Support explicit enum value declaration in QML

Allow declarations such as:

enum MyEnum {
    Value1 = 1,
    Value2
}

Not all features of C++ enums are supported. Specifically, we don't yet
allow:
* Negative numbers (Value1 = -1)
* Assignment of other values (Value2 = Value1)

Change-Id: I4776f8d86bd0c8688c7dd8b7d4ccb2f72fdfe721
Task-number: QTBUG-14861
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 8 insertions, 3 deletions

diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index b58920d812..a26c80e093 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -45,6 +45,7 @@
 #include <private/qqmljslexer_p.h>
 #include <QCoreApplication>
 #include <QCryptographicHash>
+#include <cmath>
 
 #ifndef V4_BOOTSTRAP
 #include <private/qqmlglobal_p.h>
@@ -740,16 +741,20 @@ bool IRBuilder::visit(QQmlJS::AST::UiEnumDeclaration *node)
     enumeration->enumValues = New<PoolList<EnumValue>>();
 
     QQmlJS::AST::UiEnumMemberList *e = node->members;
-    int i = -1;
     while (e) {
         EnumValue *enumValue = New<EnumValue>();
         QString member = e->member.toString();
         enumValue->nameIndex = registerString(member);
-        enumValue->value = ++i;
-
         if (member.at(0).isLower())
             COMPILE_EXCEPTION(e->memberToken, tr("Enum names must begin with an upper case letter"));
 
+        double part;
+        if (std::modf(e->value, &part) != 0.0)
+            COMPILE_EXCEPTION(e->valueToken, tr("Enum value must be an integer"));
+        if (e->value > std::numeric_limits<qint32>::max() || e->value < std::numeric_limits<qint32>::min())
+            COMPILE_EXCEPTION(e->valueToken, tr("Enum value out of range"));
+        enumValue->value = e->value;
+
         enumValue->location.line = e->memberToken.startLine;
         enumValue->location.column = e->memberToken.startColumn;
         enumeration->enumValues->append(enumValue);