ENH: split cmGlobalGenerator::SetLanguageEnabled() in two parts, where the

second part copies the values from the cmake variables into internal maps.
So this can now be done after the compiler-specific information has been
loaded, which can now overwrite more settings.

Alex

Modules/CMakeCCompiler.cmake.in

@@ -22,7 +22,6 @@ SET(CMAKE_C_COMPILER_ID_RUN 1)
 SET(CMAKE_C_SOURCE_FILE_EXTENSIONS c)
 SET(CMAKE_C_IGNORE_EXTENSIONS h;H;o;O;obj;OBJ;def;DEF;rc;RC)
 SET(CMAKE_C_LINKER_PREFERENCE None)
-SET(CMAKE_C_OUTPUT_EXTENSION @CMAKE_C_OUTPUT_EXTENSION@)
 
 # save the size of void* in case where cache is removed
 # and the this file is still around

Modules/CMakeCInformation.cmake

@@ -5,6 +5,14 @@
 # It also loads a system - compiler - processor (or target hardware)
 # specific file, which is mainly useful for crosscompiling and embedded systems.
 
+# some compilers use different extensions (e.g. sdcc uses .rel)
+# so set the extension here first so it can be overridden by the compiler specific file
+IF(UNIX)
+  SET(CMAKE_C_OUTPUT_EXTENSION .o)
+ELSE(UNIX)
+  SET(CMAKE_C_OUTPUT_EXTENSION .obj)
+ENDIF(UNIX)
+
 GET_FILENAME_COMPONENT(CMAKE_BASE_NAME ${CMAKE_C_COMPILER} NAME_WE)
 IF(CMAKE_COMPILER_IS_GNUCC)
   SET(CMAKE_BASE_NAME gcc)

Modules/CMakeCXXCompiler.cmake.in

@@ -22,7 +22,6 @@ SET(CMAKE_CXX_COMPILER_ID_RUN 1)
 SET(CMAKE_CXX_IGNORE_EXTENSIONS inl;h;H;o;O;obj;OBJ;def;DEF;rc;RC)
 SET(CMAKE_CXX_SOURCE_FILE_EXTENSIONS C;M;c++;cc;cpp;cxx;m;mm)
 SET(CMAKE_CXX_LINKER_PREFERENCE Prefered)
-SET(CMAKE_CXX_OUTPUT_EXTENSION @CMAKE_CXX_OUTPUT_EXTENSION@)
 
 # save the size of void* in case where cache is removed
 # and the this file is still around

Modules/CMakeCXXInformation.cmake

@@ -5,6 +5,15 @@
 # It also loads a system - compiler - processor (or target hardware)
 # specific file, which is mainly useful for crosscompiling and embedded systems.
 
+# some compilers use different extensions (e.g. sdcc uses .rel)
+# so set the extension here first so it can be overridden by the compiler specific file
+IF(UNIX)
+  SET(CMAKE_CXX_OUTPUT_EXTENSION .o)
+ELSE(UNIX)
+  SET(CMAKE_CXX_OUTPUT_EXTENSION .obj)
+ENDIF(UNIX)
+
+
 GET_FILENAME_COMPONENT(CMAKE_BASE_NAME ${CMAKE_CXX_COMPILER} NAME_WE)
 # since the gnu compiler has several names force g++
 IF(CMAKE_COMPILER_IS_GNUCXX)

Modules/CMakeDetermineCCompiler.cmake

@@ -105,17 +105,6 @@ IF (NOT _CMAKE_TOOLCHAIN_SUFFIX)
   ENDIF (COMPILER_BASENAME MATCHES "^cl(.+)\\.exe$")
 ENDIF (NOT _CMAKE_TOOLCHAIN_SUFFIX)
 
-# some exotic compilers have different extensions (e.g. sdcc uses .rel)
-# so don't overwrite it if it has been already defined by the user
-IF(NOT CMAKE_C_OUTPUT_EXTENSION)
-  IF(UNIX)
-    SET(CMAKE_C_OUTPUT_EXTENSION .o)
-  ELSE(UNIX)
-    SET(CMAKE_C_OUTPUT_EXTENSION .obj)
-  ENDIF(UNIX)
-ENDIF(NOT CMAKE_C_OUTPUT_EXTENSION)
-
-
 # Build a small source file to identify the compiler.
 IF(${CMAKE_GENERATOR} MATCHES "Visual Studio")
   SET(CMAKE_C_COMPILER_ID_RUN 1)

Modules/CMakeDetermineCXXCompiler.cmake

@@ -103,17 +103,6 @@ IF (NOT _CMAKE_TOOLCHAIN_SUFFIX)
 ENDIF (NOT _CMAKE_TOOLCHAIN_SUFFIX)
 
 
-# some exotic compilers have different extensions (e.g. sdcc uses .rel)
-# so don't overwrite it if it has been already defined by the user
-IF(NOT CMAKE_CXX_OUTPUT_EXTENSION)
-  IF(UNIX)
-    SET(CMAKE_CXX_OUTPUT_EXTENSION .o)
-  ELSE(UNIX)
-    SET(CMAKE_CXX_OUTPUT_EXTENSION .obj)
-  ENDIF(UNIX)
-ENDIF(NOT CMAKE_CXX_OUTPUT_EXTENSION)
-
-
 # This block was used before the compiler was identified by building a
 # source file.  Unless g++ crashes when building a small C++
 # executable this should no longer be needed.

