From: John McCall <rjmccall@apple.com>
Date: Fri, 12 Jan 2018 22:07:01 +0000 (+0000)
Subject: Allocate and access NormalCleanupDest with the natural alignment of i32.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3fb45fcca06352aeb81acf80f292e8f6a1ca2339;p=clang

Allocate and access NormalCleanupDest with the natural alignment of i32.

This alignment can be less than 4 on certain embedded targets, which may
not even be able to deal with 4-byte alignment on the stack.

Patch by Jacob Young!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@322406 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CGCleanup.cpp b/lib/CodeGen/CGCleanup.cpp
index 22055b2cb9..526def2cc2 100644
--- a/lib/CodeGen/CGCleanup.cpp
+++ b/lib/CodeGen/CGCleanup.cpp
@@ -624,7 +624,7 @@ static void destroyOptimisticNormalEntry(CodeGenFunction &CGF,
       si->eraseFromParent();
 
       // Destroy the load.
-      assert(condition->getOperand(0) == CGF.NormalCleanupDest);
+      assert(condition->getOperand(0) == CGF.NormalCleanupDest.getPointer());
       assert(condition->use_empty());
       condition->eraseFromParent();
     }
@@ -833,7 +833,7 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) {
         if (NormalCleanupDestSlot->hasOneUse()) {
           NormalCleanupDestSlot->user_back()->eraseFromParent();
           NormalCleanupDestSlot->eraseFromParent();
-          NormalCleanupDest = nullptr;
+          NormalCleanupDest = Address::invalid();
         }
 
         llvm::BasicBlock *BranchAfter = Scope.getBranchAfterBlock(0);
@@ -1250,10 +1250,10 @@ void CodeGenFunction::DeactivateCleanupBlock(EHScopeStack::stable_iterator C,
 }
 
 Address CodeGenFunction::getNormalCleanupDestSlot() {
-  if (!NormalCleanupDest)
+  if (!NormalCleanupDest.isValid())
     NormalCleanupDest =
-      CreateTempAlloca(Builder.getInt32Ty(), "cleanup.dest.slot");
-  return Address(NormalCleanupDest, CharUnits::fromQuantity(4));
+      CreateDefaultAlignTempAlloca(Builder.getInt32Ty(), "cleanup.dest.slot");
+  return NormalCleanupDest;
 }
 
 /// Emits all the code to cause the given temporary to be cleaned up.
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index 4a45b5ac19..e62d3e75b7 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -70,7 +70,7 @@ CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext)
       IsSanitizerScope(false), CurFuncIsThunk(false), AutoreleaseResult(false),
       SawAsmBlock(false), IsOutlinedSEHHelper(false), BlockInfo(nullptr),
       BlockPointer(nullptr), LambdaThisCaptureField(nullptr),
-      NormalCleanupDest(nullptr), NextCleanupDestIndex(1),
+      NormalCleanupDest(Address::invalid()), NextCleanupDestIndex(1),
       FirstBlockInfo(nullptr), EHResumeBlock(nullptr), ExceptionSlot(nullptr),
       EHSelectorSlot(nullptr), DebugInfo(CGM.getModuleDebugInfo()),
       DisableDebugInfo(false), DidCallStackSave(false), IndirectBranch(nullptr),
@@ -439,10 +439,11 @@ void CodeGenFunction::FinishFunction(SourceLocation EndLoc) {
   // if compiled with no optimizations. We do it for coroutine as the lifetime
   // of CleanupDestSlot alloca make correct coroutine frame building very
   // difficult.
-  if (NormalCleanupDest && isCoroutine()) {
+  if (NormalCleanupDest.isValid() && isCoroutine()) {
     llvm::DominatorTree DT(*CurFn);
-    llvm::PromoteMemToReg(NormalCleanupDest, DT);
-    NormalCleanupDest = nullptr;
+    llvm::PromoteMemToReg(
+        cast<llvm::AllocaInst>(NormalCleanupDest.getPointer()), DT);
+    NormalCleanupDest = Address::invalid();
   }
 }
 
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 228cbe69ac..e1db4c7499 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -434,7 +434,7 @@ public:
   };
 
   /// i32s containing the indexes of the cleanup destinations.
-  llvm::AllocaInst *NormalCleanupDest;
+  Address NormalCleanupDest;
 
   unsigned NextCleanupDestIndex;