Commit 3fe2be75 authored by Timm Bäder's avatar Timm Bäder
Browse files

[clang][Interp] Call destructors of local variables 

Differential Revision: https://reviews.llvm.org/D154581
parent 14b039c1

clang/lib/AST/Interp/Context.cpp

+9 −1
Original line number Diff line number Diff line
@@ -160,8 +160,16 @@ const llvm::fltSemantics &Context::getFloatSemantics(QualType T) const { 
bool Context::Run(State &Parent, const Function *Func, APValue &Result) {

  InterpState State(Parent, *P, Stk, *this);

  State.Current = new InterpFrame(State, Func, /*Caller=*/nullptr, {});

  if (Interpret(State, Result))

  if (Interpret(State, Result)) {

    assert(Stk.empty());

    return true;

  }



  // We explicitly delete our state here, so the Stk.clear() call

  // below doesn't violently free values the destructor would

  // otherwise access.

  State.~InterpState();



  Stk.clear();

  return false;

}

clang/lib/AST/Interp/Descriptor.cpp

+25 −34
Original line number Diff line number Diff line
@@ -40,6 +40,9 @@ static void moveTy(Block *, const std::byte *Src, std::byte *Dst, 
template <typename T>

static void ctorArrayTy(Block *, std::byte *Ptr, bool, bool, bool,

                        const Descriptor *D) {

  new (Ptr) InitMapPtr(std::nullopt);



  Ptr += sizeof(InitMapPtr);

  for (unsigned I = 0, NE = D->getNumElems(); I < NE; ++I) {

    new (&reinterpret_cast<T *>(Ptr)[I]) T();

  }
@@ -47,11 +50,11 @@ static void ctorArrayTy(Block *, std::byte *Ptr, bool, bool, bool, 


template <typename T>

static void dtorArrayTy(Block *, std::byte *Ptr, const Descriptor *D) {

  InitMap *IM = *reinterpret_cast<InitMap **>(Ptr);

  if (IM != (InitMap *)-1)

    free(IM);

  InitMapPtr &IMP = *reinterpret_cast<InitMapPtr *>(Ptr);



  Ptr += sizeof(InitMap *);

  if (IMP)

    IMP = std::nullopt;

  Ptr += sizeof(InitMapPtr);

  for (unsigned I = 0, NE = D->getNumElems(); I < NE; ++I) {

    reinterpret_cast<T *>(Ptr)[I].~T();

  }
@@ -209,7 +212,8 @@ static BlockMoveFn getMovePrim(PrimType Type) { 
}



static BlockCtorFn getCtorArrayPrim(PrimType Type) {

  COMPOSITE_TYPE_SWITCH(Type, return ctorArrayTy<T>, return nullptr);

  TYPE_SWITCH(Type, return ctorArrayTy<T>);

  llvm_unreachable("unknown Expr");

}



static BlockDtorFn getDtorArrayPrim(PrimType Type) {
@@ -218,7 +222,8 @@ static BlockDtorFn getDtorArrayPrim(PrimType Type) { 
}



static BlockMoveFn getMoveArrayPrim(PrimType Type) {

  COMPOSITE_TYPE_SWITCH(Type, return moveArrayTy<T>, return nullptr);

  TYPE_SWITCH(Type, return moveArrayTy<T>);

  llvm_unreachable("unknown Expr");

}



/// Primitives.
@@ -238,7 +243,7 @@ Descriptor::Descriptor(const DeclTy &D, PrimType Type, MetadataSize MD, 
                       bool IsMutable)

    : Source(D), ElemSize(primSize(Type)), Size(ElemSize * NumElems),

      MDSize(MD.value_or(0)),

      AllocSize(align(Size) + sizeof(InitMap *) + MDSize), IsConst(IsConst),

      AllocSize(align(Size) + sizeof(InitMapPtr) + MDSize), IsConst(IsConst),

      IsMutable(IsMutable), IsTemporary(IsTemporary), IsArray(true),

      CtorFn(getCtorArrayPrim(Type)), DtorFn(getDtorArrayPrim(Type)),

      MoveFn(getMoveArrayPrim(Type)) {
@@ -249,9 +254,10 @@ Descriptor::Descriptor(const DeclTy &D, PrimType Type, MetadataSize MD, 
Descriptor::Descriptor(const DeclTy &D, PrimType Type, bool IsTemporary,

                       UnknownSize)

    : Source(D), ElemSize(primSize(Type)), Size(UnknownSizeMark), MDSize(0),

      AllocSize(alignof(void *)), IsConst(true), IsMutable(false),

      IsTemporary(IsTemporary), IsArray(true), CtorFn(getCtorArrayPrim(Type)),

      DtorFn(getDtorArrayPrim(Type)), MoveFn(getMoveArrayPrim(Type)) {

      AllocSize(alignof(void *) + sizeof(InitMapPtr)), IsConst(true),

      IsMutable(false), IsTemporary(IsTemporary), IsArray(true),

      CtorFn(getCtorArrayPrim(Type)), DtorFn(getDtorArrayPrim(Type)),

      MoveFn(getMoveArrayPrim(Type)) {

  assert(Source && "Missing source");

}
@@ -272,10 +278,10 @@ Descriptor::Descriptor(const DeclTy &D, Descriptor *Elem, MetadataSize MD, 
Descriptor::Descriptor(const DeclTy &D, Descriptor *Elem, bool IsTemporary,

                       UnknownSize)

