[interop] refactor the IR details provider to avoid the visitor in IRGen

Author: hyp

include/swift/IRGen/SwiftIRDetailsCollector.h renamed to include/swift/IRGen/SwiftIRDetailsProvider.h

@@ -23,39 +23,27 @@ class NominalTypeDecl;
 class IRGenOptions;
 class SILModule;
 
+class IRDetailsProviderImpl;
+
 /// An abstract interface provided to \c IRDetailsVisitor that provides access
 /// to the queries that can be performed on declarations to get their various
 /// ABI details.
 class IRDetailsProvider {
 public:
-  virtual ~IRDetailsProvider() {}
+  IRDetailsProvider(const IRGenOptions &opts, SILModule &SILMod);
+  ~IRDetailsProvider();
 
   using SizeType = uint64_t;
 
   /// Returns the size and alignment for the given type, or \c None if the type
   /// is not a fixed layout type.
-  virtual llvm::Optional<std::pair<SizeType, SizeType>>
-  getTypeSizeAlignment(const NominalTypeDecl *TD) = 0;
-};
+  llvm::Optional<std::pair<SizeType, SizeType>>
+  getTypeSizeAlignment(const NominalTypeDecl *TD);
 
-/// A visitor interface that should be implemented by clients that want to
-/// collect information about ABI of Swift declaration, e.g. the layout of
-/// types.
-class IRDetailsVisitor {
-public:
-  virtual ~IRDetailsVisitor() {}
-  virtual void visitTypeDecl(const NominalTypeDecl *TD,
-                             IRDetailsProvider &irDetails) = 0;
+private:
+  std::unique_ptr<IRDetailsProviderImpl> impl;
 };
 
-/// Gathers ABI details for Swift declarations by inspecting the LLVM IR that is
-/// going to be generated for the given SIL module.
-///
-/// The clients should provide a custom \c IRDetailsVisitor implementation to
-/// collect the details they're interested in.
-void collectSwiftIRDetails(const IRGenOptions &opts, SILModule &SILMod,
-                           IRDetailsVisitor &visitor);
-
 } // namespace swift
 
 #endif

lib/IRGen/CMakeLists.txt

@@ -55,7 +55,7 @@ add_swift_host_library(swiftIRGen STATIC
   MetadataRequest.cpp
   Outlining.cpp
   StructLayout.cpp
-  SwiftIRDetailsCollector.cpp
+  SwiftIRDetailsProvider.cpp
   SwiftTargetInfo.cpp
   TypeLayout.cpp
   TypeLayoutDumper.cpp

lib/IRGen/SwiftIRDetailsCollector.cpp

@@ -0,0 +1,66 @@
+//===--- SwiftIRDetailsCollector.cpp - Get ABI details for 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 "swift/IRGen/SwiftIRDetailsProvider.h"
+#include "FixedTypeInfo.h"
+#include "GenType.h"
+#include "IRGen.h"
+#include "IRGenModule.h"
+
+#include "swift/AST/ASTContext.h"
+#include "swift/AST/ASTMangler.h"
+#include "swift/AST/IRGenOptions.h"
+#include "swift/AST/Types.h"
+#include "swift/SIL/SILModule.h"
+
+#include <vector>
+
+using namespace swift;
+using namespace irgen;
+
+namespace swift {
+
+class IRDetailsProviderImpl {
+public:
+  using SizeType = IRDetailsProvider::SizeType;
+
+  IRDetailsProviderImpl(const IRGenOptions &opts, SILModule &SILMod)
+      : IRGen(opts, SILMod), IGM(IRGen, IRGen.createTargetMachine()) {}
+
+  llvm::Optional<std::pair<SizeType, SizeType>>
+  getTypeSizeAlignment(const NominalTypeDecl *TD) {
+    auto *TI = &IGM.getTypeInfoForUnlowered(TD->getDeclaredTypeInContext());
+    auto *fixedTI = dyn_cast<FixedTypeInfo>(TI);
+    if (!fixedTI)
+      return None;
+    return std::make_pair(fixedTI->getFixedSize().getValue(),
+                          fixedTI->getFixedAlignment().getValue());
+  }
+
+private:
+  IRGenerator IRGen;
+  IRGenModule IGM;
+};
+
+} // namespace swift
+
+IRDetailsProvider::IRDetailsProvider(const IRGenOptions &opts,
+                                     SILModule &SILMod)
+    : impl(std::make_unique<IRDetailsProviderImpl>(opts, SILMod)) {}
+
+IRDetailsProvider::~IRDetailsProvider() {}
+
+llvm::Optional<
+    std::pair<IRDetailsProvider::SizeType, IRDetailsProvider::SizeType>>
+IRDetailsProvider::getTypeSizeAlignment(const NominalTypeDecl *TD) {
+  return impl->getTypeSizeAlignment(TD);
+}

