[llvm] r226503 - Add r224985 back with fixes.

Rafael Espindola rafael.espindola at gmail.com
Mon Jan 19 13:11:14 PST 2015


Author: rafael
Date: Mon Jan 19 15:11:14 2015
New Revision: 226503

URL: http://llvm.org/viewvc/llvm-project?rev=226503&view=rev
Log:
Add r224985 back with fixes.

The fixes are to note that AArch64 has additional restrictions on when local
relocations can be used. In particular, ld64 requires that relocations to
cstring/cfstrings use linker visible symbols.

Original message:

In an assembly expression like

bar:
  .long L0 + 1

the intended semantics is that bar will contain a pointer one byte past L0.

In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.

The solution used in ELF to use relocation with symbols if there is a non-zero
addend.

In MachO before this patch we would just keep all symbols in some sections.

This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.

This patch implements the non-zero addend logic for MachO too.

Added:
    llvm/trunk/test/MC/MachO/AArch64/mergeable.s
    llvm/trunk/test/MC/MachO/x86_64-mergeable.s
Modified:
    llvm/trunk/include/llvm/MC/MCAsmBackend.h
    llvm/trunk/include/llvm/MC/MCAssembler.h
    llvm/trunk/include/llvm/MC/MCMachObjectWriter.h
    llvm/trunk/include/llvm/MC/MCObjectWriter.h
    llvm/trunk/lib/MC/ELFObjectWriter.cpp
    llvm/trunk/lib/MC/MCAsmInfoDarwin.cpp
    llvm/trunk/lib/MC/MCAssembler.cpp
    llvm/trunk/lib/MC/MachObjectWriter.cpp
    llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp
    llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
    llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp
    llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp
    llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp
    llvm/trunk/lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp
    llvm/trunk/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
    llvm/trunk/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
    llvm/trunk/test/MC/MachO/x86_64-symbols.s

Modified: llvm/trunk/include/llvm/MC/MCAsmBackend.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCAsmBackend.h?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCAsmBackend.h (original)
+++ llvm/trunk/include/llvm/MC/MCAsmBackend.h Mon Jan 19 15:11:14 2015
@@ -61,12 +61,6 @@ public:
   /// markers. If not, data region directives will be ignored.
   bool hasDataInCodeSupport() const { return HasDataInCodeSupport; }
 
-  /// doesSectionRequireSymbols - Check whether the given section requires that
-  /// all symbols (even temporaries) have symbol table entries.
-  virtual bool doesSectionRequireSymbols(const MCSection &Section) const {
-    return false;
-  }
-
   /// @name Target Fixup Interfaces
   /// @{
 

Modified: llvm/trunk/include/llvm/MC/MCAssembler.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCAssembler.h?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCAssembler.h (original)
+++ llvm/trunk/include/llvm/MC/MCAssembler.h Mon Jan 19 15:11:14 2015
@@ -11,6 +11,7 @@
 #define LLVM_MC_MCASSEMBLER_H
 
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/PointerIntPair.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallString.h"
@@ -881,6 +882,8 @@ private:
 
   iplist<MCSymbolData> Symbols;
 
+  DenseSet<const MCSymbol *> LocalsUsedInReloc;
+
   /// The map of sections to their associated assembler backend data.
   //
   // FIXME: Avoid this indirection?
@@ -980,6 +983,9 @@ private:
                                         MCFragment &F, const MCFixup &Fixup);
 
 public:
+  void addLocalUsedInReloc(const MCSymbol &Sym);
+  bool isLocalUsedInReloc(const MCSymbol &Sym) const;
+
   /// Compute the effective fragment size assuming it is laid out at the given
   /// \p SectionAddress and \p FragmentOffset.
   uint64_t computeFragmentSize(const MCAsmLayout &Layout,

Modified: llvm/trunk/include/llvm/MC/MCMachObjectWriter.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCMachObjectWriter.h?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCMachObjectWriter.h (original)
+++ llvm/trunk/include/llvm/MC/MCMachObjectWriter.h Mon Jan 19 15:11:14 2015
@@ -68,12 +68,10 @@ public:
   /// @name API
   /// @{
 
-  virtual void RecordRelocation(MachObjectWriter *Writer,
-                                const MCAssembler &Asm,
+  virtual void RecordRelocation(MachObjectWriter *Writer, MCAssembler &Asm,
                                 const MCAsmLayout &Layout,
                                 const MCFragment *Fragment,
-                                const MCFixup &Fixup,
-                                MCValue Target,
+                                const MCFixup &Fixup, MCValue Target,
                                 uint64_t &FixedValue) = 0;
 
   /// @}
@@ -97,8 +95,14 @@ class MachObjectWriter : public MCObject
   /// @name Relocation Data
   /// @{
 
-  llvm::DenseMap<const MCSectionData*,
-                 std::vector<MachO::any_relocation_info> > Relocations;
+  struct RelAndSymbol {
+    const MCSymbolData *Sym;
+    MachO::any_relocation_info MRE;
+    RelAndSymbol(const MCSymbolData *Sym, const MachO::any_relocation_info &MRE)
+        : Sym(Sym), MRE(MRE) {}
+  };
+
+  llvm::DenseMap<const MCSectionData *, std::vector<RelAndSymbol>> Relocations;
   llvm::DenseMap<const MCSectionData*, unsigned> IndirectSymBase;
 
   /// @}
@@ -213,9 +217,15 @@ public:
   //  - Input errors, where something cannot be correctly encoded. 'as' allows
   //    these through in many cases.
 
-  void addRelocation(const MCSectionData *SD,
+  // Add a relocation to be output in the object file. At the time this is
+  // called, the symbol indexes are not know, so if the relocation refers
+  // to a symbol it should be passed as \p RelSymbol so that it can be updated
+  // afterwards. If the relocation doesn't refer to a symbol, nullptr should be
+  // used.
+  void addRelocation(const MCSymbolData *RelSymbol, const MCSectionData *SD,
                      MachO::any_relocation_info &MRE) {
-    Relocations[SD].push_back(MRE);
+    RelAndSymbol P(RelSymbol, MRE);
+    Relocations[SD].push_back(P);
   }
 
   void RecordScatteredRelocation(const MCAssembler &Asm,
@@ -231,7 +241,7 @@ public:
                             const MCFixup &Fixup, MCValue Target,
                             uint64_t &FixedValue);
 
-  void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
+  void RecordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
                         const MCFragment *Fragment, const MCFixup &Fixup,
                         MCValue Target, bool &IsPCRel,
                         uint64_t &FixedValue) override;

Modified: llvm/trunk/include/llvm/MC/MCObjectWriter.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCObjectWriter.h?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCObjectWriter.h (original)
+++ llvm/trunk/include/llvm/MC/MCObjectWriter.h Mon Jan 19 15:11:14 2015
@@ -76,12 +76,10 @@ public:
   /// post layout binding. The implementation is responsible for storing
   /// information about the relocation so that it can be emitted during
   /// WriteObject().
-  virtual void RecordRelocation(const MCAssembler &Asm,
-                                const MCAsmLayout &Layout,
+  virtual void RecordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
                                 const MCFragment *Fragment,
                                 const MCFixup &Fixup, MCValue Target,
-                                bool &IsPCRel,
-                                uint64_t &FixedValue) = 0;
+                                bool &IsPCRel, uint64_t &FixedValue) = 0;
 
   /// \brief Check whether the difference (A - B) between two symbol
   /// references is fully resolved.

