mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-25 08:40:10 +01:00
Jon MeowandGeoff Romer
9007bfcb88
`// NOLINT` is added on type aliases in stack.h and dictionary.h to allow lower_snake_case naming -- this didn't feel like a check worth disabling in spite of false positives. Co-authored-by: Geoff Romer <gromer@google.com>
1235 lines
46 KiB
C++
1235 lines
46 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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#include "executable_semantics/interpreter/interpreter.h"
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#include <iterator>
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#include <map>
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#include <optional>
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#include <utility>
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#include <variant>
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#include <vector>
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#include "common/check.h"
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#include "executable_semantics/ast/expression.h"
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#include "executable_semantics/ast/function_definition.h"
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#include "executable_semantics/common/arena.h"
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#include "executable_semantics/common/error.h"
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#include "executable_semantics/common/tracing_flag.h"
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#include "executable_semantics/interpreter/action.h"
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#include "executable_semantics/interpreter/frame.h"
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#include "executable_semantics/interpreter/stack.h"
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#include "llvm/ADT/ScopeExit.h"
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#include "llvm/ADT/StringExtras.h"
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#include "llvm/Support/Casting.h"
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using llvm::cast;
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using llvm::dyn_cast;
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namespace Carbon {
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//
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// Auxiliary Functions
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//
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void Interpreter::PrintEnv(Env values, llvm::raw_ostream& out) {
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llvm::ListSeparator sep;
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for (const auto& [name, address] : values) {
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out << sep << name << ": ";
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heap.PrintAddress(address, out);
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}
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}
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//
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// State Operations
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//
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auto Interpreter::CurrentEnv() -> Env {
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Nonnull<Frame*> frame = stack.Top();
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return frame->scopes.Top()->values;
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}
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// Returns the given name from the environment, printing an error if not found.
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auto Interpreter::GetFromEnv(SourceLocation source_loc, const std::string& name)
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-> Address {
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std::optional<Address> pointer = CurrentEnv().Get(name);
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if (!pointer) {
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FATAL_RUNTIME_ERROR(source_loc) << "could not find `" << name << "`";
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}
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return *pointer;
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}
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void Interpreter::PrintState(llvm::raw_ostream& out) {
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out << "{\nstack: ";
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llvm::ListSeparator sep(" :: ");
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for (const auto& frame : stack) {
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out << sep << *frame;
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}
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out << "\nheap: " << heap;
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if (!stack.IsEmpty() && !stack.Top()->scopes.IsEmpty()) {
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out << "\nvalues: ";
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PrintEnv(CurrentEnv(), out);
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}
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out << "\n}\n";
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}
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auto Interpreter::EvalPrim(Operator op,
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const std::vector<Nonnull<const Value*>>& args,
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SourceLocation source_loc) -> Nonnull<const Value*> {
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switch (op) {
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case Operator::Neg:
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return arena->New<IntValue>(-cast<IntValue>(*args[0]).Val());
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case Operator::Add:
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return arena->New<IntValue>(cast<IntValue>(*args[0]).Val() +
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cast<IntValue>(*args[1]).Val());
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case Operator::Sub:
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return arena->New<IntValue>(cast<IntValue>(*args[0]).Val() -
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cast<IntValue>(*args[1]).Val());
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case Operator::Mul:
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return arena->New<IntValue>(cast<IntValue>(*args[0]).Val() *
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cast<IntValue>(*args[1]).Val());
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case Operator::Not:
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return arena->New<BoolValue>(!cast<BoolValue>(*args[0]).Val());
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case Operator::And:
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return arena->New<BoolValue>(cast<BoolValue>(*args[0]).Val() &&
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cast<BoolValue>(*args[1]).Val());
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case Operator::Or:
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return arena->New<BoolValue>(cast<BoolValue>(*args[0]).Val() ||
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cast<BoolValue>(*args[1]).Val());
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case Operator::Eq:
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return arena->New<BoolValue>(ValueEqual(args[0], args[1], source_loc));
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case Operator::Ptr:
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return arena->New<PointerType>(args[0]);
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case Operator::Deref:
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FATAL() << "dereference not implemented yet";
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}
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}
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void Interpreter::InitEnv(const Declaration& d, Env* env) {
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switch (d.kind()) {
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case Declaration::Kind::FunctionDeclaration: {
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const FunctionDefinition& func_def =
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cast<FunctionDeclaration>(d).definition();
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Env new_env = *env;
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// Bring the deduced parameters into scope.
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for (const auto& deduced : func_def.deduced_parameters()) {
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Address a = heap.AllocateValue(arena->New<VariableType>(deduced.name));
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new_env.Set(deduced.name, a);
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}
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auto pt = InterpPattern(new_env, &func_def.param_pattern());
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auto f = arena->New<FunctionValue>(func_def.name(), pt, func_def.body());
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Address a = heap.AllocateValue(f);
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env->Set(func_def.name(), a);
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break;
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}
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case Declaration::Kind::ClassDeclaration: {
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const ClassDefinition& class_def = cast<ClassDeclaration>(d).definition();
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VarValues fields;
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VarValues methods;
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for (Nonnull<const Member*> m : class_def.members()) {
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switch (m->kind()) {
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case Member::Kind::FieldMember: {
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Nonnull<const BindingPattern*> binding =
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cast<FieldMember>(*m).Binding();
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Nonnull<const Expression*> type_expression =
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cast<ExpressionPattern>(*binding->Type()).Expression();
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auto type = InterpExp(Env(arena), type_expression);
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fields.push_back(make_pair(*binding->Name(), type));
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break;
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}
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}
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}
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auto st = arena->New<NominalClassType>(
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class_def.name(), std::move(fields), std::move(methods));
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auto a = heap.AllocateValue(st);
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env->Set(class_def.name(), a);
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break;
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}
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case Declaration::Kind::ChoiceDeclaration: {
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const auto& choice = cast<ChoiceDeclaration>(d);
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VarValues alts;
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for (const auto& alternative : choice.alternatives()) {
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auto t = InterpExp(Env(arena), &alternative.signature());
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alts.push_back(make_pair(alternative.name(), t));
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}
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auto ct = arena->New<ChoiceType>(choice.name(), std::move(alts));
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auto a = heap.AllocateValue(ct);
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env->Set(choice.name(), a);
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break;
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}
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case Declaration::Kind::VariableDeclaration: {
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const auto& var = cast<VariableDeclaration>(d);
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// Adds an entry in `globals` mapping the variable's name to the
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// result of evaluating the initializer.
