From bb174d2f1fd3b936c1c8b75b83c6fb15b3dece2c Mon Sep 17 00:00:00 2001
From: Jakub Jirutka <jakub@jirutka.cz>
Date: Sun, 16 Apr 2017 16:49:00 +0100
Subject: [PATCH 5/7] Enable PIE by default for Alpine Linux

Alpine Linux uses PIE by default.
---
 lib/Driver/ToolChains/Gnu.cpp   |  4 +++-
 lib/Driver/ToolChains/Linux.cpp |  5 ++++-
 test/Driver/pic.c               | 12 ++++++++++++
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/lib/Driver/ToolChains/Gnu.cpp b/lib/Driver/ToolChains/Gnu.cpp
index 40ad3f5..842afb9 100644
--- a/lib/Driver/ToolChains/Gnu.cpp
+++ b/lib/Driver/ToolChains/Gnu.cpp
@@ -443,7 +443,9 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   if (!D.SysRoot.empty())
     CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
 
-  if (IsPIE)
+  if (Args.hasArg(options::OPT_nopie))
+     CmdArgs.push_back("-nopie");
+  else if (IsPIE)
     CmdArgs.push_back("-pie");
 
   if (Args.hasArg(options::OPT_rdynamic))
diff --git a/lib/Driver/ToolChains/Linux.cpp b/lib/Driver/ToolChains/Linux.cpp
index 9eea3f0..ce9cf35 100644
--- a/lib/Driver/ToolChains/Linux.cpp
+++ b/lib/Driver/ToolChains/Linux.cpp
@@ -819,7 +819,10 @@ void Linux::AddIAMCUIncludeArgs(const ArgList &DriverArgs,
   }
 }
 
-bool Linux::isPIEDefault() const { return getSanitizerArgs().requiresPIE(); }
+bool Linux::isPIEDefault() const {
+  return getSanitizerArgs().requiresPIE() || 
+         Linux::getTriple().getVendorName().compare("alpine") == 0;
+}
 
 SanitizerMask Linux::getSupportedSanitizers() const {
   const bool IsX86 = getTriple().getArch() == llvm::Triple::x86;
diff --git a/test/Driver/pic.c b/test/Driver/pic.c
index 6b01c58..0643edd 100644
--- a/test/Driver/pic.c
+++ b/test/Driver/pic.c
@@ -251,6 +251,18 @@
 // RUN: %clang %s -target i386-pc-openbsd -no-pie -### 2>&1 \
 // RUN:   | FileCheck %s --check-prefix=CHECK-NOPIE-LD
 //
+// On Alpine Linux, we want similar PIE-by-default behavior
+// RUN: %clang -c %s -target x86_64-alpine-linux-musl -### 2>&1 \
+// RUN:   | FileCheck %s --check-prefix=CHECK-PIE2
+// RUN: %clang -c %s -target i686-alpine-linux-musl -### 2>&1 \
+// RUN:   | FileCheck %s --check-prefix=CHECK-PIE2
+// RUN: %clang -c %s -target armv6-alpine-linux-musleabihf -### 2>&1 \
+// RUN:   | FileCheck %s --check-prefix=CHECK-PIE2
+// RUN: %clang -c %s -target armv7-alpine-linux-musleabihf -### 2>&1 \
+// RUN:   | FileCheck %s --check-prefix=CHECK-PIE2
+// RUN: %clang %s -target x86_64-alpine-linux-musl -nopie -### 2>&1 \
+// RUN:   | FileCheck %s --check-prefix=CHECK-NOPIE-LD
+//
 // On Android PIC is enabled by default
 // RUN: %clang -c %s -target i686-linux-android -### 2>&1 \
 // RUN:   | FileCheck %s --check-prefix=CHECK-PIC2
-- 
2.14.1

