[clang] [Clang] [Docs] Add some CMake example code for linking against libclang (PR #166268)

[via cfe-commits]

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@@ -57,6 +58,22 @@ Code example
     CXCursor cursor = clang_getTranslationUnitCursor(unit); //Obtain a cursor at the root of the translation unit
   }
 
+.. code-block:: cmake
+
+  # CMakeLists.txt
+  cmake_minimum_required(VERSION 3.20)
+  project(my_clang_tool VERSION 0.1.0)
+
+  # This will find the default system installation of Clang; if you want to
+  # use a different build of clang, pass -DClang_DIR=/foobar/lib/cmake/clang
+  # to the CMake configure command, where /foobar is the build directory where
+  # you built Clang.
+  find_package(Clang CONFIG REQUIRED)
+
+  add_executable(my_clang_tool main.cpp)
+  target_include_directories(my_clang_tool PRIVATE ${CLANG_INCLUDE_DIRS})
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Sirraide wrote:

Yeah, normally `target_link_libraries` should set the include directories properly, but I distinctly recall running into horrible crashes on several occasions whenever I forgot this step because it’d find my system clang headers but link against my more up-to-date local clang build, which of course didn’t end well, so I made sure to include that here.

https://github.com/llvm/llvm-project/pull/166268