shiboken6/Type system parser: Use contiguous enum for StackElement

The old approach with the bit masks does not really scale
and makes it hard to add new values. Replace by a contiguous enum
with First/Last entries and check functions.

Task-number: PYSIDE-454
Change-Id: If34942ce0d2e496f34a17a84a7c8406895cf1c16
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

2 files changed, 108 insertions, 90 deletions

diff --git a/sources/shiboken6/ApiExtractor/typesystemparser.cpp b/sources/shiboken6/ApiExtractor/typesystemparser.cpp
index 4a615420e..9ab7118cc 100644
--- a/sources/shiboken6/ApiExtractor/typesystemparser.cpp
+++ b/sources/shiboken6/ApiExtractor/typesystemparser.cpp
@@ -118,6 +118,21 @@ static inline QString yesAttributeValue() { return QStringLiteral("yes"); }
 static inline QString trueAttributeValue() { return QStringLiteral("true"); }
 static inline QString falseAttributeValue() { return QStringLiteral("false"); }
 
+static bool isTypeEntry(StackElement el)
+{
+    return el >= StackElement::FirstTypeEntry && el <= StackElement::LastTypeEntry;
+}
+
+static bool isComplexTypeEntry(StackElement el)
+{
+    return el >= StackElement::FirstTypeEntry && el <= StackElement::LastComplexTypeEntry;
+}
+
+static bool isDocumentation(StackElement el)
+{
+    return el >= StackElement::FirstDocumentation && el <= StackElement::LastDocumentation;
+}
+
 static QList<CustomConversion *> customConversionsForReview;
 
 // Set a regular expression for rejection from text. By legacy, those are fixed
@@ -993,10 +1008,8 @@ bool TypeSystemParser::endElement(StackElement element)
         break;
     }
 
-    if ((element & StackElement::TypeEntryMask) != 0
-        || element == StackElement::Root) {
+    if (isTypeEntry(element) || element == StackElement::Root)
         m_contextStack.pop();
-    }
 
     return true;
 }
@@ -1112,7 +1125,7 @@ bool TypeSystemParser::characters(const String &ch)
         return true;
     }
 
-    if ((type & StackElement::DocumentationMask) != 0)
+    if (isDocumentation(type))
         m_contextStack.top()->docModifications.last().setCode(ch);
 
     return true;
@@ -1891,11 +1904,11 @@ bool TypeSystemParser::parseRenameFunction(const ConditionalStreamReader &,
 bool TypeSystemParser::parseInjectDocumentation(const ConditionalStreamReader &, StackElement topElement,
                                        QXmlStreamAttributes *attributes)
 {
-    const auto validParent = StackElement::TypeEntryMask
-                            | StackElement::ModifyFunction
-                            | StackElement::ModifyField
-                            | StackElement::AddFunction;
-    if ((topElement & validParent) == 0) {
+    const bool validParent = isTypeEntry(topElement)
+        || topElement == StackElement::ModifyFunction
+        || topElement == StackElement::ModifyField
+        || topElement == StackElement::AddFunction;
+    if (!validParent) {
         m_error = u"inject-documentation must be inside modify-function, add-function"
                    "modify-field or other tags that creates a type"_qs;
         return false;
@@ -1924,8 +1937,7 @@ bool TypeSystemParser::parseInjectDocumentation(const ConditionalStreamReader &,
         }
     }
 
-    QString signature = topElement & StackElement::TypeEntryMask
-        ? QString() : m_currentSignature;
+    QString signature = isTypeEntry(topElement) ? QString() : m_currentSignature;
     DocModification mod(mode, signature);
     mod.setFormat(lang);
     m_contextStack.top()->docModifications << mod;
@@ -1936,10 +1948,10 @@ bool TypeSystemParser::parseModifyDocumentation(const ConditionalStreamReader &,
                                        StackElement topElement,
                                        QXmlStreamAttributes *attributes)
 {
-    const auto validParent = StackElement::TypeEntryMask
-                            | StackElement::ModifyFunction
-                            | StackElement::ModifyField;
-    if ((topElement & validParent) == 0) {
+    const bool validParent = isTypeEntry(topElement)
+        || topElement == StackElement::ModifyFunction
+        || topElement == StackElement::ModifyField;
+    if (!validParent) {
         m_error = QLatin1String("modify-documentation must be inside modify-function, "
                                 "modify-field or other tags that creates a type");
         return false;
@@ -1952,7 +1964,7 @@ bool TypeSystemParser::parseModifyDocumentation(const ConditionalStreamReader &,
     }
 
