[MCJIT] Respect target endianness in RuntimeDyldMachO and RuntimeDyldChecker.

This patch may address some of the issues described in http://llvm.org/PR20640.

llvm-svn: 215938

1 files changed, 10 insertions, 1 deletions

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
index d244f45..02504a9 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
@@ -705,7 +705,16 @@ uint64_t RuntimeDyldCheckerImpl::readMemoryAtAddr(uint64_t SrcAddr,
   assert(PtrSizedAddr == SrcAddr && "Linker memory pointer out-of-range.");
   uint8_t *Src = reinterpret_cast<uint8_t *>(PtrSizedAddr);
   uint64_t Result = 0;
-  memcpy(&Result, Src, Size);
+
+  // If host and target endianness match use memcpy, otherwise copy in reverse
+  // order.
+  if (getRTDyld().IsTargetLittleEndian == sys::IsLittleEndianHost)
+    memcpy(&Result, Src, Size);
+  else {
+    uint8_t *Dst = reinterpret_cast<uint8_t*>(&Result) + Size - 1;
+    for (unsigned i = 0; i < Size; ++i)
+      *Dst-- = *Src++;
+  }
   return Result;
 }