shiboken: Store null enum values

If an enum has a null value, store that on the EnumTypeEntry for
use in Generator::minimalConstructor() as a default value.
Fully qualify scoped enum value type entries for this purpose.

The value can then be used for default values instead of an ugly
static_cast<EnumType>(0).

Task-number: PYSIDE-62
Change-Id: I42cb2ca63fb1da6c795df630ab30bded66aac901
Reviewed-by: Christian Tismer <tismer@stackless.com>

3 files changed, 19 insertions, 2 deletions

diff --git a/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp b/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp
index 251d674a9..c8ff41d91 100644
--- a/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp
+++ b/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp
@@ -960,6 +960,15 @@ AbstractMetaEnum *AbstractMetaBuilderPrivate::traverseEnum(const EnumModelItem &
     metaEnum->setOriginalAttributes(metaEnum->attributes());
 
     // Register all enum values on Type database
+    QString prefix;
+    if (enclosing) {
+        prefix += enclosing->typeEntry()->qualifiedCppName();
+        prefix += colonColon();
+    }
+    if (enumItem->enumKind() == EnumClass) {
+        prefix += enumItem->name();
+        prefix += colonColon();
+    }
     const EnumeratorList &enumerators = enumItem->enumerators();
     for (const EnumeratorModelItem &e : enumerators) {
         QString name;
@@ -967,11 +976,12 @@ AbstractMetaEnum *AbstractMetaBuilderPrivate::traverseEnum(const EnumModelItem &
             name += enclosing->name();
             name += colonColon();
         }
-        name += e->name();
         EnumValueTypeEntry *enumValue =
-            new EnumValueTypeEntry(name, e->stringValue(),
+            new EnumValueTypeEntry(prefix + e->name(), e->stringValue(),
                                    enumTypeEntry, enumTypeEntry->version());
         TypeDatabase::instance()->addType(enumValue);
+        if (e->value().isNullValue())
+            enumTypeEntry->setNullValue(enumValue);
     }
 
     return metaEnum;
diff --git a/sources/shiboken2/ApiExtractor/parser/enumvalue.h b/sources/shiboken2/ApiExtractor/parser/enumvalue.h
index 4905e89ba..ea30c39bb 100644
--- a/sources/shiboken2/ApiExtractor/parser/enumvalue.h
+++ b/sources/shiboken2/ApiExtractor/parser/enumvalue.h
@@ -49,6 +49,7 @@ public:
     Type type() { return m_type; }
     qint64 value() const { return m_value; }
     quint64 unsignedValue() const { return m_unsignedValue; }
+    bool isNullValue() const { return m_type == Signed ? m_value == 0 : m_unsignedValue == 0u; }
 
     void setValue(qint64 v);
     void setUnsignedValue(quint64 v);
diff --git a/sources/shiboken2/ApiExtractor/typesystem.h b/sources/shiboken2/ApiExtractor/typesystem.h
index 26f94e3ee..d892cb3a5 100644
--- a/sources/shiboken2/ApiExtractor/typesystem.h
+++ b/sources/shiboken2/ApiExtractor/typesystem.h
@@ -1067,6 +1067,8 @@ private:
     PrimitiveTypeEntry* m_referencedTypeEntry = nullptr;
 };
 
+class EnumValueTypeEntry;
+
 class EnumTypeEntry : public TypeEntry
 {
 public:
@@ -1088,6 +1090,9 @@ public:
         m_qualifier = q;
     }
 
+    const EnumValueTypeEntry *nullValue() const { return m_nullValue; }
+    void setNullValue(const EnumValueTypeEntry *n) { m_nullValue = n; }
+
     void setFlags(FlagsTypeEntry *flags)
     {
         m_flags = flags;
@@ -1121,6 +1126,7 @@ private:
     QString m_packageName;
     QString m_qualifier;
     QString m_targetLangName;
+    const EnumValueTypeEntry *m_nullValue = nullptr;
 
     QStringList m_rejectedEnums;