Recommit r224935 with a fix for the ObjC++/AArch64 bug that that revi…

…sion

introduced.

A test case for the bug was already committed in r225385.

Patch by Rafael Espindola.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225534 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/TargetLoweringObjectFileImpl.h

@@ -89,8 +89,6 @@ class TargetLoweringObjectFileMachO : public TargetLoweringObjectFile {
                        ArrayRef<Module::ModuleFlagEntry> ModuleFlags,
                        Mangler &Mang, const TargetMachine &TM) const override;
 
-  bool isSectionAtomizableBySymbols(const MCSection &Section) const override;
-
   const MCSection *
     SelectSectionForGlobal(const GlobalValue *GV,
                            SectionKind Kind, Mangler &Mang,

include/llvm/MC/MCAsmBackend.h

@@ -67,14 +67,6 @@ class MCAsmBackend {
     return false;
   }
 
-  /// isSectionAtomizable - Check whether the given section can be split into
-  /// atoms.
-  ///
-  /// \see MCAssembler::isSymbolLinkerVisible().
-  virtual bool isSectionAtomizable(const MCSection &Section) const {
-    return true;
-  }
-
   /// @name Target Fixup Interfaces
   /// @{
 

include/llvm/MC/MCAsmInfo.h

@@ -382,6 +382,12 @@ class MCAsmInfo {
     return nullptr;
   }
 
+  /// \brief True if the section is atomized using the symbols in it.
+  /// This is false if the section is not atomized at all (most ELF sections) or
+  /// if it is atomized based on its contents (MachO' __TEXT,__cstring for
+  /// example).
+  virtual bool isSectionAtomizableBySymbols(const MCSection &Section) const;
+
   virtual const MCExpr *getExprForPersonalitySymbol(const MCSymbol *Sym,
                                                     unsigned Encoding,
                                                     MCStreamer &Streamer) const;

include/llvm/MC/MCAsmInfoDarwin.h

@@ -19,9 +19,9 @@
 
 namespace llvm {
   class MCAsmInfoDarwin : public MCAsmInfo {
-    virtual void anchor();
   public:
     explicit MCAsmInfoDarwin();
+    bool isSectionAtomizableBySymbols(const MCSection &Section) const override;
   };
 }
 

include/llvm/Target/TargetLoweringObjectFile.h

@@ -151,12 +151,6 @@ class TargetLoweringObjectFile : public MCObjectFileInfo {
     return nullptr;
   }
 
-  /// \brief True if the section is atomized using the symbols in it.
-  /// This is false if the section is not atomized at all (most ELF sections) or
-  /// if it is atomized based on its contents (MachO' __TEXT,__cstring for
-  /// example).
-  virtual bool isSectionAtomizableBySymbols(const MCSection &Section) const;
-
 protected:
   virtual const MCSection *
   SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,

lib/CodeGen/TargetLoweringObjectFileImpl.cpp

@@ -573,60 +573,6 @@ const MCSection *TargetLoweringObjectFileMachO::getExplicitSectionGlobal(
   return S;
 }
 
-bool TargetLoweringObjectFileMachO::isSectionAtomizableBySymbols(
-    const MCSection &Section) const {
-    const MCSectionMachO &SMO = static_cast<const MCSectionMachO&>(Section);
-
-    // Sections holding 1 byte strings are atomized based on the data
-    // they contain.
-    // Sections holding 2 byte strings require symbols in order to be
-    // atomized.
-    // There is no dedicated section for 4 byte strings.
-    if (SMO.getKind().isMergeable1ByteCString())
-      return false;
-
-    if (SMO.getSegmentName() == "__TEXT" &&
-        SMO.getSectionName() == "__objc_classname" &&
-        SMO.getType() == MachO::S_CSTRING_LITERALS)
-      return false;
-
-    if (SMO.getSegmentName() == "__TEXT" &&
-        SMO.getSectionName() == "__objc_methname" &&
-        SMO.getType() == MachO::S_CSTRING_LITERALS)
-      return false;
-
-    if (SMO.getSegmentName() == "__TEXT" &&
-        SMO.getSectionName() == "__objc_methtype" &&
-        SMO.getType() == MachO::S_CSTRING_LITERALS)
-      return false;
-
-    if (SMO.getSegmentName() == "__DATA" &&
-        SMO.getSectionName() == "__cfstring")
-      return false;
-
-    // no_dead_strip sections are not atomized in practice.
-    if (SMO.hasAttribute(MachO::S_ATTR_NO_DEAD_STRIP))
-      return false;
-
-    switch (SMO.getType()) {
-    default:
-      return true;
-
-      // These sections are atomized at the element boundaries without using
-      // symbols.
-    case MachO::S_4BYTE_LITERALS:
-    case MachO::S_8BYTE_LITERALS:
-    case MachO::S_16BYTE_LITERALS:
-    case MachO::S_LITERAL_POINTERS:
-    case MachO::S_NON_LAZY_SYMBOL_POINTERS:
-    case MachO::S_LAZY_SYMBOL_POINTERS:
-    case MachO::S_MOD_INIT_FUNC_POINTERS:
-    case MachO::S_MOD_TERM_FUNC_POINTERS:
-    case MachO::S_INTERPOSING:
-      return false;
-    }
-}
-
 const MCSection *TargetLoweringObjectFileMachO::
 SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
                        Mangler &Mang, const TargetMachine &TM) const {

