Defer check for sources within a target until generation.

The `add_library` and `add_executable` commands can now be called with
no source-files and won't generate a warning or error message, as long
as source-files will be added later via the `target_sources` command.
If during the generation step still no sources are associated with
targets created by such calls a useful error message will be generated
and generation fails.

Targets of type `INTERFACE_LIBRARY`, `UTILITY` or `GLOBAL_TARGET` are
excluded from this check because we do not need sources for these target
types during generation.

Fixes: #16872

1 files changed, 0 insertions, 8 deletions

diff --git a/Source/cmAddLibraryCommand.cxx b/Source/cmAddLibraryCommand.cxx
index ebf1763..31c2ecf 100644
--- a/Source/cmAddLibraryCommand.cxx
+++ b/Source/cmAddLibraryCommand.cxx
@@ -362,14 +362,6 @@ bool cmAddLibraryCommand::InitialPass(std::vector<std::string> const& args,
     return true;
   }
 
-  if (s == args.end()) {
-    std::string msg = "You have called ADD_LIBRARY for library ";
-    msg += args[0];
-    msg += " without any source files. This typically indicates a problem ";
-    msg += "with your CMakeLists.txt file";
-    cmSystemTools::Message(msg.c_str(), "Warning");
-  }
-
   srclists.insert(srclists.end(), s, args.end());
 
   this->Makefile->AddLibrary(libName, type, srclists, excludeFromAll);