exports: accept a missing target if it is exported exactly once

If a target is exported, and a library it depends on is not part
of the same export set, before this patch cmake errored out.
With this patch, it now checks whether the missing target
is exported somewhere else exactly once, and accepts in this
case (because then it can determine the namespace for the
missing target and use this).

Alex

1 files changed, 67 insertions, 9 deletions

diff --git a/Source/cmExportFileGenerator.cxx b/Source/cmExportFileGenerator.cxx
index eb19df5e..fa6cc9f 100644
--- a/Source/cmExportFileGenerator.cxx
+++ b/Source/cmExportFileGenerator.cxx
@@ -11,10 +11,15 @@
 ============================================================================*/
 #include "cmExportFileGenerator.h"
 
+#include "cmExportSet.h"
 #include "cmGeneratedFileStream.h"
+#include "cmGlobalGenerator.h"
+#include "cmInstallExportGenerator.h"
+#include "cmLocalGenerator.h"
 #include "cmMakefile.h"
 #include "cmSystemTools.h"
 #include "cmTarget.h"
+#include "cmTargetExport.h"
 #include "cmVersion.h"
 
 #include <cmsys/auto_ptr.hxx>
@@ -224,17 +229,28 @@ cmExportFileGenerator
         }
       else
         {
-        // The target is not in the export.
-        if(!this->AppendMode)
+        std::vector<std::string> namespaces = this->FindNamespaces(mf, *li);
+        int targetOccurrences = (int)namespaces.size();
+
+        if (targetOccurrences == 1)
           {
-          // We are not appending, so all exported targets should be
-          // known here.  This is probably user-error.
-          this->ComplainAboutMissingTarget(target, tgt);
+          link_libs += namespaces[0];
+          link_libs += *li;
+          }
+        else
+          {
+          // 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(target, tgt, targetOccurrences);
+            }
+          // Assume the target will be exported by another command.
+          // Append it with the export namespace.
+          link_libs += this->Namespace;
+          link_libs += *li;
           }
-        // Assume the target will be exported by another command.
-        // Append it with the export namespace.
-        link_libs += this->Namespace;
-        link_libs += *li;
         }
       }
     else
@@ -250,6 +266,48 @@ cmExportFileGenerator
   properties[prop] = link_libs;
 }
 
+
+//----------------------------------------------------------------------------
+std::vector<std::string> cmExportFileGenerator::FindNamespaces(cmMakefile* mf,
+                                                       const std::string& name)
+{
+  std::vector<std::string> namespaces;
+  cmGlobalGenerator* gg = mf->GetLocalGenerator()->GetGlobalGenerator();
+  const cmExportSetMap& exportSets = gg->GetExportSets();
+
+  for(cmExportSetMap::const_iterator expIt = exportSets.begin();
+      expIt != exportSets.end();
+      ++expIt)
+    {
+    const cmExportSet* exportSet = expIt->second;
+    std::vector<cmTargetExport const*> const* targets =
+                                                 exportSet->GetTargetExports();
+
+    bool containsTarget = false;
+    for(unsigned int i=0; i<targets->size(); i++)
+      {
+      if (name == (*targets)[i]->Target->GetName())
+        {
+        containsTarget = true;
+        break;
+        }
+      }
+
+    if (containsTarget)
+      {
+      std::vector<cmInstallExportGenerator const*> const* installs =
+                                                 exportSet->GetInstallations();
+      for(unsigned int i=0; i<installs->size(); i++)
+        {
+        namespaces.push_back((*installs)[i]->GetNamespace());
+        }
+      }
+    }
+
+  return namespaces;
+}
+
+
 //----------------------------------------------------------------------------
 void cmExportFileGenerator::GenerateImportHeaderCode(std::ostream& os,
                                                      const char* config)