mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 22:02:23 +01:00
1183 lines
44 KiB
C++
1183 lines
44 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
|
|
// Exceptions. See /LICENSE for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
|
|
#include "executable_semantics/interpreter/interpreter.h"
|
|
|
|
#include <iterator>
|
|
#include <map>
|
|
#include <optional>
|
|
#include <utility>
|
|
#include <variant>
|
|
#include <vector>
|
|
|
|
#include "common/check.h"
|
|
#include "executable_semantics/ast/declaration.h"
|
|
#include "executable_semantics/ast/expression.h"
|
|
#include "executable_semantics/common/arena.h"
|
|
#include "executable_semantics/common/error.h"
|
|
#include "executable_semantics/interpreter/action.h"
|
|
#include "executable_semantics/interpreter/stack.h"
|
|
#include "llvm/ADT/StringExtras.h"
|
|
#include "llvm/Support/Casting.h"
|
|
|
|
using llvm::cast;
|
|
using llvm::dyn_cast;
|
|
|
|
namespace Carbon {
|
|
|
|
//
|
|
// Auxiliary Functions
|
|
//
|
|
|
|
void Interpreter::PrintEnv(Env values, llvm::raw_ostream& out) {
|
|
llvm::ListSeparator sep;
|
|
for (const auto& [name, allocation] : values) {
|
|
out << sep << name << ": ";
|
|
heap_.PrintAllocation(allocation, out);
|
|
}
|
|
}
|
|
|
|
//
|
|
// State Operations
|
|
//
|
|
|
|
auto Interpreter::CurrentScope() -> Scope& {
|
|
for (const std::unique_ptr<Action>& action : todo_) {
|
|
if (action->scope().has_value()) {
|
|
return *action->scope();
|
|
}
|
|
}
|
|
FATAL() << "No current scope";
|
|
}
|
|
|
|
auto Interpreter::CurrentEnv() -> Env { return CurrentScope().values(); }
|
|
|
|
// Returns the given name from the environment, printing an error if not found.
|
|
auto Interpreter::GetFromEnv(SourceLocation source_loc, const std::string& name)
|
|
-> Address {
|
|
std::optional<AllocationId> pointer = CurrentEnv().Get(name);
|
|
if (!pointer) {
|
|
FATAL_RUNTIME_ERROR(source_loc) << "could not find `" << name << "`";
|
|
}
|
|
return Address(*pointer);
|
|
}
|
|
|
|
void Interpreter::PrintState(llvm::raw_ostream& out) {
|
|
out << "{\nstack: ";
|
|
llvm::ListSeparator sep(" :: ");
|
|
for (const std::unique_ptr<Action>& action : todo_) {
|
|
out << sep << *action;
|
|
}
|
|
out << "\nheap: " << heap_;
|
|
if (!todo_.IsEmpty()) {
|
|
out << "\nvalues: ";
|
|
PrintEnv(CurrentEnv(), out);
|
|
}
|
|
out << "\n}\n";
|
|
}
|
|
|
|
auto Interpreter::EvalPrim(Operator op,
|
|
const std::vector<Nonnull<const Value*>>& args,
|
|
SourceLocation source_loc) -> Nonnull<const Value*> {
|
|
switch (op) {
|
|
case Operator::Neg:
|
|
return arena_->New<IntValue>(-cast<IntValue>(*args[0]).value());
|
|
case Operator::Add:
|
|
return arena_->New<IntValue>(cast<IntValue>(*args[0]).value() +
|
|
cast<IntValue>(*args[1]).value());
|
|
case Operator::Sub:
|
|
return arena_->New<IntValue>(cast<IntValue>(*args[0]).value() -
|
|
cast<IntValue>(*args[1]).value());
|
|
case Operator::Mul:
|
|
return arena_->New<IntValue>(cast<IntValue>(*args[0]).value() *
|
|
cast<IntValue>(*args[1]).value());
|
|
case Operator::Not:
|
|
return arena_->New<BoolValue>(!cast<BoolValue>(*args[0]).value());
|
|
case Operator::And:
|
|
return arena_->New<BoolValue>(cast<BoolValue>(*args[0]).value() &&
|
|
cast<BoolValue>(*args[1]).value());
|
|
case Operator::Or:
|
|
return arena_->New<BoolValue>(cast<BoolValue>(*args[0]).value() ||
|
|
cast<BoolValue>(*args[1]).value());
|
|
case Operator::Eq:
|
|
return arena_->New<BoolValue>(ValueEqual(args[0], args[1], source_loc));
|
|
case Operator::Ptr:
|
|
return arena_->New<PointerType>(args[0]);
|
|
case Operator::Deref:
|
|
FATAL() << "dereference not implemented yet";
|
|
}
|
|
}
|
|
|
|
void Interpreter::InitEnv(const Declaration& d, Env* env) {
|
|
switch (d.kind()) {
|
|
case DeclarationKind::FunctionDeclaration: {
|
|
const auto& func_def = cast<FunctionDeclaration>(d);
|
|
Env new_env = *env;
|
|
// Bring the deduced parameters into scope.
|
|
for (Nonnull<const GenericBinding*> deduced :
|
|
func_def.deduced_parameters()) {
|
|
AllocationId a =
|
|
heap_.AllocateValue(arena_->New<VariableType>(deduced->name()));
|
|
new_env.Set(deduced->name(), a);
|
|
}
|
|
Nonnull<const FunctionValue*> f = arena_->New<FunctionValue>(&func_def);
|
|
AllocationId a = heap_.AllocateValue(f);
|
|
env->Set(func_def.name(), a);
|
|
break;
|
|
}
|
|
|
|
case DeclarationKind::ClassDeclaration: {
|
|
const auto& class_decl = cast<ClassDeclaration>(d);
|
|
std::vector<NamedValue> fields;
|
|
std::vector<NamedValue> methods;
|
|
for (Nonnull<const Member*> m : class_decl.members()) {
|
|
switch (m->kind()) {
|
|
case MemberKind::FieldMember: {
|
|
const BindingPattern& binding = cast<FieldMember>(*m).binding();
|
|
const Expression& type_expression =
|
|
cast<ExpressionPattern>(binding.type()).expression();
|
|
auto type = InterpExp(Env(arena_), &type_expression);
|
|
fields.push_back({.name = *binding.name(), .value = type});
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
auto st = arena_->New<NominalClassType>(
|
|
class_decl.name(), std::move(fields), std::move(methods));
|
|
AllocationId a = heap_.AllocateValue(st);
|
|
env->Set(class_decl.name(), a);
|
|
break;
|
|
}
|
|
|
|
case DeclarationKind::ChoiceDeclaration: {
|
|
const auto& choice = cast<ChoiceDeclaration>(d);
|
|
std::vector<NamedValue> alts;
|
|
for (Nonnull<const AlternativeSignature*> alternative :
|
|
choice.alternatives()) {
|
|
auto t = InterpExp(Env(arena_), &alternative->signature());
|
|
alts.push_back({.name = alternative->name(), .value = t});
|
|
}
|
|
auto ct = arena_->New<ChoiceType>(choice.name(), std::move(alts));
|
|
AllocationId a = heap_.AllocateValue(ct);
|
|
env->Set(choice.name(), a);
|
|
break;
|
|
}
|
|
|
|
case DeclarationKind::VariableDeclaration: {
|
|
const auto& var = cast<VariableDeclaration>(d);
|
|
// Adds an entry in `globals` mapping the variable's name to the
|
|
// result of evaluating the initializer.
