Revert "[flang] add option to generate runtime type info as external (llvm#146071)"

ronlieb · ronlieb · commit 999b216135b5 · 2025-06-30T14:03:09.000-05:00
breaks Compile Fails -------------------- flang-364228-0: Make Failed flang-364228-1: Make Failed target-cray-pointer: Make Failed This reverts commit faefe7c.
diff --git a/flang/include/flang/Evaluate/tools.h b/flang/include/flang/Evaluate/tools.h
@@ -1585,7 +1585,6 @@ bool IsExtensibleType(const DerivedTypeSpec *);
 bool IsSequenceOrBindCType(const DerivedTypeSpec *);
 bool IsBuiltinDerivedType(const DerivedTypeSpec *derived, const char *name);
 bool IsBuiltinCPtr(const Symbol &);
-bool IsFromBuiltinModule(const Symbol &);
 bool IsEventType(const DerivedTypeSpec *);
 bool IsLockType(const DerivedTypeSpec *);
 bool IsNotifyType(const DerivedTypeSpec *);
diff --git a/flang/include/flang/Lower/LoweringOptions.def b/flang/include/flang/Lower/LoweringOptions.def
@@ -66,9 +66,5 @@ ENUM_LOWERINGOPT(RepackArraysWhole, unsigned, 1, 0)
 /// If true, CUDA Fortran runtime check is inserted.
 ENUM_LOWERINGOPT(CUDARuntimeCheck, unsigned, 1, 0)
 
-/// If true, do not generate definition for runtime type info global objects of
-/// derived types defined in other compilation units.
-ENUM_LOWERINGOPT(SkipExternalRttiDefinition, unsigned, 1, 0)
-
 #undef LOWERINGOPT
 #undef ENUM_LOWERINGOPT
diff --git a/flang/include/flang/Optimizer/CodeGen/CodeGen.h b/flang/include/flang/Optimizer/CodeGen/CodeGen.h
@@ -39,9 +39,6 @@ struct FIRToLLVMPassOptions {
   // that such programs would crash at runtime if the derived type descriptors
   // are required by the runtime, so this is only an option to help debugging.
   bool ignoreMissingTypeDescriptors = false;
-  // Similar to ignoreMissingTypeDescriptors, but generate external declaration
-  // for the missing type descriptor globals instead.
-  bool skipExternalRttiDefinition = false;
 
   // Generate TBAA information for FIR types and memory accessing operations.
   bool applyTBAA = false;
diff --git a/flang/include/flang/Optimizer/Passes/CommandLineOpts.h b/flang/include/flang/Optimizer/Passes/CommandLineOpts.h
@@ -32,19 +32,6 @@ extern llvm::cl::opt<std::size_t> arrayStackAllocationThreshold;
 /// generated by the frontend.
 extern llvm::cl::opt<bool> ignoreMissingTypeDescriptors;
 
-/// Shared option in tools to only generate rtti static object definitions for
-/// derived types defined in the current compilation unit. Derived type
-/// descriptor object for types defined in other objects will only be declared
-/// as external. This also changes the linkage of rtti objects defined in the
-/// current compilation unit from linkonce_odr to external so that unused rtti
-/// objects are retained and can be accessed from other compilation units. This
-/// is an experimental option to explore compilation speed improvements and is
-/// an ABI breaking change because of the linkage change.
-/// It will also require linking against module file objects of modules defining
-/// only types (even for trivial types without type bound procedures, which
-/// differs from most compilers).
-extern llvm::cl::opt<bool> skipExternalRttiDefinition;
-
 /// Default optimization level used to create Flang pass pipeline is O0.
 extern llvm::OptimizationLevel defaultOptLevel;
 
diff --git a/flang/include/flang/Optimizer/Support/Utils.h b/flang/include/flang/Optimizer/Support/Utils.h
@@ -35,6 +35,32 @@ inline std::int64_t toInt(mlir::arith::ConstantOp cop) {
       .getSExtValue();
 }
 
