]> git.saurik.com Git - apple/dyld.git/blobdiff - src/dyldAPIsInLibSystem.cpp
dyld-360.22.tar.gz
[apple/dyld.git] / src / dyldAPIsInLibSystem.cpp
index 67f4eb77f3d80d2b2714da3da19e1b138eeeddb0..d1e48f51f6461974ea8c9f6cb26c2fa70aeb9925 100644 (file)
@@ -1,6 +1,6 @@
 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
  *
- * Copyright (c) 2004-2005 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2004-2012 Apple Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
 
 #include <stddef.h>
 #include <string.h>
+#include <malloc/malloc.h>
+#include <sys/mman.h>
+
 #include <crt_externs.h>
+#include <Availability.h>
+#include <vproc_priv.h>
 
 #include "mach-o/dyld.h"
 #include "mach-o/dyld_priv.h"
 
+#include "ImageLoader.h"
 #include "dyldLock.h"
+#include "start_glue.h"
+
+extern "C" int  __cxa_atexit(void (*func)(void *), void *arg, void *dso);
+extern "C" void __cxa_finalize(const void *dso);
+extern "C" void __cxa_finalize_ranges(const struct __cxa_range_t ranges[], int count);
+
+
+#ifndef LC_VERSION_MIN_MACOSX
+       #define LC_VERSION_MIN_MACOSX 0x24
+       struct version_min_command {
+               uint32_t        cmd;            /* LC_VERSION_MIN_MACOSX or
+                                          LC_VERSION_MIN_IPHONEOS  */
+               uint32_t        cmdsize;        /* sizeof(struct min_version_command) */
+               uint32_t        version;        /* X.Y.Z is encoded in nibbles xxxx.yy.zz */
+               uint32_t        sdk;            /* X.Y.Z is encoded in nibbles xxxx.yy.zz */
+       };
+#endif
+
+#ifndef LC_VERSION_MIN_IPHONEOS
+       #define LC_VERSION_MIN_IPHONEOS 0x25
+#endif
+
+#ifndef LC_VERSION_MIN_TVOS
+       #define LC_VERSION_MIN_TVOS 0x2F
+#endif
+
+#ifndef LC_VERSION_MIN_WATCHOS
+       #define LC_VERSION_MIN_WATCHOS 0x30
+#endif
+
+
+#ifndef LC_LOAD_UPWARD_DYLIB
+       #define LC_LOAD_UPWARD_DYLIB (0x23|LC_REQ_DYLD) /* load of dylib whose initializers run later */
+#endif
+
+
+// deprecated APIs are still availble on Mac OS X, but not on iPhone OS
+#if __IPHONE_OS_VERSION_MIN_REQUIRED   
+       #define DEPRECATED_APIS_SUPPORTED 0
+#else
+       #define DEPRECATED_APIS_SUPPORTED 1
+#endif
 
 /*
  * names_match() takes an install_name from an LC_LOAD_DYLIB command and a
 static
 bool
 names_match(
-char *install_name,
+const char *install_name,
 const char* libraryName)
 {
-    char *basename;
+    const char *basename;
     unsigned long n;
 
        /*
@@ -64,7 +112,7 @@ const char* libraryName)
         * of the -framework cases.
         */
        if(strcmp(basename, libraryName) == 0)
-           return(TRUE);
+           return true;
 
        /*
         * Now check the base name for "lib" if so proceed to check for the
@@ -74,36 +122,39 @@ const char* libraryName)
            n = strlen(libraryName);
            if(strncmp(basename+3, libraryName, n) == 0){
                if(strncmp(basename+3+n, ".dylib", 6) == 0)
-                   return(TRUE);
+                   return true;
                if(basename[3+n] == '.' &&
                   basename[3+n+1] != '\0' &&
                   strncmp(basename+3+n+2, ".dylib", 6) == 0)
-                   return(TRUE);
+                   return true;
            }
        }
-       return(FALSE);
+       return false;
 }
 
+#if DEPRECATED_APIS_SUPPORTED
+
 void NSInstallLinkEditErrorHandlers(
 const NSLinkEditErrorHandlers* handlers)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
-    static void (*p)(
-       void     (*undefined)(const char* symbol_name),
-       NSModule (*multiple)(NSSymbol s, NSModule old, NSModule newhandler),
-       void     (*linkEdit)(NSLinkEditErrors c, int errorNumber,
-                    const char* fileName, const char* errorString)) = NULL;
+       DYLD_LOCK_THIS_BLOCK;
+       typedef void (*ucallback_t)(const char* symbol_name);
+       typedef NSModule (*mcallback_t)(NSSymbol s, NSModule old, NSModule newhandler);
+       typedef void (*lcallback_t)(NSLinkEditErrors c, int errorNumber,
+                                                               const char* fileName, const char* errorString);
+       static void (*p)(ucallback_t undefined, mcallback_t multiple, lcallback_t linkEdit) = NULL;
 
        if(p == NULL)
            _dyld_func_lookup("__dyld_install_handlers", (void**)&p);
-       p(handlers->undefined, handlers->multiple, handlers->linkEdit);
+       mcallback_t m = handlers->multiple;
+       p(handlers->undefined, m, handlers->linkEdit);
 }
 
 const char* 
 NSNameOfModule(
 NSModule module)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static const char*  (*p)(NSModule module) = NULL;
 
        if(p == NULL)
@@ -115,7 +166,7 @@ const char*
 NSLibraryNameForModule(
 NSModule module)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static const char*  (*p)(NSModule module) = NULL;
 
        if(p == NULL)
@@ -127,7 +178,7 @@ bool
 NSIsSymbolNameDefined(
 const char* symbolName)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(const char* symbolName) = NULL;
 
        if(p == NULL)
@@ -140,7 +191,7 @@ NSIsSymbolNameDefinedWithHint(
 const char* symbolName,
 const char* libraryNameHint)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(const char* symbolName,
                          const char* libraryNameHint) = NULL;
 
@@ -154,7 +205,7 @@ NSIsSymbolNameDefinedInImage(
 const struct mach_header *image,
 const char* symbolName)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(const struct mach_header *image,
                          const char* symbolName) = NULL;
 
@@ -167,7 +218,7 @@ NSSymbol
 NSLookupAndBindSymbol(
 const char* symbolName)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static NSSymbol (*p)(const char* symbolName) = NULL;
 
        if(p == NULL)
@@ -180,7 +231,7 @@ NSLookupAndBindSymbolWithHint(
 const char* symbolName,
 const char* libraryNameHint)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static NSSymbol (*p)(const char* symbolName,
                         const char* libraryNameHint) = NULL;
 
