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| author | George Karpenkov <ekarpenkov@apple.com> | 2017-07-10 18:56:51 +0000 |
|---|---|---|
| committer | George Karpenkov <ekarpenkov@apple.com> | 2017-07-10 18:56:51 +0000 |
| commit | 41d802b2b5ffc126f745d9ce417a24324b3cefd0 (patch) | |
| tree | 10975ac65d589a140616e1b1e3e86797cc2ed5fc | |
| parent | 33287d8a695fb3f0a4eef7c8ee6a9f62400c3c1a (diff) | |
[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
| -rw-r--r-- | docs/CMakePrimer.rst | 27 |
1 files changed, 0 insertions, 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 - <https://cmake.org/cmake/help/v3.4/manual/cmake-policies.7.html>`_. - Lists ----- |