+// Reconstruct binding tables for dynamic dispatch.
+using BindingTable = llvm::DenseMap<llvm::StringRef, unsigned>;
+using BindingTables = llvm::DenseMap<llvm::StringRef, BindingTable>;
+
+inline void buildBindingTables(BindingTables &bindingTables,
+                               mlir::ModuleOp mod) {
+
+  // The binding tables are defined in FIR after lowering inside fir.type_info
+  // operations. Go through each binding tables and store the procedure name and
+  // binding index for later use by the fir.dispatch conversion pattern.
+  for (auto typeInfo : mod.getOps<fir::TypeInfoOp>()) {
+    unsigned bindingIdx = 0;
+    BindingTable bindings;
+    if (typeInfo.getDispatchTable().empty()) {
+      bindingTables[typeInfo.getSymName()] = bindings;
+      continue;
+    }
+    for (auto dtEntry :
+         typeInfo.getDispatchTable().front().getOps<fir::DTEntryOp>()) {
+      bindings[dtEntry.getMethod()] = bindingIdx;
+      ++bindingIdx;
+    }
+    bindingTables[typeInfo.getSymName()] = bindings;
+  }
+}
+
 // Translate front-end KINDs for use in the IR and code gen.
 inline std::vector<fir::KindTy>
 fromDefaultKinds(const Fortran::common::IntrinsicTypeDefaultKinds &defKinds) {
diff --git a/flang/include/flang/Semantics/runtime-type-info.h b/flang/include/flang/Semantics/runtime-type-info.h
@@ -38,10 +38,6 @@ RuntimeDerivedTypeTables BuildRuntimeDerivedTypeTables(SemanticsContext &);
 /// to describe other derived types at runtime in flang descriptor.
 constexpr char typeInfoBuiltinModule[]{"__fortran_type_info"};
 
-/// Name of the builtin derived type in __fortran_type_inf that is used for
-/// derived type descriptors.
-constexpr char typeDescriptorTypeName[]{"derivedtype"};
-
 /// Name of the bindings descriptor component in the DerivedType type of the
 /// __Fortran_type_info module
 constexpr char bindingDescCompName[]{"binding"};
diff --git a/flang/lib/Evaluate/tools.cpp b/flang/lib/Evaluate/tools.cpp
@@ -2334,11 +2334,6 @@ bool IsBuiltinCPtr(const Symbol &symbol) {
   return false;
 }
 
-bool IsFromBuiltinModule(const Symbol &symbol) {
-  const Scope &scope{symbol.GetUltimate().owner()};
-  return IsSameModule(&scope, scope.context().GetBuiltinsScope());
-}
-
 bool IsIsoCType(const DerivedTypeSpec *derived) {
   return IsBuiltinDerivedType(derived, "c_ptr") ||
       IsBuiltinDerivedType(derived, "c_funptr");
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -14,7 +14,6 @@
 #include "flang/Frontend/CodeGenOptions.h"
 #include "flang/Frontend/PreprocessorOptions.h"
 #include "flang/Frontend/TargetOptions.h"
-#include "flang/Optimizer/Passes/CommandLineOpts.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Support/Fortran-features.h"
 #include "flang/Support/OpenMP-features.h"
@@ -1808,7 +1807,6 @@ void CompilerInvocation::setLoweringOptions() {
   // Lower TRANSPOSE as a runtime call under -O0.
   loweringOpts.setOptimizeTranspose(codegenOpts.OptimizationLevel > 0);
   loweringOpts.setUnderscoring(codegenOpts.Underscoring);
-  loweringOpts.setSkipExternalRttiDefinition(skipExternalRttiDefinition);
 
   const Fortran::common::LangOptions &langOptions = getLangOpts();
   loweringOpts.setIntegerWrapAround(langOptions.getSignedOverflowBehavior() ==
diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
@@ -263,7 +263,6 @@ class TypeInfoConverter {
   }
 
   void createTypeInfo(Fortran::lower::AbstractConverter &converter) {
-    createTypeInfoForTypeDescriptorBuiltinType(converter);
     while (!registeredTypeInfoA.empty()) {
       currentTypeInfoStack = &registeredTypeInfoB;
       for (const TypeInfo &info : registeredTypeInfoA)
@@ -279,22 +278,10 @@ class TypeInfoConverter {
 private:
   void createTypeInfoOpAndGlobal(Fortran::lower::AbstractConverter &converter,
                                  const TypeInfo &info) {
-    if (!converter.getLoweringOptions().getSkipExternalRttiDefinition())
-      Fortran::lower::createRuntimeTypeInfoGlobal(converter, info.symbol.get());
+    Fortran::lower::createRuntimeTypeInfoGlobal(converter, info.symbol.get());
     createTypeInfoOp(converter, info);
   }
 
