Files
carbon-lang/executable_semantics/interpreter/value.cpp
T
Geoff Romer c3c89a77a4 Delete functions that are redundant with Get methods (#664)
This change assumes that the Carbon typechecker will ensure that the corresponding Get calls are safe.
2021-07-19 09:47:26 -07:00

550 lines
16 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/value.h"
#include <algorithm>
#include <iostream>
#include "common/check.h"
#include "executable_semantics/interpreter/interpreter.h"
namespace Carbon {
auto Value::GetIntValue() const -> int {
return std::get<IntValue>(value).value;
}
auto Value::GetBoolValue() const -> bool {
return std::get<BoolValue>(value).value;
}
auto Value::GetFunctionValue() const -> const FunctionValue& {
return std::get<FunctionValue>(value);
}
auto Value::GetStructValue() const -> const StructValue& {
return std::get<StructValue>(value);
}
auto Value::GetAlternativeConstructorValue() const
-> const AlternativeConstructorValue& {
return std::get<AlternativeConstructorValue>(value);
}
auto Value::GetAlternativeValue() const -> const AlternativeValue& {
return std::get<AlternativeValue>(value);
}
auto Value::GetTupleValue() const -> const TupleValue& {
return std::get<TupleValue>(value);
}
auto Value::GetPointerValue() const -> Address {
return std::get<PointerValue>(value).value;
}
auto Value::GetBindingPlaceholderValue() const
-> const BindingPlaceholderValue& {
return std::get<BindingPlaceholderValue>(value);
}
auto Value::GetFunctionType() const -> const FunctionType& {
return std::get<FunctionType>(value);
}
auto Value::GetPointerType() const -> const PointerType& {
return std::get<PointerType>(value);
}
auto Value::GetStructType() const -> const StructType& {
return std::get<StructType>(value);
}
auto Value::GetChoiceType() const -> const ChoiceType& {
return std::get<ChoiceType>(value);
}
auto Value::GetContinuationValue() const -> const ContinuationValue& {
return std::get<ContinuationValue>(value);
}
auto FindInVarValues(const std::string& field, const VarValues& inits)
-> const Value* {
for (auto& i : inits) {
if (i.first == field) {
return i.second;
}
}
return nullptr;
}
auto FieldsEqual(const VarValues& ts1, const VarValues& ts2) -> bool {
if (ts1.size() == ts2.size()) {
for (auto& iter1 : ts1) {
auto t2 = FindInVarValues(iter1.first, ts2);
if (t2 == nullptr) {
return false;
}
if (!TypeEqual(iter1.second, t2)) {
return false;
}
}
return true;
} else {
return false;
}
}
auto TupleValue::FindField(const std::string& name) const -> const Value* {
for (const TupleElement& element : elements) {
if (element.name == name) {
return element.value;
}
}
return nullptr;
}
auto Value::MakeIntValue(int i) -> const Value* {
auto* v = new Value();
v->value = IntValue({.value = i});
return v;
}
auto Value::MakeBoolValue(bool b) -> const Value* {
auto* v = new Value();
v->value = BoolValue({.value = b});
return v;
}
auto Value::MakeFunctionValue(std::string name, const Value* param,
const Statement* body) -> const Value* {
auto* v = new Value();
v->value =
FunctionValue({.name = std::move(name), .param = param, .body = body});
return v;
}
auto Value::MakePointerValue(Address addr) -> const Value* {
auto* v = new Value();
v->value = PointerValue({.value = addr});
return v;
}
auto Value::MakeStructValue(const Value* type, const Value* inits)
-> const Value* {
auto* v = new Value();
v->value = StructValue({.type = type, .inits = inits});
return v;
}
auto Value::MakeTupleValue(std::vector<TupleElement> elements) -> const Value* {
auto* v = new Value();
v->value = TupleValue({.elements = std::move(elements)});
return v;
}
auto Value::MakeAlternativeValue(std::string alt_name, std::string choice_name,
const Value* argument) -> const Value* {
auto* v = new Value();
v->value = AlternativeValue({.alt_name = std::move(alt_name),
.choice_name = std::move(choice_name),
.argument = argument});
return v;
}
auto Value::MakeAlternativeConstructorValue(std::string alt_name,
std::string choice_name)
-> const Value* {
auto* v = new Value();
v->value = AlternativeConstructorValue(
{.alt_name = std::move(alt_name), .choice_name = std::move(choice_name)});
return v;
}
// Return a first-class continuation represented a fragment
// of the stack.
auto Value::MakeContinuationValue(std::vector<Frame*> stack) -> Value* {
auto* v = new Value();
v->value = ContinuationValue({.stack = std::move(stack)});
return v;
}
auto Value::MakeBindingPlaceholderValue(std::string name, const Value* type)
-> const Value* {
auto* v = new Value();
v->value = BindingPlaceholderValue({.name = std::move(name), .type = type});
return v;
}
auto Value::MakeIntType() -> const Value* {
auto* v = new Value();
v->value = IntType();
return v;
}
auto Value::MakeBoolType() -> const Value* {
auto* v = new Value();
v->value = BoolType();
return v;
}
auto Value::MakeTypeType() -> const Value* {
auto* v = new Value();
v->value = TypeType();
return v;
}
// Return a Continuation type.
