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[Cherry-pick][BoundsSafety][Sema] Allow counted_by and counted_by_or_null on pointers where the pointee type is incomplete but potentially completable #10514

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Merged
merged 1 commit into from
Apr 18, 2025
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[Cherry-pick][BoundsSafety][Sema] Allow counted_by and counted_by_or_null on pointers where the pointee type is incomplete but potentially completable #10514

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10 changes: 4 additions & 6 deletions clang/include/clang/AST/Type.h
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Original file line number Diff line number Diff line change
Expand Up @@ -2479,6 +2479,7 @@ class alignas(TypeAlignment) Type : public ExtQualsTypeCommonBase {
bool isIncompleteOrSizelessType() const {
return isIncompleteType() || isSizelessType() || isFunctionType();
}
/* TO_UPSTREAM(BoundsSafety) OFF*/

/// \returns True if the type is incomplete and it is also a type that
/// cannot be completed by a later type definition.
Expand All @@ -2495,11 +2496,10 @@ class alignas(TypeAlignment) Type : public ExtQualsTypeCommonBase {
/// // This decl has type 'char[]' which is incomplete and cannot be later
/// // completed by another by another type declaration.
/// extern char foo[];
/// // This decl how has complete type 'char[5]'.
/// // This decl now has complete type 'char[5]'.
/// char foo[5]; // foo has a complete type
/// \endcode
bool isIncompletableIncompleteType() const;
/* TO_UPSTREAM(BoundsSafety) OFF*/
bool isAlwaysIncompleteType() const;

/// Determine whether this type is an object type.
bool isObjectType() const {
Expand Down Expand Up @@ -3690,9 +3690,7 @@ class CountAttributedType final
return T->getTypeClass() == CountAttributed;
}

/* TO_UPSTREAM(BoundsSafety) ON*/
StringRef GetAttributeName(bool WithMacroPrefix) const;
/* TO_UPSTREAM(BoundsSafety) OFF*/
StringRef getAttributeName(bool WithMacroPrefix) const;
};

/* TO_UPSTREAM(BoundsSafety) ON */
Expand Down
27 changes: 25 additions & 2 deletions clang/include/clang/Basic/DiagnosticSemaKinds.td
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Expand Up @@ -6790,6 +6790,30 @@ def err_counted_by_attr_pointee_unknown_size : Error<
"%select{|. This will be an error in a future compiler version}3"
""
"}2">;
def err_counted_by_on_incomplete_type_on_assign : Error <
"cannot %select{"
"assign to %select{object|'%1'}2 with|" // AA_Assigning,
"pass argument to %select{parameter|parameter '%1'}2 with|" // AA_Passing,
"return|" // AA_Returning,
"convert to|" // AA_Converting (UNUSED)
"%select{|implicitly }3initialize %select{object|'%1'}2 with|" // AA_Initializing,
"pass argument to parameter with|" // AA_Sending (UNUSED)
"cast to|" // AA_Casting (UNUSED)
"pass argument to parameter with" // AA_Passing_CFAudited (UNUSED)
"}0 '%5' attributed type %4 because the pointee type %6 is incomplete">;

def err_counted_by_on_incomplete_type_on_use : Error <
"cannot %select{"
"use '%1' with '%4' attributed|" // Generic expr
"call '%1' with '%4' attributed return" // CallExpr
"}0 type %2 because the pointee type %3 is incomplete">;

def note_counted_by_consider_completing_pointee_ty : Note<
"consider providing a complete definition for %0">;

def note_counted_by_consider_using_sized_by : Note<
"consider using '__sized_by%select{|_or_null}0' instead of "
"'__counted_by%select{|_or_null}0'">;

def warn_counted_by_attr_elt_type_unknown_size :
Warning<err_counted_by_attr_pointee_unknown_size.Summary>,
Expand Down Expand Up @@ -12895,8 +12919,7 @@ def err_bounds_safety_counted_by_on_incomplete_type_on_func_def : Error<
" '%3'" // named parameter
"}2 with"
"}1 type %4 on a function definition because the pointee type %5 is "
"incomplete; consider providing a complete definition for %5 before the "
"function body or using the '__sized_by%select{|_or_null}6' attribute"
"incomplete"
>;

def err_bounds_safety_counted_by_on_incomplete_type_on_var_decl : Error<
Expand Down
40 changes: 9 additions & 31 deletions clang/include/clang/Sema/Sema.h
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Expand Up @@ -2263,7 +2263,6 @@ class Sema final : public SemaBase {
bool CheckCountedByAttrOnField(FieldDecl *FD, Expr *E, bool CountInBytes,
bool OrNull);

/* TO_UPSTREAM(BoundsSafety) ON*/
/// Perform Bounds Safety Semantic checks for assigning to a `__counted_by` or
/// `__counted_by_or_null` pointer type \param LHSTy.
///
Expand All @@ -2285,28 +2284,6 @@ class Sema final : public SemaBase {
SourceLocation Loc, const ValueDecl *Assignee,
bool ShowFullyQualifiedAssigneeName);

