diff --git a/lld/MachO/Config.h b/lld/MachO/Config.h
--- a/lld/MachO/Config.h
+++ b/lld/MachO/Config.h
@@ -92,6 +92,7 @@
   bool emitBitcodeBundle = false;
   bool emitEncryptionInfo = false;
   bool timeTraceEnabled = false;
+  bool dataConst = false;
   uint32_t headerPad;
   uint32_t dylibCompatibilityVersion = 0;
   uint32_t dylibCurrentVersion = 0;
diff --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -558,6 +558,33 @@
   }
 }
 
+static void initializeSectionRenameMap() {
+  if (config->dataConst) {
+    SmallVector<StringRef> v{section_names::got,
+                             section_names::authGot,
+                             section_names::authPtr,
+                             section_names::nonLazySymbolPtr,
+                             section_names::const_,
+                             section_names::cfString,
+                             section_names::moduleInitFunc,
+                             section_names::moduleTermFunc,
+                             section_names::objcClassList,
+                             section_names::objcNonLazyClassList,
+                             section_names::objcCatList,
+                             section_names::objcNonLazyCatList,
+                             section_names::objcProtoList,
+                             section_names::objcImageInfo};
+    for (StringRef s : v)
+      config->sectionRenameMap[{segment_names::data, s}] = {
+          segment_names::dataConst, s};
+  }
+  config->sectionRenameMap[{segment_names::text, section_names::staticInit}] = {
+      segment_names::text, section_names::text};
+  config->sectionRenameMap[{segment_names::import, section_names::pointers}] = {
+      config->dataConst ? segment_names::dataConst : segment_names::data,
+      section_names::nonLazySymbolPtr};
+}
+
 static inline char toLowerDash(char x) {
   if (x >= 'A' && x <= 'Z')
     return x - 'A' + 'a';
@@ -757,6 +784,26 @@
   return prot;
 }
 
+static bool dataConstDefault(const InputArgList &args) {
+  switch (config->outputType) {
+  case MH_EXECUTE:
+    return !args.hasArg(OPT_no_pie);
+  case MH_BUNDLE:
+    // FIXME: return false when -final_name ...
+    // has prefix "/System/Library/UserEventPlugins/"
+    // or matches "/usr/libexec/locationd" "/usr/libexec/terminusd"
+    return true;
+  case MH_DYLIB:
+    return true;
+  case MH_OBJECT:
+    return false;
+  default:
+    llvm_unreachable(
+        "unsupported output type for determining data-const default");
+  }
+  return false;
+}
+
 void SymbolPatterns::clear() {
   literals.clear();
   globs.clear();
@@ -1002,6 +1049,11 @@
       parseDylibVersion(args, OPT_compatibility_version);
   config->dylibCurrentVersion = parseDylibVersion(args, OPT_current_version);
 
+  config->dataConst =
+      args.hasFlag(OPT_data_const, OPT_no_data_const, dataConstDefault(args));
+  // Populate config->sectionRenameMap with builtin default renames.
+  // Options -rename_section and -rename_segment are able to override.
+  initializeSectionRenameMap();
   // Reject every special character except '.' and '$'
   // TODO(gkm): verify that this is the proper set of invalid chars
   StringRef invalidNameChars("!\"#%&'()*+,-/:;<=>?@[\\]^`{|}~");
diff --git a/lld/MachO/MergedOutputSection.h b/lld/MachO/MergedOutputSection.h
--- a/lld/MachO/MergedOutputSection.h
+++ b/lld/MachO/MergedOutputSection.h
@@ -44,7 +44,7 @@
   }
 
 private:
-  void mergeFlags(uint32_t inputFlags);
+  void mergeFlags(InputSection *input);
 
   size_t size = 0;
   uint64_t fileSize = 0;
diff --git a/lld/MachO/MergedOutputSection.cpp b/lld/MachO/MergedOutputSection.cpp
--- a/lld/MachO/MergedOutputSection.cpp
+++ b/lld/MachO/MergedOutputSection.cpp
@@ -7,9 +7,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "MergedOutputSection.h"
+#include "OutputSegment.h"
 #include "lld/Common/ErrorHandler.h"
 #include "lld/Common/Memory.h"
 #include "llvm/BinaryFormat/MachO.h"
+#include "llvm/Support/ScopedPrinter.h"
 