|
|
Nonnull<const Value*> v =
|
|
Convert(InterpExp(*env, &var.initializer()), &var.static_type());
|
|
AllocationId a = heap_.AllocateValue(v);
|
|
env->Set(*var.binding().name(), a);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
void Interpreter::InitGlobals(llvm::ArrayRef<Nonnull<Declaration*>> fs) {
|
|
for (const auto d : fs) {
|
|
InitEnv(*d, &globals_);
|
|
}
|
|
}
|
|
|
|
auto Interpreter::CreateStruct(const std::vector<FieldInitializer>& fields,
|
|
const std::vector<Nonnull<const Value*>>& values)
|
|
-> Nonnull<const Value*> {
|
|
CHECK(fields.size() == values.size());
|
|
std::vector<NamedValue> elements;
|
|
for (size_t i = 0; i < fields.size(); ++i) {
|
|
elements.push_back({.name = fields[i].name(), .value = values[i]});
|
|
}
|
|
|
|
return arena_->New<StructValue>(std::move(elements));
|
|
}
|
|
|
|
auto Interpreter::PatternMatch(Nonnull<const Value*> p, Nonnull<const Value*> v,
|
|
SourceLocation source_loc)
|
|
-> std::optional<Env> {
|
|
switch (p->kind()) {
|
|
case Value::Kind::BindingPlaceholderValue: {
|
|
const auto& placeholder = cast<BindingPlaceholderValue>(*p);
|
|
Env values(arena_);
|
|
if (placeholder.name().has_value()) {
|
|
AllocationId a = heap_.AllocateValue(v);
|
|
values.Set(*placeholder.name(), a);
|
|
}
|
|
return values;
|
|
}
|
|
case Value::Kind::TupleValue:
|
|
switch (v->kind()) {
|
|
case Value::Kind::TupleValue: {
|
|
const auto& p_tup = cast<TupleValue>(*p);
|
|
const auto& v_tup = cast<TupleValue>(*v);
|
|
if (p_tup.elements().size() != v_tup.elements().size()) {
|
|
FATAL_PROGRAM_ERROR(source_loc)
|
|
<< "arity mismatch in tuple pattern match:\n pattern: "
|
|
<< p_tup << "\n value: " << v_tup;
|
|
}
|
|
Env values(arena_);
|
|
for (size_t i = 0; i < p_tup.elements().size(); ++i) {
|
|
std::optional<Env> matches = PatternMatch(
|
|
p_tup.elements()[i], v_tup.elements()[i], source_loc);
|
|
if (!matches) {
|
|
return std::nullopt;
|
|
}
|
|
for (const auto& [name, value] : *matches) {
|
|
values.Set(name, value);
|
|
}
|
|
} // for
|
|
return values;
|
|
}
|
|
default:
|
|
FATAL() << "expected a tuple value in pattern, not " << *v;
|
|
}
|
|
case Value::Kind::StructValue: {
|
|
const auto& p_struct = cast<StructValue>(*p);
|
|
const auto& v_struct = cast<StructValue>(*v);
|
|
CHECK(p_struct.elements().size() == v_struct.elements().size());
|
|
Env values(arena_);
|
|
for (size_t i = 0; i < p_struct.elements().size(); ++i) {
|
|
CHECK(p_struct.elements()[i].name == v_struct.elements()[i].name);
|
|
std::optional<Env> matches =
|
|
PatternMatch(p_struct.elements()[i].value,
|
|
v_struct.elements()[i].value, source_loc);
|
|
if (!matches) {
|
|
return std::nullopt;
|
|
}
|
|
for (const auto& [name, value] : *matches) {
|
|
values.Set(name, value);
|
|
}
|
|
}
|
|
return values;
|
|
}
|
|
case Value::Kind::AlternativeValue:
|
|
switch (v->kind()) {
|
|
case Value::Kind::AlternativeValue: {
|
|
const auto& p_alt = cast<AlternativeValue>(*p);
|
|
const auto& v_alt = cast<AlternativeValue>(*v);
|
|
if (p_alt.choice_name() != v_alt.choice_name() ||
|
|
p_alt.alt_name() != v_alt.alt_name()) {
|
|
return std::nullopt;
|
|
}
|
|
return PatternMatch(&p_alt.argument(), &v_alt.argument(), source_loc);
|
|
}
|
|
default:
|
|
FATAL() << "expected a choice alternative in pattern, not " << *v;
|
|
}
|
|
case Value::Kind::FunctionType:
|
|
switch (v->kind()) {
|
|
case Value::Kind::FunctionType: {
|
|
const auto& p_fn = cast<FunctionType>(*p);
|
|
const auto& v_fn = cast<FunctionType>(*v);
|
|
std::optional<Env> param_matches =
|
|
PatternMatch(&p_fn.parameters(), &v_fn.parameters(), source_loc);
|
|
if (!param_matches) {
|
|
return std::nullopt;
|
|
}
|
|
std::optional<Env> ret_matches = PatternMatch(
|
|
&p_fn.return_type(), &v_fn.return_type(), source_loc);
|
|
if (!ret_matches) {
|
|
return std::nullopt;
|
|
}
|
|
Env values = *param_matches;
|
|
for (const auto& [name, value] : *ret_matches) {
|
|
values.Set(name, value);
|
|
}
|
|
return values;
|
|
}
|
|
default:
|
|
return std::nullopt;
|
|
}
|
|
case Value::Kind::AutoType:
|
|
// `auto` matches any type, without binding any new names. We rely
|
|
// on the typechecker to ensure that `v` is a type.
