Activate UBSan for Power

[seurer]

Summary

This activates UBSan for the power architecture.

One test case is updated to allow for differences between power and other architectures in behavior when returning from main in certain instances.

[wschmidt]

One small concern inline...

projects/compiler-rt/test/ubsan/TestCases/Float/cast-overflow.cpp

91

Probably should make test_int static or filescope, as otherwise the compiler is within its rights to optimize this away despite the exception. Same comment applies several more times below.

[seurer]

projects/compiler-rt/test/ubsan/TestCases/Float/cast-overflow.cpp

91

Originally I had them as volatile but that changed the types in the error messages so I dropped it. I will switch them to static.

[wschmidt]

LGTM with that change. Thanks!

[seurer]

Committed revision 233813.

[samsonov]

Great. I've submitted r233862 to make sure we run check-ubsan on
http://lab.llvm.org:8011/builders/sanitizer-ppc64-linux1

projects/compiler-rt/cmake/config-ix.cmake

 filter_available_targets(ASAN_SUPPORTED_ARCH
   x86_64 i386 i686 powerpc64 powerpc64le arm mips mipsel mips64 mips64el)
 filter_available_targets(DFSAN_SUPPORTED_ARCH x86_64 mips64 mips64el)
 filter_available_targets(LSAN_SUPPORTED_ARCH x86_64 mips64 mips64el)
 filter_available_targets(MSAN_SUPPORTED_ARCH x86_64 mips64 mips64el)
 filter_available_targets(PROFILE_SUPPORTED_ARCH x86_64 i386 i686 arm mips mips64
   mipsel mips64el aarch64 powerpc64 powerpc64le)
 filter_available_targets(TSAN_SUPPORTED_ARCH x86_64 mips64 mips64el)
-filter_available_targets(UBSAN_SUPPORTED_ARCH x86_64 i386 i686 arm aarch64 mips mipsel mips64 mips64el)
+filter_available_targets(UBSAN_SUPPORTED_ARCH x86_64 i386 i686 arm aarch64 mips
+  mipsel mips64 mips64el powerpc64 powerpc64le)
 
 if(ANDROID)
   set(OS_NAME "Android")
 else()
   set(OS_NAME "${CMAKE_SYSTEM_NAME}")
 endif()
 
 if (SANITIZER_COMMON_SUPPORTED_ARCH AND NOT LLVM_USE_SANITIZER AND

projects/compiler-rt/lib/ubsan/ubsan_platform.h

 //
 //===----------------------------------------------------------------------===//
 #ifndef UBSAN_PLATFORM_H
 #define UBSAN_PLATFORM_H
 
 // Other platforms should be easy to add, and probably work as-is.
 #if (defined(__linux__) || defined(__FreeBSD__) || defined(__APPLE__)) && \
     (defined(__x86_64__) || defined(__i386__) || defined(__arm__) || \
-     defined(__aarch64__) || defined(__mips__))
+     defined(__aarch64__) || defined(__mips__) || defined(__powerpc64__))
 # define CAN_SANITIZE_UB 1
 #else
 # define CAN_SANITIZE_UB 0
 # error "UBSan not supported for this platform!"
 #endif
 
 #endif

projects/compiler-rt/lib/ubsan/ubsan_value.cc

#if 0
       case 16: {
         __fp16 Value;
         internal_memcpy(&Value, &Val, 4);
         return Value;
       }
 #endif
       case 32: {
         float Value;
-        internal_memcpy(&Value, &Val, 4);
+#if defined(__BIG_ENDIAN__)
+       // For big endian the float value is in the second 4 bytes
+       //  instead of the first 4 bytes.
+       internal_memcpy(&Value, ((const char*)&Val)+4, 4);
+#else 
+#endif
         return Value;
       }
       case 64: {
         double Value;
         internal_memcpy(&Value, &Val, 8);
         return Value;
       }
     }

projects/compiler-rt/test/ubsan/TestCases/Float/cast-overflow.cpp

#endif
   memcpy(&NaN, NaNVal, 4);
 
   double DblInf = (double)Inf; // ok
 
   switch (argv[1][0]) {
     // FIXME: Produce a source location for these checks and test for it here.
 
     // Floating point -> integer overflow.
-  case '0':
+  case '0': {
     // Note that values between 0x7ffffe00 and 0x80000000 may or may not
     // successfully round-trip, depending on the rounding mode.
     // CHECK-0: runtime error: value 2.14748{{.*}} is outside the range of representable values of type 'int'
-    return MaxFloatRepresentableAsInt + 0x80;
+    int test_int = MaxFloatRepresentableAsInt + 0x80;
+    return 0;
+    }
   case '1':
     // CHECK-1: runtime error: value -2.14748{{.*}} is outside the range of representable values of type 'int'
     return MinFloatRepresentableAsInt - 0x100;
   case '2': {
     // CHECK-2: runtime error: value -1 is outside the range of representable values of type 'unsigned int'
     volatile float f = -1.0;
     volatile unsigned u = (unsigned)f;
     return 0;
   }
-  case '3':
+  case '3': {
     // CHECK-3: runtime error: value 4.2949{{.*}} is outside the range of representable values of type 'unsigned int'
-    return (unsigned)(MaxFloatRepresentableAsUInt + 0x100);
+    int test_int = (unsigned)(MaxFloatRepresentableAsUInt + 0x100);
+    return 0;
+  }
 
-  case '4':
+  case '4': {
     // CHECK-4: runtime error: value {{.*}} is outside the range of representable values of type 'int'
-    return Inf;
+    int test_int = Inf;
+    return 0;
+  }
   case '5':
     // CHECK-5: runtime error: value {{.*}} is outside the range of representable values of type 'int'
     return NaN;
 
     // Integer -> floating point overflow.
-  case '6':
+  case '6': {
     // CHECK-6: {{runtime error: value 0xffffff00000000000000000000000001 is outside the range of representable values of type 'float'|__int128 not supported}}
 #ifdef __SIZEOF_INT128__
-    return (float)(FloatMaxAsUInt128 + 1);
+    int test_int = (float)(FloatMaxAsUInt128 + 1);
+    return 0;
 #else
     puts("__int128 not supported");
     return 0;
 #endif
+  }
   // FIXME: The backend cannot lower __fp16 operations on x86 yet.
   //case '7':
   //  (__fp16)65504; // ok
   //  // CHECK-7: runtime error: value 65505 is outside the range of representable values of type '__fp16'
   //  return (__fp16)65505;
 
     // Floating point -> floating point overflow.
   case '8':