1) - set(Tutorial_VERSION_MINOR 0) - - # configure a header file to pass some of the CMake settings - # to the source code - configure_file( - "${PROJECT_SOURCE_DIR}/TutorialConfig.h.in" - "${PROJECT_BINARY_DIR}/TutorialConfig.h" - ) - - # add the executable - add_executable(Tutorial tutorial.cxx) - - # add the binary tree to the search path for include files - # so that we will find TutorialConfig.h - target_include_directories(Tutorial PUBLIC - "${PROJECT_BINARY_DIR}" - ) - - -We then create a TutorialConfig.h.in file in the source tree with the -following contents: - - // the configured options and settings for Tutorial - #define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@ - #define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@ - -When CMake configures this header file the values for @Tutorial_VERSION_MAJOR@ -and @Tutorial_VERSION_MINOR@ will be replaced by the values from the CMakeLists -file. Next we modify tutorial.cxx to include the configured header file and to -make use of the version numbers. The resulting source code is listed below. - - // A simple program that computes the square root of a number - #include <cmath> - #include <iostream> - #include <string> - #include <sstream> - - #include "TutorialConfig.h" - - int main (int argc, char *argv[]) - { - if (argc < 2) { - std::cout << argv[0] << " Version " - << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR - << std::endl; - std::cout << "Usage: " << argv[0] << " number" << std::endl; - return 1; - } - - double inputValue = atof(argv[1]); - - double outputValue = sqrt(inputValue); - std::cout << "The square root of " - << inputValue << " is " << outputValue << std::endl; - return 0; - } - -# Adding C++11 support # - -Let's add some C++11 features to our project. We will need to explicitly state -in the CMake code that it should use the correct flags. The easiest way to -enable C++11 support for CMake is by using the CMAKE_CXX_STANDARD -and CMAKE_CXX_STANDARD_REQUIRED variables. - -First, replace `atof` with `std::stod` in tutorial.cxx. - -Then, add the CMAKE_CXX_STANDARD and CMAKE_CXX_STANDARD_REQUIRED variables to -the CMakeLists file. The STANADARD value should be set to 11, and REQUIRED -should be set to True. - - -# Build and Test # - -Run cmake or cmake-gui to configure the project and then build it with your -chosen build tool - -cd to the directory where Tutorial was built (likely the make directory or -a Debug or Release build configuration subdirectory) and run these commands: - - Tutorial 4294967296 - Tutorial 10 - Tutorial diff --git a/Help/guide/tutorial/Step10/CMakeLists.txt b/Help/guide/tutorial/Step10/CMakeLists.txt index 79aadd5..5819272 100644 --- a/Help/guide/tutorial/Step10/CMakeLists.txt +++ b/Help/guide/tutorial/Step10/CMakeLists.txt @@ -1,20 +1,20 @@ cmake_minimum_required(VERSION 3.3) project(Tutorial) +set(CMAKE_CXX_STANDARD 14) + +# Set the version number +set(Tutorial_VERSION_MAJOR 1) +set(Tutorial_VERSION_MINOR 0) + # control where the static and shared libraries are built so that on windows # we don't need to tinker with the path to run the executable set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}") set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}") set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}") -set(CMAKE_CXX_STANDARD 14) - option(BUILD_SHARED_LIBS "Build using shared libraries" ON) -# the version number. -set(Tutorial_VERSION_MAJOR 1) -set(Tutorial_VERSION_MINOR 0) - # configure a header file to pass the version number only configure_file( "${PROJECT_SOURCE_DIR}/TutorialConfig.h.in" diff --git a/Help/guide/tutorial/Step10/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step10/MathFunctions/CMakeLists.txt index 7a23505..aafd090 100644 --- a/Help/guide/tutorial/Step10/MathFunctions/CMakeLists.txt +++ b/Help/guide/tutorial/Step10/MathFunctions/CMakeLists.txt @@ -1,4 +1,3 @@ - # add the library that runs add_library(MathFunctions MathFunctions.cxx) @@ -57,5 +56,6 @@ endif() # building on windows target_compile_definitions(MathFunctions PRIVATE "EXPORTING_MYMATH") +# install rules install(TARGETS MathFunctions DESTINATION lib) install(FILES MathFunctions.h DESTINATION include) diff --git a/Help/guide/tutorial/Step10/directions.txt b/Help/guide/tutorial/Step10/directions.txt deleted file mode 100644 index 5317b54..0000000 --- a/Help/guide/tutorial/Step10/directions.txt +++ /dev/null @@ -1,38 +0,0 @@ -# Adding Generator Expressions # - -Generator expressions are evaluated during build system generation to produce -information specific to each build configuration. - -Generator expressions are allowed in the context of many target properties, such -as LINK_LIBRARIES, INCLUDE_DIRECTORIES, COMPILE_DEFINITIONS and others. They may -also be used when using commands to populate those properties, such as -target_link_libraries(), target_include_directories(), -target_compile_definitions() and others. - -Generator expressions may to used to enable conditional linking, conditional -definitions used when compiling, and conditional include directories and more. -The conditions may be based on the build configuration, target properties, -platform information or any other queryable information. - -There are different types of generator expressions including Logical, -Informational, and Output expressions. - -Logical expressions are used to create conditional output. The basic expressions -are the 0 and 1 expressions. A "$<0:...>" results in the empty string, and -"$<1:...>" results in the content of "...". They can also be nested. -For example: - - if(HAVE_LOG AND HAVE_EXP) - target_compile_definitions(SqrtLibrary - PRIVATE "HAVE_LOG" "HAVE_EXP") - endif() - -Can be rewritten with generator expressions: - - target_compile_definitions(SqrtLibrary PRIVATE - "$<$<BOOL:${HAVE_LOG}>:HAVE_LOG>" - "$<$<BOOL:${HAVE_EXP}>:HAVE_EXP>" - ) - -Note that "${HAVE_LOG}" is evaluated at CMake configure time while -"$<$<BOOL:${HAVE_LOG}>:HAVE_LOG>" is evaluated at build system generation time. diff --git a/Help/guide/tutorial/Step10/tutorial.cxx b/Help/guide/tutorial/Step10/tutorial.cxx index 4451cbd..42eaab9 100644 --- a/Help/guide/tutorial/Step10/tutorial.cxx +++ b/Help/guide/tutorial/Step10/tutorial.cxx @@ -9,6 +9,7 @@ int main(int argc, char* argv[]) { if (argc < 2) { + // report version std::cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR << std::endl; std::cout << "Usage: " << argv[0] << " number" << std::endl; diff --git a/Help/guide/tutorial/Step11/CMakeLists.txt b/Help/guide/tutorial/Step11/CMakeLists.txt index 79aadd5..2e5cb15 100644 --- a/Help/guide/tutorial/Step11/CMakeLists.txt +++ b/Help/guide/tutorial/Step11/CMakeLists.txt @@ -1,20 +1,20 @@ cmake_minimum_required(VERSION 3.3) project(Tutorial) +set(CMAKE_CXX_STANDARD 14) + +# set the version number +set(Tutorial_VERSION_MAJOR 1) +set(Tutorial_VERSION_MINOR 0) + # control where the static and shared libraries are built so that on windows # we don't need to tinker with the path to run the executable set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}") set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}") set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}") -set(CMAKE_CXX_STANDARD 14) - option(BUILD_SHARED_LIBS "Build using shared libraries" ON) -# the version number. -set(Tutorial_VERSION_MAJOR 1) -set(Tutorial_VERSION_MINOR 0) - # configure a header file to pass the version number only configure_file( "${PROJECT_SOURCE_DIR}/TutorialConfig.h.in" diff --git a/Help/guide/tutorial/Step11/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step11/MathFunctions/CMakeLists.txt index 760d6a5..ea42770 100644 --- a/Help/guide/tutorial/Step11/MathFunctions/CMakeLists.txt +++ b/Help/guide/tutorial/Step11/MathFunctions/CMakeLists.txt @@ -1,4 +1,3 @@ - # add the library that runs add_library(MathFunctions MathFunctions.cxx) @@ -56,5 +55,6 @@ target_compile_definitions(MathFunctions PRIVATE "$<$<BOOL:${USE_MYMATH}>:USE_MY #building on windows target_compile_definitions(MathFunctions PRIVATE "EXPORTING_MYMATH") +# install rules install(TARGETS MathFunctions DESTINATION lib) install(FILES MathFunctions.h DESTINATION include) diff --git a/Help/guide/tutorial/Step11/directions.txt b/Help/guide/tutorial/Step11/directions.txt deleted file mode 100644 index ebb5def..0000000 --- a/Help/guide/tutorial/Step11/directions.txt +++ /dev/null @@ -1,104 +0,0 @@ -# Adding Export Configuration # - -During Step 4 of the tutorial we added the ability for CMake to install the -library and headers of the project. During Step 7 we added the ability -to package up this information so it could be distributed to other people. - -The next step is to add the necessary information so that other CMake projects -can use our project, be it from a build directory, a local install or when -packaged. - -The first step is to update our install(TARGETS) commands to not only specify -a DESTINATION but also an EXPORT. The EXPORT keyword generates and installs a -CMake file containing code to import all targets listed in the install command -from the installation tree. So let's go ahead and explicitly EXPORT the -MathFunctions library by updating the install command in -MathFunctions/CMakeLists.txt to look like: - - install(TARGETS MathFunctions DESTINATION lib EXPORT MathFunctionsTargets) - -Now that we have MathFunctions being exported, we also need to explicitly install -the generated MathFunctionsTargets.cmake file. This is done by adding -the following to the bottom of the top-level CMakeLists.txt: - - # install the configuration targets - install(EXPORT MathFunctionsTargets - FILE MathFunctionsTargets.cmake - DESTINATION lib/cmake/MathFunctions - ) - -At this