 using namespace llvm;
 using namespace llvm::MachO;
@@ -21,8 +23,8 @@
     align = input->align;
     flags = input->flags;
   } else {
-    mergeFlags(input->flags);
     align = std::max(align, input->align);
+    mergeFlags(input);
   }
 
   inputs.push_back(input);
@@ -52,21 +54,25 @@
 // TODO: this is most likely wrong; reconsider how section flags
 // are actually merged. The logic presented here was written without
 // any form of informed research.
-void MergedOutputSection::mergeFlags(uint32_t inputFlags) {
-  uint8_t sectionFlag = SECTION_TYPE & inputFlags;
-  if (sectionFlag != (SECTION_TYPE & flags))
-    error("Cannot add merge section; inconsistent type flags " +
-          Twine(sectionFlag));
+void MergedOutputSection::mergeFlags(InputSection *input) {
+  uint8_t baseType = flags & SECTION_TYPE;
+  uint8_t inputType = input->flags & SECTION_TYPE;
+  if (baseType != inputType)
+    error("Cannot merge section " + input->name + " (type=0x" +
+          to_hexString(inputType) + ") into " + name + " (type=0x" +
+          to_hexString(baseType) + "): inconsistent types");
 
-  uint32_t inconsistentFlags = S_ATTR_DEBUG | S_ATTR_STRIP_STATIC_SYMS |
-                               S_ATTR_NO_DEAD_STRIP | S_ATTR_LIVE_SUPPORT;
-  if ((inputFlags ^ flags) & inconsistentFlags)
-    error("Cannot add merge section; cannot merge inconsistent flags");
+  constexpr uint32_t strictFlags = S_ATTR_DEBUG | S_ATTR_STRIP_STATIC_SYMS |
+                                   S_ATTR_NO_DEAD_STRIP | S_ATTR_LIVE_SUPPORT;
+  if ((input->flags ^ flags) & strictFlags)
+    error("Cannot merge section " + input->name + " (flags=0x" +
+          to_hexString(input->flags) + ") into " + name + " (flags=0x" +
+          to_hexString(flags) + "): strict flags differ");
 
   // Negate pure instruction presence if any section isn't pure.
-  uint32_t pureMask = ~S_ATTR_PURE_INSTRUCTIONS | (inputFlags & flags);
+  uint32_t pureMask = ~S_ATTR_PURE_INSTRUCTIONS | (input->flags & flags);
 