     const QString xpath = attributes->takeAt(xpathIndex).value().toString();
-    QString signature = (topElement & StackElement::TypeEntryMask) ? QString() : m_currentSignature;
+    QString signature = isTypeEntry(topElement) ? QString() : m_currentSignature;
     m_contextStack.top()->docModifications
         << DocModification(xpath, signature);
     return true;
@@ -2425,8 +2437,10 @@ bool TypeSystemParser::parseAddFunction(const ConditionalStreamReader &,
                                         StackElement t,
                                         QXmlStreamAttributes *attributes)
 {
-    if (!(topElement
-          & (StackElement::ComplexTypeEntryMask | StackElement::Root | StackElement::ContainerTypeEntry))) {
+    const bool validParent = isComplexTypeEntry(topElement)
+        || topElement == StackElement::Root
+        || topElement ==  StackElement::ContainerTypeEntry;
+    if (!validParent) {
         m_error = QString::fromLatin1("Add/Declare function requires a complex/container type or a root tag as parent"
                                       ", was=%1").arg(tagFromElement(topElement));
         return false;
@@ -2510,7 +2524,7 @@ bool TypeSystemParser::parseAddFunction(const ConditionalStreamReader &,
 bool TypeSystemParser::parseProperty(const ConditionalStreamReader &, StackElement topElement,
                                      QXmlStreamAttributes *attributes)
 {
-    if ((topElement & StackElement::ComplexTypeEntryMask) == 0) {
+    if (!isComplexTypeEntry(topElement)) {
         m_error = QString::fromLatin1("Add property requires a complex type as parent"
                                       ", was=%1").arg(tagFromElement(topElement));
         return false;
@@ -2545,7 +2559,10 @@ bool TypeSystemParser::parseModifyFunction(const ConditionalStreamReader &reader
                                   StackElement topElement,
                                   QXmlStreamAttributes *attributes)
 {
-    if (!(topElement & StackElement::ComplexTypeEntryMask)) {
+    const bool validParent = isComplexTypeEntry(topElement)
+        || topElement == StackElement::TypedefTypeEntry
+        || topElement == StackElement::FunctionTypeEntry;
+    if (!validParent) {
         m_error = QString::fromLatin1("Modify function requires complex type as parent"
                                       ", was=%1").arg(tagFromElement(topElement));
         return false;
@@ -2809,7 +2826,7 @@ bool TypeSystemParser::parseInjectCode(const ConditionalStreamReader &,
                               StackElement topElement,
                               QXmlStreamAttributes *attributes)
 {
-    if (!(topElement & StackElement::ComplexTypeEntryMask)
+    if (!isComplexTypeEntry(topElement)
         && (topElement != StackElement::AddFunction)
         && (topElement != StackElement::ModifyFunction)
         && (topElement != StackElement::Root)) {
@@ -2880,8 +2897,11 @@ bool TypeSystemParser::parseInclude(const ConditionalStreamReader &,
     }
 
     Include inc(location, fileName);
-    if (topElement
-        & (StackElement::ComplexTypeEntryMask | StackElement::PrimitiveTypeEntry)) {
+    if (isComplexTypeEntry(topElement)
+        || topElement == StackElement::PrimitiveTypeEntry
+        || topElement == StackElement::ContainerTypeEntry
+        || topElement == StackElement::SmartPointerTypeEntry
+        || topElement == StackElement::TypedefTypeEntry) {
         entry->setInclude(inc);
     } else if (topElement == StackElement::ExtraIncludes) {
         entry->addExtraInclude(inc);
@@ -3033,10 +3053,8 @@ bool TypeSystemParser::startElement(const ConditionalStreamReader &reader, Stack
         return true;
     }
 
-    if ((element & StackElement::TypeEntryMask) != 0
-        || element == StackElement::Root) {
+    if (isTypeEntry(element) || element == StackElement::Root)
         m_contextStack.push(StackElementContextPtr(new StackElementContext()));
-    }
 
     if (m_contextStack.isEmpty()) {
         m_error = msgNoRootTypeSystemEntry();
@@ -3046,7 +3064,7 @@ bool TypeSystemParser::startElement(const ConditionalStreamReader &reader, Stack
     const auto &top = m_contextStack.top();
     const StackElement topElement = m_stack.value(m_stack.size() - 2, StackElement::None);
 
-    if (element & StackElement::TypeEntryMask) {
+    if (isTypeEntry(element)) {
         QString name;
         if (element != StackElement::FunctionTypeEntry) {
             const int nameIndex = indexOfAttribute(attributes, nameAttribute());
@@ -3242,7 +3260,7 @@ bool TypeSystemParser::startElement(const ConditionalStreamReader &reader, Stack
             }
 
             const auto topParent = m_stack.value(m_stack.size() - 3, StackElement::None);
-            if ((topParent & StackElement::TypeEntryMask) != 0) {
+            if (isTypeEntry(topParent)) {
                 const int replaceIndex = indexOfAttribute(attributes, replaceAttribute());
                 const bool replace = replaceIndex == -1
                     || convertBoolean(attributes.takeAt(replaceIndex).value(),
diff --git a/sources/shiboken6/ApiExtractor/typesystemparser.h b/sources/shiboken6/ApiExtractor/typesystemparser.h
index d3fbd18cf..011521bc5 100644
--- a/sources/shiboken6/ApiExtractor/typesystemparser.h
+++ b/sources/shiboken6/ApiExtractor/typesystemparser.h
@@ -46,77 +46,77 @@ class TypeSystemEntityResolver;
 class TypeDatabase;
 enum class ParserState;
 