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auto v = InterpExp(*env, &var.initializer());
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Address a = heap.AllocateValue(v);
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env->Set(*var.binding().Name(), a);
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break;
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}
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}
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}
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void Interpreter::InitGlobals(llvm::ArrayRef<Nonnull<Declaration*>> fs) {
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for (const auto d : fs) {
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InitEnv(*d, &globals);
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}
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}
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void Interpreter::DeallocateScope(Nonnull<Scope*> scope) {
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for (const auto& l : scope->locals) {
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std::optional<Address> a = scope->values.Get(l);
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CHECK(a);
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heap.Deallocate(*a);
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}
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}
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void Interpreter::DeallocateLocals(Nonnull<Frame*> frame) {
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while (!frame->scopes.IsEmpty()) {
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DeallocateScope(frame->scopes.Top());
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frame->scopes.Pop();
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}
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}
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auto Interpreter::CreateTuple(Nonnull<Action*> act,
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Nonnull<const Expression*> exp)
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-> Nonnull<const Value*> {
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// { { (v1,...,vn) :: C, E, F} :: S, H}
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// -> { { `(v1,...,vn) :: C, E, F} :: S, H}
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const auto& tup_lit = cast<TupleLiteral>(*exp);
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CHECK(act->results().size() == tup_lit.fields().size());
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std::vector<TupleElement> elements;
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for (size_t i = 0; i < act->results().size(); ++i) {
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elements.push_back(
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{.name = tup_lit.fields()[i].name(), .value = act->results()[i]});
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}
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return arena->New<TupleValue>(std::move(elements));
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}
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auto Interpreter::CreateStruct(const std::vector<FieldInitializer>& fields,
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const std::vector<Nonnull<const Value*>>& values)
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-> Nonnull<const Value*> {
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CHECK(fields.size() == values.size());
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std::vector<TupleElement> elements;
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for (size_t i = 0; i < fields.size(); ++i) {
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elements.push_back({.name = fields[i].name(), .value = values[i]});
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}
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return arena->New<StructValue>(std::move(elements));
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}
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auto Interpreter::PatternMatch(Nonnull<const Value*> p, Nonnull<const Value*> v,
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SourceLocation source_loc)
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-> std::optional<Env> {
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switch (p->kind()) {
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case Value::Kind::BindingPlaceholderValue: {
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const auto& placeholder = cast<BindingPlaceholderValue>(*p);
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Env values(arena);
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if (placeholder.Name().has_value()) {
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Address a = heap.AllocateValue(CopyVal(arena, v, source_loc));
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values.Set(*placeholder.Name(), a);
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}
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return values;
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}
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case Value::Kind::TupleValue:
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switch (v->kind()) {
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case Value::Kind::TupleValue: {
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const auto& p_tup = cast<TupleValue>(*p);
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const auto& v_tup = cast<TupleValue>(*v);
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if (p_tup.Elements().size() != v_tup.Elements().size()) {
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FATAL_PROGRAM_ERROR(source_loc)
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<< "arity mismatch in tuple pattern match:\n pattern: "
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<< p_tup << "\n value: " << v_tup;
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}
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Env values(arena);
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for (size_t i = 0; i < p_tup.Elements().size(); ++i) {
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if (p_tup.Elements()[i].name != v_tup.Elements()[i].name) {
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FATAL_PROGRAM_ERROR(source_loc)
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<< "Tuple field name '" << v_tup.Elements()[i].name
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<< "' does not match pattern field name '"
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<< p_tup.Elements()[i].name << "'";
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}
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std::optional<Env> matches =
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PatternMatch(p_tup.Elements()[i].value,
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v_tup.Elements()[i].value, source_loc);
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if (!matches) {
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return std::nullopt;
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}
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for (const auto& [name, value] : *matches) {
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values.Set(name, value);
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}
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} // for
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return values;
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}
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default:
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FATAL() << "expected a tuple value in pattern, not " << *v;
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}
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case Value::Kind::StructValue: {
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const auto& p_struct = cast<StructValue>(*p);
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const auto& v_struct = cast<StructValue>(*v);
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CHECK(p_struct.elements().size() == v_struct.elements().size());
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Env values(arena);
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for (size_t i = 0; i < p_struct.elements().size(); ++i) {
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CHECK(p_struct.elements()[i].name == v_struct.elements()[i].name);
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std::optional<Env> matches =
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PatternMatch(p_struct.elements()[i].value,
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v_struct.elements()[i].value, source_loc);
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if (!matches) {
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return std::nullopt;
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}
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for (const auto& [name, value] : *matches) {
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values.Set(name, value);
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}
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}
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return values;
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}
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case Value::Kind::AlternativeValue:
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switch (v->kind()) {
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case Value::Kind::AlternativeValue: {
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const auto& p_alt = cast<AlternativeValue>(*p);
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const auto& v_alt = cast<AlternativeValue>(*v);
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if (p_alt.ChoiceName() != v_alt.ChoiceName() ||
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p_alt.AltName() != v_alt.AltName()) {
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return std::nullopt;
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}
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return PatternMatch(p_alt.Argument(), v_alt.Argument(), source_loc);
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}
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default:
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FATAL() << "expected a choice alternative in pattern, not " << *v;
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}
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case Value::Kind::FunctionType:
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switch (v->kind()) {
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case Value::Kind::FunctionType: {
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const auto& p_fn = cast<FunctionType>(*p);
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const auto& v_fn = cast<FunctionType>(*v);
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std::optional<Env> param_matches =
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PatternMatch(p_fn.Param(), v_fn.Param(), source_loc);
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if (!param_matches) {
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return std::nullopt;
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}
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std::optional<Env> ret_matches =
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PatternMatch(p_fn.Ret(), v_fn.Ret(), source_loc);
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if (!ret_matches) {
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return std::nullopt;
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}
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Env values = *param_matches;
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for (const auto& [name, value] : *ret_matches) {
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values.Set(name, value);
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}
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return values;
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}
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default:
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return std::nullopt;
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}
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case Value::Kind::AutoType:
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// `auto` matches any type, without binding any new names. We rely
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// on the typechecker to ensure that `v` is a type.