Modified: llvm/trunk/lib/MC/ELFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/ELFObjectWriter.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/MC/ELFObjectWriter.cpp (original)
+++ llvm/trunk/lib/MC/ELFObjectWriter.cpp Mon Jan 19 15:11:14 2015
@@ -219,7 +219,7 @@ class ELFObjectWriter : public MCObjectW
                                   const MCSymbolData *SD, uint64_t C,
                                   unsigned Type) const;
 
-    void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
+    void RecordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
                           const MCFragment *Fragment, const MCFixup &Fixup,
                           MCValue Target, bool &IsPCRel,
                           uint64_t &FixedValue) override;
@@ -789,13 +789,11 @@ static const MCSymbol *getWeakRef(const
   return nullptr;
 }
 
-void ELFObjectWriter::RecordRelocation(const MCAssembler &Asm,
+void ELFObjectWriter::RecordRelocation(MCAssembler &Asm,
                                        const MCAsmLayout &Layout,
                                        const MCFragment *Fragment,
-                                       const MCFixup &Fixup,
-                                       MCValue Target,
-                                       bool &IsPCRel,
-                                       uint64_t &FixedValue) {
+                                       const MCFixup &Fixup, MCValue Target,
+                                       bool &IsPCRel, uint64_t &FixedValue) {
   const MCSectionData *FixupSection = Fragment->getParent();
   uint64_t C = Target.getConstant();
   uint64_t FixupOffset = Layout.getFragmentOffset(Fragment) + Fixup.getOffset();

Modified: llvm/trunk/lib/MC/MCAsmInfoDarwin.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCAsmInfoDarwin.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCAsmInfoDarwin.cpp (original)
+++ llvm/trunk/lib/MC/MCAsmInfoDarwin.cpp Mon Jan 19 15:11:14 2015
@@ -27,22 +27,7 @@ bool MCAsmInfoDarwin::isSectionAtomizabl
   // 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)
+  if (SMO.getType() == MachO::S_CSTRING_LITERALS)
     return false;
 
   if (SMO.getSegmentName() == "__DATA" && SMO.getSectionName() == "__cfstring")

Modified: llvm/trunk/lib/MC/MCAssembler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCAssembler.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCAssembler.cpp (original)
+++ llvm/trunk/lib/MC/MCAssembler.cpp Mon Jan 19 15:11:14 2015
@@ -435,6 +435,16 @@ bool MCAssembler::isThumbFunc(const MCSy
   return true;
 }
 
+void MCAssembler::addLocalUsedInReloc(const MCSymbol &Sym) {
+  assert(Sym.isTemporary());
+  LocalsUsedInReloc.insert(&Sym);
+}
+
+bool MCAssembler::isLocalUsedInReloc(const MCSymbol &Sym) const {
+  assert(Sym.isTemporary());
+  return LocalsUsedInReloc.count(&Sym);
+}
+
 bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const {
   // Non-temporary labels should always be visible to the linker.
   if (!Symbol.isTemporary())
@@ -444,8 +454,10 @@ bool MCAssembler::isSymbolLinkerVisible(
   if (!Symbol.isInSection())
     return false;
 
-  // Otherwise, check if the section requires symbols even for temporary labels.
-  return getBackend().doesSectionRequireSymbols(Symbol.getSection());
+  if (isLocalUsedInReloc(Symbol))
+    return true;
+
+  return false;
 }
 
 const MCSymbolData *MCAssembler::getAtom(const MCSymbolData *SD) const {

Modified: llvm/trunk/lib/MC/MachObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MachObjectWriter.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MachObjectWriter.cpp (original)
+++ llvm/trunk/lib/MC/MachObjectWriter.cpp Mon Jan 19 15:11:14 2015
@@ -448,14 +448,11 @@ void MachObjectWriter::WriteLinkerOption
   assert(OS.tell() - Start == Size);
 }
 
-
-void MachObjectWriter::RecordRelocation(const MCAssembler &Asm,
+void MachObjectWriter::RecordRelocation(MCAssembler &Asm,
                                         const MCAsmLayout &Layout,
                                         const MCFragment *Fragment,
-                                        const MCFixup &Fixup,
-                                        MCValue Target,
-                                        bool &IsPCRel,
-                                        uint64_t &FixedValue) {
+                                        const MCFixup &Fixup, MCValue Target,
+                                        bool &IsPCRel, uint64_t &FixedValue) {
   TargetObjectWriter->RecordRelocation(this, Asm, Layout, Fragment, Fixup,
                                        Target, FixedValue);
 }
@@ -616,6 +613,22 @@ void MachObjectWriter::ComputeSymbolTabl
     ExternalSymbolData[i].SymbolData->setIndex(Index++);
   for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i)
     UndefinedSymbolData[i].SymbolData->setIndex(Index++);
+
+  for (const MCSectionData &SD : Asm) {
+    std::vector<RelAndSymbol> &Relocs = Relocations[&SD];
+    for (RelAndSymbol &Rel : Relocs) {
+      if (!Rel.Sym)
+        continue;
+
+      // Set the Index and the IsExtern bit.
+      unsigned Index = Rel.Sym->getIndex();
+      assert(isInt<24>(Index));
+      if (IsLittleEndian)
+        Rel.MRE.r_word1 = (Rel.MRE.r_word1 & (-1 << 24)) | Index | (1 << 27);
+      else
+        Rel.MRE.r_word1 = (Rel.MRE.r_word1 & 0xff) | Index << 8 | (1 << 4);
+    }
+  }
 }
 
 void MachObjectWriter::computeSectionAddresses(const MCAssembler &Asm,
@@ -662,10 +675,6 @@ void MachObjectWriter::ExecutePostLayout
   // Mark symbol difference expressions in variables (from .set or = directives)
   // as absolute.
   markAbsoluteVariableSymbols(Asm, Layout);
-
-  // Compute symbol table information and bind symbol indices.
-  ComputeSymbolTable(Asm, LocalSymbolData, ExternalSymbolData,
-                     UndefinedSymbolData);
 }
 
 bool MachObjectWriter::
@@ -749,6 +758,10 @@ IsSymbolRefDifferenceFullyResolvedImpl(c
 
