contrib/compiler-rt/lib/builtins/os_version_check.c

   1 /* ===-- os_version_check.c - OS version checking  -------------------------===
   2  *
   3  *                     The LLVM Compiler Infrastructure
   4  *
   5  * This file is dual licensed under the MIT and the University of Illinois Open
   6  * Source Licenses. See LICENSE.TXT for details.
   7  *
   8  * ===----------------------------------------------------------------------===
   9  *
  10  * This file implements the function __isOSVersionAtLeast, used by
  11  * Objective-C's @available
  12  *
  13  * ===----------------------------------------------------------------------===
  14  */
  15
  16 #ifdef __APPLE__
  17
  18 #include <TargetConditionals.h>
  19 #include <dispatch/dispatch.h>
  20 #include <dlfcn.h>
  21 #include <stdint.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 /* These three variables hold the host's OS version. */
  27 static int32_t GlobalMajor, GlobalMinor, GlobalSubminor;
  28 static dispatch_once_t DispatchOnceCounter;
  29
  30 /* We can't include <CoreFoundation/CoreFoundation.h> directly from here, so
  31  * just forward declare everything that we need from it. */
  32
  33 typedef const void *CFDataRef, *CFAllocatorRef, *CFPropertyListRef,
  34                    *CFStringRef, *CFDictionaryRef, *CFTypeRef, *CFErrorRef;
  35
  36 #if __LLP64__
  37 typedef unsigned long long CFTypeID;
  38 typedef unsigned long long CFOptionFlags;
  39 typedef signed long long CFIndex;
  40 #else
  41 typedef unsigned long CFTypeID;
  42 typedef unsigned long CFOptionFlags;
  43 typedef signed long CFIndex;
  44 #endif
  45
  46 typedef unsigned char UInt8;
  47 typedef _Bool Boolean;
  48 typedef CFIndex CFPropertyListFormat;
  49 typedef uint32_t CFStringEncoding;
  50
  51 /* kCFStringEncodingASCII analog. */
  52 #define CF_STRING_ENCODING_ASCII 0x0600
  53 /* kCFStringEncodingUTF8 analog. */
  54 #define CF_STRING_ENCODING_UTF8 0x08000100
  55 #define CF_PROPERTY_LIST_IMMUTABLE 0
  56
  57 typedef CFDataRef (*CFDataCreateWithBytesNoCopyFuncTy)(CFAllocatorRef,
  58                                                        const UInt8 *, CFIndex,
  59                                                        CFAllocatorRef);
  60 typedef CFPropertyListRef (*CFPropertyListCreateWithDataFuncTy)(
  61     CFAllocatorRef, CFDataRef, CFOptionFlags, CFPropertyListFormat *,
  62     CFErrorRef *);
  63 typedef CFPropertyListRef (*CFPropertyListCreateFromXMLDataFuncTy)(
  64     CFAllocatorRef, CFDataRef, CFOptionFlags, CFStringRef *);
  65 typedef CFStringRef (*CFStringCreateWithCStringNoCopyFuncTy)(CFAllocatorRef,
  66                                                              const char *,
  67                                                              CFStringEncoding,
  68                                                              CFAllocatorRef);
  69 typedef const void *(*CFDictionaryGetValueFuncTy)(CFDictionaryRef,
  70                                                   const void *);
  71 typedef CFTypeID (*CFGetTypeIDFuncTy)(CFTypeRef);
  72 typedef CFTypeID (*CFStringGetTypeIDFuncTy)(void);