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return Env(arena);
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default:
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if (ValueEqual(p, v, source_loc)) {
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return Env(arena);
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} else {
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return std::nullopt;
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}
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}
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}
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void Interpreter::PatternAssignment(Nonnull<const Value*> pat,
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Nonnull<const Value*> val,
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SourceLocation source_loc) {
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switch (pat->kind()) {
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case Value::Kind::PointerValue:
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heap.Write(cast<PointerValue>(*pat).Val(),
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CopyVal(arena, val, source_loc), source_loc);
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break;
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case Value::Kind::TupleValue: {
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switch (val->kind()) {
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case Value::Kind::TupleValue: {
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const auto& pat_tup = cast<TupleValue>(*pat);
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const auto& val_tup = cast<TupleValue>(*val);
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if (pat_tup.Elements().size() != val_tup.Elements().size()) {
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FATAL_RUNTIME_ERROR(source_loc)
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<< "arity mismatch in tuple pattern assignment:\n pattern: "
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<< pat_tup << "\n value: " << val_tup;
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}
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for (const TupleElement& pattern_element : pat_tup.Elements()) {
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std::optional<Nonnull<const Value*>> value_field =
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val_tup.FindField(pattern_element.name);
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if (!value_field) {
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FATAL_RUNTIME_ERROR(source_loc)
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<< "field " << pattern_element.name << "not in " << *val;
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}
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PatternAssignment(pattern_element.value, *value_field, source_loc);
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}
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break;
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}
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default:
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FATAL() << "expected a tuple value on right-hand-side, not " << *val;
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}
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break;
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}
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case Value::Kind::AlternativeValue: {
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switch (val->kind()) {
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case Value::Kind::AlternativeValue: {
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const auto& pat_alt = cast<AlternativeValue>(*pat);
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const auto& val_alt = cast<AlternativeValue>(*val);
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CHECK(val_alt.ChoiceName() == pat_alt.ChoiceName() &&
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val_alt.AltName() == pat_alt.AltName())
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<< "internal error in pattern assignment";
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PatternAssignment(pat_alt.Argument(), val_alt.Argument(), source_loc);
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break;
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}
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default:
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FATAL() << "expected an alternative in left-hand-side, not " << *val;
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}
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break;
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}
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default:
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CHECK(ValueEqual(pat, val, source_loc))
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<< "internal error in pattern assignment";
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}
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}
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auto Interpreter::StepLvalue() -> Transition {
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Nonnull<Action*> act = stack.Top()->todo.Top();
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Nonnull<const Expression*> exp = cast<LValAction>(*act).Exp();
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if (tracing_output) {
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llvm::outs() << "--- step lvalue " << *exp << " (" << exp->source_loc()
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<< ") --->\n";
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}
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switch (exp->kind()) {
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case Expression::Kind::IdentifierExpression: {
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// { {x :: C, E, F} :: S, H}
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// -> { {E(x) :: C, E, F} :: S, H}
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Address pointer = GetFromEnv(exp->source_loc(),
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cast<IdentifierExpression>(*exp).name());
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Nonnull<const Value*> v = arena->New<PointerValue>(pointer);
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return Done{v};
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}
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case Expression::Kind::FieldAccessExpression: {
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if (act->pos() == 0) {
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// { {e.f :: C, E, F} :: S, H}
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// -> { e :: [].f :: C, E, F} :: S, H}
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return Spawn{arena->New<LValAction>(
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&cast<FieldAccessExpression>(*exp).aggregate())};
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} else {
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// { v :: [].f :: C, E, F} :: S, H}
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// -> { { &v.f :: C, E, F} :: S, H }
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Address aggregate = cast<PointerValue>(*act->results()[0]).Val();
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Address field = aggregate.SubobjectAddress(
