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// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_TORQUE_IMPLEMENTATION_VISITOR_H_
#define V8_TORQUE_IMPLEMENTATION_VISITOR_H_
#include <string>
#include "src/base/macros.h"
#include "src/torque/ast.h"
#include "src/torque/cfg.h"
#include "src/torque/declarations.h"
#include "src/torque/global-context.h"
#include "src/torque/type-oracle.h"
#include "src/torque/types.h"
#include "src/torque/utils.h"
namespace v8 {
namespace internal {
namespace torque {
template <typename T>
class Binding;
struct LocalValue;
// LocationReference is the representation of an l-value, so a value that might
// allow for assignment. For uniformity, this class can also represent
// unassignable temporaries. Assignable values fall in two categories:
// - stack ranges that represent mutable variables, including structs.
// - field or element access expressions that generate operator calls.
class LocationReference {
public:
// An assignable stack range.
static LocationReference VariableAccess(
VisitResult variable,
base::Optional<Binding<LocalValue>*> binding = base::nullopt) {
DCHECK(variable.IsOnStack());
LocationReference result;
result.variable_ = std::move(variable);
result.binding_ = binding;
return result;
}
// An unassignable value. {description} is only used for error messages.
static LocationReference Temporary(VisitResult temporary,
std::string description) {
LocationReference result;
result.temporary_ = std::move(temporary);
result.temporary_description_ = std::move(description);
return result;
}
// A heap reference, that is, a tagged value and an offset to encode an inner
// pointer.
static LocationReference HeapReference(VisitResult heap_reference) {
LocationReference result;
DCHECK(StructType::MatchUnaryGeneric(heap_reference.type(),
TypeOracle::GetReferenceGeneric()));
result.heap_reference_ = std::move(heap_reference);
return result;
}
// A reference to an array on the heap. That is, a tagged value, an offset to
// encode an inner pointer, and the number of elements.
static LocationReference HeapSlice(VisitResult heap_slice) {
LocationReference result;
DCHECK(StructType::MatchUnaryGeneric(heap_slice.type(),
TypeOracle::GetSliceGeneric()));
result.heap_slice_ = std::move(heap_slice);
return result;
}
static LocationReference ArrayAccess(VisitResult base, VisitResult offset) {
LocationReference result;
result.eval_function_ = std::string{"[]"};
result.assign_function_ = std::string{"[]="};
result.call_arguments_ = {base, offset};
return result;
}
static LocationReference FieldAccess(VisitResult object,
std::string fieldname) {
LocationReference result;
result.eval_function_ = "." + fieldname;
result.assign_function_ = "." + fieldname + "=";
result.call_arguments_ = {object};
return result;
}
bool IsConst() const { return temporary_.has_value(); }
bool IsVariableAccess() const { return variable_.has_value(); }
const VisitResult& variable() const {
DCHECK(IsVariableAccess());
return *variable_;
}
bool IsTemporary() const { return temporary_.has_value(); }
const VisitResult& temporary() const {
DCHECK(IsTemporary());
return *temporary_;
}
bool IsHeapReference() const { return heap_reference_.has_value(); }
const VisitResult& heap_reference() const {
DCHECK(IsHeapReference());
return *heap_reference_;
}
bool IsHeapSlice() const { return heap_slice_.has_value(); }
const VisitResult& heap_slice() const {
DCHECK(IsHeapSlice());
return *heap_slice_;
}
const Type* ReferencedType() const {
if (IsHeapReference()) {
return *StructType::MatchUnaryGeneric(heap_reference().type(),
TypeOracle::GetReferenceGeneric());
} else if (IsHeapSlice()) {
return *StructType::MatchUnaryGeneric(heap_slice().type(),
TypeOracle::GetSliceGeneric());
}
return GetVisitResult().type();
}
const VisitResult& GetVisitResult() const {
if (IsVariableAccess()) return variable();
if (IsHeapSlice()) return heap_slice();
DCHECK(IsTemporary());
return temporary();
}
// For error reporting.
