diff --git a/include/llvm/MC/MCSection.h b/include/llvm/MC/MCSection.h
index 4d50502..8216b68 100644
--- a/include/llvm/MC/MCSection.h
+++ b/include/llvm/MC/MCSection.h
@@ -67,25 +67,154 @@
                                       raw_ostream &OS) const;
   };
 
+  
+  /// MCSectionMachO - This represents a section on a Mach-O system (used by
+  /// Mac OS X).  On a Mac system, these are also described in
+  /// /usr/include/mach-o/loader.h.
   class MCSectionMachO : public MCSection {
-    std::string Name;
+    char SegmentName[16];  // Not necessarily null terminated!
+    char SectionName[16];  // Not necessarily null terminated!
     
-    /// IsDirective - This is true if the section name is a directive, not
-    /// something that should be printed with ".section".
-    ///
-    /// FIXME: This is a hack.  Switch to a semantic view of the section instead
-    /// of a syntactic one.
-    bool IsDirective;
+    /// TypeAndAttributes - This is the SECTION_TYPE and SECTION_ATTRIBUTES
+    /// field of a section, drawn from the enums below.
+    unsigned TypeAndAttributes;
     
-    MCSectionMachO(const StringRef &Name, bool IsDirective, SectionKind K,
-                   MCContext &Ctx);
+    /// Reserved2 - The 'reserved2' field of a section, used to represent the
+    /// size of stubs, for example.
+    unsigned Reserved2;
+    
+    MCSectionMachO(const StringRef &Segment, const StringRef &Section,
+                   unsigned TAA, unsigned reserved2, SectionKind K)
+      : MCSection(K), TypeAndAttributes(TAA), Reserved2(reserved2) {
+      assert(Segment.size() <= 16 && Section.size() <= 16 &&
+             "Segment or section string too long");
+      for (unsigned i = 0; i != 16; ++i) {
+        if (i < Segment.size())
+          SegmentName[i] = Segment[i];
+        else
+          SegmentName[i] = 0;
+        
+        if (i < Section.size())
+          SectionName[i] = Section[i];
+        else
+          SectionName[i] = 0;
+      }        
+    }
   public:
     
-    static MCSectionMachO *Create(const StringRef &Name, bool IsDirective, 
+    static MCSectionMachO *Create(const StringRef &Segment,
+                                  const StringRef &Section,
+                                  unsigned TypeAndAttributes,
+                                  unsigned Reserved2,
                                   SectionKind K, MCContext &Ctx);
+    
+    /// These are the section type and attributes fields.  A MachO section can
+    /// have only one Type, but can have any of the attributes specified.
+    enum {
+      // TypeAndAttributes bitmasks.
+      SECTION_TYPE       = 0x000000FFU,
+      SECTION_ATTRIBUTES = 0xFFFFFF00U,
+      
+      // Valid section types.
+      
+      /// S_REGULAR - Regular section.
+      S_REGULAR                    = 0x00U,
+      /// S_ZEROFILL - Zero fill on demand section.
+      S_ZEROFILL                   = 0x01U,
+      /// S_CSTRING_LITERALS - Section with literal C strings.
+      S_CSTRING_LITERALS           = 0x02U,
+      /// S_4BYTE_LITERALS - Section with 4 byte literals.
+      S_4BYTE_LITERALS             = 0x03U,
+      /// S_8BYTE_LITERALS - Section with 8 byte literals.
+      S_8BYTE_LITERALS             = 0x04U,
+      /// S_LITERAL_POINTERS - Section with pointers to literals.
+      S_LITERAL_POINTERS           = 0x05U,
+      /// S_NON_LAZY_SYMBOL_POINTERS - Section with non-lazy symbol pointers.
+      S_NON_LAZY_SYMBOL_POINTERS   = 0x06U,
+      /// S_LAZY_SYMBOL_POINTERS - Section with lazy symbol pointers.
+      S_LAZY_SYMBOL_POINTERS       = 0x07U,
+      /// S_SYMBOL_STUBS - Section with symbol stubs, byte size of stub in
+      /// the Reserved2 field.
+      S_SYMBOL_STUBS               = 0x08U,
+      /// S_SYMBOL_STUBS - Section with only function pointers for
+      /// initialization.
+      S_MOD_INIT_FUNC_POINTERS     = 0x09U,
+      /// S_MOD_INIT_FUNC_POINTERS - Section with only function pointers for
+      /// termination.
+      S_MOD_TERM_FUNC_POINTERS     = 0x0AU,
+      /// S_COALESCED - Section contains symbols that are to be coalesced.
+      S_COALESCED                  = 0x0BU,
+      /// S_GB_ZEROFILL - Zero fill on demand section (that can be larger than 4
+      /// gigabytes).
+      S_GB_ZEROFILL                = 0x0CU,
+      /// S_INTERPOSING - Section with only pairs of function pointers for
+      /// interposing.
+      S_INTERPOSING                = 0x0DU,
+      /// S_16BYTE_LITERALS - Section with only 16 byte literals.
+      S_16BYTE_LITERALS            = 0x0EU,
+      /// S_DTRACE_DOF - Section contains DTrace Object Format.
+      S_DTRACE_DOF                 = 0x0FU,
+      /// S_LAZY_DYLIB_SYMBOL_POINTERS - Section with lazy symbol pointers to
+      /// lazy loaded dylibs.
+      S_LAZY_DYLIB_SYMBOL_POINTERS = 0x10U,
 
-    const std::string &getName() const { return Name; }
-    bool isDirective() const { return IsDirective; }
+      LAST_KNOWN_SECTION_TYPE = S_LAZY_DYLIB_SYMBOL_POINTERS,
+      
+
+      // Valid section attributes.
+      
+      /// S_ATTR_PURE_INSTRUCTIONS - Section contains only true machine
+      /// instructions.
+      S_ATTR_PURE_INSTRUCTIONS   = 1U << 31,
+      /// S_ATTR_NO_TOC - Section contains coalesced symbols that are not to be
+      /// in a ranlib table of contents.
+      S_ATTR_NO_TOC              = 1U << 30,
+      /// S_ATTR_STRIP_STATIC_SYMS - Ok to strip static symbols in this section
+      /// in files with the MY_DYLDLINK flag.
+      S_ATTR_STRIP_STATIC_SYMS   = 1U << 29,
+      /// S_ATTR_NO_DEAD_STRIP - No dead stripping.
+      S_ATTR_NO_DEAD_STRIP       = 1U << 28,
+      /// S_ATTR_LIVE_SUPPORT - Blocks are live if they reference live blocks.
+      S_ATTR_LIVE_SUPPORT        = 1U << 27,
+      /// S_ATTR_SELF_MODIFYING_CODE - Used with i386 code stubs written on by
+      /// dyld.
+      S_ATTR_SELF_MODIFYING_CODE = 1U << 26,
+      /// S_ATTR_DEBUG - A debug section.
+      S_ATTR_DEBUG               = 1U << 25,
+      /// S_ATTR_SOME_INSTRUCTIONS - Section contains some machine instructions.
+      S_ATTR_SOME_INSTRUCTIONS   = 1U << 10,
+      /// S_ATTR_EXT_RELOC - Section has external relocation entries.
+      S_ATTR_EXT_RELOC           = 1U << 9,
+      /// S_ATTR_LOC_RELOC - Section has local relocation entries.
+      S_ATTR_LOC_RELOC           = 1U << 8
+    };
+
+    StringRef getSegmentName() const {
+      // SegmentName is not necessarily null terminated!
+      if (SegmentName[15])
+        return StringRef(SegmentName, 16);
+      return StringRef(SegmentName);
+    }
+    StringRef getSectionName() const {
+      // SectionName is not necessarily null terminated!
+      if (SectionName[15])
+        return StringRef(SectionName, 16);
+      return StringRef(SectionName);
+    }
+    
+    unsigned getTypeAndAttributes() const { return TypeAndAttributes; }
+    
+    
+    /// ParseSectionSpecifier - Parse the section specifier indicated by "Spec".
+    /// This is a string that can appear after a .section directive in a mach-o
+    /// flavored .s file.  If successful, this fills in the specified Out
+    /// parameters and returns an empty string.  When an invalid section
+    /// specifier is present, this returns a string indicating the problem.
+    static std::string ParseSectionSpecifier(StringRef Spec,       // In.
+                                             StringRef &Segment,   // Out.
+                                             StringRef &Section,   // Out.
+                                             unsigned  &TAA,       // Out.
+                                             unsigned  &StubSize); // Out.
     
     virtual void PrintSwitchToSection(const TargetAsmInfo &TAI,
                                       raw_ostream &OS) const;
diff --git a/include/llvm/Target/TargetLoweringObjectFile.h b/include/llvm/Target/TargetLoweringObjectFile.h
index 0b6fd30..2ca1963 100644
--- a/include/llvm/Target/TargetLoweringObjectFile.h
+++ b/include/llvm/Target/TargetLoweringObjectFile.h
@@ -257,9 +257,30 @@
                                           Mangler *) const;
 