@@ -194,7 +245,7 @@ NSLookupSymbolInModule(
 NSModule module,
 const char* symbolName)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static NSSymbol (*p)(NSModule module, const char* symbolName) = NULL;
 
        if(p == NULL)
@@ -208,7 +259,7 @@ const struct mach_header *image,
 const char* symbolName,
 uint32_t options)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
    static NSSymbol (*p)(const struct mach_header *image,
                         const char* symbolName,
                         uint32_t options) = NULL;
@@ -222,7 +273,7 @@ const char*
 NSNameOfSymbol(
 NSSymbol symbol)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static char * (*p)(NSSymbol symbol) = NULL;
 
        if(p == NULL)
@@ -234,7 +285,7 @@ void *
 NSAddressOfSymbol(
 NSSymbol symbol)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void * (*p)(NSSymbol symbol) = NULL;
 
        if(p == NULL)
@@ -246,7 +297,7 @@ NSModule
 NSModuleForSymbol(
 NSSymbol symbol)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static NSModule (*p)(NSSymbol symbol) = NULL;
 
        if(p == NULL)
@@ -258,7 +309,7 @@ bool
 NSAddLibrary(
 const char* pathName)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(const char* pathName) = NULL;
 
        if(p == NULL)
@@ -270,7 +321,7 @@ bool
 NSAddLibraryWithSearching(
 const char* pathName)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(const char* pathName) = NULL;
 
        if(p == NULL)
@@ -283,7 +334,7 @@ NSAddImage(
 const char* image_name,
 uint32_t options)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static const struct mach_header * (*p)(const char* image_name,
                                           uint32_t options) = NULL;
 
@@ -291,6 +342,7 @@ uint32_t options)
            _dyld_func_lookup("__dyld_NSAddImage", (void**)&p);
        return(p(image_name, options));
 }
+#endif // DEPRECATED_APIS_SUPPORTED
 
 /*
  * This routine returns the current version of the named shared library the
@@ -303,41 +355,35 @@ uint32_t options)
  * and not a list of current versions that dependent libraries and bundles the
  * program is using were built with.
  */
-int32_t
-NSVersionOfLinkTimeLibrary(
-const char* libraryName)
+int32_t NSVersionOfLinkTimeLibrary(const char* libraryName)
 {
-    unsigned long i;
-    struct load_command *load_commands, *lc;
-    struct dylib_command *dl;
-    char *install_name;
-#ifndef __OPENSTEP__
-    static struct mach_header *mh = NULL;
-       if(mh == NULL)
+       // Lazily call _NSGetMachExecuteHeader() and cache result
+#if __LP64__
+    static mach_header_64* mh = NULL;
+#else
+    static mach_header* mh = NULL;
+#endif
+       if ( mh == NULL )
            mh = _NSGetMachExecuteHeader();
-#else /* defined(__OPENSTEP__) */
-#ifdef __DYNAMIC__
-    static struct mach_header *mh = NULL;
-       if(mh == NULL)
-           _dyld_lookup_and_bind("__mh_execute_header", &mh, NULL);
+#if __LP64__
+       const load_command* lc = (load_command*)((char*)mh + sizeof(mach_header_64));
 #else
-    struct mach_header *mh;
-       mh = (struct mach_header *)&_mh_execute_header;
+       const load_command* lc = (load_command*)((char*)mh + sizeof(mach_header));
 #endif
-#endif /* __OPENSTEP__ */
-       load_commands = (struct load_command *)
-                       ((char *)mh + sizeof(struct mach_header));
-       lc = load_commands;
-       for(i = 0; i < mh->ncmds; i++){
-           if(lc->cmd == LC_LOAD_DYLIB){
-               dl = (struct dylib_command *)lc;
-               install_name = (char *)dl + dl->dylib.name.offset;
-               if(names_match(install_name, libraryName) == TRUE)
-                   return(dl->dylib.current_version);
-           }
-           lc = (struct load_command *)((char *)lc + lc->cmdsize);
+       for(uint32_t i = 0; i < mh->ncmds; i++){
+               switch ( lc->cmd ) { 
+                       case LC_LOAD_DYLIB:
+                       case LC_LOAD_WEAK_DYLIB:
+                       case LC_LOAD_UPWARD_DYLIB:
+                               const dylib_command* dl = (dylib_command *)lc;
+                               const char* install_name = (char*)dl + dl->dylib.name.offset;
+                               if ( names_match(install_name, libraryName) )
+                                       return dl->dylib.current_version;
+                               break;
+               }
+           lc = (load_command*)((char*)lc + lc->cmdsize);
        }
-       return(-1);
+       return (-1);
 }
 
