Merge pull request #344 from Berrysoft/dev/varargs

Add support for varargs.

Author: tannergooding

sources/ClangSharp.PInvokeGenerator/CSharp/CSharpOutputBuilder.VisitDecl.cs

@@ -592,8 +592,11 @@ public void BeginParameter(in ParameterDesc info)
                 _customAttrIsForParameter = false;
 
                 Write(info.Type);
-                Write(' ');
-                Write(info.Name);
+                if (info.Name.Length > 0)
+                {
+                    Write(' ');
+                    Write(info.Name);
+                }
             }
         }
 

sources/ClangSharp.PInvokeGenerator/PInvokeGenerator.VisitDecl.cs

@@ -597,7 +597,9 @@ private void VisitFunctionDecl(FunctionDecl functionDecl)
 
             _outputBuilder.BeginFunctionInnerPrototype(in desc);
 
-            if (isVirtual || (isCxxMethodDecl && !hasBody && cxxMethodDecl.IsInstance))
+            bool needsThis = isVirtual || (isCxxMethodDecl && !hasBody && cxxMethodDecl.IsInstance);
+
+            if (needsThis)
             {
                 Debug.Assert(cxxRecordDecl != null);
 
@@ -636,6 +638,21 @@ private void VisitFunctionDecl(FunctionDecl functionDecl)
 
             Visit(functionDecl.Parameters);
 
+            if (functionDecl.IsVariadic)
+            {
+                if (needsThis || functionDecl.Parameters.Any())
+                {
+                    _outputBuilder.WriteParameterSeparator();
+                }
+                var parameterDesc = new ParameterDesc
+                {
+                    Name = "",
+                    Type = "__arglist"
+                };
+                _outputBuilder.BeginParameter(in parameterDesc);
+                _outputBuilder.EndParameter(in parameterDesc);
+            }
+
             _outputBuilder.EndFunctionInnerPrototype(in desc);
 
             if (hasBody && !isVirtual)
@@ -674,6 +691,15 @@ private void VisitFunctionDecl(FunctionDecl functionDecl)
                         }
                     }
 
+                    if (functionDecl.IsVariadic)
+                    {
+                        if (parameters.Count != 0)
+                        {
+                            outputBuilder.Write(", ");
+                        }
+                        outputBuilder.Write("__arglist");
+                    }
+
                     outputBuilder.Write(')');
 
                     outputBuilder.NeedsSemicolon = true;

sources/ClangSharp.PInvokeGenerator/PInvokeGenerator.cs

@@ -1932,6 +1932,14 @@ private Type[] GetBitfieldCount(RecordDecl recordDecl)
 
         private CallingConvention GetCallingConvention(Cursor cursor, Cursor context, Type type)
         {
+            if (cursor is FunctionDecl functionDecl)
+            {
+                if (functionDecl.IsVariadic)
+                {
+                    return CallingConvention.Cdecl;
+                }
+            }
+
             if (cursor is NamedDecl namedDecl)
             {
                 if (TryGetRemappedValue(namedDecl, _config.WithCallConvs, out var callConv, matchStar: true))

tests/ClangSharp.PInvokeGenerator.UnitTests/Base/FunctionDeclarationDllImportTest.cs

@@ -73,6 +73,9 @@ public abstract class FunctionDeclarationDllImportTest : PInvokeGeneratorTest
         [Test]
         public Task SourceLocationTest() => SourceLocationTestImpl();
 
+        [Test]
+        public Task VarargsTest() => VarargsTestImpl();
+
         protected abstract Task BasicTestImpl();
 
         protected abstract Task ArrayParameterTestImpl();
@@ -106,5 +109,7 @@ public abstract class FunctionDeclarationDllImportTest : PInvokeGeneratorTest
         protected abstract Task WithSetLastErrorStarTestImpl();
 
         protected abstract Task SourceLocationTestImpl();
+
+        protected abstract Task VarargsTestImpl();
     }
 }

tests/ClangSharp.PInvokeGenerator.UnitTests/CSharpCompatibleUnix/FunctionDeclarationDllImportTest.cs