|
|
return Env(arena_);
|
|
default:
|
|
if (ValueEqual(p, v, source_loc)) {
|
|
return Env(arena_);
|
|
} else {
|
|
return std::nullopt;
|
|
}
|
|
}
|
|
}
|
|
|
|
void Interpreter::PatternAssignment(Nonnull<const Value*> pat,
|
|
Nonnull<const Value*> val,
|
|
SourceLocation source_loc) {
|
|
switch (pat->kind()) {
|
|
case Value::Kind::PointerValue:
|
|
heap_.Write(cast<PointerValue>(*pat).value(), val, source_loc);
|
|
break;
|
|
case Value::Kind::TupleValue: {
|
|
switch (val->kind()) {
|
|
case Value::Kind::TupleValue: {
|
|
const auto& pat_tup = cast<TupleValue>(*pat);
|
|
const auto& val_tup = cast<TupleValue>(*val);
|
|
if (pat_tup.elements().size() != val_tup.elements().size()) {
|
|
FATAL_RUNTIME_ERROR(source_loc)
|
|
<< "arity mismatch in tuple pattern assignment:\n pattern: "
|
|
<< pat_tup << "\n value: " << val_tup;
|
|
}
|
|
for (size_t i = 0; i < pat_tup.elements().size(); ++i) {
|
|
PatternAssignment(pat_tup.elements()[i], val_tup.elements()[i],
|
|
source_loc);
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
FATAL() << "expected a tuple value on right-hand-side, not " << *val;
|
|
}
|
|
break;
|
|
}
|
|
case Value::Kind::AlternativeValue: {
|
|
switch (val->kind()) {
|
|
case Value::Kind::AlternativeValue: {
|
|
const auto& pat_alt = cast<AlternativeValue>(*pat);
|
|
const auto& val_alt = cast<AlternativeValue>(*val);
|
|
CHECK(val_alt.choice_name() == pat_alt.choice_name() &&
|
|
val_alt.alt_name() == pat_alt.alt_name())
|
|
<< "internal error in pattern assignment";
|
|
PatternAssignment(&pat_alt.argument(), &val_alt.argument(),
|
|
source_loc);
|
|
break;
|
|
}
|
|
default:
|
|
FATAL() << "expected an alternative in left-hand-side, not " << *val;
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
CHECK(ValueEqual(pat, val, source_loc))
|
|
<< "internal error in pattern assignment";
|
|
}
|
|
}
|
|
|
|
auto Interpreter::StepLvalue() -> Transition {
|
|
Action& act = *todo_.Top();
|
|
const Expression& exp = cast<LValAction>(act).expression();
|
|
if (trace_) {
|
|
llvm::outs() << "--- step lvalue " << exp << " (" << exp.source_loc()
|
|
<< ") --->\n";
|
|
}
|
|
switch (exp.kind()) {
|
|
case ExpressionKind::IdentifierExpression: {
|
|
// { {x :: C, E, F} :: S, H}
|
|
// -> { {E(x) :: C, E, F} :: S, H}
|
|
Address pointer =
|
|
GetFromEnv(exp.source_loc(), cast<IdentifierExpression>(exp).name());
|
|
Nonnull<const Value*> v = arena_->New<PointerValue>(pointer);
|
|
return Done{v};
|
|
}
|
|
case ExpressionKind::FieldAccessExpression: {
|
|
if (act.pos() == 0) {
|
|
// { {e.f :: C, E, F} :: S, H}
|
|
// -> { e :: [].f :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<LValAction>(
|
|
&cast<FieldAccessExpression>(exp).aggregate())};
|
|
} else {
|
|
// { v :: [].f :: C, E, F} :: S, H}
|
|
// -> { { &v.f :: C, E, F} :: S, H }
|
|
Address aggregate = cast<PointerValue>(*act.results()[0]).value();
|
|
Address field = aggregate.SubobjectAddress(
|
|
cast<FieldAccessExpression>(exp).field());
|
|
return Done{arena_->New<PointerValue>(field)};
|
|
}
|
|
}
|
|
case ExpressionKind::IndexExpression: {
|
|
if (act.pos() == 0) {
|
|
// { {e[i] :: C, E, F} :: S, H}
|
|
// -> { e :: [][i] :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<LValAction>(
|
|
&cast<IndexExpression>(exp).aggregate())};
|
|
|
|
} else if (act.pos() == 1) {
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
&cast<IndexExpression>(exp).offset())};
|
|
} else {
|
|
// { v :: [][i] :: C, E, F} :: S, H}
|
|
// -> { { &v[i] :: C, E, F} :: S, H }
|
|
Address aggregate = cast<PointerValue>(*act.results()[0]).value();
|
|
std::string f =
|
|
std::to_string(cast<IntValue>(*act.results()[1]).value());
|
|
Address field = aggregate.SubobjectAddress(f);
|
|
return Done{arena_->New<PointerValue>(field)};
|
|
}
|
|
}
|
|
case ExpressionKind::TupleLiteral: {
|
|
if (act.pos() <
|
|
static_cast<int>(cast<TupleLiteral>(exp).fields().size())) {
|
|
// { { vk :: (f1=v1,..., fk=[],fk+1=ek+1,...) :: C, E, F} :: S,
|
|
// H}
|
|
// -> { { ek+1 :: (f1=v1,..., fk=vk, fk+1=[],...) :: C, E, F} :: S,
|
|
// H}
|
|
return Spawn{std::make_unique<LValAction>(
|
|
cast<TupleLiteral>(exp).fields()[act.pos()])};
|
|
} else {
|
|
return Done{arena_->New<TupleValue>(act.results())};
|
|
}
|
|
}
|
|
case ExpressionKind::StructLiteral:
|
|
case ExpressionKind::StructTypeLiteral:
|
|
case ExpressionKind::IntLiteral:
|
|
case ExpressionKind::BoolLiteral:
|
|
case ExpressionKind::CallExpression:
|
|
case ExpressionKind::PrimitiveOperatorExpression:
|
|
case ExpressionKind::IntTypeLiteral:
|
|
case ExpressionKind::BoolTypeLiteral:
|
|
case ExpressionKind::TypeTypeLiteral:
|
|
case ExpressionKind::FunctionTypeLiteral:
|
|
case ExpressionKind::ContinuationTypeLiteral:
|
|
case ExpressionKind::StringLiteral:
|
|
case ExpressionKind::StringTypeLiteral:
|
|
case ExpressionKind::IntrinsicExpression:
|
|
FATAL_RUNTIME_ERROR_NO_LINE()
|
|
<< "Can't treat expression as lvalue: " << exp;
|
|
}
|
|
}
|
|
|
|
auto Interpreter::Convert(Nonnull<const Value*> value,
|
|
Nonnull<const Value*> destination_type) const
|
|
-> Nonnull<const Value*> {
|
|
switch (value->kind()) {
|
|
case Value::Kind::IntValue:
|
|
case Value::Kind::FunctionValue:
|
|
case Value::Kind::PointerValue:
|
|
case Value::Kind::BoolValue:
|
|
case Value::Kind::NominalClassValue:
|
|
case Value::Kind::AlternativeValue:
|
|
case Value::Kind::IntType:
|
|
case Value::Kind::BoolType:
|
|
case Value::Kind::TypeType:
|
|
case Value::Kind::FunctionType:
|
|
case Value::Kind::PointerType:
|
|
case Value::Kind::AutoType:
|
|
case Value::Kind::StructType:
|
|
case Value::Kind::NominalClassType:
|
|
case Value::Kind::ChoiceType:
|
|
case Value::Kind::ContinuationType:
|
|
case Value::Kind::VariableType:
|
|
case Value::Kind::BindingPlaceholderValue:
|
|
case Value::Kind::AlternativeConstructorValue:
|
|
case Value::Kind::ContinuationValue:
|
|
case Value::Kind::StringType:
|
|
case Value::Kind::StringValue:
|
|
// TODO: add `CHECK(TypeEqual(type, value->dynamic_type()))`, once we
|
|
// have Value::dynamic_type.
