Allow a toolchain file to specify a generator toolset

Delay use of CMAKE_GENERATOR_TOOLSET until the CMakeSystem.cmake
file has been configured and loaded during the first project() or
enable_language() command.  This gives the toolchain file named by
CMAKE_TOOLCHAIN_FILE a chance to set CMAKE_GENERATOR_TOOLSET.  This
point is still early enough to set the generator toolset prior to
the initialization of any languages that might use the toolset.

The cmake::GeneratorToolset member variable remains an indication
of what was specified by the -T option or loaded from the cache.
It does not need to be updated based on the toolchain file setting.
The cmMakefile::TryCompile can still pass cmake::GeneratorToolset
into the inner instance because the try-compiled project will do
platform and language initialization using the CMakeSystem module
configured for the outer project.

Extend the RunCMake.GeneratorToolset test with cases that use a
toolchain file to set CMAKE_GENERATOR_TOOLSET.

1 files changed, 5 insertions, 7 deletions

diff --git a/Source/cmGlobalXCodeGenerator.cxx b/Source/cmGlobalXCodeGenerator.cxx
index 6c0eaea..87ccfbd 100644
--- a/Source/cmGlobalXCodeGenerator.cxx
+++ b/Source/cmGlobalXCodeGenerator.cxx
@@ -202,16 +202,19 @@ cmGlobalGenerator* cmGlobalXCodeGenerator::Factory
 }
 
 //----------------------------------------------------------------------------
-bool cmGlobalXCodeGenerator::SetGeneratorToolset(std::string const& ts)
+bool cmGlobalXCodeGenerator::SetGeneratorToolset(std::string const& ts,
+                                                 cmMakefile* mf)
 {
   if(this->XcodeVersion >= 30)
     {
     this->GeneratorToolset = ts;
+    mf->AddDefinition("CMAKE_XCODE_PLATFORM_TOOLSET",
+                      this->GeneratorToolset.c_str());
     return true;
     }
   else
     {
-    return cmGlobalGenerator::SetGeneratorToolset(ts);
+    return cmGlobalGenerator::SetGeneratorToolset(ts, mf);
     }
 }
 
@@ -239,11 +242,6 @@ void cmGlobalXCodeGenerator::EnableLanguage(std::vector<std::string>const&
       }
     }
   mf->AddDefinition("CMAKE_GENERATOR_NO_COMPILER_ENV", "1");
-  if(!this->GeneratorToolset.empty())
-    {
-    mf->AddDefinition("CMAKE_XCODE_PLATFORM_TOOLSET",
-                      this->GeneratorToolset.c_str());
-    }
   this->cmGlobalGenerator::EnableLanguage(lang, mf, optional);
     const char* osxArch =
       mf->GetDefinition("CMAKE_OSX_ARCHITECTURES");