 /*
@@ -347,37 +393,305 @@ const char* libraryName)
  * it would be "x" and with -framework Foo it would be "Foo").  If the program
  * is not using the specified library it returns -1.
  */
-int32_t
-NSVersionOfRunTimeLibrary(
-const char* libraryName)
+int32_t NSVersionOfRunTimeLibrary(const char* libraryName)
+{
+       uint32_t n = _dyld_image_count();
+       for(uint32_t i = 0; i < n; i++){
+           const mach_header* mh = _dyld_get_image_header(i);
+               if ( mh == NULL )
+                       continue;
+           if ( mh->filetype != MH_DYLIB )
+                       continue;
+#if __LP64__
+           const load_command* lc = (load_command*)((char*)mh + sizeof(mach_header_64));
+#else
+           const load_command* lc = (load_command*)((char*)mh + sizeof(mach_header));
+#endif
+           for(uint32_t j = 0; j < mh->ncmds; j++){
+                       if ( lc->cmd == LC_ID_DYLIB ) {
+                               const dylib_command* dl = (dylib_command*)lc;
+                               const char* install_name = (char *)dl + dl->dylib.name.offset;
+                               if ( names_match(install_name, libraryName) )
+                                       return dl->dylib.current_version;
+                       }
+                       lc = (load_command*)((char*)lc + lc->cmdsize);
+           }
+       }
+       return (-1);
+}
+
+
+#define PACKED_VERSION(major, minor, tiny) ((((major) & 0xffff) << 16) | (((minor) & 0xff) << 8) | ((tiny) & 0xff))
+
+
+static bool getVersionLoadCommandInfo(const mach_header* mh, uint32_t* loadCommand, uint32_t* minOS, uint32_t* sdk)
 {
-    unsigned long i, j, n;
-    char *install_name;
-    struct load_command *load_commands, *lc;
-    struct dylib_command *dl;
-    const struct mach_header *mh;
-
-       n = _dyld_image_count();
-       for(i = 0; i < n; i++){
-           mh = _dyld_get_image_header(i);
-           if(mh->filetype != MH_DYLIB)
-               continue;
-           load_commands = (struct load_command *)
-                           ((char *)mh + sizeof(struct mach_header));
-           lc = load_commands;
-           for(j = 0; j < mh->ncmds; j++){
-               if(lc->cmd == LC_ID_DYLIB){
-                   dl = (struct dylib_command *)lc;
-                   install_name = (char *)dl + dl->dylib.name.offset;
-                   if(names_match(install_name, libraryName) == TRUE)
-                       return(dl->dylib.current_version);
+       const load_command* startCmds = NULL;
+       if ( mh->magic == MH_MAGIC_64 )
+               startCmds = (load_command*)((char *)mh + sizeof(mach_header_64));
+       else if ( mh->magic == MH_MAGIC )
+               startCmds = (load_command*)((char *)mh + sizeof(mach_header));
+       else
+               return false;  // not a mach-o file, or wrong endianness
+               
+       const load_command* const cmdsEnd = (load_command*)((char*)startCmds + mh->sizeofcmds);
+       const load_command* cmd = startCmds;
+       for(uint32_t i = 0; i < mh->ncmds; ++i) {
+           const load_command* nextCmd = (load_command*)((char *)cmd + cmd->cmdsize);
+               if ( (cmd->cmdsize < 8) || (nextCmd > cmdsEnd) || (nextCmd < startCmds)) {
+                       return 0;
+               }
+               const version_min_command* versCmd;
+               switch ( cmd->cmd ) {
+                       case LC_VERSION_MIN_IPHONEOS:
+                       case LC_VERSION_MIN_MACOSX:
+                       case LC_VERSION_MIN_TVOS:
+                       case LC_VERSION_MIN_WATCHOS:
+                               versCmd = (version_min_command*)cmd;
+                               *loadCommand = versCmd->cmd;
+                               *minOS = versCmd->version;
+                               *sdk = versCmd->sdk;
+                               return true;
+               }
+               cmd = nextCmd;
+       }
+       return false;
+}
+
+#if !__WATCH_OS_VERSION_MIN_REQUIRED && !__TV_OS_VERSION_MIN_REQUIRED
+static uint32_t deriveSDKVersFromDylibs(const mach_header* mh)
+{
+       const load_command* startCmds = NULL;
+       if ( mh->magic == MH_MAGIC_64 )
+               startCmds = (load_command*)((char *)mh + sizeof(mach_header_64));
+       else if ( mh->magic == MH_MAGIC )
+               startCmds = (load_command*)((char *)mh + sizeof(mach_header));
+       else
+               return 0;  // not a mach-o file, or wrong endianness
+               
+       const load_command* const cmdsEnd = (load_command*)((char*)startCmds + mh->sizeofcmds);
+       const dylib_command* dylibCmd;
+       const load_command* cmd = startCmds;
+       const char* dylibName;
+  #if __IPHONE_OS_VERSION_MIN_REQUIRED
+       uint32_t foundationVers = 0;
+  #else
+       uint32_t libSystemVers = 0;
+  #endif
+       for(uint32_t i = 0; i < mh->ncmds; ++i) {
+           const load_command* nextCmd = (load_command*)((char *)cmd + cmd->cmdsize);
+               // <rdar://problem/14381579&16050962> sanity check size of command
+               if ( (cmd->cmdsize < 8) || (nextCmd > cmdsEnd) || (nextCmd < startCmds)) {
+                       return 0;
+               }
+               switch ( cmd->cmd ) {
+                       case LC_LOAD_DYLIB:
+                       case LC_LOAD_WEAK_DYLIB:
+                       case LC_LOAD_UPWARD_DYLIB:
+                               dylibCmd = (dylib_command*)cmd;
+                               // sanity check dylib command layout
+                               if ( dylibCmd->dylib.name.offset > cmd->cmdsize )
+                                       return 0;
+                               dylibName = (char*)dylibCmd + dylibCmd->dylib.name.offset;
+  #if __IPHONE_OS_VERSION_MIN_REQUIRED
+                               if ( strcmp(dylibName, "/System/Library/Frameworks/Foundation.framework/Foundation") == 0 )
+                                       foundationVers = dylibCmd->dylib.current_version;
+  #else
+                               if ( strcmp(dylibName, "/usr/lib/libSystem.B.dylib") == 0 )
+                                       libSystemVers = dylibCmd->dylib.current_version;
+  #endif
+                               break;
+               }
+               cmd = nextCmd;
+       }
+
+       struct DylibToOSMapping {
+               uint32_t dylibVersion;
+               uint32_t osVersion;
+       };
+       
+  #if __IPHONE_OS_VERSION_MIN_REQUIRED
+       static const DylibToOSMapping foundationMapping[] = {
+               { PACKED_VERSION(678,24,0), DYLD_IOS_VERSION_2_0 },
+               { PACKED_VERSION(678,26,0), DYLD_IOS_VERSION_2_1 },
+               { PACKED_VERSION(678,29,0), DYLD_IOS_VERSION_2_2 },
+               { PACKED_VERSION(678,47,0), DYLD_IOS_VERSION_3_0 },
+               { PACKED_VERSION(678,51,0), DYLD_IOS_VERSION_3_1 },
+               { PACKED_VERSION(678,60,0), DYLD_IOS_VERSION_3_2 },
+               { PACKED_VERSION(751,32,0), DYLD_IOS_VERSION_4_0 },
+               { PACKED_VERSION(751,37,0), DYLD_IOS_VERSION_4_1 },
+               { PACKED_VERSION(751,49,0), DYLD_IOS_VERSION_4_2 },
+               { PACKED_VERSION(751,58,0), DYLD_IOS_VERSION_4_3 },
+               { PACKED_VERSION(881,0,0),  DYLD_IOS_VERSION_5_0 },
+               { PACKED_VERSION(890,1,0),  DYLD_IOS_VERSION_5_1 },
+               { PACKED_VERSION(992,0,0),  DYLD_IOS_VERSION_6_0 },
+               { PACKED_VERSION(993,0,0),  DYLD_IOS_VERSION_6_1 },  
+               { PACKED_VERSION(1038,14,0),DYLD_IOS_VERSION_7_0 },
+               { PACKED_VERSION(0,0,0),    DYLD_IOS_VERSION_7_0 }
+               // We don't need to expand this table because all recent
+               // binaries have LC_VERSION_MIN_ load command.
+       };
+
+       if ( foundationVers != 0 ) {
+               uint32_t lastOsVersion = 0;
+               for (const DylibToOSMapping* p=foundationMapping; ; ++p) {
+                       if ( p->dylibVersion == 0 )
+                               return p->osVersion;
+                       if ( foundationVers < p->dylibVersion )
+                               return lastOsVersion;
+                       lastOsVersion = p->osVersion;
+               }
+       }
+
+  #else
+       // Note: versions are for the GM release.  The last entry should
+       // always be zero.  At the start of the next major version,
+       // a new last entry needs to be added and the previous zero
+       // updated to the GM dylib version.
+       static const DylibToOSMapping libSystemMapping[] = {
+               { PACKED_VERSION(88,1,3),   DYLD_MACOSX_VERSION_10_4 },
+               { PACKED_VERSION(111,0,0),  DYLD_MACOSX_VERSION_10_5 },
+               { PACKED_VERSION(123,0,0),  DYLD_MACOSX_VERSION_10_6 },
+               { PACKED_VERSION(159,0,0),  DYLD_MACOSX_VERSION_10_7 },
+               { PACKED_VERSION(169,3,0),  DYLD_MACOSX_VERSION_10_8 },
+               { PACKED_VERSION(1197,0,0), DYLD_MACOSX_VERSION_10_9 },
+               { PACKED_VERSION(0,0,0),    DYLD_MACOSX_VERSION_10_9 }
+               // We don't need to expand this table because all recent
+               // binaries have LC_VERSION_MIN_ load command.
+       };
+
+       if ( libSystemVers != 0 ) {
+               uint32_t lastOsVersion = 0;
+               for (const DylibToOSMapping* p=libSystemMapping; ; ++p) {
+                       if ( p->dylibVersion == 0 )
+                               return p->osVersion;
+                       if ( libSystemVers < p->dylibVersion )
+                               return lastOsVersion;
+                       lastOsVersion = p->osVersion;
                }
-               lc = (struct load_command *)((char *)lc + lc->cmdsize);
-           }
        }
-       return(-1);
+  #endif
+  return 0;
 }
+#endif
+
 
