Index: lib/Basic/Targets.cpp
===================================================================
--- lib/Basic/Targets.cpp
+++ lib/Basic/Targets.cpp
@@ -639,7 +639,7 @@
     // RegParmMax is inherited from the underlying architecture
     this->LongDoubleFormat = &llvm::APFloat::IEEEdouble;
     if (Triple.getArch() == llvm::Triple::arm) {
-      this->DescriptionString = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S128";
+      // Handled on arm's setABI.
     } else if (Triple.getArch() == llvm::Triple::x86) {
       this->DescriptionString = "e-m:e-p:32:32-i64:64-n8:16:32-S128";
     } else if (Triple.getArch() == llvm::Triple::x86_64) {
@@ -3722,6 +3722,9 @@
                           "-a:0:32"
                           "-n32"
                           "-S64";
+    } else if (T.isOSNaCl()) {
+      assert(!BigEndian && "NaCl on ARM does not support big endian");
+      DescriptionString = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S128";
     } else {
       DescriptionString =
           BigEndian ? "E-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
Index: test/CodeGen/target-data.c
===================================================================
--- test/CodeGen/target-data.c
+++ test/CodeGen/target-data.c
@@ -66,8 +66,8 @@
 // RUN: FileCheck %s -check-prefix=X86_64-NACL
 // X86_64-NACL: target datalayout = "e-m:e-p:32:32-i64:64-n8:16:32:64-S128"
 
-// RUN: %clang_cc1 -triple arm-nacl-gnueabi -o - -emit-llvm %s | \
-// RUN: FileCheck %s -check-prefix=ARM-NACL
+// RUN: %clang_cc1 -triple arm-nacl-gnueabi -o - -emit-llvm %s \
+// RUN:   -target-abi aapcs-linux | FileCheck %s -check-prefix=ARM-NACL
 // ARM-NACL: target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S128"
 
 // RUN: %clang_cc1 -triple mipsel-nacl -o - -emit-llvm %s | \