ENH: Add UNKNOWN type for IMPORTED libraries

When creating an IMPORTED target for a library that has been found on
disk, it may not be known whether the library is STATIC or SHARED.
However, the library may still be linked using the file found from disk.
Use of an IMPORTED target is still important to allow per-configuration
files to be specified for the library.

This change creates an UNKNOWN type for IMPORTED library targets.  The
IMPORTED_LOCATION property (and its per-config equivalents) specifies
the location of the library.  CMake makes no assumptions about the
library that cannot be inferred from the file on disk.  This will help
projects and find-modules import targets found on disk or specified by
the user.

1 files changed, 10 insertions, 2 deletions

diff --git a/Source/cmComputeLinkDepends.cxx b/Source/cmComputeLinkDepends.cxx
index 177ec58..df329a6 100644
--- a/Source/cmComputeLinkDepends.cxx
+++ b/Source/cmComputeLinkDepends.cxx
@@ -891,6 +891,14 @@ void cmComputeLinkDepends::CheckWrongConfigItem(std::string const& item)
 }
 
 //----------------------------------------------------------------------------
+static bool cmComputeLinkDependsNotStatic(cmTarget* tgt)
+{
+  return (tgt &&
+          tgt->GetType() != cmTarget::STATIC_LIBRARY &&
+          tgt->GetType() != cmTarget::UNKNOWN_LIBRARY);
+}
+
+//----------------------------------------------------------------------------
 void cmComputeLinkDepends::PreserveOriginalEntries()
 {
   // Skip the part of the input sequence that already appears in the
@@ -901,7 +909,7 @@ void cmComputeLinkDepends::PreserveOriginalEntries()
         out != this->FinalLinkOrder.end())
     {
     cmTarget* tgt = this->EntryList[*in].Target;
-    if(tgt && tgt->GetType() != cmTarget::STATIC_LIBRARY)
+    if(cmComputeLinkDependsNotStatic(tgt))
       {
       // Skip input items known to not be static libraries.
       ++in;
@@ -924,7 +932,7 @@ void cmComputeLinkDepends::PreserveOriginalEntries()
   while(in != this->OriginalEntries.end())
     {
     cmTarget* tgt = this->EntryList[*in].Target;
-    if(tgt && tgt->GetType() != cmTarget::STATIC_LIBRARY)
+    if(cmComputeLinkDependsNotStatic(tgt))
       {
       // Skip input items known to not be static libraries.
       ++in;