Merge pull request #4532 from geoffw0/wrongtypeformaterr

C++: Harden queries against ErroneousType

cpp/change-notes/2020-10-21-erroneous-types.md

@@ -0,0 +1,2 @@
+lgtm,codescanning
+* The `cpp/wrong-type-format-argument` and `cpp/non-portable-printf` queries have been hardened so that they do not produce nonsensical results on databases that contain errors (specifically the `ErroneousType`).

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

@@ -155,7 +155,8 @@ where
     not actual.getUnspecifiedType().(IntegralType).getSize() = sizeof_IntType()
   ) and
   not arg.isAffectedByMacro() and
-  not arg.isFromUninstantiatedTemplate(_)
+  not arg.isFromUninstantiatedTemplate(_) and
+  not actual.getUnspecifiedType() instanceof ErroneousType
 select arg,
   "This argument should be of type '" + expected.getName() + "' but is of type '" +
     actual.getUnspecifiedType().getName() + "'"

cpp/ql/src/Likely Bugs/Memory Management/Padding/NonPortablePrintf.ql

@@ -88,7 +88,8 @@ where
   not arg.isAffectedByMacro() and
   size32 = ilp32.paddedSize(actual) and
   size64 = lp64.paddedSize(actual) and
-  size64 != size32
+  size64 != size32 and
+  not actual instanceof ErroneousType
 select arg,
   "This argument should be of type '" + expected.getName() + "' but is of type '" + actual.getName()
     + "' (which changes size from " + size32 + " to " + size64 + " on 64-bit systems)."