   /// getMachOSection - Return the MCSection for the specified mach-o section.
-  /// FIXME: Switch this to a semantic view eventually.
-  const MCSection *getMachOSection(const char *Name, bool isDirective,
-                                   SectionKind K) const;
+  /// This requires the operands to be valid.
+  const MCSection *getMachOSection(StringRef Segment, StringRef Section,
+                                   unsigned TypeAndAttributes,
+                                   SectionKind K) const {
+    return getMachOSection(Segment, Section, TypeAndAttributes, 0, K);
+  }
+  const MCSection *getMachOSection(StringRef Segment, StringRef Section,
+                                   unsigned TypeAndAttributes,
+                                   unsigned Reserved2, SectionKind K) const;
+
+  /// getTextCoalSection - Return the "__TEXT,__textcoal_nt" section we put weak
+  /// symbols into.
+  const MCSection *getTextCoalSection() const {
+    return TextCoalSection;
+  }
+  
+  /// getLazySymbolPointerSection - Return the section corresponding to
+  /// the .lazy_symbol_pointer directive.
+  const MCSection *getLazySymbolPointerSection() const;
+  
+  /// getNonLazySymbolPointerSection - Return the section corresponding to
+  /// the .non_lazy_symbol_pointer directive.
+  const MCSection *getNonLazySymbolPointerSection() const;
+  
 };
 
 
diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index 0aed948..7dcca7b 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -222,7 +222,9 @@
   OS << ".zerofill ";
   
   // This is a mach-o specific directive.
-  OS << '"' << ((MCSectionMachO*)Section)->getName() << '"';
+  const MCSectionMachO *MOSection = ((const MCSectionMachO*)Section);
+  OS << '"' << MOSection->getSegmentName() << ","
+     << MOSection->getSectionName() << '"';
   
   
   if (Symbol != NULL) {
diff --git a/lib/MC/MCSection.cpp b/lib/MC/MCSection.cpp
index 65e86d3..291e40d 100644
--- a/lib/MC/MCSection.cpp
+++ b/lib/MC/MCSection.cpp
@@ -115,25 +115,272 @@
 // MCSectionMachO
 //===----------------------------------------------------------------------===//
 
-MCSectionMachO *MCSectionMachO::
-Create(const StringRef &Name, bool IsDirective, SectionKind K, MCContext &Ctx) {
-  return new (Ctx) MCSectionMachO(Name, IsDirective, K, Ctx);
-}
+/// SectionTypeDescriptors - These are strings that describe the various section
+/// types.  This *must* be kept in order with and stay synchronized with the
+/// section type list.
+static const struct {
+  const char *AssemblerName, *EnumName;
+} SectionTypeDescriptors[MCSectionMachO::LAST_KNOWN_SECTION_TYPE+1] = {
+  { "regular",                  "S_REGULAR" },                    // 0x00
+  { 0,                          "S_ZEROFILL" },                   // 0x01
+  { "cstring_literals",         "S_CSTRING_LITERALS" },           // 0x02
+  { "4byte_literals",           "S_4BYTE_LITERALS" },             // 0x03
+  { "8byte_literals",           "S_8BYTE_LITERALS" },             // 0x04
+  { "literal_pointers",         "S_LITERAL_POINTERS" },           // 0x05
+  { "non_lazy_symbol_pointers", "S_NON_LAZY_SYMBOL_POINTERS" },   // 0x06
+  { "lazy_symbol_pointers",     "S_LAZY_SYMBOL_POINTERS" },       // 0x07
+  { "symbol_stubs",             "S_SYMBOL_STUBS" },               // 0x08
+  { "mod_init_funcs",           "S_MOD_INIT_FUNC_POINTERS" },     // 0x09
+  { "mod_term_funcs",           "S_MOD_TERM_FUNC_POINTERS" },     // 0x0A
+  { "coalesced",                "S_COALESCED" },                  // 0x0B
+  { 0, /*FIXME??*/              "S_GB_ZEROFILL" },                // 0x0C
+  { "interposing",              "S_INTERPOSING" },                // 0x0D
+  { "16byte_literals",          "S_16BYTE_LITERALS" },            // 0x0E
+  { 0, /*FIXME??*/              "S_DTRACE_DOF" },                 // 0x0F
+  { 0, /*FIXME??*/              "S_LAZY_DYLIB_SYMBOL_POINTERS" }  // 0x10
+};
 
-MCSectionMachO::MCSectionMachO(const StringRef &name, bool isDirective,
-                               SectionKind K, MCContext &Ctx)
-  : MCSection(K), Name(name), IsDirective(isDirective) {
-  Ctx.SetSection(Name, this);
+
+/// SectionAttrDescriptors - This is an array of descriptors for section
+/// attributes.  Unlike the SectionTypeDescriptors, this is not directly indexed
+/// by attribute, instead it is searched.  The last entry has a zero AttrFlag
+/// value.
+static const struct {
+  unsigned AttrFlag;
+  const char *AssemblerName, *EnumName;
+} SectionAttrDescriptors[] = {
+#define ENTRY(ASMNAME, ENUM) \
+  { MCSectionMachO::ENUM, ASMNAME, #ENUM },
+ENTRY("pure_instructions",   S_ATTR_PURE_INSTRUCTIONS)
+ENTRY("no_toc",              S_ATTR_NO_TOC)
+ENTRY("strip_static_syms",   S_ATTR_STRIP_STATIC_SYMS)
+ENTRY("no_dead_strip",       S_ATTR_NO_DEAD_STRIP)
+ENTRY("live_support",        S_ATTR_LIVE_SUPPORT)
+ENTRY("self_modifying_code", S_ATTR_SELF_MODIFYING_CODE)
+ENTRY("debug",               S_ATTR_DEBUG)
+ENTRY(0 /*FIXME*/,           S_ATTR_SOME_INSTRUCTIONS)
+ENTRY(0 /*FIXME*/,           S_ATTR_EXT_RELOC)
+ENTRY(0 /*FIXME*/,           S_ATTR_LOC_RELOC)
+#undef ENTRY
+  { 0, "none", 0 }
+};
+
+
+MCSectionMachO *MCSectionMachO::
+Create(const StringRef &Segment, const StringRef &Section,
+       unsigned TypeAndAttributes, unsigned Reserved2,
+       SectionKind K, MCContext &Ctx) {
+  // S_SYMBOL_STUBS must be set for Reserved2 to be non-zero.
+  return new (Ctx) MCSectionMachO(Segment, Section, TypeAndAttributes,
+                                  Reserved2, K);
 }
 
 void MCSectionMachO::PrintSwitchToSection(const TargetAsmInfo &TAI,
                                           raw_ostream &OS) const {
-  if (!isDirective())
-    OS << "\t.section\t" << getName() << '\n';
+  OS << "\t.section\t" << getSegmentName() << ',' << getSectionName();
+  
+  // Get the section type and attributes.
+  unsigned TAA = getTypeAndAttributes();
+  if (TAA == 0) {
+    OS << '\n';
+    return;
+  }
+
+  OS << ',';
+  
+  unsigned SectionType = TAA & MCSectionMachO::SECTION_TYPE;
+  assert(SectionType <= MCSectionMachO::LAST_KNOWN_SECTION_TYPE &&
+         "Invalid SectionType specified!");
+
+  if (SectionTypeDescriptors[SectionType].AssemblerName)
+    OS << SectionTypeDescriptors[SectionType].AssemblerName;
   else
-    OS << getName() << '\n';
+    OS << "<<" << SectionTypeDescriptors[SectionType].EnumName << ">>";
+  
+  // If we don't have any attributes, we're done.
+  unsigned SectionAttrs = TAA & MCSectionMachO::SECTION_ATTRIBUTES;
+  if (SectionAttrs == 0) {
+    // If we have a S_SYMBOL_STUBS size specified, print it along with 'none' as
+    // the attribute specifier.
+    if (Reserved2 != 0)
+      OS << ",none," << Reserved2;
+    OS << '\n';
+    return;
+  }
+
+  // Check each attribute to see if we have it.
+  char Separator = ',';
+  for (unsigned i = 0; SectionAttrDescriptors[i].AttrFlag; ++i) {
+    // Check to see if we have this attribute.
+    if ((SectionAttrDescriptors[i].AttrFlag & SectionAttrs) == 0)
+      continue;
+    
+    // Yep, clear it and print it.
+    SectionAttrs &= ~SectionAttrDescriptors[i].AttrFlag;
+    
+    OS << Separator;
+    if (SectionAttrDescriptors[i].AssemblerName)
+      OS << SectionAttrDescriptors[i].AssemblerName;
+    else
+      OS << "<<" << SectionAttrDescriptors[i].EnumName << ">>";
+    Separator = '+';
+  }
+  
+  assert(SectionAttrs == 0 && "Unknown section attributes!");
+  
+  // If we have a S_SYMBOL_STUBS size specified, print it.
+  if (Reserved2 != 0)
+    OS << ',' << Reserved2;
+  OS << '\n';
 }
 