 void MachObjectWriter::WriteObject(MCAssembler &Asm,
                                    const MCAsmLayout &Layout) {
+  // Compute symbol table information and bind symbol indices.
+  ComputeSymbolTable(Asm, LocalSymbolData, ExternalSymbolData,
+                     UndefinedSymbolData);
+
   unsigned NumSections = Asm.size();
   const MCAssembler::VersionMinInfoType &VersionInfo =
     Layout.getAssembler().getVersionMinInfo();
@@ -839,7 +852,7 @@ void MachObjectWriter::WriteObject(MCAss
   uint64_t RelocTableEnd = SectionDataStart + SectionDataFileSize;
   for (MCAssembler::const_iterator it = Asm.begin(),
          ie = Asm.end(); it != ie; ++it) {
-    std::vector<MachO::any_relocation_info> &Relocs = Relocations[it];
+    std::vector<RelAndSymbol> &Relocs = Relocations[it];
     unsigned NumRelocs = Relocs.size();
     uint64_t SectionStart = SectionDataStart + getSectionAddress(it);
     WriteSection(Asm, Layout, *it, SectionStart, RelocTableEnd, NumRelocs);
@@ -933,10 +946,10 @@ void MachObjectWriter::WriteObject(MCAss
          ie = Asm.end(); it != ie; ++it) {
     // Write the section relocation entries, in reverse order to match 'as'
     // (approximately, the exact algorithm is more complicated than this).
-    std::vector<MachO::any_relocation_info> &Relocs = Relocations[it];
+    std::vector<RelAndSymbol> &Relocs = Relocations[it];
     for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
-      Write32(Relocs[e - i - 1].r_word0);
-      Write32(Relocs[e - i - 1].r_word1);
+      Write32(Relocs[e - i - 1].MRE.r_word0);
+      Write32(Relocs[e - i - 1].MRE.r_word1);
     }
   }
 

Modified: llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp (original)
+++ llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp Mon Jan 19 15:11:14 2015
@@ -175,7 +175,7 @@ public:
                                               const MCFragment &FB, bool InSet,
                                               bool IsPCRel) const override;
 
-  void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
+  void RecordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
                         const MCFragment *Fragment, const MCFixup &Fixup,
                         MCValue Target, bool &IsPCRel,
                         uint64_t &FixedValue) override;
@@ -661,13 +661,9 @@ bool WinCOFFObjectWriter::IsSymbolRefDif
                                                                 InSet, IsPCRel);
 }
 
-void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
-                                           const MCAsmLayout &Layout,
-                                           const MCFragment *Fragment,
-                                           const MCFixup &Fixup,
-                                           MCValue Target,
-                                           bool &IsPCRel,
-                                           uint64_t &FixedValue) {
+void WinCOFFObjectWriter::RecordRelocation(
+    MCAssembler &Asm, const MCAsmLayout &Layout, const MCFragment *Fragment,
+    const MCFixup &Fixup, MCValue Target, bool &IsPCRel, uint64_t &FixedValue) {
   assert(Target.getSymA() && "Relocation must reference a symbol!");
 
   const MCSymbol &Symbol = Target.getSymA()->getSymbol();

Modified: llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp Mon Jan 19 15:11:14 2015
@@ -317,42 +317,6 @@ public:
                                          MachO::CPU_SUBTYPE_ARM64_ALL);
   }
 
-  bool doesSectionRequireSymbols(const MCSection &Section) const override {
-    // Any section for which the linker breaks things into atoms needs to
-    // preserve symbols, including assembler local symbols, to identify
-    // those atoms. These sections are:
-    // Sections of type:
-    //
-    //    S_CSTRING_LITERALS  (e.g. __cstring)
-    //    S_LITERAL_POINTERS  (e.g.  objc selector pointers)
-    //    S_16BYTE_LITERALS, S_8BYTE_LITERALS, S_4BYTE_LITERALS
-    //
-    // Sections named:
-    //
-    //    __TEXT,__eh_frame
-    //    __TEXT,__ustring
-    //    __DATA,__cfstring
-    //    __DATA,__objc_classrefs
-    //    __DATA,__objc_catlist
-    //
-    // FIXME: It would be better if the compiler used actual linker local
-    // symbols for each of these sections rather than preserving what
-    // are ostensibly assembler local symbols.
-    const MCSectionMachO &SMO = static_cast<const MCSectionMachO &>(Section);
-    return (SMO.getType() == MachO::S_CSTRING_LITERALS ||
-            SMO.getType() == MachO::S_4BYTE_LITERALS ||
-            SMO.getType() == MachO::S_8BYTE_LITERALS ||
-            SMO.getType() == MachO::S_16BYTE_LITERALS ||
-            SMO.getType() == MachO::S_LITERAL_POINTERS ||
-            (SMO.getSegmentName() == "__TEXT" &&
-             (SMO.getSectionName() == "__eh_frame" ||
-              SMO.getSectionName() == "__ustring")) ||
-            (SMO.getSegmentName() == "__DATA" &&
-             (SMO.getSectionName() == "__cfstring" ||
-              SMO.getSectionName() == "__objc_classrefs" ||
-              SMO.getSectionName() == "__objc_catlist")));
-  }
-
   /// \brief Generate the compact unwind encoding from the CFI directives.
   uint32_t generateCompactUnwindEncoding(
                              ArrayRef<MCCFIInstruction> Instrs) const override {

Modified: llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp Mon Jan 19 15:11:14 2015
@@ -10,6 +10,7 @@
 #include "MCTargetDesc/AArch64FixupKinds.h"
 #include "MCTargetDesc/AArch64MCTargetDesc.h"
 #include "llvm/ADT/Twine.h"
+#include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCAsmLayout.h"
 #include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCContext.h"
@@ -33,7 +34,7 @@ public:
       : MCMachObjectTargetWriter(true /* is64Bit */, CPUType, CPUSubtype,
                                  /*UseAggressiveSymbolFolding=*/true) {}
 
-  void RecordRelocation(MachObjectWriter *Writer, const MCAssembler &Asm,
+  void RecordRelocation(MachObjectWriter *Writer, MCAssembler &Asm,
                         const MCAsmLayout &Layout, const MCFragment *Fragment,
                         const MCFixup &Fixup, MCValue Target,
                         uint64_t &FixedValue) override;
@@ -112,8 +113,32 @@ bool AArch64MachObjectWriter::getAArch64
   }
 }
 
+static bool canUseLocalRelocation(const MCSectionMachO &Section,
+                                  const MCSymbol &Symbol, unsigned Log2Size) {
+  // Debug info sections can use local relocations.
+  if (Section.hasAttribute(MachO::S_ATTR_DEBUG))
+    return true;
+
+  // Otherwise, only pointer sized relocations are supported.
+  if (Log2Size != 3)
+    return false;
+
+  // But only if they don't point to a few forbidden sections.
+  if (!Symbol.isInSection())
+    return true;
+  const MCSectionMachO &RefSec = cast<MCSectionMachO>(Symbol.getSection());
+  if (RefSec.getType() == MachO::S_CSTRING_LITERALS)
+    return false;
+
+  if (RefSec.getSegmentName() == "__DATA" &&
+      RefSec.getSectionName() == "__cfstring")
+    return false;
+
+  return true;
+}
+
 void AArch64MachObjectWriter::RecordRelocation(
-    MachObjectWriter *Writer, const MCAssembler &Asm, const MCAsmLayout &Layout,
+    MachObjectWriter *Writer, MCAssembler &Asm, const MCAsmLayout &Layout,
     const MCFragment *Fragment, const MCFixup &Fixup, MCValue Target,
     uint64_t &FixedValue) {
   unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, Fixup.getKind());
@@ -123,9 +148,9 @@ void AArch64MachObjectWriter::RecordRelo
   unsigned Log2Size = 0;
   int64_t Value = 0;
   unsigned Index = 0;
-  unsigned IsExtern = 0;
   unsigned Type = 0;
   unsigned Kind = Fixup.getKind();
+  const MCSymbolData *RelSymbol = nullptr;
 
