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

   1 //===-- os_version_check.c - OS version checking  -------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the function __isOSVersionAtLeast, used by
  10 // Objective-C's @available
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifdef __APPLE__
  15
  16 #include <TargetConditionals.h>
  17 #include <dispatch/dispatch.h>
  18 #include <dlfcn.h>
  19 #include <stdint.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23
  24 // These three variables hold the host's OS version.
  25 static int32_t GlobalMajor, GlobalMinor, GlobalSubminor;
  26 static dispatch_once_t DispatchOnceCounter;
  27
  28 // We can't include <CoreFoundation/CoreFoundation.h> directly from here, so
  29 // just forward declare everything that we need from it.
  30
  31 typedef const void *CFDataRef, *CFAllocatorRef, *CFPropertyListRef,
  32     *CFStringRef, *CFDictionaryRef, *CFTypeRef, *CFErrorRef;
  33
  34 #if __LLP64__
  35 typedef unsigned long long CFTypeID;
  36 typedef unsigned long long CFOptionFlags;
  37 typedef signed long long CFIndex;
  38 #else
  39 typedef unsigned long CFTypeID;
  40 typedef unsigned long CFOptionFlags;
  41 typedef signed long CFIndex;
  42 #endif
  43
  44 typedef unsigned char UInt8;
  45 typedef _Bool Boolean;
  46 typedef CFIndex CFPropertyListFormat;
  47 typedef uint32_t CFStringEncoding;
  48
  49 // kCFStringEncodingASCII analog.
  50 #define CF_STRING_ENCODING_ASCII 0x0600
  51 // kCFStringEncodingUTF8 analog.
  52 #define CF_STRING_ENCODING_UTF8 0x08000100
  53 #define CF_PROPERTY_LIST_IMMUTABLE 0
  54
  55 typedef CFDataRef (*CFDataCreateWithBytesNoCopyFuncTy)(CFAllocatorRef,
  56                                                        const UInt8 *, CFIndex,
  57                                                        CFAllocatorRef);
  58 typedef CFPropertyListRef (*CFPropertyListCreateWithDataFuncTy)(
  59     CFAllocatorRef, CFDataRef, CFOptionFlags, CFPropertyListFormat *,
  60     CFErrorRef *);
  61 typedef CFPropertyListRef (*CFPropertyListCreateFromXMLDataFuncTy)(
  62     CFAllocatorRef, CFDataRef, CFOptionFlags, CFStringRef *);
  63 typedef CFStringRef (*CFStringCreateWithCStringNoCopyFuncTy)(CFAllocatorRef,
  64                                                              const char *,
  65                                                              CFStringEncoding,
  66                                                              CFAllocatorRef);
  67 typedef const void *(*CFDictionaryGetValueFuncTy)(CFDictionaryRef,
  68                                                   const void *);
  69 typedef CFTypeID (*CFGetTypeIDFuncTy)(CFTypeRef);
  70 typedef CFTypeID (*CFStringGetTypeIDFuncTy)(void);
  71 typedef Boolean (*CFStringGetCStringFuncTy)(CFStringRef, char *, CFIndex,
  72                                             CFStringEncoding);
  73 typedef void (*CFReleaseFuncTy)(CFTypeRef);
  74
  75 // Find and parse the SystemVersion.plist file.
  76 static void parseSystemVersionPList(void *Unused) {
  77   (void)Unused;
  78   // Load CoreFoundation dynamically
  79   const void *NullAllocator = dlsym(RTLD_DEFAULT, "kCFAllocatorNull");
  80   if (!NullAllocator)
  81     return;
  82   const CFAllocatorRef AllocatorNull = *(const CFAllocatorRef *)NullAllocator;
  83   CFDataCreateWithBytesNoCopyFuncTy CFDataCreateWithBytesNoCopyFunc =
  84       (CFDataCreateWithBytesNoCopyFuncTy)dlsym(RTLD_DEFAULT,
  85                                                "CFDataCreateWithBytesNoCopy");
  86   if (!CFDataCreateWithBytesNoCopyFunc)
  87     return;
  88   CFPropertyListCreateWithDataFuncTy CFPropertyListCreateWithDataFunc =
  89       (CFPropertyListCreateWithDataFuncTy)dlsym(RTLD_DEFAULT,
  90                                                 "CFPropertyListCreateWithData");
  91 // CFPropertyListCreateWithData was introduced only in macOS 10.6+, so it
  92 // will be NULL on earlier OS versions.
  93 #pragma clang diagnostic push
  94 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
  95   CFPropertyListCreateFromXMLDataFuncTy CFPropertyListCreateFromXMLDataFunc =
  96       (CFPropertyListCreateFromXMLDataFuncTy)dlsym(
  97           RTLD_DEFAULT, "CFPropertyListCreateFromXMLData");
  98 #pragma clang diagnostic pop
  99   // CFPropertyListCreateFromXMLDataFunc is deprecated in macOS 10.10, so it
 100   // might be NULL in future OS versions.
