[clang] 43b4e5b - Use pushFullExprCleanup for deferred destroy (#88670)

[via cfe-commits]

Author: Utkarsh Saxena
Date: 2024-04-15T21:30:18+02:00
New Revision: 43b4e5b9bff1719a6d3628a3a805cfeb59adaf16

URL: https://github.com/llvm/llvm-project/commit/43b4e5b9bff1719a6d3628a3a805cfeb59adaf16
DIFF: https://github.com/llvm/llvm-project/commit/43b4e5b9bff1719a6d3628a3a805cfeb59adaf16.diff

LOG: Use pushFullExprCleanup for deferred destroy (#88670)

Instead of directly pushing the `Destroy`, we should use
`pushFullExprCleanup` which handles conditional branches.
This fixes a backend crash due to
89ba7e183e6e2c64370ed1b963e54c06352211db.

Added minimized crash reproducer.

Added: 
    

Modified: 
    clang/lib/CodeGen/CGDecl.cpp
    clang/test/CodeGenCXX/control-flow-in-stmt-expr.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 8bdafa7c569b08..3f05ebb561da57 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -2216,8 +2216,11 @@ void CodeGenFunction::pushDestroyAndDeferDeactivation(
 void CodeGenFunction::pushDestroyAndDeferDeactivation(
     CleanupKind cleanupKind, Address addr, QualType type, Destroyer *destroyer,
     bool useEHCleanupForArray) {
-  pushCleanupAndDeferDeactivation<DestroyObject>(
-      cleanupKind, addr, type, destroyer, useEHCleanupForArray);
+  llvm::Instruction *DominatingIP =
+      Builder.CreateFlagLoad(llvm::Constant::getNullValue(Int8PtrTy));
+  pushDestroy(cleanupKind, addr, type, destroyer, useEHCleanupForArray);
+  DeferredDeactivationCleanupStack.push_back(
+      {EHStack.stable_begin(), DominatingIP});
 }
 
 void CodeGenFunction::pushStackRestore(CleanupKind Kind, Address SPMem) {

diff  --git a/clang/test/CodeGenCXX/control-flow-in-stmt-expr.cpp b/clang/test/CodeGenCXX/control-flow-in-stmt-expr.cpp
index ffde1bd6a724d8..95deee8bb1f1f2 100644
--- a/clang/test/CodeGenCXX/control-flow-in-stmt-expr.cpp
+++ b/clang/test/CodeGenCXX/control-flow-in-stmt-expr.cpp
@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 --std=c++20 -triple x86_64-linux-gnu -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 --std=c++20 -fexceptions -triple x86_64-linux-gnu -emit-llvm %s -o - | FileCheck -check-prefixes=EH %s
+// RUN: %clang_cc1 --std=c++20 -triple x86_64-linux-gnu -emit-llvm %s -o - | FileCheck -check-prefixes=NOEH,CHECK %s
 
 struct Printy {
   Printy(const char *name) : name(name) {}
@@ -349,6 +350,34 @@ void NewArrayInit() {
   // CHECK-NEXT:    br label %return
 }
 
+void DestroyInConditionalCleanup() {
+  // EH-LABEL: DestroyInConditionalCleanupv()
+  // NOEH-LABEL: DestroyInConditionalCleanupv()
+  struct A {
+    A() {}
+    ~A() {}
+  };
+
+  struct Value {
+    Value(A) {}
+    ~Value() {}
+  };
+
+  struct V2 {
+    Value K;
+    Value V;
+  };
+  // Verify we use conditional cleanups.
+  (void)(foo() ? V2{A(), A()} : V2{A(), A()});
+  // NOEH:   cond.true:
+  // NOEH:      call void @_ZZ27DestroyInConditionalCleanupvEN1AC1Ev
+  // NOEH:      store ptr %{{.*}}, ptr %cond-cleanup.save
+
+  // EH:   cond.true:
+  // EH:        invoke void @_ZZ27DestroyInConditionalCleanupvEN1AC1Ev
+  // EH:        store ptr %{{.*}}, ptr %cond-cleanup.save
+}
+
 void ArrayInitWithContinue() {
   // CHECK-LABEL: @_Z21ArrayInitWithContinuev
   // Verify that we start to emit the array destructor.