point you should try and run CMake. If everything is setup properly -you will see that CMake will generate an error that looks like: - - Target "MathFunctions" INTERFACE_INCLUDE_DIRECTORIES property contains - path: - - "/Users/robert/Documents/CMakeClass/Tutorial/Step11/MathFunctions" - - which is prefixed in the source directory. - -What CMake is trying to say is that during generating the export information -it will export a path that is intrinsically tied to the current machine and -will not be valid on other machines. The solution to this is to update the -MathFunctions target_include_directories to understand that it needs different -INTERFACE locations when being used from within the build directory and from an -install / package. This means converting the target_include_directories -call for MathFunctions to look like: - - target_include_directories(MathFunctions - INTERFACE - $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}> - $<INSTALL_INTERFACE:include> - ) - -Once this has been updated, we can re-run CMake and see verify that it doesn't -warn anymore. - -At this point, we have CMake properly packaging the target information that is -required but we will still need to generate a MathFunctionsConfig.cmake, so -that the CMake find_package command can find our project. So let's go ahead and -add a new file to the top-level of the project called Config.cmake.in with the -following contents: - - @PACKAGE_INIT@ - - include ( "${CMAKE_CURRENT_LIST_DIR}/MathFunctionsTargets.cmake" ) - -Then, to properly configure and install that file, add the following to the -bottom of the top-level CMakeLists: - - include(CMakePackageConfigHelpers) - # generate the config file that is includes the exports - configure_package_config_file(${CMAKE_CURRENT_SOURCE_DIR}/Config.cmake.in - "${CMAKE_CURRENT_BINARY_DIR}/MathFunctionsConfig.cmake" - INSTALL_DESTINATION "lib/cmake/example" - NO_SET_AND_CHECK_MACRO - NO_CHECK_REQUIRED_COMPONENTS_MACRO - ) - # generate the version file for the config file - write_basic_package_version_file( - "${CMAKE_CURRENT_BINARY_DIR}/MathFunctionsConfigVersion.cmake" - VERSION "${Tutorial_VERSION_MAJOR}.${Tutorial_VERSION_MINOR}" - COMPATIBILITY AnyNewerVersion - ) - - # install the configuration file - install(FILES - ${CMAKE_CURRENT_BINARY_DIR}/MathFunctionsConfig.cmake - DESTINATION lib/cmake/MathFunctions - ) - -At this point, we have generated a relocatable CMake Configuration for our project -that can be used after the project has been installed or packaged. If we want -our project to also be used from a build directory we only have to add -the following to the bottom of the top level CMakeLists: - - # generate the export targets for the build tree - # needs to be after the install(TARGETS ) command - export(EXPORT MathFunctionsTargets - FILE "${CMAKE_CURRENT_BINARY_DIR}/MathFunctionsTargets.cmake" - ) - -With this export call we now generate a Targets.cmake, allowing the configured -MathFunctionsConfig.cmake in the build directory to be used by other projects, -without needing it to be installed. diff --git a/Help/guide/tutorial/Step11/tutorial.cxx b/Help/guide/tutorial/Step11/tutorial.cxx index 38d4a79..6acafd2 100644 --- a/Help/guide/tutorial/Step11/tutorial.cxx +++ b/Help/guide/tutorial/Step11/tutorial.cxx @@ -9,6 +9,7 @@ int main(int argc, char* argv[]) { if (argc < 2) { + // report version std::cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR << std::endl; std::cout << "Usage: " << argv[0] << " number" << std::endl; diff --git a/Help/guide/tutorial/Step2/CMakeLists.txt b/Help/guide/tutorial/Step2/CMakeLists.txt index 8e50e7c..1f43b2b 100644 --- a/Help/guide/tutorial/Step2/CMakeLists.txt +++ b/Help/guide/tutorial/Step2/CMakeLists.txt @@ -2,7 +2,8 @@ cmake_minimum_required(VERSION 3.3) project(Tutorial) set(CMAKE_CXX_STANDARD 14) -# the version number. + +# set the version number set(Tutorial_VERSION_MAJOR 1) set(Tutorial_VERSION_MINOR 0) diff --git a/Help/guide/tutorial/Step2/directions.txt b/Help/guide/tutorial/Step2/directions.txt deleted file mode 100644 index 48de7a2..0000000 --- a/Help/guide/tutorial/Step2/directions.txt +++ /dev/null @@ -1,101 +0,0 @@ -# Adding a Library # - -Now we will add a library to our project. This library will contain our own -implementation for computing the square root of a number. The executable can -then use this library instead of the standard square root function provided by -the compiler. - -For this tutorial we will put the library into a subdirectory -called MathFunctions. It will have the following one line CMakeLists file: - - add_library(MathFunctions mysqrt.cxx) - -The source file mysqrt.cxx has one function called mysqrt that provides similar -functionality to the compiler’s sqrt function. To make use of the new library -we add an add_subdirectory call in the top-level CMakeLists file so that the -library will get built. We add the new library to the executable, and add the -MathFunctions as an include directory so that mqsqrt.h header file can be -found. The last few lines of the top-level CMakeLists file now look like: - - - add_subdirectory(MathFunctions) - - #add the executable - add_executable(Tutorial tutorial.cxx) - - target_link_libraries(Tutorial ${EXTRA_LIBS}) - - -Now let us make the MathFunctions library optional. While for the tutorial -there really isn’t any need to do so, but with larger projects this is a common -occurrence. The first step is to add an option to the top-level CMakeLists file. - - option (USE_MYMATH - "Use tutorial provided math implementation" ON) - -This will show up in CMake GUI and ccmake with a default value of ON that can -be changed by the user. This setting will be stored so that the user does not -need to set the value each time they run CMake on this build directory. - -The next change is to make building and linking the MathFunctions library -conditional. To do this we change the top-level CMakeLists file to look like -the following: - - cmake_minimum_required(VERSION 3.3) - project(Tutorial) - - set(CMAKE_CXX_STANDARD 14) - - # the version number. - set(Tutorial_VERSION_MAJOR 1) - set(Tutorial_VERSION_MINOR 0) - - # configure a header file to pass some of the CMake settings - # to the source code - configure_file( - "${PROJECT_SOURCE_DIR}/TutorialConfig.h.in" - "${PROJECT_BINARY_DIR}/TutorialConfig.h" - ) - - # should we use our own math functions - option(USE_MYMATH "Use tutorial provided math implementation" ON) - - # add the MathFunctions library? - if(USE_MYMATH) - add_subdirectory(MathFunctions) - list(APPEND EXTRA_LIBS MathFunctions) - list(APPEND EXTRA_INCLUDES "${PROJECT_SOURCE_DIR}/MathFunctions") - endif(USE_MYMATH) - - # add the executable - add_executable(Tutorial tutorial.cxx) - - target_link_libraries(Tutorial ${EXTRA_LIBS}) - - # add the binary tree to the search path for include files - # so that we will find TutorialConfig.h - target_include_directories(Tutorial PUBLIC - "${PROJECT_BINARY_DIR}" - ${EXTRA_INCLUDES} - ) - -Note the use of the variables EXTRA_LIBS, and EXTRA_INCLUDES to collect -up any optional libraries to later be linked into the executable. This is a -classic approach when dealing with many optional components, we will cover the -modern approach in the next step. For now the corresponding changes to the -source code are fairly straightforward and leave us with: - - #ifdef USE_MYMATH - double outputValue = mysqrt(inputValue); - #else - double outputValue = sqrt(inputValue); - #endif - -Since the source code now requires USE_MYMATH we can add it to the -TutorialConfig.h.in. Simply add the following line: - #cmakedefine USE_MYMATH - -Run cmake or cmake-gui to configure the project and then build it with your -chosen build tool and then run the built Tutorial executable. - -Which function gives better results, Step1’s sqrt or Step2’s mysqrt? diff --git a/Help/guide/tutorial/Step2/tutorial.cxx b/Help/guide/tutorial/Step2/tutorial.cxx index 5ba34e8..f2ab446 100644 --- a/Help/guide/tutorial/Step2/tutorial.cxx +++ b/Help/guide/tutorial/Step2/tutorial.cxx @@ -8,6 +8,7 @@ int main(int argc, char* argv[]) { if (argc < 2) { + // report version std::cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR << std::endl; std::cout << "Usage: " << argv[0] << " number" << std::endl; diff --git a/Help/guide/tutorial/Step3/CMakeLists.txt b/Help/guide/tutorial/Step3/CMakeLists.txt index baa0a44..966c38a 100644 --- a/Help/guide/tutorial/Step3/CMakeLists.txt +++ b/Help/guide/tutorial/Step3/CMakeLists.txt @@ -6,7 +6,7 @@ set(CMAKE_CXX_STANDARD 14) # should we use our own math functions option(USE_MYMATH "Use tutorial provided math implementation" ON) -# the version number. +# set the version number set(Tutorial_VERSION_MAJOR 1) set(Tutorial_VERSION_MINOR 0) diff --git a/Help/guide/tutorial/Step3/directions.txt b/Help/guide/tutorial/Step3/directions.txt deleted file mode 100644 index 54d0318..0000000 --- a/Help/guide/tutorial/Step3/directions.txt +++ /dev/null @@ -1,26 +0,0 @@ -# Adding Usage Requirements for Library # - -Usage requirements allow for far better control over a library / executable's -link and include line. While also giving more control over the transitive -property of targets inside CMake. The primary commands that leverage usage -requirements are: - - - target_compile_definitions - - target_compile_options - - target_include_directories - - target_link_libraries - -First up is MathFunctions. We first state that anybody linking to MathFunctions -needs to include the current source directory, while MathFunctions itself -doesn't. So this can become an INTERFACE usage requirement. - -Remember INTERFACE means things that consumers require but the producer