Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_asm.h
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_asm.h
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_asm.h
@@ -43,4 +43,16 @@
 # define CFI_RESTORE(reg)
 #endif
 
-
+#if !defined(__APPLE__)
+# define ASM_HIDDEN(symbol) .hidden symbol
+# define ASM_TYPE_FUNCTION(symbol) .type symbol, @function
+# define ASM_SIZE(symbol) .size symbol, .-symbol
+# define ASM_TSAN_SYMBOL(symbol) symbol
+# define ASM_TSAN_SYMBOL_INTERCEPTOR(symbol) symbol
+#else
+# define ASM_HIDDEN(symbol)
+# define ASM_TYPE_FUNCTION(symbol)
+# define ASM_SIZE(symbol)
+# define ASM_TSAN_SYMBOL(symbol) _##symbol
+# define ASM_TSAN_SYMBOL_INTERCEPTOR(symbol) _wrap_##symbol
+#endif
Index: compiler-rt/trunk/lib/tsan/CMakeLists.txt
===================================================================
--- compiler-rt/trunk/lib/tsan/CMakeLists.txt
+++ compiler-rt/trunk/lib/tsan/CMakeLists.txt
@@ -95,11 +95,19 @@
   CFLAGS ${TSAN_RTL_CFLAGS})
 
 if(APPLE)
+  set(TSAN_ASM_SOURCES rtl/tsan_rtl_amd64.S)
+  # Xcode will try to compile this file as C ('clang -x c'), and that will fail.
+  if (${CMAKE_GENERATOR} STREQUAL "Xcode")
+    enable_language(ASM)
+  else()
+    # Pass ASM file directly to the C++ compiler.
+    set_source_files_properties(${TSAN_ASM_SOURCES} PROPERTIES LANGUAGE C)
+  endif()
   add_compiler_rt_runtime(clang_rt.tsan
     SHARED
     OS ${TSAN_SUPPORTED_OS}
     ARCHS ${TSAN_SUPPORTED_ARCH}
-    SOURCES ${TSAN_SOURCES} ${TSAN_CXX_SOURCES}
+    SOURCES ${TSAN_SOURCES} ${TSAN_CXX_SOURCES} ${TSAN_ASM_SOURCES}
     OBJECT_LIBS RTInterception
                 RTSanitizerCommon
                 RTSanitizerCommonLibc
Index: compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc
===================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc
@@ -440,7 +440,7 @@
 }
 
 static void LongJmp(ThreadState *thr, uptr *env) {
-#if SANITIZER_FREEBSD
+#if SANITIZER_FREEBSD || SANITIZER_MAC
   uptr mangled_sp = env[2];
 #elif defined(SANITIZER_LINUX)
 # ifdef __aarch64__
@@ -478,6 +478,11 @@
   SetJmp(cur_thread(), sp, mangled_sp);
 }
 
+#if SANITIZER_MAC
+TSAN_INTERCEPTOR(int, setjmp, void *env);
+TSAN_INTERCEPTOR(int, _setjmp, void *env);
+TSAN_INTERCEPTOR(int, sigsetjmp, void *env);
+#else  // SANITIZER_MAC
 // Not called.  Merely to satisfy TSAN_INTERCEPT().
 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
 int __interceptor_setjmp(void *env);
@@ -516,6 +521,7 @@
 DEFINE_REAL(int, _setjmp, void *env)
 DEFINE_REAL(int, sigsetjmp, void *env)
 DEFINE_REAL(int, __sigsetjmp, void *env)
+#endif  // SANITIZER_MAC
 
 TSAN_INTERCEPTOR(void, longjmp, uptr *env, int val) {
   {
Index: compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_amd64.S
===================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_amd64.S
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_amd64.S
@@ -1,9 +1,13 @@
 #include "sanitizer_common/sanitizer_asm.h"
+#if !defined(__APPLE__)
 .section .text
+#else
+.section __TEXT,__text
+#endif
 
-.hidden __tsan_trace_switch
-.globl __tsan_trace_switch_thunk
-__tsan_trace_switch_thunk:
+ASM_HIDDEN(__tsan_trace_switch)
+.globl ASM_TSAN_SYMBOL(__tsan_trace_switch_thunk)
+ASM_TSAN_SYMBOL(__tsan_trace_switch_thunk):
   CFI_STARTPROC
   # Save scratch registers.
   push %rax
@@ -42,7 +46,7 @@
   shr $4, %rsp  # clear 4 lsb, align to 16
   shl $4, %rsp
 
