Allow tracking of single-valued objects to be dynamic.
PiperOrigin-RevId: 502401836
diff --git a/lifetime_analysis/lifetime_analysis.cc b/lifetime_analysis/lifetime_analysis.cc
index 35af397..43d5dae 100644
--- a/lifetime_analysis/lifetime_analysis.cc
+++ b/lifetime_analysis/lifetime_analysis.cc
@@ -52,13 +52,15 @@
public:
TransferStmtVisitor(
ObjectRepository& object_repository, PointsToMap& points_to_map,
- LifetimeConstraints& constraints, const clang::FunctionDecl* func,
+ LifetimeConstraints& constraints, ObjectSet& single_valued_objects,
+ const clang::FunctionDecl* func,
const llvm::DenseMap<const clang::FunctionDecl*,
FunctionLifetimesOrError>& callee_lifetimes,
const DiagnosticReporter& diag_reporter)
: object_repository_(object_repository),
points_to_map_(points_to_map),
constraints_(constraints),
+ single_valued_objects_(single_valued_objects),
func_(func),
callee_lifetimes_(callee_lifetimes),
diag_reporter_(diag_reporter) {}
@@ -94,6 +96,7 @@
ObjectRepository& object_repository_;
PointsToMap& points_to_map_;
LifetimeConstraints& constraints_;
+ ObjectSet& single_valued_objects_;
const clang::FunctionDecl* func_;
const llvm::DenseMap<const clang::FunctionDecl*, FunctionLifetimesOrError>&
callee_lifetimes_;
@@ -289,7 +292,7 @@
void SetPointerPointsToSetRespectingTypes(
const Object* pointer, const ObjectSet& points_to,
PointsToMap& points_to_map, clang::ASTContext& ast_context,
- LifetimeConstraints& constraints,
+ LifetimeConstraints& constraints, const ObjectSet& single_valued_objects,
const ObjectRepository& object_repository) {
assert(pointer->Type()->isPointerType() ||
pointer->Type()->isReferenceType());
@@ -307,8 +310,7 @@
// TODO(veluca): explicitly splitting between "object values before an
// expression" and "object values after an expression" will likely make
// this whole kind of reasoning clearer and less error-prone.
- if (object_repository.GetObjectValueType(pointer) !=
- ObjectRepository::ObjectValueType::kSingleValued) {
+ if (!single_valued_objects.Contains(pointer)) {
// Descending in callees is handled at a higher level.
GenerateConstraintsForAssignmentNonRecursive(
original_points_to_set, {object},
@@ -324,12 +326,12 @@
void SetAllPointersPointsToSetRespectingTypes(
const ObjectSet& pointers, const ObjectSet& points_to,
PointsToMap& points_to_map, clang::ASTContext& ast_context,
- LifetimeConstraints& constraints,
+ LifetimeConstraints& constraints, const ObjectSet& single_valued_objects,
const ObjectRepository& object_repository) {
for (auto pointer : pointers) {
- SetPointerPointsToSetRespectingTypes(pointer, points_to, points_to_map,
- ast_context, constraints,
- object_repository);
+ SetPointerPointsToSetRespectingTypes(
+ pointer, points_to, points_to_map, ast_context, constraints,
+ single_valued_objects, object_repository);
}
}
@@ -383,6 +385,7 @@
const Object* arg_object, clang::QualType type,
const ValueLifetimes& value_lifetimes, PointsToMap& points_to_map,
ObjectRepository& object_repository, LifetimeConstraints& constraints,
+ ObjectSet& single_valued_objects,
const llvm::DenseMap<Lifetime, ObjectSet>& lifetime_to_object_set,
clang::ASTContext& ast_context) {
class Visitor : public LifetimeVisitor {
@@ -390,10 +393,11 @@
Visitor(ObjectRepository& object_repository, PointsToMap& points_to_map,
LifetimeConstraints& constraints,
const llvm::DenseMap<Lifetime, ObjectSet>& lifetime_to_object_set,
- clang::ASTContext& ast_context)
+ ObjectSet& single_valued_objects, clang::ASTContext& ast_context)
: object_repository_(object_repository),
points_to_map_(points_to_map),
constraints_(constraints),
+ single_valued_objects_(single_valued_objects),
lifetime_to_object_set_(lifetime_to_object_set),
ast_context_(ast_context) {}
@@ -429,7 +433,7 @@
}
SetAllPointersPointsToSetRespectingTypes(
objects, points_to, points_to_map_, ast_context_, constraints_,
- object_repository_);
+ single_valued_objects_, object_repository_);
if (!kUseConstraintBasedAnalysis) {
// This assertion may fail to be true when visiting the return value
// object, if its objects were created recursively.
