dyld3/BootArgs.cpp

   1 //
   2 //  BootArgs.cpp
   3 //  dyld
   4 //
   5 //  Created by Louis Gerbarg on 11/14/18.
   6 //
   7
   8 #include <sys/types.h>
   9 #include <sys/sysctl.h>
  10 #include <TargetConditionals.h>
  11
  12 #include "Loading.h" // For internalInstall()
  13 #include "BootArgs.h"
  14
  15 namespace dyld3 {
  16 /*
  17 * Checks to see if there are any args that impact dyld. These args
  18 * can be set sevaral ways. These will only be honored on development
  19 * and Apple Internal builds.
  20 */
  21 bool BootArgs::contains(const char* arg)
  22 {
  23     //FIXME: Use strnstr(). Unfortunately we are missing an imp in libc.a
  24 #if TARGET_OS_SIMULATOR
  25     return false;
  26 #else
  27     // don't check for boot-args on customer installs
  28     if ( !internalInstall() )
  29         return false;
  30
  31     // get length of full boot-args string
  32     size_t len;
  33     if ( sysctlbyname("kern.bootargs", NULL, &len, NULL, 0) != 0 )
  34         return false;
  35
  36     // get copy of boot-args string
  37     char bootArgsBuffer[len];
  38     if ( sysctlbyname("kern.bootargs", bootArgsBuffer, &len, NULL, 0) != 0 )
  39         return false;
  40
  41     // return true if 'arg' is a sub-string of boot-args
  42     return (strstr(bootArgsBuffer, arg) != nullptr);
  43 #endif
  44 }
  45
  46 uint64_t BootArgs::_flags = 0;
  47
  48 bool BootArgs::forceCustomerCache() {
  49     return (_flags & kForceCustomerCacheMask);
  50 }
  51
  52 bool BootArgs::forceDyld2() {
  53     // If both force dyld2 and dyld3 are set then use dyld3
  54     if (_flags & kForceDyld3CacheMask) { return false; }
  55     if (_flags & kForceDyld2CacheMask) { return true; }
  56     if (contains("force_dyld2=1")) { return true; }
  57     return false;
  58 }
  59
  60 bool BootArgs::forceDyld3() {
  61     return ((_flags & kForceDyld3CacheMask) || contains("force_dyld3=1"));
  62 }
  63
  64 bool BootArgs::enableDyldTestMode() {
  65     return (_flags & kDyldTestModeMask);
  66 }
  67
  68 bool BootArgs::enableCompactImageInfo() {
  69     return (_flags & kEnableCompactImageInfoMask);
  70 }
  71
  72 void BootArgs::setFlags(uint64_t flags) {
  73 #if TARGET_IPHONE_SIMULATOR
  74     return;
  75 #else
  76     // don't check for boot-args on customer installs
  77     if ( !internalInstall() )
  78         return;
  79     _flags = flags;
  80 #endif
  81 }
  82 };