+/// StripSpaces - This removes leading and trailing spaces from the StringRef.
+static void StripSpaces(StringRef &Str) {
+  while (!Str.empty() && isspace(Str[0]))
+    Str = Str.substr(1);
+  while (!Str.empty() && isspace(Str.back()))
+    Str = Str.substr(0, Str.size()-1);
+}
+
+/// ParseSectionSpecifier - Parse the section specifier indicated by "Spec".
+/// This is a string that can appear after a .section directive in a mach-o
+/// flavored .s file.  If successful, this fills in the specified Out
+/// parameters and returns an empty string.  When an invalid section
+/// specifier is present, this returns a string indicating the problem.
+std::string MCSectionMachO::ParseSectionSpecifier(StringRef Spec,        // In.
+                                                  StringRef &Segment,    // Out.
+                                                  StringRef &Section,    // Out.
+                                                  unsigned  &TAA,        // Out.
+                                                  unsigned  &StubSize) { // Out.
+  // Find the first comma.
+  std::pair<StringRef, StringRef> Comma = Spec.split(',');
+  
+  // If there is no comma, we fail.
+  if (Comma.second.empty())
+    return "mach-o section specifier requires a segment and section "
+           "separated by a comma";
+  
+  // Capture segment, remove leading and trailing whitespace.
+  Segment = Comma.first;
+  StripSpaces(Segment);
+
+  // Verify that the segment is present and not too long.
+  if (Segment.empty() || Segment.size() > 16)
+    return "mach-o section specifier requires a segment whose length is "
+           "between 1 and 16 characters";
+  
+  // Split the section name off from any attributes if present.
+  Comma = Comma.second.split(',');
+
+  // Capture section, remove leading and trailing whitespace.
+  Section = Comma.first;
+  StripSpaces(Section);
+  
+  // Verify that the section is present and not too long.
+  if (Section.empty() || Section.size() > 16)
+    return "mach-o section specifier requires a section whose length is "
+           "between 1 and 16 characters";
+
+  // If there is no comma after the section, we're done.
+  TAA = 0;
+  StubSize = 0;
+  if (Comma.second.empty())
+    return "";
+  
+  // Otherwise, we need to parse the section type and attributes.
+  Comma = Comma.second.split(',');
+  
+  // Get the section type.
+  StringRef SectionType = Comma.first;
+  StripSpaces(SectionType);
+  
+  // Figure out which section type it is.
+  unsigned TypeID;
+  for (TypeID = 0; TypeID !=MCSectionMachO::LAST_KNOWN_SECTION_TYPE+1; ++TypeID)
+    if (SectionTypeDescriptors[TypeID].AssemblerName &&
+        SectionType == SectionTypeDescriptors[TypeID].AssemblerName)
+      break;
+  
+  // If we didn't find the section type, reject it.
+  if (TypeID > MCSectionMachO::LAST_KNOWN_SECTION_TYPE)
+    return "mach-o section specifier uses an unknown section type";
+  
+  // Remember the TypeID.
+  TAA = TypeID;
+
+  // If we have no comma after the section type, there are no attributes.
+  if (Comma.second.empty()) {
+    // S_SYMBOL_STUBS always require a symbol stub size specifier.
+    if (TAA == MCSectionMachO::S_SYMBOL_STUBS)
+      return "mach-o section specifier of type 'symbol_stubs' requires a size "
+             "specifier";
+    return "";
+  }
+
+  // Otherwise, we do have some attributes.  Split off the size specifier if
+  // present.
+  Comma = Comma.second.split(',');
+  StringRef Attrs = Comma.first;
+  
+  // The attribute list is a '+' separated list of attributes.
+  std::pair<StringRef, StringRef> Plus = Attrs.split('+');
+  
+  while (1) {
+    StringRef Attr = Plus.first;
+    StripSpaces(Attr);
+
+    // Look up the attribute.
+    for (unsigned i = 0; ; ++i) {
+      if (SectionAttrDescriptors[i].AttrFlag == 0)
+        return "mach-o section specifier has invalid attribute";
+      
+      if (SectionAttrDescriptors[i].AssemblerName &&
+          Attr == SectionAttrDescriptors[i].AssemblerName) {
+        TAA |= SectionAttrDescriptors[i].AttrFlag;
+        break;
+      }
+    }
+    
+    if (Plus.second.empty()) break;
+    Plus = Plus.second.split('+');
+  };
+
+  // Okay, we've parsed the section attributes, see if we have a stub size spec.
+  if (Comma.second.empty()) {
+    // S_SYMBOL_STUBS always require a symbol stub size specifier.
+    if (TAA == MCSectionMachO::S_SYMBOL_STUBS)
+      return "mach-o section specifier of type 'symbol_stubs' requires a size "
+      "specifier";
+    return "";
+  }
+
+  // If we have a stub size spec, we must have a sectiontype of S_SYMBOL_STUBS.
+  if ((TAA & MCSectionMachO::SECTION_TYPE) != MCSectionMachO::S_SYMBOL_STUBS)
+    return "mach-o section specifier cannot have a stub size specified because "
+           "it does not have type 'symbol_stubs'";
+  
+  // Okay, if we do, it must be a number.
+  StringRef StubSizeStr = Comma.second;
+  StripSpaces(StubSizeStr);
+  
+  // Convert the a null terminated buffer for strtoul.
+  char TmpBuffer[32];
+  if (StubSizeStr.size() >= 32)
+    return"mach-o section specifier has a stub size specifier that is too long";
+  
+  memcpy(TmpBuffer, StubSizeStr.data(), StubSizeStr.size());
+  TmpBuffer[StubSizeStr.size()] = 0;
+  
+  char *EndPtr;
+  StubSize = strtoul(TmpBuffer, &EndPtr, 0);
+
+  if (EndPtr[0] != 0)
+    return "mach-o section specifier has a malformed stub size";
+  
+  return "";
+}
+
+
 //===----------------------------------------------------------------------===//
 // MCSectionCOFF
 //===----------------------------------------------------------------------===//
diff --git a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
index ca61d55..9f79938 100644
--- a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
+++ b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
@@ -1286,19 +1286,21 @@
     O << '\n';
     
     if (!FnStubs.empty()) {
-      const MCSection *StubSection;
-      if (TM.getRelocationModel() == Reloc::PIC_)
-        StubSection = TLOFMacho.getMachOSection(".section __TEXT,__picsymbolstu"
-                                                "b4,symbol_stubs,none,16", true,
-                                                SectionKind::getText());
-      else
-        StubSection = TLOFMacho.getMachOSection(".section __TEXT,__symbol_stub4"
-                                                ",symbol_stubs,none,12", true,
-                                                SectionKind::getText());
+      unsigned StubSize = 12;
+      const char *StubSectionName = "__symbol_stub4";
+      
+      if (TM.getRelocationModel() == Reloc::PIC_) {
+        StubSize = 16;
+        StubSectionName = "__picsymbolstub4";
+      }
+      
+      const MCSection *StubSection
+        = TLOFMacho.getMachOSection("__TEXT", StubSectionName,
+                                    MCSectionMachO::S_SYMBOL_STUBS,
+                                    StubSize, SectionKind::getText());
 
       const MCSection *LazySymbolPointerSection
-        = TLOFMacho.getMachOSection(".lazy_symbol_pointer", true,
-                                    SectionKind::getMetadata());
+        = TLOFMacho.getLazySymbolPointerSection();
     
       // Output stubs for dynamically-linked functions
       for (StringMap<FnStubInfo>::iterator I = FnStubs.begin(),
@@ -1333,9 +1335,8 @@
     
     // Output non-lazy-pointers for external and common global variables.
     if (!GVNonLazyPtrs.empty()) {
-      SwitchToSection(TLOFMacho.getMachOSection(".non_lazy_symbol_pointer",
-                                                true,
-                                                SectionKind::getMetadata()));
+      // Switch with ".non_lazy_symbol_pointer" directive.
+      SwitchToSection(TLOFMacho.getNonLazySymbolPointerSection());
       for (StringMap<std::string>::iterator I = GVNonLazyPtrs.begin(),
            E = GVNonLazyPtrs.end(); I != E; ++I) {
         O << I->second << ":\n";
diff --git a/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp b/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
index 9884ca3..73c9c03 100644
--- a/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
+++ b/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
@@ -846,22 +846,19 @@
 
   // Prime text sections so they are adjacent.  This reduces the likelihood a
   // large data or debug section causes a branch to exceed 16M limit.
-  
   TargetLoweringObjectFileMachO &TLOFMacho = 
     static_cast<TargetLoweringObjectFileMachO &>(getObjFileLowering());
-  SwitchToSection(TLOFMacho.getMachOSection("\t.section __TEXT,__textcoal_nt,"
-                                            "coalesced,pure_instructions", true,
-                                            SectionKind::getText()));
+  SwitchToSection(TLOFMacho.getTextCoalSection());
   if (TM.getRelocationModel() == Reloc::PIC_) {
-    SwitchToSection(TLOFMacho.getMachOSection("\t.section __TEXT,__picsymbolstu"
-                                              "b1,symbol_stubs,"
-                                              "pure_instructions,32", true,
-                                              SectionKind::getText()));
+    SwitchToSection(TLOFMacho.getMachOSection("__TEXT", "__picsymbolstub1",
+                                              MCSectionMachO::S_SYMBOL_STUBS |
+                                       MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+                                              32, SectionKind::getText()));
   } else if (TM.getRelocationModel() == Reloc::DynamicNoPIC) {
-    SwitchToSection(TLOFMacho.getMachOSection("\t.section __TEXT,__symbol_stub1"
-                                              ",symbol_stubs,"
-                                              "pure_instructions,16", true,
-                                              SectionKind::getText()));
+    SwitchToSection(TLOFMacho.getMachOSection("__TEXT","__symbol_stub1",
+                                              MCSectionMachO::S_SYMBOL_STUBS |
+                                       MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+                                              16, SectionKind::getText()));
   }
   SwitchToSection(getObjFileLowering().getTextSection());
 