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cast<FieldAccessExpression>(*exp).field());
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return Done{arena->New<PointerValue>(field)};
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}
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}
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case Expression::Kind::IndexExpression: {
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if (act->pos() == 0) {
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// { {e[i] :: C, E, F} :: S, H}
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// -> { e :: [][i] :: C, E, F} :: S, H}
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return Spawn{
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arena->New<LValAction>(&cast<IndexExpression>(*exp).aggregate())};
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} else if (act->pos() == 1) {
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return Spawn{arena->New<ExpressionAction>(
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&cast<IndexExpression>(*exp).offset())};
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} else {
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// { v :: [][i] :: C, E, F} :: S, H}
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// -> { { &v[i] :: C, E, F} :: S, H }
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Address aggregate = cast<PointerValue>(*act->results()[0]).Val();
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std::string f =
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std::to_string(cast<IntValue>(*act->results()[1]).Val());
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Address field = aggregate.SubobjectAddress(f);
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return Done{arena->New<PointerValue>(field)};
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}
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}
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case Expression::Kind::TupleLiteral: {
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if (act->pos() <
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static_cast<int>(cast<TupleLiteral>(*exp).fields().size())) {
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// { { vk :: (f1=v1,..., fk=[],fk+1=ek+1,...) :: C, E, F} :: S,
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// H}
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// -> { { ek+1 :: (f1=v1,..., fk=vk, fk+1=[],...) :: C, E, F} :: S,
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// H}
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return Spawn{arena->New<LValAction>(
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&cast<TupleLiteral>(*exp).fields()[act->pos()].expression())};
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} else {
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return Done{CreateTuple(act, exp)};
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}
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}
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case Expression::Kind::StructLiteral:
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case Expression::Kind::StructTypeLiteral:
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case Expression::Kind::IntLiteral:
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case Expression::Kind::BoolLiteral:
|
|
case Expression::Kind::CallExpression:
|
|
case Expression::Kind::PrimitiveOperatorExpression:
|
|
case Expression::Kind::IntTypeLiteral:
|
|
case Expression::Kind::BoolTypeLiteral:
|
|
case Expression::Kind::TypeTypeLiteral:
|
|
case Expression::Kind::FunctionTypeLiteral:
|
|
case Expression::Kind::ContinuationTypeLiteral:
|
|
case Expression::Kind::StringLiteral:
|
|
case Expression::Kind::StringTypeLiteral:
|
|
case Expression::Kind::IntrinsicExpression:
|
|
FATAL_RUNTIME_ERROR_NO_LINE()
|
|
<< "Can't treat expression as lvalue: " << *exp;
|
|
}
|
|
}
|
|
|
|
auto Interpreter::StepExp() -> Transition {
|
|
Nonnull<Action*> act = stack.Top()->todo.Top();
|
|
Nonnull<const Expression*> exp = cast<ExpressionAction>(*act).Exp();
|
|
if (tracing_output) {
|
|
llvm::outs() << "--- step exp " << *exp << " (" << exp->source_loc()
|
|
<< ") --->\n";
|
|
}
|
|
switch (exp->kind()) {
|
|
case Expression::Kind::IndexExpression: {
|
|
if (act->pos() == 0) {
|
|
// { { e[i] :: C, E, F} :: S, H}
|
|
// -> { { e :: [][i] :: C, E, F} :: S, H}
|
|
return Spawn{arena->New<ExpressionAction>(
|
|
&cast<IndexExpression>(*exp).aggregate())};
|
|
} else if (act->pos() == 1) {
|
|
return Spawn{arena->New<ExpressionAction>(
|
|
&cast<IndexExpression>(*exp).offset())};
|
|
} else {
|
|
// { { v :: [][i] :: C, E, F} :: S, H}
|
|
// -> { { v_i :: C, E, F} : S, H}
|
|
auto* tuple = dyn_cast<TupleValue>(act->results()[0]);
|
|
if (tuple == nullptr) {
|
|
FATAL_RUNTIME_ERROR_NO_LINE()
|
|
<< "expected a tuple in field access, not " << *act->results()[0];
|
|
}
|
|
std::string f =
|
|
std::to_string(cast<IntValue>(*act->results()[1]).Val());
|
|
std::optional<Nonnull<const Value*>> field = tuple->FindField(f);
|
|
if (!field) {
|
|
FATAL_RUNTIME_ERROR_NO_LINE()
|
|
<< "field " << f << " not in " << *tuple;
|
|
}
|
|
return Done{*field};
|
|
}
|
|
}
|
|
case Expression::Kind::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{arena->New<ExpressionAction>(
|
|
&cast<TupleLiteral>(*exp).fields()[act->pos()].expression())};
|
|
} else {
|
|
return Done{CreateTuple(act, exp)};
|
|
}
|
|
}
|
|
case Expression::Kind::StructLiteral: {
|
|
const auto& literal = cast<StructLiteral>(*exp);
|
|
if (act->pos() < static_cast<int>(literal.fields().size())) {
|
|
return Spawn{arena->New<ExpressionAction>(
|
|
&literal.fields()[act->pos()].expression())};
|
|
} else {
|
|
return Done{CreateStruct(literal.fields(), act->results())};
|
|
}
|
|
}
|
|
case Expression::Kind::StructTypeLiteral: {
|
|
const auto& struct_type = cast<StructTypeLiteral>(*exp);
|
|
if (act->pos() < static_cast<int>(struct_type.fields().size())) {
|
|
return Spawn{arena->New<ExpressionAction>(
|
|
&struct_type.fields()[act->pos()].expression())};
|
|
} else {
|
|
VarValues 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 Expression::Kind::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{arena->New<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 Expression::Kind::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 Expression::Kind::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 Expression::Kind::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 Expression::Kind::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{arena->New<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 Expression::Kind::CallExpression:
|
|
if (act->pos() == 0) {
|
|
// { {e1(e2) :: C, E, F} :: S, H}
|
|
// -> { {e1 :: [](e2) :: C, E, F} :: S, H}
|
|
return Spawn{arena->New<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{arena->New<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::NominalClassType: {
|
|
Nonnull<const Value*> arg =
|
|
CopyVal(arena, act->results()[1], exp->source_loc());
|
|
return Done{arena->New<NominalClassValue>(act->results()[0], arg)};
|
|
}
|
|
case Value::Kind::AlternativeConstructorValue: {
|
|
const auto& alt =
|
|
cast<AlternativeConstructorValue>(*act->results()[0]);
|
|
Nonnull<const Value*> arg =
|
|
CopyVal(arena, act->results()[1], exp->source_loc());
|
|
return Done{arena->New<AlternativeValue>(alt.AltName(),
|
|
alt.ChoiceName(), arg)};
|
|
}
|
|
case Value::Kind::FunctionValue:
|
|
return CallFunction{
|
|
// TODO: Think about a cleaner way to cast between Ptr types.