doesn't. - - target_include_directories(MathFunctions - INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}) - -Now that we've specified usage requirements for MathFunctions we can safely remove -our uses of the EXTRA_INCLUDES variable. - -Run cmake or cmake-gui to configure the project and then build it with your -chosen build tool. diff --git a/Help/guide/tutorial/Step3/tutorial.cxx b/Help/guide/tutorial/Step3/tutorial.cxx index c2b89df..8156a9c 100644 --- a/Help/guide/tutorial/Step3/tutorial.cxx +++ b/Help/guide/tutorial/Step3/tutorial.cxx @@ -5,6 +5,7 @@ #include "TutorialConfig.h" +// should we include the MathFunctions header? #ifdef USE_MYMATH # include "MathFunctions.h" #endif @@ -12,6 +13,7 @@ int main(int argc, char* argv[]) { if (argc < 2) { + // report version std::cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR << std::endl; std::cout << "Usage: " << argv[0] << " number" << std::endl; @@ -20,6 +22,7 @@ int main(int argc, char* argv[]) double inputValue = std::stod(argv[1]); + // which square root function should we use? #ifdef USE_MYMATH double outputValue = mysqrt(inputValue); #else diff --git a/Help/guide/tutorial/Step4/CMakeLists.txt b/Help/guide/tutorial/Step4/CMakeLists.txt index 9ce60b9..a157bda 100644 --- a/Help/guide/tutorial/Step4/CMakeLists.txt +++ b/Help/guide/tutorial/Step4/CMakeLists.txt @@ -6,7 +6,7 @@ set(CMAKE_CXX_STANDARD 14) # should we use our own math functions option(USE_MYMATH "Use tutorial provided math implementation" ON) -# the version number. +# set the version number set(Tutorial_VERSION_MAJOR 1) set(Tutorial_VERSION_MINOR 0) diff --git a/Help/guide/tutorial/Step4/directions.txt b/Help/guide/tutorial/Step4/directions.txt deleted file mode 100644 index 91e4043..0000000 --- a/Help/guide/tutorial/Step4/directions.txt +++ /dev/null @@ -1,72 +0,0 @@ -# Installing and Testing # - -Now we can start adding testing support and install rules to our project. - -The install rules are fairly simple; for MathFunctions we install the library -and header file, for the application we install the executable and configured -header. - -So to MathFunctions/CMakeLists.txt we add: - - install (TARGETS MathFunctions DESTINATION bin) - install (FILES MathFunctions.h DESTINATION include) - -And the to top-level CMakeLists.txt we add: - - install(TARGETS Tutorial DESTINATION bin) - install(FILES "${PROJECT_BINARY_DIR}/TutorialConfig.h" - DESTINATION include - ) - -That is all that is needed to create a basic local install of the tutorial. - -Run cmake or cmake-gui to configure the project and then build it with your -chosen build tool. Then build the “install” target by typing 'make install' -from the command line or build the INSTALL target from an IDE. This will -install the appropriate header files, libraries, and executables. - -Verify that the installed Tutorial runs. Note: The CMake variable -CMAKE_INSTALL_PREFIX is used to determine the root of where the files will -be installed. - -Next let's test our application. Adding testing is an easy process. At the -end of the top-level CMakeLists file we can add a number of basic tests to -verify that the application is working correctly. - - # enable testing - enable_testing() - - # does the application run - add_test(NAME Runs COMMAND Tutorial 25) - - # does the usage message work? - add_test(NAME Usage COMMAND Tutorial) - set_tests_properties(Usage - PROPERTIES PASS_REGULAR_EXPRESSION "Usage:.*number" - ) - - # define a function to simplify adding tests - function(do_test target arg result) - add_test(NAME Comp${arg} COMMAND ${target} ${arg}) - set_tests_properties(Comp${arg} - PROPERTIES PASS_REGULAR_EXPRESSION ${result} - ) - endfunction(do_test) - - # do a bunch of result based tests - do_test(Tutorial 25 "25 is 5") - do_test(Tutorial -25 "-25 is [-nan|nan|0]") - do_test(Tutorial 0.0001 "0.0001 is 0.01") - -The first test simply verifies that the application runs, does not segfault or -otherwise crash, and has a zero return value. This is the basic form of a CTest -test. - -The Usage test uses a regular expression to verify that the usage message -is printed when an incorrect number of arguments are provided. - -Lastly, we have a function called do_test that simplifies running the -application and verifying that the computed square root is correct for given -input. - -To run tests, cd to the binary directory and run “ctest -N” and “ctest -VV”. diff --git a/Help/guide/tutorial/Step4/tutorial.cxx b/Help/guide/tutorial/Step4/tutorial.cxx index c2b89df..8156a9c 100644 --- a/Help/guide/tutorial/Step4/tutorial.cxx +++ b/Help/guide/tutorial/Step4/tutorial.cxx @@ -5,6 +5,7 @@ #include "TutorialConfig.h" +// should we include the MathFunctions header? #ifdef USE_MYMATH # include "MathFunctions.h" #endif @@ -12,6 +13,7 @@ int main(int argc, char* argv[]) { if (argc < 2) { + // report version std::cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR << std::endl; std::cout << "Usage: " << argv[0] << " number" << std::endl; @@ -20,6 +22,7 @@ int main(int argc, char* argv[]) double inputValue = std::stod(argv[1]); + // which square root function should we use? #ifdef USE_MYMATH double outputValue = mysqrt(inputValue); #else diff --git a/Help/guide/tutorial/Step5/CMakeLists.txt b/Help/guide/tutorial/Step5/CMakeLists.txt index 828b9fc..76b9179 100644 --- a/Help/guide/tutorial/Step5/CMakeLists.txt +++ b/Help/guide/tutorial/Step5/CMakeLists.txt @@ -6,7 +6,7 @@ set(CMAKE_CXX_STANDARD 14) # should we use our own math functions option(USE_MYMATH "Use tutorial provided math implementation" ON) -# the version number. +# set the version number set(Tutorial_VERSION_MAJOR 1) set(Tutorial_VERSION_MINOR 0) diff --git a/Help/guide/tutorial/Step5/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step5/MathFunctions/CMakeLists.txt index 11cf412..b12f27d 100644 --- a/Help/guide/tutorial/Step5/MathFunctions/CMakeLists.txt +++ b/Help/guide/tutorial/Step5/MathFunctions/CMakeLists.txt @@ -6,5 +6,6 @@ target_include_directories(MathFunctions INTERFACE ${CMAKE_CURRENT_SOURCE_DIR} ) +# install rules install(TARGETS MathFunctions DESTINATION lib) install(FILES MathFunctions.h DESTINATION include) diff --git a/Help/guide/tutorial/Step5/directions.txt b/Help/guide/tutorial/Step5/directions.txt deleted file mode 100644 index e6f5197..0000000 --- a/Help/guide/tutorial/Step5/directions.txt +++ /dev/null @@ -1,69 +0,0 @@ -# Adding System Introspection # - -Let us consider adding some code to our project that depends on features the -target platform may not have. For this example, we will add some code that -depends on whether or not the target platform has the log and exp functions. Of -course almost every platform has these functions but for this tutorial assume -that they are not common. - -If the platform has log and exp then we will use them to compute the square -root in the mysqrt function. We first test for the availability of these -functions using the CheckSymbolExists.cmake macro in the top-level CMakeLists -file as follows: - - # does this system provide the log and exp functions? - include(CheckSymbolExists) - set(CMAKE_REQUIRED_LIBRARIES "m") - check_symbol_exists(log "math.h" HAVE_LOG) - check_symbol_exists(exp "math.h" HAVE_EXP) - -Now let's add these defines to TutorialConfig.h.in so that we can use them -from mysqrt.cxx: - - // does the platform provide exp and log functions? - #cmakedefine HAVE_LOG - #cmakedefine HAVE_EXP - -Modify mysqrt.cxx to include math.h. Next, in the mysqrt function we can -provide an alternate implementation based on log and exp if they are available -on the system using the following code: - - // if we have both log and exp then use them - #if defined(HAVE_LOG) && defined (HAVE_EXP) - double result = exp(log(x)*0.5); - std::cout << "Computing sqrt of " << x << " to be " << result << " using log" << std::endl; - #else - ... - -Run cmake or cmake-gui to configure the project and then build it with your -chosen build tool. - -You will notice that even though HAVE_LOG and HAVE_EXP are both defined mysqrt -isn't using them. We should realize quickly that we have forgotten to include -TutorialConfig.h in mysqrt.cxx. We will also need to update -MathFunctions/CMakeLists.txt with where it is located. - -So let's go ahead and update MathFunctions/CMakeLists.txt to look like: - - add_library(MathFunctions mysqrt.cxx) - - target_include_directories(MathFunctions - INTERFACE ${CMAKE_CURRENT_SOURCE_DIR} - PRIVATE ${Tutorial_BINARY_DIR} - ) - - install(TARGETS MathFunctions DESTINATION lib) - install(FILES MathFunctions.h DESTINATION include) - -Now all we need to do is include TutorialConfig.h in mysqrt.cxx - -At this point you should go ahead and build the project again. - -Run the built Tutorial executable. Which function gives better results now, -Step1’s sqrt or Step5’s mysqrt? - -Exercise: Why is it important that we configure TutorialConfig.h.in after the -checks for HAVE_LOG and HAVE_EXP? What would happen if we inverted the two? - -Exercise: Is there a better place for us to save the HAVE_LOG and HAVE_EXP -values other than in TutorialConfig.h? diff --git a/Help/guide/tutorial/Step5/tutorial.cxx b/Help/guide/tutorial/Step5/tutorial.cxx index c2b89df..8156a9c 100644 --- a/Help/guide/tutorial/Step5/tutorial.cxx +++ b/Help/guide/tutorial/Step5/tutorial.cxx @@ -5,6 +5,7 @@ #include "TutorialConfig.h" +// should we include the MathFunctions header? #ifdef USE_MYMATH # include "MathFunctions.h" #endif @@ -12,6 +13,7 @@ int main(int argc, char* argv[]) { if (argc < 2) { + // report version std::cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR << std::endl; std::cout << "Usage: " << argv[0] << " number" << std::endl; @@ -20,6 +22,7 @@ int main(int