[CIR][CIRGen] Handle paren list init and get dtors right

Author: bcardosolopes

clang/include/clang/CIR/MissingFeatures.h

@@ -184,6 +184,7 @@ struct MissingFeatures {
   static bool deferredReplacements() { return false; }
   static bool shouldInstrumentFunction() { return false; }
   static bool xray() { return false; }
+  static bool flagLoad() { return false; }
 
   // Inline assembly
   static bool asmGoto() { return false; }

clang/lib/CIR/CodeGen/CIRGenClass.cpp

@@ -1236,6 +1236,30 @@ struct CallDtorDelete final : EHScopeStack::Cleanup {
 };
 } // namespace
 
+class DestroyField final : public EHScopeStack::Cleanup {
+  const FieldDecl *field;
+  CIRGenFunction::Destroyer *destroyer;
+  bool useEHCleanupForArray;
+
+public:
+  DestroyField(const FieldDecl *field, CIRGenFunction::Destroyer *destroyer,
+               bool useEHCleanupForArray)
+      : field(field), destroyer(destroyer),
+        useEHCleanupForArray(useEHCleanupForArray) {}
+
+  void Emit(CIRGenFunction &CGF, Flags flags) override {
+    // Find the address of the field.
+    Address thisValue = CGF.LoadCXXThisAddress();
+    QualType RecordTy = CGF.getContext().getTagDeclType(field->getParent());
+    LValue ThisLV = CGF.makeAddrLValue(thisValue, RecordTy);
+    LValue LV = CGF.buildLValueForField(ThisLV, field);
+    assert(LV.isSimple());
+
+    CGF.emitDestroy(LV.getAddress(), field->getType(), destroyer,
+                    flags.isForNormalCleanup() && useEHCleanupForArray);
+  }
+};
+
 /// Emit all code that comes at the end of class's destructor. This is to call
 /// destructors on members and base classes in reverse order of their
 /// construction.
@@ -1346,8 +1370,9 @@ void CIRGenFunction::EnterDtorCleanups(const CXXDestructorDecl *DD,
     if (RT && RT->getDecl()->isAnonymousStructOrUnion())
       continue;
 
-    [[maybe_unused]] CleanupKind cleanupKind = getCleanupKind(dtorKind);
-    llvm_unreachable("EHStack.pushCleanup<DestroyField>(...) NYI");
+    CleanupKind cleanupKind = getCleanupKind(dtorKind);
+    EHStack.pushCleanup<DestroyField>(
+        cleanupKind, Field, getDestroyer(dtorKind), cleanupKind & EHCleanup);
   }
 
   if (SanitizeFields)

clang/lib/CIR/CodeGen/CIRGenDecl.cpp

@@ -1247,3 +1247,22 @@ void CIRGenFunction::pushEHDestroy(QualType::DestructionKind dtorKind,
 
   pushDestroy(EHCleanup, addr, type, getDestroyer(dtorKind), true);
 }
+
+// Pushes a destroy and defers its deactivation until its
+// CleanupDeactivationScope is exited.
+void CIRGenFunction::pushDestroyAndDeferDeactivation(
+    QualType::DestructionKind dtorKind, Address addr, QualType type) {
+  assert(dtorKind && "cannot push destructor for trivial type");
+
+  CleanupKind cleanupKind = getCleanupKind(dtorKind);
+  pushDestroyAndDeferDeactivation(
+      cleanupKind, addr, type, getDestroyer(dtorKind), cleanupKind & EHCleanup);
+}
+
+void CIRGenFunction::pushDestroyAndDeferDeactivation(
+    CleanupKind cleanupKind, Address addr, QualType type, Destroyer *destroyer,
+    bool useEHCleanupForArray) {
+  assert(!MissingFeatures::flagLoad());
+  pushDestroy(cleanupKind, addr, type, destroyer, useEHCleanupForArray);
+  DeferredDeactivationCleanupStack.push_back({EHStack.stable_begin(), nullptr});
+}

clang/lib/CIR/CodeGen/CIRGenExprAgg.cpp

@@ -274,6 +274,7 @@ class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
   void VisitAbstractConditionalOperator(const AbstractConditionalOperator *E);
   void VisitChooseExpr(const ChooseExpr *E) { llvm_unreachable("NYI"); }
   void VisitInitListExpr(InitListExpr *E);
+  void VisitCXXParenListInitExpr(CXXParenListInitExpr *E);
   void VisitCXXParenListOrInitListExpr(Expr *ExprToVisit, ArrayRef<Expr *> Args,
                                        FieldDecl *InitializedFieldInUnion,
                                        Expr *ArrayFiller);
@@ -1194,6 +1195,12 @@ void AggExprEmitter::VisitBinCmp(const BinaryOperator *E) {
   // All done! The result is in the Dest slot.
 }
 
