Migrate Rule 21.2 to the ReservedNames library

Author: lcartey

c/misra/src/rules/RULE-21-1/DefineAndUndefUsedOnReservedIdentifierOrMacroName.ql

@@ -16,23 +16,10 @@
 
 import cpp
 import codingstandards.c.misra
-import codingstandards.cpp.Naming
+import codingstandards.cpp.ReservedNames
 
-from PreprocessorDirective p, string name
+from PreprocessorDirective p, string message
 where
   not isExcluded(p, Preprocessor4Package::defineAndUndefUsedOnReservedIdentifierOrMacroNameQuery()) and
-  (
-    p.(Macro).hasName(name)
-    or
-    p.(PreprocessorUndef).getName() = name
-  ) and
-  (
-    Naming::Cpp14::hasStandardLibraryMacroName(name)
-    or
-    Naming::Cpp14::hasStandardLibraryObjectName(name)
-    or
-    name.regexpMatch("_.*")
-    or
-    name = "defined"
-  )
-select p, "Reserved identifier '" + name + "' has been undefined or redefined."
+  ReservedNames::C11::isAReservedIdentifier(p, message, false)
+select p, message

c/misra/test/rules/RULE-21-1/DefineAndUndefUsedOnReservedIdentifierOrMacroName.expected

@@ -1,3 +1,3 @@
-| test.c:1:1:1:17 | #define _NOT_OKAY | Reserved identifier '_NOT_OKAY' has been undefined or redefined. |
-| test.c:2:1:2:16 | #undef _NOT_OKAY | Reserved identifier '_NOT_OKAY' has been undefined or redefined. |
-| test.c:5:1:5:13 | #define errno | Reserved identifier 'errno' has been undefined or redefined. |
+| test.c:1:1:1:17 | #define _NOT_OKAY | Macro '_NOT_OKAY' declares a reserved name beginning _ followed by an uppercase letter. |
+| test.c:2:1:2:16 | #undef _NOT_OKAY | Undef '_NOT_OKAY' declares a reserved name beginning _ followed by an uppercase letter. |
+| test.c:5:1:5:13 | #define errno | Macro 'errno' declares a name reserved for a macro from the C11 standard library header 'errno.h'. |

cpp/common/src/codingstandards/cpp/ReservedNames.qll

@@ -131,6 +131,11 @@ module ReservedNames {
         scope = MacroScope() and
         cNameSpace = MacroNameSpace() and
         identifierDescription = "Macro parameter"
+        or
+        e.(PreprocessorUndef).getName() = identifierName and
+        scope = MacroScope() and
+        cNameSpace = MacroNameSpace() and
+        identifierDescription = "Undef"
       )
     }
 
@@ -148,7 +153,13 @@ module ReservedNames {
 
     module TargetedCLibrary = CStandardLibrary::C11;
 
-    predicate isAReservedIdentifier(Element m, string message) {
+    /**
+     * Holds if the given C program element is a reserved identifier according to the C11 standard or MISRA.
+     *
+     * @param requireHeaderIncluded false if we don't require
+     */
+    predicate isAReservedIdentifier(Element m, string message, boolean requireHeaderIncluded) {
+      requireHeaderIncluded = [true, false] and
       exists(
         string name, Scope scope, CNameSpace cNameSpace, string reason, string identifierDescription
       |
@@ -187,8 +198,8 @@ module ReservedNames {
         // > unless explicitly stated otherwise (see 7.1.4).
         exists(string header |
           TargetedCLibrary::hasMacroName(header, name, _) and
-          // The relevant header is included directly or transitively by the file
-          m.getFile().getAnIncludedFile*().getBaseName() = header and
+          // The relevant header is included directly or transitively by the file, or we don't apply that requirement
+          (m.getFile().getAnIncludedFile*().getBaseName() = header or requireHeaderIncluded = false) and
           reason =
             "declares a name reserved for a macro from the " + TargetedCLibrary::getName() +
               " standard library header '" + header + "'"
@@ -272,8 +283,8 @@ module ReservedNames {
             or
             scope = MacroScope()
           ) and
-          // The relevant header is included directly or transitively by the file
-          m.getFile().getAnIncludedFile*().getBaseName() = header and
+          // The relevant header is included directly or transitively by the file, or we don't apply that requirement
+          (m.getFile().getAnIncludedFile*().getBaseName() = header or requireHeaderIncluded = false) and
           reason =
             "declares a reserved name from the " + TargetedCLibrary::getName() +
               " standard library header '" + header +

cpp/common/src/codingstandards/cpp/rules/declaredareservedidentifier/DeclaredAReservedIdentifier.qll

@@ -13,5 +13,7 @@ Query getQuery() { result instanceof DeclaredAReservedIdentifierSharedQuery }
 
 query predicate problems(Element m, string message) {
   not isExcluded(m, getQuery()) and
-  ReservedNames::C11::isAReservedIdentifier(m, message)
+  ReservedNames::C11::isAReservedIdentifier(m, message, true) and
+  // Not covered by this rule
+  not m instanceof PreprocessorUndef
 }