-  call __tsan_trace_switch
+  call ASM_TSAN_SYMBOL(__tsan_trace_switch)
 
   # Unalign stack frame back.
   mov %rbx, %rsp  # restore the original rsp
@@ -81,9 +85,9 @@
   ret
   CFI_ENDPROC
 
-.hidden __tsan_report_race
-.globl __tsan_report_race_thunk
-__tsan_report_race_thunk:
+ASM_HIDDEN(__tsan_report_race)
+.globl ASM_TSAN_SYMBOL(__tsan_report_race_thunk)
+ASM_TSAN_SYMBOL(__tsan_report_race_thunk):
   CFI_STARTPROC
   # Save scratch registers.
   push %rax
@@ -122,7 +126,7 @@
   shr $4, %rsp  # clear 4 lsb, align to 16
   shl $4, %rsp
 
-  call __tsan_report_race
+  call ASM_TSAN_SYMBOL(__tsan_report_race)
 
   # Unalign stack frame back.
   mov %rbx, %rsp  # restore the original rsp
@@ -161,11 +165,13 @@
   ret
   CFI_ENDPROC
 
-.hidden __tsan_setjmp
+ASM_HIDDEN(__tsan_setjmp)
+#if !defined(__APPLE__)
 .comm _ZN14__interception11real_setjmpE,8,8
-.globl setjmp
-.type setjmp, @function
-setjmp:
+#endif
+.globl ASM_TSAN_SYMBOL_INTERCEPTOR(setjmp)
+ASM_TYPE_FUNCTION(ASM_TSAN_SYMBOL_INTERCEPTOR(setjmp))
+ASM_TSAN_SYMBOL_INTERCEPTOR(setjmp):
   CFI_STARTPROC
   // save env parameter
   push %rdi
@@ -175,29 +181,38 @@
 #if defined(__FreeBSD__)
   lea 8(%rsp), %rdi
   mov %rdi, %rsi
-#else
+#elif defined(__APPLE__)
+  lea 16(%rsp), %rdi
+  mov %rdi, %rsi
+#elif defined(__linux__)
   lea 16(%rsp), %rdi
   mov %rdi, %rsi
   xor %fs:0x30, %rsi  // magic mangling of rsp (see libc setjmp)
   rol $0x11, %rsi
+#else
+# error "Unknown platform"
 #endif
   // call tsan interceptor
-  call __tsan_setjmp
+  call ASM_TSAN_SYMBOL(__tsan_setjmp)
   // restore env parameter
   pop %rdi
   CFI_ADJUST_CFA_OFFSET(-8)
   CFI_RESTORE(%rdi)
   // tail jump to libc setjmp
   movl $0, %eax
+#if !defined(__APPLE__)
   movq _ZN14__interception11real_setjmpE@GOTPCREL(%rip), %rdx
   jmp *(%rdx)
+#else
+  jmp ASM_TSAN_SYMBOL(setjmp)
+#endif
   CFI_ENDPROC
-.size setjmp, .-setjmp
+ASM_SIZE(ASM_TSAN_SYMBOL_INTERCEPTOR(setjmp))
 
 .comm _ZN14__interception12real__setjmpE,8,8
-.globl _setjmp
-.type _setjmp, @function
-_setjmp:
+.globl ASM_TSAN_SYMBOL_INTERCEPTOR(_setjmp)
+ASM_TYPE_FUNCTION(ASM_TSAN_SYMBOL_INTERCEPTOR(_setjmp))
+ASM_TSAN_SYMBOL_INTERCEPTOR(_setjmp):
   CFI_STARTPROC
   // save env parameter
   push %rdi
@@ -207,29 +222,38 @@
 #if defined(__FreeBSD__)
   lea 8(%rsp), %rdi
   mov %rdi, %rsi
-#else
+#elif defined(__APPLE__)
+  lea 16(%rsp), %rdi
+  mov %rdi, %rsi
+#elif defined(__linux__)
   lea 16(%rsp), %rdi
   mov %rdi, %rsi
   xor %fs:0x30, %rsi  // magic mangling of rsp (see libc setjmp)
   rol $0x11, %rsi
+#else
+# error "Unknown platform"
 #endif
   // call tsan interceptor
-  call __tsan_setjmp
+  call ASM_TSAN_SYMBOL(__tsan_setjmp)
   // restore env parameter
   pop %rdi
   CFI_ADJUST_CFA_OFFSET(-8)
   CFI_RESTORE(%rdi)
   // tail jump to libc setjmp
   movl $0, %eax
+#if !defined(__APPLE__)
   movq _ZN14__interception12real__setjmpE@GOTPCREL(%rip), %rdx
   jmp *(%rdx)
+#else
+  jmp ASM_TSAN_SYMBOL(_setjmp)
+#endif
   CFI_ENDPROC
-.size _setjmp, .-_setjmp
+ASM_SIZE(ASM_TSAN_SYMBOL_INTERCEPTOR(_setjmp))
 