|
|
// (multiple TODOs)
|
|
.function = Nonnull<const FunctionValue*>(
|
|
cast<FunctionValue>(act->results()[0])),
|
|
.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 {
|
|
FATAL() << "in handle_value with Call pos " << act->pos();
|
|
}
|
|
case Expression::Kind::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).Val();
|
|
return Done{TupleValue::Empty()};
|
|
}
|
|
|
|
case Expression::Kind::IntTypeLiteral: {
|
|
CHECK(act->pos() == 0);
|
|
return Done{arena->New<IntType>()};
|
|
}
|
|
case Expression::Kind::BoolTypeLiteral: {
|
|
CHECK(act->pos() == 0);
|
|
return Done{arena->New<BoolType>()};
|
|
}
|
|
case Expression::Kind::TypeTypeLiteral: {
|
|
CHECK(act->pos() == 0);
|
|
return Done{arena->New<TypeType>()};
|
|
}
|
|
case Expression::Kind::FunctionTypeLiteral: {
|
|
if (act->pos() == 0) {
|
|
return Spawn{arena->New<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{arena->New<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<GenericBinding>(),
|
|
act->results()[0],
|
|
act->results()[1])};
|
|
}
|
|
}
|
|
case Expression::Kind::ContinuationTypeLiteral: {
|
|
CHECK(act->pos() == 0);
|
|
return Done{arena->New<ContinuationType>()};
|
|
}
|
|
case Expression::Kind::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 Expression::Kind::StringTypeLiteral: {
|
|
CHECK(act->pos() == 0);
|
|
return Done{arena->New<StringType>()};
|
|
}
|
|
} // switch (exp->kind)
|
|
}
|
|
|
|
auto Interpreter::StepPattern() -> Transition {
|
|
Nonnull<Action*> act = stack.Top()->todo.Top();
|
|
Nonnull<const Pattern*> pattern = cast<PatternAction>(*act).Pat();
|
|
if (tracing_output) {
|
|
llvm::outs() << "--- step pattern " << *pattern << " ("
|
|
<< pattern->source_loc() << ") --->\n";
|
|
}
|
|
switch (pattern->kind()) {
|
|
case Pattern::Kind::AutoPattern: {
|
|
CHECK(act->pos() == 0);
|
|
return Done{arena->New<AutoType>()};
|
|
}
|
|
case Pattern::Kind::BindingPattern: {
|
|
const auto& binding = cast<BindingPattern>(*pattern);
|
|
if (act->pos() == 0) {
|
|
return Spawn{arena->New<PatternAction>(binding.Type())};
|
|
} else {
|
|
return Done{arena->New<BindingPlaceholderValue>(binding.Name(),
|
|
act->results()[0])};
|
|
}
|
|
}
|
|
case Pattern::Kind::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{
|
|
arena->New<PatternAction>(tuple.Fields()[act->pos()].pattern)};
|
|
} else {
|
|
std::vector<TupleElement> elements;
|
|
for (size_t i = 0; i < tuple.Fields().size(); ++i) {
|
|
elements.push_back(
|
|
{.name = tuple.Fields()[i].name, .value = act->results()[i]});
|
|
}
|
|
return Done{arena->New<TupleValue>(std::move(elements))};
|
|
}
|
|
}
|
|
case Pattern::Kind::AlternativePattern: {
|
|
const auto& alternative = cast<AlternativePattern>(*pattern);
|
|
if (act->pos() == 0) {
|
|
return Spawn{arena->New<ExpressionAction>(alternative.ChoiceType())};
|
|
} else if (act->pos() == 1) {
|
|
return Spawn{arena->New<PatternAction>(alternative.Arguments())};
|
|
} else {
|
|
CHECK(act->pos() == 2);
|
|
const auto& choice_type = cast<ChoiceType>(*act->results()[0]);
|
|
return Done{arena->New<AlternativeValue>(alternative.AlternativeName(),
|
|
choice_type.Name(),
|
|
act->results()[1])};
|
|
}
|
|
}
|
|
case Pattern::Kind::ExpressionPattern:
|
|
return Delegate{arena->New<ExpressionAction>(
|
|
cast<ExpressionPattern>(*pattern).Expression())};
|
|
}
|
|
}
|
|
|
|
static auto IsWhileAct(Nonnull<Action*> act) -> bool {
|
|
switch (act->kind()) {
|
|
case Action::Kind::StatementAction:
|
|
switch (cast<StatementAction>(*act).Stmt()->kind()) {
|
|
case Statement::Kind::While:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
static auto HasLocalScope(Nonnull<Action*> act) -> bool {
|
|
switch (act->kind()) {
|
|
case Action::Kind::StatementAction:
|
|
switch (cast<StatementAction>(*act).Stmt()->kind()) {
|
|
case Statement::Kind::Block:
|
|
case Statement::Kind::Match:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
auto Interpreter::StepStmt() -> Transition {
|
|
Nonnull<Frame*> frame = stack.Top();
|
|
Nonnull<Action*> act = frame->todo.Top();
|
|
Nonnull<const Statement*> stmt = cast<StatementAction>(*act).Stmt();
|
|
if (tracing_output) {
|
|
llvm::outs() << "--- step stmt ";
|
|
stmt->PrintDepth(1, llvm::outs());
|
|
llvm::outs() << " (" << stmt->source_loc() << ") --->\n";
|
|
}
|
|
switch (stmt->kind()) {
|
|
case Statement::Kind::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}
|
|
frame->scopes.Push(arena->New<Scope>(CurrentEnv()));
|
|
return Spawn{arena->New<ExpressionAction>(&match_stmt.expression())};
|
|
} else {
|
|
// Regarding act->pos():
|
|
// * odd: start interpreting the pattern of a clause
|
|
// * even: finished interpreting the pattern, now try to match
|
|
//
|
|
// Regarding act->results():
|
|
// * 0: the value that we're matching
|
|
// * 1: the pattern for clause 0
|
|
// * 2: the pattern for clause 1
|
|
// * ...
|
|
auto clause_num = (act->pos() - 1) / 2;
|
|
if (clause_num >= static_cast<int>(match_stmt.clauses().size())) {
|
|
DeallocateScope(frame->scopes.Top());
|
|
frame->scopes.Pop();
|
|
return Done{};
|
|
}
|
|
auto c = match_stmt.clauses()[clause_num];
|
|
|
|
if (act->pos() % 2 == 1) {
|
|
// start interpreting the pattern of the clause
|
|
// { {v :: (match ([]) ...) :: C, E, F} :: S, H}
|
|
// -> { {pi :: (match ([]) ...) :: C, E, F} :: S, H}
|
|
return Spawn{arena->New<PatternAction>(&c.pattern())};
|
|
} else { // try to match
|
|
auto v = act->results()[0];
|
|
auto pat = act->results()[clause_num + 1];
|
|
std::optional<Env> matches = PatternMatch(pat, v, stmt->source_loc());
|
|
if (matches) { // we have a match, start the body
|
|
// Ensure we don't process any more clauses.