const std::string& temporary_description() const {
DCHECK(IsTemporary());
return *temporary_description_;
}
bool IsCallAccess() const {
bool is_call_access = eval_function_.has_value();
DCHECK_EQ(is_call_access, assign_function_.has_value());
return is_call_access;
}
const VisitResultVector& call_arguments() const {
DCHECK(IsCallAccess());
return call_arguments_;
}
const std::string& eval_function() const {
DCHECK(IsCallAccess());
return *eval_function_;
}
const std::string& assign_function() const {
DCHECK(IsCallAccess());
return *assign_function_;
}
base::Optional<Binding<LocalValue>*> binding() const {
DCHECK(IsVariableAccess());
return binding_;
}
private:
base::Optional<VisitResult> variable_;
base::Optional<VisitResult> temporary_;
base::Optional<std::string> temporary_description_;
base::Optional<VisitResult> heap_reference_;
base::Optional<VisitResult> heap_slice_;
base::Optional<std::string> eval_function_;
base::Optional<std::string> assign_function_;
VisitResultVector call_arguments_;
base::Optional<Binding<LocalValue>*> binding_;
LocationReference() = default;
};
struct InitializerResults {
std::vector<Identifier*> names;
std::map<std::string, VisitResult> field_value_map;
};
template <class T>
class Binding;
template <class T>
class BindingsManager {
public:
base::Optional<Binding<T>*> TryLookup(const std::string& name) {
if (name.length() >= 2 && name[0] == '_' && name[1] != '_') {
Error("Trying to reference '", name, "' which is marked as unused.")
.Throw();
}
auto binding = current_bindings_[name];
if (binding) {
(*binding)->SetUsed();
}
return binding;
}
private:
friend class Binding<T>;
std::unordered_map<std::string, base::Optional<Binding<T>*>>
current_bindings_;
};
template <class T>
class Binding : public T {
public:
template <class... Args>
Binding(BindingsManager<T>* manager, const std::string& name, Args&&... args)
: T(std::forward<Args>(args)...),
manager_(manager),
name_(name),
previous_binding_(this),
used_(false),
written_(false) {
std::swap(previous_binding_, manager_->current_bindings_[name]);
}
template <class... Args>
Binding(BindingsManager<T>* manager, const Identifier* name, Args&&... args)
: Binding(manager, name->value, std::forward<Args>(args)...) {
declaration_position_ = name->pos;
}
~Binding() {
if (!used_ && !SkipLintCheck()) {
Lint(BindingTypeString(), "'", name_,
"' is never used. Prefix with '_' if this is intentional.")
.Position(declaration_position_);
}
if (CheckWritten() && !written_ && !SkipLintCheck()) {
Lint(BindingTypeString(), "'", name_,
"' is never assigned to. Use 'const' instead of 'let'.")
.Position(declaration_position_);
}
manager_->current_bindings_[name_] = previous_binding_;
}
std::string BindingTypeString() const;
bool CheckWritten() const;
const std::string& name() const { return name_; }
SourcePosition declaration_position() const { return declaration_position_; }
bool Used() const { return used_; }
void SetUsed() { used_ = true; }
bool Written() const { return written_; }
void SetWritten() { written_ = true; }
private:
bool SkipLintCheck() const { return name_.length() > 0 && name_[0] == '_'; }
BindingsManager<T>* manager_;
const std::string name_;
base::Optional<Binding*> previous_binding_;
SourcePosition declaration_position_ = CurrentSourcePosition::Get();
bool used_;
bool written_;
DISALLOW_COPY_AND_ASSIGN(Binding);
};
template <class T>
class BlockBindings {
public:
explicit BlockBindings(BindingsManager<T>* manager) : manager_(manager) {}
void Add(std::string name, T value, bool mark_as_used = false) {
ReportErrorIfAlreadyBound(name);
auto binding =
base::make_unique<Binding<T>>(manager_, name, std::move(value));
if (mark_as_used) binding->SetUsed();
bindings_.push_back(std::move(binding));
}
void Add(const Identifier* name, T value, bool mark_as_used = false) {
ReportErrorIfAlreadyBound(name->value);
auto binding =
base::make_unique<Binding<T>>(manager_, name, std::move(value));
if (mark_as_used) binding->SetUsed();
bindings_.push_back(std::move(binding));
}
std::vector<Binding<T>*> bindings() const {
std::vector<Binding<T>*> result;
result.reserve(bindings_.size());
for (auto& b : bindings_) {
result.push_back(b.get());
}
return result;
}
private:
void ReportErrorIfAlreadyBound(const std::string& name) {
for (const auto& binding : bindings_) {
if (binding->name() == name) {
ReportError(
"redeclaration of name \"", name,
"\" in the same block is illegal, previous declaration at: ",
binding->declaration_position());
}
}
}
BindingsManager<T>* manager_;
std::vector<std::unique_ptr<Binding<T>>> bindings_;
};
struct LocalValue {
bool is_const;
VisitResult value;
};
struct LocalLabel {
Block* block;
std::vector<const Type*> parameter_types;
explicit LocalLabel(Block* block,
std::vector<const Type*> parameter_types = {})
: block(block), parameter_types(std::move(parameter_types)) {}
};
template <>
inline std::string Binding<LocalValue>::BindingTypeString() const {
return "Variable ";
}
template <>
inline bool Binding<LocalValue>::CheckWritten() const {
// Do the check only for non-const variables and non struct types.