argc, char* argv[]) double inputValue = std::stod(argv[1]); + // which square root function should we use? #ifdef USE_MYMATH double outputValue = mysqrt(inputValue); #else diff --git a/Help/guide/tutorial/Step6/CMakeLists.txt b/Help/guide/tutorial/Step6/CMakeLists.txt index a78b0ff..5829891 100644 --- a/Help/guide/tutorial/Step6/CMakeLists.txt +++ b/Help/guide/tutorial/Step6/CMakeLists.txt @@ -3,7 +3,7 @@ project(Tutorial) set(CMAKE_CXX_STANDARD 14) -# the version number. +# set the version number set(Tutorial_VERSION_MAJOR 1) set(Tutorial_VERSION_MINOR 0) diff --git a/Help/guide/tutorial/Step6/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step6/MathFunctions/CMakeLists.txt index 2946075..def1140 100644 --- a/Help/guide/tutorial/Step6/MathFunctions/CMakeLists.txt +++ b/Help/guide/tutorial/Step6/MathFunctions/CMakeLists.txt @@ -4,11 +4,11 @@ add_library(MathFunctions mysqrt.cxx) # to find MathFunctions.h, while we don't. # state that we depend on Tutorial_BINARY_DIR but consumers don't, as the # TutorialConfig.h include is an implementation detail - target_include_directories(MathFunctions INTERFACE ${CMAKE_CURRENT_SOURCE_DIR} PRIVATE ${Tutorial_BINARY_DIR} ) +# install rules install(TARGETS MathFunctions DESTINATION lib) install(FILES MathFunctions.h DESTINATION include) diff --git a/Help/guide/tutorial/Step6/directions.txt b/Help/guide/tutorial/Step6/directions.txt deleted file mode 100644 index 42b9f06..0000000 --- a/Help/guide/tutorial/Step6/directions.txt +++ /dev/null @@ -1,104 +0,0 @@ -# Adding a Custom Command and Generated File # - -In this section we will show how you can add a generated source file into the -build process of an application. For this example, we will create a table of -precomputed square roots as part of the build process, and then compile that -table into our application. - -To accomplish this, we first need a program that will generate the table. In the -MathFunctions subdirectory a new source file named MakeTable.cxx will do just that. - - // A simple program that builds a sqrt table - #include <iostream> - #include <fstream> - #include <cmath> - - int main (int argc, char *argv[]) - { - // make sure we have enough arguments - if (argc < 2) { - return 1; - } - - std::ofstream fout(argv[1],std::ios_base::out); - const bool fileOpen = fout.is_open(); - if(fileOpen) { - fout << "double sqrtTable[] = {" << std::endl; - for (int i = 0; i < 10; ++i) { - fout << sqrt(static_cast<double>(i)) << "," << std::endl; - } - // close the table with a zero - fout << "0};" << std::endl; - fout.close(); - } - return fileOpen ? 0 : 1; // return 0 if wrote the file - } - -Note that the table is produced as valid C++ code and that the output filename -is passed in as an argument. - -The next step is to add the appropriate commands to MathFunctions’ CMakeLists -file to build the MakeTable executable and then run it as part of the build -process. A few commands are needed to accomplish this, as shown below: - - # first we add the executable that generates the table - add_executable(MakeTable MakeTable.cxx) - - # add the command to generate the source code - add_custom_command( - OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/Table.h - COMMAND MakeTable ${CMAKE_CURRENT_BINARY_DIR}/Table.h - DEPENDS MakeTable - ) - - # add the main library - add_library(MathFunctions - mysqrt.cxx - ${CMAKE_CURRENT_BINARY_DIR}/Table.h - ) - - target_include_directories(MathFunctions - INTERFACE ${CMAKE_CURRENT_SOURCE_DIR} - PUBLIC ${Tutorial_BINARY_DIR} - # add the binary tree directory to the search path for include files - ${CMAKE_CURRENT_BINARY_DIR} - ) - - install(TARGETS MathFunctions DESTINATION lib) - install(FILES MathFunctions.h DESTINATION include) - -First, the executable for MakeTable is added as any other executable would be -added. Then we add a custom command that specifies how to produce Table.h by -running MakeTable. Next we have to let CMake know that mysqrt.cxx depends on -the generated file Table.h. This is done by adding the generated Table.h to the -list of sources for the library MathFunctions. We also have to add the current -binary directory to the list of include directories so that Table.h can be -found and included by mysqrt.cxx. - -Now let's use the generated table. First, modify mysqrt.cxx to include Table.h. -Next, we can rewrite the mysqrt function to use the table: - - if (x <= 0) { - return 0; - } - - // use the table to help find an initial value - double result = x; - if (x >= 1 && x < 10) { - result = sqrtTable[static_cast<int>(x)]; - } - - // do ten iterations - for (int i = 0; i < 10; ++i) { - if (result <= 0) { - result = 0.1; - } - double delta = x - (result*result); - result = result + 0.5*delta/result; - std::cout << "Computing sqrt of " << x << " to be " << result << std::endl; - } - -Run cmake or cmake-gui to configure the project and then build it with your -chosen build tool. When this project is built it will first build the MakeTable -executable. It will then run MakeTable to produce Table.h. Finally, it will -compile mysqrt.cxx which includes Table.h to produce the MathFunctions library. diff --git a/Help/guide/tutorial/Step6/tutorial.cxx b/Help/guide/tutorial/Step6/tutorial.cxx index c2b89df..8156a9c 100644 --- a/Help/guide/tutorial/Step6/tutorial.cxx +++ b/Help/guide/tutorial/Step6/tutorial.cxx @@ -5,6 +5,7 @@ #include "TutorialConfig.h" +// should we include the MathFunctions header? #ifdef USE_MYMATH # include "MathFunctions.h" #endif @@ -12,6 +13,7 @@ int main(int argc, char* argv[]) { if (argc < 2) { + // report version std::cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR << std::endl; std::cout << "Usage: " << argv[0] << " number" << std::endl; @@ -20,6 +22,7 @@ int main(int argc, char* argv[]) double inputValue = std::stod(argv[1]); + // which square root function should we use? #ifdef USE_MYMATH double outputValue = mysqrt(inputValue); #else diff --git a/Help/guide/tutorial/Step7/CMakeLists.txt b/Help/guide/tutorial/Step7/CMakeLists.txt index 33aa039..17e6a60 100644 --- a/Help/guide/tutorial/Step7/CMakeLists.txt +++ b/Help/guide/tutorial/Step7/CMakeLists.txt @@ -3,7 +3,7 @@ project(Tutorial) set(CMAKE_CXX_STANDARD 14) -# the version number. +# set the version number set(Tutorial_VERSION_MAJOR 1) set(Tutorial_VERSION_MINOR 0) diff --git a/Help/guide/tutorial/Step7/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step7/MathFunctions/CMakeLists.txt index dc3eb98..3c3a816 100644 --- a/Help/guide/tutorial/Step7/MathFunctions/CMakeLists.txt +++ b/Help/guide/tutorial/Step7/MathFunctions/CMakeLists.txt @@ -25,5 +25,6 @@ target_include_directories(MathFunctions ${CMAKE_CURRENT_BINARY_DIR} ) +# install rules install(TARGETS MathFunctions DESTINATION lib) install(FILES MathFunctions.h DESTINATION include) diff --git a/Help/guide/tutorial/Step7/directions.txt b/Help/guide/tutorial/Step7/directions.txt deleted file mode 100644 index 7d7c2ea..0000000 --- a/Help/guide/tutorial/Step7/directions.txt +++ /dev/null @@ -1,40 +0,0 @@ -# Building an Installer # - -Next suppose that we want to distribute our project to other people so that they -can use it. We want to provide both binary and source distributions on a variety -of platforms. This is a little different from the install we did previously in -the Installing and Testing section (Step 4), where we were installing the -binaries that we had built from the source code. In this example we will be -building installation packages that support binary installations and package -management features. To accomplish this we will use CPack to create platform -specific installers. Specifically we need to add a few lines to the bottom of -our top-level CMakeLists.txt file. - - include(InstallRequiredSystemLibraries) - set(CPACK_RESOURCE_FILE_LICENSE "${CMAKE_CURRENT_SOURCE_DIR}/License.txt") - set(CPACK_PACKAGE_VERSION_MAJOR "${Tutorial_VERSION_MAJOR}") - set(CPACK_PACKAGE_VERSION_MINOR "${Tutorial_VERSION_MINOR}") - include(CPack) - -That is all there is to it. We start by including InstallRequiredSystemLibraries. -This module will include any runtime libraries that are needed by the project -for the current platform. Next we set some CPack variables to where we have -stored the license and version information for this project. The version -information makes use of the variables we set earlier in this tutorial. Finally -we include the CPack module which will use these variables and some other -properties of the system you are on to setup an installer. - -The next step is to build the project in the usual manner and then run CPack -on it. To build a binary distribution you would run: - - cpack - -To create a source distribution you would type: - - cpack -C CPackSourceConfig.cmake - -Alternatively, run “make package” or right click the Package target and -“Build Project” from an IDE. - -Run the installer executable found in the binary directory. Then run the -installed executable and verify that it works. diff --git a/Help/guide/tutorial/Step7/tutorial.cxx b/Help/guide/tutorial/Step7/tutorial.cxx index c2b89df..8156a9c 100644 --- a/Help/guide/tutorial/Step7/tutorial.cxx +++ b/Help/guide/tutorial/Step7/tutorial.cxx @@ -5,6 +5,7 @@ #include "TutorialConfig.h" +// should we include the MathFunctions header? #ifdef USE_MYMATH # include "MathFunctions.h" #endif @@ -12,6 +13,7 @@ int main(int argc, char* argv[]) { if (argc < 2) { + // report version std::cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR << std::endl; std::cout << "Usage: " << argv[0] << " number" << std::endl; @@ -20,6 +22,7 @@ int main(int argc, char* argv[]) double inputValue = std::stod(argv[1]); + // which square root function should we use? #ifdef USE_MYMATH