|
|
act->set_pos(2 * match_stmt.clauses().size() + 1);
|
|
|
|
for (const auto& [name, value] : *matches) {
|
|
frame->scopes.Top()->values.Set(name, value);
|
|
frame->scopes.Top()->locals.push_back(name);
|
|
}
|
|
return Spawn{arena->New<StatementAction>(&c.statement())};
|
|
} else {
|
|
return RunAgain{};
|
|
}
|
|
}
|
|
}
|
|
}
|
|
case Statement::Kind::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{arena->New<ExpressionAction>(cast<While>(*stmt).Cond())};
|
|
} else if (cast<BoolValue>(*act->results().back()).Val()) {
|
|
// { {true :: (while ([]) s) :: C, E, F} :: S, H}
|
|
// -> { { s :: (while (e) s) :: C, E, F } :: S, H}
|
|
return Spawn{arena->New<StatementAction>(cast<While>(*stmt).Body())};
|
|
} else {
|
|
// { {false :: (while ([]) s) :: C, E, F} :: S, H}
|
|
// -> { { C, E, F } :: S, H}
|
|
return Done{};
|
|
}
|
|
case Statement::Kind::Break: {
|
|
CHECK(act->pos() == 0);
|
|
// { { break; :: ... :: (while (e) s) :: C, E, F} :: S, H}
|
|
// -> { { C, E', F} :: S, H}
|
|
auto it =
|
|
std::find_if(frame->todo.begin(), frame->todo.end(), &IsWhileAct);
|
|
if (it == frame->todo.end()) {
|
|
FATAL_RUNTIME_ERROR(stmt->source_loc())
|
|
<< "`break` not inside `while` statement";
|
|
}
|
|
++it;
|
|
return UnwindTo{*it};
|
|
}
|
|
case Statement::Kind::Continue: {
|
|
CHECK(act->pos() == 0);
|
|
// { { continue; :: ... :: (while (e) s) :: C, E, F} :: S, H}
|
|
// -> { { (while (e) s) :: C, E', F} :: S, H}
|
|
auto it =
|
|
std::find_if(frame->todo.begin(), frame->todo.end(), &IsWhileAct);
|
|
if (it == frame->todo.end()) {
|
|
FATAL_RUNTIME_ERROR(stmt->source_loc())
|
|
<< "`continue` not inside `while` statement";
|
|
}
|
|
return UnwindTo{*it};
|
|
}
|
|
case Statement::Kind::Block: {
|
|
if (act->pos() == 0) {
|
|
const auto& block = cast<Block>(*stmt);
|
|
if (block.Stmt()) {
|
|
frame->scopes.Push(arena->New<Scope>(CurrentEnv()));
|
|
return Spawn{arena->New<StatementAction>(*block.Stmt())};
|
|
} else {
|
|
return Done{};
|
|
}
|
|
} else {
|
|
Nonnull<Scope*> scope = frame->scopes.Top();
|
|
DeallocateScope(scope);
|
|
frame->scopes.Pop(1);
|
|
return Done{};
|
|
}
|
|
}
|
|
case Statement::Kind::VariableDefinition:
|
|
if (act->pos() == 0) {
|
|
// { {(var x = e) :: C, E, F} :: S, H}
|
|
// -> { {e :: (var x = []) :: C, E, F} :: S, H}
|
|
return Spawn{arena->New<ExpressionAction>(
|
|
cast<VariableDefinition>(*stmt).Init())};
|
|
} else if (act->pos() == 1) {
|
|
return Spawn{
|
|
arena->New<PatternAction>(cast<VariableDefinition>(*stmt).Pat())};
|
|
} else {
|
|
// { { v :: (x = []) :: C, E, F} :: S, H}
|
|
// -> { { C, E(x := a), F} :: S, H(a := copy(v))}
|
|
Nonnull<const Value*> v = act->results()[0];
|
|
Nonnull<const Value*> p = act->results()[1];
|
|
|
|
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) {
|
|
frame->scopes.Top()->values.Set(name, value);
|
|
frame->scopes.Top()->locals.push_back(name);
|
|
}
|
|
return Done{};
|
|
}
|
|
case Statement::Kind::ExpressionStatement:
|
|
if (act->pos() == 0) {
|
|
// { {e :: C, E, F} :: S, H}
|
|
// -> { {e :: C, E, F} :: S, H}
|
|
return Spawn{arena->New<ExpressionAction>(
|
|
cast<ExpressionStatement>(*stmt).Exp())};
|
|
} else {
|
|
return Done{};
|
|
}
|
|
case Statement::Kind::Assign:
|
|
if (act->pos() == 0) {
|
|
// { {(lv = e) :: C, E, F} :: S, H}
|
|
// -> { {lv :: ([] = e) :: C, E, F} :: S, H}
|
|
return Spawn{arena->New<LValAction>(cast<Assign>(*stmt).Lhs())};
|
|
} else if (act->pos() == 1) {
|
|
// { { a :: ([] = e) :: C, E, F} :: S, H}
|
|
// -> { { e :: (a = []) :: C, E, F} :: S, H}
|
|
return Spawn{arena->New<ExpressionAction>(cast<Assign>(*stmt).Rhs())};
|
|
} else {
|
|
// { { v :: (a = []) :: C, E, F} :: S, H}
|
|
// -> { { C, E, F} :: S, H(a := v)}
|
|
auto pat = act->results()[0];
|
|
auto val = act->results()[1];
|
|
PatternAssignment(pat, val, stmt->source_loc());
|
|
return Done{};
|
|
}
|
|
