Reland "[SEH] Use llvm.x86.seh.recoverfp for SEH filters on x64 as well as 32bit"

I forgot to initialize RecoverFP.

llvm-svn: 255731

1 files changed, 25 insertions, 19 deletions

diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index a064e6246a7..fce2e758196 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -1493,8 +1493,9 @@ struct CaptureFinder : ConstStmtVisitor<CaptureFinder> {
 };
 } // end anonymous namespace
 
-Address CodeGenFunction::recoverAddrOfEscapedLocal(
-    CodeGenFunction &ParentCGF, Address ParentVar, llvm::Value *ParentFP) {
+Address CodeGenFunction::recoverAddrOfEscapedLocal(CodeGenFunction &ParentCGF,
+                                                   Address ParentVar,
+                                                   llvm::Value *ParentFP) {
   llvm::CallInst *RecoverCall = nullptr;
   CGBuilderTy Builder(*this, AllocaInsertPt);
   if (auto *ParentAlloca = dyn_cast<llvm::AllocaInst>(ParentVar.getPointer())) {
@@ -1548,27 +1549,32 @@ void CodeGenFunction::EmitCapturedLocals(CodeGenFunction &ParentCGF,
     return;
   }
 
-  llvm::Value *EntryEBP = nullptr;
-  llvm::Value *ParentFP;
+  llvm::Value *EntryFP = nullptr;
+  CGBuilderTy Builder(CGM, AllocaInsertPt);
   if (IsFilter && CGM.getTarget().getTriple().getArch() == llvm::Triple::x86) {
     // 32-bit SEH filters need to be careful about FP recovery.  The end of the
     // EH registration is passed in as the EBP physical register.  We can
-    // recover that with llvm.frameaddress(1), and adjust that to recover the
-    // parent's true frame pointer.
-    CGBuilderTy Builder(CGM, AllocaInsertPt);
-    EntryEBP = Builder.CreateCall(
+    // recover that with llvm.frameaddress(1).
+    EntryFP = Builder.CreateCall(
         CGM.getIntrinsic(llvm::Intrinsic::frameaddress), {Builder.getInt32(1)});
-    llvm::Function *RecoverFPIntrin =
-        CGM.getIntrinsic(llvm::Intrinsic::x86_seh_recoverfp);
-    llvm::Constant *ParentI8Fn =
-        llvm::ConstantExpr::getBitCast(ParentCGF.CurFn, Int8PtrTy);
-    ParentFP = Builder.CreateCall(RecoverFPIntrin, {ParentI8Fn, EntryEBP});
   } else {
     // Otherwise, for x64 and 32-bit finally functions, the parent FP is the
     // second parameter.
     auto AI = CurFn->arg_begin();
     ++AI;
-    ParentFP = &*AI;
+    EntryFP = &*AI;
+  }
+
+  llvm::Value *ParentFP = EntryFP;
+  if (IsFilter) {
+    // Given whatever FP the runtime provided us in EntryFP, recover the true
+    // frame pointer of the parent function. We only need to do this in filters,
+    // since finally funclets recover the parent FP for us.
+    llvm::Function *RecoverFPIntrin =
+        CGM.getIntrinsic(llvm::Intrinsic::x86_seh_recoverfp);
+    llvm::Constant *ParentI8Fn =
+        llvm::ConstantExpr::getBitCast(ParentCGF.CurFn, Int8PtrTy);
+    ParentFP = Builder.CreateCall(RecoverFPIntrin, {ParentI8Fn, EntryFP});
   }
 
   // Create llvm.localrecover calls for all captures.
@@ -1592,8 +1598,8 @@ void CodeGenFunction::EmitCapturedLocals(CodeGenFunction &ParentCGF,
       continue;
 
     Address ParentVar = I->second;
-    setAddrOfLocalVar(VD,
-                  recoverAddrOfEscapedLocal(ParentCGF, ParentVar, ParentFP));
+    setAddrOfLocalVar(
+        VD, recoverAddrOfEscapedLocal(ParentCGF, ParentVar, ParentFP));
   }
 
   if (Finder.SEHCodeSlot.isValid()) {
@@ -1602,7 +1608,7 @@ void CodeGenFunction::EmitCapturedLocals(CodeGenFunction &ParentCGF,
   }
 
   if (IsFilter)
-    EmitSEHExceptionCodeSave(ParentCGF, ParentFP, EntryEBP);
+    EmitSEHExceptionCodeSave(ParentCGF, ParentFP, EntryFP);
 }
 
 /// Arrange a function prototype that can be called by Windows exception
@@ -1718,7 +1724,7 @@ CodeGenFunction::GenerateSEHFinallyFunction(CodeGenFunction &ParentCGF,
 
 void CodeGenFunction::EmitSEHExceptionCodeSave(CodeGenFunction &ParentCGF,
                                                llvm::Value *ParentFP,
-                                               llvm::Value *EntryEBP) {
+                                               llvm::Value *EntryFP) {
   // Get the pointer to the EXCEPTION_POINTERS struct. This is returned by the
   // __exception_info intrinsic.
   if (CGM.getTarget().getTriple().getArch() != llvm::Triple::x86) {
@@ -1731,7 +1737,7 @@ void CodeGenFunction::EmitSEHExceptionCodeSave(CodeGenFunction &ParentCGF,
     // exception registration object. It contains 6 32-bit fields, and the info
     // pointer is stored in the second field. So, GEP 20 bytes backwards and
     // load the pointer.
-    SEHInfo = Builder.CreateConstInBoundsGEP1_32(Int8Ty, EntryEBP, -20);
+    SEHInfo = Builder.CreateConstInBoundsGEP1_32(Int8Ty, EntryFP, -20);
     SEHInfo = Builder.CreateBitCast(SEHInfo, Int8PtrTy->getPointerTo());
     SEHInfo = Builder.CreateAlignedLoad(Int8PtrTy, SEHInfo, getPointerAlign());
     SEHCodeSlotStack.push_back(recoverAddrOfEscapedLocal(