-  void createTypeInfoForTypeDescriptorBuiltinType(
-      Fortran::lower::AbstractConverter &converter) {
-    if (registeredTypeInfoA.empty())
-      return;
-    auto builtinTypeInfoType = llvm::cast<fir::RecordType>(
-        converter.genType(registeredTypeInfoA[0].symbol.get()));
-    converter.getFirOpBuilder().createTypeInfoOp(
-        registeredTypeInfoA[0].loc, builtinTypeInfoType,
-        /*parentType=*/fir::RecordType{});
-  }
-
   void createTypeInfoOp(Fortran::lower::AbstractConverter &converter,
                         const TypeInfo &info) {
     fir::RecordType parentType{};
diff --git a/flang/lib/Lower/ConvertVariable.cpp b/flang/lib/Lower/ConvertVariable.cpp
@@ -647,19 +647,13 @@ fir::GlobalOp Fortran::lower::defineGlobal(
 
 /// Return linkage attribute for \p var.
 static mlir::StringAttr
-getLinkageAttribute(Fortran::lower::AbstractConverter &converter,
+getLinkageAttribute(fir::FirOpBuilder &builder,
                     const Fortran::lower::pft::Variable &var) {
-  fir::FirOpBuilder &builder = converter.getFirOpBuilder();
   // Runtime type info for a same derived type is identical in each compilation
   // unit. It desired to avoid having to link against module that only define a
   // type. Therefore the runtime type info is generated everywhere it is needed
-  // with `linkonce_odr` LLVM linkage (unless the skipExternalRttiDefinition
-  // option is set, in which case one will need to link against objects of
-  // modules defining types). Builtin objects rtti is always generated because
-  // the builtin module is currently not compiled or part of the runtime.
-  if (var.isRuntimeTypeInfoData() &&
-      (!converter.getLoweringOptions().getSkipExternalRttiDefinition() ||
-       Fortran::semantics::IsFromBuiltinModule(var.getSymbol())))
+  // with `linkonce_odr` LLVM linkage.
+  if (var.isRuntimeTypeInfoData())
     return builder.createLinkOnceODRLinkage();
   if (var.isModuleOrSubmoduleVariable())
     return {}; // external linkage
@@ -679,7 +673,7 @@ static void instantiateGlobal(Fortran::lower::AbstractConverter &converter,
   fir::FirOpBuilder &builder = converter.getFirOpBuilder();
   std::string globalName = converter.mangleName(sym);
   mlir::Location loc = genLocation(converter, sym);
-  mlir::StringAttr linkage = getLinkageAttribute(converter, var);
+  mlir::StringAttr linkage = getLinkageAttribute(builder, var);
   fir::GlobalOp global;
   if (var.isModuleOrSubmoduleVariable()) {
     // A non-intrinsic module global is defined when lowering the module.
@@ -1271,7 +1265,7 @@ instantiateAggregateStore(Fortran::lower::AbstractConverter &converter,
   if (var.isGlobal()) {
     fir::GlobalOp global;
     auto &aggregate = var.getAggregateStore();
-    mlir::StringAttr linkage = getLinkageAttribute(converter, var);
+    mlir::StringAttr linkage = getLinkageAttribute(builder, var);
     if (var.isModuleOrSubmoduleVariable()) {
       // A module global was or will be defined when lowering the module. Emit
       // only a declaration if the global does not exist at that point.
@@ -2476,7 +2470,8 @@ void Fortran::lower::defineModuleVariable(
     AbstractConverter &converter, const Fortran::lower::pft::Variable &var) {
   // Use empty linkage for module variables, which makes them available
   // for use in another unit.
-  mlir::StringAttr linkage = getLinkageAttribute(converter, var);
+  mlir::StringAttr linkage =
+      getLinkageAttribute(converter.getFirOpBuilder(), var);
   if (!var.isGlobal())
     fir::emitFatalError(converter.getCurrentLocation(),
                         "attempting to lower module variable as local");
@@ -2611,9 +2606,10 @@ void Fortran::lower::createIntrinsicModuleGlobal(
 void Fortran::lower::createRuntimeTypeInfoGlobal(
     Fortran::lower::AbstractConverter &converter,
     const Fortran::semantics::Symbol &typeInfoSym) {
+  fir::FirOpBuilder &builder = converter.getFirOpBuilder();
   std::string globalName = converter.mangleName(typeInfoSym);
   auto var = Fortran::lower::pft::Variable(typeInfoSym, /*global=*/true);
-  mlir::StringAttr linkage = getLinkageAttribute(converter, var);
+  mlir::StringAttr linkage = getLinkageAttribute(builder, var);
   defineGlobal(converter, var, globalName, linkage);
 }
 
diff --git a/flang/lib/Optimizer/CodeGen/CodeGen.cpp b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
@@ -1332,51 +1332,6 @@ genCUFAllocDescriptor(mlir::Location loc,
       .getResult();
 }
 