@@ -453,11 +457,12 @@
ObjectRepository& object_repository_;
PointsToMap& points_to_map_;
LifetimeConstraints& constraints_;
+ ObjectSet& single_valued_objects_;
const llvm::DenseMap<Lifetime, ObjectSet>& lifetime_to_object_set_;
clang::ASTContext& ast_context_;
};
Visitor visitor(object_repository, points_to_map, constraints,
- lifetime_to_object_set, ast_context);
+ lifetime_to_object_set, single_valued_objects, ast_context);
VisitLifetimes({arg_object}, type,
ObjectLifetimes(arg_object->GetLifetime(), value_lifetimes),
visitor);
@@ -473,7 +478,7 @@
const clang::Expr* call, const std::vector<FunctionParameter>& fn_params,
const ValueLifetimes& return_lifetimes, ObjectRepository& object_repository,
PointsToMap& points_to_map, LifetimeConstraints& constraints,
- clang::ASTContext& ast_context) {
+ ObjectSet& single_valued_objects, clang::ASTContext& ast_context) {
// TODO(mboehme): The following description says what we _want_ to do, but
// this isn't what we actually do right now. Modify the code so that it
// corresponds to the description, then remove this TODO.
@@ -595,7 +600,8 @@
for (auto [type, param_lifetimes, arg_object] : fn_params) {
PropagateLifetimesToPointees(arg_object, type, param_lifetimes,
points_to_map, object_repository, constraints,
- lifetime_to_object_set, ast_context);
+ single_valued_objects, lifetime_to_object_set,
+ ast_context);
}
// Step 3: Determine points-to set for the return value.
@@ -604,7 +610,8 @@
const Object* init_object = object_repository.GetInitializedObject(call);
PropagateLifetimesToPointees(
init_object, call->getType(), return_lifetimes, points_to_map,
- object_repository, constraints, lifetime_to_object_set, ast_context);
+ object_repository, constraints, single_valued_objects,
+ lifetime_to_object_set, ast_context);
} else {
ObjectSet rval_points_to;
@@ -627,7 +634,8 @@
}
LifetimeLattice LifetimeAnalysis::initialElement() {
- return LifetimeLattice(object_repository_.InitialPointsToMap());
+ return LifetimeLattice(object_repository_.InitialPointsToMap(),
+ object_repository_.InitialSingleValuedObjects());
}
std::string LifetimeAnalysis::ToString(const LifetimeLattice& state) {
@@ -649,8 +657,8 @@
auto stmt = cfg_stmt->getStmt();
TransferStmtVisitor visitor(object_repository_, state.PointsTo(),
- state.Constraints(), func_, callee_lifetimes_,
- diag_reporter_);
+ state.Constraints(), state.SingleValuedObjects(),
+ func_, callee_lifetimes_, diag_reporter_);
if (std::optional<std::string> err =
visitor.Visit(const_cast<clang::Stmt*>(stmt))) {
state = LifetimeLattice(*err);
@@ -922,11 +930,11 @@
// only in very specific circumstances:
// - We need to know unambiguously what the LHS refers to, so that we
// know we're definitely writing to a particular object, and
- // - That destination object needs to be "single-valued" (it can't be
- // an array, for example).
+ // - That destination object needs to be "single-valued" (see docstring of
+ // LifetimeLattice::SingleValuedObjects for the definition of this
+ // term).
if (lhs_points_to.size() == 1 &&
- object_repository_.GetObjectValueType(*lhs_points_to.begin()) ==
- ObjectRepository::ObjectValueType::kSingleValued) {
+ single_valued_objects_.Contains(*lhs_points_to.begin())) {
// Replacing the points-to-set entirely does not generate any
// constraints.
points_to_map_.SetPointerPointsToSet(lhs_points_to, rhs_points_to);
@@ -1240,7 +1248,7 @@
std::optional<ObjectSet> single_call_points_to = TransferLifetimesForCall(
call, fn_params, callee_lifetimes.GetReturnLifetimes(),
object_repository_, points_to_map_, constraints_,
- callee->getASTContext());
+ single_valued_objects_, callee->getASTContext());
if (single_call_points_to) {
if (call_points_to) {
call_points_to.value().Add(std::move(single_call_points_to).value());
@@ -1307,7 +1315,7 @@
TransferLifetimesForCall(
construct_expr, fn_params,
ValueLifetimes::ForLifetimeLessType(constructor->getReturnType()),
- object_repository_, points_to_map_, constraints_,
+ object_repository_, points_to_map_, constraints_, single_valued_objects_,
constructor->getASTContext());
return std::nullopt;
}