|
|
return value;
|
|
case Value::Kind::StructValue: {
|
|
const auto& struct_val = cast<StructValue>(*value);
|
|
switch (destination_type->kind()) {
|
|
case Value::Kind::StructType: {
|
|
const auto& destination_struct_type =
|
|
cast<StructType>(*destination_type);
|
|
std::vector<NamedValue> new_elements;
|
|
for (const auto& [field_name, field_type] :
|
|
destination_struct_type.fields()) {
|
|
std::optional<Nonnull<const Value*>> old_value =
|
|
struct_val.FindField(field_name);
|
|
new_elements.push_back(
|
|
{.name = field_name, .value = Convert(*old_value, field_type)});
|
|
}
|
|
return arena_->New<StructValue>(std::move(new_elements));
|
|
}
|
|
case Value::Kind::NominalClassType:
|
|
return arena_->New<NominalClassValue>(destination_type, value);
|
|
default:
|
|
FATAL() << "Can't convert value " << *value << " to type "
|
|
<< *destination_type;
|
|
}
|
|
}
|
|
case Value::Kind::TupleValue: {
|
|
const auto& tuple = cast<TupleValue>(value);
|
|
const auto& destination_tuple_type = cast<TupleValue>(destination_type);
|
|
CHECK(tuple->elements().size() ==
|
|
destination_tuple_type->elements().size());
|
|
std::vector<Nonnull<const Value*>> new_elements;
|
|
for (size_t i = 0; i < tuple->elements().size(); ++i) {
|
|
new_elements.push_back(Convert(tuple->elements()[i],
|
|
destination_tuple_type->elements()[i]));
|
|
}
|
|
return arena_->New<TupleValue>(std::move(new_elements));
|
|
}
|
|
}
|
|
}
|
|
|
|
auto Interpreter::StepExp() -> Transition {
|
|
Action& act = *todo_.Top();
|
|
const Expression& exp = cast<ExpressionAction>(act).expression();
|
|
if (trace_) {
|
|
llvm::outs() << "--- step exp " << exp << " (" << exp.source_loc()
|
|
<< ") --->\n";
|
|
}
|
|
switch (exp.kind()) {
|
|
case ExpressionKind::IndexExpression: {
|
|
if (act.pos() == 0) {
|
|
// { { e[i] :: C, E, F} :: S, H}
|
|
// -> { { e :: [][i] :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
&cast<IndexExpression>(exp).aggregate())};
|
|
} else if (act.pos() == 1) {
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
&cast<IndexExpression>(exp).offset())};
|
|
} else {
|
|
// { { v :: [][i] :: C, E, F} :: S, H}
|
|
// -> { { v_i :: C, E, F} : S, H}
|
|
const auto& tuple = cast<TupleValue>(*act.results()[0]);
|
|
int i = cast<IntValue>(*act.results()[1]).value();
|
|
if (i < 0 || i >= static_cast<int>(tuple.elements().size())) {
|
|
FATAL_RUNTIME_ERROR_NO_LINE()
|
|
<< "index " << i << " out of range in " << tuple;
|
|
}
|
|
return Done{tuple.elements()[i]};
|
|
}
|
|
}
|
|
case ExpressionKind::TupleLiteral: {
|
|
if (act.pos() <
|
|
static_cast<int>(cast<TupleLiteral>(exp).fields().size())) {
|
|
// { { vk :: (f1=v1,..., fk=[],fk+1=ek+1,...) :: C, E, F} :: S,
|
|
// H}
|
|
// -> { { ek+1 :: (f1=v1,..., fk=vk, fk+1=[],...) :: C, E, F} :: S,
|
|
// H}
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
cast<TupleLiteral>(exp).fields()[act.pos()])};
|
|
} else {
|
|
return Done{arena_->New<TupleValue>(act.results())};
|
|
}
|
|
}
|
|
case ExpressionKind::StructLiteral: {
|
|
const auto& literal = cast<StructLiteral>(exp);
|
|
if (act.pos() < static_cast<int>(literal.fields().size())) {
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
&literal.fields()[act.pos()].expression())};
|
|
} else {
|
|
return Done{CreateStruct(literal.fields(), act.results())};
|
|
}
|
|
}
|
|
case ExpressionKind::StructTypeLiteral: {
|
|
const auto& struct_type = cast<StructTypeLiteral>(exp);
|
|
if (act.pos() < static_cast<int>(struct_type.fields().size())) {
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
&struct_type.fields()[act.pos()].expression())};
|
|
} else {
|
|
std::vector<NamedValue> fields;
|
|
for (size_t i = 0; i < struct_type.fields().size(); ++i) {
|
|
fields.push_back({struct_type.fields()[i].name(), act.results()[i]});
|
|
}
|
|
return Done{arena_->New<StructType>(std::move(fields))};
|
|
}
|
|
}
|
|
case ExpressionKind::FieldAccessExpression: {
|
|
const auto& access = cast<FieldAccessExpression>(exp);
|
|
if (act.pos() == 0) {
|
|
// { { e.f :: C, E, F} :: S, H}
|
|
// -> { { e :: [].f :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<ExpressionAction>(&access.aggregate())};
|
|
} else {
|
|
// { { v :: [].f :: C, E, F} :: S, H}
|
|
// -> { { v_f :: C, E, F} : S, H}
|
|
return Done{act.results()[0]->GetField(
|
|
arena_, FieldPath(access.field()), exp.source_loc())};
|
|
}
|
|
}
|
|
case ExpressionKind::IdentifierExpression: {
|
|
CHECK(act.pos() == 0);
|
|
const auto& ident = cast<IdentifierExpression>(exp);
|
|
// { {x :: C, E, F} :: S, H} -> { {H(E(x)) :: C, E, F} :: S, H}
|
|
Address pointer = GetFromEnv(exp.source_loc(), ident.name());
|
|
return Done{heap_.Read(pointer, exp.source_loc())};
|
|
}
|
|
case ExpressionKind::IntLiteral:
|
|
CHECK(act.pos() == 0);
|
|
// { {n :: C, E, F} :: S, H} -> { {n' :: C, E, F} :: S, H}
|
|
return Done{arena_->New<IntValue>(cast<IntLiteral>(exp).value())};
