[Driver] add initial support for alpine linux

set -pie as default for musl linux targets
add detection of alpine linux
append appropriate compile flags for alpine

Reviewers: rnk

Differential Revision: https://reviews.llvm.org/D39588

llvm-svn: 318608

2 files changed, 11 insertions, 3 deletions

diff --git a/clang/lib/Driver/Distro.cpp b/clang/lib/Driver/Distro.cpp
index 9a0b854e32f..f15c919b9aa 100644
--- a/clang/lib/Driver/Distro.cpp
+++ b/clang/lib/Driver/Distro.cpp
@@ -129,6 +129,9 @@ static Distro::DistroType DetectDistro(vfs::FileSystem &VFS) {
   if (VFS.exists("/etc/exherbo-release"))
     return Distro::Exherbo;
 
+  if (VFS.exists("/etc/alpine-release"))
+    return Distro::AlpineLinux;
+
   if (VFS.exists("/etc/arch-release"))
     return Distro::ArchLinux;
 
diff --git a/clang/lib/Driver/ToolChains/Linux.cpp b/clang/lib/Driver/ToolChains/Linux.cpp
index 9b722166c5f..ca042f38db8 100644
--- a/clang/lib/Driver/ToolChains/Linux.cpp
+++ b/clang/lib/Driver/ToolChains/Linux.cpp
@@ -210,7 +210,12 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
 
   Distro Distro(D.getVFS());
 
-  if (Distro.IsOpenSUSE() || Distro.IsUbuntu()) {
+  if (Distro.IsAlpineLinux()) {
+    ExtraOpts.push_back("-z");
+    ExtraOpts.push_back("now");
+  }
+
+  if (Distro.IsOpenSUSE() || Distro.IsUbuntu() || Distro.IsAlpineLinux()) {
     ExtraOpts.push_back("-z");
     ExtraOpts.push_back("relro");
   }
@@ -232,7 +237,7 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
   // Android loader does not support .gnu.hash.
   // Hexagon linker/loader does not support .gnu.hash
   if (!IsMips && !IsAndroid && !IsHexagon) {
-    if (Distro.IsRedhat() || Distro.IsOpenSUSE() ||
+    if (Distro.IsRedhat() || Distro.IsOpenSUSE() || Distro.IsAlpineLinux() ||
         (Distro.IsUbuntu() && Distro >= Distro::UbuntuMaverick))
       ExtraOpts.push_back("--hash-style=gnu");
 
@@ -812,7 +817,7 @@ void Linux::AddIAMCUIncludeArgs(const ArgList &DriverArgs,
 
 bool Linux::isPIEDefault() const {
   return (getTriple().isAndroid() && !getTriple().isAndroidVersionLT(16)) ||
-         getSanitizerArgs().requiresPIE();
+          getTriple().isMusl() || getSanitizerArgs().requiresPIE();
 }
 
 SanitizerMask Linux::getSupportedSanitizers() const {