auto binding = *manager_->current_bindings_[name_];
return !binding->is_const && !binding->value.type()->IsStructType();
}
template <>
inline std::string Binding<LocalLabel>::BindingTypeString() const {
return "Label ";
}
template <>
inline bool Binding<LocalLabel>::CheckWritten() const {
return false;
}
struct Arguments {
VisitResultVector parameters;
std::vector<Binding<LocalLabel>*> labels;
};
// Determine if a callable should be considered as an overload.
bool IsCompatibleSignature(const Signature& sig, const TypeVector& types,
size_t label_count);
class ImplementationVisitor {
public:
void GenerateBuiltinDefinitions(const std::string& output_directory);
void GenerateClassFieldOffsets(const std::string& output_directory);
void GeneratePrintDefinitions(const std::string& output_directory);
void GenerateClassDefinitions(const std::string& output_directory);
void GenerateInstanceTypes(const std::string& output_directory);
void GenerateClassVerifiers(const std::string& output_directory);
void GenerateClassDebugReaders(const std::string& output_directory);
void GenerateExportedMacrosAssembler(const std::string& output_directory);
void GenerateCSATypes(const std::string& output_directory);
void GenerateCppForInternalClasses(const std::string& output_directory);
VisitResult Visit(Expression* expr);
const Type* Visit(Statement* stmt);
void CheckInitializersWellformed(
const std::string& aggregate_name,
const std::vector<Field>& aggregate_fields,
const std::vector<NameAndExpression>& initializers,
bool ignore_first_field = false);
InitializerResults VisitInitializerResults(
const ClassType* class_type,
const std::vector<NameAndExpression>& expressions);
void InitializeFieldFromSpread(VisitResult object, const Field& field,
const InitializerResults& initializer_results);
VisitResult AddVariableObjectSize(
VisitResult object_size, const ClassType* current_class,
const InitializerResults& initializer_results);
void InitializeClass(const ClassType* class_type, VisitResult allocate_result,
const InitializerResults& initializer_results);
VisitResult Visit(StructExpression* decl);
LocationReference GetLocationReference(Expression* location);
LocationReference GetLocationReference(IdentifierExpression* expr);
LocationReference GetLocationReference(DereferenceExpression* expr);
LocationReference GetLocationReference(FieldAccessExpression* expr);
LocationReference GetLocationReference(ElementAccessExpression* expr);
VisitResult GenerateFetchFromLocation(const LocationReference& reference);
VisitResult GetBuiltinCode(Builtin* builtin);
VisitResult Visit(LocationExpression* expr);
void VisitAllDeclarables();
void Visit(Declarable* delarable);
void Visit(TypeAlias* decl);
VisitResult InlineMacro(Macro* macro,
base::Optional<LocationReference> this_reference,
const std::vector<VisitResult>& arguments,
const std::vector<Block*> label_blocks);
void VisitMacroCommon(Macro* macro);
void Visit(ExternMacro* macro) {}
void Visit(TorqueMacro* macro);
void Visit(Method* macro);
void Visit(Builtin* builtin);
void Visit(NamespaceConstant* decl);
VisitResult Visit(CallExpression* expr, bool is_tail = false);
VisitResult Visit(CallMethodExpression* expr);
VisitResult Visit(IntrinsicCallExpression* intrinsic);
const Type* Visit(TailCallStatement* stmt);
VisitResult Visit(ConditionalExpression* expr);
VisitResult Visit(LogicalOrExpression* expr);
VisitResult Visit(LogicalAndExpression* expr);
VisitResult Visit(IncrementDecrementExpression* expr);
VisitResult Visit(AssignmentExpression* expr);
VisitResult Visit(StringLiteralExpression* expr);
VisitResult Visit(NumberLiteralExpression* expr);
VisitResult Visit(AssumeTypeImpossibleExpression* expr);
VisitResult Visit(TryLabelExpression* expr);
VisitResult Visit(StatementExpression* expr);
VisitResult Visit(NewExpression* expr);
VisitResult Visit(SpreadExpression* expr);
const Type* Visit(ReturnStatement* stmt);
const Type* Visit(GotoStatement* stmt);
const Type* Visit(IfStatement* stmt);
const Type* Visit(WhileStatement* stmt);
const Type* Visit(BreakStatement* stmt);