|
|
case ExpressionKind::BoolLiteral:
|
|
CHECK(act.pos() == 0);
|
|
// { {n :: C, E, F} :: S, H} -> { {n' :: C, E, F} :: S, H}
|
|
return Done{arena_->New<BoolValue>(cast<BoolLiteral>(exp).value())};
|
|
case ExpressionKind::PrimitiveOperatorExpression: {
|
|
const auto& op = cast<PrimitiveOperatorExpression>(exp);
|
|
if (act.pos() != static_cast<int>(op.arguments().size())) {
|
|
// { {v :: op(vs,[],e,es) :: C, E, F} :: S, H}
|
|
// -> { {e :: op(vs,v,[],es) :: C, E, F} :: S, H}
|
|
Nonnull<const Expression*> arg = op.arguments()[act.pos()];
|
|
return Spawn{std::make_unique<ExpressionAction>(arg)};
|
|
} else {
|
|
// { {v :: op(vs,[]) :: C, E, F} :: S, H}
|
|
// -> { {eval_prim(op, (vs,v)) :: C, E, F} :: S, H}
|
|
return Done{EvalPrim(op.op(), act.results(), exp.source_loc())};
|
|
}
|
|
}
|
|
case ExpressionKind::CallExpression:
|
|
if (act.pos() == 0) {
|
|
// { {e1(e2) :: C, E, F} :: S, H}
|
|
// -> { {e1 :: [](e2) :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
&cast<CallExpression>(exp).function())};
|
|
} else if (act.pos() == 1) {
|
|
// { { v :: [](e) :: C, E, F} :: S, H}
|
|
// -> { { e :: v([]) :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
&cast<CallExpression>(exp).argument())};
|
|
} else if (act.pos() == 2) {
|
|
// { { v2 :: v1([]) :: C, E, F} :: S, H}
|
|
// -> { {C',E',F'} :: {C, E, F} :: S, H}
|
|
switch (act.results()[0]->kind()) {
|
|
case Value::Kind::AlternativeConstructorValue: {
|
|
const auto& alt =
|
|
cast<AlternativeConstructorValue>(*act.results()[0]);
|
|
return Done{arena_->New<AlternativeValue>(
|
|
alt.alt_name(), alt.choice_name(), act.results()[1])};
|
|
}
|
|
case Value::Kind::FunctionValue:
|
|
return CallFunction{
|
|
.function =
|
|
&cast<FunctionValue>(*act.results()[0]).declaration(),
|
|
.args = act.results()[1],
|
|
.source_loc = exp.source_loc()};
|
|
default:
|
|
FATAL_RUNTIME_ERROR(exp.source_loc())
|
|
<< "in call, expected a function, not " << *act.results()[0];
|
|
}
|
|
} else if (act.pos() == 3) {
|
|
if (act.results().size() < 3) {
|
|
// Control fell through without explicit return.
|
|
return Done{TupleValue::Empty()};
|
|
} else {
|
|
return Done{act.results()[2]};
|
|
}
|
|
} else {
|
|
FATAL() << "in handle_value with Call pos " << act.pos();
|
|
}
|
|
case ExpressionKind::IntrinsicExpression:
|
|
CHECK(act.pos() == 0);
|
|
// { {n :: C, E, F} :: S, H} -> { {n' :: C, E, F} :: S, H}
|
|
switch (cast<IntrinsicExpression>(exp).intrinsic()) {
|
|
case IntrinsicExpression::Intrinsic::Print:
|
|
Address pointer = GetFromEnv(exp.source_loc(), "format_str");
|
|
Nonnull<const Value*> pointee = heap_.Read(pointer, exp.source_loc());
|
|
CHECK(pointee->kind() == Value::Kind::StringValue);
|
|
// TODO: This could eventually use something like llvm::formatv.
|
|
llvm::outs() << cast<StringValue>(*pointee).value();
|
|
return Done{TupleValue::Empty()};
|
|
}
|
|
|
|
case ExpressionKind::IntTypeLiteral: {
|
|
CHECK(act.pos() == 0);
|
|
return Done{arena_->New<IntType>()};
|
|
}
|
|
case ExpressionKind::BoolTypeLiteral: {
|
|
CHECK(act.pos() == 0);
|
|
return Done{arena_->New<BoolType>()};
|
|
}
|
|
case ExpressionKind::TypeTypeLiteral: {
|
|
CHECK(act.pos() == 0);
|
|
return Done{arena_->New<TypeType>()};
|
|
}
|
|
case ExpressionKind::FunctionTypeLiteral: {
|
|
if (act.pos() == 0) {
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
&cast<FunctionTypeLiteral>(exp).parameter())};
|
|
} else if (act.pos() == 1) {
|
|
// { { pt :: fn [] -> e :: C, E, F} :: S, H}
|
|
// -> { { e :: fn pt -> []) :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
&cast<FunctionTypeLiteral>(exp).return_type())};
|
|
} else {
|
|
// { { rt :: fn pt -> [] :: C, E, F} :: S, H}
|
|
// -> { fn pt -> rt :: {C, E, F} :: S, H}
|
|
return Done{arena_->New<FunctionType>(
|
|
std::vector<Nonnull<const GenericBinding*>>(), act.results()[0],
|
|
act.results()[1])};
|
|
}
|
|
}
|
|
case ExpressionKind::ContinuationTypeLiteral: {
|
|
CHECK(act.pos() == 0);
|
|
return Done{arena_->New<ContinuationType>()};
|
|
}
|
|
case ExpressionKind::StringLiteral:
|
|
CHECK(act.pos() == 0);
|
|
// { {n :: C, E, F} :: S, H} -> { {n' :: C, E, F} :: S, H}
|
|
return Done{arena_->New<StringValue>(cast<StringLiteral>(exp).value())};
|
|
case ExpressionKind::StringTypeLiteral: {
|
|
CHECK(act.pos() == 0);
|
|
return Done{arena_->New<StringType>()};
|
|
}
|
|
} // switch (exp->kind)
|
|
}
|
|
|
|
auto Interpreter::StepPattern() -> Transition {
|
|
Action& act = *todo_.Top();
|
|
const Pattern& pattern = cast<PatternAction>(act).pattern();
|
|
if (trace_) {
|
|
llvm::outs() << "--- step pattern " << pattern << " ("
|
|
<< pattern.source_loc() << ") --->\n";
|
|
}
|
|
switch (pattern.kind()) {
|
|
case PatternKind::AutoPattern: {
|
|
CHECK(act.pos() == 0);
|
|
return Done{arena_->New<AutoType>()};
|
|
}
|
|
case PatternKind::BindingPattern: {
