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.

1 files changed, 8 insertions, 1 deletions

diff --git a/Source/cmGlobalGhsMultiGenerator.cxx b/Source/cmGlobalGhsMultiGenerator.cxx
index 946ed80..f4ecff2 100644
--- a/Source/cmGlobalGhsMultiGenerator.cxx
+++ b/Source/cmGlobalGhsMultiGenerator.cxx
@@ -273,11 +273,18 @@ void cmGlobalGhsMultiGenerator::GenerateBuildCommand(
   std::vector<std::string>& makeCommand, const std::string& makeProgram,
   const std::string& /*projectName*/, const std::string& /*projectDir*/,
   const std::string& targetName, const std::string& /*config*/, bool /*fast*/,
-  bool /*verbose*/, std::vector<std::string> const& makeOptions)
+  int jobs, bool /*verbose*/, std::vector<std::string> const& makeOptions)
 {
   makeCommand.push_back(
     this->SelectMakeProgram(makeProgram, this->GetGhsBuildCommand()));
 
+  if (jobs != cmake::NO_BUILD_PARALLEL_LEVEL) {
+    makeCommand.push_back("-parallel");
+    if (jobs != cmake::DEFAULT_BUILD_PARALLEL_LEVEL) {
+      makeCommand.push_back(std::to_string(jobs));
+    }
+  }
+
   makeCommand.insert(makeCommand.end(), makeOptions.begin(),
                      makeOptions.end());
   if (!targetName.empty()) {