[clang] [Sanitizer][Docs] Improve docs on building Asan (PR #68636)

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llvmbot wrote:


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@llvm/pr-subscribers-clang

<details>
<summary>Changes</summary>

Currently the documentation for building Asan doesn't specify that compiler-rt needs to be built as well. In addition, there's no minimal example for the LLVM CMake configuration. This patch addresses both of these issues.

The lack of specification about building compiler-rt has shown up on Discourse (e.g., https://discourse.llvm.org/t/enabling-address-sanitizer/73940/2).

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Full diff: https://github.com/llvm/llvm-project/pull/68636.diff


1 Files Affected:

- (modified) clang/docs/AddressSanitizer.rst (+10-1) 


``````````diff
diff --git a/clang/docs/AddressSanitizer.rst b/clang/docs/AddressSanitizer.rst
index 37f34cb0cc9936d..94ff3404cba6024 100644
--- a/clang/docs/AddressSanitizer.rst
+++ b/clang/docs/AddressSanitizer.rst
@@ -26,7 +26,16 @@ Typical slowdown introduced by AddressSanitizer is **2x**.
 How to build
 ============
 
-Build LLVM/Clang with `CMake <https://llvm.org/docs/CMake.html>`_.
+Build LLVM/Clang with `CMake <https://llvm.org/docs/CMake.html>` and enable
+the ``compiler-rt`` runtime. An example CMake configuration that will allow
+for the use/testing of AddressSanitizer:
+
+.. code-block:: console
+
+   cmake -DCMAKE_BUILD_TYPE=Release \
+     -DLLVM_ENABLE_PROJECTS="clang" \
+     -DLLVM_ENABLE_RUNTIMES="compiler-rt" \
+     ../llvm
 
 Usage
 =====

``````````

</details>


https://github.com/llvm/llvm-project/pull/68636