Merge pull request #65930 from artemcm/SeparateClangTargetHandlingForIRGen

artemcm · web-flow · commit 99f545a8ebd1 · 2023-05-16T15:29:02.000-07:00
[Explicit Module Builds] Ensure IRGen uses Swift compiler's target triple when '-clang-target' is set.
diff --git a/include/swift/AST/ClangModuleLoader.h b/include/swift/AST/ClangModuleLoader.h
@@ -124,7 +124,21 @@ class ClangModuleLoader : public ModuleLoader {
   using ModuleLoader::ModuleLoader;
 
 public:
-  virtual clang::TargetInfo &getTargetInfo() const = 0;
+  /// This module loader's Clang instance may be configured with a different
+  /// (higher) OS version than the compilation target itself in order to be able
+  /// to load pre-compiled Clang modules that are aligned with the broader SDK,
+  /// and match the SDK deployment target against which Swift modules are also
+  /// built.
+  ///
+  /// In this case, we must use the Swift compiler's OS version triple when
+  /// performing codegen, and the importer's Clang instance OS version triple
+  /// during module loading. `getModuleAvailabilityTarget` is for module-loading
+  /// clients only, and uses the latter.
+  ///
+  /// (The implementing `ClangImporter` class maintains separate Target info
+  /// for use by IRGen/CodeGen clients)
+  virtual clang::TargetInfo &getModuleAvailabilityTarget() const = 0;
+
   virtual clang::ASTContext &getClangASTContext() const = 0;
   virtual clang::Preprocessor &getClangPreprocessor() const = 0;
   virtual clang::Sema &getClangSema() const = 0;
diff --git a/include/swift/ClangImporter/ClangImporter.h b/include/swift/ClangImporter/ClangImporter.h
@@ -50,6 +50,7 @@ namespace clang {
   class VisibleDeclConsumer;
   class DeclarationName;
   class CompilerInvocation;
+  class TargetOptions;
 namespace tooling {
 namespace dependencies {
   struct ModuleDeps;
@@ -173,7 +174,7 @@ class ClangImporter final : public ClangModuleLoader {
          DWARFImporterDelegate *dwarfImporterDelegate = nullptr);
 
   static std::vector<std::string>
-  getClangArguments(ASTContext &ctx);
+  getClangArguments(ASTContext &ctx, bool ignoreClangTarget = false);
 
   static std::unique_ptr<clang::CompilerInvocation>
   createClangInvocation(ClangImporter *importer,
@@ -445,13 +446,33 @@ class ClangImporter final : public ClangModuleLoader {
       StringRef moduleName,
       ModuleDependencyKind moduleKind,
       ModuleDependenciesCache &cache);
-
-  clang::TargetInfo &getTargetInfo() const override;
+  clang::TargetInfo &getModuleAvailabilityTarget() const override;
   clang::ASTContext &getClangASTContext() const override;
   clang::Preprocessor &getClangPreprocessor() const override;
   clang::Sema &getClangSema() const override;
   const clang::CompilerInstance &getClangInstance() const override;
-  clang::CodeGenOptions &getClangCodeGenOpts() const;
+
+  /// ClangImporter's Clang instance may be configured with a different
+  /// (higher) OS version than the compilation target itself in order to be able
+  /// to load pre-compiled Clang modules that are aligned with the broader SDK,
+  /// and match the SDK deployment target against which Swift modules are also
+  /// built.
+  ///
+  /// In this case, we must use the Swift compiler's OS version triple when
+  /// performing codegen, and the importer's Clang instance OS version triple
+  /// during module loading.
+  ///
+  /// `ClangImporter`'s `Implementation` keeps track of a distinct `TargetInfo`
+  /// and `CodeGenOpts` containers that are meant to be used by clients in
+  /// IRGen. When a separate `-clang-target` is not set, they are defined to be
+  /// copies of the `ClangImporter`'s built-in module-loading Clang instance.
+  /// When `-clang-target` is set, they are configured with the Swift
+  /// compilation's target triple and OS version (but otherwise identical)
+  /// instead. To distinguish IRGen clients from module loading clients,
+  /// `getModuleAvailabilityTarget` should be used instead by module-loading
+  /// clients.
+  clang::TargetInfo &getTargetInfo() const;
+  clang::CodeGenOptions &getCodeGenOpts() const;
 
   std::string getClangModuleHash() const;
 
diff --git a/lib/ClangImporter/ClangImporter.cpp b/lib/ClangImporter/ClangImporter.cpp
@@ -723,11 +723,11 @@ getEmbedBitcodeInvocationArguments(std::vector<std::string> &invocationArgStrs,
 void
 importer::addCommonInvocationArguments(
     std::vector<std::string> &invocationArgStrs,
-    ASTContext &ctx) {
+    ASTContext &ctx, bool ignoreClangTarget) {
   using ImporterImpl = ClangImporter::Implementation;
   llvm::Triple triple = ctx.LangOpts.Target;
   // Use clang specific target triple if given.
-  if (ctx.LangOpts.ClangTarget.has_value()) {
+  if (ctx.LangOpts.ClangTarget.has_value() && !ignoreClangTarget) {
     triple = ctx.LangOpts.ClangTarget.value();
   }
   SearchPathOptions &searchPathOpts = ctx.SearchPathOpts;
@@ -975,7 +975,7 @@ Optional<std::string> ClangImporter::getOrCreatePCH(
 }
 
