From d47ac23154213c274ac2fea8b361f00dc7656033 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 17 Nov 2010 22:26:15 +0000
Subject: [PATCH] Implement -pie.

llvm-svn: 119577
---
 clang/include/clang/Driver/Options.td |  1 +
 clang/lib/Driver/Tools.cpp            | 25 +++++++++++++++++++------
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index db71fdeae214..360805b40f6d 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -562,6 +562,7 @@ def private__bundle : Flag<"-private_bundle">;
 def pthreads : Flag<"-pthreads">;
 def pthread : Flag<"-pthread">;
 def p : Flag<"-p">;
+def pie : Flag<"-pie">;
 def read__only__relocs : Separate<"-read_only_relocs">;
 def remap : Flag<"-remap">;
 def rewrite_objc : Flag<"-rewrite-objc">, Flags<[DriverOption]>,
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index b92089db6a60..aa1b4399169c 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -3224,6 +3224,9 @@ void linuxtools::Link::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back(A->getValue(Args));
   }
 
+  if (Args.hasArg(options::OPT_pie))
+    CmdArgs.push_back("-pie");
+
   if (Args.hasArg(options::OPT_rdynamic))
     CmdArgs.push_back("-export-dynamic");
 
@@ -3272,15 +3275,22 @@ void linuxtools::Link::ConstructJob(Compilation &C, const JobAction &JA,
   CmdArgs.push_back(Output.getFilename());
 
   if (!Args.hasArg(options::OPT_nostdlib)) {
-    if (!Args.hasArg(options::OPT_shared))
-      CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt1.o")));
+    const char *crt1 = NULL;
+    if (!Args.hasArg(options::OPT_shared)){
+      if (Args.hasArg(options::OPT_pie))
+        crt1 = "Scrt1.o";
+      else
+        crt1 = "crt1.o";
+    }
+    if (crt1)
+      CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crt1)));
 
     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crti.o")));
 
     const char *crtbegin;
     if (Args.hasArg(options::OPT_static))
       crtbegin = "crtbeginT.o";
-    else if (Args.hasArg(options::OPT_shared))
+    else if (Args.hasArg(options::OPT_shared) || Args.hasArg(options::OPT_pie))
       crtbegin = "crtbeginS.o";
     else
       crtbegin = "crtbegin.o";
@@ -3350,10 +3360,13 @@ void linuxtools::Link::ConstructJob(Compilation &C, const JobAction &JA,
         CmdArgs.push_back("-lgcc");
     }
 
-    if (Args.hasArg(options::OPT_shared))
-      CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtendS.o")));
+    const char *crtend;
+    if (Args.hasArg(options::OPT_shared) || Args.hasArg(options::OPT_pie))
+      crtend = "crtendS.o";
     else
-      CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtend.o")));
+      crtend = "crtend.o";
+
+    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crtend)));
 
     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtn.o")));
   }