From a8fbef44fe2347942e2eb76e5b9144d74b5bdc7e Mon Sep 17 00:00:00 2001
From: Alex Lorenz <arphaman@gmail.com>
Date: Thu, 23 Mar 2017 11:14:27 +0000
Subject: [CodeGen] Emit a CoreFoundation link guard when @available is used

After r297760, __isOSVersionAtLeast in compiler-rt loads the CoreFoundation
symbols at runtime. This means that `@available` will always fail when used in a
binary without a linked CoreFoundation.

This commit forces Clang to emit a reference to a CoreFoundation symbol when
`@available` is used to ensure that linking will fail when CoreFoundation isn't
linked with the build product.

rdar://31039592

Differential Revision: https://reviews.llvm.org/D30977

llvm-svn: 298588
---
 clang/lib/CodeGen/CodeGenModule.cpp | 1 +
 1 file changed, 1 insertion(+)

(limited to 'clang/lib/CodeGen/CodeGenModule.cpp')

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index ca1850e..89ee7fc 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -414,6 +414,7 @@ void CodeGenModule::Release() {
     CoverageMapping->emit();
   if (CodeGenOpts.SanitizeCfiCrossDso)
     CodeGenFunction(*this).EmitCfiCheckFail();
+  emitAtAvailableLinkGuard();
   emitLLVMUsed();
   if (SanStats)
     SanStats->finish();
-- 
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