   // Merge the rest
-  flags |= inputFlags;
+  flags |= input->flags;
   flags &= pureMask;
 }
diff --git a/lld/MachO/Options.td b/lld/MachO/Options.td
--- a/lld/MachO/Options.td
+++ b/lld/MachO/Options.td
@@ -635,6 +635,16 @@
     HelpText<"Show where and why symbols move, as specified by -move_to_ro_segment, -move_to_rw_segment, -rename_section, and -rename_segment">,
     Flags<[HelpHidden]>,
     Group<grp_rare>;
+def data_const : Flag<["-"], "data_const">,
+    HelpText<"Force migration of readonly data into __DATA_CONST segment">,
+    Group<grp_rare>;
+def no_data_const : Flag<["-"], "no_data_const">,
+    HelpText<"Block migration of readonly data away from __DATA segment">,
+    Group<grp_rare>;
+def text_exec : Flag<["-"], "text_exec">,
+    HelpText<"Rename __segment TEXT to __TEXT_EXEC for sections __text and __stubs">,
+    Flags<[HelpHidden]>,
+    Group<grp_rare>;
 def section_order : MultiArg<["-"], "section_order", 2>,
     MetaVarName<"<segment> <sections>">,
     HelpText<"With -preload, specify layout sequence of colon-separated <sections> in <segment>">,
@@ -1134,14 +1144,6 @@
     HelpText<"This option is undocumented in ld64">,
     Flags<[HelpHidden]>,
     Group<grp_undocumented>;
-def data_const : Flag<["-"], "data_const">,
-    HelpText<"This option is undocumented in ld64">,
-    Flags<[HelpHidden]>,
-    Group<grp_undocumented>;
-def no_data_const : Flag<["-"], "no_data_const">,
-    HelpText<"This option is undocumented in ld64">,
-    Flags<[HelpHidden]>,
-    Group<grp_undocumented>;
 def data_in_code_info : Flag<["-"], "data_in_code_info">,
     HelpText<"This option is undocumented in ld64">,
     Flags<[HelpHidden]>,
@@ -1286,10 +1288,6 @@
     HelpText<"This option is undocumented in ld64">,
     Flags<[HelpHidden]>,
     Group<grp_undocumented>;
-def text_exec : Flag<["-"], "text_exec">,
-    HelpText<"This option is undocumented in ld64">,
-    Flags<[HelpHidden]>,
-    Group<grp_undocumented>;
 def threaded_starts_section : Flag<["-"], "threaded_starts_section">,
     HelpText<"This option is undocumented in ld64">,
     Flags<[HelpHidden]>,
diff --git a/lld/MachO/Writer.cpp b/lld/MachO/Writer.cpp
--- a/lld/MachO/Writer.cpp
+++ b/lld/MachO/Writer.cpp
@@ -774,7 +774,8 @@
         .Case(section_names::unwindInfo, std::numeric_limits<int>::max() - 1)
         .Case(section_names::ehFrame, std::numeric_limits<int>::max())
         .Default(0);
-  } else if (segname == segment_names::data) {
+  } else if (segname == segment_names::data ||
+             segname == segment_names::dataConst) {
     // For each thread spawned, dyld will initialize its TLVs by copying the
     // address range from the start of the first thread-local data section to
     // the end of the last one. We therefore arrange these sections contiguously
diff --git a/lld/test/MachO/builtin-rename.s b/lld/test/MachO/builtin-rename.s
new file mode 100644
--- /dev/null
+++ b/lld/test/MachO/builtin-rename.s
@@ -0,0 +1,170 @@
+# REQUIRES: x86
+# RUN: rm -rf %t; split-file %s %t
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin \
+# RUN:     %t/main.s -o %t/main.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin \
+# RUN:     %t/renames.s -o %t/renames.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin \
+# RUN:     %t/error.s -o %t/error.o
+
+# RUN: not %lld            -o %t/error %t/main.o %t/error.o -lSystem 2>&1 | \
+# RUN:     FileCheck %s --check-prefix=ERROR
+
+## Check the error diagnostic for merging mismatched section types
+# ERROR: Cannot merge section __pointers (type=0x0) into __nl_symbol_ptr (type=0x6): inconsistent types
+
+## Check that section and segment renames happen as expected
+# RUN: %lld                -o %t/ydata %t/main.o %t/renames.o -lSystem
+# RUN: %lld -no_data_const -o %t/ndata %t/main.o %t/renames.o -lSystem
+# RUN: %lld -no_pie        -o %t/nopie %t/main.o %t/renames.o -lSystem
+
+# RUN: llvm-objdump --syms %t/ydata | \
+# RUN:     FileCheck %s --check-prefixes=CHECK,YDATA
+# RUN: llvm-objdump --syms %t/ndata | \
+# RUN:     FileCheck %s --check-prefixes=CHECK,NDATA
+# RUN: llvm-objdump --syms %t/nopie | \
+# RUN:     FileCheck %s --check-prefixes=CHECK,NDATA
+
+# CHECK-LABEL: {{^}}SYMBOL TABLE:
+
+# CHECK-DAG: __TEXT,__text __TEXT__StaticInit
+
+# NDATA-DAG: __DATA,__auth_got __DATA__auth_got
+# NDATA-DAG: __DATA,__auth_ptr __DATA__auth_ptr
+# NDATA-DAG: __DATA,__nl_symbol_ptr __DATA__nl_symbol_ptr
+# NDATA-DAG: __DATA,__const __DATA__const
+# NDATA-DAG: __DATA,__cfstring __DATA__cfstring