case Statement::Kind::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{arena->New<ExpressionAction>(cast<If>(*stmt).Cond())};
|
|
} else if (cast<BoolValue>(*act->results()[0]).Val()) {
|
|
// { {true :: if ([]) then_stmt else else_stmt :: C, E, F} ::
|
|
// S, H}
|
|
// -> { { then_stmt :: C, E, F } :: S, H}
|
|
return Delegate{
|
|
arena->New<StatementAction>(cast<If>(*stmt).ThenStmt())};
|
|
} else if (cast<If>(*stmt).ElseStmt()) {
|
|
// { {false :: if ([]) then_stmt else else_stmt :: C, E, F} ::
|
|
// S, H}
|
|
// -> { { else_stmt :: C, E, F } :: S, H}
|
|
return Delegate{
|
|
arena->New<StatementAction>(*cast<If>(*stmt).ElseStmt())};
|
|
} else {
|
|
return Done{};
|
|
}
|
|
case Statement::Kind::Return:
|
|
if (act->pos() == 0) {
|
|
// { {return e :: C, E, F} :: S, H}
|
|
// -> { {e :: return [] :: C, E, F} :: S, H}
|
|
return Spawn{arena->New<ExpressionAction>(cast<Return>(*stmt).Exp())};
|
|
} else {
|
|
// { {v :: return [] :: C, E, F} :: {C', E', F'} :: S, H}
|
|
// -> { {v :: C', E', F'} :: S, H}
|
|
Nonnull<const Value*> ret_val =
|
|
CopyVal(arena, act->results()[0], stmt->source_loc());
|
|
return UnwindFunctionCall{ret_val};
|
|
}
|
|
case Statement::Kind::Sequence: {
|
|
// { { (s1,s2) :: C, E, F} :: S, H}
|
|
// -> { { s1 :: s2 :: C, E, F} :: S, H}
|
|
const auto& seq = cast<Sequence>(*stmt);
|
|
if (act->pos() == 0) {
|
|
return Spawn{arena->New<StatementAction>(seq.Stmt())};
|
|
} else {
|
|
if (seq.Next()) {
|
|
return Delegate{
|
|
arena->New<StatementAction>(*cast<Sequence>(*stmt).Next())};
|
|
} else {
|
|
return Done{};
|
|
}
|
|
}
|
|
}
|
|
case Statement::Kind::Continuation: {
|
|
CHECK(act->pos() == 0);
|
|
// Create a continuation object by creating a frame similar the
|
|
// way one is created in a function call.
|
|
auto scopes = Stack<Nonnull<Scope*>>(arena->New<Scope>(CurrentEnv()));
|
|
Stack<Nonnull<Action*>> todo;
|
|
todo.Push(arena->New<StatementAction>(
|
|
arena->New<Return>(arena, stmt->source_loc())));
|
|
todo.Push(arena->New<StatementAction>(cast<Continuation>(*stmt).Body()));
|
|
auto continuation_stack = arena->New<std::vector<Nonnull<Frame*>>>();
|
|
auto continuation_frame =
|
|
arena->New<Frame>("__continuation", scopes, todo);
|
|
continuation_stack->push_back(continuation_frame);
|
|
Address continuation_address =
|
|
heap.AllocateValue(arena->New<ContinuationValue>(continuation_stack));
|
|
// Store the continuation's address in the frame.
|
|
continuation_frame->continuation = continuation_address;
|
|
// Bind the continuation object to the continuation variable
|
|
frame->scopes.Top()->values.Set(
|
|
cast<Continuation>(*stmt).ContinuationVariable(),
|
|
continuation_address);
|
|
// Pop the continuation statement.
|
|
frame->todo.Pop();
|
|
return ManualTransition{};
|
|
}
|
|
case Statement::Kind::Run:
|
|
if (act->pos() == 0) {
|
|
// Evaluate the argument of the run statement.
|
|
return Spawn{arena->New<ExpressionAction>(cast<Run>(*stmt).Argument())};
|
|
} else {
|
|
frame->todo.Pop(1);
|
|
// Push an expression statement action to ignore the result
|
|
// value from the continuation.
|
|
auto ignore_result =
|
|
arena->New<StatementAction>(arena->New<ExpressionStatement>(
|
|
stmt->source_loc(),
|
|
arena->New<TupleLiteral>(stmt->source_loc())));
|
|
frame->todo.Push(ignore_result);
|
|
// Push the continuation onto the current stack.
|
|
std::vector<Nonnull<Frame*>>& continuation_vector =
|
|
*cast<ContinuationValue>(*act->results()[0]).Stack();
|
|
while (!continuation_vector.empty()) {
|
|
stack.Push(continuation_vector.back());
|
|
continuation_vector.pop_back();
|
|
}
|
|
return ManualTransition{};
|
|
}
|
|
case Statement::Kind::Await:
|
|
CHECK(act->pos() == 0);
|
|
// Pause the current continuation
|
|
frame->todo.Pop();
|
|
std::vector<Nonnull<Frame*>> paused;
|
|
do {
|
|
paused.push_back(stack.Pop());
|
|
} while (paused.back()->continuation == std::nullopt);
|
|
// Update the continuation with the paused stack.