 std::vector<std::string>
-ClangImporter::getClangArguments(ASTContext &ctx) {
+ClangImporter::getClangArguments(ASTContext &ctx, bool ignoreClangTarget) {
   std::vector<std::string> invocationArgStrs;
   // Clang expects this to be like an actual command line. So we need to pass in
   // "clang" for argv[0]
@@ -996,7 +996,7 @@ ClangImporter::getClangArguments(ASTContext &ctx) {
     getEmbedBitcodeInvocationArguments(invocationArgStrs, ctx);
     break;
   }
-  addCommonInvocationArguments(invocationArgStrs, ctx);
+  addCommonInvocationArguments(invocationArgStrs, ctx, ignoreClangTarget);
   return invocationArgStrs;
 }
 
@@ -1099,15 +1099,6 @@ ClangImporter::create(ASTContext &ctx,
   std::unique_ptr<ClangImporter> importer{
       new ClangImporter(ctx, tracker, dwarfImporterDelegate)};
   auto &importerOpts = ctx.ClangImporterOpts;
-  importer->Impl.ClangArgs = getClangArguments(ctx);
-  ArrayRef<std::string> invocationArgStrs = importer->Impl.ClangArgs;
-  if (importerOpts.DumpClangDiagnostics) {
-    llvm::errs() << "'";
-    llvm::interleave(
-                     invocationArgStrs, [](StringRef arg) { llvm::errs() << arg; },
-                     [] { llvm::errs() << "' '"; });
-    llvm::errs() << "'\n";
-  }
 
   if (isPCHFilenameExtension(importerOpts.BridgingHeader)) {
     importer->Impl.setSinglePCHImport(importerOpts.BridgingHeader);
@@ -1147,6 +1138,15 @@ ClangImporter::create(ASTContext &ctx,
 
   // Create a new Clang compiler invocation.
   {
+    importer->Impl.ClangArgs = getClangArguments(ctx);
+    ArrayRef<std::string> invocationArgStrs = importer->Impl.ClangArgs;
+    if (importerOpts.DumpClangDiagnostics) {
+      llvm::errs() << "'";
+      llvm::interleave(
+                       invocationArgStrs, [](StringRef arg) { llvm::errs() << arg; },
+                       [] { llvm::errs() << "' '"; });
+      llvm::errs() << "'\n";
+    }
     importer->Impl.Invocation = createClangInvocation(
         importer.get(), importerOpts, VFS, invocationArgStrs);
     if (!importer->Impl.Invocation)
@@ -1222,6 +1222,27 @@ ClangImporter::create(ASTContext &ctx,
                          clang::SourceLocation());
   clangDiags.setFatalsAsError(ctx.Diags.getShowDiagnosticsAfterFatalError());
 
+  // Use Clang to configure/save options for Swift IRGen/CodeGen
+  if (ctx.LangOpts.ClangTarget.has_value()) {
+    // If '-clang-target' is set, create a mock invocation with the Swift triple
+    // to configure CodeGen and Target options for Swift compilation.
+    auto swiftTargetClangArgs = getClangArguments(ctx, true);
+    ArrayRef<std::string> invocationArgStrs = swiftTargetClangArgs;
+    auto swiftTargetClangInvocation = createClangInvocation(
+        importer.get(), importerOpts, VFS, invocationArgStrs);
+    if (!swiftTargetClangInvocation)
+      return nullptr;
+    importer->Impl.setSwiftTargetInfo(clang::TargetInfo::CreateTargetInfo(
+        clangDiags, swiftTargetClangInvocation->TargetOpts));
+    importer->Impl.setSwiftCodeGenOptions(new clang::CodeGenOptions(
+        swiftTargetClangInvocation->getCodeGenOpts()));
+  } else {
+    // Just use the existing Invocation's directly
+    importer->Impl.setSwiftTargetInfo(clang::TargetInfo::CreateTargetInfo(
+        clangDiags, importer->Impl.Invocation->TargetOpts));
+    importer->Impl.setSwiftCodeGenOptions(
+        new clang::CodeGenOptions(importer->Impl.Invocation->getCodeGenOpts()));
+  }
 
   // Create the associated action.
   importer->Impl.Action.reset(new ParsingAction(ctx, *importer,
@@ -1880,7 +1901,7 @@ bool ClangImporter::canImportModule(ImportPath::Module modulePath,
   clang::Module *m;
   auto &ctx = Impl.getClangASTContext();
   auto &lo = ctx.getLangOpts();
-  auto &ti = getTargetInfo();
+  auto &ti = getModuleAvailabilityTarget();
 
   auto available = clangModule->isAvailable(lo, ti, r, mh, m);
   if (!available)
@@ -3688,10 +3709,14 @@ StringRef ClangModuleUnit::getLoadedFilename() const {
   return StringRef();
 }
 
