[clang] Hide the TargetOptions pointer from CompilerInvocation (#106271)

This PR hides the reference-counted pointer that holds `TargetOptions`
from the public API of `CompilerInvocation`. This gives
`CompilerInvocation` an exclusive control over the lifetime of this
member, which will eventually be leveraged to implement a copy-on-write
behavior.

There are two clients that currently share ownership of that pointer:

* `TargetInfo` - This was refactored to hold a non-owning reference to
`TargetOptions`. The options object is typically owned by the
`CompilerInvocation` or by the new `CompilerInstance::AuxTargetOpts` for
the auxiliary target. This needed a bit of care in `ASTUnit::Parse()` to
keep the `CompilerInvocation` alive.
* `clangd::PreambleData` - This was refactored to exclusively own the
`TargetOptions` that get moved out of the `CompilerInvocation`.

clang-tools-extra/clangd/Preamble.cpp

@@ -711,7 +711,10 @@ buildPreamble(PathRef FileName, CompilerInvocation CI,
     Result->Marks = CapturedInfo.takeMarks();
     Result->StatCache = StatCache;
     Result->MainIsIncludeGuarded = CapturedInfo.isMainFileIncludeGuarded();
-    Result->TargetOpts = CI.TargetOpts;
+    // Move the options instead of copying them. The invocation doesn't need
+    // them anymore.
+    Result->TargetOpts =
+        std::make_unique<TargetOptions>(std::move(CI.getTargetOpts()));
     if (PreambleCallback) {
       trace::Span Tracer("Running PreambleCallback");
       auto Ctx = CapturedInfo.takeLife();
@@ -932,7 +935,7 @@ void PreamblePatch::apply(CompilerInvocation &CI) const {
   // ParsedASTTest.PreambleWithDifferentTarget.
   // Make sure this is a deep copy, as the same Baseline might be used
   // concurrently.
-  *CI.TargetOpts = *Baseline->TargetOpts;
+  CI.getTargetOpts() = *Baseline->TargetOpts;
 
   // No need to map an empty file.
   if (PatchContents.empty())

clang-tools-extra/clangd/Preamble.h

@@ -103,7 +103,7 @@ struct PreambleData {
   // Target options used when building the preamble. Changes in target can cause
   // crashes when deserializing preamble, this enables consumers to use the
   // same target (without reparsing CompileCommand).
-  std::shared_ptr<TargetOptions> TargetOpts = nullptr;
+  std::unique_ptr<TargetOptions> TargetOpts = nullptr;
   PrecompiledPreamble Preamble;
   std::vector<Diag> Diags;
   // Processes like code completions and go-to-definitions will need #include

clang-tools-extra/clangd/SystemIncludeExtractor.cpp

@@ -256,7 +256,7 @@ bool isValidTarget(llvm::StringRef Triple) {
   DiagnosticsEngine Diags(new DiagnosticIDs, new DiagnosticOptions,
                           new IgnoringDiagConsumer);
   llvm::IntrusiveRefCntPtr<TargetInfo> Target =
-      TargetInfo::CreateTargetInfo(Diags, TargetOpts);
+      TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
   return bool(Target);
 }
 

clang-tools-extra/modularize/ModularizeUtilities.cpp

@@ -53,7 +53,7 @@ ModularizeUtilities::ModularizeUtilities(std::vector<std::string> &InputPaths,
       Diagnostics(
           new DiagnosticsEngine(DiagIDs, DiagnosticOpts.get(), &DC, false)),
       TargetOpts(new ModuleMapTargetOptions()),
-      Target(TargetInfo::CreateTargetInfo(*Diagnostics, TargetOpts)),
+      Target(TargetInfo::CreateTargetInfo(*Diagnostics, *TargetOpts)),
       FileMgr(new FileManager(FileSystemOpts)),
       SourceMgr(new SourceManager(*Diagnostics, *FileMgr, false)), HSOpts(),
       HeaderInfo(new HeaderSearch(HSOpts, *SourceMgr, *Diagnostics, *LangOpts,