const Type* Visit(ContinueStatement* stmt);
const Type* Visit(ForLoopStatement* stmt);
const Type* Visit(VarDeclarationStatement* stmt);
const Type* Visit(VarDeclarationStatement* stmt,
BlockBindings<LocalValue>* block_bindings);
const Type* Visit(BlockStatement* block);
const Type* Visit(ExpressionStatement* stmt);
const Type* Visit(DebugStatement* stmt);
const Type* Visit(AssertStatement* stmt);
void BeginCSAFiles();
void EndCSAFiles();
void GenerateImplementation(const std::string& dir);
DECLARE_CONTEXTUAL_VARIABLE(ValueBindingsManager,
BindingsManager<LocalValue>);
DECLARE_CONTEXTUAL_VARIABLE(LabelBindingsManager,
BindingsManager<LocalLabel>);
DECLARE_CONTEXTUAL_VARIABLE(CurrentCallable, Callable*);
DECLARE_CONTEXTUAL_VARIABLE(CurrentFileStreams,
GlobalContext::PerFileStreams*);
DECLARE_CONTEXTUAL_VARIABLE(CurrentReturnValue, base::Optional<VisitResult>);
// A BindingsManagersScope has to be active for local bindings to be created.
// Shadowing an existing BindingsManagersScope by creating a new one hides all
// existing bindings while the additional BindingsManagersScope is active.
struct BindingsManagersScope {
ValueBindingsManager::Scope value_bindings_manager;
LabelBindingsManager::Scope label_bindings_manager;
};
void SetDryRun(bool is_dry_run) { is_dry_run_ = is_dry_run; }
private:
base::Optional<Block*> GetCatchBlock();
void GenerateCatchBlock(base::Optional<Block*> catch_block);
// {StackScope} records the stack height at creation time and reconstructs it
// when being destructed by emitting a {DeleteRangeInstruction}, except for
// the slots protected by {StackScope::Yield}. Calling {Yield(v)} deletes all
// slots above the initial stack height except for the slots of {v}, which are
// moved to form the only slots above the initial height and marks them to
// survive destruction of the {StackScope}. A typical pattern is the
// following:
//
// VisitResult result;
// {
// StackScope stack_scope(this);
// // ... create temporary slots ...
// result = stack_scope.Yield(surviving_slots);
// }
class StackScope {
public:
explicit StackScope(ImplementationVisitor* visitor) : visitor_(visitor) {
base_ = visitor_->assembler().CurrentStack().AboveTop();
}
VisitResult Yield(VisitResult result) {
DCHECK(!closed_);
closed_ = true;
if (!result.IsOnStack()) {
if (!visitor_->assembler().CurrentBlockIsComplete()) {
visitor_->assembler().DropTo(base_);
}
return result;
}
DCHECK_LE(base_, result.stack_range().begin());
DCHECK_LE(result.stack_range().end(),
visitor_->assembler().CurrentStack().AboveTop());
visitor_->assembler().DropTo(result.stack_range().end());
visitor_->assembler().DeleteRange(
StackRange{base_, result.stack_range().begin()});
base_ = visitor_->assembler().CurrentStack().AboveTop();
return VisitResult(result.type(), visitor_->assembler().TopRange(
result.stack_range().Size()));
}
void Close() {
DCHECK(!closed_);
closed_ = true;
if (!visitor_->assembler().CurrentBlockIsComplete()) {
visitor_->assembler().DropTo(base_);
}
}
~StackScope() {
if (closed_) {
DCHECK_IMPLIES(
!visitor_->assembler().CurrentBlockIsComplete(),
base_ == visitor_->assembler().CurrentStack().AboveTop());
} else {
Close();
}
}
private:
ImplementationVisitor* visitor_;
BottomOffset base_;
bool closed_ = false;
};
class BreakContinueActivator {
public:
BreakContinueActivator(Block* break_block, Block* continue_block)
: break_binding_{&LabelBindingsManager::Get(), kBreakLabelName,
LocalLabel{break_block}},
continue_binding_{&LabelBindingsManager::Get(), kContinueLabelName,
LocalLabel{continue_block}} {}
private:
Binding<LocalLabel> break_binding_;
Binding<LocalLabel> continue_binding_;
};
base::Optional<Binding<LocalValue>*> TryLookupLocalValue(
const std::string& name);
base::Optional<Binding<LocalLabel>*> TryLookupLabel(const std::string& name);
Binding<LocalLabel>* LookupLabel(const std::string& name);
Block* LookupSimpleLabel(const std::string& name);
template <class Container>
Callable* LookupCallable(const QualifiedName& name,
const Container& declaration_container,
const TypeVector& types,