 .comm _ZN14__interception14real_sigsetjmpE,8,8
-.globl sigsetjmp
-.type sigsetjmp, @function
-sigsetjmp:
+.globl ASM_TSAN_SYMBOL_INTERCEPTOR(sigsetjmp)
+ASM_TYPE_FUNCTION(ASM_TSAN_SYMBOL_INTERCEPTOR(sigsetjmp))
+ASM_TSAN_SYMBOL_INTERCEPTOR(sigsetjmp):
   CFI_STARTPROC
   // save env parameter
   push %rdi
@@ -246,14 +270,19 @@
 #if defined(__FreeBSD__)
   lea 24(%rsp), %rdi
   mov %rdi, %rsi
-#else
+#elif defined(__APPLE__)
+  lea 32(%rsp), %rdi
+  mov %rdi, %rsi
+#elif defined(__linux__)
   lea 32(%rsp), %rdi
   mov %rdi, %rsi
   xor %fs:0x30, %rsi  // magic mangling of rsp (see libc setjmp)
   rol $0x11, %rsi
+#else
+# error "Unknown platform"
 #endif
   // call tsan interceptor
-  call __tsan_setjmp
+  call ASM_TSAN_SYMBOL(__tsan_setjmp)
   // unalign stack frame
   add $8, %rsp
   CFI_ADJUST_CFA_OFFSET(-8)
@@ -267,15 +296,20 @@
   CFI_RESTORE(%rdi)
   // tail jump to libc sigsetjmp
   movl $0, %eax
+#if !defined(__APPLE__)
   movq _ZN14__interception14real_sigsetjmpE@GOTPCREL(%rip), %rdx
   jmp *(%rdx)
+#else
+  jmp ASM_TSAN_SYMBOL(setjmp)
+#endif
   CFI_ENDPROC
-.size sigsetjmp, .-sigsetjmp
+ASM_SIZE(ASM_TSAN_SYMBOL_INTERCEPTOR(sigsetjmp))
 
+#if !defined(__APPLE__)
 .comm _ZN14__interception16real___sigsetjmpE,8,8
-.globl __sigsetjmp
-.type __sigsetjmp, @function
-__sigsetjmp:
+.globl ASM_TSAN_SYMBOL_INTERCEPTOR(__sigsetjmp)
+ASM_TYPE_FUNCTION(ASM_TSAN_SYMBOL_INTERCEPTOR(__sigsetjmp))
+ASM_TSAN_SYMBOL_INTERCEPTOR(__sigsetjmp):
   CFI_STARTPROC
   // save env parameter
   push %rdi
@@ -299,7 +333,7 @@
   rol $0x11, %rsi
 #endif
   // call tsan interceptor
-  call __tsan_setjmp
+  call ASM_TSAN_SYMBOL(__tsan_setjmp)
   // unalign stack frame
   add $8, %rsp
   CFI_ADJUST_CFA_OFFSET(-8)
@@ -316,7 +350,8 @@
   movq _ZN14__interception16real___sigsetjmpE@GOTPCREL(%rip), %rdx
   jmp *(%rdx)
   CFI_ENDPROC
-.size __sigsetjmp, .-__sigsetjmp
+ASM_SIZE(ASM_TSAN_SYMBOL_INTERCEPTOR(__sigsetjmp))
+#endif  // !defined(__APPLE__)
 
 #if defined(__FreeBSD__) || defined(__linux__)
 /* We do not need executable stack.  */