-/// Get the address of the type descriptor global variable that was created by
-/// lowering for derived type \p recType.
-template <typename ModOpTy>
-static mlir::Value
-getTypeDescriptor(ModOpTy mod, mlir::ConversionPatternRewriter &rewriter,
-                  mlir::Location loc, fir::RecordType recType,
-                  const fir::FIRToLLVMPassOptions &options) {
-  std::string name =
-      options.typeDescriptorsRenamedForAssembly
-          ? fir::NameUniquer::getTypeDescriptorAssemblyName(recType.getName())
-          : fir::NameUniquer::getTypeDescriptorName(recType.getName());
-  mlir::Type llvmPtrTy = ::getLlvmPtrType(mod.getContext());
-  if (auto global = mod.template lookupSymbol<fir::GlobalOp>(name))
-    return rewriter.create<mlir::LLVM::AddressOfOp>(loc, llvmPtrTy,
-                                                    global.getSymName());
-  // The global may have already been translated to LLVM.
-  if (auto global = mod.template lookupSymbol<mlir::LLVM::GlobalOp>(name))
-    return rewriter.create<mlir::LLVM::AddressOfOp>(loc, llvmPtrTy,
-                                                    global.getSymName());
-  // Type info derived types do not have type descriptors since they are the
-  // types defining type descriptors.
-  if (options.ignoreMissingTypeDescriptors ||
-      fir::NameUniquer::belongsToModule(
-          name, Fortran::semantics::typeInfoBuiltinModule))
-    return rewriter.create<mlir::LLVM::ZeroOp>(loc, llvmPtrTy);
-
-  if (!options.skipExternalRttiDefinition)
-    fir::emitFatalError(loc,
-                        "runtime derived type info descriptor was not "
-                        "generated and skipExternalRttiDefinition and "
-                        "ignoreMissingTypeDescriptors options are not set");
-
-  // Rtti for a derived type defined in another compilation unit and for which
-  // rtti was not defined in lowering because of the skipExternalRttiDefinition
-  // option. Generate the object declaration now.
-  auto insertPt = rewriter.saveInsertionPoint();
-  rewriter.setInsertionPoint(mod.getBody(), mod.getBody()->end());
-  mlir::LLVM::GlobalOp global = rewriter.create<mlir::LLVM::GlobalOp>(
-      loc, llvmPtrTy, /*constant=*/true, mlir::LLVM::Linkage::External, name,
-      mlir::Attribute());
-  rewriter.restoreInsertionPoint(insertPt);
-  return rewriter.create<mlir::LLVM::AddressOfOp>(loc, llvmPtrTy,
-                                                  global.getSymName());
-}
-
 /// Common base class for embox to descriptor conversion.
 template <typename OP>
 struct EmboxCommonConversion : public fir::FIROpConversion<OP> {
@@ -1489,7 +1444,6 @@ struct EmboxCommonConversion : public fir::FIROpConversion<OP> {
                        stride);
   }
 
-#if 0//<<<<<<< HEAD
   /// Get the address of the type descriptor global variable that was created by
   /// lowering for derived type \p recType.
   template <typename ModOpTy>
@@ -1525,7 +1479,6 @@ struct EmboxCommonConversion : public fir::FIROpConversion<OP> {
     return rewriter.create<mlir::LLVM::ZeroOp>(loc, llvmPtrTy);
   }
 