  73 typedef Boolean (*CFStringGetCStringFuncTy)(CFStringRef, char *, CFIndex,
  74                                             CFStringEncoding);
  75 typedef void (*CFReleaseFuncTy)(CFTypeRef);
  76
  77 /* Find and parse the SystemVersion.plist file. */
  78 static void parseSystemVersionPList(void *Unused) {
  79   (void)Unused;
  80   /* Load CoreFoundation dynamically */
  81   const void *NullAllocator = dlsym(RTLD_DEFAULT, "kCFAllocatorNull");
  82   if (!NullAllocator)
  83     return;
  84   const CFAllocatorRef AllocatorNull = *(const CFAllocatorRef *)NullAllocator;
  85   CFDataCreateWithBytesNoCopyFuncTy CFDataCreateWithBytesNoCopyFunc =
  86       (CFDataCreateWithBytesNoCopyFuncTy)dlsym(RTLD_DEFAULT,
  87                                                "CFDataCreateWithBytesNoCopy");
  88   if (!CFDataCreateWithBytesNoCopyFunc)
  89     return;
  90   CFPropertyListCreateWithDataFuncTy CFPropertyListCreateWithDataFunc =
  91       (CFPropertyListCreateWithDataFuncTy)dlsym(
  92           RTLD_DEFAULT, "CFPropertyListCreateWithData");
  93 /* CFPropertyListCreateWithData was introduced only in macOS 10.6+, so it
  94  * will be NULL on earlier OS versions. */
  95 #pragma clang diagnostic push
  96 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
  97   CFPropertyListCreateFromXMLDataFuncTy CFPropertyListCreateFromXMLDataFunc =
  98       (CFPropertyListCreateFromXMLDataFuncTy)dlsym(
  99           RTLD_DEFAULT, "CFPropertyListCreateFromXMLData");
 100 #pragma clang diagnostic pop
 101   /* CFPropertyListCreateFromXMLDataFunc is deprecated in macOS 10.10, so it
 102    * might be NULL in future OS versions. */
 103   if (!CFPropertyListCreateWithDataFunc && !CFPropertyListCreateFromXMLDataFunc)
 104     return;
 105   CFStringCreateWithCStringNoCopyFuncTy CFStringCreateWithCStringNoCopyFunc =
 106       (CFStringCreateWithCStringNoCopyFuncTy)dlsym(
 107           RTLD_DEFAULT, "CFStringCreateWithCStringNoCopy");
 108   if (!CFStringCreateWithCStringNoCopyFunc)
 109     return;
 110   CFDictionaryGetValueFuncTy CFDictionaryGetValueFunc =
 111       (CFDictionaryGetValueFuncTy)dlsym(RTLD_DEFAULT, "CFDictionaryGetValue");
 112   if (!CFDictionaryGetValueFunc)
 113     return;
 114   CFGetTypeIDFuncTy CFGetTypeIDFunc =
 115       (CFGetTypeIDFuncTy)dlsym(RTLD_DEFAULT, "CFGetTypeID");
 116   if (!CFGetTypeIDFunc)
 117     return;
 118   CFStringGetTypeIDFuncTy CFStringGetTypeIDFunc =
 119       (CFStringGetTypeIDFuncTy)dlsym(RTLD_DEFAULT, "CFStringGetTypeID");
 120   if (!CFStringGetTypeIDFunc)
 121     return;
 122   CFStringGetCStringFuncTy CFStringGetCStringFunc =
 123       (CFStringGetCStringFuncTy)dlsym(RTLD_DEFAULT, "CFStringGetCString");
 124   if (!CFStringGetCStringFunc)
 125     return;
 126   CFReleaseFuncTy CFReleaseFunc =
 127       (CFReleaseFuncTy)dlsym(RTLD_DEFAULT, "CFRelease");
 128   if (!CFReleaseFunc)
 129     return;
 130
 131   char *PListPath = "/System/Library/CoreServices/SystemVersion.plist";
 132
 133 #if TARGET_OS_SIMULATOR
 134   char *PListPathPrefix = getenv("IPHONE_SIMULATOR_ROOT");
 135   if (!PListPathPrefix)
