Added new FixParameterUsageFromComments pass to fix parameter usage through semantic docs.

This pass is not yet enabled by default while it goes through further testing.

src/Generator/Passes/FixParameterUsageFromComments.cs

@@ -0,0 +1,121 @@
+using CppSharp.AST;
+using System;
+
+namespace CppSharp.Passes
+{
+    /// <summary>
+    /// This pass will look through semantic comments (Doxygen) in the source code
+    /// and fix the parameter usage (out or ref) if that information is available.
+    /// </summary>
+    public class FixParameterUsageFromComments : TranslationUnitPass, ICommentVisitor<bool>
+    {
+        Method currentMethod;
+
+        public override bool VisitMethodDecl(Method method)
+        {
+            if (method.Comment == null || method.Comment.FullComment == null)
+                return base.VisitMethodDecl(method);
+
+            Method previousMethod = currentMethod;
+            currentMethod = method;
+
+            var fullComment = method.Comment.FullComment;
+            VisitFull(fullComment);
+
+            currentMethod = previousMethod;
+
+            return base.VisitMethodDecl(method);
+        }
+
+        static ParameterUsage GetParameterUsageFromDirection(ParamCommandComment.PassDirection dir)
+        {
+            switch (dir)
+            {
+                case ParamCommandComment.PassDirection.In:
+                    return ParameterUsage.In;
+                case ParamCommandComment.PassDirection.InOut:
+                    return ParameterUsage.InOut;
+                case ParamCommandComment.PassDirection.Out:
+                    return ParameterUsage.Out;
+            }
+
+            throw new NotSupportedException("Unknown parameter pass direction");
+        }
+
+        public bool VisitParamCommand(ParamCommandComment comment)
+        {
+            if (comment.Direction == ParamCommandComment.PassDirection.In)
+                return false;
+
+            if (!comment.IsParamIndexValid)
+                return false;
+
+            var parameter = currentMethod.Parameters[(int)comment.ParamIndex];
+            parameter.Usage = GetParameterUsageFromDirection(comment.Direction);
+
+            return true;
+        }
+
+        public bool VisitFull(FullComment comment)
+        {
+            foreach (var block in comment.Blocks)
+                block.Visit(this);
+
+            return true;
+        }
+
+        #region Comments visitor stubs
+
+        public bool VisitBlockCommand(BlockCommandComment comment)
+        {
+            return true;
+        }
+
+        public bool VisitParagraphCommand(ParagraphComment comment)
+        {
+            return true;
+        }
+
+        public bool VisitTParamCommand(TParamCommandComment comment)
+        {
+            return true;
+        }
+
+        public bool VisitVerbatimBlock(VerbatimBlockComment comment)
+        {
+            return true;
+        }
+
+        public bool VisitVerbatimLine(VerbatimLineComment comment)
+        {
+            return true;
+        }
+
+        public bool VisitHTMLStartTag(HTMLStartTagComment comment)
+        {
+            return true;
+        }
+
+        public bool VisitHTMLEndTag(HTMLEndTagComment comment)
+        {
+            return true;
+        }
+
+        public bool VisitText(TextComment comment)
+        {
+            return true;
+        }
+
+        public bool VisitInlineCommand(InlineCommandComment comment)
+        {
+            return true;
+        }
+
+        public bool VisitVerbatimBlockLine(VerbatimBlockLineComment comment)
+        {
+            return true;
+        }
+
+        #endregion
+    }
+}