+#if __WATCH_OS_VERSION_MIN_REQUIRED
+static uint32_t watchVersToIOSVers(uint32_t vers)
+{
+       return vers + 0x00070000;
+}
+
+uint32_t dyld_get_program_sdk_watch_os_version()
+{
+       const mach_header* mh = (mach_header*)_NSGetMachExecuteHeader();
+       uint32_t loadCommand;
+       uint32_t minOS;
+       uint32_t sdk;
+
+       if ( getVersionLoadCommandInfo(mh, &loadCommand, &minOS, &sdk) ) {
+               if ( loadCommand == LC_VERSION_MIN_WATCHOS )
+                               return sdk;
+       }
+       return 0;
+}
+#endif
+
+/*
+ * Returns the sdk version (encode as nibble XXXX.YY.ZZ) the
+ * specified binary was built against.
+ *
+ * First looks for LC_VERSION_MIN_* in binary and if sdk field is 
+ * not zero, return that value.
+ * Otherwise, looks for the libSystem.B.dylib the binary linked
+ * against and uses a table to convert that to an sdk version.
+ */
+uint32_t dyld_get_sdk_version(const mach_header* mh)
+{
+       uint32_t loadCommand;
+       uint32_t minOS;
+       uint32_t sdk;
+
+       if ( getVersionLoadCommandInfo(mh, &loadCommand, &minOS, &sdk) ) {
+               switch (loadCommand) {
+#if __WATCH_OS_VERSION_MIN_REQUIRED
+                       case LC_VERSION_MIN_WATCHOS:
+                               // new binary. sdk version looks like "2.0" but API wants "9.0"
+                               return watchVersToIOSVers(sdk);
+                       case LC_VERSION_MIN_IPHONEOS:
+                               // old binary. sdk matches API semantics so can return directly.
+                               return sdk;
+#elif __TV_OS_VERSION_MIN_REQUIRED
+                       case LC_VERSION_MIN_TVOS:
+                       case LC_VERSION_MIN_IPHONEOS:
+                               return sdk;
+#elif __IPHONE_OS_VERSION_MIN_REQUIRED
+                       case LC_VERSION_MIN_IPHONEOS:
+                               if ( sdk != 0 ) // old binaries might not have SDK set
+                                       return sdk;
+                               break;
+#else
+                       case LC_VERSION_MIN_MACOSX:
+                               if ( sdk != 0 ) // old binaries might not have SDK set
+                                       return sdk;
+                               break;
+#endif
+               }
+       }
+
+#if __WATCH_OS_VERSION_MIN_REQUIRED ||__TV_OS_VERSION_MIN_REQUIRED
+       // All WatchOS and tv OS binaries should have version load command.
+       return 0;
+#else
+       // MacOSX and iOS have old binaries without version load commmand.
+       return deriveSDKVersFromDylibs(mh);
+#endif
+}
+
+uint32_t dyld_get_program_sdk_version()
+{
+       return dyld_get_sdk_version((mach_header*)_NSGetMachExecuteHeader());
+}
+
+uint32_t dyld_get_min_os_version(const struct mach_header* mh)
+{
+       uint32_t loadCommand;
+       uint32_t minOS;
+       uint32_t sdk;
+
+       if ( getVersionLoadCommandInfo(mh, &loadCommand, &minOS, &sdk) ) {
+               switch (loadCommand) {
+#if __WATCH_OS_VERSION_MIN_REQUIRED
+                       case LC_VERSION_MIN_WATCHOS:
+                               // new binary. OS version looks like "2.0" but API wants "9.0"
+                               return watchVersToIOSVers(minOS);
+                       case LC_VERSION_MIN_IPHONEOS:
+                               // old binary. OS matches API semantics so can return directly.
+                               return minOS;
+#elif __TV_OS_VERSION_MIN_REQUIRED
+                       case LC_VERSION_MIN_TVOS:
+                       case LC_VERSION_MIN_IPHONEOS:
+                               return minOS;
+#elif __IPHONE_OS_VERSION_MIN_REQUIRED
+                       case LC_VERSION_MIN_IPHONEOS:
+                               return minOS;
+#else
+                       case LC_VERSION_MIN_MACOSX:
+                               return minOS;
+#endif
+               }
+       }
+       return 0;
+}
+
+
+uint32_t dyld_get_program_min_os_version()
+{
+       return dyld_get_min_os_version((mach_header*)_NSGetMachExecuteHeader());
+}
+
+
+#if DEPRECATED_APIS_SUPPORTED
 /*
  * NSCreateObjectFileImageFromFile() creates an NSObjectFileImage for the
  * specified file name if the file is a correct Mach-O file that can be loaded
@@ -390,7 +704,7 @@ NSCreateObjectFileImageFromFile(
 const char* pathName,
 NSObjectFileImage *objectFileImage)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static NSObjectFileImageReturnCode (*p)(const char*, NSObjectFileImage*) = NULL;
 
        if(p == NULL)
@@ -412,7 +726,7 @@ const void* address,
 size_t size, 
 NSObjectFileImage *objectFileImage)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static NSObjectFileImageReturnCode (*p)(const void*, size_t, NSObjectFileImage*) = NULL;
 
        if(p == NULL)
@@ -420,6 +734,7 @@ NSObjectFileImage *objectFileImage)
        return p(address, size, objectFileImage);
 }
 
