================
@@ -4639,6 +4645,303 @@ class FunctionNoProtoType : public FunctionType, public
llvm::FoldingSetNode {
}
};
+//
------------------------------------------------------------------------------
+
+/// Represents an abstract function effect, using just an enumeration
describing
+/// its kind.
+class FunctionEffect {
+public:
+ /// Identifies the particular effect.
+ enum class Kind : uint8_t {
+ None = 0,
+ NonBlocking = 1,
+ NonAllocating = 2,
+ Blocking = 3,
+ Allocating = 4
+ };
+
+ /// Flags describing some behaviors of the effect.
+ using Flags = unsigned;
+ enum FlagBit : Flags {
+ // Can verification inspect callees' implementations? (e.g. nonblocking:
+ // yes, tcb+types: no). This also implies the need for 2nd-pass
+ // verification.
+ FE_InferrableOnCallees = 0x1,
+
+ // Language constructs which effects can diagnose as disallowed.
+ FE_ExcludeThrow = 0x2,
+ FE_ExcludeCatch = 0x4,
+ FE_ExcludeObjCMessageSend = 0x8,
+ FE_ExcludeStaticLocalVars = 0x10,
+ FE_ExcludeThreadLocalVars = 0x20
+ };
+
+private:
+ LLVM_PREFERRED_TYPE(Kind)
+ unsigned FKind : 3;
+
+ // Expansion: for hypothetical TCB+types, there could be one Kind for TCB,
+ // then ~16(?) bits "SubKind" to map to a specific named TCB. SubKind would
+ // be considered for uniqueness.
+
+public:
+ FunctionEffect() : FKind(unsigned(Kind::None)) {}
+
+ explicit FunctionEffect(Kind K) : FKind(unsigned(K)) {}
+
+ /// The kind of the effect.
+ Kind kind() const { return Kind(FKind); }
+
+ /// Return the opposite kind, for effects which have opposites.
+ Kind oppositeKind() const;
+
+ /// For serialization.
+ uint32_t toOpaqueInt32() const { return FKind; }
+ static FunctionEffect fromOpaqueInt32(uint32_t Value) {
+ return FunctionEffect(Kind(Value));
+ }
+
+ /// Flags describing some behaviors of the effect.
+ Flags flags() const {
+ switch (kind()) {
+ case Kind::NonBlocking:
+ return FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
+ FE_ExcludeObjCMessageSend | FE_ExcludeStaticLocalVars |
+ FE_ExcludeThreadLocalVars;
+ case Kind::NonAllocating:
+ // Same as NonBlocking, except without FE_ExcludeStaticLocalVars
+ return FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
+ FE_ExcludeObjCMessageSend | FE_ExcludeThreadLocalVars;
+ case Kind::Blocking:
+ case Kind::Allocating:
+ return 0;
+ case Kind::None:
+ break;
+ }
+ llvm_unreachable("unknown effect kind");
+ }
+
+ /// The description printed in diagnostics, e.g. 'nonblocking'.
+ StringRef name() const;
+
+ /// Return true if the effect is allowed to be inferred on the callee,
+ /// which is either a FunctionDecl or BlockDecl.
+ /// This is only used if the effect has FE_InferrableOnCallees flag set.
+ /// Example: This allows nonblocking(false) to prevent inference for the
+ /// function.
+ bool canInferOnFunction(const Decl &Callee) const;
+
+ // Return false for success. When true is returned for a direct call, then
the
+ // FE_InferrableOnCallees flag may trigger inference rather than an immediate
+ // diagnostic. Caller should be assumed to have the effect (it may not have
it
+ // explicitly when inferring).
