add compile flags example

01-basic/F-build-type/README.adoc

@@ -10,7 +10,7 @@ toc::[]
 Introduction
 ------------
 
-CMake has a number of build in build configurations which can be used to compile
+CMake has a number of built in build configurations which can be used to compile
 your project. These specify the optimization levels and if debug information is
 to be included in the binary.
 
@@ -21,9 +21,6 @@ The levels provided are:
   * MinSizeRel - Adds `-Os -DNDEBUG`
   * RelWithDebInfo - Adds `-O2 -g -DNDEBUG` flags
 
-
-Shows a hello world example which first creates and links a static library
-
 The files in this tutorial are below:
 
 ```
@@ -78,9 +75,6 @@ if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
 endif()
 ----
 
-When creating an executable that will use your library you must tell the compiler
-about the library. This can be done using the +target_link_library()+ function.
-
 [[building-the-example]]
 Building the Example
 ~~~~~~~~~~~~~~~~~~~~

01-basic/G-compile-flags/CMakeLists.txt

@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 2.6)
+
+# Set a default C++ compile flag
+set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DEX2" CACHE STRING "Set C++ Compiler Flags" FORCE)
+
+# Set the project name
+project (compile_flags)
+
+# Add an executable
+add_executable(cmake_examples_compile_flags main.cpp)

