Allow imported INTERFACE libraries to specify a link library name

Add an `IMPORTED_LIBNAME[_<CONFIG>]` target property to specify a library
name to be placed on the link line in place of an interface library
since it has no library file of its own.  Restrict use of the property
to imported `INTERFACE` libraries.

This will be particularly useful for find modules that need to provide
imported libraries from system SDKs where the full path to the library
file is not known.  Now such find modules will be able to provide an
imported interface library and set `IMPORTED_LIBNAME` to refer to the
SDK library by name.

Issue: #15267

1 files changed, 6 insertions, 0 deletions

diff --git a/Source/cmComputeLinkInformation.cxx b/Source/cmComputeLinkInformation.cxx
index 28aa533324..80e7e7da1b 100644
--- a/Source/cmComputeLinkInformation.cxx
+++ b/Source/cmComputeLinkInformation.cxx
@@ -606,6 +606,12 @@ void cmComputeLinkInformation::AddItem(std::string const& item,
       // of COMPATIBLE_INTERFACE_ enforcement.  The generators will ignore
       // this for the actual link line.
       this->Items.push_back(Item(std::string(), false, tgt));
+
+      // Also add the item the interface specifies to be used in its place.
+      std::string const& libName = tgt->GetImportedLibName(config);
+      if (!libName.empty()) {
+        this->AddItem(libName, CM_NULLPTR);
+      }
     } else {
       // Decide whether to use an import library.
       bool implib =