Merge topic 'export-at-generate-time'

a4263c9 export(): Handle multiple dependent export sets.
66b290e export(): Process the export() command at generate time.
5fe5c32 export(): Set a Makefile on the cmExportBuildFileGenerator.
e383555 cmExportInstallFileGenerator: Fix comment to match reality.

13 files changed, 209 insertions, 111 deletions

diff --git a/Source/cmExportBuildFileGenerator.cxx b/Source/cmExportBuildFileGenerator.cxx
index 243e5ce..50835e2 100644
--- a/Source/cmExportBuildFileGenerator.cxx
+++ b/Source/cmExportBuildFileGenerator.cxx
@@ -11,40 +11,38 @@
 ============================================================================*/
 #include "cmExportBuildFileGenerator.h"
 
-#include "cmExportCommand.h"
+#include "cmLocalGenerator.h"
+#include "cmGlobalGenerator.h"
 
 //----------------------------------------------------------------------------
 cmExportBuildFileGenerator::cmExportBuildFileGenerator()
 {
-  this->ExportCommand = 0;
+  this->Makefile = 0;
 }
 
 //----------------------------------------------------------------------------
 bool cmExportBuildFileGenerator::GenerateMainFile(std::ostream& os)
 {
-  std::vector<cmTarget*> allTargets;
   {
   std::string expectedTargets;
   std::string sep;
-  for(std::vector<cmTarget*>::const_iterator
-        tei = this->Exports->begin();
-      tei != this->Exports->end(); ++tei)
+  for(std::vector<std::string>::const_iterator
+        tei = this->Targets.begin();
+      tei != this->Targets.end(); ++tei)
     {
-    expectedTargets += sep + this->Namespace + (*tei)->GetExportName();
+    cmTarget *te = this->Makefile->FindTargetToUse(tei->c_str());
+    expectedTargets += sep + this->Namespace + te->GetExportName();
     sep = " ";
-    cmTarget* te = *tei;
     if(this->ExportedTargets.insert(te).second)
       {
-      allTargets.push_back(te);
+      this->Exports.push_back(te);
       }
     else
       {
-      if(this->ExportCommand && this->ExportCommand->ErrorMessage.empty())
-        {
-        cmOStringStream e;
-        e << "given target \"" << te->GetName() << "\" more than once.";
-        this->ExportCommand->ErrorMessage = e.str();
-        }
+      cmOStringStream e;
+      e << "given target \"" << te->GetName() << "\" more than once.";
+      this->Makefile->GetCMakeInstance()
+          ->IssueMessage(cmake::FATAL_ERROR, e.str().c_str(), this->Backtrace);
       return false;
       }
     if (te->GetType() == cmTarget::INTERFACE_LIBRARY)
@@ -60,8 +58,8 @@ bool cmExportBuildFileGenerator::GenerateMainFile(std::ostream& os)
 