 101   if (!CFPropertyListCreateWithDataFunc && !CFPropertyListCreateFromXMLDataFunc)
 102     return;
 103   CFStringCreateWithCStringNoCopyFuncTy CFStringCreateWithCStringNoCopyFunc =
 104       (CFStringCreateWithCStringNoCopyFuncTy)dlsym(
 105           RTLD_DEFAULT, "CFStringCreateWithCStringNoCopy");
 106   if (!CFStringCreateWithCStringNoCopyFunc)
 107     return;
 108   CFDictionaryGetValueFuncTy CFDictionaryGetValueFunc =
 109       (CFDictionaryGetValueFuncTy)dlsym(RTLD_DEFAULT, "CFDictionaryGetValue");
 110   if (!CFDictionaryGetValueFunc)
 111     return;
 112   CFGetTypeIDFuncTy CFGetTypeIDFunc =
 113       (CFGetTypeIDFuncTy)dlsym(RTLD_DEFAULT, "CFGetTypeID");
 114   if (!CFGetTypeIDFunc)
 115     return;
 116   CFStringGetTypeIDFuncTy CFStringGetTypeIDFunc =
 117       (CFStringGetTypeIDFuncTy)dlsym(RTLD_DEFAULT, "CFStringGetTypeID");
 118   if (!CFStringGetTypeIDFunc)
 119     return;
 120   CFStringGetCStringFuncTy CFStringGetCStringFunc =
 121       (CFStringGetCStringFuncTy)dlsym(RTLD_DEFAULT, "CFStringGetCString");
 122   if (!CFStringGetCStringFunc)
 123     return;
 124   CFReleaseFuncTy CFReleaseFunc =
 125       (CFReleaseFuncTy)dlsym(RTLD_DEFAULT, "CFRelease");
 126   if (!CFReleaseFunc)
 127     return;
 128
 129   char *PListPath = "/System/Library/CoreServices/SystemVersion.plist";
 130
 131 #if TARGET_OS_SIMULATOR
 132   char *PListPathPrefix = getenv("IPHONE_SIMULATOR_ROOT");
 133   if (!PListPathPrefix)
 134     return;
 135   char FullPath[strlen(PListPathPrefix) + strlen(PListPath) + 1];
 136   strcpy(FullPath, PListPathPrefix);
 137   strcat(FullPath, PListPath);
 138   PListPath = FullPath;
 139 #endif
 140   FILE *PropertyList = fopen(PListPath, "r");
 141   if (!PropertyList)
 142     return;
 143
 144   // Dynamically allocated stuff.
 145   CFDictionaryRef PListRef = NULL;
 146   CFDataRef FileContentsRef = NULL;
 147   UInt8 *PListBuf = NULL;
 148
 149   fseek(PropertyList, 0, SEEK_END);
 150   long PListFileSize = ftell(PropertyList);
 151   if (PListFileSize < 0)
 152     goto Fail;
 153   rewind(PropertyList);
 154
 155   PListBuf = malloc((size_t)PListFileSize);
 156   if (!PListBuf)
 157     goto Fail;
 158
 159   size_t NumRead = fread(PListBuf, 1, (size_t)PListFileSize, PropertyList);
 160   if (NumRead != (size_t)PListFileSize)
 161     goto Fail;
 162
 163   // Get the file buffer into CF's format. We pass in a null allocator here *
 164   // because we free PListBuf ourselves
 165   FileContentsRef = (*CFDataCreateWithBytesNoCopyFunc)(
 166       NULL, PListBuf, (CFIndex)NumRead, AllocatorNull);
 167   if (!FileContentsRef)
 168     goto Fail;
 169
 170   if (CFPropertyListCreateWithDataFunc)
 171     PListRef = (*CFPropertyListCreateWithDataFunc)(
 172         NULL, FileContentsRef, CF_PROPERTY_LIST_IMMUTABLE, NULL, NULL);
 173   else
 174     PListRef = (*CFPropertyListCreateFromXMLDataFunc)(
 175         NULL, FileContentsRef, CF_PROPERTY_LIST_IMMUTABLE, NULL);
 176   if (!PListRef)
 177     goto Fail;
 178
 179   CFStringRef ProductVersion = (*CFStringCreateWithCStringNoCopyFunc)(
 180       NULL, "ProductVersion", CF_STRING_ENCODING_ASCII, AllocatorNull);
 181   if (!ProductVersion)
 182     goto Fail;
 183   CFTypeRef OpaqueValue = (*CFDictionaryGetValueFunc)(PListRef, ProductVersion);
 184   (*CFReleaseFunc)(ProductVersion);
 185   if (!OpaqueValue ||
 186       (*CFGetTypeIDFunc)(OpaqueValue) != (*CFStringGetTypeIDFunc)())
 187     goto Fail;
 188
 189   char VersionStr[32];
 190   if (!(*CFStringGetCStringFunc)((CFStringRef)OpaqueValue, VersionStr,
 191                                  sizeof(VersionStr), CF_STRING_ENCODING_UTF8))
 192     goto Fail;
 193   sscanf(VersionStr, "%d.%d.%d", &GlobalMajor, &GlobalMinor, &GlobalSubminor);
 194
 195 Fail:
 196   if (PListRef)
 197     (*CFReleaseFunc)(PListRef);
 198   if (FileContentsRef)
 199     (*CFReleaseFunc)(FileContentsRef);
 200   free(PListBuf);
 201   fclose(PropertyList);
 202 }
 203
 204 int32_t __isOSVersionAtLeast(int32_t Major, int32_t Minor, int32_t Subminor) {
 205   // Populate the global version variables, if they haven't already.
 206   dispatch_once_f(&DispatchOnceCounter, NULL, parseSystemVersionPList);
 207
 208   if (Major < GlobalMajor)
 209     return 1;
 210   if (Major > GlobalMajor)
 211     return 0;
 212   if (Minor < GlobalMinor)
 213     return 1;
 214   if (Minor > GlobalMinor)
 215     return 0;
 216   return Subminor <= GlobalSubminor;
 217 }
 218
 219 #else
 220
 221 // Silence an empty translation unit warning.
 222 typedef int unused;
 223
 224 #endif