clang/include/clang/Basic/TargetInfo.h

@@ -224,7 +224,7 @@ enum OpenCLTypeKind : uint8_t {
 ///
 class TargetInfo : public TransferrableTargetInfo,
                    public RefCountedBase<TargetInfo> {
-  std::shared_ptr<TargetOptions> TargetOpts;
+  TargetOptions *TargetOpts;
   llvm::Triple Triple;
 protected:
   // Target values set by the ctor of the actual target implementation.  Default
@@ -310,10 +310,9 @@ public:
   ///
   /// \param Opts - The options to use to initialize the target. The target may
   /// modify the options to canonicalize the target feature information to match
-  /// what the backend expects.
-  static TargetInfo *
-  CreateTargetInfo(DiagnosticsEngine &Diags,
-                   const std::shared_ptr<TargetOptions> &Opts);
+  /// what the backend expects. These must outlive the returned TargetInfo.
+  static TargetInfo *CreateTargetInfo(DiagnosticsEngine &Diags,
+                                      TargetOptions &Opts);
 
   virtual ~TargetInfo();
 

clang/include/clang/Frontend/ASTUnit.h

@@ -143,6 +143,10 @@ private:
   /// Parse available.
   std::shared_ptr<CompilerInvocation> CCInvocation;
 
+  /// Optional owned invocation, just used to keep the invocation alive for the
+  /// members initialized in transferASTDataFromCompilerInstance.
+  std::shared_ptr<CompilerInvocation> ModifiedInvocation;
+
   /// Fake module loader: the AST unit doesn't need to load any modules.
   TrivialModuleLoader ModuleLoader;
 

clang/include/clang/Frontend/CompilerInstance.h

@@ -88,6 +88,9 @@ class CompilerInstance : public ModuleLoader {
   /// The target being compiled for.
   IntrusiveRefCntPtr<TargetInfo> Target;
 
+  /// Options for the auxiliary target.
+  std::unique_ptr<TargetOptions> AuxTargetOpts;
+
   /// Auxiliary Target info.
   IntrusiveRefCntPtr<TargetInfo> AuxTarget;
 

clang/include/clang/Frontend/CompilerInvocation.h

@@ -268,7 +268,6 @@ public:
   /// Base class internals.
   /// @{
   using CompilerInvocationBase::LangOpts;
-  using CompilerInvocationBase::TargetOpts;
   std::shared_ptr<LangOptions> getLangOptsPtr() { return LangOpts; }
   /// @}
 

clang/lib/Basic/Targets.cpp

@@ -774,9 +774,10 @@ std::unique_ptr<TargetInfo> AllocateTarget(const llvm::Triple &Triple,
 using namespace clang::targets;
 /// CreateTargetInfo - Return the target info object for the specified target
 /// options.
-TargetInfo *
-TargetInfo::CreateTargetInfo(DiagnosticsEngine &Diags,
-                             const std::shared_ptr<TargetOptions> &Opts) {
+TargetInfo *TargetInfo::CreateTargetInfo(DiagnosticsEngine &Diags,
+                                         TargetOptions &OptsRef) {
+  TargetOptions *Opts = &OptsRef;
+
   llvm::Triple Triple(llvm::Triple::normalize(Opts->Triple));
 
   // Construct the target

clang/lib/Frontend/ASTUnit.cpp

@@ -615,7 +615,7 @@ public:
 
     this->TargetOpts = std::make_shared<TargetOptions>(TargetOpts);
     Target =
-        TargetInfo::CreateTargetInfo(PP.getDiagnostics(), this->TargetOpts);
+        TargetInfo::CreateTargetInfo(PP.getDiagnostics(), *this->TargetOpts);
 
     updated();
     return false;
@@ -1499,6 +1499,10 @@ void ASTUnit::transferASTDataFromCompilerInstance(CompilerInstance &CI) {
     Target = &CI.getTarget();
   Reader = CI.getASTReader();
   HadModuleLoaderFatalFailure = CI.hadModuleLoaderFatalFailure();
+  if (Invocation != CI.getInvocationPtr()) {
+    // This happens when Parse creates a copy of \c Invocation to modify.
+    ModifiedInvocation = CI.getInvocationPtr();
+  }
 }
 