@@ -985,17 +982,20 @@
   TargetLoweringObjectFileMachO &TLOFMacho = 
     static_cast<TargetLoweringObjectFileMachO &>(getObjFileLowering());
 
+  
+  const MCSection *LSPSection = 0;
+  if (!FnStubs.empty()) // .lazy_symbol_pointer
+    LSPSection = TLOFMacho.getLazySymbolPointerSection();
+    
+  
   // Output stubs for dynamically-linked functions
   if (TM.getRelocationModel() == Reloc::PIC_ && !FnStubs.empty()) {
     const MCSection *StubSection = 
-      TLOFMacho.getMachOSection("\t.section __TEXT,__picsymbolstub1,"
-                                "symbol_stubs,pure_instructions,32", true,
-                                SectionKind::getText());
-    const MCSection *LSPSection = 
-      TLOFMacho.getMachOSection(".lazy_symbol_pointer", true,
-                                SectionKind::getMetadata());
-    
-    for (StringMap<FnStubInfo>::iterator I = FnStubs.begin(), E = FnStubs.end();
+      TLOFMacho.getMachOSection("__TEXT", "__picsymbolstub1",
+                                MCSectionMachO::S_SYMBOL_STUBS |
+                                MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+                                32, SectionKind::getText());
+     for (StringMap<FnStubInfo>::iterator I = FnStubs.begin(), E = FnStubs.end();
          I != E; ++I) {
       SwitchToSection(StubSection);
       EmitAlignment(4);
@@ -1020,13 +1020,11 @@
       O << (isPPC64 ? "\t.quad" : "\t.long") << " dyld_stub_binding_helper\n";
     }
   } else if (!FnStubs.empty()) {
-    const MCSection *StubSection = 
-      TLOFMacho.getMachOSection("\t.section __TEXT,__symbol_stub1,symbol_stubs,"
-                                "pure_instructions,16", true,
-                                SectionKind::getText());
-    const MCSection *LSPSection = 
-      TLOFMacho.getMachOSection(".lazy_symbol_pointer", true,
-                                SectionKind::getMetadata());
+    const MCSection *StubSection =
+      TLOFMacho.getMachOSection("__TEXT","__symbol_stub1",
+                                MCSectionMachO::S_SYMBOL_STUBS |
+                                MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+                                16, SectionKind::getText());
     
     for (StringMap<FnStubInfo>::iterator I = FnStubs.begin(), E = FnStubs.end();
          I != E; ++I) {
@@ -1063,10 +1061,8 @@
 
   // Output macho stubs for external and common global variables.
   if (!GVStubs.empty()) {
-    const MCSection *TheSection = 
-      TLOFMacho.getMachOSection(".non_lazy_symbol_pointer", true,
-                                SectionKind::getMetadata());
-    SwitchToSection(TheSection);
+    // Switch with ".non_lazy_symbol_pointer" directive.
+    SwitchToSection(TLOFMacho.getNonLazySymbolPointerSection());
     for (StringMap<std::string>::iterator I = GVStubs.begin(),
          E = GVStubs.end(); I != E; ++I) {
       O << I->second << ":\n";
diff --git a/lib/Target/TargetLoweringObjectFile.cpp b/lib/Target/TargetLoweringObjectFile.cpp
index e41e7a9..2cde7d9 100644
--- a/lib/Target/TargetLoweringObjectFile.cpp
+++ b/lib/Target/TargetLoweringObjectFile.cpp
@@ -510,118 +510,176 @@
 
 
 const MCSection *TargetLoweringObjectFileMachO::
-getMachOSection(const char *Name, bool isDirective, SectionKind Kind) const {
-  if (MCSection *S = getContext().GetSection(Name))
-    return S;
-  return MCSectionMachO::Create(Name, isDirective, Kind, getContext());
+getMachOSection(StringRef Segment, StringRef Section,
+                unsigned TypeAndAttributes,
+                unsigned Reserved2, SectionKind Kind) const {
+  // FIXME: UNIQUE HERE.
+  //if (MCSection *S = getContext().GetSection(Name))
+  //  return S;
+  
+  return MCSectionMachO::Create(Segment, Section, TypeAndAttributes, Reserved2,
+                                Kind, getContext());
 }
 
 
-
 void TargetLoweringObjectFileMachO::Initialize(MCContext &Ctx,
                                                const TargetMachine &TM) {
   TargetLoweringObjectFile::Initialize(Ctx, TM);
-  TextSection = getMachOSection("\t.text", true, SectionKind::getText());
-  DataSection = getMachOSection("\t.data", true, SectionKind::getDataRel());
   
-  CStringSection = getMachOSection("\t.cstring", true,
-                                   SectionKind::getMergeable1ByteCString());
-  UStringSection = getMachOSection("__TEXT,__ustring", false,
-                                   SectionKind::getMergeable2ByteCString());
-  FourByteConstantSection = getMachOSection("\t.literal4\n", true,
-                                            SectionKind::getMergeableConst4());
-  EightByteConstantSection = getMachOSection("\t.literal8\n", true,
-                                             SectionKind::getMergeableConst8());
+  TextSection // .text
+    = getMachOSection("__TEXT", "__text",
+                      MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+                      SectionKind::getText());
+  DataSection // .data
+    = getMachOSection("__DATA", "__data", 0, SectionKind::getDataRel());
+  
+  CStringSection // .cstring
+    = getMachOSection("__TEXT", "__cstring", MCSectionMachO::S_CSTRING_LITERALS,
+                      SectionKind::getMergeable1ByteCString());
+  UStringSection
+    = getMachOSection("__TEXT","__ustring", 0,
+                      SectionKind::getMergeable2ByteCString());
+  FourByteConstantSection // .literal4
+    = getMachOSection("__TEXT", "__literal4", MCSectionMachO::S_4BYTE_LITERALS,
+                      SectionKind::getMergeableConst4());
+  EightByteConstantSection // .literal8
+    = getMachOSection("__TEXT", "__literal8", MCSectionMachO::S_8BYTE_LITERALS,
+                      SectionKind::getMergeableConst8());
   
   // ld_classic doesn't support .literal16 in 32-bit mode, and ld64 falls back
   // to using it in -static mode.
+  SixteenByteConstantSection = 0;
   if (TM.getRelocationModel() != Reloc::Static &&
       TM.getTargetData()->getPointerSize() == 32)
-    SixteenByteConstantSection = 
-      getMachOSection("\t.literal16\n", true, 
+    SixteenByteConstantSection =   // .literal16
+      getMachOSection("__TEXT", "__literal16",MCSectionMachO::S_16BYTE_LITERALS,
                       SectionKind::getMergeableConst16());
-  else
-    SixteenByteConstantSection = 0;
   
-  ReadOnlySection = getMachOSection("\t.const", true,
-                                    SectionKind::getReadOnly());
+  ReadOnlySection  // .const
+    = getMachOSection("__TEXT", "__const", 0, SectionKind::getReadOnly());
   
-  TextCoalSection =
-    getMachOSection("\t__TEXT,__textcoal_nt,coalesced,pure_instructions",
-                    false, SectionKind::getText());
-  ConstTextCoalSection = getMachOSection("\t__TEXT,__const_coal,coalesced",
-                                         false, SectionKind::getText());
-  ConstDataCoalSection = getMachOSection("\t__DATA,__const_coal,coalesced",
-                                         false, SectionKind::getText());
-  ConstDataSection = getMachOSection("\t.const_data", true,
-                                     SectionKind::getReadOnlyWithRel());
-  DataCoalSection = getMachOSection("\t__DATA,__datacoal_nt,coalesced",
-                                    false, SectionKind::getDataRel());
+  TextCoalSection
+    = getMachOSection("__TEXT", "__textcoal_nt",
+                      MCSectionMachO::S_COALESCED |
+                      MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+                      SectionKind::getText());
+  ConstTextCoalSection
+    = getMachOSection("__TEXT", "__const_coal", MCSectionMachO::S_COALESCED,
+                      SectionKind::getText());
+  ConstDataCoalSection
+    = getMachOSection("__DATA","__const_coal", MCSectionMachO::S_COALESCED,
+                      SectionKind::getText());
+  ConstDataSection  // .const_data
+    = getMachOSection("__DATA", "__const", 0,
+                      SectionKind::getReadOnlyWithRel());
+  DataCoalSection
+    = getMachOSection("__DATA","__datacoal_nt", MCSectionMachO::S_COALESCED,
+                      SectionKind::getDataRel());
 
   if (TM.getRelocationModel() == Reloc::Static) {
-    StaticCtorSection =
-      getMachOSection(".constructor", true, SectionKind::getDataRel());
-    StaticDtorSection =
-      getMachOSection(".destructor", true, SectionKind::getDataRel());
+    StaticCtorSection
+      = getMachOSection("__TEXT", "__constructor", 0,SectionKind::getDataRel());
+    StaticDtorSection
+      = getMachOSection("__TEXT", "__destructor", 0, SectionKind::getDataRel());
   } else {
-    StaticCtorSection =
-      getMachOSection(".mod_init_func", true, SectionKind::getDataRel());
-    StaticDtorSection =
-      getMachOSection(".mod_term_func", true, SectionKind::getDataRel());
+    StaticCtorSection
+      = getMachOSection("__DATA", "__mod_init_func",
+                        MCSectionMachO::S_MOD_INIT_FUNC_POINTERS,
+                        SectionKind::getDataRel());
+    StaticDtorSection
+      = getMachOSection("__DATA", "__mod_term_func", 
+                        MCSectionMachO::S_MOD_TERM_FUNC_POINTERS,
+                        SectionKind::getDataRel());
   }
   