+#if OBSOLETE_DYLD_API
 /*
  * NSCreateCoreFileImageFromFile() creates an NSObjectFileImage for the 
  * specified core file name if the file is a correct Mach-O core file.
@@ -431,19 +746,20 @@ NSCreateCoreFileImageFromFile(
 const char* pathName,
 NSObjectFileImage *objectFileImage)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static NSObjectFileImageReturnCode (*p)(const char*, NSObjectFileImage*) = NULL;
 
        if(p == NULL)
            _dyld_func_lookup("__dyld_NSCreateCoreFileImageFromFile", (void**)&p);
        return p(pathName, objectFileImage);
 }
+#endif
 
 bool
 NSDestroyObjectFileImage(
 NSObjectFileImage objectFileImage)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(NSObjectFileImage) = NULL;
 
        if(p == NULL)
@@ -458,7 +774,7 @@ NSObjectFileImage objectFileImage,
 const char* moduleName,
 uint32_t options)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static NSModule (*p)(NSObjectFileImage, const char*, unsigned long) = NULL;
 
        if(p == NULL)
@@ -468,31 +784,6 @@ uint32_t options)
 }
 
 
-/*
- * NSFindSectionAndOffsetInObjectFileImage() takes the specified imageOffset
- * into the specified ObjectFileImage and returns the segment/section name and
- * offset into that section of that imageOffset.  Returns FALSE if the
- * imageOffset is not in any section.  You can used the resulting sectionOffset
- * to index into the data returned by NSGetSectionDataInObjectFileImage.
- * 
- * SPI: currently only used by ZeroLink to detect +load methods
- */
-bool 
-NSFindSectionAndOffsetInObjectFileImage(
-NSObjectFileImage objectFileImage, 
-unsigned long imageOffset,
-const char** segmentName,      /* can be NULL */
-const char** sectionName,      /* can be NULL */
-unsigned long* sectionOffset)  /* can be NULL */
-{
-       DYLD_READER_LOCK_THIS_BLOCK;
-    static bool (*p)(NSObjectFileImage, unsigned long, const char**, const char**, unsigned long*) = NULL;
-
-       if(p == NULL)
-           _dyld_func_lookup("__dyld_NSFindSectionAndOffsetInObjectFileImage", (void**)&p);
-               
-       return p(objectFileImage, imageOffset, segmentName, sectionName, sectionOffset);
-}
 
 
 /*
@@ -503,7 +794,7 @@ uint32_t
 NSSymbolDefinitionCountInObjectFileImage(
 NSObjectFileImage objectFileImage)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static unsigned long (*p)(NSObjectFileImage) = NULL;
 
        if(p == NULL)
@@ -523,7 +814,7 @@ NSSymbolDefinitionNameInObjectFileImage(
 NSObjectFileImage objectFileImage,
 uint32_t ordinal)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static const char*  (*p)(NSObjectFileImage, uint32_t) = NULL;
 
        if(p == NULL)
@@ -540,7 +831,7 @@ uint32_t
 NSSymbolReferenceCountInObjectFileImage(
 NSObjectFileImage objectFileImage)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static unsigned long (*p)(NSObjectFileImage) = NULL;
 
        if(p == NULL)
@@ -561,7 +852,7 @@ NSObjectFileImage objectFileImage,
 uint32_t ordinal,
 bool *tentative_definition) /* can be NULL */
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static const char*  (*p)(NSObjectFileImage, uint32_t, bool*) = NULL;
 
        if(p == NULL)
@@ -579,7 +870,7 @@ NSIsSymbolDefinedInObjectFileImage(
 NSObjectFileImage objectFileImage,
 const char* symbolName)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(NSObjectFileImage, const char*) = NULL;
 
        if(p == NULL)
@@ -602,7 +893,7 @@ const char* segmentName,
 const char* sectionName,
 unsigned long *size) /* can be NULL */
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void* (*p)(NSObjectFileImage, const char*, const char*, unsigned long*) = NULL;
 
        if(p == NULL)
@@ -611,24 +902,6 @@ unsigned long *size) /* can be NULL */
        return p(objectFileImage, segmentName, sectionName, size);
 }
 
-/*
- * NSHasModInitObjectFileImage() returns TRUE if the NSObjectFileImage has any
- * module initialization sections and FALSE it it does not.
- *
- * SPI: currently only used by ZeroLink to detect C++ initializers
- */
-bool
-NSHasModInitObjectFileImage(
-NSObjectFileImage objectFileImage)
-{
-       DYLD_READER_LOCK_THIS_BLOCK;
-    static bool (*p)(NSObjectFileImage) = NULL;
-
-       if(p == NULL)
-           _dyld_func_lookup("__dyld_NSHasModInitObjectFileImage", (void**)&p);
-               
-       return p(objectFileImage);
-}
 
 void
 NSLinkEditError(
@@ -637,7 +910,7 @@ int *errorNumber,
 const char* *fileName,
 const char* *errorString)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void (*p)(NSLinkEditErrors *c,
                     int *errorNumber, 
                     const char* *fileName,
@@ -654,7 +927,7 @@ NSUnLinkModule(
 NSModule module, 
 uint32_t options)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(NSModule module, uint32_t options) = NULL;
 
        if(p == NULL)
@@ -663,6 +936,7 @@ uint32_t options)
        return p(module, options);
 }
 
+#if OBSOLETE_DYLD_API
 NSModule
 NSReplaceModule(
 NSModule moduleToReplace,
@@ -671,6 +945,10 @@ uint32_t options)
 {
        return(NULL);
 }
+#endif
+
+
+#endif // DEPRECATED_APIS_SUPPORTED
 
 /*
  *_NSGetExecutablePath copies the path of the executable into the buffer and
@@ -686,7 +964,7 @@ _NSGetExecutablePath(
 char *buf,
 uint32_t *bufsize)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static int (*p)(char *buf, uint32_t *bufsize) = NULL;
 
        if(p == NULL)
@@ -694,13 +972,14 @@ uint32_t *bufsize)
        return(p(buf, bufsize));
 }
 
+#if DEPRECATED_APIS_SUPPORTED
 void
 _dyld_lookup_and_bind(
 const char* symbol_name,
 void** address,
 NSModule* module)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void (*p)(const char*, void** , NSModule*) = NULL;
 
        if(p == NULL)
@@ -715,7 +994,7 @@ const char* library_name_hint,
 void** address,
 NSModule* module)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void (*p)(const char*, const char*, void**, NSModule*) = NULL;
 
        if(p == NULL)
@@ -723,19 +1002,21 @@ NSModule* module)
        p(symbol_name, library_name_hint, address, module);
 }
 