const std::vector<Binding<LocalLabel>*>& labels,
const TypeVector& specialization_types,
bool silence_errors = false);
bool TestLookupCallable(const QualifiedName& name,
const TypeVector& parameter_types);
template <class Container>
Callable* LookupCallable(const QualifiedName& name,
const Container& declaration_container,
const Arguments& arguments,
const TypeVector& specialization_types);
Method* LookupMethod(const std::string& name,
const AggregateType* receiver_type,
const Arguments& arguments,
const TypeVector& specialization_types);
const Type* GetCommonType(const Type* left, const Type* right);
VisitResult GenerateCopy(const VisitResult& to_copy);
void GenerateAssignToLocation(const LocationReference& reference,
const VisitResult& assignment_value);
void AddCallParameter(Callable* callable, VisitResult parameter,
const Type* parameter_type,
std::vector<VisitResult>* converted_arguments,
StackRange* argument_range,
std::vector<std::string>* constexpr_arguments);
VisitResult GenerateCall(Callable* callable,
base::Optional<LocationReference> this_parameter,
Arguments parameters,
const TypeVector& specialization_types = {},
bool tail_call = false);
VisitResult GenerateCall(const QualifiedName& callable_name,
Arguments parameters,
const TypeVector& specialization_types = {},
bool tail_call = false);
VisitResult GenerateCall(std::string callable_name, Arguments parameters,
const TypeVector& specialization_types = {},
bool tail_call = false) {
return GenerateCall(QualifiedName(std::move(callable_name)),
std::move(parameters), specialization_types, tail_call);
}
VisitResult GeneratePointerCall(Expression* callee,
const Arguments& parameters, bool tail_call);
void GenerateBranch(const VisitResult& condition, Block* true_block,
Block* false_block);
VisitResult GenerateBoolConstant(bool constant);
void GenerateExpressionBranch(Expression* expression, Block* true_block,
Block* false_block);
void GenerateMacroFunctionDeclaration(std::ostream& o,
const std::string& macro_prefix,
Macro* macro);
std::vector<std::string> GenerateFunctionDeclaration(
std::ostream& o, const std::string& macro_prefix, const std::string& name,
const Signature& signature, const NameVector& parameter_names,
bool pass_code_assembler_state = true);
VisitResult GenerateImplicitConvert(const Type* destination_type,
VisitResult source);
StackRange GenerateLabelGoto(LocalLabel* label,
base::Optional<StackRange> arguments = {});
std::vector<Binding<LocalLabel>*> LabelsFromIdentifiers(
const std::vector<Identifier*>& names);
StackRange LowerParameter(const Type* type, const std::string& parameter_name,
Stack<std::string>* lowered_parameters);
void LowerLabelParameter(const Type* type, const std::string& parameter_name,
std::vector<std::string>* lowered_parameters);
std::string ExternalLabelName(const std::string& label_name);
std::string ExternalLabelParameterName(const std::string& label_name,
size_t i);
std::string ExternalParameterName(const std::string& name);
std::ostream& source_out() {
if (auto* streams = CurrentFileStreams::Get()) {
return streams->csa_ccfile;
}
return null_stream_;
}
std::ostream& header_out() {
if (auto* streams = CurrentFileStreams::Get()) {
return streams->csa_headerfile;
}
return null_stream_;
}
CfgAssembler& assembler() { return *assembler_; }
void SetReturnValue(VisitResult return_value) {
base::Optional<VisitResult>& current_return_value =
CurrentReturnValue::Get();
DCHECK_IMPLIES(current_return_value, *current_return_value == return_value);
current_return_value = std::move(return_value);
}
VisitResult GetAndClearReturnValue() {
VisitResult return_value = *CurrentReturnValue::Get();
CurrentReturnValue::Get() = base::nullopt;
return return_value;
}
void WriteFile(const std::string& file, const std::string& content) {
if (is_dry_run_) return;
ReplaceFileContentsIfDifferent(file, content);
}
base::Optional<CfgAssembler> assembler_;
NullOStream null_stream_;
bool is_dry_run_;
};
void ReportAllUnusedMacros();
} // namespace torque
} // namespace internal
} // namespace v8
#endif // V8_TORQUE_IMPLEMENTATION_VISITOR_H_