+ bool shouldDiagnoseFunctionCall(bool Direct,
+ ArrayRef<FunctionEffect> CalleeFX) const;
+
+ friend bool operator==(const FunctionEffect &LHS, const FunctionEffect &RHS)
{
+ return LHS.FKind == RHS.FKind;
+ }
+ friend bool operator!=(const FunctionEffect &LHS, const FunctionEffect &RHS)
{
+ return !(LHS == RHS);
+ }
+ friend bool operator<(const FunctionEffect &LHS, const FunctionEffect &RHS) {
+ return LHS.FKind < RHS.FKind;
+ }
+};
+
+/// Wrap a function effect's condition expression in another struct so
+/// that FunctionProtoType's TrailingObjects can treat it separately.
+class FunctionEffectCondition {
+ Expr *Cond = nullptr; // if null, unconditional
+
+public:
+ FunctionEffectCondition() = default;
+ FunctionEffectCondition(Expr *E) : Cond(E) {} // implicit OK
+
+ Expr *expr() const { return Cond; }
+
+ bool operator==(const FunctionEffectCondition &RHS) const {
+ return Cond == RHS.Cond;
+ }
+};
+
+/// A FunctionEffect plus a potential boolean expression determining whether
+/// the effect is declared (e.g. nonblocking(expr)). Generally the condition
+/// expression when present, is dependent.
+struct FunctionEffectWithCondition {
+ FunctionEffect Effect;
+ FunctionEffectCondition Cond;
+
+ FunctionEffectWithCondition() = default;
+ FunctionEffectWithCondition(const FunctionEffect &E,
+ const FunctionEffectCondition &C)
+ : Effect(E), Cond(C) {}
+
+ /// Return a textual description of the effect, and its condition, if any.
+ std::string description() const;
+
+ friend bool operator<(const FunctionEffectWithCondition &LHS,
+ const FunctionEffectWithCondition &RHS) {
+ if (LHS.Effect < RHS.Effect)
+ return true;
+ if (RHS.Effect < LHS.Effect)
+ return false;
+ return LHS.Cond.expr() < RHS.Cond.expr();
+ }
+};
+
+/// Support iteration in parallel through a pair of FunctionEffect and
+/// FunctionEffectCondition containers.
+template <typename Container> class FunctionEffectIterator {
+ const Container &Outer;
+ size_t Idx;
+
+public:
+ FunctionEffectIterator(const Container &O, size_t I) : Outer(O), Idx(I) {}
+ bool operator==(const FunctionEffectIterator &Other) const {
+ return Idx == Other.Idx;
+ }
+ bool operator!=(const FunctionEffectIterator &Other) const {
+ return Idx != Other.Idx;
+ }
+
+ // prefix increment
+ FunctionEffectIterator operator++() {
+ ++Idx;
+ return *this;
+ }
+
+ FunctionEffectWithCondition operator*() const {
+ const bool HasConds = !Outer.Conditions.empty();
+ return FunctionEffectWithCondition{Outer.Effects[Idx],
+ HasConds ? Outer.Conditions[Idx]
+ : FunctionEffectCondition()};
+ }
+};
+
+/// An immutable set of FunctionEffects and possibly conditions attached to
+/// them. The effects and conditions reside in memory not managed by this
object
+/// (typically, trailing objects in FunctionProtoType, or borrowed references
+/// from a FunctionEffectSet).
+///
+/// Invariants:
+/// - there is never more than one instance of any given effect.
+/// - the array of conditions is either empty or has the same size as the
+/// array of effects.
+/// - some conditions may be null expressions; each condition pertains to
+/// the effect at the same array index.
+///
+/// Also, if there are any conditions, at least one of those expressions will
be
+/// dependent, but this is only asserted in the constructor of
+/// FunctionProtoType.
+///
+/// See also FunctionEffectSet, in Sema, which provides a mutable set.
+class FunctionEffectsRef {
+ // Restrict classes which can call the private constructor -- these friends
+ // all maintain the required invariants. FunctionEffectSet is generally the
+ // only way in which the arrays are created; FunctionProtoType will not
+ // reorder them.