lib/IRGen/SwiftIRDetailsProvider.cpp

@@ -23,8 +23,8 @@ namespace clang_translation {
 
 /// Returns true if the given declaration should be exposed in the generated
 /// Objective-C/C/C++ header, as depending on the specified output language.
-bool shouldExpose(const ValueDecl *VD, OutputLanguageMode outputLang,
-                  AccessLevel minRequiredAccess) {
+inline bool shouldExpose(const ValueDecl *VD, OutputLanguageMode outputLang,
+                         AccessLevel minRequiredAccess) {
   return !VD->isInvalid() &&
          (outputLang == OutputLanguageMode::Cxx
               ? cxx_translation::isVisibleToCxx(VD, minRequiredAccess)
@@ -35,7 +35,7 @@ bool shouldExpose(const ValueDecl *VD, OutputLanguageMode outputLang,
 /// Returns true if the given declaration should be exposed in generated
 /// Objective-C/C/C++ header, regardless of what language the declaration is
 /// exposed to.
-bool shouldExpose(const ValueDecl *VD, AccessLevel minRequiredAccess) {
+inline bool shouldExpose(const ValueDecl *VD, AccessLevel minRequiredAccess) {
   return shouldExpose(VD, OutputLanguageMode::ObjC, minRequiredAccess) ||
          shouldExpose(VD, OutputLanguageMode::Cxx, minRequiredAccess);
 }

lib/PrintAsClang/ExposedDeclFilter.h

@@ -12,10 +12,12 @@
 
 #include "swift/PrintAsClang/SwiftToClangInteropContext.h"
 
+#include "ExposedDeclFilter.h"
 #include "SwiftToClangInteropContextImpl.h"
 
 #include "swift/AST/Decl.h"
-#include "swift/IRGen/SwiftIRDetailsCollector.h"
+#include "swift/IRGen/SwiftIRDetailsProvider.h"
+#include "swift/SIL/SILModule.h"
 #include "llvm/ADT/DenseMap.h"
 
 using namespace swift;
@@ -27,20 +29,21 @@ SwiftToClangInteropContext::~SwiftToClangInteropContext() {}
 
 void SwiftToClangInteropContext::collectSwiftIRGenDetails(
     const IRGenOptions &opts, SILModule &SILMod) {
-  class IRABICollector : public IRDetailsVisitor {
-  public:
-    void visitTypeDecl(const NominalTypeDecl *TD,
-                       IRDetailsProvider &irDetails) override {
-      if (const auto *SD = dyn_cast<StructDecl>(TD)) {
-        if (auto typeInfo = irDetails.getTypeSizeAlignment(TD))
-          impl.addStructDeclInfo(SD, {typeInfo->first, typeInfo->second});
-      }
-    }
+  ModuleDecl &M = *SILMod.getSwiftModule();
+
+  // Gather the declarations that are exposed to clang.
+  SmallVector<Decl *, 64> decls;
+  M.getTopLevelDecls(decls);
 
-    IRABICollector(SwiftToClangInteropContextImpl &impl) : impl(impl) {}
+  IRDetailsProvider irDetails(opts, SILMod);
 
-    SwiftToClangInteropContextImpl &impl;
-  };
-  IRABICollector visitor(*impl);
-  collectSwiftIRDetails(opts, SILMod, visitor);
+  for (auto decl : decls) {
+    const auto *VD = dyn_cast<ValueDecl>(decl);
+    if (!VD || !clang_translation::shouldExpose(VD, AccessLevel::Public))
+      continue;
+    if (const auto *SD = dyn_cast<StructDecl>(VD)) {
+      if (auto typeInfo = irDetails.getTypeSizeAlignment(SD))
+        impl->addStructDeclInfo(SD, {typeInfo->first, typeInfo->second});
+    }
+  }
 }

lib/PrintAsClang/SwiftToClangInteropContext.cpp

@@ -13,7 +13,7 @@
 #ifndef SWIFT_PRINTASCLANG_SWIFTTOCLANGINTEROPCONTEXTIMPL_H
 #define SWIFT_PRINTASCLANG_SWIFTTOCLANGINTEROPCONTEXTIMPL_H
 
-#include "swift/IRGen/SwiftIRDetailsCollector.h"
+#include "swift/IRGen/SwiftIRDetailsProvider.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/Optional.h"
 #include <stdint.h>