   // Create all the imported targets.
   for(std::vector<cmTarget*>::const_iterator
-        tei = allTargets.begin();
-      tei != allTargets.end(); ++tei)
+        tei = this->Exports.begin();
+      tei != this->Exports.end(); ++tei)
     {
     cmTarget* te = *tei;
     this->GenerateImportTargetCode(os, te);
@@ -116,8 +114,8 @@ cmExportBuildFileGenerator
                             std::vector<std::string> &missingTargets)
 {
   for(std::vector<cmTarget*>::const_iterator
-        tei = this->Exports->begin();
-      tei != this->Exports->end(); ++tei)
+        tei = this->Exports.begin();
+      tei != this->Exports.end(); ++tei)
     {
     // Collect import properties for this target.
     cmTarget* target = *tei;
@@ -198,40 +196,95 @@ cmExportBuildFileGenerator
 //----------------------------------------------------------------------------
 void
 cmExportBuildFileGenerator::HandleMissingTarget(
-  std::string& link_libs, std::vector<std::string>&,
-  cmMakefile*, cmTarget* depender, cmTarget* dependee)
+  std::string& link_libs, std::vector<std::string>& missingTargets,
+  cmMakefile* mf, cmTarget* depender, cmTarget* dependee)
 {
   // The target is not in the export.
   if(!this->AppendMode)
     {
-    // We are not appending, so all exported targets should be
-    // known here.  This is probably user-error.
-    this->ComplainAboutMissingTarget(depender, dependee);
+    const std::string name = dependee->GetName();
+    std::vector<std::string> namespaces = this->FindNamespaces(mf, name);
+
+    int targetOccurrences = (int)namespaces.size();
+    if (targetOccurrences == 1)
+      {
+      std::string missingTarget = namespaces[0];
+
+      missingTarget += dependee->GetExportName();
+      link_libs += missingTarget;
+      missingTargets.push_back(missingTarget);
+      return;
+      }
+    else
+      {
+      // We are not appending, so all exported targets should be
+      // known here.  This is probably user-error.
+      this->ComplainAboutMissingTarget(depender, dependee, targetOccurrences);
+      }
     }
   // Assume the target will be exported by another command.
   // Append it with the export namespace.
   link_libs += this->Namespace;
   link_libs += dependee->GetExportName();
+//   if generate time {}
+}
+
+
+//----------------------------------------------------------------------------
+std::vector<std::string>
+cmExportBuildFileGenerator
+::FindNamespaces(cmMakefile* mf, const std::string& name)
+{
+  std::vector<std::string> namespaces;
+  cmGlobalGenerator* gg = mf->GetLocalGenerator()->GetGlobalGenerator();
+
+  std::map<std::string, cmExportBuildFileGenerator*>& exportSets
+                                                  = gg->GetBuildExportSets();
+
+  for(std::map<std::string, cmExportBuildFileGenerator*>::const_iterator
+      expIt = exportSets.begin(); expIt != exportSets.end(); ++expIt)
+    {
+    const cmExportBuildFileGenerator* exportSet = expIt->second;
+    std::vector<std::string> const& targets = exportSet->GetTargets();
+
+    if (std::find(targets.begin(), targets.end(), name) != targets.end())
+      {
+      namespaces.push_back(exportSet->GetNamespace());
+      }
+    }
+
+  return namespaces;
 }
 
 //----------------------------------------------------------------------------
 void
 cmExportBuildFileGenerator
 ::ComplainAboutMissingTarget(cmTarget* depender,
-                             cmTarget* dependee)
+                             cmTarget* dependee,
+                             int occurrences)
 {
-  if(!this->ExportCommand || !this->ExportCommand->ErrorMessage.empty())
+  if(cmSystemTools::GetErrorOccuredFlag())
     {
     return;
     }
 
   cmOStringStream e;
-  e << "called with target \"" << depender->GetName()
-    << "\" which requires target \"" << dependee->GetName()
-    << "\" that is not in the export list.\n"
-    << "If the required target is not easy to reference in this call, "
+  e << "export called with target \"" << depender->GetName()
+    << "\" which requires target \"" << dependee->GetName() << "\" ";
+  if (occurrences == 0)
+    {
+    e << "that is not in the export set.\n";
+    }
+  else
+    {
+    e << "that is not in this export set, but " << occurrences
+    << " times in others.\n";
+    }
+  e << "If the required target is not easy to reference in this call, "
     << "consider using the APPEND option with multiple separate calls.";
-  this->ExportCommand->ErrorMessage = e.str();
+
+  this->Makefile->GetCMakeInstance()
+      ->IssueMessage(cmake::FATAL_ERROR, e.str().c_str(), this->Backtrace);
 }
 
 std::string
diff --git a/Source/cmExportBuildFileGenerator.h b/Source/cmExportBuildFileGenerator.h
index 3ffdf8b..2fbd98f 100644
--- a/Source/cmExportBuildFileGenerator.h
+++ b/Source/cmExportBuildFileGenerator.h
@@ -13,8 +13,7 @@
 #define cmExportBuildFileGenerator_h
 
 #include "cmExportFileGenerator.h"
-
-class cmExportCommand;
+#include "cmListFileCache.h"
 
 /** \class cmExportBuildFileGenerator
  * \brief Generate a file exporting targets from a build tree.
@@ -31,14 +30,22 @@ public:
   cmExportBuildFileGenerator();
 
   /** Set the list of targets to export.  */
-  void SetExports(std::vector<cmTarget*> const* exports)
-    { this->Exports = exports; }
+  void SetTargets(std::vector<std::string> const& targets)
+    { this->Targets = targets; }
+  std::vector<std::string> const& GetTargets() const
+    { return this->Targets; }
+  void AppendTargets(std::vector<std::string> const& targets)
+    { this->Targets.insert(this->Targets.end(),
+      targets.begin(), targets.end()); }
 
