resolve calls to signature predicates

Author: erik-krogh

ql/ql/src/codeql_ql/ast/internal/Predicate.qll

@@ -69,6 +69,12 @@ private module Cached {
     |
       definesPredicate(m, pc.getPredicateName(), pc.getNumberOfArguments(), p, public)
     )
+    or
+    exists(Module mod, PredicateExpr sig |
+      mod.hasParameter(_, pc.getPredicateName(), sig) and
+      p = sig.getResolvedPredicate() and // <- this is a `signature predicate`, but that's fine.
+      sig.getArity() = pc.getNumberOfArguments()
+    )
   }
 
   private predicate resolveMemberCall(MemberCall mc, PredicateOrBuiltin p) {

ql/ql/src/codeql_ql/style/DeadCodeQuery.qll

@@ -164,6 +164,9 @@ private AstNode aliveStep(AstNode prev) {
   result = prev.(Annotation).getAChild()
   or
   result = prev.(Predicate).getReturnType().getDeclaration()
+  or
+  // a module parameter is alive is the module is alive
+  prev.(Module).hasParameter(_, _, result)
 }
 
 private AstNode deprecated() {