[docs] Document LLVM_ENABLE_IDE

Use some of the wording and the motivating example from r344555. The
lack of documentation was pointed out by Roman Lebedev.

Differential Revision: https://reviews.llvm.org/D58286

llvm-svn: 354167

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/docs/CMake.rst b/llvm/docs/CMake.rst
index 30fa5bc37fa..a58aa519af5 100644
--- a/llvm/docs/CMake.rst
+++ b/llvm/docs/CMake.rst
@@ -281,6 +281,15 @@ LLVM-specific variables
 **LLVM_ENABLE_EXPENSIVE_CHECKS**:BOOL
   Enable additional time/memory expensive checking. Defaults to OFF.
 
+**LLVM_ENABLE_IDE**:BOOL
+  Tell the build system that an IDE is being used. This in turn disables the
+  creation of certain convenience build system targets, such as the various
+  ``install-*`` and ``check-*`` targets, since IDEs don't always deal well with
+  a large number of targets. This is usually autodetected, but it can be
+  configured manually to explicitly control the generation of those targets. One
+  scenario where a manual override may be desirable is when using Visual Studio
+  2017's CMake integration, which would not be detected as an IDE otherwise.
+
 **LLVM_ENABLE_PIC**:BOOL
   Add the ``-fPIC`` flag to the compiler command-line, if the compiler supports
   this flag. Some systems, like Windows, do not need this flag. Defaults to ON.