diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst --- a/clang/docs/UsersManual.rst +++ b/clang/docs/UsersManual.rst @@ -1219,23 +1219,22 @@ Using a PCH File ^^^^^^^^^^^^^^^^ -A PCH file can then be used as a prefix header when a :option:`-include` +A PCH file can then be used as a prefix header when a :option:`-include-pch` option is passed to ``clang``: .. code-block:: console - $ clang -include test.h test.c -o test + $ clang -include-pch test.h.pch test.c -o test -The ``clang`` driver will first check if a PCH file for ``test.h`` is +The ``clang`` driver will check if the PCH file ``test.h.pch`` is available; if so, the contents of ``test.h`` (and the files it includes) -will be processed from the PCH file. Otherwise, Clang falls back to -directly processing the content of ``test.h``. This mirrors the behavior -of GCC. +will be processed from the PCH file. Otherwise, Clang will report an error. .. note:: Clang does *not* automatically use PCH files for headers that are directly - included within a source file. For example: + included within a source file or indirectly via :option:`-include`. + For example: .. code-block:: console @@ -1246,7 +1245,7 @@ In this example, ``clang`` will not automatically use the PCH file for ``test.h`` since ``test.h`` was included directly in the source file and not - specified on the command line using :option:`-include`. + specified on the command line using :option:`-include-pch`. Relocatable PCH Files ^^^^^^^^^^^^^^^^^^^^^