 136     return;
 137   char FullPath[strlen(PListPathPrefix) + strlen(PListPath) + 1];
 138   strcpy(FullPath, PListPathPrefix);
 139   strcat(FullPath, PListPath);
 140   PListPath = FullPath;
 141 #endif
 142   FILE *PropertyList = fopen(PListPath, "r");
 143   if (!PropertyList)
 144     return;
 145
 146   /* Dynamically allocated stuff. */
 147   CFDictionaryRef PListRef = NULL;
 148   CFDataRef FileContentsRef = NULL;
 149   UInt8 *PListBuf = NULL;
 150
 151   fseek(PropertyList, 0, SEEK_END);
 152   long PListFileSize = ftell(PropertyList);
 153   if (PListFileSize < 0)
 154     goto Fail;
 155   rewind(PropertyList);
 156
 157   PListBuf = malloc((size_t)PListFileSize);
 158   if (!PListBuf)
 159     goto Fail;
 160
 161   size_t NumRead = fread(PListBuf, 1, (size_t)PListFileSize, PropertyList);
 162   if (NumRead != (size_t)PListFileSize)
 163     goto Fail;
 164
 165   /* Get the file buffer into CF's format. We pass in a null allocator here *
 166    * because we free PListBuf ourselves */
 167   FileContentsRef = (*CFDataCreateWithBytesNoCopyFunc)(
 168       NULL, PListBuf, (CFIndex)NumRead, AllocatorNull);
 169   if (!FileContentsRef)
 170     goto Fail;
 171
 172   if (CFPropertyListCreateWithDataFunc)
 173     PListRef = (*CFPropertyListCreateWithDataFunc)(
 174         NULL, FileContentsRef, CF_PROPERTY_LIST_IMMUTABLE, NULL, NULL);
 175   else
 176     PListRef = (*CFPropertyListCreateFromXMLDataFunc)(
 177         NULL, FileContentsRef, CF_PROPERTY_LIST_IMMUTABLE, NULL);
 178   if (!PListRef)
 179     goto Fail;
 180
 181   CFStringRef ProductVersion = (*CFStringCreateWithCStringNoCopyFunc)(
 182       NULL, "ProductVersion", CF_STRING_ENCODING_ASCII, AllocatorNull);
 183   if (!ProductVersion)
 184     goto Fail;
 185   CFTypeRef OpaqueValue = (*CFDictionaryGetValueFunc)(PListRef, ProductVersion);
 186   (*CFReleaseFunc)(ProductVersion);
 187   if (!OpaqueValue ||
 188       (*CFGetTypeIDFunc)(OpaqueValue) != (*CFStringGetTypeIDFunc)())
 189     goto Fail;
 190
 191   char VersionStr[32];
 192   if (!(*CFStringGetCStringFunc)((CFStringRef)OpaqueValue, VersionStr,
 193                                  sizeof(VersionStr), CF_STRING_ENCODING_UTF8))
 194     goto Fail;
 195   sscanf(VersionStr, "%d.%d.%d", &GlobalMajor, &GlobalMinor, &GlobalSubminor);
 196
 197 Fail:
 198   if (PListRef)
 199     (*CFReleaseFunc)(PListRef);
 200   if (FileContentsRef)
 201     (*CFReleaseFunc)(FileContentsRef);
 202   free(PListBuf);
 203   fclose(PropertyList);
 204 }
 205
 206 int32_t __isOSVersionAtLeast(int32_t Major, int32_t Minor, int32_t Subminor) {
 207   /* Populate the global version variables, if they haven't already. */
 208   dispatch_once_f(&DispatchOnceCounter, NULL, parseSystemVersionPList);
 209
 210   if (Major < GlobalMajor)
 211     return 1;
 212   if (Major > GlobalMajor)
 213     return 0;
 214   if (Minor < GlobalMinor)
 215     return 1;
 216   if (Minor > GlobalMinor)
 217     return 0;
 218   return Subminor <= GlobalSubminor;
 219 }
 220
 221 #else
 222
 223 /* Silence an empty translation unit warning. */
 224 typedef int unused;
 225
 226 #endif