From 70d2d3cd4519893bff442b14d09883e03565f2a1 Mon Sep 17 00:00:00 2001
From: Zachary Turner <zturner@google.com>
Date: Wed, 27 Aug 2014 17:06:22 +0000
Subject: [PATCH] Limit the symbol search in DynamicLibrary to the module that
 was opened.

Differential Revision: http://reviews.llvm.org/D5030

Reviewed By: Reid Kleckner, Rafael Espindola

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216563 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Support/DynamicLibrary.cpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/Support/DynamicLibrary.cpp b/lib/Support/DynamicLibrary.cpp
index d2b551e8a0a..40072636608 100644
--- a/lib/Support/DynamicLibrary.cpp
+++ b/lib/Support/DynamicLibrary.cpp
@@ -56,8 +56,15 @@ static DenseSet<void *> *OpenedHandles = nullptr;
 DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *filename,
                                                    std::string *errMsg) {
   SmartScopedLock<true> lock(*SymbolsMutex);
-
-  void *handle = dlopen(filename, RTLD_LAZY|RTLD_GLOBAL);
+  int flags = RTLD_LAZY | RTLD_GLOBAL;
+#if defined(__APPLE__)
+  // RTLD_FIRST is an apple specific flag which causes dlsym() to search only
+  // the module specified in |filename|, and not dependent modules.  This
+  // behavior would be desirable for other platforms as well, except that
+  // there's not a good way to implement it.
+  flags |= RTLD_FIRST;
+#endif
+  void *handle = dlopen(filename, flags);
   if (!handle) {
     if (errMsg) *errMsg = dlerror();
     return DynamicLibrary();