|
|
const auto& binding = cast<BindingPattern>(pattern);
|
|
if (act.pos() == 0) {
|
|
return Spawn{std::make_unique<PatternAction>(&binding.type())};
|
|
} else {
|
|
return Done{arena_->New<BindingPlaceholderValue>(binding.name(),
|
|
act.results()[0])};
|
|
}
|
|
}
|
|
case PatternKind::TuplePattern: {
|
|
const auto& tuple = cast<TuplePattern>(pattern);
|
|
if (act.pos() < static_cast<int>(tuple.fields().size())) {
|
|
// { { vk :: (f1=v1,..., fk=[],fk+1=ek+1,...) :: C, E, F} :: S,
|
|
// H}
|
|
// -> { { ek+1 :: (f1=v1,..., fk=vk, fk+1=[],...) :: C, E, F} :: S,
|
|
// H}
|
|
return Spawn{
|
|
std::make_unique<PatternAction>(tuple.fields()[act.pos()])};
|
|
} else {
|
|
return Done{arena_->New<TupleValue>(act.results())};
|
|
}
|
|
}
|
|
case PatternKind::AlternativePattern: {
|
|
const auto& alternative = cast<AlternativePattern>(pattern);
|
|
if (act.pos() == 0) {
|
|
return Spawn{
|
|
std::make_unique<ExpressionAction>(&alternative.choice_type())};
|
|
} else if (act.pos() == 1) {
|
|
return Spawn{std::make_unique<PatternAction>(&alternative.arguments())};
|
|
} else {
|
|
CHECK(act.pos() == 2);
|
|
const auto& choice_type = cast<ChoiceType>(*act.results()[0]);
|
|
return Done{arena_->New<AlternativeValue>(
|
|
alternative.alternative_name(), choice_type.name(),
|
|
act.results()[1])};
|
|
}
|
|
}
|
|
case PatternKind::ExpressionPattern:
|
|
return Delegate{std::make_unique<ExpressionAction>(
|
|
&cast<ExpressionPattern>(pattern).expression())};
|
|
}
|
|
}
|
|
|
|
static auto IsRunAction(const Action& action) -> bool {
|
|
const auto* statement = dyn_cast<StatementAction>(&action);
|
|
return statement != nullptr && llvm::isa<Run>(statement->statement());
|
|
}
|
|
|
|
auto Interpreter::StepStmt() -> Transition {
|
|
Action& act = *todo_.Top();
|
|
const Statement& stmt = cast<StatementAction>(act).statement();
|
|
if (trace_) {
|
|
llvm::outs() << "--- step stmt ";
|
|
stmt.PrintDepth(1, llvm::outs());
|
|
llvm::outs() << " (" << stmt.source_loc() << ") --->\n";
|
|
}
|
|
switch (stmt.kind()) {
|
|
case StatementKind::Match: {
|
|
const auto& match_stmt = cast<Match>(stmt);
|
|
if (act.pos() == 0) {
|
|
// { { (match (e) ...) :: C, E, F} :: S, H}
|
|
// -> { { e :: (match ([]) ...) :: C, E, F} :: S, H}
|
|
act.StartScope(Scope(CurrentEnv(), &heap_));
|
|
return Spawn{
|
|
std::make_unique<ExpressionAction>(&match_stmt.expression())};
|
|
} else {
|
|
int clause_num = act.pos() - 1;
|
|
if (clause_num >= static_cast<int>(match_stmt.clauses().size())) {
|
|
return Done{};
|
|
}
|
|
auto c = match_stmt.clauses()[clause_num];
|
|
std::optional<Env> matches =
|
|
PatternMatch(&c.pattern().value(),
|
|
Convert(act.results()[0], &c.pattern().static_type()),
|
|
stmt.source_loc());
|
|
if (matches) { // We have a match, start the body.
|
|
// Ensure we don't process any more clauses.
|
|
act.set_pos(match_stmt.clauses().size() + 1);
|
|
|
|
for (const auto& [name, value] : *matches) {
|
|
act.scope()->AddLocal(name, value);
|
|
}
|
|
return Spawn{std::make_unique<StatementAction>(&c.statement())};
|
|
} else {
|
|
return RunAgain{};
|
|
}
|
|
}
|
|
}
|
|
case StatementKind::While:
|
|
if (act.pos() % 2 == 0) {
|
|
// { { (while (e) s) :: C, E, F} :: S, H}
|
|
// -> { { e :: (while ([]) s) :: C, E, F} :: S, H}
|
|
act.Clear();
|
|
return Spawn{
|
|
std::make_unique<ExpressionAction>(&cast<While>(stmt).condition())};
|
|
} else {
|
|
Nonnull<const Value*> condition =
|
|
Convert(act.results().back(), arena_->New<BoolType>());
|
|
if (cast<BoolValue>(*condition).value()) {
|
|
// { {true :: (while ([]) s) :: C, E, F} :: S, H}
|
|
// -> { { s :: (while (e) s) :: C, E, F } :: S, H}
|
|
return Spawn{
|
|
std::make_unique<StatementAction>(&cast<While>(stmt).body())};
|
|
} else {
|
|
// { {false :: (while ([]) s) :: C, E, F} :: S, H}
|
|
// -> { { C, E, F } :: S, H}
|
|
return Done{};
|
|
}
|
|
}
|
|
case StatementKind::Break: {
|
|
CHECK(act.pos() == 0);
|
|
// { { break; :: ... :: (while (e) s) :: C, E, F} :: S, H}
|
|
// -> { { C, E', F} :: S, H}
|
|
return UnwindPast{.ast_node = &cast<Break>(stmt).loop()};
|
|
}
|
|
case StatementKind::Continue: {
|
|
CHECK(act.pos() == 0);
|
|
// { { continue; :: ... :: (while (e) s) :: C, E, F} :: S, H}
|
|
// -> { { (while (e) s) :: C, E', F} :: S, H}
|
|
return UnwindTo{.ast_node = &cast<Continue>(stmt).loop()};
|
|
}
|
|
case StatementKind::Block: {
|
|
const auto& block = cast<Block>(stmt);
|
|
if (act.pos() >= static_cast<int>(block.statements().size())) {
|
|
// If the position is past the end of the block, end processing. Note
|
|
// that empty blocks immediately end.
|
|
return Done{};
|
|
}
|
|
// Initialize a scope when starting a block.
|
|
if (act.pos() == 0) {
|
|
act.StartScope(Scope(CurrentEnv(), &heap_));
|
|
}
|
|
// Process the next statement in the block. The position will be
|
|
// incremented as part of Spawn.
