From 41d802b2b5ffc126f745d9ce417a24324b3cefd0 Mon Sep 17 00:00:00 2001 From: George Karpenkov Date: Mon, 10 Jul 2017 18:56:51 +0000 Subject: [PATCH] [docs] Remove obsolete section in CMake documentation. Differential Revision: https://reviews.llvm.org/D35023 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307568 91177308-0d34-0410-b5e6-96231b3b80d8 --- docs/CMakePrimer.rst | 27 --------------------------- 1 file changed, 27 deletions(-) diff --git a/docs/CMakePrimer.rst b/docs/CMakePrimer.rst index 1e3a09e4d98..c29d627ee62 100644 --- a/docs/CMakePrimer.rst +++ b/docs/CMakePrimer.rst @@ -112,33 +112,6 @@ In this example the ``extra_sources`` variable is only defined if you're targeting an Apple platform. For all other targets the ``extra_sources`` will be evaluated as empty before add_executable is given its arguments. -One big "Gotcha" with variable dereferencing is that ``if`` commands implicitly -dereference values. This has some unexpected results. For example: - -.. code-block:: cmake - - if("${SOME_VAR}" STREQUAL "MSVC") - -In this code sample MSVC will be implicitly dereferenced, which will result in -the if command comparing the value of the dereferenced variables ``SOME_VAR`` -and ``MSVC``. A common workaround to this solution is to prepend strings being -compared with an ``x``. - -.. code-block:: cmake - - if("x${SOME_VAR}" STREQUAL "xMSVC") - -This works because while ``MSVC`` is a defined variable, ``xMSVC`` is not. This -pattern is uncommon, but it does occur in LLVM's CMake scripts. - -.. note:: - - Once the LLVM project upgrades its minimum CMake version to 3.1 or later we - can prevent this behavior by setting CMP0054 to new. For more information on - CMake policies please see the cmake-policies manpage or the `cmake-policies - online documentation - `_. - Lists ----- -- 2.40.0