[RuntimeDyld][MachO] Fix handling of empty eh-frame sections.

This patch switches from an unguarded to a guarded loop for eh-frame record
fixups. In the unguarded version we would always make at least one call to
processFDE, which would then crash trying to fix up a frame that didn't exist.

Fixes <rdar://problem/24301582>

llvm-svn: 259103

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
index 739e8d65dbf..96d6fcbcf4c 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
@@ -302,9 +302,9 @@ void RuntimeDyldMachOCRTPBase<Impl>::registerEHFrames() {
 
     uint8_t *P = EHFrame->getAddress();
     uint8_t *End = P + EHFrame->getSize();
-    do {
+    while (P != End) {
       P = processFDE(P, DeltaForText, DeltaForEH);
-    } while (P != End);
+    }
 
     MemMgr.registerEHFrames(EHFrame->getAddress(), EHFrame->getLoadAddress(),
                             EHFrame->getSize());