[interop][SwiftToCxx] emit swift type metadata access function declaration for structs

2025-12-14 20:36:38 +01:00 · 2022-06-13 08:04:53 -07:00
parent f6f677f6ca
commit 9254c47b2c
13 changed files with 284 additions and 5 deletions
--- a/lib/PrintAsClang/PrintSwiftToClangCoreScaffold.cpp
+++ b/lib/PrintAsClang/PrintSwiftToClangCoreScaffold.cpp
@@ -0,0 +1,88 @@
+//===--- PrintSwiftToClangCoreScaffold.cpp - Print core decls ---*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "PrintSwiftToClangCoreScaffold.h"
+#include "ClangSyntaxPrinter.h"
+#include "PrimitiveTypeMapping.h"
+#include "SwiftToClangInteropContext.h"
+#include "swift/AST/Decl.h"
+#include "swift/AST/Type.h"
+#include "swift/IRGen/IRABIDetailsProvider.h"
+
+using namespace swift;
+
+static void printKnownCType(Type t, PrimitiveTypeMapping &typeMapping,
+                            raw_ostream &os) {
+  auto info =
+      typeMapping.getKnownCTypeInfo(t->getNominalOrBoundGenericNominal());
+  assert(info.hasValue() && "not a known type");
+  os << info->name;
+  if (info->canBeNullable)
+    os << " _Null_unspecified";
+}
+
+static void printKnownStruct(
+    PrimitiveTypeMapping &typeMapping, raw_ostream &os, StringRef name,
+    const IRABIDetailsProvider::TypeRecordABIRepresentation &typeRecord) {
+  assert(typeRecord.getMembers().size() > 1);
+  os << "struct " << name << " {\n";
+  for (const auto &ty : llvm::enumerate(typeRecord.getMembers())) {
+    os << "  ";
+    printKnownCType(ty.value(), typeMapping, os);
+    os << " _" << ty.index() << ";\n";
+  }
+  os << "};\n";
+}
+
+static void printKnownTypedef(
+    PrimitiveTypeMapping &typeMapping, raw_ostream &os, StringRef name,
+    const IRABIDetailsProvider::TypeRecordABIRepresentation &typeRecord) {
+  assert(typeRecord.getMembers().size() == 1);
+  os << "typedef ";
+  printKnownCType(typeRecord.getMembers()[0], typeMapping, os);
+  os << " " << name << ";\n";
+}
+
+static void printKnownType(
+    PrimitiveTypeMapping &typeMapping, raw_ostream &os, StringRef name,
+    const IRABIDetailsProvider::TypeRecordABIRepresentation &typeRecord) {
+  if (typeRecord.getMembers().size() == 1)
+    return printKnownTypedef(typeMapping, os, name, typeRecord);
+  printKnownStruct(typeMapping, os, name, typeRecord);
+}
+
+static void printTypeMetadataResponseType(SwiftToClangInteropContext &ctx,
+                                          PrimitiveTypeMapping &typeMapping,
+                                          raw_ostream &os) {
+  os << "// Swift type metadata response type.\n";
+  // Print out the type metadata structure.
+  auto funcSig = ctx.getIrABIDetails().getTypeMetadataAccessFunctionSignature();
+  printKnownType(typeMapping, os, "MetadataResponseTy", funcSig.returnType);
+  assert(funcSig.parameterTypes.size() == 1);
+  os << "// Swift type metadata request type.\n";
+  printKnownType(typeMapping, os, "MetadataRequestTy",
+                 funcSig.parameterTypes[0]);
+}
+
+void swift::printSwiftToClangCoreScaffold(SwiftToClangInteropContext &ctx,
+                                          PrimitiveTypeMapping &typeMapping,
+                                          raw_ostream &os) {
+  ClangSyntaxPrinter printer(os);
+  printer.printNamespace("swift", [&](raw_ostream &) {
+    printer.printNamespace(
+        cxx_synthesis::getCxxImplNamespaceName(), [&](raw_ostream &) {
+          printer.printExternC([&](raw_ostream &os) {
+            printTypeMetadataResponseType(ctx, typeMapping, os);
+          });
+        });
+  });
+}