[llvm] r175509 - Fix initialization-order bug in llvm::Support::TimeValue. TimeValue::now() is explicitly called during module initialization of lib/Support/Process.cpp. It reads the field of global object PosixZeroTime, which is not guaranteed to be initialized at this point. Found by AddressSanitizer with -fsanitize=init-order option.

[Alexey Samsonov]

Author: samsonov
Date: Tue Feb 19 05:35:39 2013
New Revision: 175509

URL: http://llvm.org/viewvc/llvm-project?rev=175509&view=rev
Log:
Fix initialization-order bug in llvm::Support::TimeValue. TimeValue::now() is explicitly called during module initialization of lib/Support/Process.cpp. It reads the field of global object PosixZeroTime, which is not guaranteed to be initialized at this point. Found by AddressSanitizer with -fsanitize=init-order option.

Modified:
    llvm/trunk/include/llvm/Support/TimeValue.h
    llvm/trunk/lib/Support/TimeValue.cpp
    llvm/trunk/lib/Support/Unix/TimeValue.inc

Modified: llvm/trunk/include/llvm/Support/TimeValue.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/TimeValue.h?rev=175509&r1=175508&r2=175509&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/TimeValue.h (original)
+++ llvm/trunk/include/llvm/Support/TimeValue.h Tue Feb 19 05:35:39 2013
@@ -240,7 +240,7 @@ namespace sys {
     /// Posix, correcting for the difference in Posix zero time.
     /// @brief Convert to unix time (100 nanoseconds since 12:00:00a Jan 1,1970)
     uint64_t toPosixTime() const {
-      uint64_t result = seconds_ - PosixZeroTime.seconds_;
+      uint64_t result = seconds_ - PosixZeroTimeSeconds;
       result += nanos_ / NANOSECONDS_PER_POSIX_TICK;
       return result;
     }
@@ -248,14 +248,14 @@ namespace sys {
     /// Converts the TimeValue into the corresponding number of seconds
     /// since the epoch (00:00:00 Jan 1,1970).
     uint64_t toEpochTime() const {
-      return seconds_ - PosixZeroTime.seconds_;
+      return seconds_ - PosixZeroTimeSeconds;
     }
 
     /// Converts the TimeValue into the corresponding number of "ticks" for
     /// Win32 platforms, correcting for the difference in Win32 zero time.
     /// @brief Convert to windows time (seconds since 12:00:00a Jan 1, 1601)
     uint64_t toWin32Time() const {
-      uint64_t result = seconds_ - Win32ZeroTime.seconds_;
+      uint64_t result = seconds_ - Win32ZeroTimeSeconds;
       result += nanos_ / NANOSECONDS_PER_WIN32_TICK;
       return result;
     }
@@ -264,7 +264,7 @@ namespace sys {
     /// correction for the Posix zero time.
     /// @brief Convert to timespec time (ala POSIX.1b)
     void getTimespecTime( uint64_t& seconds, uint32_t& nanos ) const {
-      seconds = seconds_ - PosixZeroTime.seconds_;
+      seconds = seconds_ - PosixZeroTimeSeconds;
       nanos = nanos_;
     }
 
@@ -331,7 +331,7 @@ namespace sys {
     /// TimeValue and assigns that value to \p this.
     /// @brief Convert seconds form PosixTime to TimeValue
     void fromEpochTime( SecondsType seconds ) {
-      seconds_ = seconds + PosixZeroTime.seconds_;
+      seconds_ = seconds + PosixZeroTimeSeconds;
       nanos_ = 0;
       this->normalize();
     }
@@ -340,7 +340,7 @@ namespace sys {
     /// corresponding TimeValue and assigns that value to \p this.
     /// @brief Convert seconds form Windows FILETIME to TimeValue
     void fromWin32Time( uint64_t win32Time ) {
-      this->seconds_ = win32Time / 10000000 + Win32ZeroTime.seconds_;
+      this->seconds_ = win32Time / 10000000 + Win32ZeroTimeSeconds;
       this->nanos_ = NanoSecondsType(win32Time  % 10000000) * 100;
     }
 
@@ -360,6 +360,9 @@ namespace sys {
     /// Store the values as a <timeval>.
     SecondsType      seconds_;///< Stores the seconds part of the TimeVal
     NanoSecondsType  nanos_;  ///< Stores the nanoseconds part of the TimeVal
+
+    static const SecondsType PosixZeroTimeSeconds;
+    static const SecondsType Win32ZeroTimeSeconds;
   /// @}
 
   };

Modified: llvm/trunk/lib/Support/TimeValue.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/TimeValue.cpp?rev=175509&r1=175508&r2=175509&view=diff
==============================================================================
--- llvm/trunk/lib/Support/TimeValue.cpp (original)
+++ llvm/trunk/lib/Support/TimeValue.cpp Tue Feb 19 05:35:39 2013
@@ -17,11 +17,16 @@
 namespace llvm {
 using namespace sys;
 
+const TimeValue::SecondsType
+  TimeValue::PosixZeroTimeSeconds = -946684800;
+const TimeValue::SecondsType
+  TimeValue::Win32ZeroTimeSeconds = -12591158400ULL;
+
 const TimeValue TimeValue::MinTime       = TimeValue ( INT64_MIN,0 );
 const TimeValue TimeValue::MaxTime       = TimeValue ( INT64_MAX,0 );
 const TimeValue TimeValue::ZeroTime      = TimeValue ( 0,0 );
-const TimeValue TimeValue::PosixZeroTime = TimeValue ( -946684800,0 );
-const TimeValue TimeValue::Win32ZeroTime = TimeValue ( -12591158400ULL,0 );
+const TimeValue TimeValue::PosixZeroTime = TimeValue ( PosixZeroTimeSeconds,0 );
+const TimeValue TimeValue::Win32ZeroTime = TimeValue ( Win32ZeroTimeSeconds,0 );
 
 void
 TimeValue::normalize( void ) {

Modified: llvm/trunk/lib/Support/Unix/TimeValue.inc
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/Unix/TimeValue.inc?rev=175509&r1=175508&r2=175509&view=diff
==============================================================================
--- llvm/trunk/lib/Support/Unix/TimeValue.inc (original)
+++ llvm/trunk/lib/Support/Unix/TimeValue.inc Tue Feb 19 05:35:39 2013
@@ -48,7 +48,8 @@ TimeValue TimeValue::now() {
   }
 
   return TimeValue(
-    static_cast<TimeValue::SecondsType>( the_time.tv_sec + PosixZeroTime.seconds_ ),
+    static_cast<TimeValue::SecondsType>( the_time.tv_sec +
+      PosixZeroTimeSeconds ),
     static_cast<TimeValue::NanoSecondsType>( the_time.tv_usec *
       NANOSECONDS_PER_MICROSECOND ) );
 }