+# NDATA-DAG: __DATA,__mod_init_func __DATA__mod_init_func
+# NDATA-DAG: __DATA,__mod_term_func __DATA__mod_term_func
+# NDATA-DAG: __DATA,__objc_classlist __DATA__objc_classlist
+# NDATA-DAG: __DATA,__objc_nlclslist __DATA__objc_nlclslist
+# NDATA-DAG: __DATA,__objc_catlist __DATA__objc_catlist
+# NDATA-DAG: __DATA,__objc_nlcatlist __DATA__objc_nlcatlist
+# NDATA-DAG: __DATA,__objc_protolist __DATA__objc_protolist
+# NDATA-DAG: __DATA,__objc_imageinfo __DATA__objc_imageinfo
+# NDATA-DAG: __DATA,__nl_symbol_ptr __IMPORT__pointers
+
+# YDATA-DAG: __DATA_CONST,__auth_got __DATA__auth_got
+# YDATA-DAG: __DATA_CONST,__auth_ptr __DATA__auth_ptr
+# YDATA-DAG: __DATA_CONST,__nl_symbol_ptr __DATA__nl_symbol_ptr
+# YDATA-DAG: __DATA_CONST,__const __DATA__const
+# YDATA-DAG: __DATA_CONST,__cfstring __DATA__cfstring
+# YDATA-DAG: __DATA_CONST,__mod_init_func __DATA__mod_init_func
+# YDATA-DAG: __DATA_CONST,__mod_term_func __DATA__mod_term_func
+# YDATA-DAG: __DATA_CONST,__objc_classlist __DATA__objc_classlist
+# YDATA-DAG: __DATA_CONST,__objc_nlclslist __DATA__objc_nlclslist
+# YDATA-DAG: __DATA_CONST,__objc_catlist __DATA__objc_catlist
+# YDATA-DAG: __DATA_CONST,__objc_nlcatlist __DATA__objc_nlcatlist
+# YDATA-DAG: __DATA_CONST,__objc_protolist __DATA__objc_protolist
+# YDATA-DAG: __DATA_CONST,__objc_imageinfo __DATA__objc_imageinfo
+# YDATA-DAG: __DATA_CONST,__nl_symbol_ptr __IMPORT__pointers
+
+#--- renames.s
+.section __DATA,__auth_got
+.global __DATA__auth_got
+__DATA__auth_got:
+  .space 8
+
+.section __DATA,__auth_ptr
+.global __DATA__auth_ptr
+__DATA__auth_ptr:
+  .space 8
+
+.section __DATA,__nl_symbol_ptr
+.global __DATA__nl_symbol_ptr
+__DATA__nl_symbol_ptr:
+  .space 8
+
+.section __DATA,__const
+.global __DATA__const
+__DATA__const:
+  .space 8
+
+.section __DATA,__cfstring
+.global __DATA__cfstring
+__DATA__cfstring:
+  .space 8
+
+# FIXME: error: conflicts with synthetic section ...
+# FIXME: we can't explicitly define syms in synthetic sections
+# COM: .section __DATA,__got
+# COM: .global __DATA__got
+# COM: __DATA__got:
+# COM:   .space 8
+
+.section __DATA,__mod_init_func,mod_init_funcs
+.global __DATA__mod_init_func
+__DATA__mod_init_func:
+  .space 8
+
+.section __DATA,__mod_term_func,mod_term_funcs
+.global __DATA__mod_term_func
+__DATA__mod_term_func:
+  .space 8
+
+.section __DATA,__objc_classlist
+.global __DATA__objc_classlist
+__DATA__objc_classlist:
+  .space 8
+
+.section __DATA,__objc_nlclslist
+.global __DATA__objc_nlclslist
+__DATA__objc_nlclslist:
+  .space 8
+
+.section __DATA,__objc_catlist
+.global __DATA__objc_catlist
+__DATA__objc_catlist:
+  .space 8
+
+.section __DATA,__objc_nlcatlist
+.global __DATA__objc_nlcatlist
+__DATA__objc_nlcatlist:
+  .space 8
+
+.section __DATA,__objc_protolist
+.global __DATA__objc_protolist
+__DATA__objc_protolist:
+  .space 8
+
+.section __DATA,__objc_imageinfo
+.global __DATA__objc_imageinfo
+__DATA__objc_imageinfo:
+  .space 8
+
+# FIXME: error: conflicts with synthetic section ...
+# FIXME: we can't explicitly define syms in synthetic sections
+# COM: .section __DATA,__la_symbol_ptr,lazy_symbol_pointers
+# COM: .global __DATA__la_symbol_ptr
+# COM: __DATA__la_symbol_ptr:
+# COM:   .space 8
+
+.section __IMPORT,__pointers,non_lazy_symbol_pointers
+.global __IMPORT__pointers
+__IMPORT__pointers:
+  .space 8
+
+.section __TEXT,__StaticInit
+.section __TEXT,__StaticInit
+.global __TEXT__StaticInit
+__TEXT__StaticInit:
+  .space 8
+
+#--- error.s
+
+.section __DATA,__nl_symbol_ptr
+.global __DATA__nl_symbol_ptr
+__DATA__nl_symbol_ptr:
+  .space 8
+
+.section __IMPORT,__pointers
+.global __IMPORT__pointers
+__IMPORT__pointers:
+  .space 8
+
+#--- main.s
+.text
+.global _main
+_main:
+  ret
diff --git a/lld/test/MachO/load-command-sequence.s b/lld/test/MachO/load-command-sequence.s
--- a/lld/test/MachO/load-command-sequence.s
+++ b/lld/test/MachO/load-command-sequence.s
@@ -28,14 +28,14 @@
 # COMMON: segname __TEXT
 # COMMON: cmd LC_SEGMENT_64
 # COMMON: segname __DATA_CONST
+# COMMON: sectname __const
+# COMMON: segname __DATA_CONST
 # COMMON: sectname __got
 # COMMON: segname __DATA_CONST
 # COMMON: cmd LC_SEGMENT_64
 # COMMON: segname __DATA
 # COMMON: sectname __data
 # COMMON: segname __DATA
-# COMMON: sectname __const
-# COMMON: segname __DATA
 # COMMON: cmd LC_SEGMENT_64
 # COMMON: segname __LINKEDIT
 # COMMON: cmd LC_DYLD_INFO_ONLY
diff --git a/lld/test/MachO/local-got.s b/lld/test/MachO/local-got.s
--- a/lld/test/MachO/local-got.s
+++ b/lld/test/MachO/local-got.s
@@ -8,7 +8,7 @@
 
