Tutorial: Move step 10 to step 4

Shifts steps 4-9 to 5-10.

Help/guide/tutorial/Step10/CMakeLists.txt

@@ -1,29 +1,37 @@
-cmake_minimum_required(VERSION 3.10)
+cmake_minimum_required(VERSION 3.15)
 
 # set the project name and version
 project(Tutorial VERSION 1.0)
 
 # specify the C++ standard
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+add_library(tutorial_compiler_flags INTERFACE)
+target_compile_features(tutorial_compiler_flags INTERFACE cxx_std_11)
 
-# 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 "${PROJECT_BINARY_DIR}")
+# add compiler warning flags just when building this project via
+# the BUILD_INTERFACE genex
+set(gcc_like_cxx "$<COMPILE_LANG_AND_ID:CXX,ARMClang,AppleClang,Clang,GNU,LCC>")
+set(msvc_cxx "$<COMPILE_LANG_AND_ID:CXX,MSVC>")
+target_compile_options(tutorial_compiler_flags INTERFACE
+  "$<${gcc_like_cxx}:$<BUILD_INTERFACE:-Wall;-Wextra;-Wshadow;-Wformat=2;-Wunused>>"
+  "$<${msvc_cxx}:$<BUILD_INTERFACE:-W3>>"
+)
 
-option(BUILD_SHARED_LIBS "Build using shared libraries" ON)
+# 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 a header file to pass some of the CMake settings
+# to the source code
 configure_file(TutorialConfig.h.in TutorialConfig.h)
 
 # add the MathFunctions library
-add_subdirectory(MathFunctions)
+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 MathFunctions)
+target_link_libraries(Tutorial PUBLIC ${EXTRA_LIBS} tutorial_compiler_flags)
 
 # add the binary tree to the search path for include files
 # so that we will find TutorialConfig.h
@@ -66,6 +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}")

Help/guide/tutorial/Step10/License.txt

@@ -1,2 +1,2 @@
 This is the open source License.txt file introduced in
-CMake/Tutorial/Step7...
+CMake/Tutorial/Step9...

Help/guide/tutorial/Step10/MathFunctions/CMakeLists.txt

@@ -1,55 +1,30 @@
-# add the library that runs
-add_library(MathFunctions MathFunctions.cxx)
+# 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}
-                           )
+          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
+          PRIVATE   ${CMAKE_CURRENT_BINARY_DIR}
+          )
 
-# should we use our own math functions
-option(USE_MYMATH "Use tutorial provided math implementation" ON)
-if(USE_MYMATH)
-
-  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
-
-  # 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}
-                             )
-
-  # state that SqrtLibrary need PIC when the default is shared libraries
-  set_target_properties(SqrtLibrary PROPERTIES
-                        POSITION_INDEPENDENT_CODE ${BUILD_SHARED_LIBS}
-                        )
-
-  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")
+target_link_libraries(MathFunctions tutorial_compiler_flags)
 
 # install rules
-set(installable_libs MathFunctions)
-if(TARGET SqrtLibrary)
-  list(APPEND installable_libs SqrtLibrary)
-endif()
+set(installable_libs MathFunctions tutorial_compiler_flags)
 install(TARGETS ${installable_libs} DESTINATION lib)
 install(FILES MathFunctions.h DESTINATION include)

Help/guide/tutorial/Step10/MathFunctions/MathFunctions.h

@@ -1,14 +1 @@
-
-#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);
-}
+double mysqrt(double x);

Help/guide/tutorial/Step10/MathFunctions/mysqrt.cxx

@@ -5,8 +5,6 @@
 // include the generated table
 #include "Table.h"
 
-namespace mathfunctions {
-namespace detail {
 // a hack square root calculation using simple operations
 double mysqrt(double x)
 {
@@ -33,5 +31,3 @@ double mysqrt(double x)
 
   return result;
 }
-}
-}

Help/guide/tutorial/Step10/TutorialConfig.h.in

@@ -1,3 +1,4 @@
 // the configured options and settings for Tutorial
 #define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
 #define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@
+#cmakedefine USE_MYMATH

Help/guide/tutorial/Step10/tutorial.cxx

@@ -1,11 +1,15 @@
 // A simple program that computes the square root of a number
+#include <cmath>
 #include <iostream>
-#include <sstream>
 #include <string>
 
-#include "MathFunctions.h"
 #include "TutorialConfig.h"
 
+// should we include the MathFunctions header?
+#ifdef USE_MYMATH
+#  include "MathFunctions.h"
+#endif
+
 int main(int argc, char* argv[])
 {
   if (argc < 2) {
@@ -19,7 +23,12 @@ int main(int argc, char* argv[])
   // convert input to double
   const double inputValue = std::stod(argv[1]);
 
-  const double outputValue = mathfunctions::sqrt(inputValue);
+  // which square root function should we use?
+#ifdef USE_MYMATH
+  const double outputValue = mysqrt(inputValue);
+#else
+  const double outputValue = sqrt(inputValue);
+#endif
 
   std::cout << "The square root of " << inputValue << " is " << outputValue
             << std::endl;