|
|
return Spawn{
|
|
std::make_unique<StatementAction>(block.statements()[act.pos()])};
|
|
}
|
|
case StatementKind::VariableDefinition: {
|
|
const auto& definition = cast<VariableDefinition>(stmt);
|
|
if (act.pos() == 0) {
|
|
// { {(var x = e) :: C, E, F} :: S, H}
|
|
// -> { {e :: (var x = []) :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<ExpressionAction>(&definition.init())};
|
|
} else {
|
|
// { { v :: (x = []) :: C, E, F} :: S, H}
|
|
// -> { { C, E(x := a), F} :: S, H(a := copy(v))}
|
|
Nonnull<const Value*> v =
|
|
Convert(act.results()[0], &definition.pattern().static_type());
|
|
Nonnull<const Value*> p =
|
|
&cast<VariableDefinition>(stmt).pattern().value();
|
|
|
|
std::optional<Env> matches = PatternMatch(p, v, stmt.source_loc());
|
|
CHECK(matches)
|
|
<< stmt.source_loc()
|
|
<< ": internal error in variable definition, match failed";
|
|
for (const auto& [name, value] : *matches) {
|
|
Scope& current_scope = CurrentScope();
|
|
current_scope.AddLocal(name, value);
|
|
}
|
|
return Done{};
|
|
}
|
|
}
|
|
case StatementKind::ExpressionStatement:
|
|
if (act.pos() == 0) {
|
|
// { {e :: C, E, F} :: S, H}
|
|
// -> { {e :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
&cast<ExpressionStatement>(stmt).expression())};
|
|
} else {
|
|
return Done{};
|
|
}
|
|
case StatementKind::Assign: {
|
|
const auto& assign = cast<Assign>(stmt);
|
|
if (act.pos() == 0) {
|
|
// { {(lv = e) :: C, E, F} :: S, H}
|
|
// -> { {lv :: ([] = e) :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<LValAction>(&assign.lhs())};
|
|
} else if (act.pos() == 1) {
|
|
// { { a :: ([] = e) :: C, E, F} :: S, H}
|
|
// -> { { e :: (a = []) :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<ExpressionAction>(&assign.rhs())};
|
|
} else {
|
|
// { { v :: (a = []) :: C, E, F} :: S, H}
|
|
// -> { { C, E, F} :: S, H(a := v)}
|
|
auto pat = act.results()[0];
|
|
auto val = Convert(act.results()[1], &assign.lhs().static_type());
|
|
PatternAssignment(pat, val, stmt.source_loc());
|
|
return Done{};
|
|
}
|
|
}
|
|
case StatementKind::If:
|
|
if (act.pos() == 0) {
|
|
// { {(if (e) then_stmt else else_stmt) :: C, E, F} :: S, H}
|
|
// -> { { e :: (if ([]) then_stmt else else_stmt) :: C, E, F} :: S, H}
|
|
return Spawn{
|
|
std::make_unique<ExpressionAction>(&cast<If>(stmt).condition())};
|
|
} else {
|
|
Nonnull<const Value*> condition =
|
|
Convert(act.results()[0], arena_->New<BoolType>());
|
|
if (cast<BoolValue>(*condition).value()) {
|
|
// { {true :: if ([]) then_stmt else else_stmt :: C, E, F} ::
|
|
// S, H}
|
|
// -> { { then_stmt :: C, E, F } :: S, H}
|
|
return Delegate{
|
|
std::make_unique<StatementAction>(&cast<If>(stmt).then_block())};
|
|
} else if (cast<If>(stmt).else_block()) {
|
|
// { {false :: if ([]) then_stmt else else_stmt :: C, E, F} ::
|
|
// S, H}
|
|
// -> { { else_stmt :: C, E, F } :: S, H}
|
|
return Delegate{
|
|
std::make_unique<StatementAction>(*cast<If>(stmt).else_block())};
|
|
} else {
|
|
return Done{};
|
|
}
|
|
}
|
|
case StatementKind::Return:
|
|
if (act.pos() == 0) {
|
|
// { {return e :: C, E, F} :: S, H}
|
|
// -> { {e :: return [] :: C, E, F} :: S, H}
|
|
return Spawn{std::make_unique<ExpressionAction>(
|
|
&cast<Return>(stmt).expression())};
|
|
} else {
|
|
// { {v :: return [] :: C, E, F} :: {C', E', F'} :: S, H}
|
|
// -> { {v :: C', E', F'} :: S, H}
|
|
const FunctionDeclaration& function = cast<Return>(stmt).function();
|
|
return UnwindPast{
|
|
.ast_node = *function.body(),
|
|
.result = Convert(act.results()[0],
|
|
&function.return_term().static_type())};
|
|
}
|
|
case StatementKind::Continuation: {
|
|
CHECK(act.pos() == 0);
|
|
// Create a continuation object by creating a frame similar the
|
|
// way one is created in a function call.
|
|
auto fragment = arena_->New<ContinuationValue::StackFragment>();
|
|
stack_fragments_.push_back(fragment);
|
|
std::vector<std::unique_ptr<Action>> reversed_todo;
|
|
reversed_todo.push_back(
|
|
std::make_unique<StatementAction>(&cast<Continuation>(stmt).body()));
|
|
reversed_todo.push_back(
|
|
std::make_unique<ScopeAction>(Scope(CurrentEnv(), &heap_)));
|
|
fragment->StoreReversed(std::move(reversed_todo));
|
|
AllocationId continuation_address =
|
|
heap_.AllocateValue(arena_->New<ContinuationValue>(fragment));
|
|
// Bind the continuation object to the continuation variable
|
|
CurrentScope().AddLocal(cast<Continuation>(stmt).continuation_variable(),
|
|
continuation_address);
|
|
return Done{};
|
|
}
|
|
case StatementKind::Run: {
|
|
auto& run = cast<Run>(stmt);
|
|
if (act.pos() == 0) {
|
|
// Evaluate the argument of the run statement.
|
|
return Spawn{std::make_unique<ExpressionAction>(&run.argument())};
|
|
} else if (act.pos() == 1) {
|
|
// Push the continuation onto the current stack.
|
|
cast<const ContinuationValue>(*act.results()[0])
|
|
.stack()
|
|
.RestoreTo(todo_);
|
|
act.set_pos(2);
|
|
return ManualTransition{};
|
|
} else {
|
|
return Done{};
|
|
}
|
|
}
|
|
case StatementKind::Await:
|
|
CHECK(act.pos() == 0);
|
|
// Pause the current continuation
|
|
todo_.Pop();
|
|
std::vector<std::unique_ptr<Action>> paused;
|
|
while (!IsRunAction(*todo_.Top())) {
|
|
paused.push_back(todo_.Pop());
|
|
}
|
|
const auto& continuation =
|
|
cast<const ContinuationValue>(*todo_.Top()->results()[0]);
|
|
// Update the continuation with the paused stack.
|
|
continuation.stack().StoreReversed(std::move(paused));
|
|
return ManualTransition{};
|
|
}
|
|
}
|
|
|
|
class Interpreter::DoTransition {
|
|
public:
|
|
// Does not take ownership of interpreter.