   /** Set whether to append generated code to the output file.  */
   void SetAppendMode(bool append) { this->AppendMode = append; }
 
-  /** Set the command instance through which errors should be reported.  */
-  void SetCommand(cmExportCommand* cmd) { this->ExportCommand = cmd; }
+  void SetMakefile(cmMakefile *mf) {
+    this->Makefile = mf;
+    this->Makefile->GetBacktrace(this->Backtrace);
+  }
+
 protected:
   // Implement virtual methods from the superclass.
   virtual bool GenerateMainFile(std::ostream& os);
@@ -53,7 +60,8 @@ protected:
                                    cmTarget* dependee);
 
   void ComplainAboutMissingTarget(cmTarget* depender,
-                                  cmTarget* dependee);
+                                  cmTarget* dependee,
+                                  int occurrences);
 
   /** Fill in properties indicating built file locations.  */
   void SetImportLocationProperty(const char* config,
@@ -63,8 +71,13 @@ protected:
 
   std::string InstallNameDir(cmTarget* target, const std::string& config);
 
-  std::vector<cmTarget*> const* Exports;
-  cmExportCommand* ExportCommand;
+  std::vector<std::string>
+  FindNamespaces(cmMakefile* mf, const std::string& name);
+
+  std::vector<std::string> Targets;
+  std::vector<cmTarget*> Exports;
+  cmMakefile* Makefile;
+  cmListFileBacktrace Backtrace;
 };
 
 #endif
diff --git a/Source/cmExportCommand.cxx b/Source/cmExportCommand.cxx
index f335b8b..86ddc3f 100644
--- a/Source/cmExportCommand.cxx
+++ b/Source/cmExportCommand.cxx
@@ -108,8 +108,6 @@ bool cmExportCommand
     fname += this->Filename.GetString();
     }
 
-  // Collect the targets to be exported.
-  std::vector<cmTarget*> targets;
   for(std::vector<std::string>::const_iterator
       currentTarget = this->Targets.GetVector().begin();
       currentTarget != this->Targets.GetVector().end();
@@ -128,15 +126,7 @@ bool cmExportCommand
        this->Makefile->GetLocalGenerator()->
        GetGlobalGenerator()->FindTarget(0, currentTarget->c_str()))
       {
-      if((target->GetType() == cmTarget::EXECUTABLE) ||
-         (target->GetType() == cmTarget::STATIC_LIBRARY) ||
-         (target->GetType() == cmTarget::SHARED_LIBRARY) ||
-         (target->GetType() == cmTarget::MODULE_LIBRARY) ||
-         (target->GetType() == cmTarget::INTERFACE_LIBRARY))
-        {
-        targets.push_back(target);
-        }
-      else if(target->GetType() == cmTarget::OBJECT_LIBRARY)
+      if(target->GetType() == cmTarget::OBJECT_LIBRARY)
         {
         cmOStringStream e;
         e << "given OBJECT library \"" << *currentTarget
@@ -144,37 +134,28 @@ bool cmExportCommand
         this->SetError(e.str().c_str());
         return false;
         }
-      else
-        {
-        cmOStringStream e;
-        e << "given target \"" << *currentTarget
-          << "\" which is not an executable or library.";
-        this->SetError(e.str().c_str());
-        return false;
-        }
       }
-    else
+    }
+
+  cmGlobalGenerator *gg = this->Makefile->GetLocalGenerator()
+                                        ->GetGlobalGenerator();
+  if (this->Append.IsEnabled())
+    {
+    if (cmExportBuildFileGenerator *ebfg = gg->GetExportedTargetsFile(fname))
       {
-      cmOStringStream e;
-      e << "given target \"" << *currentTarget
-        << "\" which is not built by this project.";
-      this->SetError(e.str().c_str());
-      return false;
+      ebfg->AppendTargets(this->Targets.GetVector());
+      return true;
       }
     }
 