-enum class StackElement : uint64_t {
-            None = 0x0,
+enum class StackElement {
+            None,
 
-            // Type tags (0x1, ... , 0xff)
-            ObjectTypeEntry             = 0x1,
-            ValueTypeEntry              = 0x2,
-            InterfaceTypeEntry          = 0x3,
-            NamespaceTypeEntry          = 0x4,
-            ComplexTypeEntryMask        = 0x7,
+            // Type tags
+            ObjectTypeEntry,
+            FirstTypeEntry = ObjectTypeEntry,
+            ValueTypeEntry,
+            InterfaceTypeEntry,
+            NamespaceTypeEntry,
+            LastComplexTypeEntry = NamespaceTypeEntry,
 
-            // Non-complex type tags (0x8, 0x9, ... , 0xf)
-            PrimitiveTypeEntry          = 0x8,
-            EnumTypeEntry               = 0x9,
-            ContainerTypeEntry          = 0xa,
-            FunctionTypeEntry           = 0xb,
-            CustomTypeEntry             = 0xc,
-            SmartPointerTypeEntry       = 0xd,
-            TypedefTypeEntry            = 0xe,
-            TypeEntryMask               = 0xf,
+            // Non-complex type tags
+            PrimitiveTypeEntry,
+            EnumTypeEntry,
+            ContainerTypeEntry,
+            FunctionTypeEntry,
+            CustomTypeEntry,
+            SmartPointerTypeEntry,
+            TypedefTypeEntry,
+            LastTypeEntry = TypedefTypeEntry,
 
             // Documentation tags
-            InjectDocumentation         = 0x10,
-            ModifyDocumentation         = 0x20,
-            DocumentationMask           = 0xf0,
+            InjectDocumentation,
+            FirstDocumentation = InjectDocumentation,
+            ModifyDocumentation,
+            LastDocumentation = ModifyDocumentation,
 
-            // Simple tags (0x100, 0x200, ... , 0xf00)
-            ExtraIncludes               = 0x0100,
-            Include                     = 0x0200,
-            ModifyFunction              = 0x0300,
-            ModifyField                 = 0x0400,
-            Root                        = 0x0500,
-            SuppressedWarning           = 0x0900,
-            Rejection                   = 0x0a00,
-            LoadTypesystem              = 0x0b00,
-            RejectEnumValue             = 0x0c00,
-            Template                    = 0x0d00,
-            InsertTemplate              = 0x0e00,
-            Replace                     = 0x0f00,
-            AddFunction                 = 0x1000,
-            DeclareFunction             = 0x1100,
-            NativeToTarget              = 0x1200,
-            TargetToNative              = 0x1300,
-            AddConversion               = 0x1400,
-            SystemInclude               = 0x1500,
-            Property                    = 0x1600,
-            SimpleMask                  = 0x3f00,
+            // Simple tags
+            ExtraIncludes,
+            Include,
+            ModifyFunction,
+            ModifyField,
+            Root,
+            SuppressedWarning,
+            Rejection,
+            LoadTypesystem,
+            RejectEnumValue,
+            Template,
+            InsertTemplate,
+            Replace,
+            AddFunction,
+            DeclareFunction,
+            NativeToTarget,
+            TargetToNative,
+            AddConversion,
+            SystemInclude,
+            Property,
 
-            // Code snip tags (0x1000, 0x2000, ... , 0xf000)
-            InjectCode                  = 0x4000,
+            // Code snip tags
+            InjectCode,
 
-            // Function modifier tags (0x010000, 0x020000, ... , 0xf00000)
-            Rename                      = 0x040000, // (modify-argument)
-            ModifyArgument              = 0x080000,
-            Thread                      = 0x100000,
-            FunctionModifiers           = 0xff0000,
+            // Function modifier tags
+            Rename, // (modify-argument)
+            ModifyArgument,
+            Thread,
 
-            // Argument modifier tags (0x01000000 ... 0xf0000000)
-            ConversionRule              = 0x01000000,
-            ReplaceType                 = 0x02000000,
-            ReplaceDefaultExpression    = 0x04000000,
-            RemoveArgument              = 0x08000000,
-            DefineOwnership             = 0x10000000,
-            RemoveDefaultExpression     = 0x20000000,
-            NoNullPointers              = 0x40000000,
-            ReferenceCount              = 0x80000000,
-            ParentOwner                 = 0x90000000,
-            Array                       = 0xA0000000,
-            ArgumentModifiers           = 0xff000000,
+            // Argument modifier tags
+            ConversionRule,
+            ReplaceType,
+            ReplaceDefaultExpression,
+            RemoveArgument,
+            DefineOwnership,
+            RemoveDefaultExpression,
+            NoNullPointers,
+            ReferenceCount,
+            ParentOwner,
+            Array,
+            ArgumentModifiers,
 
-            ImportFile                 = 0x100000000,
-            Unimplemented              = 0x200000000
+            ImportFile,
+            Unimplemented
 };
 
 inline uint64_t operator&(StackElement s1, StackElement s2)