 # RUN: %lld -lSystem -o %t/test %t/test.o -L%t -lhello
 # RUN: llvm-objdump --macho --full-contents --rebase --bind %t/test | FileCheck %s --check-prefixes=CHECK,PIE --match-full-lines
-# RUN: %lld -no_pie -lSystem -o %t/test %t/test.o -L%t -lhello
+# RUN: %lld -no_pie -data_const -lSystem -o %t/test %t/test.o -L%t -lhello
 # RUN: llvm-objdump --macho --full-contents --rebase --bind %t/test | FileCheck %s --check-prefixes=CHECK,NO-PIE --match-full-lines
 
 ## Check that the GOT references the cstrings. --full-contents displays the
diff --git a/lld/test/MachO/x86-64-relocs.s b/lld/test/MachO/x86-64-relocs.s
--- a/lld/test/MachO/x86-64-relocs.s
+++ b/lld/test/MachO/x86-64-relocs.s
@@ -20,7 +20,7 @@
 # CHECK-NEXT:  [[#%x, CSTRING_ADDR + 22 - LSTR_OFF]]
 
 # RUN: llvm-objdump --section=__const --full-contents %t | FileCheck %s --check-prefix=NONPCREL
-# NONPCREL:      Contents of section __DATA,__const:
+# NONPCREL:      Contents of section __DATA_CONST,__const:
 # NONPCREL-NEXT: 100001000 18040000 01000000 18040000 01000000
 
 .section __TEXT,__text
diff --git a/lld/test/MachO/x86-64-stubs.s b/lld/test/MachO/x86-64-stubs.s
--- a/lld/test/MachO/x86-64-stubs.s
+++ b/lld/test/MachO/x86-64-stubs.s
@@ -12,7 +12,7 @@
 # RUN:   -o %t/libgoodbye.dylib
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t/dylink-lazy.o
-# RUN: %lld -no_pie -o %t/dylink-lazy-no-pie \
+# RUN: %lld -no_pie -data_const -o %t/dylink-lazy-no-pie \
 # RUN:   -L%t -lhello -lgoodbye %t/dylink-lazy.o -lSystem
 
 ## When looking at the __stubs section alone, we are unable to easily tell which