   // Setup export file generation.
-  cmExportBuildFileGenerator ebfg;
-  ebfg.SetExportFile(fname.c_str());
-  ebfg.SetNamespace(this->Namespace.GetCString());
-  ebfg.SetAppendMode(this->Append.IsEnabled());
-  ebfg.SetExports(&targets);
-  ebfg.SetCommand(this);
-  ebfg.SetExportOld(this->ExportOld.IsEnabled());
-
-  cmGlobalGenerator *gg = this->Makefile->GetLocalGenerator()
-                                        ->GetGlobalGenerator();
-  gg->AddExportedTargetsFile(fname);
+  cmExportBuildFileGenerator *ebfg = new cmExportBuildFileGenerator;
+  ebfg->SetExportFile(fname.c_str());
+  ebfg->SetNamespace(this->Namespace.GetCString());
+  ebfg->SetAppendMode(this->Append.IsEnabled());
+  ebfg->SetTargets(this->Targets.GetVector());
+  ebfg->SetMakefile(this->Makefile);
+  ebfg->SetExportOld(this->ExportOld.IsEnabled());
 
   // Compute the set of configurations exported.
   std::vector<std::string> configurationTypes;
@@ -185,27 +166,15 @@ bool cmExportCommand
           ci = configurationTypes.begin();
         ci != configurationTypes.end(); ++ci)
       {
-      ebfg.AddConfiguration(ci->c_str());
+      ebfg->AddConfiguration(ci->c_str());
       }
     }
   else
     {
-    ebfg.AddConfiguration("");
+    ebfg->AddConfiguration("");
     }
 
-  // Generate the import file.
-  if(!ebfg.GenerateImportFile() && this->ErrorMessage.empty())
-    {
-    this->SetError("could not write export file.");
-    return false;
-    }
-
-  // Report generated error message if any.
-  if(!this->ErrorMessage.empty())
-    {
-    this->SetError(this->ErrorMessage.c_str());
-    return false;
-    }
+  gg->AddBuildExportSet(ebfg);
 
   return true;
 }
diff --git a/Source/cmExportCommand.h b/Source/cmExportCommand.h
index 87c3452..38e8d9a 100644
--- a/Source/cmExportCommand.h
+++ b/Source/cmExportCommand.h
@@ -85,7 +85,9 @@ public:
       "should never be installed.  "
       "See the install(EXPORT) command to export targets from an "
       "installation tree."
-      CM_LOCATION_UNDEFINED_BEHAVIOR("passing it to this command")
+      "\n"
+      "The properties set on the generated IMPORTED targets will have the "
+      "same values as the final values of the input TARGETS."
       "\n"
       "  export(PACKAGE <name>)\n"
       "Store the current build directory in the CMake user package registry "
diff --git a/Source/cmExportFileGenerator.cxx b/Source/cmExportFileGenerator.cxx
index 25c5710..b01e499 100644
--- a/Source/cmExportFileGenerator.cxx
+++ b/Source/cmExportFileGenerator.cxx
@@ -52,6 +52,12 @@ void cmExportFileGenerator::SetExportFile(const char* mainFile)
 }
 
 //----------------------------------------------------------------------------
+const char* cmExportFileGenerator::GetMainExportFileName() const
+{
+  return this->MainImportFile.c_str();
+}
+
+//----------------------------------------------------------------------------
 bool cmExportFileGenerator::GenerateImportFile()
 {
   // Open the output file to generate it.
diff --git a/Source/cmExportFileGenerator.h b/Source/cmExportFileGenerator.h
index 9628b96..f3d0807 100644
--- a/Source/cmExportFileGenerator.h
+++ b/Source/cmExportFileGenerator.h
@@ -33,9 +33,11 @@ public:
 
   /** Set the full path to the export file to generate.  */
   void SetExportFile(const char* mainFile);
+  const char *GetMainExportFileName() const;
 
   /** Set the namespace in which to place exported target names.  */
   void SetNamespace(const char* ns) { this->Namespace = ns; }
+  std::string GetNamespace() const { return this->Namespace; }
 
   void SetExportOld(bool exportOld) { this->ExportOld = exportOld; }
 
diff --git a/Source/cmExportInstallFileGenerator.cxx b/Source/cmExportInstallFileGenerator.cxx
index c71008e..133944e 100644
--- a/Source/cmExportInstallFileGenerator.cxx
+++ b/Source/cmExportInstallFileGenerator.cxx
@@ -432,8 +432,8 @@ cmExportInstallFileGenerator::HandleMissingTarget(
     }
   else
     {
-    // We are not appending, so all exported targets should be
-    // known here.  This is probably user-error.
+    // All exported targets should be known here and should be unique.
+    // This is probably user-error.
     this->ComplainAboutMissingTarget(depender, dependee, targetOccurrences);
     }
 }
diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index eacf85b..fb205be 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -27,6 +27,7 @@
 #include "cmGeneratorTarget.h"
 #include "cmGeneratorExpression.h"
 #include "cmGeneratorExpressionEvaluationFile.h"
+#include "cmExportBuildFileGenerator.h"
 
