first commit

internal/winmd/methoddef.go

@@ -0,0 +1,76 @@
+package winmd
+
+import (
+	"github.com/tdakkota/win32metadata/md"
+	"github.com/tdakkota/win32metadata/types"
+)
+
+// GetMethodOverloadName finds and returns the overload attribute for the given method
+func GetMethodOverloadName(ctx *types.Context, methodDef *types.MethodDef) string {
+	cAttrTable := ctx.Table(md.CustomAttribute)
+	for i := uint32(0); i < cAttrTable.RowCount(); i++ {
+		var cAttr types.CustomAttribute
+		if err := cAttr.FromRow(cAttrTable.Row(i)); err != nil {
+			continue
+		}
+
+		// - Parent: The owner of the Attribute must be the given func
+		if cAttrParentTable, _ := cAttr.Parent.Table(); cAttrParentTable != md.MethodDef {
+			continue
+		}
+
+		var parentMethodDef types.MethodDef
+		row, ok := cAttr.Parent.Row(ctx)
+		if !ok {
+			continue
+		}
+		if err := parentMethodDef.FromRow(row); err != nil {
+			continue
+		}
+
+		// does the blob belong to the method we're looking for?
+		if parentMethodDef.Name != methodDef.Name || string(parentMethodDef.Signature) != string(methodDef.Signature) {
+			continue
+		}
+
+		// - Type: the attribute type must be the given type
+		// the cAttr.Type table can be either a MemberRef or a MethodRef.
+		// Since we are looking for a type, we will only consider the MemberRef.
+		if cAttrTypeTable, _ := cAttr.Type.Table(); cAttrTypeTable != md.MemberRef {
+			continue
+		}
+
+		var attrTypeMemberRef types.MemberRef
+		row, ok = cAttr.Type.Row(ctx)
+		if !ok {
+			continue
+		}
+		if err := attrTypeMemberRef.FromRow(row); err != nil {
+			continue
+		}
+
+		// we need to check the MemberRef Class
+		// the value can belong to several tables, but we are only going to check for TypeRef
+		if classTable, _ := attrTypeMemberRef.Class.Table(); classTable != md.TypeRef {
+			continue
+		}
+
+		var attrTypeRef types.TypeRef
+		row, ok = attrTypeMemberRef.Class.Row(ctx)
+		if !ok {
+			continue
+		}
+		if err := attrTypeRef.FromRow(row); err != nil {
+			continue
+		}
+
+		if attrTypeRef.TypeNamespace+"."+attrTypeRef.TypeName == AttributeTypeOverloadAttribute {
+			// Metadata values start with 0x01 0x00 and ends with 0x00 0x00
+			mdVal := cAttr.Value[2 : len(cAttr.Value)-2]
+			// the next value is the length of the string
+			mdVal = mdVal[1:]
+			return string(mdVal)
+		}
+	}
+	return methodDef.Name
+}