/// Perform Checks for assigning to a `__counted_by` or
/// `__counted_by_or_null` pointer type \param LHSTy where the pointee type
/// is incomplete which is invalid.
///
/// \param LHSTy The type being assigned to. Checks will only be performed if
/// the type is a `counted_by` or `counted_by_or_null ` pointer.
/// \param RHSExpr The expression being assigned from.
/// \param Action The type assignment being performed
/// \param Loc The SourceLocation to use for error diagnostics
/// \param Assignee The ValueDecl being assigned. This is used to compute
/// the name of the assignee. If the assignee isn't known this can
/// be set to nullptr.
/// \param ShowFullyQualifiedAssigneeName If set to true when using \p
/// Assignee to compute the name of the assignee use the fully
/// qualified name, otherwise use the unqualified name.
///
/// \returns True iff no diagnostic where emitted, false otherwise.
bool BoundsSafetyCheckAssignmentToCountAttrPtrWithIncompletePointeeTy(
QualType LHSTy, Expr *RHSExpr, AssignmentAction Action,
SourceLocation Loc, const ValueDecl *Assignee,
bool ShowFullyQualifiedAssigneeName);

/// Perform Bounds Safety Semantic checks for initializing a Bounds Safety
/// pointer.
///
Expand All @@ -2323,6 +2300,15 @@ class Sema final : public SemaBase {
AssignmentAction Action,
QualType LHSType, Expr *RHSExpr);

/// Perform Bounds Safety semantic checks for uses of invalid uses counted_by
/// or counted_by_or_null pointers in \param E.
///
/// \param E the expression to check
///
/// \returns True iff no diagnostic where emitted, false otherwise.
bool BoundsSafetyCheckUseOfCountAttrPtr(const Expr *E);

/* TO_UPSTREAM(BoundsSafety) ON*/
/// Perform Bounds Safety semantic checks on function parameters on a function
/// definition. This only performs checks that can be made by looking at
/// \param PVD in isolation (i.e. not looking at other parameters in the
Expand Down Expand Up @@ -2351,14 +2337,6 @@ class Sema final : public SemaBase {
/// \returns True iff no diagnostic where emitted, false otherwise.
bool BoundsSafetyCheckReturnTyForFunctionDef(FunctionDecl *FD);

/// Perform Bounds Safety semantic checks for uses of invalid uses counted_by
/// or counted_by_or_null pointers in \param E.
///
/// \param E the expression to check
///
/// \returns True iff no diagnostic where emitted, false otherwise.
bool BoundsSafetyCheckUseOfCountAttrPtr(Expr *E);

/// Perform Bounds Safety semantic checks on variable declaration \param VD.
///
/// \param VD The VarDecl to check
Expand Down
40 changes: 22 additions & 18 deletions clang/lib/AST/Type.cpp
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Expand Up @@ -2591,6 +2591,22 @@ bool Type::isIncompleteType(NamedDecl **Def) const {
}
}

bool Type::isAlwaysIncompleteType() const {
if (!isIncompleteType())
return false;

// Forward declarations of structs, classes, enums, and unions could be later
// completed in a compilation unit by providing a type definition.
if (getAsTagDecl())
return false;

// Other types are incompletable.
//
// E.g. `char[]` and `void`. The type is incomplete and no future
// type declarations can make the type complete.
return true;
}

bool Type::isSizelessBuiltinType() const {
if (isSizelessVectorType())
return true;
Expand Down Expand Up @@ -2708,22 +2724,6 @@ bool Type::isSizeMeaningless() const {
return true;
return false;
}

bool Type::isIncompletableIncompleteType() const {
if (!isIncompleteType())
return false;

// Forward declarations of structs, classes, enums, and unions could be later
// completed in a compilation unit by providing a definition.
if (isStructureOrClassType() || isEnumeralType() || isUnionType())
return false;

// Other types are incompletable.
//
// E.g. `char[]` and `void`. The type is incomplete and no future
// type declarations can make the type complete.
return true;
}
/* TO_UPSTREAM(BoundsSafety) OFF*/

QualType Type::getSizelessVectorEltType(const ASTContext &Ctx) const {
Expand Down Expand Up @@ -4072,8 +4072,11 @@ CountAttributedType::CountAttributedType(
DeclSlot[i] = CoupledDecls[i];
}

/* TO_UPSTREAM(BoundsSafety) ON*/
StringRef CountAttributedType::GetAttributeName(bool WithMacroPrefix) const {
StringRef CountAttributedType::getAttributeName(bool WithMacroPrefix) const {
// TODO: This method isn't really ideal because it doesn't return the spelling
// of the attribute that was used in the user's code. This method is used for
// diagnostics so the fact it doesn't use the spelling of the attribute in
// the user's code could be confusing (#113585).
#define ENUMERATE_ATTRS(PREFIX) \
do { \
if (isCountInBytes()) { \
Expand All @@ -4094,6 +4097,7 @@ StringRef CountAttributedType::GetAttributeName(bool WithMacroPrefix) const {
#undef ENUMERATE_ATTRS
}

/* TO_UPSTREAM(BoundsSafety) ON*/
DynamicRangePointerType::DynamicRangePointerType(
QualType PointerTy, QualType CanPointerTy, Expr *StartPtr, Expr *EndPtr,
ArrayRef<TypeCoupledDeclRefInfo> StartPtrDecls,
Expand Down
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