+ friend FunctionProtoType;
+ friend FunctionEffectSet;
+
+ ArrayRef<FunctionEffect> Effects;
+ ArrayRef<FunctionEffectCondition> Conditions;
+
+ // The arrays are expected to have been sorted by the caller, with the
+ // effects in order. The conditions array must be empty or the same size
+ // as the effects array, since the conditions are associated with the effects
+ // at the same array indices.
+ FunctionEffectsRef(ArrayRef<FunctionEffect> FX,
+ ArrayRef<FunctionEffectCondition> Conds)
+ : Effects(FX), Conditions(Conds) {}
+
+public:
+ /// Extract the effects from a Type if it is a function, block, or member
+ /// function pointer, or a reference or pointer to one.
+ static FunctionEffectsRef get(QualType QT);
+
+ /// Asserts invariants.
+ static FunctionEffectsRef create(ArrayRef<FunctionEffect> FX,
+ ArrayRef<FunctionEffectCondition> Conds);
+
+ FunctionEffectsRef() = default;
+
+ bool empty() const { return Effects.empty(); }
+ size_t size() const { return Effects.size(); }
+
+ ArrayRef<FunctionEffect> effects() const { return Effects; }
+ ArrayRef<FunctionEffectCondition> conditions() const { return Conditions; }
+
+ using iterator = FunctionEffectIterator<FunctionEffectsRef>;
+ friend iterator;
+ iterator begin() const { return iterator(*this, 0); }
+ iterator end() const { return iterator(*this, size()); }
+
+ friend bool operator==(const FunctionEffectsRef &LHS,
+ const FunctionEffectsRef &RHS) {
+ return LHS.Effects == RHS.Effects && LHS.Conditions == RHS.Conditions;
+ }
+ friend bool operator!=(const FunctionEffectsRef &LHS,
+ const FunctionEffectsRef &RHS) {
+ return !(LHS == RHS);
+ }
+
+ void Profile(llvm::FoldingSetNodeID &ID) const;
+ void dump(llvm::raw_ostream &OS) const;
+};
+
+/// A mutable set of FunctionEffects and possibly conditions attached to them.
+/// Used to compare and merge effects on declarations.
+///
+/// Has the same invariants as FunctionEffectsRef.
+class FunctionEffectSet {
+ SmallVector<FunctionEffect> Effects;
+ SmallVector<FunctionEffectCondition> Conditions;
+
+public:
+ FunctionEffectSet() = default;
+
+ explicit FunctionEffectSet(const FunctionEffectsRef &FX)
+ : Effects(FX.effects()), Conditions(FX.conditions()) {}
+
+ bool empty() const { return Effects.empty(); }
+ size_t size() const { return Effects.size(); }
+
+ using iterator = FunctionEffectIterator<FunctionEffectSet>;
+ friend iterator;
+ iterator begin() const { return iterator(*this, 0); }
+ iterator end() const { return iterator(*this, size()); }
+
+ operator FunctionEffectsRef() const { return {Effects, Conditions}; }
+
+ void dump(llvm::raw_ostream &OS) const;
+
+ // Mutators
+
+ // On insertion, a conflict occurs when attempting to insert an
+ // effect which is opposite an effect already in the set, or attempting
+ // to insert an effect which is already in the set but with a condition
+ // which is not identical.
+ struct Conflict {
+ FunctionEffectWithCondition Kept;
+ FunctionEffectWithCondition Rejected;
+ };
+ using Conflicts = SmallVector<Conflict>;
+
+ void insert(const FunctionEffectWithCondition &NewEC, Conflicts &Errs);
+ void insert(const FunctionEffectsRef &Set, Conflicts &Errs);
+ void insertIgnoringConditions(const FunctionEffectsRef &Set, Conflicts
&Errs);
+
+ void replaceItem(unsigned Idx, const FunctionEffectWithCondition &Item);
+ void erase(unsigned Idx);
----------------
dougsonos wrote:
Thanks! That works.
https://github.com/llvm/llvm-project/pull/84983
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