-clang::TargetInfo &ClangImporter::getTargetInfo() const {
+clang::TargetInfo &ClangImporter::getModuleAvailabilityTarget() const {
   return Impl.Instance->getTarget();
 }
 
+clang::TargetInfo &ClangImporter::getTargetInfo() const {
+  return *Impl.getSwiftTargetInfo();
+}
+
 clang::ASTContext &ClangImporter::getClangASTContext() const {
   return Impl.getClangASTContext();
 }
@@ -3721,8 +3746,8 @@ clang::Sema &ClangImporter::getClangSema() const {
   return Impl.getClangSema();
 }
 
-clang::CodeGenOptions &ClangImporter::getClangCodeGenOpts() const {
-  return Impl.getClangCodeGenOpts();
+clang::CodeGenOptions &ClangImporter::getCodeGenOpts() const {
+  return *Impl.getSwiftCodeGenOptions();
 }
 
 std::string ClangImporter::getClangModuleHash() const {
diff --git a/lib/ClangImporter/ImporterImpl.h b/lib/ClangImporter/ImporterImpl.h
@@ -39,6 +39,7 @@
 #include "clang/AST/DeclVisitor.h"
 #include "clang/AST/RecursiveASTVisitor.h"
 #include "clang/Basic/IdentifierTable.h"
+#include "clang/Basic/TargetInfo.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Serialization/ModuleFileExtension.h"
 #include "llvm/ADT/APSInt.h"
@@ -588,6 +589,29 @@ class LLVM_LIBRARY_VISIBILITY ClangImporter::Implementation
     return Instance.get();
   }
 
+private:
+  /// The Importer may be configured to load modules of a different OS Version
+  /// than the underlying Swift compilation. This is the `TargetOptions`
+  /// corresponding to the instantiating Swift compilation's triple. These are
+  /// to be used by all IRGen/CodeGen clients of `ClangImporter`.
+  std::unique_ptr<clang::TargetInfo> CodeGenTargetInfo;
+  std::unique_ptr<clang::CodeGenOptions> CodeGenOpts;
+
+public:
+  void setSwiftTargetInfo(clang::TargetInfo *SwiftTargetInfo) {
+    CodeGenTargetInfo.reset(SwiftTargetInfo);
+  }
+  clang::TargetInfo *getSwiftTargetInfo() const {
+    return CodeGenTargetInfo.get();
+  }
+
+  void setSwiftCodeGenOptions(clang::CodeGenOptions *SwiftCodeGenOpts) {
+    CodeGenOpts.reset(SwiftCodeGenOpts);
+  }
+  clang::CodeGenOptions *getSwiftCodeGenOptions() const {
+    return CodeGenOpts.get();
+  }
+
 private:
   /// Generation number that is used for crude versioning.
   ///
@@ -835,7 +859,7 @@ class LLVM_LIBRARY_VISIBILITY ClangImporter::Implementation
     return Instance->getPreprocessor();
   }
   
-  clang::CodeGenOptions &getClangCodeGenOpts() const {
+  clang::CodeGenOptions &getCodeGenOpts() const {
     return Instance->getCodeGenOpts();
   }
 
@@ -1814,7 +1838,8 @@ void getNormalInvocationArguments(std::vector<std::string> &invocationArgStrs,
 
 /// Add command-line arguments common to all imports of Clang code.
 void addCommonInvocationArguments(std::vector<std::string> &invocationArgStrs,
-                                  ASTContext &ctx);
+                                  ASTContext &ctx,
+                                  bool ignoreClangTarget);
 
 /// Finds a particular kind of nominal by looking through typealiases.
 template <typename T>
diff --git a/lib/IRGen/IRGenModule.cpp b/lib/IRGen/IRGenModule.cpp
@@ -86,7 +86,7 @@ static llvm::StructType *createStructType(IRGenModule &IGM,
 }
 
 static clang::CodeGenerator *createClangCodeGenerator(ASTContext &Context,
-                                                 llvm::LLVMContext &LLVMContext,
+                                                      llvm::LLVMContext &LLVMContext,
                                                       const IRGenOptions &Opts,
                                                       StringRef ModuleName,
                                                       StringRef PD) {
@@ -95,7 +95,7 @@ static clang::CodeGenerator *createClangCodeGenerator(ASTContext &Context,
   assert(Importer && "No clang module loader!");
   auto &ClangContext = Importer->getClangASTContext();
 
-  auto &CGO = Importer->getClangCodeGenOpts();
+  auto &CGO = Importer->getCodeGenOpts();
   if (CGO.OpaquePointers) {
     LLVMContext.setOpaquePointers(true);
   } else {
