diff options
Diffstat (limited to 'Help/guide/tutorial/Step9')
-rw-r--r-- | Help/guide/tutorial/Step9/CMakeLists.txt | 80 | ||||
-rw-r--r-- | Help/guide/tutorial/Step9/CTestConfig.cmake | 15 | ||||
-rw-r--r-- | Help/guide/tutorial/Step9/License.txt | 2 | ||||
-rw-r--r-- | Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt | 35 | ||||
-rw-r--r-- | Help/guide/tutorial/Step9/MathFunctions/MakeTable.cxx | 25 | ||||
-rw-r--r-- | Help/guide/tutorial/Step9/MathFunctions/MathFunctions.cxx | 18 | ||||
-rw-r--r-- | Help/guide/tutorial/Step9/MathFunctions/MathFunctions.h | 1 | ||||
-rw-r--r-- | Help/guide/tutorial/Step9/MathFunctions/mysqrt.cxx | 41 | ||||
-rw-r--r-- | Help/guide/tutorial/Step9/MathFunctions/mysqrt.h | 6 | ||||
-rw-r--r-- | Help/guide/tutorial/Step9/TutorialConfig.h.in | 3 | ||||
-rw-r--r-- | Help/guide/tutorial/Step9/directions.txt | 166 | ||||
-rw-r--r-- | Help/guide/tutorial/Step9/tutorial.cxx | 33 |
12 files changed, 425 insertions, 0 deletions
diff --git a/Help/guide/tutorial/Step9/CMakeLists.txt b/Help/guide/tutorial/Step9/CMakeLists.txt new file mode 100644 index 0000000..4981fe2 --- /dev/null +++ b/Help/guide/tutorial/Step9/CMakeLists.txt @@ -0,0 +1,80 @@ +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) + +# 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) + +# should we use our own math functions +option(USE_MYMATH "Use tutorial provided math implementation" ON) + +# 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? +if(USE_MYMATH) + add_subdirectory(MathFunctions) + list(APPEND EXTRA_LIBS MathFunctions) +endif() + +# add the executable +add_executable(Tutorial tutorial.cxx) +target_link_libraries(Tutorial PUBLIC ${EXTRA_LIBS}) + +# add the binary tree to the search path for include files +# so that we will find TutorialConfig.h +target_include_directories(Tutorial PUBLIC + "${PROJECT_BINARY_DIR}" + ) + +# add the install targets +install(TARGETS Tutorial DESTINATION bin) +install(FILES "${PROJECT_BINARY_DIR}/TutorialConfig.h" + DESTINATION include + ) + +# enable testing +include(CTest) + +# does the application run +add_test(NAME Runs COMMAND Tutorial 25) + +# does the usage message work? +add_test(NAME Usage COMMAND Tutorial) +set_tests_properties(Usage + PROPERTIES PASS_REGULAR_EXPRESSION "Usage:.*number" + ) + +# define a function to simplify adding tests +function(do_test target arg result) + add_test(NAME Comp${arg} COMMAND ${target} ${arg}) + set_tests_properties(Comp${arg} + PROPERTIES PASS_REGULAR_EXPRESSION ${result} + ) +endfunction(do_test) + +# do a bunch of result based tests +do_test(Tutorial 4 "4 is 2") +do_test(Tutorial 9 "9 is 3") +do_test(Tutorial 5 "5 is 2.236") +do_test(Tutorial 7 "7 is 2.645") +do_test(Tutorial 25 "25 is 5") +do_test(Tutorial -25 "-25 is [-nan|nan|0]") +do_test(Tutorial 0.0001 "0.0001 is 0.01") + +include(InstallRequiredSystemLibraries) +set(CPACK_RESOURCE_FILE_LICENSE "${CMAKE_CURRENT_SOURCE_DIR}/License.txt") +set(CPACK_PACKAGE_VERSION_MAJOR "${Tutorial_VERSION_MAJOR}") +set(CPACK_PACKAGE_VERSION_MINOR "${Tutorial_VERSION_MINOR}") +include(CPack) diff --git a/Help/guide/tutorial/Step9/CTestConfig.cmake b/Help/guide/tutorial/Step9/CTestConfig.cmake new file mode 100644 index 0000000..7a927ac --- /dev/null +++ b/Help/guide/tutorial/Step9/CTestConfig.cmake @@ -0,0 +1,15 @@ +## This file should be placed in the root directory of your project. +## Then modify the CMakeLists.txt file in the root directory of your +## project to incorporate the testing dashboard. +## +## # The following are required to submit to the CDash dashboard: +## ENABLE_TESTING() +## INCLUDE(CTest) + +set(CTEST_PROJECT_NAME "CMakeTutorial") +set(CTEST_NIGHTLY_START_TIME "00:00:00 EST") + +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) diff --git a/Help/guide/tutorial/Step9/License.txt b/Help/guide/tutorial/Step9/License.txt new file mode 100644 index 0000000..c62d00b --- /dev/null +++ b/Help/guide/tutorial/Step9/License.txt @@ -0,0 +1,2 @@ +This is the open source License.txt file introduced in +CMake/Tutorial/Step7... diff --git a/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt new file mode 100644 index 0000000..e651a57 --- /dev/null +++ b/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt @@ -0,0 +1,35 @@ +# 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 + ) + +# state that anybody linking