CPP: Fix for functions with no definition.

Author: geoffw0

cpp/ql/src/Critical/LargeParameter.ql

@@ -30,6 +30,8 @@ where f.getAParameter() = p
       exists(FunctionCall fc | fc.getQualifier().getAChild*() = a and not fc.getTarget().hasSpecifier("const"))
     )
   )
+  // if there's no block, we can't tell how the parameter is used
+  and exists(f.getBlock())
 select
   p, "This parameter of type $@ is " + size.toString() + " bytes - consider passing a const pointer/reference instead.",
   t, t.toString()

cpp/ql/test/query-tests/Critical/LargeParameter/LargeParameter.expected

@@ -7,4 +7,3 @@
 | test.cpp:107:16:107:16 | d | This parameter of type $@ is 4100 bytes - consider passing a const pointer/reference instead. | test.cpp:58:8:58:19 | MyLargeClass | MyLargeClass |
 | test.cpp:108:16:108:16 | e | This parameter of type $@ is 4100 bytes - consider passing a const pointer/reference instead. | test.cpp:58:8:58:19 | MyLargeClass | MyLargeClass |
 | test.cpp:109:16:109:16 | f | This parameter of type $@ is 4100 bytes - consider passing a const pointer/reference instead. | test.cpp:58:8:58:19 | MyLargeClass | MyLargeClass |
-| test.cpp:149:31:149:31 | a | This parameter of type $@ is 4100 bytes - consider passing a const pointer/reference instead. | test.cpp:58:8:58:19 | MyLargeClass | MyLargeClass |

cpp/ql/test/query-tests/Critical/LargeParameter/test.cpp

@@ -146,4 +146,4 @@ MyArithmeticClass operator+(MyArithmeticClass lhs, const MyArithmeticClass &rhs)
 	return lhs;
 }
 
-void myFunction6(MyLargeClass a); // GOOD (no definition, so we can't tell what's done with `a`) [FALSE POSITIVE]
+void myFunction6(MyLargeClass a); // GOOD (no definition, so we can't tell what's done with `a`)