From a4d5b34f73e4cde7dec3193157285be5de846e74 Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames@gmail.com>
Date: Tue, 20 Nov 2018 01:01:26 +0000
Subject: [ExecutionEngine][Interpreter] Fix out-of-bounds array access.

If args is empty then accesing element 0 is illegal.

https://reviews.llvm.org/D53556

Patch by Eugene Sharygin. Thanks Eugene!

llvm-svn: 347281
---
 llvm/lib/ExecutionEngine/Interpreter/ExternalFunctions.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'llvm/lib')

diff --git a/llvm/lib/ExecutionEngine/Interpreter/ExternalFunctions.cpp b/llvm/lib/ExecutionEngine/Interpreter/ExternalFunctions.cpp
index 64dca930722..044d9b7f27a 100644
--- a/llvm/lib/ExecutionEngine/Interpreter/ExternalFunctions.cpp
+++ b/llvm/lib/ExecutionEngine/Interpreter/ExternalFunctions.cpp
@@ -227,7 +227,8 @@ static bool ffiInvoke(RawFunc Fn, Function *F, ArrayRef<GenericValue> ArgVals,
   Type *RetTy = FTy->getReturnType();
   ffi_type *rtype = ffiTypeFor(RetTy);
 
-  if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, NumArgs, rtype, &args[0]) == FFI_OK) {
+  if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, NumArgs, rtype, args.data()) ==
+      FFI_OK) {
     SmallVector<uint8_t, 128> ret;
     if (RetTy->getTypeID() != Type::VoidTyID)
       ret.resize(TD.getTypeStoreSize(RetTy));
-- 
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