summaryrefslogtreecommitdiff
path: root/lib/builtins/os_version_check.c
blob: e0d40edc7e38640657328401649c824d1abbb550 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
/* ===-- os_version_check.c - OS version checking  -------------------------===
 *
 *                     The LLVM Compiler Infrastructure
 *
 * This file is dual licensed under the MIT and the University of Illinois Open
 * Source Licenses. See LICENSE.TXT for details.
 *
 * ===----------------------------------------------------------------------===
 *
 * This file implements the function __isOSVersionAtLeast, used by
 * Objective-C's @available
 *
 * ===----------------------------------------------------------------------===
 */

#ifdef __APPLE__

#include <TargetConditionals.h>
#include <dispatch/dispatch.h>
#include <dlfcn.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* These three variables hold the host's OS version. */
static int32_t GlobalMajor, GlobalMinor, GlobalSubminor;
static dispatch_once_t DispatchOnceCounter;

/* We can't include <CoreFoundation/CoreFoundation.h> directly from here, so
 * just forward declare everything that we need from it. */

typedef const void *CFDataRef, *CFAllocatorRef, *CFPropertyListRef,
                   *CFStringRef, *CFDictionaryRef, *CFTypeRef, *CFErrorRef;

#if __LLP64__
typedef unsigned long long CFTypeID;
typedef unsigned long long CFOptionFlags;
typedef signed long long CFIndex;
#else
typedef unsigned long CFTypeID;
typedef unsigned long CFOptionFlags;
typedef signed long CFIndex;
#endif

typedef unsigned char UInt8;
typedef _Bool Boolean;
typedef CFIndex CFPropertyListFormat;
typedef uint32_t CFStringEncoding;

/* kCFStringEncodingASCII analog. */
#define CF_STRING_ENCODING_ASCII 0x0600
/* kCFStringEncodingUTF8 analog. */
#define CF_STRING_ENCODING_UTF8 0x08000100
#define CF_PROPERTY_LIST_IMMUTABLE 0

typedef CFDataRef (*CFDataCreateWithBytesNoCopyFuncTy)(CFAllocatorRef,
                                                       const UInt8 *, CFIndex,
                                                       CFAllocatorRef);
typedef CFPropertyListRef (*CFPropertyListCreateWithDataFuncTy)(
    CFAllocatorRef, CFDataRef, CFOptionFlags, CFPropertyListFormat *,
    CFErrorRef *);
typedef CFPropertyListRef (*CFPropertyListCreateFromXMLDataFuncTy)(
    CFAllocatorRef, CFDataRef, CFOptionFlags, CFStringRef *);
typedef CFStringRef (*CFStringCreateWithCStringNoCopyFuncTy)(CFAllocatorRef,
                                                             const char *,
                                                             CFStringEncoding,
                                                             CFAllocatorRef);
typedef const void *(*CFDictionaryGetValueFuncTy)(CFDictionaryRef,
                                                  const void *);
typedef CFTypeID (*CFGetTypeIDFuncTy)(CFTypeRef);
typedef CFTypeID (*CFStringGetTypeIDFuncTy)(void);
typedef Boolean (*CFStringGetCStringFuncTy)(CFStringRef, char *, CFIndex,
                                            CFStringEncoding);
typedef void (*CFReleaseFuncTy)(CFTypeRef);

/* Find and parse the SystemVersion.plist file. */
static void parseSystemVersionPList(void *Unused) {
  (void)Unused;
  /* Load CoreFoundation dynamically */
  const void *NullAllocator = dlsym(RTLD_DEFAULT, "kCFAllocatorNull");
  if (!NullAllocator)
    return;
  const CFAllocatorRef AllocatorNull = *(const CFAllocatorRef *)NullAllocator;
  CFDataCreateWithBytesNoCopyFuncTy CFDataCreateWithBytesNoCopyFunc =
      (CFDataCreateWithBytesNoCopyFuncTy)dlsym(RTLD_DEFAULT,
                                               "CFDataCreateWithBytesNoCopy");
  if (!CFDataCreateWithBytesNoCopyFunc)
    return;
  CFPropertyListCreateWithDataFuncTy CFPropertyListCreateWithDataFunc =
      (CFPropertyListCreateWithDataFuncTy)dlsym(
          RTLD_DEFAULT, "CFPropertyListCreateWithData");
/* CFPropertyListCreateWithData was introduced only in macOS 10.6+, so it
 * will be NULL on earlier OS versions. */
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
  CFPropertyListCreateFromXMLDataFuncTy CFPropertyListCreateFromXMLDataFunc =
      (CFPropertyListCreateFromXMLDataFuncTy)dlsym(
          RTLD_DEFAULT, "CFPropertyListCreateFromXMLData");
#pragma clang diagnostic pop
  /* CFPropertyListCreateFromXMLDataFunc is deprecated in macOS 10.10, so it
   * might be NULL in future OS versions. */
  if (!CFPropertyListCreateWithDataFunc && !CFPropertyListCreateFromXMLDataFunc)
    return;
  CFStringCreateWithCStringNoCopyFuncTy CFStringCreateWithCStringNoCopyFunc =
      (CFStringCreateWithCStringNoCopyFuncTy)dlsym(
          RTLD_DEFAULT, "CFStringCreateWithCStringNoCopy");
  if (!CFStringCreateWithCStringNoCopyFunc)
    return;
  CFDictionaryGetValueFuncTy CFDictionaryGetValueFunc =
      (CFDictionaryGetValueFuncTy)dlsym(RTLD_DEFAULT, "CFDictionaryGetValue");
  if (!CFDictionaryGetValueFunc)
    return;
  CFGetTypeIDFuncTy CFGetTypeIDFunc =
      (CFGetTypeIDFuncTy)dlsym(RTLD_DEFAULT, "CFGetTypeID");
  if (!CFGetTypeIDFunc)
    return;
  CFStringGetTypeIDFuncTy CFStringGetTypeIDFunc =
      (CFStringGetTypeIDFuncTy)dlsym(RTLD_DEFAULT, "CFStringGetTypeID");
  if (!CFStringGetTypeIDFunc)
    return;
  CFStringGetCStringFuncTy CFStringGetCStringFunc =
      (CFStringGetCStringFuncTy)dlsym(RTLD_DEFAULT, "CFStringGetCString");
  if (!CFStringGetCStringFunc)
    return;
  CFReleaseFuncTy CFReleaseFunc =
      (CFReleaseFuncTy)dlsym(RTLD_DEFAULT, "CFRelease");
  if (!CFReleaseFunc)
    return;

