Add some support for parsing attributes defined by macros (xoofx#51)

Only basic parsing is performed by this PR but it does allow for
a macro to hold an scoped attribute with arguments.

src/CppAst.Tests/TestAttributes.cs

@@ -196,6 +196,30 @@ struct [[deprecated(""old"")]] TestMessage{
           );
         }
 
+        [Test]
+        public void TestCpp11StructAttributesWithMacro()
+        {
+          ParseAssert(@"
+#define CLASS_ATTRIBUTE [[deprecated]]
+struct CLASS_ATTRIBUTE  Test{
+    int a;
+    int b;
+};", compilation =>
+          {
+            Assert.False(compilation.HasErrors);
+
+            Assert.AreEqual(1, compilation.Classes.Count);
+            Assert.AreEqual(1, compilation.Classes[0].Attributes.Count);
+            {
+              var attr = compilation.Classes[0].Attributes[0];
+              Assert.AreEqual("deprecated", attr.Name);
+            }
+          },
+          // we are using a C++14 attribute because it can be used everywhere
+          new CppParserOptions() { AdditionalArguments = { "-std=c++14" }, ParseAttributes = true }
+        );
+        }
+
         [Test]
         public void TestCpp11VariablesAttributes()
         {

src/CppAst/CppModelBuilder.cs

@@ -1337,6 +1337,41 @@ private List<CppAttribute> ParseFunctionAttributes(CXCursor cursor, string funct
             return attributes;
         }
 
+        private (string, string) GetNameSpaceAndAttribute(string fullAttribute)
+        {
+            string[] colons = { "::" };
+            string[] tokens = fullAttribute.Split(colons, System.StringSplitOptions.None);
+            if (tokens.Length == 2)
+            {
+                return (tokens[0], tokens[1]);
+            }
+            else
+            {
+                return (null, tokens[0]);
+            }
+        }
+
+
+        private (string, string) GetNameAndArguments(string name)
+        {
+            if (name.Contains("("))
+            {
+                Char[] seperator = { '(' };
+                var argumentTokens = name.Split(seperator, 2);
+                var length = argumentTokens[1].LastIndexOf(')');
+                string argument = null;
+                if (length > 0)
+                {
+                    argument = argumentTokens[1].Substring(0, length);
+                }
+                return (argumentTokens[0], argument);
+            }
+            else
+            {
+                return (name, null);
+            }
+        }
+
         private bool ParseAttributes(TokenIterator tokenIt, ref List<CppAttribute> attributes)
         {
             // Parse C++ attributes
@@ -1414,6 +1449,32 @@ private bool ParseAttributes(TokenIterator tokenIt, ref List<CppAttribute> attri
                 return tokenIt.Skip(")"); ;
             }
 
+            // See if we have a macro
+            var value = tokenIt.PeekText();
+            var globalContainer = (CppGlobalDeclarationContainer)_rootContainerContext.DeclarationContainer;
+            var macro = globalContainer.Macros.Find(v => v.Name == value);
+            if (macro != null)
+            {
+                if (macro.Value.StartsWith("[[") && macro.Value.EndsWith("]]"))
+                {
+                    CppAttribute attribute = null;
+                    var fullAttribute = macro.Value.Substring(2, macro.Value.Length - 4);
+                    var (scope, name) = GetNameSpaceAndAttribute(fullAttribute);
+                    var (attributeName, arguments) = GetNameAndArguments(name);
+
+                    attribute = new CppAttribute(attributeName);
+                    attribute.Scope = scope;
+                    attribute.Arguments = arguments;
+
+                    if (attributes == null)
+                    {
+                        attributes = new List<CppAttribute>();
+                    }
+                    attributes.Add(attribute);
+                    tokenIt.Next();
+                    return true;
+                }
+            }
             return false;
         }
 
@@ -2367,4 +2428,4 @@ public CppContainerContext(ICppContainer container)
             public bool IsChildrenVisited;
         }
     }
-}
+}