Fix export of STATIC library PRIVATE non-target dependencies

In commit v3.5.0-rc1~43^2 (Fix export of STATIC library PRIVATE
dependencies with CMP0022 NEW, 2016-01-15) we taught
target_link_libraries to generate `$<LINK_ONLY:$<TARGET_NAME:dep>>` in
INTERFACE_LINK_LIBRARIES instead of `$<LINK_ONLY:dep>` so that `dep` can
be recognized as a target name and updated during export.  However, this
approach does not work when `dep` is just a plain library name and not a
target because `$<TARGET_NAME:...>` requires the name of a reachable
target.

Since we do not know during target_link_libraries whether the name will
correspond to a reachable target or not, we cannot inject the
`$<TARGET_NAME:...>` expression.  Revert this change and solve the
original problem instead by teaching the export logic to recognize and
update target names directly in `$<LINK_ONLY:...>` expressions.

Reported-by: Ben Boeckel <ben.boeckel@kitware.com>

1 files changed, 2 insertions, 5 deletions

diff --git a/Source/cmTargetLinkLibrariesCommand.cxx b/Source/cmTargetLinkLibrariesCommand.cxx
index 5f3246a..435346a 100644
--- a/Source/cmTargetLinkLibrariesCommand.cxx
+++ b/Source/cmTargetLinkLibrariesCommand.cxx
@@ -432,11 +432,8 @@ cmTargetLinkLibrariesCommand::HandleLibrary(const std::string& lib,
         {
         std::string configLib = this->Target
                                      ->GetDebugGeneratorExpressions(lib, llt);
-        if (cmGeneratorExpression::IsValidTargetName(configLib))
-          {
-          configLib = "$<LINK_ONLY:$<TARGET_NAME:" + configLib + ">>";
-          }
-        else if (cmGeneratorExpression::Find(configLib) != std::string::npos)
+        if (cmGeneratorExpression::IsValidTargetName(lib)
+            || cmGeneratorExpression::Find(lib) != std::string::npos)
           {
           configLib = "$<LINK_ONLY:" + configLib + ">";
           }