  char *PListPath = "/System/Library/CoreServices/SystemVersion.plist";

#if TARGET_OS_SIMULATOR
  char *PListPathPrefix = getenv("IPHONE_SIMULATOR_ROOT");
  if (!PListPathPrefix)
    return;
  char FullPath[strlen(PListPathPrefix) + strlen(PListPath) + 1];
  strcpy(FullPath, PListPathPrefix);
  strcat(FullPath, PListPath);
  PListPath = FullPath;
#endif
  FILE *PropertyList = fopen(PListPath, "r");
  if (!PropertyList)
    return;

  /* Dynamically allocated stuff. */
  CFDictionaryRef PListRef = NULL;
  CFDataRef FileContentsRef = NULL;
  UInt8 *PListBuf = NULL;

  fseek(PropertyList, 0, SEEK_END);
  long PListFileSize = ftell(PropertyList);
  if (PListFileSize < 0)
    goto Fail;
  rewind(PropertyList);

  PListBuf = malloc((size_t)PListFileSize);
  if (!PListBuf)
    goto Fail;

  size_t NumRead = fread(PListBuf, 1, (size_t)PListFileSize, PropertyList);
  if (NumRead != (size_t)PListFileSize)
    goto Fail;

  /* Get the file buffer into CF's format. We pass in a null allocator here *
   * because we free PListBuf ourselves */
  FileContentsRef = (*CFDataCreateWithBytesNoCopyFunc)(
      NULL, PListBuf, (CFIndex)NumRead, AllocatorNull);
  if (!FileContentsRef)
    goto Fail;

  if (CFPropertyListCreateWithDataFunc)
    PListRef = (*CFPropertyListCreateWithDataFunc)(
        NULL, FileContentsRef, CF_PROPERTY_LIST_IMMUTABLE, NULL, NULL);
  else
    PListRef = (*CFPropertyListCreateFromXMLDataFunc)(
        NULL, FileContentsRef, CF_PROPERTY_LIST_IMMUTABLE, NULL);
  if (!PListRef)
    goto Fail;

  CFStringRef ProductVersion = (*CFStringCreateWithCStringNoCopyFunc)(
      NULL, "ProductVersion", CF_STRING_ENCODING_ASCII, AllocatorNull);
  if (!ProductVersion)
    goto Fail;
  CFTypeRef OpaqueValue = (*CFDictionaryGetValueFunc)(PListRef, ProductVersion);
  (*CFReleaseFunc)(ProductVersion);
  if (!OpaqueValue ||
      (*CFGetTypeIDFunc)(OpaqueValue) != (*CFStringGetTypeIDFunc)())
    goto Fail;

  char VersionStr[32];
  if (!(*CFStringGetCStringFunc)((CFStringRef)OpaqueValue, VersionStr,
                                 sizeof(VersionStr), CF_STRING_ENCODING_UTF8))
    goto Fail;
  sscanf(VersionStr, "%d.%d.%d", &GlobalMajor, &GlobalMinor, &GlobalSubminor);

Fail:
  if (PListRef)
    (*CFReleaseFunc)(PListRef);
  if (FileContentsRef)
    (*CFReleaseFunc)(FileContentsRef);
  free(PListBuf);
  fclose(PropertyList);
}

int32_t __isOSVersionAtLeast(int32_t Major, int32_t Minor, int32_t Subminor) {
  /* Populate the global version variables, if they haven't already. */
  dispatch_once_f(&DispatchOnceCounter, NULL, parseSystemVersionPList);

  if (Major < GlobalMajor)
    return 1;
  if (Major > GlobalMajor)
    return 0;
  if (Minor < GlobalMinor)
    return 1;
  if (Minor > GlobalMinor)
    return 0;
  return Subminor <= GlobalSubminor;
}

#else

/* Silence an empty translation unit warning. */
typedef int unused;

#endif