@@ -396,5 +396,7 @@ public static partial class Methods
 
             return ValidateGeneratedCSharpCompatibleUnixBindingsAsync(InputContents, ExpectedOutputContents, PInvokeGeneratorConfigurationOptions.GenerateSourceLocationAttribute);
         }
+
+        protected override Task VarargsTestImpl() => Task.CompletedTask;
     }
 }

tests/ClangSharp.PInvokeGenerator.UnitTests/CSharpCompatibleWindows/FunctionDeclarationDllImportTest.cs

@@ -395,5 +395,24 @@ public static partial class Methods
 
             return ValidateGeneratedCSharpCompatibleWindowsBindingsAsync(InputContents, ExpectedOutputContents, PInvokeGeneratorConfigurationOptions.GenerateSourceLocationAttribute);
         }
+
+        protected override Task VarargsTestImpl()
+        {
+            const string InputContents = @"extern ""C"" void MyFunction(int value, ...);";
+
+            const string ExpectedOutputContents = @"using System.Runtime.InteropServices;
+
+namespace ClangSharp.Test
+{
+    public static partial class Methods
+    {
+        [DllImport(""ClangSharpPInvokeGenerator"", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern void MyFunction(int value, __arglist);
+    }
+}
+";
+
+            return ValidateGeneratedCSharpCompatibleWindowsBindingsAsync(InputContents, ExpectedOutputContents);
+        }
     }
 }

tests/ClangSharp.PInvokeGenerator.UnitTests/CSharpLatestUnix/FunctionDeclarationDllImportTest.cs

@@ -394,5 +394,7 @@ public static partial class Methods
 
             return ValidateGeneratedCSharpLatestUnixBindingsAsync(InputContents, ExpectedOutputContents, PInvokeGeneratorConfigurationOptions.GenerateSourceLocationAttribute);
         }
+
+        protected override Task VarargsTestImpl() => Task.CompletedTask;
     }
 }

tests/ClangSharp.PInvokeGenerator.UnitTests/CSharpLatestWindows/FunctionDeclarationDllImportTest.cs

@@ -394,5 +394,24 @@ public static partial class Methods
 
             return ValidateGeneratedCSharpLatestWindowsBindingsAsync(InputContents, ExpectedOutputContents, PInvokeGeneratorConfigurationOptions.GenerateSourceLocationAttribute);
         }
+
+        protected override Task VarargsTestImpl()
+        {
+            const string InputContents = @"extern ""C"" void MyFunction(int value, ...);";
+
+            const string ExpectedOutputContents = @"using System.Runtime.InteropServices;
+
+namespace ClangSharp.Test
+{
+    public static partial class Methods
+    {
+        [DllImport(""ClangSharpPInvokeGenerator"", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern void MyFunction(int value, __arglist);
+    }
+}
+";
+
+            return ValidateGeneratedCSharpLatestWindowsBindingsAsync(InputContents, ExpectedOutputContents);
+        }
     }
 }

tests/ClangSharp.PInvokeGenerator.UnitTests/XmlCompatibleUnix/FunctionDeclarationDllImportTest.cs

@@ -447,5 +447,7 @@ protected override Task SourceLocationTestImpl()
 
             return ValidateGeneratedXmlCompatibleUnixBindingsAsync(InputContents, ExpectedOutputContents, PInvokeGeneratorConfigurationOptions.GenerateSourceLocationAttribute);
         }
+
+        protected override Task VarargsTestImpl() => Task.CompletedTask;
     }
 }

tests/ClangSharp.PInvokeGenerator.UnitTests/XmlCompatibleWindows/FunctionDeclarationDllImportTest.cs

@@ -447,5 +447,7 @@ protected override Task SourceLocationTestImpl()
 
             return ValidateGeneratedXmlCompatibleWindowsBindingsAsync(InputContents, ExpectedOutputContents, PInvokeGeneratorConfigurationOptions.GenerateSourceLocationAttribute);
         }
+
+        protected override Task VarargsTestImpl() => Task.CompletedTask;
     }
 }