C++: Move mayBeFromImplicitlyDeclaredFunction to Call

cpp/ql/lib/semmle/code/cpp/exprs/Call.qll

@@ -149,6 +149,11 @@ class Call extends Expr, NameQualifiableElement, TCall {
     variableAddressEscapesTreeNonConst(va, this.getQualifier().getFullyConverted()) and
     i = -1
   }
+
+  /** Holds if this expression could be the return value of an implicitly declared function. */
+  predicate mayBeFromImplicitlyDeclaredFunction() {
+    this.getTarget().getADeclarationEntry().isImplicit()
+  }
 }
 
 /**
@@ -300,10 +305,6 @@ class FunctionCall extends Call, @funbindexpr {
     this.isVirtual() or
     this.getTarget().getAnAttribute().getName() = "weak"
   }
-
-  override predicate mayBeFromImplicitlyDeclaredFunction() {
-    this.getTarget().getADeclarationEntry().isImplicit()
-  }
 }
 
 /** A _user-defined_ unary `operator*` function. */

cpp/ql/lib/semmle/code/cpp/exprs/Expr.qll

@@ -534,9 +534,6 @@ class Expr extends StmtParent, @expr {
 
   /** Gets the function containing this control-flow node. */
   override Function getControlFlowScope() { result = this.getEnclosingFunction() }
-
-  /** Holds if this expression could be the return value of an implicitly declared function. */
-  predicate mayBeFromImplicitlyDeclaredFunction() { none() }
 }
 
 /**

cpp/ql/src/Likely Bugs/Format/WrongTypeFormatArguments.ql

@@ -171,7 +171,7 @@ where
   not arg.isAffectedByMacro() and
   not arg.isFromUninstantiatedTemplate(_) and
   not actual.getUnspecifiedType() instanceof ErroneousType and
-  not arg.mayBeFromImplicitlyDeclaredFunction()
+  not arg.(Call).mayBeFromImplicitlyDeclaredFunction()
 select arg,
   "This format specifier for type '" + expected.getName() + "' does not match the argument type '" +
     actual.getUnspecifiedType().getName() + "'."

cpp/ql/test/library-tests/exprs/implicitly_declared/implicit.ql

@@ -1,5 +1,5 @@
 import cpp
 
-from Expr e
-where e.mayBeFromImplicitlyDeclaredFunction()
-select e
+from Call c
+where c.mayBeFromImplicitlyDeclaredFunction()
+select c