   FixupOffset += Fixup.getOffset();
 
@@ -171,10 +196,8 @@ void AArch64MachObjectWriter::RecordRelo
     // FIXME: Should this always be extern?
     // SymbolNum of 0 indicates the absolute section.
     Type = MachO::ARM64_RELOC_UNSIGNED;
-    Index = 0;
 
     if (IsPCRel) {
-      IsExtern = 1;
       Asm.getContext().FatalError(Fixup.getLoc(),
                                   "PC relative absolute relocation!");
 
@@ -198,15 +221,12 @@ void AArch64MachObjectWriter::RecordRelo
         Layout.getSymbolOffset(&B_SD) ==
             Layout.getFragmentOffset(Fragment) + Fixup.getOffset()) {
       // SymB is the PC, so use a PC-rel pointer-to-GOT relocation.
-      Index = A_Base->getIndex();
-      IsExtern = 1;
       Type = MachO::ARM64_RELOC_POINTER_TO_GOT;
       IsPCRel = 1;
       MachO::any_relocation_info MRE;
       MRE.r_word0 = FixupOffset;
-      MRE.r_word1 = ((Index << 0) | (IsPCRel << 24) | (Log2Size << 25) |
-                     (IsExtern << 27) | (Type << 28));
-      Writer->addRelocation(Fragment->getParent(), MRE);
+      MRE.r_word1 = (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
+      Writer->addRelocation(A_Base, Fragment->getParent(), MRE);
       return;
     } else if (Target.getSymA()->getKind() != MCSymbolRefExpr::VK_None ||
                Target.getSymB()->getKind() != MCSymbolRefExpr::VK_None)
@@ -252,26 +272,31 @@ void AArch64MachObjectWriter::RecordRelo
                   ? 0
                   : Writer->getSymbolAddress(B_Base, Layout));
 
-    Index = A_Base->getIndex();
-    IsExtern = 1;
     Type = MachO::ARM64_RELOC_UNSIGNED;
 
     MachO::any_relocation_info MRE;
     MRE.r_word0 = FixupOffset;
-    MRE.r_word1 = ((Index << 0) | (IsPCRel << 24) | (Log2Size << 25) |
-                   (IsExtern << 27) | (Type << 28));
-    Writer->addRelocation(Fragment->getParent(), MRE);
+    MRE.r_word1 = (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
+    Writer->addRelocation(A_Base, Fragment->getParent(), MRE);
 
-    Index = B_Base->getIndex();
-    IsExtern = 1;
+    RelSymbol = B_Base;
     Type = MachO::ARM64_RELOC_SUBTRACTOR;
   } else { // A + constant
     const MCSymbol *Symbol = &Target.getSymA()->getSymbol();
-    const MCSymbolData &SD = Asm.getSymbolData(*Symbol);
-    const MCSymbolData *Base = Asm.getAtom(&SD);
     const MCSectionMachO &Section = static_cast<const MCSectionMachO &>(
         Fragment->getParent()->getSection());
 
+    bool CanUseLocalRelocation =
+        canUseLocalRelocation(Section, *Symbol, Log2Size);
+    if (Symbol->isTemporary() && (Value || !CanUseLocalRelocation)) {
+      const MCSection &Sec = Symbol->getSection();
+      if (!Asm.getContext().getAsmInfo()->isSectionAtomizableBySymbols(Sec))
+        Asm.addLocalUsedInReloc(*Symbol);
+    }
+
+    const MCSymbolData &SD = Asm.getSymbolData(*Symbol);
+    const MCSymbolData *Base = Asm.getAtom(&SD);
+
     // If the symbol is a variable and we weren't able to get a Base for it
     // (i.e., it's not in the symbol table associated with a section) resolve
     // the relocation based its expansion instead.
@@ -310,16 +335,13 @@ void AArch64MachObjectWriter::RecordRelo
     // sections, and for pointer-sized relocations (.quad), we allow section
     // relocations.  It's code sections that run into trouble.
     if (Base) {
-      Index = Base->getIndex();
-      IsExtern = 1;
+      RelSymbol = Base;
 
       // Add the local offset, if needed.
       if (Base != &SD)
         Value += Layout.getSymbolOffset(&SD) - Layout.getSymbolOffset(Base);
     } else if (Symbol->isInSection()) {
-      // Pointer-sized relocations can use a local relocation. Otherwise,
-      // we have to be in a debug info section.
-      if (!Section.hasAttribute(MachO::S_ATTR_DEBUG) && Log2Size != 3)
+      if (!CanUseLocalRelocation)
         Asm.getContext().FatalError(
             Fixup.getLoc(),
             "unsupported relocation of local symbol '" + Symbol->getName() +
@@ -329,7 +351,6 @@ void AArch64MachObjectWriter::RecordRelo
       const MCSectionData &SymSD =
           Asm.getSectionData(SD.getSymbol().getSection());
       Index = SymSD.getOrdinal() + 1;
-      IsExtern = 0;
       Value += Writer->getSymbolAddress(&SD, Layout);
 
       if (IsPCRel)
@@ -362,16 +383,16 @@ void AArch64MachObjectWriter::RecordRelo
 
     MachO::any_relocation_info MRE;
     MRE.r_word0 = FixupOffset;
-    MRE.r_word1 = ((Index << 0) | (IsPCRel << 24) | (Log2Size << 25) |
-                   (IsExtern << 27) | (Type << 28));
-    Writer->addRelocation(Fragment->getParent(), MRE);
+    MRE.r_word1 =
+        (Index << 0) | (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
+    Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
 
     // Now set up the Addend relocation.
     Type = MachO::ARM64_RELOC_ADDEND;
     Index = Value;
+    RelSymbol = nullptr;
     IsPCRel = 0;
     Log2Size = 2;
-    IsExtern = 0;
 
     // Put zero into the instruction itself. The addend is in the relocation.
     Value = 0;
@@ -383,9 +404,9 @@ void AArch64MachObjectWriter::RecordRelo
   // struct relocation_info (8 bytes)
   MachO::any_relocation_info MRE;
   MRE.r_word0 = FixupOffset;
-  MRE.r_word1 = ((Index << 0) | (IsPCRel << 24) | (Log2Size << 25) |
-                 (IsExtern << 27) | (Type << 28));
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  MRE.r_word1 =
+      (Index << 0) | (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
+  Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
 }
 