 StringRef ASTUnit::getMainFileName() const {

clang/lib/Frontend/ChainedIncludesSource.cpp

@@ -127,7 +127,7 @@ IntrusiveRefCntPtr<ExternalSemaSource> clang::createChainedIncludesSource(
     Clang->setInvocation(std::move(CInvok));
     Clang->setDiagnostics(Diags.get());
     Clang->setTarget(TargetInfo::CreateTargetInfo(
-        Clang->getDiagnostics(), Clang->getInvocation().TargetOpts));
+        Clang->getDiagnostics(), Clang->getInvocation().getTargetOpts()));
     Clang->createFileManager();
     Clang->createSourceManager(Clang->getFileManager());
     Clang->createPreprocessor(TU_Prefix);

clang/lib/Frontend/CompilerInstance.cpp

@@ -110,7 +110,7 @@ void CompilerInstance::setAuxTarget(TargetInfo *Value) { AuxTarget = Value; }
 bool CompilerInstance::createTarget() {
   // Create the target instance.
   setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(),
-                                         getInvocation().TargetOpts));
+                                         getInvocation().getTargetOpts()));
   if (!hasTarget())
     return false;
 
@@ -119,14 +119,14 @@ bool CompilerInstance::createTarget() {
   if (!getAuxTarget() &&
       (getLangOpts().CUDA || getLangOpts().isTargetDevice()) &&
       !getFrontendOpts().AuxTriple.empty()) {
-    auto TO = std::make_shared<TargetOptions>();
+    auto &TO = AuxTargetOpts = std::make_unique<TargetOptions>();
     TO->Triple = llvm::Triple::normalize(getFrontendOpts().AuxTriple);
     if (getFrontendOpts().AuxTargetCPU)
       TO->CPU = *getFrontendOpts().AuxTargetCPU;
     if (getFrontendOpts().AuxTargetFeatures)
       TO->FeaturesAsWritten = *getFrontendOpts().AuxTargetFeatures;
     TO->HostTriple = getTarget().getTriple().str();
-    setAuxTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), TO));
+    setAuxTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), *TO));
   }
 
   if (!getTarget().hasStrictFP() && !getLangOpts().ExpStrictFP) {

clang/lib/Interpreter/Interpreter.cpp

@@ -125,7 +125,7 @@ CreateCI(const llvm::opt::ArgStringList &Argv) {
   Clang->getPreprocessorOpts().addRemappedFile("<<< inputs >>>", MB);
 
   Clang->setTarget(TargetInfo::CreateTargetInfo(
-      Clang->getDiagnostics(), Clang->getInvocation().TargetOpts));
+      Clang->getDiagnostics(), Clang->getInvocation().getTargetOpts()));
   if (!Clang->hasTarget())
     return llvm::createStringError(llvm::errc::not_supported,
                                    "Initialization failed. "

clang/tools/clang-import-test/clang-import-test.cpp

@@ -208,7 +208,7 @@ std::unique_ptr<CompilerInstance> BuildCompilerInstance() {
   Ins->setInvocation(std::move(Inv));
 
   TargetInfo *TI = TargetInfo::CreateTargetInfo(
-      Ins->getDiagnostics(), Ins->getInvocation().TargetOpts);
+      Ins->getDiagnostics(), Ins->getInvocation().getTargetOpts());
   Ins->setTarget(TI);
   Ins->getTarget().adjust(Ins->getDiagnostics(), Ins->getLangOpts());
   Ins->createFileManager();

clang/unittests/Analysis/MacroExpansionContextTest.cpp

@@ -39,7 +39,7 @@ protected:
         Diags(DiagID, DiagOpts.get(), new IgnoringDiagConsumer()),
         SourceMgr(Diags, FileMgr), TargetOpts(new TargetOptions()) {
     TargetOpts->Triple = "x86_64-pc-linux-unknown";
-    Target = TargetInfo::CreateTargetInfo(Diags, TargetOpts);
+    Target = TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
     LangOpts.CPlusPlus20 = 1; // For __VA_OPT__
   }
 

clang/unittests/Basic/SourceManagerTest.cpp

@@ -46,7 +46,7 @@ protected:
       SourceMgr(Diags, FileMgr),
       TargetOpts(new TargetOptions) {
     TargetOpts->Triple = "x86_64-apple-darwin11.1.0";
-    Target = TargetInfo::CreateTargetInfo(Diags, TargetOpts);
+    Target = TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
   }
 