   // Exception Handling.
-  LSDASection = getMachOSection("__DATA,__gcc_except_tab", false,
+  LSDASection = getMachOSection("__DATA", "__gcc_except_tab", 0,
                                 SectionKind::getDataRel());
   EHFrameSection =
-    getMachOSection("__TEXT,__eh_frame,coalesced,no_toc+strip_static_syms"
-                    "+live_support", false, SectionKind::getReadOnly());
+    getMachOSection("__TEXT", "__eh_frame",
+                    MCSectionMachO::S_COALESCED |
+                    MCSectionMachO::S_ATTR_NO_TOC |
+                    MCSectionMachO::S_ATTR_STRIP_STATIC_SYMS |
+                    MCSectionMachO::S_ATTR_LIVE_SUPPORT,
+                    SectionKind::getReadOnly());
 
   // Debug Information.
-  // FIXME: Don't use 'directive' syntax: need flags for debug/regular??
-  // FIXME: Need __DWARF segment.
   DwarfAbbrevSection = 
-    getMachOSection(".section __DWARF,__debug_abbrev,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_abbrev", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
   DwarfInfoSection =  
-    getMachOSection(".section __DWARF,__debug_info,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_info", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
   DwarfLineSection =  
-    getMachOSection(".section __DWARF,__debug_line,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_line", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
   DwarfFrameSection =  
-    getMachOSection(".section __DWARF,__debug_frame,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_frame", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
   DwarfPubNamesSection =  
-    getMachOSection(".section __DWARF,__debug_pubnames,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_pubnames", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
   DwarfPubTypesSection =  
-    getMachOSection(".section __DWARF,__debug_pubtypes,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_pubtypes", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
   DwarfStrSection =  
-    getMachOSection(".section __DWARF,__debug_str,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_str", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
   DwarfLocSection =  
-    getMachOSection(".section __DWARF,__debug_loc,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_loc", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
   DwarfARangesSection =  
-    getMachOSection(".section __DWARF,__debug_aranges,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_aranges", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
   DwarfRangesSection =  
-    getMachOSection(".section __DWARF,__debug_ranges,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_ranges", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
   DwarfMacroInfoSection =  
-    getMachOSection(".section __DWARF,__debug_macinfo,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_macinfo", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
   DwarfDebugInlineSection = 
-    getMachOSection(".section __DWARF,__debug_inlined,regular,debug", true,
+    getMachOSection("__DWARF", "__debug_inlined", MCSectionMachO::S_ATTR_DEBUG,
                     SectionKind::getMetadata());
 }
 
+/// getLazySymbolPointerSection - Return the section corresponding to
+/// the .lazy_symbol_pointer directive.
+const MCSection *TargetLoweringObjectFileMachO::
+getLazySymbolPointerSection() const {
+  return getMachOSection("__DATA", "__la_symbol_ptr",
+                         MCSectionMachO::S_LAZY_SYMBOL_POINTERS,
+                         SectionKind::getMetadata());
+}
+
+/// getNonLazySymbolPointerSection - Return the section corresponding to
+/// the .non_lazy_symbol_pointer directive.
+const MCSection *TargetLoweringObjectFileMachO::
+getNonLazySymbolPointerSection() const {
+  return getMachOSection("__DATA", "__nl_symbol_ptr",
+                         MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS,
+                         SectionKind::getMetadata());
+}
+
+
 const MCSection *TargetLoweringObjectFileMachO::
 getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind, 
                          Mangler *Mang, const TargetMachine &TM) const {
-  return getMachOSection(GV->getSection().c_str(), false, Kind);
+  // Parse the section specifier and create it if valid.
+  StringRef Segment, Section;
+  unsigned TAA, StubSize;
+  std::string ErrorCode =
+    MCSectionMachO::ParseSectionSpecifier(GV->getSection(), Segment, Section,
+                                          TAA, StubSize);
+  if (ErrorCode.empty())
+    return getMachOSection(Segment, Section, TAA, StubSize, Kind);
+  
+  
+  // If invalid, report the error with llvm_report_error.
+  llvm_report_error("Global variable '" + GV->getNameStr() +
+                    "' has an invalid section specifier '" + GV->getSection() +
+                    "': " + ErrorCode + ".");
+  // Fall back to dropping it into the data section.
+  return DataSection;
 }
 
 const MCSection *TargetLoweringObjectFileMachO::
diff --git a/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp b/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp
index 59cff0f..ae0e599 100644
--- a/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp
+++ b/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp
@@ -918,9 +918,11 @@
     // Output stubs for dynamically-linked functions
     if (!FnStubs.empty()) {
       const MCSection *TheSection = 
-      TLOFMacho.getMachOSection("\t.section __IMPORT,__jump_table,symbol_stubs,"
-                                "self_modifying_code+pure_instructions,5", true,
-                                SectionKind::getMetadata());
+        TLOFMacho.getMachOSection("__IMPORT", "__jump_table",
+                                  MCSectionMachO::S_SYMBOL_STUBS |
+                                  MCSectionMachO::S_ATTR_SELF_MODIFYING_CODE |
+                                  MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+                                  5, SectionKind::getMetadata());
       SwitchToSection(TheSection);
       for (StringMap<std::string>::iterator I = FnStubs.begin(),
            E = FnStubs.end(); I != E; ++I)
@@ -932,8 +934,8 @@
     // Output stubs for external and common global variables.
     if (!GVStubs.empty()) {
       const MCSection *TheSection = 
-        TLOFMacho.getMachOSection("\t.section __IMPORT,__pointers,"
-                                  "non_lazy_symbol_pointers", true,
+        TLOFMacho.getMachOSection("__IMPORT", "__pointers",
+                                  MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS,
                                   SectionKind::getMetadata());
       SwitchToSection(TheSection);
       for (StringMap<std::string>::iterator I = GVStubs.begin(),
diff --git a/test/CodeGen/ARM/ctors_dtors.ll b/test/CodeGen/ARM/ctors_dtors.ll
index 8ed98d9..714ca61 100644
--- a/test/CodeGen/ARM/ctors_dtors.ll
+++ b/test/CodeGen/ARM/ctors_dtors.ll
@@ -1,9 +1,9 @@
-; RUN: llvm-as <  %s | llc -mtriple=arm-apple-darwin | FileCheck %s -check-prefix=DARWIN
-; RUN: llvm-as  < %s | llc -mtriple=arm-linux-gnu | FileCheck %s -check-prefix=ELF
+; RUN: llvm-as < %s | llc -mtriple=arm-apple-darwin  | FileCheck %s -check-prefix=DARWIN
+; RUN: llvm-as < %s | llc -mtriple=arm-linux-gnu     | FileCheck %s -check-prefix=ELF
 ; RUN: llvm-as < %s | llc -mtriple=arm-linux-gnueabi | FileCheck %s -check-prefix=GNUEABI
 
-; DARWIN: .mod_init_func
-; DARWIN: .mod_term_func
+; DARWIN: .section	__DATA,__mod_init_func,mod_init_funcs
+; DARWIN: .section	__DATA,__mod_term_func,mod_term_funcs
 
 ; ELF: .section .ctors,"aw",%progbits
 ; ELF: .section .dtors,"aw",%progbits
diff --git a/test/CodeGen/ARM/stubs.ll b/test/CodeGen/ARM/stubs.ll
index 7c9cc23..baf6b7e 100644
--- a/test/CodeGen/ARM/stubs.ll
+++ b/test/CodeGen/ARM/stubs.ll
@@ -39,7 +39,7 @@
 ; PIC: L_exact_log2$slp:
 ; PIC: .long	L_exact_log2$lazy_ptr-(L_exact_log2$scv+8)
 
-; PIC: .lazy_symbol_pointer
+; PIC: .section __DATA,__la_symbol_ptr,lazy_symbol_pointers
 ; PIC: L_exact_log2$lazy_ptr:
 ; PIC: .indirect_symbol _exact_log2
 ; PIC: .long	dyld_stub_binding_helper
@@ -55,7 +55,7 @@
 ; DYNAMIC: L_exact_log2$slp:
 ; DYNAMIC: .long	L_exact_log2$lazy_ptr
 
-; DYNAMIC: .lazy_symbol_pointer
+; DYNAMIC: .section __DATA,__la_symbol_ptr,lazy_symbol_pointers
 ; DYNAMIC: L_exact_log2$lazy_ptr:
 ; DYNAMIC: .indirect_symbol _exact_log2
 ; DYNAMIC: .long	dyld_stub_binding_helper
diff --git a/test/CodeGen/PowerPC/available-externally.ll b/test/CodeGen/PowerPC/available-externally.ll
index e78d6a0..6c06529 100644
--- a/test/CodeGen/PowerPC/available-externally.ll
+++ b/test/CodeGen/PowerPC/available-externally.ll
@@ -44,7 +44,7 @@
 ; PIC: mtctr r12
 ; PIC: bctr
 