 MCObjectWriter *llvm::createAArch64MachObjectWriter(raw_ostream &OS,

Modified: llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp (original)
+++ llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp Mon Jan 19 15:11:14 2015
@@ -54,10 +54,10 @@ public:
     : MCMachObjectTargetWriter(Is64Bit, CPUType, CPUSubtype,
                                /*UseAggressiveSymbolFolding=*/true) {}
 
-  void RecordRelocation(MachObjectWriter *Writer,
-                        const MCAssembler &Asm, const MCAsmLayout &Layout,
-                        const MCFragment *Fragment, const MCFixup &Fixup,
-                        MCValue Target, uint64_t &FixedValue) override;
+  void RecordRelocation(MachObjectWriter *Writer, MCAssembler &Asm,
+                        const MCAsmLayout &Layout, const MCFragment *Fragment,
+                        const MCFixup &Fixup, MCValue Target,
+                        uint64_t &FixedValue) override;
 };
 }
 
@@ -232,7 +232,7 @@ RecordARMScatteredHalfRelocation(MachObj
                    (IsPCRel               << 30) |
                    MachO::R_SCATTERED);
     MRE.r_word1 = Value2;
-    Writer->addRelocation(Fragment->getParent(), MRE);
+    Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
   }
 
   MachO::any_relocation_info MRE;
@@ -243,7 +243,7 @@ RecordARMScatteredHalfRelocation(MachObj
                  (IsPCRel     << 30) |
                  MachO::R_SCATTERED);
   MRE.r_word1 = Value;
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
 }
 
 void ARMMachObjectWriter::RecordARMScatteredRelocation(MachObjectWriter *Writer,
@@ -297,7 +297,7 @@ void ARMMachObjectWriter::RecordARMScatt
                    (IsPCRel               << 30) |
                    MachO::R_SCATTERED);
     MRE.r_word1 = Value2;
-    Writer->addRelocation(Fragment->getParent(), MRE);
+    Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
   }
 
   MachO::any_relocation_info MRE;
@@ -307,7 +307,7 @@ void ARMMachObjectWriter::RecordARMScatt
                  (IsPCRel     << 30) |
                  MachO::R_SCATTERED);
   MRE.r_word1 = Value;
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
 }
 
 bool ARMMachObjectWriter::requiresExternRelocation(MachObjectWriter *Writer,
@@ -351,11 +351,10 @@ bool ARMMachObjectWriter::requiresExtern
 }
 
 void ARMMachObjectWriter::RecordRelocation(MachObjectWriter *Writer,
-                                           const MCAssembler &Asm,
+                                           MCAssembler &Asm,
                                            const MCAsmLayout &Layout,
                                            const MCFragment *Fragment,
-                                           const MCFixup &Fixup,
-                                           MCValue Target,
+                                           const MCFixup &Fixup, MCValue Target,
                                            uint64_t &FixedValue) {
   unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, Fixup.getKind());
   unsigned Log2Size;
@@ -401,8 +400,8 @@ void ARMMachObjectWriter::RecordRelocati
   // See <reloc.h>.
   uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
   unsigned Index = 0;
-  unsigned IsExtern = 0;
   unsigned Type = 0;
+  const MCSymbolData *RelSymbol = nullptr;
 
   if (Target.isAbsolute()) { // constant
     // FIXME!
@@ -422,8 +421,7 @@ void ARMMachObjectWriter::RecordRelocati
     // Check whether we need an external or internal relocation.
     if (requiresExternRelocation(Writer, Asm, *Fragment, RelocType, SD,
                                  FixedValue)) {
-      IsExtern = 1;
-      Index = SD->getIndex();
+      RelSymbol = SD;
 
       // For external relocations, make sure to offset the fixup value to
       // compensate for the addend of the symbol address, if it was
@@ -447,11 +445,8 @@ void ARMMachObjectWriter::RecordRelocati
   // struct relocation_info (8 bytes)
   MachO::any_relocation_info MRE;
   MRE.r_word0 = FixupOffset;
-  MRE.r_word1 = ((Index     <<  0) |
-                 (IsPCRel   << 24) |
-                 (Log2Size  << 25) |
-                 (IsExtern  << 27) |
-                 (Type      << 28));
+  MRE.r_word1 =
+      (Index << 0) | (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
 
   // Even when it's not a scattered relocation, movw/movt always uses
   // a PAIR relocation.
@@ -476,10 +471,10 @@ void ARMMachObjectWriter::RecordRelocati
                        (Log2Size              << 25) |
                        (MachO::ARM_RELOC_PAIR << 28));
 
-    Writer->addRelocation(Fragment->getParent(), MREPair);
+    Writer->addRelocation(nullptr, Fragment->getParent(), MREPair);
   }
 
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
 }
 
 MCObjectWriter *llvm::createARMMachObjectWriter(raw_ostream &OS,

Modified: llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp Mon Jan 19 15:11:14 2015
@@ -41,7 +41,7 @@ public:
       : MCMachObjectTargetWriter(Is64Bit, CPUType, CPUSubtype,
                                  /*UseAggressiveSymbolFolding=*/Is64Bit) {}
 
-  void RecordRelocation(MachObjectWriter *Writer, const MCAssembler &Asm,
+  void RecordRelocation(MachObjectWriter *Writer, MCAssembler &Asm,
                         const MCAsmLayout &Layout, const MCFragment *Fragment,
                         const MCFixup &Fixup, MCValue Target,
                         uint64_t &FixedValue) override {
@@ -282,7 +282,7 @@ bool PPCMachObjectWriter::RecordScattere
     MachO::any_relocation_info MRE;
     makeScatteredRelocationInfo(MRE, other_half, MachO::GENERIC_RELOC_PAIR,
                                 Log2Size, IsPCRel, Value2);
-    Writer->addRelocation(Fragment->getParent(), MRE);
+    Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
   } else {
     // If the offset is more than 24-bits, it won't fit in a scattered
     // relocation offset field, so we fall back to using a non-scattered
@@ -296,7 +296,7 @@ bool PPCMachObjectWriter::RecordScattere
   }
   MachO::any_relocation_info MRE;
   makeScatteredRelocationInfo(MRE, FixupOffset, Type, Log2Size, IsPCRel, Value);
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
   return true;
 }
 
@@ -331,9 +331,9 @@ void PPCMachObjectWriter::RecordPPCReloc
   // See <reloc.h>.
   const uint32_t FixupOffset = getFixupOffset(Layout, Fragment, Fixup);
   unsigned Index = 0;
-  unsigned IsExtern = 0;
   unsigned Type = RelocType;
 
+  const MCSymbolData *RelSymbol = nullptr;
   if (Target.isAbsolute()) { // constant
                              // SymbolNum of 0 indicates the absolute section.
                              //
@@ -355,8 +355,7 @@ void PPCMachObjectWriter::RecordPPCReloc
 
