genbindings: implement "BecomesNonConstInVersion" quirk support

cmd/genbindings/clang2il.go

@@ -458,7 +458,7 @@ nextMethod:
 
 			// Once all processing is complete, pass to exceptions for final decision
 
-			if err := AllowMethod(mm); err != nil {
+			if err := AllowMethod(ret.ClassName, mm); err != nil {
 				if errors.Is(err, ErrTooComplex) {
 					log.Printf("Skipping method %q with complex type", mm.MethodName)
 					continue nextMethod
@@ -468,6 +468,8 @@ nextMethod:
 				return CppClass{}, err
 			}
 
+			ApplyQuirks(ret.ClassName, &mm)
+
 			ret.Methods = append(ret.Methods, mm)
 
 		default:

cmd/genbindings/config-allowlist.go

@@ -179,7 +179,7 @@ func AllowSignal(mm CppMethod) bool {
 	}
 }
 
-func AllowMethod(mm CppMethod) error {
+func AllowMethod(className string, mm CppMethod) error {
 
 	for _, p := range mm.Parameters {
 		if strings.HasSuffix(p.ParameterType, "Private") {
@@ -395,3 +395,9 @@ func LinuxWindowsCompatCheck(p CppParameter) bool {
 	}
 	return false
 }
+
+func ApplyQuirks(className string, mm *CppMethod) {
+	if className == "QArrayData" && mm.MethodName == "needsDetach" && mm.IsConst {
+		mm.BecomesNonConstInVersion = addr("6.7")
+	}
+}

cmd/genbindings/emitcabi.go

@@ -703,6 +703,23 @@ func emitBindingCpp(src *CppParsedHeader, filename string) (string, error) {
 					m.ReturnType.RenderTypeCabi(),
 				))
 
+			} else if m.BecomesNonConstInVersion != nil {
+
+				nonConstCallTarget := "const_cast<" + cClassName + "*>(self)->" + m.CppCallTarget() + "(" + forwarding + ")"
+
+				ret.WriteString("" +
+					m.ReturnType.RenderTypeCabi() + " " + cClassName + "_" + m.SafeMethodName() + "(" + emitParametersCabi(m, ifv(m.IsConst, "const ", "")+cClassName+"*") + ") {\n" +
+					preamble + "\n" +
+					"// This method was changed from const to non-const in Qt " + *m.BecomesNonConstInVersion + "\n" +
+					"#if QT_VERSION < QT_VERSION_CHECK(" + strings.Replace(*m.BecomesNonConstInVersion, `.`, `,`, -1) + ",0)\n" +
+					emitAssignCppToCabi("\treturn ", m.ReturnType, callTarget) +
+					"#else\n" +
+					emitAssignCppToCabi("\treturn ", m.ReturnType, nonConstCallTarget) +
+					"#endif\n" +
+					"}\n" +
+					"\n",
+				)
+
 			} else {
 
 				ret.WriteString(fmt.Sprintf(

cmd/genbindings/intermediate.go

@@ -209,7 +209,10 @@ type CppMethod struct {
 	IsSignal           bool
 	IsConst            bool
 	HiddenParams       []CppParameter // Populated if there is an overload with more parameters
+
+	// Special quirks
 	LinuxOnly                bool
+	BecomesNonConstInVersion *string // "6,7"
 }
 
 func (m CppMethod) CppCallTarget() string {

cmd/genbindings/util.go

@@ -34,3 +34,7 @@ func ifv[T any](condition bool, trueval T, falseval T) T {
 	}
 	return falseval
 }
+
+func addr[T any](s T) *T {
+	return &s
+}