    : Source(D), ElemSize(Elem->getAllocSize() + sizeof(InlineDescriptor)),

      Size(UnknownSizeMark), MDSize(0), AllocSize(alignof(void *)),

      ElemDesc(Elem), IsConst(true), IsMutable(false), IsTemporary(IsTemporary),

      IsArray(true), CtorFn(ctorArrayDesc), DtorFn(dtorArrayDesc),

      MoveFn(moveArrayDesc) {

      Size(UnknownSizeMark), MDSize(0),

      AllocSize(alignof(void *) + sizeof(InitMapPtr)), ElemDesc(Elem),

      IsConst(true), IsMutable(false), IsTemporary(IsTemporary), IsArray(true),

      CtorFn(ctorArrayDesc), DtorFn(dtorArrayDesc), MoveFn(moveArrayDesc) {

  assert(Source && "Missing source");

}
@@ -314,21 +320,12 @@ SourceLocation Descriptor::getLocation() const { 
  llvm_unreachable("Invalid descriptor type");

}



InitMap::InitMap(unsigned N) : UninitFields(N) {

  std::fill_n(data(), (N + PER_FIELD - 1) / PER_FIELD, 0);

InitMap::InitMap(unsigned N)

    : UninitFields(N), Data(std::make_unique<T[]>(numFields(N))) {

  std::fill_n(data(), numFields(N), 0);

}



InitMap::T *InitMap::data() {

  auto *Start = reinterpret_cast<char *>(this) + align(sizeof(InitMap));

  return reinterpret_cast<T *>(Start);

}



const InitMap::T *InitMap::data() const {

  auto *Start = reinterpret_cast<const char *>(this) + align(sizeof(InitMap));

  return reinterpret_cast<const T *>(Start);

}



bool InitMap::initialize(unsigned I) {

bool InitMap::initializeElement(unsigned I) {

  unsigned Bucket = I / PER_FIELD;

  T Mask = T(1) << (I % PER_FIELD);

  if (!(data()[Bucket] & Mask)) {
@@ -338,13 +335,7 @@ bool InitMap::initialize(unsigned I) { 
  return UninitFields == 0;

}



bool InitMap::isInitialized(unsigned I) const {

bool InitMap::isElementInitialized(unsigned I) const {

  unsigned Bucket = I / PER_FIELD;

  return data()[Bucket] & (T(1) << (I % PER_FIELD));

}
 


InitMap *InitMap::allocate(unsigned N) {

  const size_t NumFields = ((N + PER_FIELD - 1) / PER_FIELD);

  const size_t Size = align(sizeof(InitMap)) + NumFields * PER_FIELD;

  return new (malloc(Size)) InitMap(N);

}

clang/lib/AST/Interp/Descriptor.h

+16 −14
Original line number Diff line number Diff line
@@ -20,10 +20,12 @@ namespace clang { 
namespace interp {

class Block;

class Record;

struct InitMap;

struct Descriptor;

enum PrimType : unsigned;



using DeclTy = llvm::PointerUnion<const Decl *, const Expr *>;

using InitMapPtr = std::optional<std::pair<bool, std::shared_ptr<InitMap>>>;



/// Invoked whenever a block is created. The constructor method fills in the

/// inline descriptors of all fields and array elements. It also initializes
@@ -193,9 +195,6 @@ public: 
};



/// Bitfield tracking the initialisation status of elements of primitive arrays.

/// A pointer to this is embedded at the end of all primitive arrays.

/// If the map was not yet created and nothing was initialized, the pointer to

/// this structure is 0. If the object was fully initialized, the pointer is -1.

struct InitMap final {

private:

  /// Type packing bits.
@@ -203,26 +202,29 @@ private: 
  /// Bits stored in a single field.

  static constexpr uint64_t PER_FIELD = sizeof(T) * CHAR_BIT;



public:

  /// Initializes the map with no fields set.

  InitMap(unsigned N);

  explicit InitMap(unsigned N);



private:

  friend class Pointer;



  /// Returns a pointer to storage.

  T *data();

  const T *data() const;

  T *data() { return Data.get(); }

  const T *data() const { return Data.get(); }



public:

  /// Initializes an element. Returns true when object if fully initialized.

  bool initialize(unsigned I);

  bool initializeElement(unsigned I);



  /// Checks if an element was initialized.

  bool isInitialized(unsigned I) const;

  bool isElementInitialized(unsigned I) const;



  /// Allocates a map holding N elements.

  static InitMap *allocate(unsigned N);



private:

  /// Number of fields initialized.

  static constexpr size_t numFields(unsigned N) {

    return (N + PER_FIELD - 1) / PER_FIELD;

  }

  /// Number of fields not initialized.

  unsigned UninitFields;

  std::unique_ptr<T[]> Data;

};



} // namespace interp

clang/lib/AST/Interp/EvalEmitter.cpp

+8 −0
Original line number Diff line number Diff line
@@ -25,6 +25,14 @@ EvalEmitter::EvalEmitter(Context &Ctx, Program &P, State &Parent, 
      new InterpFrame(S, /*Func=*/nullptr, /*Caller=*/nullptr, CodePtr());

}



EvalEmitter::~EvalEmitter() {

  for (auto &[K, V] : Locals) {

    Block *B = reinterpret_cast<Block *>(V.get());

    if (B->isInitialized())

      B->invokeDtor();

  }

}



llvm::Expected<bool> EvalEmitter::interpretExpr(const Expr *E) {

  if (this->visitExpr(E))

    return true;

clang/lib/AST/Interp/EvalEmitter.h

+1 −1
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ protected: 
  EvalEmitter(Context &Ctx, Program &P, State &Parent, InterpStack &Stk,

              APValue &Result);



  virtual ~EvalEmitter() {}

  virtual ~EvalEmitter();



  /// Define a label.

  void emitLabel(LabelTy Label);