auto Value::MakeContinuationType() -> const Value* {
auto* v = new Value();
v->value = ContinuationType();
return v;
}
auto Value::MakeAutoType() -> const Value* {
auto* v = new Value();
v->value = AutoType();
return v;
}
auto Value::MakeFunctionType(const Value* param, const Value* ret)
-> const Value* {
auto* v = new Value();
v->value = FunctionType({.param = param, .ret = ret});
return v;
}
auto Value::MakePointerType(const Value* type) -> const Value* {
auto* v = new Value();
v->value = PointerType({.type = type});
return v;
}
auto Value::MakeStructType(std::string name, VarValues fields,
VarValues methods) -> const Value* {
auto* v = new Value();
v->value = StructType({.name = std::move(name),
.fields = std::move(fields),
.methods = std::move(methods)});
return v;
}
auto Value::MakeUnitTypeVal() -> const Value* {
auto* v = new Value();
v->value = TupleValue({.elements = {}});
return v;
}
auto Value::MakeChoiceType(std::string name, VarValues alts) -> const Value* {
auto* v = new Value();
v->value =
ChoiceType({.name = std::move(name), .alternatives = std::move(alts)});
return v;
}
namespace {
auto GetMember(const Value* v, const std::string& f, int line_num)
-> const Value* {
switch (v->tag()) {
case ValKind::StructValue: {
const Value* field =
v->GetStructValue().inits->GetTupleValue().FindField(f);
if (field == nullptr) {
std::cerr << "runtime error, member " << f << " not in ";
PrintValue(v, std::cerr);
std::cerr << std::endl;
exit(-1);
}
return field;
}
case ValKind::TupleValue: {
const Value* field = v->GetTupleValue().FindField(f);
if (field == nullptr) {
std::cerr << "field " << f << " not in ";
PrintValue(v, std::cerr);
std::cerr << std::endl;
exit(-1);
}
return field;
}
case ValKind::ChoiceType: {
if (FindInVarValues(f, v->GetChoiceType().alternatives) == nullptr) {
std::cerr << "alternative " << f << " not in ";
PrintValue(v, std::cerr);
std::cerr << std::endl;
exit(-1);
}
return Value::MakeAlternativeConstructorValue(f, v->GetChoiceType().name);
}
default:
std::cerr << "field access not allowed for value ";
PrintValue(v, std::cerr);
std::cerr << std::endl;
exit(-1);
}
}
} // namespace
auto Value::GetField(const FieldPath& path, int line_num) const
-> const Value* {
const Value* value = this;
for (const std::string& field : path.components) {
value = GetMember(value, field, line_num);
}
return value;
}
namespace {
auto SetFieldImpl(const Value* value,
std::vector<std::string>::const_iterator path_begin,
std::vector<std::string>::const_iterator path_end,
const Value* field_value, int line_num) -> const Value* {
if (path_begin == path_end) {
return field_value;
}
switch (value->tag()) {
case ValKind::StructValue: {
return SetFieldImpl(value->GetStructValue().inits, path_begin, path_end,
field_value, line_num);
}
case ValKind::TupleValue: {
std::vector<TupleElement> elements = value->GetTupleValue().elements;
auto it = std::find_if(elements.begin(), elements.end(),
[path_begin](const TupleElement& element) {
return element.name == *path_begin;
});
if (it == elements.end()) {
std::cerr << "field " << *path_begin << " not in ";
PrintValue(value, std::cerr);
std::cerr << std::endl;
exit(-1);
}
it->value = SetFieldImpl(it->value, path_begin + 1, path_end, field_value,
line_num);
return Value::MakeTupleValue(elements);
}
default:
std::cerr << "field access not allowed for value ";
PrintValue(value, std::cerr);
std::cerr << std::endl;
exit(-1);
}
}
} // namespace
auto Value::SetField(const FieldPath& path, const Value* field_value,
int line_num) const -> const Value* {
return SetFieldImpl(this, path.components.begin(), path.components.end(),
field_value, line_num);
}
auto PrintValue(const Value* val, std::ostream& out) -> void {
switch (val->tag()) {
case ValKind::AlternativeConstructorValue: {
out << val->GetAlternativeConstructorValue().choice_name << "."
<< val->GetAlternativeConstructorValue().alt_name;
break;
}
case ValKind::BindingPlaceholderValue: {
PrintValue(val->GetBindingPlaceholderValue().type, out);
out << ": " << val->GetBindingPlaceholderValue().name;
break;
}
case ValKind::AlternativeValue: {
out << "alt " << val->GetAlternativeValue().choice_name << "."
