add_library: Allow arbitrary non-linked sources in OBJECT libraries

Loosen this restriction on OBJECT libraries to allow source files of any
name to be generated by custom commands or listed for reference in IDE
projects so long as they would not affect linking of a normal library.
Update the rejection message to be more specific about the looser
restriction.

Extend the ObjectLibrary test to cover a ".cmake" file generated by a
custom command in an OBJECT library.

1 files changed, 2 insertions, 5 deletions

diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index eccb06a..64c5822 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -38,7 +38,8 @@ void reportBadObjLib(std::vector<cmSourceFile*> const& badObjLib,
       {
       e << "  " << (*i)->GetLocation().GetName() << "\n";
       }
-    e << "but may contain only headers and sources that compile.";
+    e << "but may contain only sources that compile, header files, and "
+         "other files that would not affect linking of a normal library.";
     cm->IssueMessage(cmake::FATAL_ERROR, e.str(),
                      target->GetBacktrace());
     }
@@ -205,10 +206,6 @@ struct TagVisitor
     else
       {
       DoAccept<IsSameTag<Tag, ExtraSourcesTag>::Result>::Do(this->Data, sf);
-      if(this->IsObjLib && ext != "txt")
-        {
-        this->BadObjLibFiles.push_back(sf);
-        }
       }
   }
 };