Add interface-wide default calling convention

AdvancedDLSupport.Tests/Data/Interfaces/ICallingConventionLibrary.cs

@@ -0,0 +1,38 @@
+//
+//  ICallingConventionLibrary.cs
+//
+//  Copyright (c) 2018 Firwood Software
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+using static System.Runtime.InteropServices.CallingConvention;
+
+#pragma warning disable SA1600, CS1591
+
+namespace AdvancedDLSupport.Tests.Data.Interfaces
+{
+    [NativeSymbols(DefaultCallingConvention = StdCall)]
+    public interface ICallingConventionLibrary
+    {
+        int MultiplyBy5_STD(int num);
+
+        [NativeSymbol(CallingConvention = Cdecl)]
+        int MultiplyBy5(int num);
+    }
+}

AdvancedDLSupport.Tests/Tests/Integration/CallingConventionTests.cs

@@ -0,0 +1,50 @@
+//
+//  CallingConventionTests.cs
+//
+//  Copyright (c) 2018 Firwood Software
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using AdvancedDLSupport.Tests.Data.Interfaces;
+using AdvancedDLSupport.Tests.TestBases;
+
+using Xunit;
+
+#pragma warning disable SA1600, CS1591
+
+namespace AdvancedDLSupport.Tests.Integration
+{
+    public class CallingConventionTests : LibraryTestBase<ICallingConventionLibrary>
+    {
+        private const string LibraryName = "CallingConventionTests";
+
+        public CallingConventionTests()
+            : base(LibraryName)
+        {
+        }
+
+        [Fact]
+        public void StdCallIsDefaultInterfaceConvention()
+        {
+            Assert.Equal(20, Library.MultiplyBy5_STD(4));
+        }
+
+        [Fact]
+        public void NativeSymbolOverrideWorks()
+        {
+            Assert.Equal(20, Library.MultiplyBy5(4));
+        }
+    }
+}

AdvancedDLSupport.Tests/c/CMakeLists.txt

@@ -42,6 +42,7 @@ list(
         GenericDelegateTests
         BooleanMarshallingTests
         SpanMarshallingTests
+		CallingConventionTests
 )
 
 list(

AdvancedDLSupport.Tests/c/src/CallingConventionTests.c

@@ -0,0 +1,12 @@
+#include <stdint.h>
+#include "comp.h"
+
+__declspec(dllexport) int32_t __stdcall MultiplyBy5_STD(int32_t num)
+{
+	return num * 5;
+}
+
+__declspec(dllexport) int32_t MultiplyBy5(int32_t num)
+{
+	return num * 5;
+}

AdvancedDLSupport/Attributes/NativeSymbolAttribute.cs

@@ -49,7 +49,6 @@ public sealed class NativeSymbolAttribute : Attribute
         [PublicAPI]
         public NativeSymbolAttribute([NotNull, CallerMemberName] string entrypoint = "")
         {
-            CallingConvention = CallingConvention.Cdecl;
             Entrypoint = entrypoint;
         }
     }

AdvancedDLSupport/Reflection/IntrospectiveMemberBase.cs

@@ -141,8 +141,14 @@ public string GetNativeEntrypoint()
         /// <inheritdoc />
         public CallingConvention GetNativeCallingConvention()
         {
-            var metadataAttribute = GetCustomAttribute<NativeSymbolAttribute>() ??
-                                    new NativeSymbolAttribute(Name);
+            var metadataAttribute = GetCustomAttribute<NativeSymbolAttribute>();
+
+            if (metadataAttribute == null || metadataAttribute.CallingConvention == default)
+            {
+                NativeSymbolsAttribute attribute = MetadataType.GetCustomAttribute<NativeSymbolsAttribute>();
+
+                return attribute == null || attribute.DefaultCallingConvention == default ? CallingConvention.Cdecl : attribute.DefaultCallingConvention;
+            }
 
             return metadataAttribute.CallingConvention;
         }

AdvancedDLSupport/SymbolTransformation/Attributes/NativeSymbolsAttribute.cs

@@ -18,6 +18,7 @@
 //
 
 using System;
+using System.Runtime.InteropServices;
 using JetBrains.Annotations;
 
 namespace AdvancedDLSupport
@@ -40,6 +41,12 @@ public class NativeSymbolsAttribute : Attribute
         [PublicAPI]
         public SymbolTransformationMethod SymbolTransformationMethod { get; set; }
 
+        /// <summary>
+        /// Gets or sets the default calling convention for symbols of the interface.
+        /// </summary>
+        [PublicAPI]
+        public CallingConvention DefaultCallingConvention { get; set; }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="NativeSymbolsAttribute"/> class.
         /// </summary>