<< val->GetAlternativeValue().alt_name << " ";
PrintValue(val->GetAlternativeValue().argument, out);
break;
}
case ValKind::StructValue: {
out << val->GetStructValue().type->GetStructType().name;
PrintValue(val->GetStructValue().inits, out);
break;
}
case ValKind::TupleValue: {
out << "(";
bool add_commas = false;
for (const TupleElement& element : val->GetTupleValue().elements) {
if (add_commas) {
out << ", ";
} else {
add_commas = true;
}
out << element.name << " = ";
PrintValue(element.value, out);
}
out << ")";
break;
}
case ValKind::IntValue:
out << val->GetIntValue();
break;
case ValKind::BoolValue:
out << std::boolalpha << val->GetBoolValue();
break;
case ValKind::FunctionValue:
out << "fun<" << val->GetFunctionValue().name << ">";
break;
case ValKind::PointerValue:
out << "ptr<" << val->GetPointerValue() << ">";
break;
case ValKind::BoolType:
out << "Bool";
break;
case ValKind::IntType:
out << "Int";
break;
case ValKind::TypeType:
out << "Type";
break;
case ValKind::AutoType:
out << "auto";
break;
case ValKind::ContinuationType:
out << "Continuation";
break;
case ValKind::PointerType:
PrintValue(val->GetPointerType().type, out);
out << "*";
break;
case ValKind::FunctionType:
out << "fn ";
PrintValue(val->GetFunctionType().param, out);
out << " -> ";
PrintValue(val->GetFunctionType().ret, out);
break;
case ValKind::StructType:
out << "struct " << val->GetStructType().name;
break;
case ValKind::ChoiceType:
out << "choice " << val->GetChoiceType().name;
break;
case ValKind::ContinuationValue:
out << "continuation[[";
for (Frame* frame : val->GetContinuationValue().stack) {
PrintFrame(frame, out);
out << " :: ";
}
out << "]]";
break;
}
}
auto TypeEqual(const Value* t1, const Value* t2) -> bool {
if (t1->tag() != t2->tag()) {
return false;
}
switch (t1->tag()) {
case ValKind::PointerType:
return TypeEqual(t1->GetPointerType().type, t2->GetPointerType().type);
case ValKind::FunctionType:
return TypeEqual(t1->GetFunctionType().param,
t2->GetFunctionType().param) &&
TypeEqual(t1->GetFunctionType().ret, t2->GetFunctionType().ret);
case ValKind::StructType:
return t1->GetStructType().name == t2->GetStructType().name;
case ValKind::ChoiceType:
return t1->GetChoiceType().name == t2->GetChoiceType().name;
case ValKind::TupleValue: {
if (t1->GetTupleValue().elements.size() !=
t2->GetTupleValue().elements.size()) {
return false;
}
for (size_t i = 0; i < t1->GetTupleValue().elements.size(); ++i) {
if (t1->GetTupleValue().elements[i].name !=
t2->GetTupleValue().elements[i].name) {
return false;
}
if (!TypeEqual(t1->GetTupleValue().elements[i].value,
t2->GetTupleValue().elements[i].value)) {
return false;
}
}
return true;
}
case ValKind::IntType:
case ValKind::BoolType:
case ValKind::ContinuationType:
case ValKind::TypeType:
return true;
default:
std::cerr << "TypeEqual used to compare non-type values" << std::endl;
PrintValue(t1, std::cerr);
std::cerr << std::endl;
PrintValue(t2, std::cerr);
exit(-1);
}
}
// Returns true if all the fields of the two tuples contain equal values
// and returns false otherwise.
static auto FieldsValueEqual(const std::vector<TupleElement>& ts1,
const std::vector<TupleElement>& ts2, int line_num)
-> bool {
if (ts1.size() != ts2.size()) {
return false;
}
for (const TupleElement& element : ts1) {
auto iter = std::find_if(
ts2.begin(), ts2.end(),
[&](const TupleElement& e2) { return e2.name == element.name; });
if (iter == ts2.end()) {
return false;
}
if (!ValueEqual(element.value, iter->value, line_num)) {
return false;
}
}
return true;
}
// Returns true if the two values are equal and returns false otherwise.
//
// This function implements the `==` operator of Carbon.
auto ValueEqual(const Value* v1, const Value* v2, int line_num) -> bool {
if (v1->tag() != v2->tag()) {
return false;
}
switch (v1->tag()) {
case ValKind::IntValue:
return v1->GetIntValue() == v2->GetIntValue();
case ValKind::BoolValue:
return v1->GetBoolValue() == v2->GetBoolValue();
case ValKind::PointerValue:
return v1->GetPointerValue() == v2->GetPointerValue();
case ValKind::FunctionValue:
return v1->GetFunctionValue().body == v2->GetFunctionValue().body;
case ValKind::TupleValue:
return FieldsValueEqual(v1->GetTupleValue().elements,
v2->GetTupleValue().elements, line_num);
default:
case ValKind::IntType:
case ValKind::BoolType:
case ValKind::TypeType:
case ValKind::FunctionType:
case ValKind::PointerType:
case ValKind::AutoType:
case ValKind::StructType:
case ValKind::ChoiceType:
case ValKind::ContinuationType:
return TypeEqual(v1, v2);
case ValKind::StructValue:
case ValKind::AlternativeValue:
case ValKind::BindingPlaceholderValue:
case ValKind::AlternativeConstructorValue:
case ValKind::ContinuationValue:
std::cerr << "ValueEqual does not support this kind of value."
<< std::endl;
exit(-1);
}
}
} // namespace Carbon