From 20c918dfed5830f6d0c54c9c38817bd660cb6a13 Mon Sep 17 00:00:00 2001
From: Bob Wilson <bob.wilson@apple.com>
Date: Wed, 16 Nov 2011 07:12:00 +0000
Subject: [PATCH] Update the SP in the SjLj jmpbuf whenever it changes. 
 <rdar://problem/10444602>

This same basic code was in the older version of the SjLj exception handling,
but it was removed in the recent revisions to that code.  It needs to be there.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144782 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SjLjEHPrepare.cpp | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp
index ac88441bf9a..5d60bc9b751 100644
--- a/lib/CodeGen/SjLjEHPrepare.cpp
+++ b/lib/CodeGen/SjLjEHPrepare.cpp
@@ -48,10 +48,10 @@ namespace {
     Constant *BuiltinSetjmpFn;
     Constant *FrameAddrFn;
     Constant *StackAddrFn;
+    Constant *StackRestoreFn;
     Constant *LSDAAddrFn;
     Value *PersonalityFn;
     Constant *CallSiteFn;
-    Constant *DispatchSetupFn;
     Constant *FuncCtxFn;
     Value *CallSite;
   public:
@@ -107,11 +107,10 @@ bool SjLjEHPass::doInitialization(Module &M) {
                           (Type *)0);
   FrameAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::frameaddress);
   StackAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::stacksave);
+  StackRestoreFn = Intrinsic::getDeclaration(&M, Intrinsic::stackrestore);
   BuiltinSetjmpFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setjmp);
   LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda);
   CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite);
-  DispatchSetupFn
-    = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_dispatch_setup);
   FuncCtxFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_functioncontext);
   PersonalityFn = 0;
 
@@ -460,6 +459,25 @@ bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) {
                                         EntryBB->getTerminator());
   Register->setDoesNotThrow();
 
+  // Following any allocas not in the entry block, update the saved SP in the
+  // jmpbuf to the new value.
+  for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
+    if (BB == F.begin())
+      continue;
+    for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
+      if (CallInst *CI = dyn_cast<CallInst>(I)) {
+        if (CI->getCalledFunction() != StackRestoreFn)
+          continue;
+      } else if (!isa<AllocaInst>(I)) {
+        continue;
+      }
+      Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp");
+      StackAddr->insertAfter(I);
+      Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true);
+      StoreStackAddr->insertAfter(StackAddr);
+    }
+  }
+
   // Finally, for any returns from this function, if this function contains an
   // invoke, add a call to unregister the function context.
   for (unsigned I = 0, E = Returns.size(); I != E; ++I)
-- 
2.34.1