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