     // Check whether we need an external or internal relocation.
     if (Writer->doesSymbolRequireExternRelocation(SD)) {
-      IsExtern = 1;
-      Index = SD->getIndex();
+      RelSymbol = SD;
       // For external relocations, make sure to offset the fixup value to
       // compensate for the addend of the symbol address, if it was
       // undefined. This occurs with weak definitions, for example.
@@ -375,9 +374,8 @@ void PPCMachObjectWriter::RecordPPCReloc
 
   // struct relocation_info (8 bytes)
   MachO::any_relocation_info MRE;
-  makeRelocationInfo(MRE, FixupOffset, Index, IsPCRel, Log2Size, IsExtern,
-                     Type);
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  makeRelocationInfo(MRE, FixupOffset, Index, IsPCRel, Log2Size, false, Type);
+  Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
 }
 
 MCObjectWriter *llvm::createPPCMachObjectWriter(raw_ostream &OS, bool Is64Bit,

Modified: llvm/trunk/lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp (original)
+++ llvm/trunk/lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp Mon Jan 19 15:11:14 2015
@@ -29,7 +29,7 @@ public:
                                 const MCAsmLayout &Layout) override {
     //XXX: Implement if necessary.
   }
-  void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
+  void RecordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
                         const MCFragment *Fragment, const MCFixup &Fixup,
                         MCValue Target, bool &IsPCRel,
                         uint64_t &FixedValue) override {

Modified: llvm/trunk/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp (original)
+++ llvm/trunk/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp Mon Jan 19 15:11:14 2015
@@ -777,19 +777,6 @@ public:
                                      MachO::CPU_TYPE_X86_64, Subtype);
   }
 
-  bool doesSectionRequireSymbols(const MCSection &Section) const override {
-    // Temporary labels in the string literals sections require symbols. The
-    // issue is that the x86_64 relocation format does not allow symbol +
-    // offset, and so the linker does not have enough information to resolve the
-    // access to the appropriate atom unless an external relocation is used. For
-    // non-cstring sections, we expect the compiler to use a non-temporary label
-    // for anything that could have an addend pointing outside the symbol.
-    //
-    // See <rdar://problem/4765733>.
-    const MCSectionMachO &SMO = static_cast<const MCSectionMachO&>(Section);
-    return SMO.getType() == MachO::S_CSTRING_LITERALS;
-  }
-
   /// \brief Generate the compact unwind encoding for the CFI instructions.
   uint32_t generateCompactUnwindEncoding(
                              ArrayRef<MCCFIInstruction> Instrs) const override {

Modified: llvm/trunk/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp (original)
+++ llvm/trunk/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp Mon Jan 19 15:11:14 2015
@@ -10,6 +10,7 @@
 #include "MCTargetDesc/X86MCTargetDesc.h"
 #include "MCTargetDesc/X86FixupKinds.h"
 #include "llvm/ADT/Twine.h"
+#include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCAsmLayout.h"
 #include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCContext.h"
@@ -47,23 +48,21 @@ class X86MachObjectWriter : public MCMac
                               const MCFixup &Fixup,
                               MCValue Target,
                               uint64_t &FixedValue);
-  void RecordX86_64Relocation(MachObjectWriter *Writer,
-                              const MCAssembler &Asm,
+  void RecordX86_64Relocation(MachObjectWriter *Writer, MCAssembler &Asm,
                               const MCAsmLayout &Layout,
-                              const MCFragment *Fragment,
-                              const MCFixup &Fixup,
-                              MCValue Target,
-                              uint64_t &FixedValue);
+                              const MCFragment *Fragment, const MCFixup &Fixup,
+                              MCValue Target, uint64_t &FixedValue);
+
 public:
   X86MachObjectWriter(bool Is64Bit, uint32_t CPUType,
                       uint32_t CPUSubtype)
     : MCMachObjectTargetWriter(Is64Bit, CPUType, CPUSubtype,
                                /*UseAggressiveSymbolFolding=*/Is64Bit) {}
 
-  void RecordRelocation(MachObjectWriter *Writer,
-                        const MCAssembler &Asm, const MCAsmLayout &Layout,
-                        const MCFragment *Fragment, const MCFixup &Fixup,
-                        MCValue Target, uint64_t &FixedValue) override {
+  void RecordRelocation(MachObjectWriter *Writer, MCAssembler &Asm,
+                        const MCAsmLayout &Layout, const MCFragment *Fragment,
+                        const MCFixup &Fixup, MCValue Target,
+                        uint64_t &FixedValue) override {
     if (Writer->is64Bit())
       RecordX86_64Relocation(Writer, Asm, Layout, Fragment, Fixup, Target,
                              FixedValue);
@@ -97,13 +96,10 @@ static unsigned getFixupKindLog2Size(uns
   }
 }
 
-void X86MachObjectWriter::RecordX86_64Relocation(MachObjectWriter *Writer,
-                                                 const MCAssembler &Asm,
-                                                 const MCAsmLayout &Layout,
-                                                 const MCFragment *Fragment,
-                                                 const MCFixup &Fixup,
-                                                 MCValue Target,
-                                                 uint64_t &FixedValue) {
+void X86MachObjectWriter::RecordX86_64Relocation(
+    MachObjectWriter *Writer, MCAssembler &Asm, const MCAsmLayout &Layout,
+    const MCFragment *Fragment, const MCFixup &Fixup, MCValue Target,
+    uint64_t &FixedValue) {
   unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, Fixup.getKind());
   unsigned IsRIPRel = isFixupKindRIPRel(Fixup.getKind());
   unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind());
@@ -117,6 +113,7 @@ void X86MachObjectWriter::RecordX86_64Re
   unsigned Index = 0;
   unsigned IsExtern = 0;
   unsigned Type = 0;
+  const MCSymbolData *RelSymbol = nullptr;
 
   Value = Target.getConstant();
 
@@ -132,7 +129,6 @@ void X86MachObjectWriter::RecordX86_64Re
   if (Target.isAbsolute()) { // constant
     // SymbolNum of 0 indicates the absolute section.
     Type = MachO::X86_64_RELOC_UNSIGNED;
-    Index = 0;
 
     // FIXME: I believe this is broken, I don't think the linker can understand
     // it. I think it would require a local relocation, but I'm not sure if that
@@ -193,36 +189,30 @@ void X86MachObjectWriter::RecordX86_64Re
     Value -= Writer->getSymbolAddress(&B_SD, Layout) -
       (!B_Base ? 0 : Writer->getSymbolAddress(B_Base, Layout));
 
-    if (A_Base) {
-      Index = A_Base->getIndex();
-      IsExtern = 1;
-    } else {
+    if (!A_Base)
       Index = A_SD.getFragment()->getParent()->getOrdinal() + 1;
-      IsExtern = 0;
-    }
     Type = MachO::X86_64_RELOC_UNSIGNED;
 
