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@@ -15,8 +15,57 @@ vlink="#000000" alink="#000000">
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<td width="550" valign="top" bgcolor="#FFFFFF">
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<div align="left">
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<font size=5>The following example </font> demonstrates some key ideas
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- of CMake.
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+ of CMake. (You may wish to download this
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+ <a href="/CMake/HTML/cmakeExample.tar.gz">example code</a> and try it
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+ out for yourself.)
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+ <p>
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+ There are three directories involved. The top level directory has two
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+ subdirectories called ./Demo and ./Hello. In the directory ./Hello, a
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+ library is built. In the directory ./Demo, an executable is built by
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+ linking to the library. A total of three CMakeList.txt files are
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+ created: one for each directory.
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+ <p>
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+ The first, top-level directory contains the following CMakeLists.txt file.
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+ <pre>
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+# The name of our project is "HELLO". CMakeLists files in this project can
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+# refer to the root source directory of the project as ${HELLO_SOURCE_DIR} and
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+# to the root binary directory of the project as ${HELLO_BINARY_DIR}.
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+PROJECT(HELLO)
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+# Recurse into the "Hello" and "Demo" subdirectories. This does not actually
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+# cause another cmake executable to run. The same process will walk through
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+# the project's entire directory structure.
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+SUBDIRS(Hello Demo)
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+ </pre>
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+ Then for each subdirectory listed in the SUBDIRS command, CMakeLists.txt
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+ files are created. In the ./Hello directory, the following CMakeLists.txt
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+ file is created:
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+ <pre>
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+# Create a library called "Hello" which includes the source file "hello.cxx".
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+# The extension is already found. Any number of sources could be listed here.
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+ADD_LIBRARY(Hello hello)
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+ </pre>
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+ Finally, in the ./Demo directory, the third and final CMakeLists.txt file
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+ is created:
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+ <pre>
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+# Make sure the compiler can find include files from our Hello library.
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+INCLUDE_DIRECTORIES(${HELLO_SOURCE_DIR}/Hello)
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+
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+# Make sure the linker can find the Hello library once it is built.
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+LINK_DIRECTORIES(${HELLO_BINARY_DIR}/Hello)
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+
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+# Add executable called "helloDemo" that is built from the source files
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+# "demo.cxx" and "demo_b.cxx". The extensions are automatically found.
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+ADD_EXECUTABLE(helloDemo demo demo_b)
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+
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+# Link the executable to the Hello library.
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+TARGET_LINK_LIBRARIES(helloDemo Hello)
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+ </pre>
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+ CMake when executed in the top-level directory will process the
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+ CMakeLists.txt file and then descend into the listed subdirectories.
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+ Variables, include paths, library paths, etc. are inherited. Depending
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+ on the system, makefiles (Unix) or workspaces/projects (MSVC) will be
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+ built. These can then be used in the usual way to build the code.
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</div>
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</td>
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</tr>
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Will Schroeder