lib/MC/MCAsmInfo.cpp

@@ -109,6 +109,10 @@ MCAsmInfo::MCAsmInfo() {
 MCAsmInfo::~MCAsmInfo() {
 }
 
+bool MCAsmInfo::isSectionAtomizableBySymbols(const MCSection &Section) const {
+  return false;
+}
+
 const MCExpr *
 MCAsmInfo::getExprForPersonalitySymbol(const MCSymbol *Sym,
                                        unsigned Encoding,

lib/MC/MCAsmInfoDarwin.cpp

@@ -15,10 +15,57 @@
 #include "llvm/MC/MCAsmInfoDarwin.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCSectionMachO.h"
 #include "llvm/MC/MCStreamer.h"
 using namespace llvm;
 
-void MCAsmInfoDarwin::anchor() { }
+bool MCAsmInfoDarwin::isSectionAtomizableBySymbols(
+    const MCSection &Section) const {
+  const MCSectionMachO &SMO = static_cast<const MCSectionMachO &>(Section);
+
+  // Sections holding 1 byte strings are atomized based on the data they
+  // contain.
+  // Sections holding 2 byte strings require symbols in order to be atomized.
+  // There is no dedicated section for 4 byte strings.
+  if (SMO.getKind().isMergeable1ByteCString())
+    return false;
+
+  if (SMO.getSegmentName() == "__TEXT" &&
+      SMO.getSectionName() == "__objc_classname" &&
+      SMO.getType() == MachO::S_CSTRING_LITERALS)
+    return false;
+
+  if (SMO.getSegmentName() == "__TEXT" &&
+      SMO.getSectionName() == "__objc_methname" &&
+      SMO.getType() == MachO::S_CSTRING_LITERALS)
+    return false;
+
+  if (SMO.getSegmentName() == "__TEXT" &&
+      SMO.getSectionName() == "__objc_methtype" &&
+      SMO.getType() == MachO::S_CSTRING_LITERALS)
+    return false;
+
+  if (SMO.getSegmentName() == "__DATA" && SMO.getSectionName() == "__cfstring")
+    return false;
+
+  switch (SMO.getType()) {
+  default:
+    return true;
+
+  // These sections are atomized at the element boundaries without using
+  // symbols.
+  case MachO::S_4BYTE_LITERALS:
+  case MachO::S_8BYTE_LITERALS:
+  case MachO::S_16BYTE_LITERALS:
+  case MachO::S_LITERAL_POINTERS:
+  case MachO::S_NON_LAZY_SYMBOL_POINTERS:
+  case MachO::S_LAZY_SYMBOL_POINTERS:
+  case MachO::S_MOD_INIT_FUNC_POINTERS:
+  case MachO::S_MOD_TERM_FUNC_POINTERS:
+  case MachO::S_INTERPOSING:
+    return false;
+  }
+}
 
 MCAsmInfoDarwin::MCAsmInfoDarwin() {
   // Common settings for all Darwin targets.

lib/MC/MCAssembler.cpp

@@ -12,6 +12,7 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCAsmLayout.h"
 #include "llvm/MC/MCCodeEmitter.h"
 #include "llvm/MC/MCContext.h"
@@ -448,8 +449,8 @@ const MCSymbolData *MCAssembler::getAtom(const MCSymbolData *SD) const {
 
   // Non-linker visible symbols in sections which can't be atomized have no
   // defining atom.
-  if (!getBackend().isSectionAtomizable(
-        SD->getFragment()->getParent()->getSection()))
+  if (!getContext().getAsmInfo()->isSectionAtomizableBySymbols(
+          SD->getFragment()->getParent()->getSection()))
     return nullptr;
 
   // Otherwise, return the atom for the containing fragment.

lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.h

@@ -21,7 +21,8 @@
 namespace llvm {
 
   class ARMMCAsmInfoDarwin : public MCAsmInfoDarwin {
-    void anchor() override;
+    virtual void anchor();
+
   public:
     explicit ARMMCAsmInfoDarwin(StringRef TT);
   };

lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.h

@@ -21,7 +21,8 @@ namespace llvm {
 class Triple;
 
   class PPCMCAsmInfoDarwin : public MCAsmInfoDarwin {
-    void anchor() override;
+    virtual void anchor();
+
   public:
     explicit PPCMCAsmInfoDarwin(bool is64Bit, const Triple&);
   };

lib/Target/TargetLoweringObjectFile.cpp

@@ -270,12 +270,6 @@ SectionForGlobal(const GlobalValue *GV, SectionKind Kind, Mangler &Mang,
   return SelectSectionForGlobal(GV, Kind, Mang, TM);
 }
 
-bool TargetLoweringObjectFile::isSectionAtomizableBySymbols(
-    const MCSection &Section) const {
-  return false;
-}
-
-
 /// getSectionForConstant - Given a mergable constant with the
 /// specified size and relocation information, return a section that it
 /// should be placed in.

lib/Target/TargetMachine.cpp

@@ -21,6 +21,7 @@
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCCodeGenInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCSectionMachO.h"
 #include "llvm/MC/MCTargetOptions.h"
 #include "llvm/MC/SectionKind.h"
 #include "llvm/Support/CommandLine.h"
@@ -169,6 +170,19 @@ void TargetMachine::setDataSections(bool V) {
   Options.DataSections = V;
 }
 
+static bool canUsePrivateLabel(const MCAsmInfo &AsmInfo,
+                               const MCSection &Section) {
+  if (!AsmInfo.isSectionAtomizableBySymbols(Section))
+    return true;
+
+  // If it is not dead stripped, it is safe to use private labels.
+  const MCSectionMachO &SMO = cast<MCSectionMachO>(Section);
+  if (SMO.hasAttribute(MachO::S_ATTR_NO_DEAD_STRIP))
+    return true;
+
+  return false;
+}
+
 void TargetMachine::getNameWithPrefix(SmallVectorImpl<char> &Name,
                                       const GlobalValue *GV, Mangler &Mang,
                                       bool MayAlwaysUsePrivate) const {
@@ -182,7 +196,7 @@ void TargetMachine::getNameWithPrefix(SmallVectorImpl<char> &Name,
   const TargetLoweringObjectFile &TLOF =
       getSubtargetImpl()->getTargetLowering()->getObjFileLowering();
   const MCSection *TheSection = TLOF.SectionForGlobal(GV, GVKind, Mang, *this);
-  bool CannotUsePrivateLabel = TLOF.isSectionAtomizableBySymbols(*TheSection);
+  bool CannotUsePrivateLabel = !canUsePrivateLabel(*AsmInfo, *TheSection);
   Mang.getNameWithPrefix(Name, GV, CannotUsePrivateLabel);
 }
 

lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp

@@ -790,26 +790,6 @@ class DarwinX86_64AsmBackend : public DarwinX86AsmBackend {
     return SMO.getType() == MachO::S_CSTRING_LITERALS;
   }
 
-  bool isSectionAtomizable(const MCSection &Section) const override {
-    const MCSectionMachO &SMO = static_cast<const MCSectionMachO&>(Section);
-    // Fixed sized data sections are uniqued, they cannot be diced into atoms.
-    switch (SMO.getType()) {
-    default:
-      return true;
-
-    case MachO::S_4BYTE_LITERALS:
-    case MachO::S_8BYTE_LITERALS:
-    case MachO::S_16BYTE_LITERALS:
-    case MachO::S_LITERAL_POINTERS:
-    case MachO::S_NON_LAZY_SYMBOL_POINTERS:
-    case MachO::S_LAZY_SYMBOL_POINTERS:
-    case MachO::S_MOD_INIT_FUNC_POINTERS:
-    case MachO::S_MOD_TERM_FUNC_POINTERS:
-    case MachO::S_INTERPOSING:
-      return false;
-    }
-  }
-
   /// \brief Generate the compact unwind encoding for the CFI instructions.
   uint32_t generateCompactUnwindEncoding(
                              ArrayRef<MCCFIInstruction> Instrs) const override {

lib/Target/X86/MCTargetDesc/X86MCAsmInfo.h

@@ -23,7 +23,8 @@ namespace llvm {
   class Triple;
 
   class X86MCAsmInfoDarwin : public MCAsmInfoDarwin {
-    void anchor() override;
+    virtual void anchor();
+
   public:
     explicit X86MCAsmInfoDarwin(const Triple &Triple);
   };