|
|
const auto& continuation = cast<ContinuationValue>(
|
|
*heap.Read(*paused.back()->continuation, stmt->source_loc()));
|
|
CHECK(continuation.Stack()->empty());
|
|
*continuation.Stack() = 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) {
|
|
Nonnull<Frame*> frame = interpreter->stack.Top();
|
|
if (frame->todo.Top()->kind() != Action::Kind::StatementAction) {
|
|
CHECK(done.result);
|
|
frame->todo.Pop();
|
|
if (frame->todo.IsEmpty()) {
|
|
interpreter->program_value = *done.result;
|
|
} else {
|
|
frame->todo.Top()->AddResult(*done.result);
|
|
}
|
|
} else {
|
|
CHECK(!done.result);
|
|
frame->todo.Pop();
|
|
}
|
|
}
|
|
|
|
void operator()(const Spawn& spawn) {
|
|
Nonnull<Frame*> frame = interpreter->stack.Top();
|
|
Nonnull<Action*> action = frame->todo.Top();
|
|
action->set_pos(action->pos() + 1);
|
|
frame->todo.Push(spawn.child);
|
|
}
|
|
|
|
void operator()(const Delegate& delegate) {
|
|
Nonnull<Frame*> frame = interpreter->stack.Top();
|
|
frame->todo.Pop();
|
|
frame->todo.Push(delegate.delegate);
|
|
}
|
|
|
|
void operator()(const RunAgain&) {
|
|
Nonnull<Action*> action = interpreter->stack.Top()->todo.Top();
|
|
action->set_pos(action->pos() + 1);
|
|
}
|
|
|
|
void operator()(const UnwindTo& unwind_to) {
|
|
Nonnull<Frame*> frame = interpreter->stack.Top();
|
|
while (frame->todo.Top() != unwind_to.new_top) {
|
|
if (HasLocalScope(frame->todo.Top())) {
|
|
interpreter->DeallocateScope(frame->scopes.Top());
|
|
frame->scopes.Pop();
|
|
}
|
|
frame->todo.Pop();
|
|
}
|
|
}
|
|
|
|
void operator()(const UnwindFunctionCall& unwind) {
|
|
interpreter->DeallocateLocals(interpreter->stack.Top());
|
|
interpreter->stack.Pop();
|
|
if (interpreter->stack.Top()->todo.IsEmpty()) {
|
|
interpreter->program_value = unwind.return_val;
|
|
} else {
|
|
interpreter->stack.Top()->todo.Top()->AddResult(unwind.return_val);
|
|
}
|
|
}
|
|
|
|
void operator()(const CallFunction& call) {
|
|
interpreter->stack.Top()->todo.Pop();
|
|
std::optional<Env> matches = interpreter->PatternMatch(
|
|
call.function->Param(), call.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
|
|
Env values = interpreter->globals;
|
|
std::vector<std::string> params;
|
|
for (const auto& [name, value] : *matches) {
|
|
values.Set(name, value);
|
|
params.push_back(name);
|
|
}
|
|
auto scopes =
|
|
Stack<Nonnull<Scope*>>(interpreter->arena->New<Scope>(values, params));
|
|
CHECK(call.function->Body()) << "Calling a function that's missing a body";
|
|
auto todo = Stack<Nonnull<Action*>>(
|
|
interpreter->arena->New<StatementAction>(*call.function->Body()));
|
|
auto frame =
|
|
interpreter->arena->New<Frame>(call.function->Name(), scopes, todo);
|
|
interpreter->stack.Push(frame);
|
|
}
|
|
|
|
void operator()(const ManualTransition&) {}
|
|
|
|
private:
|
|
Nonnull<Interpreter*> interpreter;
|
|
};
|
|
|
|
// State transition.
|
|
void Interpreter::Step() {
|
|
Nonnull<Frame*> frame = stack.Top();
|
|
if (frame->todo.IsEmpty()) {
|
|
std::visit(DoTransition(this),
|
|
Transition{UnwindFunctionCall{TupleValue::Empty()}});
|
|
return;
|
|
}
|
|
|
|
Nonnull<Action*> act = frame->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;
|
|
} // switch
|
|
}
|
|
|
|
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(stack.IsEmpty());
|
|
CHECK(program_value == std::nullopt);
|
|
|
|
if (tracing_output) {
|
|
llvm::outs() << "********** initializing globals **********\n";
|
|
}
|
|
InitGlobals(fs);
|
|
|
|
auto todo = Stack<Nonnull<Action*>>(arena->New<ExpressionAction>(call_main));
|
|
auto scopes = Stack<Nonnull<Scope*>>(arena->New<Scope>(globals));
|
|
stack = Stack<Nonnull<Frame*>>(arena->New<Frame>("top", scopes, todo));
|
|
|
|
if (tracing_output) {
|
|
llvm::outs() << "********** calling main function **********\n";
|
|
PrintState(llvm::outs());
|
|
}
|
|
|
|
while (stack.Count() > 1 || !stack.Top()->todo.IsEmpty()) {
|
|
Step();
|
|
if (tracing_output) {
|
|
PrintState(llvm::outs());
|
|
}
|
|
}
|
|
return cast<IntValue>(**program_value).Val();
|
|
}
|
|
|
|
auto Interpreter::InterpExp(Env values, Nonnull<const Expression*> e)
|
|
-> Nonnull<const Value*> {
|
|
CHECK(program_value == std::nullopt);
|
|
auto program_value_guard =
|
|
llvm::make_scope_exit([&] { program_value = std::nullopt; });
|
|
auto todo = Stack<Nonnull<Action*>>(arena->New<ExpressionAction>(e));
|
|
auto scopes = Stack<Nonnull<Scope*>>(arena->New<Scope>(values));
|
|
stack = Stack<Nonnull<Frame*>>(arena->New<Frame>("InterpExp", scopes, todo));
|
|
|
|
while (stack.Count() > 1 || !stack.Top()->todo.IsEmpty()) {
|
|
Step();
|
|
}
|
|
CHECK(program_value != std::nullopt);
|
|
return *program_value;
|
|
}
|
|
|
|
auto Interpreter::InterpPattern(Env values, Nonnull<const Pattern*> p)
|
|
-> Nonnull<const Value*> {
|
|
CHECK(program_value == std::nullopt);
|
|
auto program_value_guard =
|
|
llvm::make_scope_exit([&] { program_value = std::nullopt; });
|
|
auto todo = Stack<Nonnull<Action*>>(arena->New<PatternAction>(p));
|
|
auto scopes = Stack<Nonnull<Scope*>>(arena->New<Scope>(values));
|
|
stack =
|
|
Stack<Nonnull<Frame*>>(arena->New<Frame>("InterpPattern", scopes, todo));
|
|
|
|
while (stack.Count() > 1 || !stack.Top()->todo.IsEmpty()) {
|
|
Step();
|
|
}
|
|
CHECK(program_value != std::nullopt);
|
|
return *program_value;
|
|
}
|
|
|
|
} // namespace Carbon
|