Driver, IRGen: Set partitions on GlobalValues according to -fsymbol-partition flag.

[pcc]

Ping.

[rsmith]

LGTM

clang/include/clang/Driver/Options.td

938

Please wrap to 80 columns.

clang/include/clang/Basic/CodeGenOptions.h

public:
   /// The name of the file to which the backend should save YAML optimization
   /// records.
   std::string OptRecordFile;
 
   /// The regex that filters the passes that should be saved to the optimization
   /// records.
   std::string OptRecordPasses;
 
+  /// The name of the partition that symbols are assigned to, specified with
+  /// -fsymbol-partition (see https://lld.llvm.org/Partitions.html).
+  std::string SymbolPartition;
+
   /// Regular expression to select optimizations for which we should enable
   /// optimization remarks. Transformation passes whose name matches this
   /// expression (and support this feature), will emit a diagnostic
   /// whenever they perform a transformation. This is enabled by the
   /// -Rpass=regexp flag.
   std::shared_ptr<llvm::Regex> OptimizationRemarkPattern;
 
   /// Regular expression to select optimizations for which we should enable

clang/include/clang/Driver/Options.td

def fno_fixed_point : Flag<["-"], "fno-fixed-point">, Group<f_Group>,
                       HelpText<"Disable fixed point types">;
 def fcxx_static_destructors : Flag<["-"], "fc++-static-destructors">,
   Group<f_Group>,
   HelpText<"Enable C++ static destructor registration (the default)">;
 def fno_cxx_static_destructors : Flag<["-"], "fno-c++-static-destructors">,
   Group<f_Group>,
   Flags<[CC1Option]>,
   HelpText<"Disable C++ static destructor registration">;
+def fsymbol_partition_EQ : Joined<["-"], "fsymbol-partition=">, Group<f_Group>, Flags<[CC1Option]>;
 
 // Begin sanitizer flags. These should all be core options exposed in all driver
 // modes.
 let Flags = [CC1Option, CoreOption] in {
 
 def fsanitize_EQ : CommaJoined<["-"], "fsanitize=">, Group<f_clang_Group>,
                    MetaVarName<"<check>">,
                    HelpText<"Turn on runtime checks for various forms of undefined "

clang/lib/CodeGen/CodeGenModule.h

void DecorateInstructionWithInvariantGroup(llvm::Instruction *I,
                                              const CXXRecordDecl *RD);
 
   /// Emit the given number of characters as a value of type size_t.
   llvm::ConstantInt *getSize(CharUnits numChars);
 
   /// Set the visibility for the given LLVM GlobalValue.
   void setGlobalVisibility(llvm::GlobalValue *GV, const NamedDecl *D) const;
 
-  void setGlobalVisibilityAndLocal(llvm::GlobalValue *GV,
-                                   const NamedDecl *D) const;
-
   void setDSOLocal(llvm::GlobalValue *GV) const;
 
   void setDLLImportDLLExport(llvm::GlobalValue *GV, GlobalDecl D) const;
   void setDLLImportDLLExport(llvm::GlobalValue *GV, const NamedDecl *D) const;
   /// Set visibility, dllimport/dllexport and dso_local.
   /// This must be called after dllimport/dllexport is set.
   void setGVProperties(llvm::GlobalValue *GV, GlobalDecl GD) const;
   void setGVProperties(llvm::GlobalValue *GV, const NamedDecl *D) const;
 
+  void setGVPropertiesAux(llvm::GlobalValue *GV, const NamedDecl *D) const;
+
   /// Set the TLS mode for the given LLVM GlobalValue for the thread-local
   /// variable declaration D.
   void setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const;
 
   static llvm::GlobalValue::VisibilityTypes GetLLVMVisibility(Visibility V) {
     switch (V) {
     case DefaultVisibility:   return llvm::GlobalValue::DefaultVisibility;
     case HiddenVisibility:    return llvm::GlobalValue::HiddenVisibility;

clang/lib/CodeGen/CodeGenModule.cpp

if (D && D->isExternallyVisible()) {
     else if (D->hasAttr<DLLExportAttr>() && !GV->isDeclarationForLinker())
       GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
   }
 }
 
 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
                                     GlobalDecl GD) const {
   setDLLImportDLLExport(GV, GD);
-  setGlobalVisibilityAndLocal(GV, dyn_cast<NamedDecl>(GD.getDecl()));
+  setGVPropertiesAux(GV, dyn_cast<NamedDecl>(GD.getDecl()));
 }
 
 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
                                     const NamedDecl *D) const {
   setDLLImportDLLExport(GV, D);
-  setGlobalVisibilityAndLocal(GV, D);
+  setGVPropertiesAux(GV, D);
 }
 
-void CodeGenModule::setGlobalVisibilityAndLocal(llvm::GlobalValue *GV,
-                                                const NamedDecl *D) const {
+void CodeGenModule::setGVPropertiesAux(llvm::GlobalValue *GV,
   setGlobalVisibility(GV, D);
   setDSOLocal(GV);
+  GV->setPartition(CodeGenOpts.SymbolPartition);
 }
 
