Ninja Multi-Config: Make cross-config building opt-in

Many users will want to use the Ninja Multi-Config generator like a
traditional Visual Studio-style multi-config generator, which doesn't
mix configurations - custom commands are built using target executables
of the same configuration the command is for. We do not want to force
these people to generate an N*N build matrix when they only need N*1,
especially if they have lots of targets. Add a new variable,
CMAKE_NINJA_CROSS_CONFIG_ENABLE, to opt-in to the cross-config build
matrix.

1 files changed, 12 insertions, 2 deletions

diff --git a/Source/cmNinjaNormalTargetGenerator.cxx b/Source/cmNinjaNormalTargetGenerator.cxx
index 987f241..8dbe1a3 100644
--- a/Source/cmNinjaNormalTargetGenerator.cxx
+++ b/Source/cmNinjaNormalTargetGenerator.cxx
@@ -72,6 +72,10 @@ void cmNinjaNormalTargetGenerator::Generate(const std::string& config)
   // Write the build statements
   bool firstForConfig = true;
   for (auto const& fileConfig : this->GetConfigNames()) {
+    if (fileConfig != config &&
+        !this->GetGlobalGenerator()->EnableCrossConfigBuild()) {
+      continue;
+    }
     this->WriteObjectBuildStatements(config, fileConfig, firstForConfig);
     firstForConfig = false;
   }
@@ -84,12 +88,18 @@ void cmNinjaNormalTargetGenerator::Generate(const std::string& config)
     this->WriteDeviceLinkStatement(config);
     firstForConfig = true;
     for (auto const& fileConfig : this->GetConfigNames()) {
+      if (fileConfig != config &&
+          !this->GetGlobalGenerator()->EnableCrossConfigBuild()) {
+        continue;
+      }
       this->WriteLinkStatement(config, fileConfig, firstForConfig);
       firstForConfig = false;
     }
   }
-  this->GetGlobalGenerator()->AddTargetAlias(
-    this->GetTargetName(), this->GetGeneratorTarget(), "all");
+  if (this->GetGlobalGenerator()->EnableCrossConfigBuild()) {
+    this->GetGlobalGenerator()->AddTargetAlias(
+      this->GetTargetName(), this->GetGeneratorTarget(), "all");
+  }
 
   // Find ADDITIONAL_CLEAN_FILES
   this->AdditionalCleanFiles(config);