+#if OBSOLETE_DYLD_API
 void
 _dyld_lookup_and_bind_objc(
 const char* symbol_name,
 void** address,
 NSModule* module)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void (*p)(const char* , void**, NSModule*) = NULL;
 
        if(p == NULL)
            _dyld_func_lookup("__dyld_lookup_and_bind_objc", (void**)&p);
        p(symbol_name, address, module);
 }
+#endif
 
 void
 _dyld_lookup_and_bind_fully(
@@ -743,7 +1024,7 @@ const char* symbol_name,
 void** address,
 NSModule* module)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void (*p)(const char*, void**, NSModule*) = NULL;
 
        if(p == NULL)
@@ -755,13 +1036,14 @@ bool
 _dyld_bind_fully_image_containing_address(
 const void* address)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(const void*) = NULL;
 
        if(p == NULL)
            _dyld_func_lookup("__dyld_bind_fully_image_containing_address", (void**)&p);
        return p(address);
 }
+#endif // DEPRECATED_APIS_SUPPORTED
 
 
 /*
@@ -774,8 +1056,9 @@ void
 _dyld_register_func_for_add_image(
 void (*func)(const struct mach_header *mh, intptr_t vmaddr_slide))
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
-    static void (*p)(void (*func)(const struct mach_header *mh, intptr_t vmaddr_slide)) = NULL;
+       DYLD_LOCK_THIS_BLOCK;
+       typedef void (*callback_t)(const struct mach_header *mh, intptr_t vmaddr_slide);
+    static void (*p)(callback_t func) = NULL;
 
        if(p == NULL)
            _dyld_func_lookup("__dyld_register_func_for_add_image", (void**)&p);
@@ -791,14 +1074,16 @@ void
 _dyld_register_func_for_remove_image(
 void (*func)(const struct mach_header *mh, intptr_t vmaddr_slide))
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
-    static void (*p)(void (*func)(const struct mach_header *mh, intptr_t vmaddr_slide)) = NULL;
+       DYLD_LOCK_THIS_BLOCK;
+       typedef void (*callback_t)(const struct mach_header *mh, intptr_t vmaddr_slide);
+    static void (*p)(callback_t func) = NULL;
 
        if(p == NULL)
            _dyld_func_lookup("__dyld_register_func_for_remove_image", (void**)&p);
        p(func);
 }
 
+#if OBSOLETE_DYLD_API
 /*
  * _dyld_register_func_for_link_module registers the specified function to be
  * called when a module is bound into the program.  When this function is first
@@ -809,7 +1094,7 @@ void
 _dyld_register_func_for_link_module(
 void (*func)(NSModule module))
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void (*p)(void (*func)(NSModule module)) = NULL;
 
        if(p == NULL)
@@ -825,7 +1110,7 @@ void
 _dyld_register_func_for_unlink_module(
 void (*func)(NSModule module))
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void (*p)(void (*func)(NSModule module)) = NULL;
 
        if(p == NULL)
@@ -841,7 +1126,7 @@ void
 _dyld_register_func_for_replace_module(
 void (*func)(NSModule oldmodule, NSModule newmodule))
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void (*p)(void (*func)(NSModule oldmodule,
                                  NSModule newmodule)) = NULL;
 
@@ -862,7 +1147,7 @@ NSModule module,
 void **objc_module,
 unsigned long *size)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void (*p)(NSModule module,
                     void **objc_module,
                     unsigned long *size) = NULL;
@@ -878,45 +1163,39 @@ unsigned long *size)
  * to be bound.
  */
 void
-_dyld_bind_objc_module(
-const void* objc_module)
+_dyld_bind_objc_module(const void* objc_module)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void (*p)(const void *objc_module) = NULL;
 
        if(p == NULL)
            _dyld_func_lookup("__dyld_bind_objc_module", (void**)&p);
        p(objc_module);
 }
+#endif
 
-
-#if __DYNAMIC__
+#if DEPRECATED_APIS_SUPPORTED
 bool
-_dyld_present(
-void)
+_dyld_present(void)
 {
-       // hmmm, this code is in libSystem.dylib, which is loaded by dyld...
+       // this function exists for compatiblity only
        return true;
 }
 #endif
 
 uint32_t
-_dyld_image_count(
-void)
+_dyld_image_count(void)
 {
        DYLD_NO_LOCK_THIS_BLOCK;
-    static unsigned long (*p)(void) = NULL;
+    static uint32_t (*p)(void) = NULL;
 
-       if(_dyld_present() == 0)
-           return(0);
        if(p == NULL)
            _dyld_func_lookup("__dyld_image_count", (void**)&p);
        return(p());
 }
 
 const struct mach_header *
-_dyld_get_image_header(
-uint32_t image_index)
+_dyld_get_image_header(uint32_t image_index)
 {
        DYLD_NO_LOCK_THIS_BLOCK;
     static struct mach_header * (*p)(uint32_t image_index) = NULL;
@@ -927,8 +1206,7 @@ uint32_t image_index)
 }
 
 intptr_t
-_dyld_get_image_vmaddr_slide(
-uint32_t image_index)
+_dyld_get_image_vmaddr_slide(uint32_t image_index)
 {
        DYLD_NO_LOCK_THIS_BLOCK;
     static unsigned long (*p)(uint32_t image_index) = NULL;
@@ -939,8 +1217,7 @@ uint32_t image_index)
 }
 
 const char* 
-_dyld_get_image_name(
-uint32_t image_index)
+_dyld_get_image_name(uint32_t image_index)
 {
        DYLD_NO_LOCK_THIS_BLOCK;
     static const char*  (*p)(uint32_t image_index) = NULL;
@@ -950,11 +1227,22 @@ uint32_t image_index)
        return(p(image_index));
 }
 
+// SPI in Mac OS X 10.6
+intptr_t _dyld_get_image_slide(const struct mach_header* mh)
+{
+       DYLD_NO_LOCK_THIS_BLOCK;
+    static intptr_t (*p)(const struct mach_header*) = NULL;
+
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_get_image_slide", (void**)&p);
+       return(p(mh));
+}
+
+
 bool
-_dyld_image_containing_address(
-const void* address)
+_dyld_image_containing_address(const void* address)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(const void*) = NULL;
 
        if(p == NULL)
@@ -966,7 +1254,7 @@ const struct mach_header *
 _dyld_get_image_header_containing_address(
 const void* address)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static const struct mach_header * (*p)(const void*) = NULL;
 
        if(p == NULL)
@@ -974,21 +1262,11 @@ const void* address)
        return p(address);
 }
 
