Xcode: Implement generator toolset selection (#9831, #13802)

Implement generator toolset selection (cmake -T) for Xcode > 2.0 by
adding the GCC_VERSION build setting to project files.

Modules/CMakeDetermineCompilerId.cmake

@@ -177,6 +177,11 @@ Id flags: ${testflags}
     set(id_type ${CMAKE_${lang}_COMPILER_XCODE_TYPE})
     set(id_dir ${CMAKE_${lang}_COMPILER_ID_DIR})
     get_filename_component(id_src "${src}" NAME)
+    if(CMAKE_XCODE_PLATFORM_TOOLSET)
+      set(id_toolset "GCC_VERSION = ${CMAKE_XCODE_PLATFORM_TOOLSET};")
+    else()
+      set(id_toolset "")
+    endif()
     if(NOT ${XCODE_VERSION} VERSION_LESS 3)
       set(v 3)
       set(ext xcodeproj)

Modules/CompilerId/Xcode-3.pbxproj.in

@@ -83,6 +83,7 @@
 				ONLY_ACTIVE_ARCH = YES;
 				CONFIGURATION_BUILD_DIR = "$(BUILD_DIR)";
 				SYMROOT = .;
+				@id_toolset@
 			};
 			name = Debug;
 		};

Source/cmDocumentVariables.cxx

@@ -302,6 +302,15 @@ void cmDocumentVariables::DefineVariables(cmake* cm)
      "CMake provides the name of the chosen toolset in this variable."
      ,false,
      "Variables that Provide Information");
+  cm->DefineProperty
+    ("CMAKE_XCODE_PLATFORM_TOOLSET", cmProperty::VARIABLE,
+     "Xcode compiler selection.",
+     "Xcode supports selection of a compiler from one of the installed "
+     "toolsets.  "
+     "CMake provides the name of the chosen toolset in this variable, "
+     "if any is explicitly selected (e.g. via the cmake -T option)."
+     ,false,
+     "Variables that Provide Information");
   cm->DefineProperty
     ("CMAKE_MINOR_VERSION", cmProperty::VARIABLE,
      "The Minor version of cmake (i.e. the 4 in X.4.X).",

Source/cmGlobalXCodeGenerator.cxx

@@ -200,6 +200,20 @@ cmGlobalGenerator* cmGlobalXCodeGenerator::Factory
 #endif
 }
 
+//----------------------------------------------------------------------------
+bool cmGlobalXCodeGenerator::SetGeneratorToolset(std::string const& ts)
+{
+  if(this->XcodeVersion >= 30)
+    {
+    this->PlatformToolset = ts;
+    return true;
+    }
+  else
+    {
+    return cmGlobalGenerator::SetGeneratorToolset(ts);
+    }
+}
+
 //----------------------------------------------------------------------------
 void cmGlobalXCodeGenerator::EnableLanguage(std::vector<std::string>const&
                                             lang,
@@ -226,6 +240,11 @@ void cmGlobalXCodeGenerator::EnableLanguage(std::vector<std::string>const&
   mf->AddDefinition("CMAKE_GENERATOR_CC", "gcc");
   mf->AddDefinition("CMAKE_GENERATOR_CXX", "g++");
   mf->AddDefinition("CMAKE_GENERATOR_NO_COMPILER_ENV", "1");
+  if(!this->PlatformToolset.empty())
+    {
+    mf->AddDefinition("CMAKE_XCODE_PLATFORM_TOOLSET",
+                      this->PlatformToolset.c_str());
+    }
   this->cmGlobalGenerator::EnableLanguage(lang, mf, optional);
     const char* osxArch =
       mf->GetDefinition("CMAKE_OSX_ARCHITECTURES");
@@ -3163,6 +3182,11 @@ void cmGlobalXCodeGenerator
     buildSettings->AddAttribute("MACOSX_DEPLOYMENT_TARGET",
                                 this->CreateString(deploymentTarget));
     }
+  if(!this->PlatformToolset.empty())
+    {
+    buildSettings->AddAttribute("GCC_VERSION",
+      this->CreateString(this->PlatformToolset.c_str()));
+    }
 
   // Put this last so it can override existing settings
   // Convert "CMAKE_XCODE_ATTRIBUTE_*" variables directly.

Source/cmGlobalXCodeGenerator.h

@@ -83,6 +83,7 @@ public:
       i.e. "Can I build Debug and Release in the same tree?" */
   virtual bool IsMultiConfig();
 
+  virtual bool SetGeneratorToolset(std::string const& ts);
 private:
   cmXCodeObject* CreateOrGetPBXGroup(cmTarget& cmtarget,
                                      cmSourceGroup* sg);
@@ -236,6 +237,7 @@ private:
   std::map<cmStdString, cmXCodeObject* > TargetGroup;
   std::map<cmStdString, cmXCodeObject* > FileRefs;
   std::vector<std::string> Architectures;
+  std::string PlatformToolset;
 };
 
 #endif

Source/cmake.h

@@ -542,6 +542,7 @@ private:
    "native build system to choose a compiler.  " \
    "This is supported only on specific generators:\n" \
    "  Visual Studio >= 10\n" \
+   "  Xcode >= 3.0\n" \
    "See native build system documentation for allowed toolset names."}, \
   {"-Wno-dev", "Suppress developer warnings.",\
    "Suppress warnings that are meant for the author"\

Tests/RunCMake/CMakeLists.txt

@@ -41,10 +41,15 @@ macro(add_RunCMake_test test)
     -DRunCMake_GENERATOR=${CMAKE_TEST_GENERATOR}
     -DRunCMake_SOURCE_DIR=${CMAKE_CURRENT_SOURCE_DIR}/${test}
     -DRunCMake_BINARY_DIR=${CMAKE_CURRENT_BINARY_DIR}/${test}
+    ${${test}_ARGS}
     -P "${CMAKE_CURRENT_SOURCE_DIR}/${test}/RunCMakeTest.cmake"
     )
 endmacro()
 
+if(XCODE_VERSION AND "${XCODE_VERSION}" VERSION_LESS 3)
+  set(GeneratorToolset_ARGS -DXCODE_BELOW_3=1)
+endif()
+
 add_RunCMake_test(CMP0019)
 add_RunCMake_test(GeneratorExpression)
 add_RunCMake_test(GeneratorToolset)

Tests/RunCMake/GeneratorToolset/RunCMakeTest.cmake

@@ -2,7 +2,7 @@ include(RunCMake)
 
 run_cmake(NoToolset)
 
-if("${RunCMake_GENERATOR}" MATCHES "Visual Studio 1[01]")
+if("${RunCMake_GENERATOR}" MATCHES "Visual Studio 1[01]|Xcode" AND NOT XCODE_BELOW_3)
   set(RunCMake_TEST_OPTIONS -T "Test Toolset")
   run_cmake(TestToolset)
   unset(RunCMake_TEST_OPTIONS)