 #include <cmsys/Directory.hxx>
 
@@ -77,6 +78,12 @@ cmGlobalGenerator::~cmGlobalGenerator()
     {
     delete *li;
     }
+  for(std::map<std::string, cmExportBuildFileGenerator*>::iterator
+        i = this->BuildExportSets.begin();
+      i != this->BuildExportSets.end(); ++i)
+    {
+    delete i->second;
+    }
   this->LocalGenerators.clear();
 
   if (this->ExtraGenerator)
@@ -183,6 +190,34 @@ void cmGlobalGenerator::ResolveLanguageCompiler(const std::string &lang,
                          doc.c_str(), cmCacheManager::FILEPATH);
 }
 
+void cmGlobalGenerator::AddBuildExportSet(cmExportBuildFileGenerator* gen)
+{
+  this->BuildExportSets[gen->GetMainExportFileName()] = gen;
+}
+
+bool cmGlobalGenerator::GenerateImportFile(const std::string &file)
+{
+  std::map<std::string, cmExportBuildFileGenerator*>::iterator it
+                                          = this->BuildExportSets.find(file);
+  if (it != this->BuildExportSets.end())
+    {
+    bool result = it->second->GenerateImportFile();
+    delete it->second;
+    it->second = 0;
+    this->BuildExportSets.erase(it);
+    return result;
+    }
+  return false;
+}
+
+bool
+cmGlobalGenerator::IsExportedTargetsFile(const std::string &filename) const
+{
+  const std::map<std::string, cmExportBuildFileGenerator*>::const_iterator it
+                                      = this->BuildExportSets.find(filename);
+  return it != this->BuildExportSets.end();
+}
+
 // Find the make program for the generator, required for try compiles
 void cmGlobalGenerator::FindMakeProgram(cmMakefile* mf)
 {
@@ -966,6 +1001,14 @@ void cmGlobalGenerator::Configure()
     }
 }
 
+cmExportBuildFileGenerator*
+cmGlobalGenerator::GetExportedTargetsFile(const std::string &filename) const
+{
+  std::map<std::string, cmExportBuildFileGenerator*>::const_iterator it
+    = this->BuildExportSets.find(filename);
+  return it == this->BuildExportSets.end() ? 0 : it->second;
+}
+
 bool cmGlobalGenerator::CheckALLOW_DUPLICATE_CUSTOM_TARGETS()
 {
   // If the property is not enabled then okay.
@@ -1091,6 +1134,19 @@ void cmGlobalGenerator::Generate()
     }
   this->SetCurrentLocalGenerator(0);
 
+  for (std::map<std::string, cmExportBuildFileGenerator*>::iterator
+      it = this->BuildExportSets.begin(); it != this->BuildExportSets.end();
+      ++it)
+    {
+    if (!it->second->GenerateImportFile()
+        && !cmSystemTools::GetErrorOccuredFlag())
+      {
+      this->GetCMakeInstance()
+          ->IssueMessage(cmake::FATAL_ERROR, "Could not write export file.",
+                        cmListFileBacktrace());
+      return;
+      }
+    }
   // Update rule hashes.
   this->CheckRuleHashes();
 
diff --git a/Source/cmGlobalGenerator.h b/Source/cmGlobalGenerator.h
index b8860f1..c930b2b 100644
--- a/Source/cmGlobalGenerator.h
+++ b/Source/cmGlobalGenerator.h
@@ -31,6 +31,7 @@ class cmExternalMakefileProjectGenerator;
 class cmTarget;
 class cmInstallTargetGenerator;
 class cmInstallFilesGenerator;
+class cmExportBuildFileGenerator;
 
 /** \class cmGlobalGenerator
  * \brief Responable for overseeing the generation process for the entire tree
@@ -293,18 +294,13 @@ public:
 
   void ProcessEvaluationFiles();
 