double outputValue = mysqrt(inputValue); #else diff --git a/Help/guide/tutorial/Step8/CMakeLists.txt b/Help/guide/tutorial/Step8/CMakeLists.txt index 03dc7c0..86725e8 100644 --- a/Help/guide/tutorial/Step8/CMakeLists.txt +++ b/Help/guide/tutorial/Step8/CMakeLists.txt @@ -3,7 +3,7 @@ project(Tutorial) set(CMAKE_CXX_STANDARD 14) -# the version number. +# set the version number set(Tutorial_VERSION_MAJOR 1) set(Tutorial_VERSION_MINOR 0) @@ -74,6 +74,7 @@ do_test(Tutorial 25 "25 is 5") do_test(Tutorial -25 "-25 is [-nan|nan|0]") do_test(Tutorial 0.0001 "0.0001 is 0.01") +# setup installer include(InstallRequiredSystemLibraries) set(CPACK_RESOURCE_FILE_LICENSE "${CMAKE_CURRENT_SOURCE_DIR}/License.txt") set(CPACK_PACKAGE_VERSION_MAJOR "${Tutorial_VERSION_MAJOR}") diff --git a/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt index dc3eb98..3c3a816 100644 --- a/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt +++ b/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt @@ -25,5 +25,6 @@ target_include_directories(MathFunctions ${CMAKE_CURRENT_BINARY_DIR} ) +# install rules install(TARGETS MathFunctions DESTINATION lib) install(FILES MathFunctions.h DESTINATION include) diff --git a/Help/guide/tutorial/Step8/directions.txt b/Help/guide/tutorial/Step8/directions.txt deleted file mode 100644 index 588d9c6..0000000 --- a/Help/guide/tutorial/Step8/directions.txt +++ /dev/null @@ -1,38 +0,0 @@ -# Adding Support for a Dashboard # - -Adding support for submitting our test results to a dashboard is very easy. We -already defined a number of tests for our project in the earlier steps of this -tutorial. We just have to run those tests and submit them to a dashboard. To -include support for dashboards we include the CTest module in our top-level -CMakeLists.txt. - -Replace: - # enable testing - enable_testing() - -With: - # enable dashboard scripting - include(CTest) - -The CTest module will automatically call enable_testing(), so -we can remove it from our CMake files. - -We will also need to create a CTestConfig.cmake file where we can specify the -name of the project and where to submit the dashboard. - - set(CTEST_PROJECT_NAME "CMakeTutorial") - set(CTEST_NIGHTLY_START_TIME "01:00:00 UTC") - - set(CTEST_DROP_METHOD "http") - set(CTEST_DROP_SITE "my.cdash.org/") - set(CTEST_DROP_LOCATION "/submit.php?project=CMakeTutorial") - set(CTEST_DROP_SITE_CDASH TRUE) - -CTest will read in this file when it runs. To create a simple dashboard you can -run cmake or cmake-gui to configure the project, but do not build it yet. -Instead, change directory to the binary tree, and then run: - 'ctest [-VV] –D Experimental'. On Windows, build the EXPERIMENTAL target. - -Ctest will build and test the project and submit results to the Kitware public -dashboard. The results of your dashboard will be uploaded to Kitware's public -dashboard here: https://my.cdash.org/index.php?project=CMakeTutorial. diff --git a/Help/guide/tutorial/Step8/tutorial.cxx b/Help/guide/tutorial/Step8/tutorial.cxx index c2b89df..8156a9c 100644 --- a/Help/guide/tutorial/Step8/tutorial.cxx +++ b/Help/guide/tutorial/Step8/tutorial.cxx @@ -5,6 +5,7 @@ #include "TutorialConfig.h" +// should we include the MathFunctions header? #ifdef USE_MYMATH # include "MathFunctions.h" #endif @@ -12,6 +13,7 @@ int main(int argc, char* argv[]) { if (argc < 2) { + // report version std::cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR << std::endl; std::cout << "Usage: " << argv[0] << " number" << std::endl; @@ -20,6 +22,7 @@ int main(int argc, char* argv[]) double inputValue = std::stod(argv[1]); + // which square root function should we use? #ifdef USE_MYMATH double outputValue = mysqrt(inputValue); #else diff --git a/Help/guide/tutorial/Step9/CMakeLists.txt b/Help/guide/tutorial/Step9/CMakeLists.txt index 4981fe2..07ab90a 100644 --- a/Help/guide/tutorial/Step9/CMakeLists.txt +++ b/Help/guide/tutorial/Step9/CMakeLists.txt @@ -3,7 +3,7 @@ project(Tutorial) set(CMAKE_CXX_STANDARD 14) -# the version number. +# set the version number set(Tutorial_VERSION_MAJOR 1) set(Tutorial_VERSION_MINOR 0) diff --git a/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt index e651a57..c8cd1dd 100644 --- a/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt +++ b/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt @@ -31,5 +31,6 @@ if(HAVE_LOG AND HAVE_EXP) PRIVATE "HAVE_LOG" "HAVE_EXP") endif() +# install rules install(TARGETS MathFunctions DESTINATION lib) install(FILES MathFunctions.h DESTINATION include) diff --git a/Help/guide/tutorial/Step9/directions.txt b/Help/guide/tutorial/Step9/directions.txt deleted file mode 100644 index 8771637..0000000 --- a/Help/guide/tutorial/Step9/directions.txt +++ /dev/null @@ -1,166 +0,0 @@ -# Mixing Static and Shared # - -In this section we will show how by using the BUILD_SHARED_LIBS variable we can -control the default behavior of add_library, and allow control over how -libraries without an explicit type ( STATIC/SHARED/MODULE/OBJECT ) are built. - -To accomplish this we need to add BUILD_SHARED_LIBS to the top level -CMakeLists.txt. We use the option command as it allows users to optionally -select if the value should be On or Off. - -Next we are going to refactor MathFunctions to become a real library that -encapsulates using mysqrt or sqrt, instead of requiring the calling code -to do this logic. This will also mean that USE_MYMATH will not control building -MathFuctions, but instead will control the behavior of this library. - -The first step is to update the starting section of the top level CMakeLists.txt -to look like: - - cmake_minimum_required(VERSION 3.3) - project(Tutorial) - - # control where the static and shared libraries are built so that on windows - # we don't need to tinker with the path to run the executable - set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}") - set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}") - - set(CMAKE_CXX_STANDARD 11) - set(CMAKE_CXX_STANDARD_REQUIRED True) - - option(BUILD_SHARED_LIBS "Build using shared libraries" ON) - - # the version number. - set(Tutorial_VERSION_MAJOR 1) - set(Tutorial_VERSION_MINOR 0) - - # configure a header file to pass the version number only - configure_file( - "${PROJECT_SOURCE_DIR}/TutorialConfig.h.in" - "${PROJECT_BINARY_DIR}/TutorialConfig.h" - ) - - # add the MathFunctions library - add_subdirectory(MathFunctions) - - # add the executable - add_executable(Tutorial tutorial.cxx) - target_link_libraries(Tutorial PUBLIC MathFunctions) - -Now that we have made MathFunctions always be used, we will need to update -the logic of that library. So, in MathFunctions/CMakeLists.txt we need to -create a SqrtLibrary that will conditionally be built when USE_MYMATH is -enabled. Now, since this is a tutorial, we are going to explicitly require -that SqrtLibrary is built statically. - -The end result is that MathFunctions/CMakeLists.txt should look like: - - # add the library that runs - add_library(MathFunctions MathFunctions.cxx) - - # state that anybody linking to us needs to include the current source dir - # to find MathFunctions.h, while we don't. - target_include_directories(MathFunctions - INTERFACE ${CMAKE_CURRENT_SOURCE_DIR} - ) - - # should we use our own math functions - option(USE_MYMATH "Use tutorial provided math implementation" ON) - if(USE_MYMATH) - - # does this system provide the log and exp functions? - include(CheckSymbolExists) - set(CMAKE_REQUIRED_LIBRARIES "m") - check_symbol_exists(log "math.h" HAVE_LOG) - check_symbol_exists(exp "math.h" HAVE_EXP) - - # first we add the executable that generates the table - add_executable(MakeTable MakeTable.cxx) - - # add the command to generate the source code - add_custom_command( - OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/Table.h - COMMAND MakeTable ${CMAKE_CURRENT_BINARY_DIR}/Table.h - DEPENDS MakeTable - ) - - # library that just does sqrt - add_library(SqrtLibrary STATIC - mysqrt.cxx - ${CMAKE_CURRENT_BINARY_DIR}/Table.h - ) - - # state that we depend on our binary dir to find Table.h - target_include_directories(SqrtLibrary PRIVATE - ${CMAKE_CURRENT_BINARY_DIR} - ) - - target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH") - if(HAVE_LOG AND HAVE_EXP) - target_compile_definitions(SqrtLibrary - PRIVATE "HAVE_LOG" "HAVE_EXP") - endif() - - target_link_libraries(MathFunctions PRIVATE SqrtLibrary) - endif() - - # define the symbol stating we are using the declspec(dllexport) when - # building on windows - target_compile_definitions(MathFunctions PRIVATE "EXPORTING_MYMATH") - - install(TARGETS MathFunctions DESTINATION lib) - install(FILES MathFunctions.h DESTINATION include) - -Next, update MathFunctions/mysqrt.cxx to use the mathfunctions and detail namespaces: - - #include <iostream> - #include "MathFunctions.h" - - // include the generated table - #include "Table.h" - - #include <cmath> - - namespace mathfunctions { - namespace detail { - // a hack square root calculation using simple operations - double mysqrt(double x) - { - ... - - return result; - } - } - } - -We also need to make some changes in tutorial.cxx, so that it no longer uses USE_MYMATH: -1. Always include MathFunctions.h -2. Always use mathfunctions::sqrt - -Finally, update MathFunctions/MathFunctions.h to use dll export defines: - - #if defined(_WIN32) - #if defined(EXPORTING_MYMATH) - #define DECLSPEC __declspec(dllexport) - #else - #define DECLSPEC __declspec(dllimport) - #endif - #else //non windows - #define DECLSPEC - #endif - - namespace mathfunctions - { - double DECLSPEC sqrt(double x); - } - -At this point, if you build everything, you will notice that linking fails -as we are combining a static library without