01-basic/G-compile-flags/README.adoc

@@ -0,0 +1,122 @@
+= Compile Flags
+
+:toc:
+:toc-placement!:
+
+toc::[]
+
+
+[[intro]]
+Introduction
+------------
+
+CMake supports setting compile flags using the +CMAKE_C_FLAGS+ and +CMAKE_CXX_FLAGS+
+variables. Similarly linker flags can be set using the +CMAKE_LINKER_FLAGS+.
+
+The files in this tutorial are below:
+
+```
+$ tree
+.
+├── CMakeLists.txt
+├── main.cpp
+```
+
+  * CMakeLists.txt - Contains the CMake commands you wish to run
+  * main.cpp - The source file with main
+
+[[concepts]]
+Concepts
+~~~~~~~~
+
+[[set-cpp-flag]]
+Set C++ Flag
+^^^^^^^^^^^^
+
+Similar to the build type a C++ compiler flag can be set using the following methods.
+
+  - Using a gui tool such as ccmake / cmake-gui
+
+image::cmake-gui-set-cxx-flag.png[cmake-gui set cxx flag]
+
+  - Passing into cmake
+
+[source,cmake]
+----
+cmake .. -DCMAKE_CXX_FLAGS="-DEX3"
+----
+
+[[set-default-flag]]
+Set Default C++ Flags
+^^^^^^^^^^^^^^^^^^^^^
+
+The default `CMAKE_CXX_FLAGS` is either empty or contains the appropriate flags
+for the build type.
+
+To set additional default compile flags you can add the following to your
+top level CMakeLists.txt
+
+[source,cmake]
+----
+set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DEX2" CACHE STRING "Set C++ Compiler Flags" FORCE)
+----
+
+[NOTE]
+====
+The values `CACHE STRING "Set C++ Compiler Flags" FORCE` from the above command
+are used to force this variable to be set in the CMakeCache.txt file.
+
+For more details, see https://cmake.org/cmake/help/v3.0/command/set.html[here]
+====
+
+[[building-the-example]]
+Building the Example
+~~~~~~~~~~~~~~~~~~~~
+
+[source,bash]
+----
+$ mkdir build
+
+$ cd build/
+
+$ cmake ..
+-- The C compiler identification is GNU 4.8.4
+-- The CXX compiler identification is GNU 4.8.4
+-- Check for working C compiler: /usr/bin/cc
+-- Check for working C compiler: /usr/bin/cc -- works
+-- Detecting C compiler ABI info
+-- Detecting C compiler ABI info - done
+-- Check for working CXX compiler: /usr/bin/c++
+-- Check for working CXX compiler: /usr/bin/c++ -- works
+-- Detecting CXX compiler ABI info
+-- Detecting CXX compiler ABI info - done
+-- Configuring done
+-- Generating done
+-- Build files have been written to: /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build
+
+$ make VERBOSE=1
+/usr/bin/cmake -H/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags -B/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build --check-build-system CMakeFiles/Makefile.cmake 0
+/usr/bin/cmake -E cmake_progress_start /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build/CMakeFiles /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build/CMakeFiles/progress.marks
+make -f CMakeFiles/Makefile2 all
+make[1]: Entering directory `/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build'
+make -f CMakeFiles/cmake_examples_compile_flags.dir/build.make CMakeFiles/cmake_examples_compile_flags.dir/depend
+make[2]: Entering directory `/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build'
+cd /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build/CMakeFiles/cmake_examples_compile_flags.dir/DependInfo.cmake --color=
+Dependee "/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build/CMakeFiles/cmake_examples_compile_flags.dir/DependInfo.cmake" is newer than depender "/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build/CMakeFiles/cmake_examples_compile_flags.dir/depend.internal".
+Dependee "/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build/CMakeFiles/CMakeDirectoryInformation.cmake" is newer than depender "/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build/CMakeFiles/cmake_examples_compile_flags.dir/depend.internal".
+Scanning dependencies of target cmake_examples_compile_flags
+make[2]: Leaving directory `/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build'
+make -f CMakeFiles/cmake_examples_compile_flags.dir/build.make CMakeFiles/cmake_examples_compile_flags.dir/build
+make[2]: Entering directory `/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build'
+/usr/bin/cmake -E cmake_progress_report /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build/CMakeFiles 1
+[100%] Building CXX object CMakeFiles/cmake_examples_compile_flags.dir/main.cpp.o
+/usr/bin/c++    -DEX2   -o CMakeFiles/cmake_examples_compile_flags.dir/main.cpp.o -c /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/main.cpp
+Linking CXX executable cmake_examples_compile_flags
+/usr/bin/cmake -E cmake_link_script CMakeFiles/cmake_examples_compile_flags.dir/link.txt --verbose=1
+/usr/bin/c++    -DEX2    CMakeFiles/cmake_examples_compile_flags.dir/main.cpp.o  -o cmake_examples_compile_flags -rdynamic
+make[2]: Leaving directory `/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build'
+/usr/bin/cmake -E cmake_progress_report /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build/CMakeFiles  1
+[100%] Built target cmake_examples_compile_flags
+make[1]: Leaving directory `/home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build'
+/usr/bin/cmake -E cmake_progress_start /home/matrim/workspace/cmake-examples/01-basic/G-compile-flags/build/CMakeFiles 0
+----

01-basic/G-compile-flags/main.cpp

@@ -0,0 +1,17 @@
+#include <iostream>
+
+int main(int argc, char *argv[])
+{
+   std::cout << "Hello Compile Flags!" << std::endl;
+
+   // only print if compile flag set
+#ifdef EX2
+  std::cout << "Hello Compile Flag EX2!" << std::endl;
+#endif
+
+#ifdef EX3
+  std::cout << "Hello Compile Flag EX3!" << std::endl;
+#endif
+
+   return 0;
+}

01-basic/README.adoc

@@ -1,10 +1,14 @@
-# Basic Examples
+= Basic Examples
 
-The basic examples in this directory show how the setup a cmake project and create an executable. The examples included are
+The basic examples in this directory show how the setup a CMake project,
+set compile flags, create executables and libraries, and install them.
+
+create an executable. The examples included are
 
   - hello-cmake. A hello world example.
   - hello-headers. A slighly more complicated hello world example, with using Hello class and seperate source and include folders.
   - shared-library. An example using a shared library.
   - static-library. An example using a static library.
   - installing. Shows how to create a 'make install' target to install the binaries and libraries
-  - build-type. An example showing how to set a default build type of your project.
+  - build-type. An example showing how to set a default build type of your project.
+  - compile-flags. Shows how to set compile flags