-void _dyld_moninit(
-void (*monaddition)(char *lowpc, char *highpc))
-{
-       DYLD_READER_LOCK_THIS_BLOCK;
-    static void (*p)(void (*monaddition)(char *lowpc, char *highpc)) = NULL;
 
-       if(p == NULL)
-           _dyld_func_lookup("__dyld_moninit", (void**)&p);
-       p(monaddition);
-}
-
-bool _dyld_launched_prebound(
-void)
+#if DEPRECATED_APIS_SUPPORTED
+bool _dyld_launched_prebound(void)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(void) = NULL;
 
        if(p == NULL)
@@ -996,16 +1274,16 @@ void)
        return(p());
 }
 
-bool _dyld_all_twolevel_modules_prebound(
-void)
+bool _dyld_all_twolevel_modules_prebound(void)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static bool (*p)(void) = NULL;
 
        if(p == NULL)
            _dyld_func_lookup("__dyld_all_twolevel_modules_prebound", (void**)&p);
        return(p());
 }
+#endif // DEPRECATED_APIS_SUPPORTED
 
 
 #include <dlfcn.h>
@@ -1013,27 +1291,36 @@ void)
 #include <pthread.h>
 #include <stdlib.h>
 #include <mach-o/dyld.h>
-#include "dyldLock.h"
-#include "dyldLibSystemThreadHelpers.h"
+#include <servers/bootstrap.h>
+#include "dyldLibSystemInterface.h"
+
 
 // pthread key used to access per-thread dlerror message
 static pthread_key_t dlerrorPerThreadKey;
+static bool dlerrorPerThreadKeyInitialized = false;
 
 // data kept per-thread
 struct dlerrorPerThreadData
 {
-       uint32_t        sizeAllocated;
+       size_t          sizeAllocated;
        char            message[1];
 };
 
 // function called by dyld to get buffer to store dlerror message
-static char* getPerThreadBufferFor_dlerror(uint32_t sizeRequired)
+static char* getPerThreadBufferFor_dlerror(size_t sizeRequired)
 {
-       const int size = (sizeRequired < 256) ? 256 : sizeRequired;
+       // ok to create key lazily because this function is called within dyld lock, so there is no race condition
+       if (!dlerrorPerThreadKeyInitialized ) {
+               // create key and tell pthread package to call free() on any data associated with key if thread dies
+               pthread_key_create(&dlerrorPerThreadKey, &free);
+               dlerrorPerThreadKeyInitialized = true;
+       }
+
+       const size_t size = (sizeRequired < 256) ? 256 : sizeRequired;
        dlerrorPerThreadData* data = (dlerrorPerThreadData*)pthread_getspecific(dlerrorPerThreadKey);
        if ( data == NULL ) {
                //int mallocSize = offsetof(dlerrorPerThreadData, message[size]);
-               const int mallocSize = sizeof(dlerrorPerThreadData)+size;
+               const size_t mallocSize = sizeof(dlerrorPerThreadData)+size;
                data = (dlerrorPerThreadData*)malloc(mallocSize);
                data->sizeAllocated = size;
                pthread_setspecific(dlerrorPerThreadKey, data);
@@ -1041,7 +1328,7 @@ static char* getPerThreadBufferFor_dlerror(uint32_t sizeRequired)
        else if ( data->sizeAllocated < sizeRequired ) {
                free(data);
                //int mallocSize = offsetof(dlerrorPerThreadData, message[size]);
-               const int mallocSize = sizeof(dlerrorPerThreadData)+size;
+               const size_t mallocSize = sizeof(dlerrorPerThreadData)+size;
                data = (dlerrorPerThreadData*)malloc(mallocSize);
                data->sizeAllocated = size;
                pthread_setspecific(dlerrorPerThreadKey, data);
@@ -1049,37 +1336,88 @@ static char* getPerThreadBufferFor_dlerror(uint32_t sizeRequired)
        return data->message;
 }
 
-// that table passed to dyld containing thread helpers
-static dyld::ThreadingHelpers sThreadHelpers = { 1, &lockForLazyBinding, &unlockForLazyBinding, &getPerThreadBufferFor_dlerror };
+// <rdar://problem/10595338> dlerror buffer leak
+// Only allocate buffer if an actual error message needs to be set
+static bool hasPerThreadBufferFor_dlerror()
+{
+       if (!dlerrorPerThreadKeyInitialized ) 
+               return false;
+               
+       return (pthread_getspecific(dlerrorPerThreadKey) != NULL);
+}
+
+// use non-lazy pointer to vproc_swap_integer so that lazy binding does not recurse
+typedef vproc_err_t (*vswapproc)(vproc_t vp, vproc_gsk_t key,int64_t *inval, int64_t *outval);
+static vswapproc swapProc = &vproc_swap_integer;
+
+static bool isLaunchdOwned() {
+       static bool first = true;
+       static bool result;
+       if ( first ) {
+               int64_t val = 0;
+               (*swapProc)(NULL, VPROC_GSK_IS_MANAGED, NULL, &val);
+               result = ( val != 0 );
+               first = false;
+       }
+       return result;
+}
+
+
+#if DYLD_SHARED_CACHE_SUPPORT
+static void shared_cache_missing()
+{
+       // leave until dyld's that might call this are rare
+}
+
+static void shared_cache_out_of_date()
+{
+       // leave until dyld's that might call this are rare
+}
+#endif // DYLD_SHARED_CACHE_SUPPORT
+
+
+// the table passed to dyld containing thread helpers
+static dyld::LibSystemHelpers sHelpers = { 13, &dyldGlobalLockAcquire, &dyldGlobalLockRelease,
+                                                                       &getPerThreadBufferFor_dlerror, &malloc, &free, &__cxa_atexit,
+                                               #if DYLD_SHARED_CACHE_SUPPORT
+                                                                       &shared_cache_missing, &shared_cache_out_of_date,
+                                               #else
+                                                                       NULL, NULL,
+                                               #endif
+                                                                       NULL, NULL,
+                                                                       &pthread_key_create, &pthread_setspecific,
+                                                                       &malloc_size,
+                                                                       &pthread_getspecific,
+                                                                       &__cxa_finalize,
+                                                                       address_of_start,
+                                                                       &hasPerThreadBufferFor_dlerror,
+                                                                       &isLaunchdOwned,
+                                                                       &vm_allocate,
+                                                                       &mmap,
+                                                                       &__cxa_finalize_ranges};
+
 
 //
 // during initialization of libSystem this routine will run
-// and call dyld, registering the threading helpers.
+// and call dyld, registering the helper functions.
 //
-//
-static int registerWithDyld()
-{
-    static void (*p)(dyld::ThreadingHelpers*) = NULL;
+extern "C" void tlv_initializer();
+extern "C" void _dyld_initializer();
+void _dyld_initializer()
+{      
+   void (*p)(dyld::LibSystemHelpers*);
 