|
|
explicit DoTransition(Interpreter* interpreter) : interpreter(interpreter) {}
|
|
|
|
void operator()(const Done& done) {
|
|
std::unique_ptr<Action> act = interpreter->todo_.Pop();
|
|
switch (act->kind()) {
|
|
case Action::Kind::ExpressionAction:
|
|
case Action::Kind::LValAction:
|
|
case Action::Kind::PatternAction:
|
|
CHECK(done.result.has_value());
|
|
interpreter->todo_.Top()->AddResult(*done.result);
|
|
break;
|
|
case Action::Kind::StatementAction:
|
|
CHECK(!done.result.has_value());
|
|
break;
|
|
case Action::Kind::ScopeAction:
|
|
if (done.result.has_value()) {
|
|
interpreter->todo_.Top()->AddResult(*done.result);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
void operator()(Spawn spawn) {
|
|
Action& action = *interpreter->todo_.Top();
|
|
action.set_pos(action.pos() + 1);
|
|
interpreter->todo_.Push(std::move(spawn.child));
|
|
}
|
|
|
|
void operator()(Delegate delegate) {
|
|
std::unique_ptr<Action> act = interpreter->todo_.Pop();
|
|
if (act->scope().has_value()) {
|
|
delegate.delegate->StartScope(std::move(*act->scope()));
|
|
}
|
|
interpreter->todo_.Push(std::move(delegate.delegate));
|
|
}
|
|
|
|
void operator()(const RunAgain&) {
|
|
Action& action = *interpreter->todo_.Top();
|
|
action.set_pos(action.pos() + 1);
|
|
}
|
|
|
|
void operator()(const UnwindTo& unwind_to) { DoUnwindTo(unwind_to.ast_node); }
|
|
|
|
void operator()(const UnwindPast& unwind_past) {
|
|
DoUnwindTo(unwind_past.ast_node);
|
|
// Unwind past the statement and return a result if needed.
|
|
interpreter->todo_.Pop();
|
|
if (unwind_past.result.has_value()) {
|
|
interpreter->todo_.Top()->AddResult(*unwind_past.result);
|
|
}
|
|
}
|
|
|
|
void operator()(const CallFunction& call) {
|
|
Action& action = *interpreter->todo_.Top();
|
|
action.set_pos(action.pos() + 1);
|
|
Nonnull<const Value*> converted_args = interpreter->Convert(
|
|
call.args, &call.function->param_pattern().static_type());
|
|
std::optional<Env> matches =
|
|
interpreter->PatternMatch(&call.function->param_pattern().value(),
|
|
converted_args, call.source_loc);
|
|
CHECK(matches.has_value())
|
|
<< "internal error in call_function, pattern match failed";
|
|
// Create the new frame and push it on the stack
|
|
Scope new_scope(interpreter->globals_, &interpreter->heap_);
|
|
for (const auto& [name, value] : *matches) {
|
|
new_scope.AddLocal(name, value);
|
|
}
|
|
interpreter->todo_.Push(
|
|
std::make_unique<ScopeAction>(std::move(new_scope)));
|
|
CHECK(call.function->body()) << "Calling a function that's missing a body";
|
|
interpreter->todo_.Push(
|
|
std::make_unique<StatementAction>(*call.function->body()));
|
|
}
|
|
|
|
void operator()(const ManualTransition&) {}
|
|
|
|
private:
|
|
// Unwinds to the indicated node.
|
|
void DoUnwindTo(Nonnull<const Statement*> ast_node) {
|
|
while (true) {
|
|
if (const auto* statement_action =
|
|
dyn_cast<StatementAction>(interpreter->todo_.Top().get());
|
|
statement_action != nullptr &&
|
|
&statement_action->statement() == ast_node) {
|
|
break;
|
|
}
|
|
interpreter->todo_.Pop();
|
|
}
|
|
}
|
|
|
|
Nonnull<Interpreter*> interpreter;
|
|
};
|
|
|
|
// State transition.
|
|
void Interpreter::Step() {
|
|
Action& act = *todo_.Top();
|
|
switch (act.kind()) {
|
|
case Action::Kind::LValAction:
|
|
std::visit(DoTransition(this), StepLvalue());
|
|
break;
|
|
case Action::Kind::ExpressionAction:
|
|
std::visit(DoTransition(this), StepExp());
|
|
break;
|
|
case Action::Kind::PatternAction:
|
|
std::visit(DoTransition(this), StepPattern());
|
|
break;
|
|
case Action::Kind::StatementAction:
|
|
std::visit(DoTransition(this), StepStmt());
|
|
break;
|
|
case Action::Kind::ScopeAction:
|
|
if (act.results().empty()) {
|
|
std::visit(DoTransition(this), Transition{Done{}});
|
|
} else {
|
|
CHECK(act.results().size() == 1);
|
|
std::visit(DoTransition(this), Transition{Done{act.results()[0]}});
|
|
}
|
|
} // switch
|
|
}
|
|
|
|
auto Interpreter::ExecuteAction(std::unique_ptr<Action> action, Env values,
|
|
bool trace_steps) -> Nonnull<const Value*> {
|
|
todo_ = {};
|
|
todo_.Push(std::make_unique<ScopeAction>(Scope(values, &heap_)));
|
|
todo_.Push(std::move(action));
|
|
|
|
while (todo_.Count() > 1) {
|
|
Step();
|
|
if (trace_steps) {
|
|
PrintState(llvm::outs());
|
|
}
|
|
}
|
|
|
|
// Clean up any remaining suspended continuations.
|
|
for (Nonnull<ContinuationValue::StackFragment*> fragment : stack_fragments_) {
|
|
fragment->Clear();
|
|
}
|
|
|
|
CHECK(todo_.Top()->results().size() == 1);
|
|
return todo_.Top()->results()[0];
|
|
}
|
|
|
|
auto Interpreter::InterpProgram(llvm::ArrayRef<Nonnull<Declaration*>> fs,
|
|
Nonnull<const Expression*> call_main) -> int {
|
|
// Check that the interpreter is in a clean state.
|
|
CHECK(globals_.IsEmpty());
|
|
CHECK(todo_.IsEmpty());
|
|
|
|
if (trace_) {
|
|
llvm::outs() << "********** initializing globals **********\n";
|
|
}
|
|
InitGlobals(fs);
|
|
|
|
if (trace_) {
|
|
llvm::outs() << "********** calling main function **********\n";
|
|
PrintState(llvm::outs());
|
|
}
|
|
|
|
return cast<IntValue>(
|
|
*ExecuteAction(std::make_unique<ExpressionAction>(call_main),
|
|
globals_, trace_))
|
|
.value();
|
|
}
|
|
|
|
auto Interpreter::InterpExp(Env values, Nonnull<const Expression*> e)
|
|
-> Nonnull<const Value*> {
|
|
return ExecuteAction(std::make_unique<ExpressionAction>(e), values,
|
|
/*trace_steps=*/false);
|
|
}
|
|
|
|
auto Interpreter::InterpPattern(Env values, Nonnull<const Pattern*> p)
|
|
-> Nonnull<const Value*> {
|
|
return ExecuteAction(std::make_unique<PatternAction>(p), values,
|
|
/*trace_steps=*/false);
|
|
}
|
|
|
|
} // namespace Carbon
|