sanitizer: Fix endianness checks for gcc

[• koriakin]

Summary

BIG_ENDIAN and LITTLE_ENDIAN are not supported by gcc, which
eg. for ubsan Value::getFloatValue will silently fall through to
the little endian branch, breaking display of float values by ubsan.
Use BYTE_ORDER == ORDER_BIG/LITTLE_ENDIAN as the condition
instead, which is supported by both clang and gcc.

Noticed while porting ubsan to s390x.

[• koriakin]

Ping?

[samsonov]

We use __BIG_ENDIAN__ and __LITTLE_ENDIAN__ macro in a few places in sanitizers. Let's update all these use cases to a more portable form for consistency.

[• koriakin]

Added a few other places in sanitizers. There are a few uses left, but these are in areas that shouldn't be hit by gcc/clang.

[samsonov]

LGTM. Thank you for fixing this!

[• koriakin]

I don't have svn write access, how can I get this patch commited?

compiler-rt/trunk/lib/asan/asan_report.cc

bool DescribeAddressIfStack(uptr addr, uptr access_size) {
 
   // Now we print the frame where the alloca has happened.
   // We print this frame as a stack trace with one element.
   // The symbolizer may print more than one frame if inlining was involved.
   // The frame numbers may be different than those in the stack trace printed
   // previously. That's unfortunate, but I have no better solution,
   // especially given that the alloca may be from entirely different place
   // (e.g. use-after-scope, or different thread's stack).
-#if defined(__powerpc64__) && defined(__BIG_ENDIAN__)
+#if defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
   // On PowerPC64 ELFv1, the address of a function actually points to a
   // three-doubleword data structure with the first field containing
   // the address of the function's code.
   access.frame_pc = *reinterpret_cast<uptr *>(access.frame_pc);
 #endif
   access.frame_pc += 16;
   Printf("%s", d.EndLocation());
   StackTrace alloca_stack(&access.frame_pc, 1);

compiler-rt/trunk/lib/sanitizer_common/sanitizer_symbolizer_libcdep.cc

 #elif defined(__x86_64__)
     const char* const kSymbolizerArch = "--default-arch=x86_64";
 #elif defined(__i386__)
     const char* const kSymbolizerArch = "--default-arch=i386";
 #elif defined(__aarch64__)
     const char* const kSymbolizerArch = "--default-arch=arm64";
 #elif defined(__arm__)
     const char* const kSymbolizerArch = "--default-arch=arm";
-#elif defined(__powerpc64__) && defined(__BIG_ENDIAN__)
+#elif defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
     const char* const kSymbolizerArch = "--default-arch=powerpc64";
-#elif defined(__powerpc64__) && defined(__LITTLE_ENDIAN__)
+#elif defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
     const char* const kSymbolizerArch = "--default-arch=powerpc64le";
 #else
     const char* const kSymbolizerArch = "--default-arch=unknown";
 #endif
 
     const char *const inline_flag = common_flags()->symbolize_inline_frames
                                         ? "--inlining=true"
                                         : "--inlining=false";

compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc

 #else
 struct ucontext_t {
   // The size is determined by looking at sizeof of real ucontext_t on linux.
   u64 opaque[936 / sizeof(u64) + 1];
 };
 #endif
 
 #if defined(__x86_64__) || defined(__mips__) \
-  || (defined(__powerpc64__) && defined(__BIG_ENDIAN__))
+  || (defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
 #define PTHREAD_ABI_BASE  "GLIBC_2.3.2"
 #elif defined(__aarch64__) || (defined(__powerpc64__) \
-  && defined(__LITTLE_ENDIAN__))
+  && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
 #define PTHREAD_ABI_BASE  "GLIBC_2.17"
 #endif
 
 extern "C" int pthread_attr_init(void *attr);
 extern "C" int pthread_attr_destroy(void *attr);
 DECLARE_REAL(int, pthread_attr_getdetachstate, void *, void *)
 extern "C" int pthread_attr_setstacksize(void *attr, uptr stacksize);
 extern "C" int pthread_key_create(unsigned *key, void (*destructor)(void* v));

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

#if 0
       case 16: {
         __fp16 Value;
         internal_memcpy(&Value, &Val, 4);
         return Value;
       }
 #endif
       case 32: {
         float Value;
-#if defined(__BIG_ENDIAN__)
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
        // For big endian the float value is in the last 4 bytes.
        // On some targets we may only have 4 bytes so we count backwards from
        // the end of Val to account for both the 32-bit and 64-bit cases.
        internal_memcpy(&Value, ((const char*)(&Val + 1)) - 4, 4);
 #else 
        internal_memcpy(&Value, &Val, 4);
 #endif
         return Value;