position enabled code with a -library that has position enabled code. This solution to this is to explicitly -set the POSITION_INDEPENDENT_CODE target property of SqrtLibrary to be True no -matter the build type. - -Exercise: We modified MathFunctions.h to use dll export defines. Using CMake -documentation can you find a helper module to simplify this? - -Exercise: Determine what command is enabling PIC for SqrtLibrary. -What happens if we remove said command? diff --git a/Help/guide/tutorial/Step9/tutorial.cxx b/Help/guide/tutorial/Step9/tutorial.cxx index 6c41859..3286bc8 100644 --- a/Help/guide/tutorial/Step9/tutorial.cxx +++ b/Help/guide/tutorial/Step9/tutorial.cxx @@ -6,6 +6,7 @@ #include "TutorialConfig.h" +// should we include the MathFunctions header? #ifdef USE_MYMATH # include "MathFunctions.h" #endif @@ -13,6 +14,7 @@ int main(int argc, char* argv[]) { if (argc < 2) { + // report version std::cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR << std::endl; std::cout << "Usage: " << argv[0] << " number" << std::endl; @@ -21,6 +23,7 @@ int main(int argc, char* argv[]) double inputValue = std::stod(argv[1]); + // which square root function should we use? #ifdef USE_MYMATH double outputValue = mysqrt(inputValue); #else diff --git a/Help/guide/tutorial/index.rst b/Help/guide/tutorial/index.rst index be906af..673f284 100644 --- a/Help/guide/tutorial/index.rst +++ b/Help/guide/tutorial/index.rst @@ -1,2 +1,719 @@ CMake Tutorial ************** + +A Basic Starting Point (Step 1) +=============================== + +Adding a Version Number and Configured Header File +-------------------------------------------------- + +The first feature we will add is to provide our executable and project with a +version number. While we could do this exclusively in the source code, using +CMakeLists provides more flexibility. + +To add a version number we modify the CMakeLists file as follows: + +.. literalinclude:: Step2/CMakeLists.txt + :language: cmake + :start-after: # set the version number + :end-before: # configure a header file + +We then create a ``TutorialConfig.h.in`` file in the source tree with the +following contents: + +.. literalinclude:: Step1/TutorialConfig.h.in + :language: cmake + +When CMake configures this header file the values for +``@Tutorial_VERSION_MAJOR@`` and ``@Tutorial_VERSION_MINOR@`` will be +replaced by the values from the CMakeLists file. Next we modify +``tutorial.cxx`` to include the configured header file and to make use of the +version numbers. The updated source code is listed below. + +.. literalinclude:: Step2/tutorial.cxx + :language: c++ + :start-after: // report version + :end-before: return 1; + + +Specify the C++ Standard +------------------------- + +Next let's add some C++11 features to our project. We will need to explicitly +state in the CMake code that it should use the correct flags. The easiest way +to enable C++11 support for CMake is by using the ``CMAKE_CXX_STANDARD`` +variable. + +First, replace ``atof`` with ``std::stod`` in ``tutorial.cxx``. + +Then, set the ``CMAKE_CXX_STANDARD`` variable in the CMakeLists file. + +Which variable can we set in the CMakeLists file to treat the +``CMAKE_CXX_STANDARD`` value as a requirement? + +Build and Test +-------------- + +Run **cmake** or **cmake-gui** to configure the project and then build it +with your chosen build tool. + +cd to the directory where Tutorial was built (likely the make directory or +a Debug or Release build configuration subdirectory) and run these commands: + +.. code-block:: console + + Tutorial 4294967296 + Tutorial 10 + Tutorial + +Adding a Library (Step 2) +========================= + +Now we will add a library to our project. This library will contain our own +implementation for computing the square root of a number. The executable can +then use this library instead of the standard square root function provided by +the compiler. + +For this tutorial we will put the library into a subdirectory +called MathFunctions. It will have the following one line CMakeLists file: + +.. literalinclude:: Step2/MathFunctions/CMakeLists.txt + :language: cmake + +The source file ``mysqrt.cxx`` has one function called ``mysqrt`` that +provides similar functionality to the compiler’s ``sqrt`` function. To make use +of the new library we add an ``add_subdirectory`` call in the top-level +CMakeLists file so that the library will get built. We add the new library to +the executable, and add MathFunctions as an include directory so that the +``mqsqrt.h`` header file can be found. The last few lines of the top-level +CMakeLists file now look like: + +.. code-block:: cmake + + # add the MathFunctions library + add_subdirectory(MathFunctions) + + # add the executable + add_executable(Tutorial tutorial.cxx) + + target_link_libraries(Tutorial MathFunctions) + + # add the binary tree to the search path for include files + # so that we will find TutorialConfig.h + target_include_directories(Tutorial PUBLIC + "${PROJECT_BINARY_DIR}" + "${PROJECT_SOURCE_DIR}/MathFunctions" + ) + +Now let us make the MathFunctions library optional. While for the tutorial +there really isn’t any need to do so, for larger projects this is a common +occurrence. The first step is to add an option to the top-level CMakeLists +file. + +.. literalinclude:: Step3/CMakeLists.txt + :language: cmake + :start-after: # should we use our own math functions + :end-before: # set the version number + +This will show up in the CMake GUI and ccmake with a default value of ON +that can be changed by the user. This setting will be stored in the cache so +that the user does not need to set the value each time they run CMake on this +build directory. + +The next change is to make building and linking the MathFunctions library +conditional. To do this we change the end of the top-level CMakeLists file to +look like the following: + +.. literalinclude:: Step3/CMakeLists.txt + :language: cmake + :start-after: # add the MathFunctions library? + +Note the use of the variables ``EXTRA_LIBS`` and ``EXTRA_INCLUDES`` to collect +up any optional libraries to later be linked into the executable. This is a +classic approach when dealing with many optional components, we will cover the +modern approach in the next step. + +The corresponding changes to the source code are fairly straightforward. First, +include the MathFunctions header if we need it: + +.. literalinclude:: Step3/tutorial.cxx + :language: c++ + :start-after: // should we include the MathFunctions header + :end-before: int main + +Then make which square root function is used dependent on ``USE_MYMATH``: + +.. literalinclude:: Step3/tutorial.cxx + :language: c++ + :start-after: // which square root function should we use? + :end-before: std::cout << "The square root of + +Since the source code now requires ``USE_MYMATH`` we can add it to +``TutorialConfig.h.in`` with the following line: + +.. literalinclude:: Step3/TutorialConfig.h.in + :language: c + :lines: 4 + +Run **cmake** or **cmake-gui** to configure the project and then build it +with your chosen build tool. Then run the built Tutorial executable. + +Which function gives better results, Step1’s sqrt or Step2’s mysqrt? + +Adding Usage Requirements for Library (Step 3) +============================================== + +Usage requirements allow for far better control over a library or executable's +link and include line while also giving more control over the transitive +property of targets inside CMake. The primary commands that leverage usage +requirements are: + + - ``target_compile_definitions`` + - ``target_compile_options`` + - ``target_include_directories`` + - ``target_link_libraries`` + +First up is MathFunctions. We first state that anybody linking to MathFunctions +needs to include the current source directory, while MathFunctions itself +doesn't. So this can become an ``INTERFACE`` usage requirement. + +Remember ``INTERFACE`` means things that consumers require but the producer +doesn't. Update ``MathFunctions/CMakeLists.txt`` with: + +.. literalinclude:: Step4/MathFunctions/CMakeLists.txt + :language: cmake + :start-after: # to find MathFunctions.h + +Now that we've specified usage requirements for MathFunctions we can safely +remove our uses of the ``EXTRA_INCLUDES`` variable from the top-level +CMakeLists. + +Once this is done, run **cmake** or **cmake-gui** to configure the project +and then build it with your chosen build tool. + +Installing and Testing (Step 4) +=============================== + +Now we can start adding install rules and testing support to our project. + +Install Rules +------------- + +The install rules are fairly simple for MathFunctions we want to install the +library and header file and for the application we want to install the +executable and configured header. + +So to ``MathFunctions/CMakeLists.txt`` we add: + +.. literalinclude:: Step5/MathFunctions/CMakeLists.txt + :language: cmake + :start-after: # install rules + +And the to top-level ``CMakeLists.txt`` we add: + +.. literalinclude:: Step5/CMakeLists.txt + :language: cmake + :start-after: # add the install targets + :end-before: # enable testing + +That is all that is needed to create a basic local install of the tutorial. + +Run **cmake** or **cmake-gui** to configure the project and then build it +with your chosen build tool. Build the ``install`` target by typing +``make install`` from the command line or build the ``INSTALL`` target from +an IDE. This will install the appropriate header files, libraries, and +executables. + +Verify that the installed Tutorial runs. Note: The CMake variable +``CMAKE_INSTALL_PREFIX`` is used to determine the root of where the files will +be installed. + +Testing Support +--------------- + +Next let's test our application. At the end of the top-level CMakeLists file we +can add a number of basic tests to verify that the application is +working correctly. + +.. literalinclude:: Step5/CMakeLists.txt + :language: cmake + :start-after: # enable testing + +The first test simply verifies that the application runs, does not segfault or +otherwise crash, and has a zero return value. This is the basic form of a CTest +test. + +The next test makes use of the ``PASS_REGULAR_EXPRESSION`` test property to +verify that the output of the test contains certain strings, in this case: +verifying that the the usage message is printed when an incorrect number of +arguments are provided. + +Lastly, we have a function called ``do_test`` that runs the application and +verifies that the computed square root is correct for given input. For each +invocation of ``do_test``, another test is added to the project with a name, +input, and expected results based on the passed arguments. + +Rebuild the application and then cd to the binary directory and run +``ctest -N`` and ``ctest -VV``. + +Adding System Introspection (Step 5) +==================================== + +Let us consider adding some code to our project that depends on features the +target platform may not have. For this example, we will add some code that +depends on whether or not the target platform has the ``log`` and ``exp`` +functions. Of course almost every platform has these functions but for this +tutorial assume that they are not common. + +If the platform has ``log`` and ``exp`` then we will use them to compute the +square root in the ``mysqrt`` function. We first test for the availability of +these functions using the ``CheckSymbolExists.cmake`` macro in the top-level +CMakeLists file as follows: + +.. literalinclude:: Step6/CMakeLists.txt + :language: cmake + :start-after: # does this system provide the log and exp functions? + :end-before: # should we use our own math functions + +Now let's add these defines to ``TutorialConfig.h.in`` so that we can use them +from ``mysqrt.cxx``: + +.. literalinclude:: Step6/TutorialConfig.h.in + :language: c + :start-after: // does the platform provide exp and log functions? + +Finally, in the ``mysqrt`` function we can provide an alternate implementation +based on ``log`` and ``exp`` if they are available on the system using the +following code: + +.. literalinclude:: Step6/MathFunctions/mysqrt.cxx + :language: c++ + :start-after: // if we have both log and exp then use them + :end-before: #else + +Run **cmake** or **cmake-gui** to configure the project and then build it +with your chosen build tool. + +You will notice that even though ``HAVE_LOG`` and ``HAVE_EXP`` are both +defined ``mysqrt`` isn't using them. We should realize quickly that we have +forgotten to include ``TutorialConfig.h`` in ``mysqrt.cxx``. + +After making this update, go ahead and build the project again. + +Run the built Tutorial executable. Which function gives better results now, +Step1’s sqrt or Step5’s mysqrt? + +**Exercise**: Why is it important that we configure ``TutorialConfig.h.in`` +after the checks for ``HAVE_LOG`` and ``HAVE_EXP``? What would happen if we +inverted the two? + +**Exercise**: Is there a better place for us to save the ``HAVE_LOG`` and +``HAVE_EXP`` values other than in ``TutorialConfig.h``? + +Adding a Custom Command and Generated File (Step 6) +=================================================== + +In this section, we will add a generated source file into the build process +of an application. For this example, we will create a table of precomputed +square roots as part of the build process, and then compile that +table into our application. + +To accomplish this, we first need a program that will generate the table. In +the MathFunctions subdirectory a new source file named ``MakeTable.cxx`` will +do just that. + +.. literalinclude:: Step7/MathFunctions/MakeTable.cxx + :language: c++ + +Note that the table is produced as valid C++ code and that the output filename +is passed in as an argument. + +The next step is to add the appropriate commands to MathFunctions' CMakeLists +file to build the MakeTable executable and then run it as part of the build +process. A few commands are needed to accomplish this. + +First, the executable for ``MakeTable`` is added as any other executable would +be added. + +.. literalinclude:: Step7/MathFunctions/CMakeLists.txt + :language: cmake + :start-after: # first we add the executable that generates the table + :end-before: # add the command to generate the source code + +Then we add a custom command that specifies how to produce ``Table.h`` +by running MakeTable. + +.. literalinclude:: Step7/MathFunctions/CMakeLists.txt + :language: cmake + :start-after: # add the command to generate the source code + :end-before: # add the main library + +Next we have to let CMake know that ``mysqrt.cxx`` depends on the generated +file ``Table.h``. This is done by adding the generated ``Table.h`` to the list +of sources for the library MathFunctions. + +.. literalinclude:: Step7/MathFunctions/CMakeLists.txt + :language: cmake + :start-after: # add the main library + :end-before: # state that anybody linking + +We also have to add the current binary directory to the list of include +directories so that ``Table.h`` can be found and included by ``mysqrt.cxx``. + +.. literalinclude:: Step7/MathFunctions/CMakeLists.txt + :start-after: # state that we depend on our bin + :end-before: # install rules + +Now let's use the generated table. First, modify ``mysqrt.cxx`` to include +``Table.h``. Next, we can rewrite the mysqrt function to use the table: + +.. literalinclude:: Step7/MathFunctions/mysqrt.cxx + :language: c++ + :start-after: // a hack square root calculation using simple operations + +Run **cmake** or **cmake-gui** to configure the project and then build it +with your chosen build tool. When this project is built it will first build +the ``MakeTable`` executable. It will then run ``MakeTable`` to produce +``Table.h``. Finally, it will compile ``mysqrt.cxx`` which includes +``Table.h`` to produce the MathFunctions library. + +Building an Installer (Step 7) +============================== + +Next suppose that we want to distribute our project to other people so that +they can use it. We want to provide both binary and source distributions on a +variety of platforms. This is a little different from the install we did +previously in `Installing and Testing (Step 4)`_ , where we were +installing the binaries that we had built from the source code. In this +example we will be building installation packages that support binary +installations and package management features. To accomplish this we will use +CPack to create platform specific installers. Specifically we need to add +a few lines to the bottom of our top-level ``CMakeLists.txt`` file. + +.. literalinclude:: Step8/CMakeLists.txt + :language: cmake + :start-after: # setup installer + +That is all there is to it. We start by including +``InstallRequiredSystemLibraries``. This module will include any runtime +libraries that are needed by the project for the current platform. Next we +set some CPack variables to where we have stored the license and version +information for this project. The version information makes use of the +variables we set earlier in this tutorial. Finally we include the CPack +module which will use these variables and some other properties of the system +you are on to setup an installer. + +The next step is to build the project in the usual manner and then run +CPack on it. To build a binary distribution you would run: + +.. code-block:: console + + cpack + +To create a source distribution you would type: + +.. code-block:: console + + cpack -C CPackSourceConfig.cmake + +Alternatively, run ``make package`` or right click the ``Package`` target and +``Build Project`` from an IDE. + +Run the installer executable found in the binary directory. Then run the +installed executable and verify that it works. + +Adding Support for a Dashboard (Step 8) +======================================= + +Adding support for submitting our test results to a dashboard is very easy. We +already defined a number of tests for our project in the earlier steps of this +tutorial. We just have to run those tests and submit them to a dashboard. To +include support for dashboards we include the CTest module in our top-level +``CMakeLists.txt``. + +Replace: + +.. code-block:: cmake + + # enable testing + enable_testing() + +With: + +.. code-block:: cmake + + # enable dashboard scripting + include(CTest) + +The CTest module will automatically call ``enable_testing()``, so +we can remove it from our CMake files. + +We will also need to create a ``CTestConfig.cmake`` file where we can specify +the name of the project and where to submit the dashboard. + +.. literalinclude:: Step9/CTestConfig.cmake + :language: cmake + +CTest will read in this file when it runs. To create a simple dashboard you can +run **cmake** or **cmake-gui** to configure the project, but do not build it +yet. Instead, change directory to the binary tree, and then run: + +.. code-block:: console + + 'ctest [-VV] –D Experimental' + +On Windows, build the EXPERIMENTAL target. + +Ctest will build and test the project and submit the results to the Kitware +public dashboard. The results of your dashboard will be uploaded to Kitware's +public dashboard here: https://my.cdash.org/index.php?project=CMakeTutorial. + +Mixing Static and Shared (Step 9) +================================= + +In this section we will show how by using the ``BUILD_SHARED_LIBS`` variable +we can control the default behavior of ``add_library``, and allow control +over how libraries without an explicit type (STATIC/SHARED/MODULE/OBJECT) are +built. + +To accomplish this we need to add ``BUILD_SHARED_LIBS`` to the top-level +``CMakeLists.txt``. We use the ``option`` command as it allows users to +optionally select if the value should be On or Off. + +Next we are going to refactor MathFunctions to become a real library that +encapsulates using ``mysqrt`` or ``sqrt``, instead of requiring the calling +code to do this logic. This will also mean that ``USE_MYMATH`` will not control +building MathFuctions, but instead will control the behavior of this library. + +The first step is to update the starting section of the top-level +``CMakeLists.txt`` to look like: + +.. literalinclude:: Step10/CMakeLists.txt + :language: cmake + :start-after: set(Tutorial_VERSION_MINOR + :end-before: # add the binary tree + +Now that we have made MathFunctions always be used, we will need to update +the logic of that library. So, in ``MathFunctions/CMakeLists.txt`` we need to +create a SqrtLibrary that will conditionally be built when ``USE_MYMATH`` is +enabled. Now, since this is a tutorial, we are going to explicitly require +that SqrtLibrary is built statically. + +The end result is that ``MathFunctions/CMakeLists.txt`` should look like: + +.. literalinclude:: Step10/MathFunctions/CMakeLists.txt + :language: cmake + :lines: 1-40,46- + +Next, update ``MathFunctions/mysqrt.cxx`` to use the ``mathfunctions`` and +``detail`` namespaces: + +.. literalinclude:: Step10/MathFunctions/mysqrt.cxx + :language: c++ + +We also need to make some changes in ``tutorial.cxx``, so that it no longer +uses ``USE_MYMATH``: + +#. Always include ``MathFunctions.h`` +#. Always use ``mathfunctions::sqrt`` + +Finally, update ``MathFunctions/MathFunctions.h`` to use dll export defines: + +.. literalinclude:: Step10/MathFunctions/MathFunctions.h + :language: c++ + +At this point, if you build everything, you will notice that linking fails +as we are combining a static library without position enabled code with a +library that has position enabled code. The solution to this is to explicitly +set the ``POSITION_INDEPENDENT_CODE`` target property of SqrtLibrary to be +True no matter the build type. + +**Exercise**: We modified ``MathFunctions.h`` to use dll export defines. +Using CMake documentation can you find a helper module to simplify this? + +Adding Generator Expressions (Step 10) +====================================== + +Generator expressions are evaluated during build system generation to produce +information specific to each build configuration. + +Generator expressions are allowed in the context of many target properties, +such as ``LINK_LIBRARIES``, ``INCLUDE_DIRECTORIES``, ``COMPILE_DEFINITIONS`` +and others. They may also be used when using commands to populate those +properties, such as ``target_link_libraries()``, +``target_include_directories()``, +``target_compile_definitions()`` and others. + +Generator expressions may be used to enable conditional linking, conditional +definitions used when compiling, conditional include directories and more. +The conditions may be based on the build configuration, target properties, +platform information or any other queryable information. + +There are different types of generator expressions including Logical, +Informational, and Output expressions. + +Logical expressions are used to create conditional output. The basic +expressions are the 0 and 1 expressions. A ``$<0:...>`` results in the empty +string, and ``<1:...>`` results in the content of "...". They can also be +nested. + +For example: + +.. code-block:: cmake + + if(HAVE_LOG AND HAVE_EXP) + target_compile_definitions(SqrtLibrary + PRIVATE "HAVE_LOG" "HAVE_EXP") + endif() + +Can be rewritten with generator expressions: + +.. code-block:: cmake + + target_compile_definitions(SqrtLibrary PRIVATE + "$<$<BOOL:${HAVE_LOG}>:HAVE_LOG>" + "$<$<BOOL:${HAVE_EXP}>:HAVE_EXP>" + ) + +Note that ``${HAVE_LOG}`` is evaluated at CMake configure time while +``$<$<BOOL:${HAVE_LOG}>:HAVE_LOG>`` is evaluated at build system generation +time. + +Adding Export Configuration (Step 11) +===================================== + +During `Installing and Testing (Step 4)`_ of the tutorial we added the ability +for CMake to install the library and headers of the project. During +`Building an Installer (Step 7)`_ we added the ability to package up this +information so it could be distributed to other people. + +The next step is to add the necessary information so that other CMake projects +can use our project, be it from a build directory, a local install or when +packaged. + +The first step is to update our ``install(TARGETS)`` commands to not only +specify a ``DESTINATION`` but also an ``EXPORT``. The ``EXPORT`` keyword +generates and installs a CMake file containing code to import all targets +listed in the install command from the installation tree. So let's go ahead +and explicitly ``EXPORT`` the MathFunctions library by updating the +``install`` command in ``MathFunctions/CMakeLists.txt`` to look like: + +.. literalinclude:: Complete/MathFunctions/CMakeLists.txt + :language: cmake + :start-after: # install rules + +Now that we have MathFunctions being exported, we also need to explicitly +install the generated ``MathFunctionsTargets.cmake`` file. This is done by +adding the following to the bottom of the top-level ``CMakeLists.txt``: + +.. literalinclude:: Complete/CMakeLists.txt + :language: cmake + :start-after: # install the configuration targets + :end-before: include(CMakePackageConfigHelpers) + +At this point you should try and run CMake. If everything is setup properly +you will see that CMake will generate an error that looks like: + +.. code-block:: console + + Target "MathFunctions" INTERFACE_INCLUDE_DIRECTORIES property contains + path: + + "/Users/robert/Documents/CMakeClass/Tutorial/Step11/MathFunctions" + + which is prefixed in the source directory. + +What CMake is trying to say is that during generating the export information +it will export a path that is intrinsically tied to the current machine and +will not be valid on other machines. The solution to this is to update the +MathFunctions ``target_include_directories`` to understand that it needs +different ``INTERFACE`` locations when being used from within the build +directory and from an install / package. This means converting the +``target_include_directories`` call for MathFunctions to look like: + +.. literalinclude:: Complete/MathFunctions/CMakeLists.txt + :language: cmake + :start-after: # to find MathFunctions.h, while we don't. + :end-before: # should we use our own math functions + +Once this has been updated, we can re-run CMake and see verify that it doesn't +warn anymore. + +At this point, we have CMake properly packaging the target information that is +required but we will still need to generate a ``MathFunctionsConfig.cmake`` so +that the CMake ``find_package command`` can find our project. So let's go +ahead and add a new file to the top-level of the project called +``Config.cmake.in`` with the following contents: + +.. literalinclude:: Complete/Config.cmake.in + +Then, to properly configure and install that file, add the following to the +bottom of the top-level CMakeLists: + +.. literalinclude:: Complete/CMakeLists.txt + :language: cmake + :start-after: # install the configuration targets + :end-before: # generate the export + +At this point, we have generated a relocatable CMake Configuration for our +project that can be used after the project has been installed or packaged. If +we want our project to also be used from a build directory we only have to add +the following to the bottom of the top level CMakeLists: + +.. literalinclude:: Complete/CMakeLists.txt + :language: cmake + :start-after: # needs to be after the install(TARGETS ) command + +With this export call we now generate a ``Targets.cmake``, allowing the +configured ``MathFunctionsConfig.cmake`` in the build directory to be used by +other projects, without needing it to be installed. + +Import a CMake Project (Consumer) +================================= + +This examples shows how a project can find other CMake packages that +generate ``Config.cmake`` files. + +It also shows how to state a project's external dependencies when generating +a ``Config.cmake``. + +Packaging Debug and Release (MultiPackage) +========================================== + +By default CMake is model is that a build directory only contains a single +configuration, be it Debug, Release, MinSizeRel, or RelWithDebInfo. + +But it is possible to setup CPack to bundle multiple build directories at the +same time to build a package that contains multiple configurations of the +same project. + +First we need to ahead and construct a directory called ``multi_config`` this +will contain all the builds that we want to package together. + +Second create a ``debug`` and ``release`` directory underneath +``multi_config``. At the end you should have a layout that looks like: + +─ multi_config + ├── debug + └── release + +Now we need to setup debug and release builds, which would roughly entail +the following: + +.. code-block:: console + + cd debug + cmake -DCMAKE_BUILD_TYPE=Debug ../../MultiPackage/ + cmake --build . + cd ../release + cmake -DCMAKE_BUILD_TYPE=Release ../../MultiPackage/ + cmake --build . + cd .. + + +Now that both the debug and release builds are complete we can now use +the custom MultiCPackConfig to package both builds into a single release. + +.. code-block:: console + + cpack --config ../../MultiPackage/MultiCPackConfig.cmake |