[stackprotector] Use analysis from the StackProtector pass for stack layout in PEI a nd LocalStackSlot passes.

This changes the MachineFrameInfo API to use the new SSPLayoutKind information
produced by the StackProtector pass (instead of a boolean flag) and updates a
few pass dependencies (to preserve the SSP analysis).

The stack layout follows the same approach used prior to this change - i.e.,
only LargeArray stack objects will be placed near the canary and everything
else will be laid out normally.  After this change, structures containing large
arrays will also be placed near the canary - a case previously missed by the
old implementation.

Out of tree targets will need to update their usage of
MachineFrameInfo::CreateStackObject to remove the MayNeedSP argument. 

The next patch will implement the rules for sspstrong and sspreq.  The end goal
is to support ssp-strong stack layout rules.

WIP.

Differential Revision: http://llvm-reviews.chandlerc.com/D2158

llvm-svn: 197653

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonRemoveSZExtArgs.cpp b/llvm/lib/Target/Hexagon/HexagonRemoveSZExtArgs.cpp
index 44234e85dc6..552cac22eef 100644
--- a/llvm/lib/Target/Hexagon/HexagonRemoveSZExtArgs.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonRemoveSZExtArgs.cpp
@@ -42,6 +42,7 @@ namespace {
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
       AU.addRequired<MachineFunctionAnalysis>();
       AU.addPreserved<MachineFunctionAnalysis>();
+      AU.addPreserved("stack-protector");
       FunctionPass::getAnalysisUsage(AU);
     }
   };