From f4236bfdbdb6f8236a2efdc5cda5d7fa40786b9f Mon Sep 17 00:00:00 2001
From: George Karpenkov <ekarpenkov@apple.com>
Date: Thu, 29 Jun 2017 19:52:33 +0000
Subject: [PATCH] [libFuzzer] Do not link in libFuzzer with -fsanitize=fuzzer
 when producing a shared object

https://reviews.llvm.org/D34791

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@306733 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Driver/ToolChains/CommonArgs.cpp | 3 ++-
 lib/Driver/ToolChains/Darwin.cpp     | 2 +-
 test/Driver/fuzzer.c                 | 4 ++++
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/Driver/ToolChains/CommonArgs.cpp b/lib/Driver/ToolChains/CommonArgs.cpp
index 1991b2ecd8..e8bb703054 100644
--- a/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/lib/Driver/ToolChains/CommonArgs.cpp
@@ -617,7 +617,8 @@ bool tools::addSanitizerRuntimes(const ToolChain &TC, const ArgList &Args,
                            NonWholeStaticRuntimes, HelperStaticRuntimes,
                            RequiredSymbols);
   // Inject libfuzzer dependencies.
-  if (TC.getSanitizerArgs().needsFuzzer()) {
+  if (TC.getSanitizerArgs().needsFuzzer()
+      && !Args.hasArg(options::OPT_shared)) {
     addLibFuzzerRuntime(TC, Args, CmdArgs);
   }
 
diff --git a/lib/Driver/ToolChains/Darwin.cpp b/lib/Driver/ToolChains/Darwin.cpp
index bfe685e70d..13cda0d0a1 100644
--- a/lib/Driver/ToolChains/Darwin.cpp
+++ b/lib/Driver/ToolChains/Darwin.cpp
@@ -1053,7 +1053,7 @@ void DarwinClang::AddLinkRuntimeLibArgs(const ArgList &Args,
     AddLinkSanitizerLibArgs(Args, CmdArgs, "ubsan");
   if (Sanitize.needsTsanRt())
     AddLinkSanitizerLibArgs(Args, CmdArgs, "tsan");
-  if (Sanitize.needsFuzzer())
+  if (Sanitize.needsFuzzer() && !Args.hasArg(options::OPT_dynamiclib))
     AddFuzzerLinkArgs(Args, CmdArgs);
   if (Sanitize.needsStatsRt()) {
     StringRef OS = isTargetMacOS() ? "osx" : "iossim";
diff --git a/test/Driver/fuzzer.c b/test/Driver/fuzzer.c
index e534a73a64..35bf4315c9 100644
--- a/test/Driver/fuzzer.c
+++ b/test/Driver/fuzzer.c
@@ -15,6 +15,10 @@
 //
 // CHECK-LIBCXX-DARWIN: -lc++
 
+// Check that we don't link in libFuzzer.a when producing a shared object.
+// RUN: %clang -fsanitize=fuzzer %s -shared -o %t.so -### 2>&1 | FileCheck --check-prefixes=CHECK-NOLIB-SO %s
+// CHECK-NOLIB-SO-NOT: libLLVMFuzzer.a
+
 int LLVMFuzzerTestOneInput(const char *Data, long Size) {
   return 0;
 }
-- 
2.40.0