cmGlobalGenerator: Call SetGeneratorToolset even for empty toolset

Move handling of an empty toolset name into the implementation of the
method.  This simplifies the VS 10 implementation of default toolset
selection because it has one code path that is always called.

Source/cmGlobalGenerator.cxx

@@ -79,15 +79,22 @@ cmGlobalGenerator::~cmGlobalGenerator()
 bool cmGlobalGenerator::SetGeneratorToolset(std::string const& ts,
                                             cmMakefile* mf)
 {
-  cmOStringStream e;
-  e <<
-    "Generator\n"
-    "  " << this->GetName() << "\n"
-    "does not support toolset specification, but toolset\n"
-    "  " << ts << "\n"
-    "was specified.";
-  mf->IssueMessage(cmake::FATAL_ERROR, e.str());
-  return false;
+  if(ts.empty())
+    {
+    return true;
+    }
+  else
+    {
+    cmOStringStream e;
+    e <<
+      "Generator\n"
+      "  " << this->GetName() << "\n"
+      "does not support toolset specification, but toolset\n"
+      "  " << ts << "\n"
+      "was specified.";
+    mf->IssueMessage(cmake::FATAL_ERROR, e.str());
+    return false;
+    }
 }
 
 std::string cmGlobalGenerator::SelectMakeProgram(
@@ -454,8 +461,7 @@ cmGlobalGenerator::EnableLanguage(std::vector<std::string>const& languages,
 
   // Tell the generator about the toolset, if any.
   std::string toolset = mf->GetSafeDefinition("CMAKE_GENERATOR_TOOLSET");
-  if(!toolset.empty() &&
-     !this->SetGeneratorToolset(toolset, mf))
+  if(!this->SetGeneratorToolset(toolset, mf))
     {
     cmSystemTools::SetFatalErrorOccured();
     return;

Source/cmGlobalVisualStudio10Generator.cxx

@@ -121,7 +121,10 @@ cmGlobalVisualStudio10Generator::SetGeneratorToolset(std::string const& ts,
                                                      cmMakefile* mf)
 {
   this->GeneratorToolset = ts;
-  this->AddVSPlatformToolsetDefinition(mf);
+  if(const char* toolset = this->GetPlatformToolset())
+    {
+    mf->AddDefinition("CMAKE_VS_PLATFORM_TOOLSET", toolset);
+    }
   return true;
 }
 
@@ -142,7 +145,6 @@ bool cmGlobalVisualStudio10Generator::SetSystemName(std::string const& s,
       return false;
       }
     }
-  this->AddVSPlatformToolsetDefinition(mf);
   return this->cmGlobalVisualStudio8Generator::SetSystemName(s, mf);
 }
 
@@ -186,16 +188,6 @@ bool cmGlobalVisualStudio10Generator::InitializeWindowsStore(cmMakefile* mf)
   return false;
 }
 
-//----------------------------------------------------------------------------
-void cmGlobalVisualStudio10Generator
-::AddVSPlatformToolsetDefinition(cmMakefile* mf) const
-{
-  if(const char* toolset = this->GetPlatformToolset())
-    {
-    mf->AddDefinition("CMAKE_VS_PLATFORM_TOOLSET", toolset);
-    }
-}
-
 //----------------------------------------------------------------------------
 void cmGlobalVisualStudio10Generator::WriteSLNHeader(std::ostream& fout)
 {

Source/cmGlobalVisualStudio10Generator.h

@@ -140,6 +140,5 @@ private:
   virtual std::string FindMSBuildCommand();
   virtual std::string FindDevEnvCommand();
   virtual std::string GetVSMakeProgram() { return this->GetMSBuildCommand(); }
-  void AddVSPlatformToolsetDefinition(cmMakefile* mf) const;
 };
 #endif

Source/cmGlobalXCodeGenerator.cxx

@@ -208,8 +208,11 @@ bool cmGlobalXCodeGenerator::SetGeneratorToolset(std::string const& ts,
   if(this->XcodeVersion >= 30)
     {
     this->GeneratorToolset = ts;
-    mf->AddDefinition("CMAKE_XCODE_PLATFORM_TOOLSET",
-                      this->GeneratorToolset.c_str());
+    if(!this->GeneratorToolset.empty())
+      {
+      mf->AddDefinition("CMAKE_XCODE_PLATFORM_TOOLSET",
+                        this->GeneratorToolset.c_str());
+      }
     return true;
     }
   else