     MachO::any_relocation_info MRE;
     MRE.r_word0 = FixupOffset;
-    MRE.r_word1 = ((Index     <<  0) |
-                   (IsPCRel   << 24) |
-                   (Log2Size  << 25) |
-                   (IsExtern  << 27) |
-                   (Type      << 28));
-    Writer->addRelocation(Fragment->getParent(), MRE);
+    MRE.r_word1 =
+        (Index << 0) | (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
+    Writer->addRelocation(A_Base, Fragment->getParent(), MRE);
 
-    if (B_Base) {
-      Index = B_Base->getIndex();
-      IsExtern = 1;
-    } else {
+    if (B_Base)
+      RelSymbol = B_Base;
+    else
       Index = B_SD.getFragment()->getParent()->getOrdinal() + 1;
-      IsExtern = 0;
-    }
     Type = MachO::X86_64_RELOC_SUBTRACTOR;
   } else {
     const MCSymbol *Symbol = &Target.getSymA()->getSymbol();
+    if (Symbol->isTemporary() && Value) {
+      const MCSection &Sec = Symbol->getSection();
+      if (!Asm.getContext().getAsmInfo()->isSectionAtomizableBySymbols(Sec))
+        Asm.addLocalUsedInReloc(*Symbol);
+    }
     const MCSymbolData &SD = Asm.getSymbolData(*Symbol);
-    const MCSymbolData *Base = Asm.getAtom(&SD);
+    RelSymbol = Asm.getAtom(&SD);
 
     // Relocations inside debug sections always use local relocations when
     // possible. This seems to be done because the debugger doesn't fully
@@ -232,23 +222,20 @@ void X86MachObjectWriter::RecordX86_64Re
       const MCSectionMachO &Section = static_cast<const MCSectionMachO&>(
         Fragment->getParent()->getSection());
       if (Section.hasAttribute(MachO::S_ATTR_DEBUG))
-        Base = nullptr;
+        RelSymbol = nullptr;
     }
 
     // x86_64 almost always uses external relocations, except when there is no
     // symbol to use as a base address (a local symbol with no preceding
     // non-local symbol).
-    if (Base) {
-      Index = Base->getIndex();
-      IsExtern = 1;
-
+    if (RelSymbol) {
       // Add the local offset, if needed.
-      if (Base != &SD)
-        Value += Layout.getSymbolOffset(&SD) - Layout.getSymbolOffset(Base);
+      if (RelSymbol != &SD)
+        Value +=
+            Layout.getSymbolOffset(&SD) - Layout.getSymbolOffset(RelSymbol);
     } else if (Symbol->isInSection() && !Symbol->isVariable()) {
       // The index is the section ordinal (1-based).
       Index = SD.getFragment()->getParent()->getOrdinal() + 1;
-      IsExtern = 0;
       Value += Writer->getSymbolAddress(&SD, Layout);
 
       if (IsPCRel)
@@ -347,12 +334,9 @@ void X86MachObjectWriter::RecordX86_64Re
   // struct relocation_info (8 bytes)
   MachO::any_relocation_info MRE;
   MRE.r_word0 = FixupOffset;
-  MRE.r_word1 = ((Index     <<  0) |
-                 (IsPCRel   << 24) |
-                 (Log2Size  << 25) |
-                 (IsExtern  << 27) |
-                 (Type      << 28));
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  MRE.r_word1 = (Index << 0) | (IsPCRel << 24) | (Log2Size << 25) |
+                (IsExtern << 27) | (Type << 28);
+  Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
 }
 
 bool X86MachObjectWriter::RecordScatteredRelocation(MachObjectWriter *Writer,
@@ -424,7 +408,7 @@ bool X86MachObjectWriter::RecordScattere
                    (IsPCRel                   << 30) |
                    MachO::R_SCATTERED);
     MRE.r_word1 = Value2;
-    Writer->addRelocation(Fragment->getParent(), MRE);
+    Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
   } else {
     // If the offset is more than 24-bits, it won't fit in a scattered
     // relocation offset field, so we fall back to using a non-scattered
@@ -446,7 +430,7 @@ bool X86MachObjectWriter::RecordScattere
                  (IsPCRel     << 30) |
                  MachO::R_SCATTERED);
   MRE.r_word1 = Value;
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
   return true;
 }
 
@@ -467,7 +451,6 @@ void X86MachObjectWriter::RecordTLVPRelo
 
   // Get the symbol data.
   const MCSymbolData *SD_A = &Asm.getSymbolData(Target.getSymA()->getSymbol());
-  unsigned Index = SD_A->getIndex();
 
   // We're only going to have a second symbol in pic mode and it'll be a
   // subtraction from the picbase. For 32-bit pic the addend is the difference
@@ -490,12 +473,9 @@ void X86MachObjectWriter::RecordTLVPRelo
   // struct relocation_info (8 bytes)
   MachO::any_relocation_info MRE;
   MRE.r_word0 = Value;
-  MRE.r_word1 = ((Index                    <<  0) |
-                 (IsPCRel                  << 24) |
-                 (Log2Size                 << 25) |
-                 (1                        << 27) | // r_extern
-                 (MachO::GENERIC_RELOC_TLV << 28)); // r_type
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  MRE.r_word1 =
+      (IsPCRel << 24) | (Log2Size << 25) | (MachO::GENERIC_RELOC_TLV << 28);
+  Writer->addRelocation(SD_A, Fragment->getParent(), MRE);
 }
 
 void X86MachObjectWriter::RecordX86Relocation(MachObjectWriter *Writer,
@@ -546,8 +526,8 @@ void X86MachObjectWriter::RecordX86Reloc
   // See <reloc.h>.
   uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
   unsigned Index = 0;
-  unsigned IsExtern = 0;
   unsigned Type = 0;
+  const MCSymbolData *RelSymbol = nullptr;
 
   if (Target.isAbsolute()) { // constant
     // SymbolNum of 0 indicates the absolute section.
@@ -568,8 +548,7 @@ void X86MachObjectWriter::RecordX86Reloc
 
     // Check whether we need an external or internal relocation.
     if (Writer->doesSymbolRequireExternRelocation(SD)) {
-      IsExtern = 1;
-      Index = SD->getIndex();
+      RelSymbol = SD;
       // For external relocations, make sure to offset the fixup value to
       // compensate for the addend of the symbol address, if it was
       // undefined. This occurs with weak definitions, for example.
@@ -591,12 +570,9 @@ void X86MachObjectWriter::RecordX86Reloc
   // struct relocation_info (8 bytes)
   MachO::any_relocation_info MRE;
   MRE.r_word0 = FixupOffset;
-  MRE.r_word1 = ((Index     <<  0) |
-                 (IsPCRel   << 24) |
-                 (Log2Size  << 25) |
-                 (IsExtern  << 27) |
-                 (Type      << 28));
-  Writer->addRelocation(Fragment->getParent(), MRE);
+  MRE.r_word1 =
+      (Index << 0) | (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
+  Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
 }
 