to us needs to include the current source dir +# to find MathFunctions.h, while we don't. +# state that we depend on our binary dir to find Table.h +target_include_directories(MathFunctions + INTERFACE ${CMAKE_CURRENT_SOURCE_DIR} + PRIVATE ${CMAKE_CURRENT_BINARY_DIR} + ) + +# use compile definitions to state if we have enabled USE_MYMATH +# and that anything that links to use will get this define +target_compile_definitions(MathFunctions INTERFACE "USE_MYMATH") + +if(HAVE_LOG AND HAVE_EXP) + target_compile_definitions(MathFunctions + PRIVATE "HAVE_LOG" "HAVE_EXP") +endif() + +install(TARGETS MathFunctions DESTINATION lib) +install(FILES MathFunctions.h DESTINATION include) diff --git a/Help/guide/tutorial/Step9/MathFunctions/MakeTable.cxx b/Help/guide/tutorial/Step9/MathFunctions/MakeTable.cxx new file mode 100644 index 0000000..ee58556 --- /dev/null +++ b/Help/guide/tutorial/Step9/MathFunctions/MakeTable.cxx @@ -0,0 +1,25 @@ +// A simple program that builds a sqrt table +#include <cmath> +#include <fstream> +#include <iostream> + +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 +} diff --git a/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.cxx new file mode 100644 index 0000000..5351184 --- /dev/null +++ b/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.cxx @@ -0,0 +1,18 @@ + +#include "MathFunctions.h" +#include <cmath> + +#ifdef USE_MYMATH +# include "mysqrt.h" +#endif + +namespace mathfunctions { +double sqrt(double x) +{ +#ifdef USE_MYMATH + return detail::mysqrt(x); +#else + return std::sqrt(x); +#endif +} +} diff --git a/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.h b/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.h new file mode 100644 index 0000000..cd36bcc --- /dev/null +++ b/Help/guide/tutorial/Step9/MathFunctions/MathFunctions.h @@ -0,0 +1 @@ +double mysqrt(double x); diff --git a/Help/guide/tutorial/Step9/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step9/MathFunctions/mysqrt.cxx new file mode 100644 index 0000000..8b82141 --- /dev/null +++ b/Help/guide/tutorial/Step9/MathFunctions/mysqrt.cxx @@ -0,0 +1,41 @@ +#include "MathFunctions.h" +#include <iostream> + +// include the generated table +#include "Table.h" + +#include <cmath> + +// a hack square root calculation using simple operations +double mysqrt(double x) +{ + if (x <= 0) { + return 0; + } + + // 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 + // use the table to help find an initial value + double result = x; + if (x >= 1 && x < 10) { + result = sqrtTable[static_cast<int>(x)]; + } + + // if we have both log and exp then use them + + // 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; + } +#endif + return result; +} diff --git a/Help/guide/tutorial/Step9/MathFunctions/mysqrt.h b/Help/guide/tutorial/Step9/MathFunctions/mysqrt.h new file mode 100644 index 0000000..e1c42ef --- /dev/null +++ b/Help/guide/tutorial/Step9/MathFunctions/mysqrt.h @@ -0,0 +1,6 @@ + +namespace mathfunctions { +namespace detail { +double mysqrt(double x); +} +} diff --git a/Help/guide/tutorial/Step9/TutorialConfig.h.in b/Help/guide/tutorial/Step9/TutorialConfig.h.in new file mode 100644 index 0000000..8cd2fc9 --- /dev/null +++ b/Help/guide/tutorial/Step9/TutorialConfig.h.in @@ -0,0 +1,3 @@ +// the configured version number +#define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@ +#define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@ diff --git a/Help/guide/tutorial/Step9/directions.txt b/Help/guide/tutorial/Step9/directions.txt new file mode 100644 index 0000000..8771637 --- /dev/null +++ b/Help/guide/tutorial/Step9/directions.txt @@ -0,0 +1,166 @@ +# 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 new file mode 100644 index 0000000..6c41859 --- /dev/null +++ b/Help/guide/tutorial/Step9/tutorial.cxx @@ -0,0 +1,33 @@ +// A simple program that computes the square root of a number +#include <cmath> +#include <iostream> +#include <sstream> +#include <string> + +#include "TutorialConfig.h" + +#ifdef USE_MYMATH +# include "MathFunctions.h" +#endif + +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 = std::stod(argv[1]); + +#ifdef USE_MYMATH + double outputValue = mysqrt(inputValue); +#else + double outputValue = sqrt(inputValue); +#endif + + std::cout << "The square root of " << inputValue << " is " << outputValue + << std::endl; + return 0; +} |