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[clang][Interp] Fix activating via indirect field initializers #102753

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Merged
merged 1 commit into from
Aug 10, 2024
Merged

[clang][Interp] Fix activating via indirect field initializers #102753

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14 changes: 5 additions & 9 deletions clang/lib/AST/Interp/Compiler.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4737,8 +4737,7 @@ bool Compiler<Emitter>::visitFunc(const FunctionDecl *F) {
// Classify the return type.
ReturnType = this->classify(F->getReturnType());

auto emitFieldInitializer = [&](const Record *R, const Record::Field *F,
unsigned FieldOffset,
auto emitFieldInitializer = [&](const Record::Field *F, unsigned FieldOffset,
const Expr *InitExpr) -> bool {
// We don't know what to do with these, so just return false.
if (InitExpr->getType().isNull())
Expand All @@ -4750,8 +4749,6 @@ bool Compiler<Emitter>::visitFunc(const FunctionDecl *F) {

if (F->isBitField())
return this->emitInitThisBitField(*T, F, FieldOffset, InitExpr);
if (R->isUnion())
return this->emitInitThisFieldActive(*T, FieldOffset, InitExpr);
return this->emitInitThisField(*T, FieldOffset, InitExpr);
}
// Non-primitive case. Get a pointer to the field-to-initialize
Expand Down Expand Up @@ -4787,7 +4784,7 @@ bool Compiler<Emitter>::visitFunc(const FunctionDecl *F) {
if (const FieldDecl *Member = Init->getMember()) {
const Record::Field *F = R->getField(Member);

if (!emitFieldInitializer(R, F, F->Offset, InitExpr))
if (!emitFieldInitializer(F, F->Offset, InitExpr))
return false;
} else if (const Type *Base = Init->getBaseClass()) {
const auto *BaseDecl = Base->getAsCXXRecordDecl();
Expand Down Expand Up @@ -4815,11 +4812,11 @@ bool Compiler<Emitter>::visitFunc(const FunctionDecl *F) {
assert(IFD->getChainingSize() >= 2);

unsigned NestedFieldOffset = 0;
const Record *FieldRecord = nullptr;
const Record::Field *NestedField = nullptr;
for (const NamedDecl *ND : IFD->chain()) {
const auto *FD = cast<FieldDecl>(ND);
FieldRecord = this->P.getOrCreateRecord(FD->getParent());
const Record *FieldRecord =
this->P.getOrCreateRecord(FD->getParent());
assert(FieldRecord);

NestedField = FieldRecord->getField(FD);
Expand All @@ -4829,8 +4826,7 @@ bool Compiler<Emitter>::visitFunc(const FunctionDecl *F) {
}
assert(NestedField);

if (!emitFieldInitializer(FieldRecord, NestedField, NestedFieldOffset,
InitExpr))
if (!emitFieldInitializer(NestedField, NestedFieldOffset, InitExpr))
return false;
} else {
assert(Init->isDelegatingInitializer());
Expand Down
26 changes: 1 addition & 25 deletions clang/lib/AST/Interp/Interp.h
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Expand Up @@ -1391,6 +1391,7 @@ bool InitThisField(InterpState &S, CodePtr OpPC, uint32_t I) {
return false;
const Pointer &Field = This.atField(I);
Field.deref<T>() = S.Stk.pop<T>();
Field.activate();
Field.initialize();
return true;
}
Expand All @@ -1413,20 +1414,6 @@ bool InitThisBitField(InterpState &S, CodePtr OpPC, const Record::Field *F,
return true;
}

template <PrimType Name, class T = typename PrimConv<Name>::T>
bool InitThisFieldActive(InterpState &S, CodePtr OpPC, uint32_t I) {
if (S.checkingPotentialConstantExpression())
return false;
const Pointer &This = S.Current->getThis();
if (!CheckThis(S, OpPC, This))
return false;
const Pointer &Field = This.atField(I);
Field.deref<T>() = S.Stk.pop<T>();
Field.activate();
Field.initialize();
return true;
}

/// 1) Pops the value from the stack
/// 2) Peeks a pointer from the stack
/// 3) Pushes the value to field I of the pointer on the stack
Expand All @@ -1451,17 +1438,6 @@ bool InitBitField(InterpState &S, CodePtr OpPC, const Record::Field *F) {
return true;
}

template <PrimType Name, class T = typename PrimConv<Name>::T>
bool InitFieldActive(InterpState &S, CodePtr OpPC, uint32_t I) {
const T &Value = S.Stk.pop<T>();
const Pointer &Ptr = S.Stk.pop<Pointer>();
const Pointer &Field = Ptr.atField(I);
Field.deref<T>() = Value;
Field.activate();
Field.initialize();
return true;
}

//===----------------------------------------------------------------------===//
// GetPtr Local/Param/Global/Field/This
//===----------------------------------------------------------------------===//
Expand Down
4 changes: 0 additions & 4 deletions clang/lib/AST/Interp/Opcodes.td
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Expand Up @@ -440,8 +440,6 @@ def SetThisField : AccessOpcode;
// [Value] -> []
def InitThisField : AccessOpcode;
// [Value] -> []
def InitThisFieldActive : AccessOpcode;
// [Value] -> []
def InitThisBitField : Opcode {
let Types = [AluTypeClass];
let Args = [ArgRecordField, ArgUint32];
Expand All @@ -451,8 +449,6 @@ def InitThisBitField : Opcode {
def InitField : AccessOpcode;
// [Pointer, Value] -> []
def InitBitField : BitFieldOpcode;
// [Pointer, Value] -> []
def InitFieldActive : AccessOpcode;

//===----------------------------------------------------------------------===//
// Pointer access
Expand Down
41 changes: 41 additions & 0 deletions clang/test/AST/Interp/unions.cpp
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Expand Up @@ -306,4 +306,45 @@ namespace Zeroing {
static_assert(UnionWithUnnamedBitfield{}.n == 0, "");
static_assert(UnionWithUnnamedBitfield{1}.n == 1, "");
}

namespace IndirectField {
struct S {
struct {
union {
struct {
int a;
int b;
};
int c;
};
int d;
};
union {
int e;
int f;
};
constexpr S(int a, int b, int d, int e) : a(a), b(b), d(d), e(e) {}
constexpr S(int c, int d, int f) : c(c), d(d), f(f) {}
};

constexpr S s1(1,2,3,4);
constexpr S s2(5, 6, 7);

static_assert(s1.a == 1, "");
static_assert(s1.b == 2, "");

static_assert(s1.c == 0, ""); // both-error {{constant expression}} both-note {{union with active member}}
static_assert(s1.d == 3, "");
static_assert(s1.e == 4, "");
static_assert(s1.f == 0, ""); // both-error {{constant expression}} both-note {{union with active member}}

static_assert(s2.a == 0, ""); // both-error {{constant expression}} both-note {{union with active member}}
static_assert(s2.b == 0, ""); // both-error {{constant expression}} both-note {{union with active member}}
static_assert(s2.c == 5, "");
static_assert(s2.d == 6, "");
static_assert(s2.e == 0, ""); // both-error {{constant expression}} both-note {{union with active member}}
static_assert(s2.f == 7, "");
}


#endif
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