[libc][docs] Add a build and test document.

2 files changed, 44 insertions, 0 deletions

diff --git a/libc/docs/build_and_test.rst b/libc/docs/build_and_test.rst
new file mode 100644
index 000000000000..423481ecc3a5
--- /dev/null
+++ b/libc/docs/build_and_test.rst
@@ -0,0 +1,43 @@
+.. _build_and_test:
+
+=============================
+Building and Testing the libc
+=============================
+
+The libc can be built and tested in two different modes:
+
+#. **The overlay mode** - In this mode, one uses the static archive from LLVM's
+   libc along with the system libc. See :ref:`overlay_mode` for more details
+   on building and using the libc in this mode. You can only run the libc
+   unittests in this mode. To run them, one simply does:
+
+   .. code-block:: sh
+
+     $> ninja check-libc
+
+   Note that, unittests for only those functions which are part of the overlay
+   static archive will be run with the above command.
+
+#. **The full build mode** - In this mode, the libc is used as the only libc
+   for the user's application. See :ref:`fullbuild_mode` for more details on
+   building and using the libc in this mode. Once configured for a full libc
+   build, you can run three kinds of tests:
+
+   #. Unit tests - You can run unittests by the command:
+
+      .. code-block:: sh
+
+        $> ninja check-libc
+
+   #. Integration tests - You can run integration tests by the command:
+
+      .. code-block:: sh
+
+        $> ninja libc-integration-tests
+
+   #. API verification test - See :ref:`api_test` for more information about
+      the API test. It can be run by the command:
+
+      .. code-block:: sh
+
+        $> ninja libc-api-test
diff --git a/libc/docs/index.rst b/libc/docs/index.rst
index e99ebafe274e..c298f00c1e99 100644
--- a/libc/docs/index.rst
+++ b/libc/docs/index.rst
@@ -68,6 +68,7 @@ stages there is no ABI stability in any form.
    :maxdepth: 1
    :caption: Development
 
+   build_and_test
    developer_guides
    porting
    contributing