 MCObjectWriter *llvm::createX86MachObjectWriter(raw_ostream &OS,

Added: llvm/trunk/test/MC/MachO/AArch64/mergeable.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/MachO/AArch64/mergeable.s?rev=226503&view=auto
==============================================================================
--- llvm/trunk/test/MC/MachO/AArch64/mergeable.s (added)
+++ llvm/trunk/test/MC/MachO/AArch64/mergeable.s Mon Jan 19 15:11:14 2015
@@ -0,0 +1,59 @@
+// RUN: llvm-mc -triple aarch64-apple-darwin14 %s -filetype=obj -o - | llvm-readobj -r --expand-relocs | FileCheck %s
+
+// Test that we "S + K" produce a relocation with a symbol, but just S produces
+// a relocation with the section.
+
+	.section	__TEXT,__literal4,4byte_literals
+L0:
+	.long	42
+
+	.section	__TEXT,__cstring,cstring_literals
+L1:
+	.asciz	"42"
+
+	.section	__DATA,__data
+	.quad	L0
+	.quad	L0 + 1
+	.quad	L1
+	.quad	L1 + 1
+
+// CHECK:      Relocations [
+// CHECK-NEXT:   Section __data {
+// CHECK-NEXT:     Relocation {
+// CHECK-NEXT:       Offset: 0x18
+// CHECK-NEXT:       PCRel: 0
+// CHECK-NEXT:       Length: 3
+// CHECK-NEXT:       Extern: 1
+// CHECK-NEXT:       Type: ARM64_RELOC_UNSIGNED (0)
+// CHECK-NEXT:       Symbol: L1
+// CHECK-NEXT:       Scattered: 0
+// CHECK-NEXT:     }
+// CHECK-NEXT:     Relocation {
+// CHECK-NEXT:       Offset: 0x10
+// CHECK-NEXT:       PCRel: 0
+// CHECK-NEXT:       Length: 3
+// CHECK-NEXT:       Extern: 1
+// CHECK-NEXT:       Type: ARM64_RELOC_UNSIGNED (0)
+// CHECK-NEXT:       Symbol: L1
+// CHECK-NEXT:       Scattered: 0
+// CHECK-NEXT:     }
+// CHECK-NEXT:     Relocation {
+// CHECK-NEXT:       Offset: 0x8
+// CHECK-NEXT:       PCRel: 0
+// CHECK-NEXT:       Length: 3
+// CHECK-NEXT:       Extern: 1
+// CHECK-NEXT:       Type: ARM64_RELOC_UNSIGNED (0)
+// CHECK-NEXT:       Symbol: L0
+// CHECK-NEXT:       Scattered: 0
+// CHECK-NEXT:     }
+// CHECK-NEXT:     Relocation {
+// CHECK-NEXT:       Offset: 0x0
+// CHECK-NEXT:       PCRel: 0
+// CHECK-NEXT:       Length: 3
+// CHECK-NEXT:       Extern: 0
+// CHECK-NEXT:       Type: ARM64_RELOC_UNSIGNED (0)
+// CHECK-NEXT:       Symbol: 0x2
+// CHECK-NEXT:       Scattered: 0
+// CHECK-NEXT:     }
+// CHECK-NEXT:   }
+// CHECK-NEXT: ]

Added: llvm/trunk/test/MC/MachO/x86_64-mergeable.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/MachO/x86_64-mergeable.s?rev=226503&view=auto
==============================================================================
--- llvm/trunk/test/MC/MachO/x86_64-mergeable.s (added)
+++ llvm/trunk/test/MC/MachO/x86_64-mergeable.s Mon Jan 19 15:11:14 2015
@@ -0,0 +1,59 @@
+// RUN: llvm-mc -triple x86_64-apple-darwin14 %s -filetype=obj -o - | llvm-readobj -r --expand-relocs | FileCheck %s
+
+// Test that we "S + K" produce a relocation with a symbol, but just S produces
+// a relocation with the section.
+
+	.section	__TEXT,__literal4,4byte_literals
+L0:
+	.long	42
+
+	.section	__TEXT,__cstring,cstring_literals
+L1:
+	.asciz	"42"
+
+	.section	__DATA,__data
+	.quad	L0
+	.quad	L0 + 1
+	.quad	L1
+	.quad	L1 + 1
+
+// CHECK:      Relocations [
+// CHECK-NEXT:   Section __data {
+// CHECK-NEXT:     Relocation {
+// CHECK-NEXT:       Offset: 0x18
+// CHECK-NEXT:       PCRel: 0
+// CHECK-NEXT:       Length: 3
+// CHECK-NEXT:       Extern: 1
+// CHECK-NEXT:       Type: X86_64_RELOC_UNSIGNED (0)
+// CHECK-NEXT:       Symbol: L1
+// CHECK-NEXT:       Scattered: 0
+// CHECK-NEXT:     }
+// CHECK-NEXT:     Relocation {
+// CHECK-NEXT:       Offset: 0x10
+// CHECK-NEXT:       PCRel: 0
+// CHECK-NEXT:       Length: 3
+// CHECK-NEXT:       Extern: 0
+// CHECK-NEXT:       Type: X86_64_RELOC_UNSIGNED (0)
+// CHECK-NEXT:       Symbol: 0x3
+// CHECK-NEXT:       Scattered: 0
+// CHECK-NEXT:     }
+// CHECK-NEXT:     Relocation {
+// CHECK-NEXT:       Offset: 0x8
+// CHECK-NEXT:       PCRel: 0
+// CHECK-NEXT:       Length: 3
+// CHECK-NEXT:       Extern: 1
+// CHECK-NEXT:       Type: X86_64_RELOC_UNSIGNED (0)
+// CHECK-NEXT:       Symbol: L0
+// CHECK-NEXT:       Scattered: 0
+// CHECK-NEXT:     }
+// CHECK-NEXT:     Relocation {
+// CHECK-NEXT:       Offset: 0x0
+// CHECK-NEXT:       PCRel: 0
+// CHECK-NEXT:       Length: 3
+// CHECK-NEXT:       Extern: 0
+// CHECK-NEXT:       Type: X86_64_RELOC_UNSIGNED (0)
+// CHECK-NEXT:       Symbol: 0x2
+// CHECK-NEXT:       Scattered: 0
+// CHECK-NEXT:     }
+// CHECK-NEXT:   }
+// CHECK-NEXT: ]

Modified: llvm/trunk/test/MC/MachO/x86_64-symbols.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/MachO/x86_64-symbols.s?rev=226503&r1=226502&r2=226503&view=diff
==============================================================================
--- llvm/trunk/test/MC/MachO/x86_64-symbols.s (original)
+++ llvm/trunk/test/MC/MachO/x86_64-symbols.s Mon Jan 19 15:11:14 2015
@@ -121,6 +121,12 @@ D38:
 //L39:
 //D39:
 
+        .section foo, bar
+        .long L4 + 1
+        .long L35 + 1
+        .long L36 + 1
+        .long L37 + 1
+        .long L38 + 1
 
 // CHECK: Symbols [
 // CHECK-NEXT:   Symbol {





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