-; PIC: .lazy_symbol_pointer
+; PIC: .section __DATA,__la_symbol_ptr,lazy_symbol_pointers
 ; PIC: L_exact_log2$lazy_ptr:
 ; PIC: .indirect_symbol _exact_log2
 ; PIC: .long dyld_stub_binding_helper
@@ -60,7 +60,7 @@
 ; DYNAMIC: mtctr r12
 ; DYNAMIC: bctr
 
-; DYNAMIC: .lazy_symbol_pointer
+; DYNAMIC: .section __DATA,__la_symbol_ptr,lazy_symbol_pointers
 ; DYNAMIC: L_exact_log2$lazy_ptr:
 ; DYNAMIC: .indirect_symbol _exact_log2
 ; DYNAMIC: .long dyld_stub_binding_helper
diff --git a/test/CodeGen/X86/2009-01-27-NullStrings.ll b/test/CodeGen/X86/2009-01-27-NullStrings.ll
index b0c27d8..229d726 100644
--- a/test/CodeGen/X86/2009-01-27-NullStrings.ll
+++ b/test/CodeGen/X86/2009-01-27-NullStrings.ll
@@ -1,38 +1,7 @@
-; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin | grep {\\.cstring} | count 1
-	%struct.A = type {  }
-	%struct.NSString = type opaque
-	%struct.__builtin_CFString = type { i32*, i32, i8*, i32 }
-	%struct._objc_module = type { i32, i32, i8*, %struct._objc_symtab* }
-	%struct._objc_symtab = type { i32, %struct.objc_selector**, i16, i16 }
-	%struct.objc_object = type opaque
-	%struct.objc_selector = type opaque
-@"\01L_unnamed_cfstring_0" = internal constant %struct.__builtin_CFString { i32* getelementptr ([0 x i32]* @__CFConstantStringClassReference, i32 0, i32 0), i32 1992, i8* getelementptr ([1 x i8]* @"\01LC", i32 0, i32 0), i32 0 }, section "__DATA, __cfstring"		; <%struct.__builtin_CFString*> [#uses=1]
-@__CFConstantStringClassReference = external global [0 x i32]		; <[0 x i32]*> [#uses=1]
-@"\01LC" = internal constant [1 x i8] zeroinitializer		; <[1 x i8]*> [#uses=1]
-@"\01L_OBJC_SELECTOR_REFERENCES_0" = internal global %struct.objc_selector* bitcast ([6 x i8]* @"\01L_OBJC_METH_VAR_NAME_0" to %struct.objc_selector*), section "__OBJC,__message_refs,literal_pointers,no_dead_strip", align 4		; <%struct.objc_selector**> [#uses=2]
-@"\01L_OBJC_SYMBOLS" = internal global %struct._objc_symtab zeroinitializer, section "__OBJC,__symbols,regular,no_dead_strip", align 4		; <%struct._objc_symtab*> [#uses=2]
-@"\01L_OBJC_METH_VAR_NAME_0" = internal global [6 x i8] c"bork:\00", section "__TEXT,__cstring,cstring_literals", align 1		; <[6 x i8]*> [#uses=2]
-@"\01L_OBJC_IMAGE_INFO" = internal constant [2 x i32] zeroinitializer, section "__OBJC, __image_info,regular"		; <[2 x i32]*> [#uses=1]
-@"\01L_OBJC_CLASS_NAME_0" = internal global [1 x i8] zeroinitializer, section "__TEXT,__cstring,cstring_literals", align 1		; <[1 x i8]*> [#uses=1]
-@"\01L_OBJC_MODULES" = internal global %struct._objc_module { i32 7, i32 16, i8* getelementptr ([1 x i8]* @"\01L_OBJC_CLASS_NAME_0", i32 0, i32 0), %struct._objc_symtab* @"\01L_OBJC_SYMBOLS" }, section "__OBJC,__module_info,regular,no_dead_strip", align 4		; <%struct._objc_module*> [#uses=1]
-@llvm.used = appending global [6 x i8*] [ i8* bitcast (%struct.objc_selector** @"\01L_OBJC_SELECTOR_REFERENCES_0" to i8*), i8* bitcast (%struct._objc_symtab* @"\01L_OBJC_SYMBOLS" to i8*), i8* getelementptr ([6 x i8]* @"\01L_OBJC_METH_VAR_NAME_0", i32 0, i32 0), i8* bitcast ([2 x i32]* @"\01L_OBJC_IMAGE_INFO" to i8*), i8* getelementptr ([1 x i8]* @"\01L_OBJC_CLASS_NAME_0", i32 0, i32 0), i8* bitcast (%struct._objc_module* @"\01L_OBJC_MODULES" to i8*) ], section "llvm.metadata"		; <[6 x i8*]*> [#uses=0]
+; RUN: llvm-as < %s | llc -mtriple=i686-apple-darwin | FileCheck %s
+; CHECK: .section __TEXT,__cstring,cstring_literals
 
-define void @func(%struct.A* %a) nounwind {
-entry:
-	%a_addr = alloca %struct.A*		; <%struct.A**> [#uses=2]
-	%a.0 = alloca %struct.objc_object*		; <%struct.objc_object**> [#uses=2]
-	%"alloca point" = bitcast i32 0 to i32		; <i32> [#uses=0]
-	store %struct.A* %a, %struct.A** %a_addr
-	%0 = load %struct.A** %a_addr, align 4		; <%struct.A*> [#uses=1]
-	%1 = bitcast %struct.A* %0 to %struct.objc_object*		; <%struct.objc_object*> [#uses=1]
-	store %struct.objc_object* %1, %struct.objc_object** %a.0, align 4
-	%2 = load %struct.objc_selector** @"\01L_OBJC_SELECTOR_REFERENCES_0", align 4		; <%struct.objc_selector*> [#uses=1]
-	%3 = load %struct.objc_object** %a.0, align 4		; <%struct.objc_object*> [#uses=1]
-	call void bitcast (%struct.objc_object* (%struct.objc_object*, %struct.objc_selector*, ...)* @objc_msgSend to void (%struct.objc_object*, %struct.objc_selector*, %struct.NSString*)*)(%struct.objc_object* %3, %struct.objc_selector* %2, %struct.NSString* bitcast (%struct.__builtin_CFString* @"\01L_unnamed_cfstring_0" to %struct.NSString*)) nounwind
-	br label %return
+@x = internal constant [1 x i8] zeroinitializer		; <[1 x i8]*> [#uses=1]
 
-return:		; preds = %entry
-	ret void
-}
+@y = global [1 x i8]* @x
 
-declare %struct.objc_object* @objc_msgSend(%struct.objc_object*, %struct.objc_selector*, ...)
diff --git a/test/CodeGen/X86/global-sections.ll b/test/CodeGen/X86/global-sections.ll
index 7d39a02..0fcb17f 100644
--- a/test/CodeGen/X86/global-sections.ll
+++ b/test/CodeGen/X86/global-sections.ll
@@ -28,7 +28,7 @@
 ; int * const G3 = &G1;
 @G3 = constant i32* @G1
 
-; DARWIN: .const_data
+; DARWIN: .section        __DATA,__const
 ; DARWIN: .globl _G3
 ; DARWIN: _G3:
 ; DARWIN:     .long _G1
@@ -37,7 +37,7 @@
 ; _Complex long long const G4 = 34;
 @G4 = constant {i64,i64} { i64 34, i64 0 }
 
-; DARWIN: .const
+; DARWIN: .section        __TEXT,__const
 ; DARWIN: _G4:
 ; DARWIN:     .long 34
 
@@ -50,7 +50,7 @@
 ; LINUX: G5:
 ; LINUX:    .long 47
 
-; DARWIN: .data
+; DARWIN: .section        __DATA,__data
 ; DARWIN: .globl _G5
 ; DARWIN: _G5:
 ; DARWIN:    .long 47
@@ -88,7 +88,7 @@
 
 @G7 = constant [10 x i8] c"abcdefghi\00"
 
-; DARWIN:	.cstring
+; DARWIN:	__TEXT,__cstring,cstring_literals
 ; DARWIN:	.globl _G7
 ; DARWIN: _G7:
 ; DARWIN:	.asciz	"abcdefghi"
@@ -111,7 +111,7 @@
 
 @G9 = constant [4 x i32] [ i32 1, i32 2, i32 3, i32 0 ]
 
-; DARWIN:	.const
+; DARWIN:	.section        __TEXT,__const
 ; DARWIN:	.globl _G9
 ; DARWIN: _G9:
 
diff --git a/tools/llvm-mc/AsmLexer.cpp b/tools/llvm-mc/AsmLexer.cpp
index 28b0c1e..5b394b6 100644
--- a/tools/llvm-mc/AsmLexer.cpp
+++ b/tools/llvm-mc/AsmLexer.cpp
@@ -242,6 +242,17 @@
   return AsmToken(AsmToken::String, StringRef(TokStart, CurPtr - TokStart));
 }
 
+StringRef AsmLexer::LexUntilEndOfStatement() {
+  TokStart = CurPtr;
+
+  while (*CurPtr != '#' &&  // Start of line comment.
+         *CurPtr != ';' &&  // End of statement marker.
+         *CurPtr != '\n' &&
+         *CurPtr != '\r' &&
+         (*CurPtr != 0 || CurPtr != CurBuf->getBufferEnd()))
+    ++CurPtr;
+  return StringRef(TokStart, CurPtr-TokStart);
+}
 
