Stack realignment is a tristate. Add -mno-stackrealign to turn off all stack

realignment, even with locals with alignment exceeding the ABI guarantee.

llvm-svn: 145909

1 files changed, 11 insertions, 2 deletions

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 074be43fdb4..4987b0a81f0 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1796,8 +1796,17 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back(Args.MakeArgString(Twine(StackProtectorLevel)));
   }
 
-  if (Args.hasArg(options::OPT_mstackrealign))
-    CmdArgs.push_back("-mstackrealign");
+  // Translate -mstackrealign
+  if (Args.hasFlag(options::OPT_mstackrealign, options::OPT_mno_stackrealign,
+                   false)) {
+    CmdArgs.push_back("-backend-option");
+    CmdArgs.push_back("-force-align-stack");
+  }
+  if (!Args.hasFlag(options::OPT_mno_stackrealign, options::OPT_mstackrealign,
+                   false)) {
+    CmdArgs.push_back(Args.MakeArgString("-mstackrealign"));
+  }
+
   if (Args.hasArg(options::OPT_mstack_alignment)) {
     StringRef alignment = Args.getLastArgValue(options::OPT_mstack_alignment);
     CmdArgs.push_back(Args.MakeArgString("-mstack-alignment=" + alignment));