-#endif//>>>>>>> d4fdfc3aa718b7cdc96a6e4bab4462247bc7940b
   template <typename ModOpTy>
   mlir::Value populateDescriptor(mlir::Location loc, ModOpTy mod,
                                  fir::BaseBoxType boxTy, mlir::Type inputType,
@@ -1590,17 +1543,16 @@ struct EmboxCommonConversion : public fir::FIROpConversion<OP> {
           mlir::Type innerType = fir::unwrapInnerType(inputType);
           if (innerType && mlir::isa<fir::RecordType>(innerType)) {
             auto recTy = mlir::dyn_cast<fir::RecordType>(innerType);
-            typeDesc =
-                getTypeDescriptor(mod, rewriter, loc, recTy, this->options);
+            typeDesc = getTypeDescriptor(mod, rewriter, loc, recTy);
           } else {
             // Unlimited polymorphic type descriptor with no record type. Set
             // type descriptor address to a clean state.
             typeDesc = rewriter.create<mlir::LLVM::ZeroOp>(
                 loc, ::getLlvmPtrType(mod.getContext()));
           }
         } else {
-          typeDesc = getTypeDescriptor(
-              mod, rewriter, loc, fir::unwrapIfDerived(boxTy), this->options);
+          typeDesc = getTypeDescriptor(mod, rewriter, loc,
+                                       fir::unwrapIfDerived(boxTy));
         }
       }
       if (typeDesc)
@@ -3112,7 +3064,6 @@ struct TypeDescOpConversion : public fir::FIROpConversion<fir::TypeDescOp> {
     assert(mlir::isa<fir::RecordType>(inTy) && "expecting fir.type");
     auto recordType = mlir::dyn_cast<fir::RecordType>(inTy);
     auto module = typeDescOp.getOperation()->getParentOfType<mlir::ModuleOp>();
-#if 0//<<<<<<< HEAD
     std::string typeDescName =
         this->options.typeDescriptorsRenamedForAssembly
             ? fir::NameUniquer::getTypeDescriptorAssemblyName(
@@ -3133,12 +3084,6 @@ struct TypeDescOpConversion : public fir::FIROpConversion<fir::TypeDescOp> {
       return mlir::success();
     }
     return mlir::failure();
-#else//=======
-    mlir::Value typeDesc = getTypeDescriptor(
-        module, rewriter, typeDescOp.getLoc(), recordType, this->options);
-    rewriter.replaceOp(typeDescOp, typeDesc);
-    return mlir::success();
-#endif//>>>>>>> d4fdfc3aa718b7cdc96a6e4bab4462247bc7940b
   }
 };
 
diff --git a/flang/lib/Optimizer/Passes/CommandLineOpts.cpp b/flang/lib/Optimizer/Passes/CommandLineOpts.cpp
@@ -39,12 +39,6 @@ cl::opt<bool> ignoreMissingTypeDescriptors(
              "translating FIR to LLVM"),
     cl::init(false), cl::Hidden);
 
-cl::opt<bool> skipExternalRttiDefinition(
-    "skip-external-rtti-definition", llvm::cl::init(false),
-    llvm::cl::desc("do not define rtti static objects for types belonging to "
-                   "other compilation units"),
-    cl::Hidden);
-
 OptimizationLevel defaultOptLevel{OptimizationLevel::O0};
 
 codegenoptions::DebugInfoKind noDebugInfo{codegenoptions::NoDebugInfo};
diff --git a/flang/lib/Optimizer/Passes/Pipelines.cpp b/flang/lib/Optimizer/Passes/Pipelines.cpp
@@ -108,7 +108,6 @@ void addFIRToLLVMPass(mlir::PassManager &pm,
                       const MLIRToLLVMPassPipelineConfig &config) {
   fir::FIRToLLVMPassOptions options;
   options.ignoreMissingTypeDescriptors = ignoreMissingTypeDescriptors;
-  options.skipExternalRttiDefinition = skipExternalRttiDefinition;
   options.applyTBAA = config.AliasAnalysis;
   options.forceUnifiedTBAATree = useOldAliasTags;
   options.typeDescriptorsRenamedForAssembly =
diff --git a/flang/lib/Optimizer/Transforms/PolymorphicOpConversion.cpp b/flang/lib/Optimizer/Transforms/PolymorphicOpConversion.cpp
diff --git a/flang/test/Integration/skip-external-rtti-definition.F90 b/flang/test/Integration/skip-external-rtti-definition.F90
diff --git a/flang/test/Lower/select-type-2.f90 b/flang/test/Lower/select-type-2.f90
diff --git a/flang/test/Lower/select-type.f90 b/flang/test/Lower/select-type.f90
diff --git a/flang/tools/bbc/bbc.cpp b/flang/tools/bbc/bbc.cpp
