+ 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)
+{
+ 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;
+ }
+ }
+ #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());