From 2ba542c741c39691940f5d1de0bc88c22f46c430 Mon Sep 17 00:00:00 2001
From: Chandler Carruth <chandlerc@gmail.com>
Date: Mon, 14 May 2012 18:31:18 +0000
Subject: [PATCH] Teach the driver on Linux to respect -nodefaultlibs.

Patch from Andrew C. Morrow.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156771 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Driver/Tools.cpp       | 29 ++++++++++++++++-------------
 test/Driver/nodefaultlib.c |  8 ++++++++
 2 files changed, 24 insertions(+), 13 deletions(-)
 create mode 100644 test/Driver/nodefaultlib.c

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 769bd81e43..e3966694ae 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -5313,7 +5313,9 @@ void linuxtools::Link::ConstructJob(Compilation &C, const JobAction &JA,
 
   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs);
 
-  if (D.CCCIsCXX && !Args.hasArg(options::OPT_nostdlib)) {
+  if (D.CCCIsCXX &&
+      !Args.hasArg(options::OPT_nostdlib) &&
+      !Args.hasArg(options::OPT_nodefaultlibs)) {
     bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
       !Args.hasArg(options::OPT_static);
     if (OnlyLibstdcxxStatic)
@@ -5328,22 +5330,23 @@ void linuxtools::Link::ConstructJob(Compilation &C, const JobAction &JA,
   addAsanRTLinux(getToolChain(), Args, CmdArgs);
 
   if (!Args.hasArg(options::OPT_nostdlib)) {
-    if (Args.hasArg(options::OPT_static))
-      CmdArgs.push_back("--start-group");
-
-    AddLibgcc(ToolChain.getTriple(), D, CmdArgs, Args);
+    if (!Args.hasArg(options::OPT_nodefaultlibs)) {
+      if (Args.hasArg(options::OPT_static))
+        CmdArgs.push_back("--start-group");
 
-    if (Args.hasArg(options::OPT_pthread) ||
-        Args.hasArg(options::OPT_pthreads))
-      CmdArgs.push_back("-lpthread");
+      AddLibgcc(ToolChain.getTriple(), D, CmdArgs, Args);
 
-    CmdArgs.push_back("-lc");
+      if (Args.hasArg(options::OPT_pthread) ||
+          Args.hasArg(options::OPT_pthreads))
+        CmdArgs.push_back("-lpthread");
 
-    if (Args.hasArg(options::OPT_static))
-      CmdArgs.push_back("--end-group");
-    else
-      AddLibgcc(ToolChain.getTriple(), D, CmdArgs, Args);
+      CmdArgs.push_back("-lc");
 
+      if (Args.hasArg(options::OPT_static))
+        CmdArgs.push_back("--end-group");
+      else
+        AddLibgcc(ToolChain.getTriple(), D, CmdArgs, Args);
+    }
 
     if (!Args.hasArg(options::OPT_nostartfiles)) {
       const char *crtend;
diff --git a/test/Driver/nodefaultlib.c b/test/Driver/nodefaultlib.c
new file mode 100644
index 0000000000..518928a885
--- /dev/null
+++ b/test/Driver/nodefaultlib.c
@@ -0,0 +1,8 @@
+// RUN: %clang -target i686-pc-linux-gnu -### -nodefaultlibs %s 2> %t
+// RUN: FileCheck < %t %s
+//
+// CHECK-NOT: start-group
+// CHECK-NOT: -lgcc
+// CHECK-NOT: -lc
+// CHECK: crtbegin
+// CHECK: crtend
-- 
2.50.1