 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
   return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
       .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
       .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
       .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
       .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);

clang/lib/CodeGen/ItaniumCXXABI.cpp

#include "clang/AST/TypeNodes.def"
   CGM.setDSOLocal(TypeName);
 
   GV->setVisibility(Visibility);
   CGM.setDSOLocal(GV);
 
   TypeName->setDLLStorageClass(DLLStorageClass);
   GV->setDLLStorageClass(DLLStorageClass);
 
+  TypeName->setPartition(CGM.getCodeGenOpts().SymbolPartition);
+  GV->setPartition(CGM.getCodeGenOpts().SymbolPartition);
+
   return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
 }
 
 /// BuildObjCObjectTypeInfo - Build the appropriate kind of type_info
 /// for the given Objective-C object type.
 void ItaniumRTTIBuilder::BuildObjCObjectTypeInfo(const ObjCObjectType *OT) {
   // Drop qualifiers.
   const Type *T = OT->getBaseType().getTypePtr();

clang/lib/Driver/ToolChains/Clang.cpp

if (Args.hasFlag(options::OPT_faddrsig, options::OPT_fno_addrsig,
                     TC.getTriple().isOSBinFormatCOFF()) &&
                       !TC.getTriple().isPS4() &&
                       !TC.getTriple().isOSNetBSD() &&
                       !Distro(D.getVFS()).IsGentoo() &&
                       !TC.getTriple().isAndroid() &&
                        TC.useIntegratedAs()))
     CmdArgs.push_back("-faddrsig");
 
+  if (Arg *A = Args.getLastArg(options::OPT_fsymbol_partition_EQ)) {
+    std::string Str = A->getAsString(Args);
+    if (!TC.getTriple().isOSBinFormatELF())
+      D.Diag(diag::err_drv_unsupported_opt_for_target)
+          << Str << TC.getTripleString();
+    CmdArgs.push_back(Args.MakeArgString(Str));
+  }
+
   // Add the "-o out -x type src.c" flags last. This is done primarily to make
   // the -cc1 command easier to edit when reproducing compiler crashes.
   if (Output.getType() == types::TY_Dependencies) {
     // Handled with other dependency code.
   } else if (Output.isFilename()) {
     CmdArgs.push_back("-o");
     CmdArgs.push_back(Output.getFilename());
   } else {

clang/lib/Frontend/CompilerInvocation.cpp

static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.KeepStaticConsts = Args.hasArg(OPT_fkeep_static_consts);
 
   Opts.SpeculativeLoadHardening = Args.hasArg(OPT_mspeculative_load_hardening);
 
   Opts.DefaultFunctionAttrs = Args.getAllArgValues(OPT_default_function_attr);
 
   Opts.PassPlugins = Args.getAllArgValues(OPT_fpass_plugin_EQ);
 
+  Opts.SymbolPartition = Args.getLastArgValue(OPT_fsymbol_partition_EQ);
+
   return Success;
 }
 
 static void ParseDependencyOutputArgs(DependencyOutputOptions &Opts,
                                       ArgList &Args) {
   Opts.OutputFile = Args.getLastArgValue(OPT_dependency_file);
   Opts.Targets = Args.getAllArgValues(OPT_MT);
   Opts.IncludeSystemHeaders = Args.hasArg(OPT_sys_header_deps);

clang/test/CodeGenCXX/symbol-partition.cpp

+// RUN: %clang_cc1 -fsymbol-partition=foo -emit-llvm -o - | FileCheck %s
+
+// CHECK: @gv = {{.*}}, partition "foo"
+// CHECK: @_ZTV1S = {{.*}}, partition "foo"
+// CHECK: @_ZTS1S = {{.*}}, partition "foo"
+// CHECK: @_ZTI1S = {{.*}}, partition "foo"
+
+// CHECK: @_Z5ifuncv = {{.*}}, partition "foo"
+
+// CHECK: define {{.*}} @_ZN1S1fEv({{.*}} partition "foo"
+// CHECK: define {{.*}} @f({{.*}} partition "foo"
+
+struct S {
+  virtual void f();
+};
+
+void S::f() {}
+
+int gv;
+extern "C" void *f() { return 0; }
+void ifunc() __attribute__((ifunc("f")));

clang/test/Driver/symbol-partition.c

+// RUN: %clang -### -target x86_64-unknown-linux -c -fsymbol-partition=foo %s 2>&1 | FileCheck %s
+// RUN: %clang -### -target x86_64-pc-win32 -c -fsymbol-partition=foo %s 2>&1 | FileCheck --check-prefix=ERROR %s
+
+// CHECK: "-fsymbol-partition=foo"
+// ERROR: clang: error: unsupported option '-fsymbol-partition=foo' for target 'x86_64-pc-windows-msvc'