From 90abedc4620a539830ea7777bceb13db82fb9d99 Mon Sep 17 00:00:00 2001
From: TB Schardl <neboat@mit.edu>
Date: Fri, 22 Nov 2024 08:34:19 -0500
Subject: [PATCH] [CGCilk] Fix code generation of normal cleanup destination
 slot around unassociated taskframes.

---
 clang/lib/CodeGen/CGCilk.cpp                  | 14 ++++-----
 clang/lib/CodeGen/CodeGenFunction.h           |  1 -
 .../Cilk/cilkscope-try-normal-cleanup.cpp     | 29 +++++++++++++++++++
 3 files changed, 35 insertions(+), 9 deletions(-)
 create mode 100644 clang/test/Cilk/cilkscope-try-normal-cleanup.cpp

diff --git a/clang/lib/CodeGen/CGCilk.cpp b/clang/lib/CodeGen/CGCilk.cpp
index 72a9faaf66e8..c29d82d7a9f0 100644
--- a/clang/lib/CodeGen/CGCilk.cpp
+++ b/clang/lib/CodeGen/CGCilk.cpp
@@ -347,6 +347,10 @@ CodeGenFunction::TaskFrameScope::TaskFrameScope(CodeGenFunction &CGF)
       CGF.CGM.getIntrinsic(llvm::Intrinsic::taskframe_create);
   TaskFrame = CGF.Builder.CreateCall(TaskFrameCreate);
 
+  // Make sure the normal cleanup dest slot is allocated before changing the
+  // alloca insertion point.
+  CGF.getNormalCleanupDestSlot();
+
   // Create a new alloca insertion point within the task frame.
   OldAllocaInsertPt = CGF.AllocaInsertPt;
   llvm::Value *Undef = llvm::UndefValue::get(CGF.Int32Ty);
@@ -360,8 +364,6 @@ CodeGenFunction::TaskFrameScope::TaskFrameScope(CodeGenFunction &CGF)
   CGF.ExceptionSlot = nullptr;
   OldEHSelectorSlot = CGF.EHSelectorSlot;
   CGF.EHSelectorSlot = nullptr;
-  OldNormalCleanupDest = CGF.NormalCleanupDest;
-  CGF.NormalCleanupDest = Address::invalid();
 
   CGF.pushFullExprCleanup<EndUnassocTaskFrame>(
       static_cast<CleanupKind>(NormalAndEHCleanup | LifetimeMarker | TaskExit),
@@ -375,7 +377,7 @@ CodeGenFunction::TaskFrameScope::~TaskFrameScope() {
     return;
 
   // Pop the taskframe.
-  CGF.PopCleanupBlock();
+  CGF.PopCleanupBlock(true);
 
   // Restore the alloca insertion point.
   {
@@ -389,7 +391,6 @@ CodeGenFunction::TaskFrameScope::~TaskFrameScope() {
   CGF.EHResumeBlock = OldEHResumeBlock;
   CGF.ExceptionSlot = OldExceptionSlot;
   CGF.EHSelectorSlot = OldEHSelectorSlot;
-  CGF.NormalCleanupDest = OldNormalCleanupDest;
 
   if (TempInvokeDest) {
     if (llvm::BasicBlock *InvokeDest = CGF.getInvokeDest()) {
@@ -475,16 +476,13 @@ void CodeGenFunction::EmitCilkScopeStmt(const CilkScopeStmt &S) {
                                                   TapirRTStart);
     }
     // Create a nested synced scope.
-    SyncedScopeRAII SyncedScp(*this);
-    PushSyncRegion()->addImplicitSync();
+    SyncRegionRAII SyncReg(*this);
     bool BodyIsCompoundStmt = isa<CompoundStmt>(S.getBody());
     if (BodyIsCompoundStmt)
       ScopeIsSynced = true;
 
     // Emit the spawned statement.
     EmitStmt(S.getBody());
-
-    PopSyncRegion();
   }
 
   // If this _Cilk_scope is outermost in the function, mark that CodeGen is no
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 678f373f99ab..86d2a38ddd1a 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -1638,7 +1638,6 @@ class CodeGenFunction : public CodeGenTypeCache {
     llvm::BasicBlock *OldEHResumeBlock = nullptr;
     llvm::Value *OldExceptionSlot = nullptr;
     llvm::AllocaInst *OldEHSelectorSlot = nullptr;
-    Address OldNormalCleanupDest = Address::invalid();
 
     // Taskframe created separately from detach.
     llvm::Value *TaskFrame = nullptr;
diff --git a/clang/test/Cilk/cilkscope-try-normal-cleanup.cpp b/clang/test/Cilk/cilkscope-try-normal-cleanup.cpp
new file mode 100644
index 000000000000..99c62bd0a2d3
--- /dev/null
+++ b/clang/test/Cilk/cilkscope-try-normal-cleanup.cpp
@@ -0,0 +1,29 @@
+// RUN: %clang_cc1 %s -x c++ -O1 -fcxx-exceptions -fexceptions -fopencilk -mllvm -use-opencilk-runtime-bc=false -mllvm -debug-abi-calls=true -verify -S -emit-llvm -o - | FileCheck %s
+// expected-no-diagnostics
+extern int maybe_throws(int);
+
+// CHECK-LABEL: _Z9function4v
+int function4()
+{
+  _Cilk_scope {
+    try {
+// CHECK: i32 @_Z12maybe_throwsi
+// CHECK-NEXT: to label %[[NORMAL:.+]] unwind label %[[LPAD:.+]]
+      maybe_throws(1);
+// CHECK: [[LPAD]]:
+// CHECK: invoke
+// CHECK-NECT: to label %[[NORMAL]] unwind label %[[LPAD1:.+]]
+      return 1;
+    } catch (...) {
+// CHECK: [[NORMAL]]:
+// CHECK-NEXT: %[[RETVAL:.+]] = phi i32
+// CHECK-DAG: [ 2, %[[LPAD]] ]
+// CHECK-DAG: [ 1, %entry ]
+// CHECK: ret i32 %[[RETVAL]]
+      return 2;
+    }
+  }
+// This return is unreachable.
+// CHECK-NOT: ret i32 3
+  return 3;
+}
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