cmake: Add options for parallel builds to --build mode

While we already support `cmake --build . -- -j`, the options after `--`
are specific to the native build tool.  Add new options `--parallel
[<N>]` and `-j [<N>]` to abstract this and map to the proper option
for the native build tool.

2 files changed, 8 insertions, 0 deletions

diff --git a/Help/manual/cmake-env-variables.7.rst b/Help/manual/cmake-env-variables.7.rst
index 2d8869f..2d17bb5 100644
--- a/Help/manual/cmake-env-variables.7.rst
+++ b/Help/manual/cmake-env-variables.7.rst
@@ -13,6 +13,7 @@ Environment Variables that Control the Build
 .. toctree::
    :maxdepth: 1
 
+   /envvar/CMAKE_BUILD_PARALLEL_LEVEL
    /envvar/CMAKE_CONFIG_TYPE
    /envvar/CMAKE_MSVCIDE_RUN_PATH
    /envvar/CMAKE_OSX_ARCHITECTURES
diff --git a/Help/manual/cmake.1.rst b/Help/manual/cmake.1.rst
index 577d321..177acd4 100644
--- a/Help/manual/cmake.1.rst
+++ b/Help/manual/cmake.1.rst
@@ -159,6 +159,13 @@ following options:
 ``--build <dir>``
   Project binary directory to be built.  This is required and must be first.
 
+``-j [<jobs>], --parallel [<jobs>]``
+  The maximum number of concurrent processes to use when building.
+  If ``<jobs>`` is omitted the native build tool's default number is used.
+
+  The :envvar:`CMAKE_BUILD_PARALLEL_LEVEL` environment variable, if set,
+  specifies a default parallel level when this option is not given.
+
 ``--target <tgt>``
   Build ``<tgt>`` instead of default targets.  May only be specified once.