-       // create key and tell pthread package to call free() on any data associated with key if thread dies
-       pthread_key_create(&dlerrorPerThreadKey, &free);
-       
-       if(p == NULL) 
-           _dyld_func_lookup("__dyld_register_thread_helpers", (void**)&p);
+       _dyld_func_lookup("__dyld_register_thread_helpers", (void**)&p);
        if(p != NULL)
-               p(&sThreadHelpers);
-       
-       return 0;
+               p(&sHelpers);
+               
+       tlv_initializer();
 }
 
-// should be able to use __attribute__((constructor)) on registerWithDyld, but compiler has bug (3679135)
-// instead use initialization of global to force it to run.
-static int hack = registerWithDyld();
-
 
 char* dlerror()
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static char* (*p)() = NULL;
 
        if(p == NULL)
@@ -1089,7 +1427,7 @@ char* dlerror()
 
 int dladdr(const void* addr, Dl_info* info)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static int (*p)(const void* , Dl_info*) = NULL;
 
        if(p == NULL)
@@ -1099,7 +1437,7 @@ int dladdr(const void* addr, Dl_info* info)
 
 int dlclose(void* handle)
 {
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static int (*p)(void* handle) = NULL;
 
        if(p == NULL)
@@ -1108,18 +1446,36 @@ int dlclose(void* handle)
 }
 
 void* dlopen(const char* path, int mode)
-{
-       DYLD_WRITER_LOCK_THIS_BLOCK;
+{      
+       // dlopen is special. locking is done inside dyld to allow initializer to run without lock
+       DYLD_NO_LOCK_THIS_BLOCK;
+       
     static void* (*p)(const char* path, int) = NULL;
 
        if(p == NULL)
            _dyld_func_lookup("__dyld_dlopen", (void**)&p);
-       return(p(path, mode));
+       void* result = p(path, mode);
+       // use asm block to prevent tail call optimization
+       // this is needed because dlopen uses __builtin_return_address() and depends on this glue being in the frame chain
+       // <rdar://problem/5313172 dlopen() looks too far up stack, can cause crash>
+       __asm__ volatile(""); 
+       
+       return result;
+}
+
+bool dlopen_preflight(const char* path)
+{
+       DYLD_LOCK_THIS_BLOCK;
+    static bool (*p)(const char* path) = NULL;
+
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_dlopen_preflight", (void**)&p);
+       return(p(path));
 }
 
 void* dlsym(void* handle, const char* symbol)
 {
-       DYLD_READER_LOCK_THIS_BLOCK;
+       DYLD_LOCK_THIS_BLOCK;
     static void* (*p)(void* handle, const char* symbol) = NULL;
 
        if(p == NULL)
@@ -1127,6 +1483,130 @@ void* dlsym(void* handle, const char* symbol)
        return(p(handle, symbol));
 }
 
+void dyld_register_image_state_change_handler(dyld_image_states state, 
+                                                                                       bool batch, dyld_image_state_change_handler handler)
+{
+       DYLD_LOCK_THIS_BLOCK;
+    static void* (*p)(dyld_image_states, bool, dyld_image_state_change_handler) = NULL;
+
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_dyld_register_image_state_change_handler", (void**)&p);
+       p(state, batch, handler);
+}
+
+
+const struct dyld_all_image_infos* _dyld_get_all_image_infos()
+{
+       DYLD_NO_LOCK_THIS_BLOCK;
+    static struct dyld_all_image_infos* (*p)() = NULL;
+
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_get_all_image_infos", (void**)&p);
+       return p();
+}
+
+#if SUPPORT_ZERO_COST_EXCEPTIONS
+bool _dyld_find_unwind_sections(void* addr, dyld_unwind_sections* info)
+{
+       DYLD_NO_LOCK_THIS_BLOCK;
+    static void* (*p)(void*, dyld_unwind_sections*) = NULL;
+
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_find_unwind_sections", (void**)&p);
+       return p(addr, info);
+}
+#endif
+
+
+#if __i386__ || __x86_64__ || __arm__ || __arm64__
+__attribute__((visibility("hidden"))) 
+void* _dyld_fast_stub_entry(void* loadercache, long lazyinfo)
+{
+       DYLD_NO_LOCK_THIS_BLOCK;
+    static void* (*p)(void*, long) = NULL;
+
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_fast_stub_entry", (void**)&p);
+       return p(loadercache, lazyinfo);
+}
+#endif
+
+
+const char* dyld_image_path_containing_address(const void* addr)
+{
+       DYLD_NO_LOCK_THIS_BLOCK;
+    static const char* (*p)(const void*) = NULL;
+
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_image_path_containing_address", (void**)&p);
+       return p(addr);
+}
+
+const struct mach_header* dyld_image_header_containing_address(const void* addr)
+{
+       DYLD_NO_LOCK_THIS_BLOCK;
+    static const mach_header* (*p)(const void*) = NULL;
+
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_get_image_header_containing_address", (void**)&p);
+       return p(addr);
+}
+
+
+bool dyld_shared_cache_some_image_overridden()
+{
+       DYLD_NO_LOCK_THIS_BLOCK;
+    static bool (*p)() = NULL;
+
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_shared_cache_some_image_overridden", (void**)&p);
+       return p();
+}
+
+
+bool dyld_process_is_restricted()
+{
+       DYLD_NO_LOCK_THIS_BLOCK;
+    static bool (*p)() = NULL;
+       
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_process_is_restricted", (void**)&p);
+       return p();
+}
+
+#if DYLD_SHARED_CACHE_SUPPORT
+const char* dyld_shared_cache_file_path()
+{
+       DYLD_NO_LOCK_THIS_BLOCK;
+    static const char* (*p)() = NULL;
+       
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_shared_cache_file_path", (void**)&p);
+       return p();
+}
+#endif
+
+void dyld_dynamic_interpose(const struct mach_header* mh, const struct dyld_interpose_tuple array[], size_t count)
+{
+       DYLD_LOCK_THIS_BLOCK;
+    static void (*p)(const struct mach_header* mh, const struct dyld_interpose_tuple array[], size_t count) = NULL;
+
+       if (p == NULL)
+           _dyld_func_lookup("__dyld_dynamic_interpose", (void**)&p);
+       p(mh, array, count);
+}
+
+
+// SPI called __fork
+void _dyld_fork_child()
+{
+       DYLD_NO_LOCK_THIS_BLOCK;
+    static void (*p)() = NULL;
+
+       if(p == NULL)
+           _dyld_func_lookup("__dyld_fork_child", (void**)&p);
+       return p();
+}