Export: Use the CMAKE_DEVEL_VERSION macro for build-export files.

Move the macro definition to the cmExportBuildFileGenerator.h header
to share it.

Source/cmExportBuildFileGenerator.cxx

@@ -52,7 +52,7 @@ bool cmExportBuildFileGenerator::GenerateMainFile(std::ostream& os)
       }
     if (te->GetType() == cmTarget::INTERFACE_LIBRARY)
       {
-      this->GenerateRequiredCMakeVersion(os, "2.8.12.20131007"); // 2.8.13
+      this->GenerateRequiredCMakeVersion(os, DEVEL_CMAKE_VERSION(3, 0, 0));
       }
     }
 

Source/cmExportFileGenerator.h

@@ -15,6 +15,21 @@
 #include "cmCommand.h"
 #include "cmGeneratorExpression.h"
 
+#include "cmVersionMacros.h"
+#include "cmVersion.h"
+
+#define STRINGIFY_HELPER(X) #X
+#define STRINGIFY(X) STRINGIFY_HELPER(X)
+
+#define DEVEL_CMAKE_VERSION(maj, min, patch) \
+  (CMake_VERSION_ENCODE(maj, min, patch) > \
+   CMake_VERSION_ENCODE(CMake_VERSION_MAJOR, CMake_VERSION_MINOR, \
+                        CMake_VERSION_PATCH) \
+  ) ? \
+    STRINGIFY(CMake_VERSION_MAJOR) "." STRINGIFY(CMake_VERSION_MINOR) "." \
+    STRINGIFY(CMake_VERSION_PATCH) "." STRINGIFY(CMake_VERSION_TWEAK) \
+  : #maj "." #min "." #patch
+
 class cmTargetExport;
 
 /** \class cmExportFileGenerator

Source/cmExportInstallFileGenerator.cxx

@@ -19,20 +19,6 @@
 #include "cmInstallExportGenerator.h"
 #include "cmInstallTargetGenerator.h"
 #include "cmTargetExport.h"
-#include "cmVersionMacros.h"
-#include "cmVersion.h"
-
-#define STRINGIFY_HELPER(X) #X
-#define STRINGIFY(X) STRINGIFY_HELPER(X)
-
-#define DEVEL_CMAKE_VERSION(maj, min, patch) \
-  (CMake_VERSION_ENCODE(maj, min, patch) > \
-   CMake_VERSION_ENCODE(CMake_VERSION_MAJOR, CMake_VERSION_MINOR, \
-                        CMake_VERSION_PATCH) \
-  ) ? \
-    STRINGIFY(CMake_VERSION_MAJOR) "." STRINGIFY(CMake_VERSION_MINOR) "." \
-    STRINGIFY(CMake_VERSION_PATCH) "." STRINGIFY(CMake_VERSION_TWEAK) \
-  : #maj "." #min "." #patch
 
 //----------------------------------------------------------------------------
 cmExportInstallFileGenerator