Source/cmGlobalGenerator.cxx

@@ -255,6 +255,7 @@ cmGlobalGenerator::EnableLanguage(std::vector<std::string>const& languages,
     mf->ReadListFile(0,fpath.c_str());
     }
   std::map<cmStdString, bool> needTestLanguage;
+  std::map<cmStdString, bool> needSetLanguageEnabledMaps;
   // foreach language
   // load the CMakeDetermine(LANG)Compiler.cmake file to find
   // the compiler
@@ -263,6 +264,7 @@ cmGlobalGenerator::EnableLanguage(std::vector<std::string>const& languages,
       l != languages.end(); ++l)
     {
     const char* lang = l->c_str();
+    needSetLanguageEnabledMaps[lang] = false;
     if(*l == "NONE")
       {
       this->SetLanguageEnabled("NONE", mf);
@@ -296,7 +298,8 @@ cmGlobalGenerator::EnableLanguage(std::vector<std::string>const& languages,
         // if this file was found then the language was already determined
         // to be working
         needTestLanguage[lang] = false;
-        this->SetLanguageEnabled(lang, mf);
+        this->SetLanguageEnabledFlag(lang, mf);
+        needSetLanguageEnabledMaps[lang] = true;
         // this can only be called after loading CMake(LANG)Compiler.cmake
         }
       }
@@ -356,7 +359,8 @@ cmGlobalGenerator::EnableLanguage(std::vector<std::string>const& languages,
         cmSystemTools::Error("Could not find cmake module file:",
                              fpath.c_str());
         }
-      this->SetLanguageEnabled(lang, mf);
+      this->SetLanguageEnabledFlag(lang, mf);
+      needSetLanguageEnabledMaps[lang] = true;
       // this can only be called after loading CMake(LANG)Compiler.cmake
       // the language must be enabled for try compile to work, but we do
       // not know if it is a working compiler yet so set the test language
@@ -401,6 +405,11 @@ cmGlobalGenerator::EnableLanguage(std::vector<std::string>const& languages,
                              fpath.c_str());
         }
       }
+    if (needSetLanguageEnabledMaps[lang])
+      {
+      this->SetLanguageEnabledMaps(lang, mf);
+      }
+
     // Test the compiler for the language just setup
     // At this point we should have enough info for a try compile
     // which is used in the backward stuff
@@ -527,10 +536,35 @@ const char* cmGlobalGenerator::GetLanguageFromExtension(const char* ext)
 
 void cmGlobalGenerator::SetLanguageEnabled(const char* l, cmMakefile* mf)
 {
-  if(this->LanguageEnabled.count(l) > 0)
+  this->SetLanguageEnabledFlag(l, mf);
+  this->SetLanguageEnabledMaps(l, mf);
+}
+
+void cmGlobalGenerator::SetLanguageEnabledFlag(const char* l, cmMakefile* mf)
+{
+  this->LanguageEnabled[l] = true;
+}
+
+void cmGlobalGenerator::SetLanguageEnabledMaps(const char* l, cmMakefile* mf)
+{
+  // use LanguageToLinkerPreference to detect whether this functions has
+  // run before
+  if (this->LanguageToLinkerPreference.find(l) !=
+                                        this->LanguageToLinkerPreference.end())
     {
     return;
     }
+
+  std::string linkerPrefVar = std::string("CMAKE_") +
+    std::string(l) + std::string("_LINKER_PREFERENCE");
+  const char* linkerPref = mf->GetDefinition(linkerPrefVar.c_str());
+  if(!linkerPref)
+    {
+    linkerPref = "None";
+    }
+  this->LanguageToLinkerPreference[l] = linkerPref;
+
+
   std::string outputExtensionVar = std::string("CMAKE_") +
     std::string(l) + std::string("_OUTPUT_EXTENSION");
   const char* outputExtension = mf->GetDefinition(outputExtensionVar.c_str());
@@ -544,15 +578,6 @@ void cmGlobalGenerator::SetLanguageEnabled(const char* l, cmMakefile* mf)
       }
     }
 
-  std::string linkerPrefVar = std::string("CMAKE_") +
-    std::string(l) + std::string("_LINKER_PREFERENCE");
-  const char* linkerPref = mf->GetDefinition(linkerPrefVar.c_str());
-  if(!linkerPref)
-    {
-    linkerPref = "None";
-    }
-  this->LanguageToLinkerPreference[l] = linkerPref;
-
   std::string extensionsVar = std::string("CMAKE_") +
     std::string(l) + std::string("_SOURCE_FILE_EXTENSIONS");
   std::string ignoreExtensionsVar = std::string("CMAKE_") +
@@ -572,9 +597,9 @@ void cmGlobalGenerator::SetLanguageEnabled(const char* l, cmMakefile* mf)
     {
     this->IgnoreExtensions[*i] = true;
     }
-  this->LanguageEnabled[l] = true;
 
 }
+
 bool cmGlobalGenerator::IgnoreFile(const char* l)
 {
   if(this->GetLanguageFromExtension(l))

Source/cmGlobalGenerator.h

@@ -208,6 +208,9 @@ public:
 
   const std::map<cmStdString, std::vector<cmLocalGenerator*> >& GetProjectMap() const {return this->ProjectMap;}
 protected:
+  void SetLanguageEnabledFlag(const char* l, cmMakefile* mf);
+  void SetLanguageEnabledMaps(const char* l, cmMakefile* mf);
+
   // Fill the ProjectMap, this must be called after LocalGenerators 
   // has been populated.
   void FillProjectMap();