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.

7 files changed, 23 insertions, 19 deletions

diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index dba4f46..bb818eb 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -76,7 +76,8 @@ cmGlobalGenerator::~cmGlobalGenerator()
     }
 }
 
-bool cmGlobalGenerator::SetGeneratorToolset(std::string const& ts)
+bool cmGlobalGenerator::SetGeneratorToolset(std::string const& ts,
+                                            cmMakefile* mf)
 {
   cmOStringStream e;
   e <<
@@ -85,8 +86,7 @@ bool cmGlobalGenerator::SetGeneratorToolset(std::string const& ts)
     "does not support toolset specification, but toolset\n"
     "  " << ts << "\n"
     "was specified.";
-  this->CMakeInstance->IssueMessage(cmake::FATAL_ERROR, e.str(),
-                                    cmListFileBacktrace());
+  mf->IssueMessage(cmake::FATAL_ERROR, e.str());
   return false;
 }
 
@@ -448,6 +448,15 @@ cmGlobalGenerator::EnableLanguage(std::vector<std::string>const& languages,
     mf->ReadListFile(0,fpath.c_str());
     }
 
+  // Tell the generator about the toolset, if any.
+  std::string toolset = mf->GetSafeDefinition("CMAKE_GENERATOR_TOOLSET");
+  if(!toolset.empty() &&
+     !this->SetGeneratorToolset(toolset, mf))
+    {
+    cmSystemTools::SetFatalErrorOccured();
+    return;
+    }
+
   // **** Load the system specific initialization if not yet loaded
   if (!mf->GetDefinition("CMAKE_SYSTEM_SPECIFIC_INITIALIZE_LOADED"))
     {
diff --git a/Source/cmGlobalGenerator.h b/Source/cmGlobalGenerator.h
index 617e708..67bd378 100644
--- a/Source/cmGlobalGenerator.h
+++ b/Source/cmGlobalGenerator.h
@@ -63,7 +63,7 @@ public:
 
   /** Set the generator-specific toolset name.  Returns true if toolset
       is supported and false otherwise.  */
-  virtual bool SetGeneratorToolset(std::string const& ts);
+  virtual bool SetGeneratorToolset(std::string const& ts, cmMakefile* mf);
 
   /**
    * Create LocalGenerators and process the CMakeLists files. This does not
diff --git a/Source/cmGlobalVisualStudio10Generator.cxx b/Source/cmGlobalVisualStudio10Generator.cxx
index a252fa0..86d0de3 100644
--- a/Source/cmGlobalVisualStudio10Generator.cxx
+++ b/Source/cmGlobalVisualStudio10Generator.cxx
@@ -116,9 +116,11 @@ cmGlobalVisualStudio10Generator::MatchesGeneratorName(
 
 //----------------------------------------------------------------------------
 bool
-cmGlobalVisualStudio10Generator::SetGeneratorToolset(std::string const& ts)
+cmGlobalVisualStudio10Generator::SetGeneratorToolset(std::string const& ts,
+                                                     cmMakefile* mf)
 {
   this->GeneratorToolset = ts;
+  this->AddVSPlatformToolsetDefinition(mf);
   return true;
 }
 
diff --git a/Source/cmGlobalVisualStudio10Generator.h b/Source/cmGlobalVisualStudio10Generator.h
index 0360fa6..b4dcc7e 100644
--- a/Source/cmGlobalVisualStudio10Generator.h
+++ b/Source/cmGlobalVisualStudio10Generator.h
@@ -31,7 +31,7 @@ public:
 
   virtual bool MatchesGeneratorName(const std::string& name) const;
 
-  virtual bool SetGeneratorToolset(std::string const& ts);
+  virtual bool SetGeneratorToolset(std::string const& ts, cmMakefile* mf);
 
   virtual void GenerateBuildCommand(
     std::vector<std::string>& makeCommand,
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");
diff --git a/Source/cmGlobalXCodeGenerator.h b/Source/cmGlobalXCodeGenerator.h
index ecbc3f9..ae23e3b 100644
--- a/Source/cmGlobalXCodeGenerator.h
+++ b/Source/cmGlobalXCodeGenerator.h
@@ -89,7 +89,7 @@ public:
       i.e. "Can I build Debug and Release in the same tree?" */
   virtual bool IsMultiConfig();
 
-  virtual bool SetGeneratorToolset(std::string const& ts);
+  virtual bool SetGeneratorToolset(std::string const& ts, cmMakefile* mf);
   void AppendFlag(std::string& flags, std::string const& flag);
 private:
   cmXCodeObject* CreateOrGetPBXGroup(cmTarget& cmtarget,
diff --git a/Source/cmake.cxx b/Source/cmake.cxx
index 9906c4b..16dc724 100644
--- a/Source/cmake.cxx
+++ b/Source/cmake.cxx
@@ -1462,11 +1462,6 @@ int cmake::ActualConfigure()
                                       "Name of generator toolset.",
                                       cmCacheManager::INTERNAL);
     }
-  if(!this->GeneratorToolset.empty() &&
-     !this->GlobalGenerator->SetGeneratorToolset(this->GeneratorToolset))
-    {
-    return -2;
-    }
 
   // reset any system configuration information, except for when we are
   // InTryCompile. With TryCompile the system info is taken from the parent's