+void AggExprEmitter::VisitCXXParenListInitExpr(CXXParenListInitExpr *E) {
+  VisitCXXParenListOrInitListExpr(E, E->getInitExprs(),
+                                  E->getInitializedFieldInUnion(),
+                                  E->getArrayFiller());
+}
+
 void AggExprEmitter::VisitInitListExpr(InitListExpr *E) {
   // TODO(cir): use something like CGF.ErrorUnsupported
   if (E->hadArrayRangeDesignator())
@@ -1350,10 +1357,14 @@ void AggExprEmitter::VisitCXXParenListOrInitListExpr(
     // Push a destructor if necessary.
     // FIXME: if we have an array of structures, all explicitly
     // initialized, we can end up pushing a linear number of cleanups.
-    [[maybe_unused]] bool pushedCleanup = false;
     if (QualType::DestructionKind dtorKind =
             field->getType().isDestructedType()) {
-      llvm_unreachable("NYI");
+      assert(LV.isSimple());
+      if (dtorKind) {
+        CGF.pushDestroyAndDeferDeactivation(NormalAndEHCleanup, LV.getAddress(),
+                                            field->getType(),
+                                            CGF.getDestroyer(dtorKind), false);
+      }
     }
 
     // From LLVM codegen, maybe not useful for CIR:

clang/lib/CIR/CodeGen/CIRGenFunction.h

@@ -375,6 +375,20 @@ class CIRGenFunction : public CIRGenTypeCache {
   EHScopeStack EHStack;
   llvm::SmallVector<char, 256> LifetimeExtendedCleanupStack;
 
+  // A stack of cleanups which were added to EHStack but have to be deactivated
+  // later before being popped or emitted. These are usually deactivated on
+  // exiting a `CleanupDeactivationScope` scope. For instance, after a
+  // full-expr.
+  //
+  // These are specially useful for correctly emitting cleanups while
+  // encountering branches out of expression (through stmt-expr or coroutine
+  // suspensions).
+  struct DeferredDeactivateCleanup {
+    EHScopeStack::stable_iterator Cleanup;
+    mlir::Operation *DominatingIP;
+  };
+  llvm::SmallVector<DeferredDeactivateCleanup> DeferredDeactivationCleanupStack;
+
   /// A mapping from NRVO variables to the flags used to indicate
   /// when the NRVO has been applied to this variable.
   llvm::DenseMap<const VarDecl *, mlir::Value> NRVOFlags;
@@ -1811,6 +1825,11 @@ class CIRGenFunction : public CIRGenTypeCache {
                                       QualType elementType,
                                       CharUnits elementAlign,
                                       Destroyer *destroyer);
+  void pushDestroyAndDeferDeactivation(QualType::DestructionKind dtorKind,
+                                       Address addr, QualType type);
+  void pushDestroyAndDeferDeactivation(CleanupKind cleanupKind, Address addr,
+                                       QualType type, Destroyer *destroyer,
+                                       bool useEHCleanupForArray);
   void buildArrayDestroy(mlir::Value begin, mlir::Value end,
                          QualType elementType, CharUnits elementAlign,
                          Destroyer *destroyer, bool checkZeroLength,

clang/test/CIR/CodeGen/paren-list-init.cpp

@@ -0,0 +1,39 @@
+// RUN: %clang_cc1 -std=c++20 -triple aarch64-none-linux-android21 -Wno-unused-value -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+
+struct Vec {
+  Vec();
+  Vec(Vec&&);
+  ~Vec();
+};
+
+struct S1 {
+  Vec v;
+};
+
+// CIR-DAG: ![[VecType:.*]] = !cir.struct<struct "Vec" {!cir.int<u, 8>}>
+// CIR-DAG: ![[S1:.*]] = !cir.struct<struct "S1" {!cir.struct<struct "Vec" {!cir.int<u, 8>}>}>
+
+template <int I>
+void make1() {
+  Vec v;
+  S1((Vec&&) v);
+// CIR: cir.func linkonce_odr  @_Z5make1ILi0EEvv()
+// CIR:   %[[VEC:.*]] = cir.alloca ![[VecType]], !cir.ptr<![[VecType]]>
+// CIR:   cir.call @_ZN3VecC1Ev(%[[VEC]]) : (!cir.ptr<![[VecType]]>)
+// CIR:   cir.scope {
+// CIR:     %[[AGG_TMP:.*]] = cir.alloca ![[S1]], !cir.ptr<![[S1]]>, ["agg.tmp.ensured"]
+// CIR:     %[[FIELD:.*]] = cir.get_member %[[AGG_TMP]][0] {name = "v"} : !cir.ptr<![[S1]]> -> !cir.ptr<![[VecType]]>
+// CIR:     cir.call @_ZN3VecC1EOS_(%[[FIELD]], %[[VEC]]) : (!cir.ptr<![[VecType]]>, !cir.ptr<![[VecType]]>) -> ()
+// CIR:     cir.call @_ZN2S1D1Ev(%[[AGG_TMP]]) : (!cir.ptr<![[S1]]>) -> ()
+// CIR:     cir.call @_ZN3VecD1Ev(%[[FIELD]]) : (!cir.ptr<![[VecType]]>) -> ()
+// CIR:   }
+
+// FIXME: implement MissingFeatures::flagLoad(), do not emit this a second time.
+// CIR:   cir.call @_ZN3VecD1Ev(%[[VEC]]) : (!cir.ptr<![[VecType]]>) -> ()
+// CIR:   cir.return
+}
+
+void foo() {
+  make1<0>();
+}