-  void AddExportedTargetsFile(const std::string &filename)
-  {
-    this->ExportedTargetsFiles.insert(filename);
-  }
-
-  bool IsExportedTargetsFile(const std::string &filename) const
-  {
-    const std::set<std::string>::const_iterator it
-                                  = this->ExportedTargetsFiles.find(filename);
-    return it != this->ExportedTargetsFiles.end();
-  }
-
+  std::map<std::string, cmExportBuildFileGenerator*>& GetBuildExportSets()
+    {return this->BuildExportSets;}
+  void AddBuildExportSet(cmExportBuildFileGenerator*);
+  bool IsExportedTargetsFile(const std::string &filename) const;
+  bool GenerateImportFile(const std::string &file);
+  cmExportBuildFileGenerator*
+  GetExportedTargetsFile(const std::string &filename) const;
 protected:
   typedef std::vector<cmLocalGenerator*> GeneratorVector;
   // for a project collect all its targets by following depend
@@ -356,6 +352,7 @@ protected:
   bool InstallTargetEnabled;
   // Sets of named target exports
   cmExportSetMap ExportSets;
+  std::map<std::string, cmExportBuildFileGenerator*> BuildExportSets;
 
   // Manifest of all targets that will be built for each configuration.
   // This is computed just before local generators generate.
@@ -384,7 +381,6 @@ private:
   std::map<cmStdString, cmStdString> ExtensionToLanguage;
   std::map<cmStdString, int> LanguageToLinkerPreference;
   std::map<cmStdString, cmStdString> LanguageToOriginalSharedLibFlags;
-  std::set<std::string> ExportedTargetsFiles;
 
   // Record hashes for rules and outputs.
   struct RuleHash { char Data[32]; };
diff --git a/Source/cmIncludeCommand.cxx b/Source/cmIncludeCommand.cxx
index 39d4993..5b93171 100644
--- a/Source/cmIncludeCommand.cxx
+++ b/Source/cmIncludeCommand.cxx
@@ -127,6 +127,7 @@ bool cmIncludeCommand
         return false;
         }
       }
+    gg->GenerateImportFile(fname_abs);
     }
 
   std::string fullFilePath;
diff --git a/Tests/RunCMake/CMP0022/CMP0022-export-stderr.txt b/Tests/RunCMake/CMP0022/CMP0022-export-stderr.txt
index ae7627e..405dd8d 100644
--- a/Tests/RunCMake/CMP0022/CMP0022-export-stderr.txt
+++ b/Tests/RunCMake/CMP0022/CMP0022-export-stderr.txt
@@ -1,4 +1,4 @@
-CMake Error at CMP0022-export.cmake:11 \(export\):
+CMake Error in CMakeLists.txt:
   Target "cmp0022NEW" has policy CMP0022 enabled, but also has old-style
   LINK_INTERFACE_LIBRARIES properties populated, but it was exported without
   the EXPORT_LINK_INTERFACE_LIBRARIES to export the old-style properties
diff --git a/Tests/RunCMake/ExportWithoutLanguage/NoLanguage-stderr.txt b/Tests/RunCMake/ExportWithoutLanguage/NoLanguage-stderr.txt
index 67a0ae3..5658d85 100644
--- a/Tests/RunCMake/ExportWithoutLanguage/NoLanguage-stderr.txt
+++ b/Tests/RunCMake/ExportWithoutLanguage/NoLanguage-stderr.txt
@@ -1,6 +1,4 @@
 CMake Error: CMake can not determine linker language for target: NoLanguage
-CMake Error at NoLanguage.cmake:2 \(export\):
+CMake Error in CMakeLists.txt:
   Exporting the target "NoLanguage" is not allowed since its linker language
   cannot be determined
-Call Stack \(most recent call first\):
-  CMakeLists.txt:3 \(include\)
diff --git a/Tests/RunCMake/ExportWithoutLanguage/header.h b/Tests/RunCMake/ExportWithoutLanguage/header.h
new file mode 100644
index 0000000..0c803ed
--- /dev/null
+++ b/Tests/RunCMake/ExportWithoutLanguage/header.h
@@ -0,0 +1,2 @@
+
+enum some_compilers { need_more_than_nothing };