[interop][SwiftToCxx] handle Swift tuples are unsupported types for now

Author: hyp

lib/IRGen/IRABIDetailsProvider.cpp

@@ -135,6 +135,16 @@ class IRABIDetailsProviderImpl {
     if (silFuncType->getLanguage() != SILFunctionLanguage::Swift)
       return None;
 
+    // FIXME: Tuple parameter mapping support.
+    llvm::SmallVector<const ParamDecl *, 8> silParamMapping;
+    for (auto param : *fd->getParameters()) {
+      if (auto *tuple =
+              param->getType()->getDesugaredType()->getAs<TupleType>()) {
+        if (tuple->getNumElements() > 0)
+          return None;
+      }
+    }
+
     auto funcPointerKind =
         FunctionPointerKind(FunctionPointerKind::BasicKind::Function);
 

lib/PrintAsClang/PrintClangFunction.cpp

@@ -208,8 +208,9 @@ class CFunctionSignatureTypePrinter
   ClangRepresentation visitTupleType(TupleType *TT,
                                      Optional<OptionalTypeKind> optionalKind,
                                      bool isInOutParam) {
-    assert(TT->getNumElements() == 0);
-    // FIXME: Handle non-void type.
+    if (TT->getNumElements() > 0)
+      // FIXME: Handle non-void type.
+      return ClangRepresentation::unsupported;
     os << "void";
     return ClangRepresentation::representable;
   }

test/Interop/SwiftToCxx/unsupported/unsupported-types-in-cxx.swift

@@ -0,0 +1,12 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend %s -typecheck -module-name Functions -clang-header-expose-public-decls -emit-clang-header-path %t/functions.h
+// RUN: %FileCheck %s < %t/functions.h
+
+// RUN: %check-interop-cxx-header-in-clang(%t/functions.h)
+
+// CHECK:     takesFloat
+// CHECK-NOT: takesTuple
+
+public func takesFloat(_ x: Float) {}
+
+public func takesTuple(_ x: (Float, Float)) {}