 AsmToken AsmLexer::LexToken() {
   TokStart = CurPtr;
diff --git a/tools/llvm-mc/AsmLexer.h b/tools/llvm-mc/AsmLexer.h
index 4200137..905ff75 100644
--- a/tools/llvm-mc/AsmLexer.h
+++ b/tools/llvm-mc/AsmLexer.h
@@ -50,6 +50,9 @@
   ~AsmLexer();
   
   SMLoc getLoc() const;
+  
+  StringRef LexUntilEndOfStatement();
+  
 
   /// EnterIncludeFile - Enter the specified file. This returns true on failure.
   bool EnterIncludeFile(const std::string &Filename);
diff --git a/tools/llvm-mc/AsmParser.cpp b/tools/llvm-mc/AsmParser.cpp
index 8f6583a..153cdde 100644
--- a/tools/llvm-mc/AsmParser.cpp
+++ b/tools/llvm-mc/AsmParser.cpp
@@ -404,95 +404,104 @@
     if (IDVal == ".text")
       // FIXME: This changes behavior based on the -static flag to the
       // assembler.
-      return ParseDirectiveSectionSwitch("__TEXT,__text",
-                                         "regular,pure_instructions");
+      return ParseDirectiveSectionSwitch("__TEXT", "__text",
+                                     MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS);
     if (IDVal == ".const")
-      return ParseDirectiveSectionSwitch("__TEXT,__const");
+      return ParseDirectiveSectionSwitch("__TEXT", "__const", 0);
     if (IDVal == ".static_const")
-      return ParseDirectiveSectionSwitch("__TEXT,__static_const");
+      return ParseDirectiveSectionSwitch("__TEXT", "__static_const", 0);
     if (IDVal == ".cstring")
-      return ParseDirectiveSectionSwitch("__TEXT,__cstring", 
-                                         "cstring_literals");
+      return ParseDirectiveSectionSwitch("__TEXT","__cstring", 
+                                         MCSectionMachO::S_CSTRING_LITERALS);
     if (IDVal == ".literal4")
-      return ParseDirectiveSectionSwitch("__TEXT,__literal4", "4byte_literals");
+      return ParseDirectiveSectionSwitch("__TEXT", "__literal4",
+                                         MCSectionMachO::S_4BYTE_LITERALS);
     if (IDVal == ".literal8")
-      return ParseDirectiveSectionSwitch("__TEXT,__literal8", "8byte_literals");
+      return ParseDirectiveSectionSwitch("__TEXT", "__literal8",
+                                         MCSectionMachO::S_8BYTE_LITERALS);
     if (IDVal == ".literal16")
-      return ParseDirectiveSectionSwitch("__TEXT,__literal16",
-                                         "16byte_literals");
+      return ParseDirectiveSectionSwitch("__TEXT","__literal16",
+                                         MCSectionMachO::S_16BYTE_LITERALS);
     if (IDVal == ".constructor")
-      return ParseDirectiveSectionSwitch("__TEXT,__constructor");
+      return ParseDirectiveSectionSwitch("__TEXT","__constructor", 0);
     if (IDVal == ".destructor")
-      return ParseDirectiveSectionSwitch("__TEXT,__destructor");
+      return ParseDirectiveSectionSwitch("__TEXT","__destructor", 0);
     if (IDVal == ".fvmlib_init0")
-      return ParseDirectiveSectionSwitch("__TEXT,__fvmlib_init0");
+      return ParseDirectiveSectionSwitch("__TEXT","__fvmlib_init0", 0);
     if (IDVal == ".fvmlib_init1")
-      return ParseDirectiveSectionSwitch("__TEXT,__fvmlib_init1");
-    if (IDVal == ".symbol_stub") // FIXME: Different on PPC.
-      return ParseDirectiveSectionSwitch("__IMPORT,__jump_table,symbol_stubs",
-                                    "self_modifying_code+pure_instructions,5");
+      return ParseDirectiveSectionSwitch("__TEXT","__fvmlib_init1", 0);
+    if (IDVal == ".symbol_stub")
+      return ParseDirectiveSectionSwitch("__TEXT","__symbol_stub",
+                                         MCSectionMachO::S_SYMBOL_STUBS |
+                                    MCSectionMachO::S_ATTR_SELF_MODIFYING_CODE |
+                                       MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+                                          // FIXME: Different on PPC and ARM.
+                                         16);
     // FIXME: .picsymbol_stub on PPC.
     if (IDVal == ".data")
-      return ParseDirectiveSectionSwitch("__DATA,__data");
+      return ParseDirectiveSectionSwitch("__DATA", "__data", 0);
     if (IDVal == ".static_data")
-      return ParseDirectiveSectionSwitch("__DATA,__static_data");
+      return ParseDirectiveSectionSwitch("__DATA", "__static_data", 0);
     if (IDVal == ".non_lazy_symbol_pointer")
-      return ParseDirectiveSectionSwitch("__DATA,__nl_symbol_pointer",
-                                         "non_lazy_symbol_pointers");
+      return ParseDirectiveSectionSwitch("__DATA", "__nl_symbol_pointer",
+                                    MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS);
     if (IDVal == ".lazy_symbol_pointer")
-      return ParseDirectiveSectionSwitch("__DATA,__la_symbol_pointer",
-                                         "lazy_symbol_pointers");
+      return ParseDirectiveSectionSwitch("__DATA", "__la_symbol_pointer",
+                                         MCSectionMachO::S_LAZY_SYMBOL_POINTERS);
     if (IDVal == ".dyld")
-      return ParseDirectiveSectionSwitch("__DATA,__dyld");
+      return ParseDirectiveSectionSwitch("__DATA", "__dyld", 0);
     if (IDVal == ".mod_init_func")
-      return ParseDirectiveSectionSwitch("__DATA,__mod_init_func",
-                                         "mod_init_funcs");
+      return ParseDirectiveSectionSwitch("__DATA", "__mod_init_func",
+                                      MCSectionMachO::S_MOD_INIT_FUNC_POINTERS);
     if (IDVal == ".mod_term_func")
-      return ParseDirectiveSectionSwitch("__DATA,__mod_term_func",
-                                         "mod_term_funcs");
+      return ParseDirectiveSectionSwitch("__DATA", "__mod_term_func",
+                                      MCSectionMachO::S_MOD_TERM_FUNC_POINTERS);
     if (IDVal == ".const_data")
-      return ParseDirectiveSectionSwitch("__DATA,__const", "regular");
+      return ParseDirectiveSectionSwitch("__DATA", "__const", 0);
     
     
     // FIXME: Verify attributes on sections.
     if (IDVal == ".objc_class")
-      return ParseDirectiveSectionSwitch("__OBJC,__class");
+      return ParseDirectiveSectionSwitch("__OBJC", "__class", 0);
     if (IDVal == ".objc_meta_class")
-      return ParseDirectiveSectionSwitch("__OBJC,__meta_class");
+      return ParseDirectiveSectionSwitch("__OBJC", "__meta_class", 0);
     if (IDVal == ".objc_cat_cls_meth")
-      return ParseDirectiveSectionSwitch("__OBJC,__cat_cls_meth");
+      return ParseDirectiveSectionSwitch("__OBJC", "__cat_cls_meth", 0);
     if (IDVal == ".objc_cat_inst_meth")
-      return ParseDirectiveSectionSwitch("__OBJC,__cat_inst_meth");
+      return ParseDirectiveSectionSwitch("__OBJC", "__cat_inst_meth", 0);
     if (IDVal == ".objc_protocol")
-      return ParseDirectiveSectionSwitch("__OBJC,__protocol");
+      return ParseDirectiveSectionSwitch("__OBJC", "__protocol", 0);
     if (IDVal == ".objc_string_object")
-      return ParseDirectiveSectionSwitch("__OBJC,__string_object");
+      return ParseDirectiveSectionSwitch("__OBJC", "__string_object", 0);
     if (IDVal == ".objc_cls_meth")
-      return ParseDirectiveSectionSwitch("__OBJC,__cls_meth");
+      return ParseDirectiveSectionSwitch("__OBJC", "__cls_meth", 0);
     if (IDVal == ".objc_inst_meth")
-      return ParseDirectiveSectionSwitch("__OBJC,__inst_meth");
+      return ParseDirectiveSectionSwitch("__OBJC", "__inst_meth", 0);
     if (IDVal == ".objc_cls_refs")
-      return ParseDirectiveSectionSwitch("__OBJC,__cls_refs");
+      return ParseDirectiveSectionSwitch("__OBJC", "__cls_refs", 0);
     if (IDVal == ".objc_message_refs")
-      return ParseDirectiveSectionSwitch("__OBJC,__message_refs");
+      return ParseDirectiveSectionSwitch("__OBJC", "__message_refs", 0);
     if (IDVal == ".objc_symbols")
-      return ParseDirectiveSectionSwitch("__OBJC,__symbols");
+      return ParseDirectiveSectionSwitch("__OBJC", "__symbols", 0);
     if (IDVal == ".objc_category")
-      return ParseDirectiveSectionSwitch("__OBJC,__category");
+      return ParseDirectiveSectionSwitch("__OBJC", "__category", 0);
     if (IDVal == ".objc_class_vars")
-      return ParseDirectiveSectionSwitch("__OBJC,__class_vars");
+      return ParseDirectiveSectionSwitch("__OBJC", "__class_vars", 0);
     if (IDVal == ".objc_instance_vars")
-      return ParseDirectiveSectionSwitch("__OBJC,__instance_vars");
+      return ParseDirectiveSectionSwitch("__OBJC", "__instance_vars", 0);
     if (IDVal == ".objc_module_info")
-      return ParseDirectiveSectionSwitch("__OBJC,__module_info");
+      return ParseDirectiveSectionSwitch("__OBJC", "__module_info", 0);
     if (IDVal == ".objc_class_names")
-      return ParseDirectiveSectionSwitch("__TEXT,__cstring","cstring_literals");
+      return ParseDirectiveSectionSwitch("__TEXT", "__cstring",
+                                         MCSectionMachO::S_CSTRING_LITERALS);
     if (IDVal == ".objc_meth_var_types")
-      return ParseDirectiveSectionSwitch("__TEXT,__cstring","cstring_literals");
+      return ParseDirectiveSectionSwitch("__TEXT", "__cstring",
+                                         MCSectionMachO::S_CSTRING_LITERALS);
     if (IDVal == ".objc_meth_var_names")
-      return ParseDirectiveSectionSwitch("__TEXT,__cstring","cstring_literals");
+      return ParseDirectiveSectionSwitch("__TEXT", "__cstring",
+                                         MCSectionMachO::S_CSTRING_LITERALS);
     if (IDVal == ".objc_selector_strs")
-      return ParseDirectiveSectionSwitch("__OBJC,__selector_strs");
+      return ParseDirectiveSectionSwitch("__OBJC", "__selector_strs", 0);
     