   FileSystemOptions FileMgrOpts;

clang/unittests/CodeGen/TestCompiler.h

@@ -45,8 +45,7 @@ struct TestCompiler {
     Tr.setEnvironment(Triple::EnvironmentType::UnknownEnvironment);
     compiler.getTargetOpts().Triple = Tr.getTriple();
     compiler.setTarget(clang::TargetInfo::CreateTargetInfo(
-        compiler.getDiagnostics(),
-        std::make_shared<clang::TargetOptions>(compiler.getTargetOpts())));
+        compiler.getDiagnostics(), compiler.getTargetOpts()));
 
     const clang::TargetInfo &TInfo = compiler.getTarget();
     PtrSize = TInfo.getPointerWidth(clang::LangAS::Default) / 8;

clang/unittests/Driver/ToolChainTest.cpp

@@ -589,8 +589,7 @@ TEST(ToolChainTest, UEFICallingConventionTest) {
 
   compiler.getTargetOpts().Triple = Tr.getTriple();
   compiler.setTarget(clang::TargetInfo::CreateTargetInfo(
-      compiler.getDiagnostics(),
-      std::make_shared<clang::TargetOptions>(compiler.getTargetOpts())));
+      compiler.getDiagnostics(), compiler.getTargetOpts()));
 
   EXPECT_EQ(compiler.getTarget().getCallingConvKind(true),
             TargetInfo::CallingConvKind::CCK_MicrosoftWin64);

clang/unittests/Frontend/UtilsTest.cpp

@@ -33,7 +33,7 @@ TEST(BuildCompilerInvocationTest, RecoverMultipleJobs) {
       *Opts.VFS, new DiagnosticOptions, &D, false);
   std::unique_ptr<CompilerInvocation> CI = createInvocation(Args, Opts);
   ASSERT_TRUE(CI);
-  EXPECT_THAT(CI->TargetOpts->Triple, testing::StartsWith("i386-"));
+  EXPECT_THAT(CI->getTargetOpts().Triple, testing::StartsWith("i386-"));
 }
 
 // buildInvocationFromCommandLine should not translate -include to -include-pch,

clang/unittests/Lex/HeaderSearchTest.cpp

@@ -34,7 +34,7 @@ protected:
         SourceMgr(Diags, FileMgr), TargetOpts(new TargetOptions),
         Search(HSOpts, SourceMgr, Diags, LangOpts, Target.get()) {
     TargetOpts->Triple = "x86_64-apple-darwin11.1.0";
-    Target = TargetInfo::CreateTargetInfo(Diags, TargetOpts);
+    Target = TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
   }
 
   void addSearchDir(llvm::StringRef Dir) {

clang/unittests/Lex/LexerTest.cpp

@@ -48,7 +48,7 @@ protected:
       TargetOpts(new TargetOptions)
   {
     TargetOpts->Triple = "x86_64-apple-darwin11.1.0";
-    Target = TargetInfo::CreateTargetInfo(Diags, TargetOpts);
+    Target = TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
   }
 
   std::unique_ptr<Preprocessor> CreatePP(StringRef Source,

clang/unittests/Lex/ModuleDeclStateTest.cpp

@@ -58,7 +58,7 @@ protected:
         Diags(DiagID, new DiagnosticOptions, new IgnoringDiagConsumer()),
         SourceMgr(Diags, FileMgr), TargetOpts(new TargetOptions) {
     TargetOpts->Triple = "x86_64-unknown-linux-gnu";
-    Target = TargetInfo::CreateTargetInfo(Diags, TargetOpts);
+    Target = TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
   }
 
   std::unique_ptr<Preprocessor>

clang/unittests/Lex/PPCallbacksTest.cpp

@@ -139,7 +139,7 @@ protected:
         Diags(DiagID, DiagOpts.get(), new IgnoringDiagConsumer()),
         SourceMgr(Diags, FileMgr), TargetOpts(new TargetOptions()) {
     TargetOpts->Triple = "x86_64-apple-darwin11.1.0";
-    Target = TargetInfo::CreateTargetInfo(Diags, TargetOpts);
+    Target = TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
   }
 
   IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem;

clang/unittests/Lex/PPConditionalDirectiveRecordTest.cpp

@@ -36,7 +36,7 @@ protected:
       TargetOpts(new TargetOptions)
   {
     TargetOpts->Triple = "x86_64-apple-darwin11.1.0";
-    Target = TargetInfo::CreateTargetInfo(Diags, TargetOpts);
+    Target = TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
   }
 
   FileSystemOptions FileMgrOpts;

clang/unittests/Lex/PPDependencyDirectivesTest.cpp

@@ -35,7 +35,7 @@ protected:
         Diags(DiagID, new DiagnosticOptions, new IgnoringDiagConsumer()),
         SourceMgr(Diags, FileMgr), TargetOpts(new TargetOptions) {
     TargetOpts->Triple = "x86_64-apple-macos12";
-    Target = TargetInfo::CreateTargetInfo(Diags, TargetOpts);
+    Target = TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
   }
 
   FileSystemOptions FileMgrOpts;

clang/unittests/Lex/PPMemoryAllocationsTest.cpp

@@ -31,7 +31,7 @@ protected:
         Diags(DiagID, new DiagnosticOptions, new IgnoringDiagConsumer()),
         SourceMgr(Diags, FileMgr), TargetOpts(new TargetOptions) {
     TargetOpts->Triple = "x86_64-apple-darwin11.1.0";
-    Target = TargetInfo::CreateTargetInfo(Diags, TargetOpts);
+    Target = TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
   }
 
   FileSystemOptions FileMgrOpts;

clang/unittests/Parse/ParseHLSLRootSignatureTest.cpp

@@ -72,7 +72,7 @@ protected:
         SourceMgr(Diags, FileMgr), TargetOpts(new TargetOptions) {
     // This is an arbitrarily chosen target triple to create the target info.
     TargetOpts->Triple = "dxil";
-    Target = TargetInfo::CreateTargetInfo(Diags, TargetOpts);
+    Target = TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
   }
 
   std::unique_ptr<Preprocessor> createPP(StringRef Source,

lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp

@@ -789,7 +789,7 @@ ClangExpressionParser::ClangExpressionParser(
 
   if (auto *target_info = TargetInfo::CreateTargetInfo(
           m_compiler->getDiagnostics(),
-          m_compiler->getInvocation().TargetOpts)) {
+          m_compiler->getInvocation().getTargetOpts())) {
     if (log) {
       LLDB_LOGF(log, "Target datalayout string: '%s'",
                 target_info->getDataLayoutString());

lldb/source/Plugins/ExpressionParser/Clang/ClangModulesDeclVendor.cpp

@@ -742,7 +742,7 @@ ClangModulesDeclVendor::Create(Target &target) {
   std::unique_ptr<clang::FrontendAction> action(new clang::SyntaxOnlyAction);
 
   instance->setTarget(clang::TargetInfo::CreateTargetInfo(
-      *diagnostics_engine, instance->getInvocation().TargetOpts));
+      *diagnostics_engine, instance->getInvocation().getTargetOpts()));
 
   if (!instance->hasTarget())
     return nullptr;

lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp

@@ -744,7 +744,7 @@ TargetInfo *TypeSystemClang::getTargetInfo() {
   // target_triple should be something like "x86_64-apple-macosx"
   if (m_target_info_up == nullptr && !m_target_triple.empty())
     m_target_info_up.reset(TargetInfo::CreateTargetInfo(
-        getASTContext().getDiagnostics(), getTargetOptions()));
+        getASTContext().getDiagnostics(), *getTargetOptions()));
   return m_target_info_up.get();
 }