     // Assembler features
     if (IDVal == ".set")
@@ -681,53 +690,52 @@
 bool AsmParser::ParseDirectiveDarwinSection() {
   StringRef SectionName;
 
-  if (ParseIdentifier(SectionName))
+  if (Lexer.isNot(AsmToken::Identifier))
     return TokError("expected identifier after '.section' directive");
   
-  std::string Section = SectionName;
-
-  // FIXME: This doesn't work, we lose quoting on things
-
-  // Accept a comma separated list of modifiers.
-  while (Lexer.is(AsmToken::Comma)) {
-    Lexer.Lex(); // Consume the comma.
-
-    StringRef ModifierName;    
-    if (ParseIdentifier(ModifierName))
-      return TokError("expected identifier in '.section' directive");
-    Section += ',';
-    Section += ModifierName;
-  }
-  
+  std::string SectionSpec = SectionName;
+  StringRef EOL = Lexer.LexUntilEndOfStatement();
+  SectionSpec.append(EOL.begin(), EOL.end());
+  Lexer.Lex();
   if (Lexer.isNot(AsmToken::EndOfStatement))
     return TokError("unexpected token in '.section' directive");
   Lexer.Lex();
 
+
+  StringRef Segment, Section;
+  unsigned TAA, StubSize;
+  std::string ErrorStr = 
+    MCSectionMachO::ParseSectionSpecifier(SectionSpec, Segment, Section,
+                                          TAA, StubSize);
+  
+  if (!ErrorStr.empty())
+    return TokError(ErrorStr.c_str());
+  
+  // FIXME: CACHE THESE.
+  
   // FIXME: Arch specific.
-  MCSection *S = Ctx.GetSection(Section);
+  MCSection *S = 0; //Ctx.GetSection(Section);
   if (S == 0)
-    S = MCSectionMachO::Create(Section, false, SectionKind(), Ctx);
+    S = MCSectionMachO::Create(Segment, Section, TAA, StubSize,
+                               SectionKind(), Ctx);
   
   Out.SwitchSection(S);
   return false;
 }
 
-bool AsmParser::ParseDirectiveSectionSwitch(const char *Section,
-                                            const char *Directives) {
+bool AsmParser::ParseDirectiveSectionSwitch(const char *Segment,
+                                            const char *Section,
+                                            unsigned TAA, unsigned StubSize) {
   if (Lexer.isNot(AsmToken::EndOfStatement))
     return TokError("unexpected token in section switching directive");
   Lexer.Lex();
   
-  std::string SectionStr = Section;
-  if (Directives && Directives[0]) {
-    SectionStr += ","; 
-    SectionStr += Directives;
-  }
-  
   // FIXME: Arch specific.
-  MCSection *S = Ctx.GetSection(Section);
+  // FIXME: Cache this!
+  MCSection *S = 0; // Ctx.GetSection(Section);
   if (S == 0)
-    S = MCSectionMachO::Create(Section, false, SectionKind(), Ctx);
+    S = MCSectionMachO::Create(Segment, Section, TAA, StubSize,
+                               SectionKind(), Ctx);
   
   Out.SwitchSection(S);
   return false;
@@ -1090,35 +1098,28 @@
 
   if (Lexer.isNot(AsmToken::Identifier))
     return TokError("expected segment name after '.zerofill' directive");
-  std::string Section = Lexer.getTok().getString();
+  StringRef Segment = Lexer.getTok().getString();
   Lexer.Lex();
 
   if (Lexer.isNot(AsmToken::Comma))
     return TokError("unexpected token in directive");
-  Section += ',';
   Lexer.Lex();
  
   if (Lexer.isNot(AsmToken::Identifier))
     return TokError("expected section name after comma in '.zerofill' "
                     "directive");
-  Section += Lexer.getTok().getString().str();
+  StringRef Section = Lexer.getTok().getString();
   Lexer.Lex();
 
-  // FIXME: we will need to tell GetSection() that this is to be created with or
-  // must have the Mach-O section type of S_ZEROFILL.  Something like the code
-  // below could be done but for now it is not as EmitZerofill() does not know
-  // how to deal with a section type in the section name like
-  // ParseDirectiveDarwinSection() allows.
-  // Section += ',';
-  // Section += "zerofill";
-
   // If this is the end of the line all that was wanted was to create the
   // the section but with no symbol.
   if (Lexer.is(AsmToken::EndOfStatement)) {
-    // FIXME: Arch specific.
-    MCSection *S = Ctx.GetSection(Section);
+    // FIXME: CACHE THIS.
+    MCSection *S = 0; //Ctx.GetSection(Section);
     if (S == 0)
-      S = MCSectionMachO::Create(Section, false, SectionKind(), Ctx);
+      S = MCSectionMachO::Create(Segment, Section,
+                                 MCSectionMachO::S_ZEROFILL, 0,
+                                 SectionKind(), Ctx);
     
     // Create the zerofill section but no symbol
     Out.EmitZerofill(S);
@@ -1176,9 +1177,12 @@
     return Error(IDLoc, "invalid symbol redefinition");
 
   // FIXME: Arch specific.
-  MCSection *S = Ctx.GetSection(Section);
+  // FIXME: CACHE.
+  MCSection *S = 0; //Ctx.GetSection(Section);
   if (S == 0)
-    S = MCSectionMachO::Create(Section, false, SectionKind(), Ctx);
+    S = MCSectionMachO::Create(Segment, Section,
+                               MCSectionMachO::S_ZEROFILL, 0,
+                               SectionKind(), Ctx);
   
   // Create the zerofill Symbol with Size and Pow2Alignment
   Out.EmitZerofill(S, Sym, Size, Pow2Alignment);
diff --git a/tools/llvm-mc/AsmParser.h b/tools/llvm-mc/AsmParser.h
index c6f6f63..646001c 100644
--- a/tools/llvm-mc/AsmParser.h
+++ b/tools/llvm-mc/AsmParser.h
@@ -99,8 +99,8 @@
   
   // Directive Parsing.
   bool ParseDirectiveDarwinSection(); // Darwin specific ".section".
-  bool ParseDirectiveSectionSwitch(const char *Section,
-                                   const char *Directives = 0);
+  bool ParseDirectiveSectionSwitch(const char *Segment, const char *Section,
+                                   unsigned TAA, unsigned StubSize = 0);
   bool ParseDirectiveAscii(bool ZeroTerminated); // ".ascii", ".asciiz"
   bool ParseDirectiveValue(unsigned Size); // ".byte", ".long", ...
   bool ParseDirectiveFill(); // ".fill"
diff --git a/tools/llvm-mc/llvm-mc.cpp b/tools/llvm-mc/llvm-mc.cpp
index 5f746f2..5bddea4 100644
--- a/tools/llvm-mc/llvm-mc.cpp
+++ b/tools/llvm-mc/llvm-mc.cpp
@@ -186,11 +186,10 @@
   OwningPtr<MCStreamer> Str(createAsmStreamer(Ctx, outs()));
 
   // FIXME: Target hook & command line option for initial section.
-  Str.get()->SwitchSection(MCSectionMachO::Create("__TEXT,__text,"
-                                             "regular,pure_instructions",
-                                             false,
-                                            SectionKind::getText(),
-                                             Ctx));
+  Str.get()->SwitchSection(MCSectionMachO::Create("__TEXT","__text",
+                                       MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+                                                  0, SectionKind::getText(),
+                                                  Ctx));
 
   AsmParser Parser(SrcMgr, Ctx, *Str.get());
   OwningPtr<TargetAsmParser> TAP(GetTargetAsmParser(ProgName, Parser));