blob: 5e9bbc6332e40a770ac61308ad187f884611e39f [file] [log] [blame]
// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/ast/modules.h"
#include "src/ast/ast-value-factory.h"
#include "src/ast/scopes.h"
#include "src/objects/module-inl.h"
#include "src/objects/objects-inl.h"
#include "src/parsing/pending-compilation-error-handler.h"
namespace v8 {
namespace internal {
bool ModuleDescriptor::AstRawStringComparer::operator()(
const AstRawString* lhs, const AstRawString* rhs) const {
// Fast path for equal pointers: a pointer is not strictly less than itself.
if (lhs == rhs) return false;
// Order by contents (ordering by hash is unstable across runs).
if (lhs->is_one_byte() != rhs->is_one_byte()) {
return lhs->is_one_byte();
}
if (lhs->byte_length() != rhs->byte_length()) {
return lhs->byte_length() < rhs->byte_length();
}
return memcmp(lhs->raw_data(), rhs->raw_data(), lhs->byte_length()) < 0;
}
void ModuleDescriptor::AddImport(const AstRawString* import_name,
const AstRawString* local_name,
const AstRawString* module_request,
const Scanner::Location loc,
const Scanner::Location specifier_loc,
Zone* zone) {
Entry* entry = new (zone) Entry(loc);
entry->local_name = local_name;
entry->import_name = import_name;
entry->module_request = AddModuleRequest(module_request, specifier_loc);
AddRegularImport(entry);
}
void ModuleDescriptor::AddStarImport(const AstRawString* local_name,
const AstRawString* module_request,
const Scanner::Location loc,
const Scanner::Location specifier_loc,
Zone* zone) {
Entry* entry = new (zone) Entry(loc);
entry->local_name = local_name;
entry->module_request = AddModuleRequest(module_request, specifier_loc);
AddNamespaceImport(entry, zone);
}
void ModuleDescriptor::AddEmptyImport(const AstRawString* module_request,
const Scanner::Location specifier_loc) {
AddModuleRequest(module_request, specifier_loc);
}
void ModuleDescriptor::AddExport(
const AstRawString* local_name, const AstRawString* export_name,
Scanner::Location loc, Zone* zone) {
Entry* entry = new (zone) Entry(loc);
entry->export_name = export_name;
entry->local_name = local_name;
AddRegularExport(entry);
}
void ModuleDescriptor::AddExport(const AstRawString* import_name,
const AstRawString* export_name,
const AstRawString* module_request,
const Scanner::Location loc,
const Scanner::Location specifier_loc,
Zone* zone) {
DCHECK_NOT_NULL(import_name);
DCHECK_NOT_NULL(export_name);
Entry* entry = new (zone) Entry(loc);
entry->export_name = export_name;
entry->import_name = import_name;
entry->module_request = AddModuleRequest(module_request, specifier_loc);
AddSpecialExport(entry, zone);
}
void ModuleDescriptor::AddStarExport(const AstRawString* module_request,
const Scanner::Location loc,
const Scanner::Location specifier_loc,
Zone* zone) {
Entry* entry = new (zone) Entry(loc);
entry->module_request = AddModuleRequest(module_request, specifier_loc);
AddSpecialExport(entry, zone);
}
namespace {
Handle<Object> ToStringOrUndefined(Isolate* isolate, const AstRawString* s) {
return (s == nullptr)
? Handle<Object>::cast(isolate->factory()->undefined_value())
: Handle<Object>::cast(s->string());
}
} // namespace
Handle<ModuleInfoEntry> ModuleDescriptor::Entry::Serialize(
Isolate* isolate) const {
CHECK(Smi::IsValid(module_request)); // TODO(neis): Check earlier?
return ModuleInfoEntry::New(
isolate, ToStringOrUndefined(isolate, export_name),
ToStringOrUndefined(isolate, local_name),
ToStringOrUndefined(isolate, import_name), module_request, cell_index,
location.beg_pos, location.end_pos);
}
Handle<FixedArray> ModuleDescriptor::SerializeRegularExports(Isolate* isolate,
Zone* zone) const {
// We serialize regular exports in a way that lets us later iterate over their
// local names and for each local name immediately access all its export
// names. (Regular exports have neither import name nor module request.)
ZoneVector<Handle<Object>> data(
ModuleInfo::kRegularExportLength * regular_exports_.size(), zone);
int index = 0;
for (auto it = regular_exports_.begin(); it != regular_exports_.end();) {
// Find out how many export names this local name has.
auto next = it;
int count = 0;
do {
DCHECK_EQ(it->second->local_name, next->second->local_name);
DCHECK_EQ(it->second->cell_index, next->second->cell_index);
++next;
++count;
} while (next != regular_exports_.end() && next->first == it->first);
Handle<FixedArray> export_names = isolate->factory()->NewFixedArray(count);
data[index + ModuleInfo::kRegularExportLocalNameOffset] =
it->second->local_name->string();
data[index + ModuleInfo::kRegularExportCellIndexOffset] =
handle(Smi::FromInt(it->second->cell_index), isolate);
data[index + ModuleInfo::kRegularExportExportNamesOffset] = export_names;
index += ModuleInfo::kRegularExportLength;
// Collect the export names.
int i = 0;
for (; it != next; ++it) {
export_names->set(i++, *it->second->export_name->string());
}
DCHECK_EQ(i, count);
// Continue with the next distinct key.
DCHECK(it == next);
}
DCHECK_LE(index, static_cast<int>(data.size()));
data.resize(index);
// We cannot create the FixedArray earlier because we only now know the
// precise size.
Handle<FixedArray> result = isolate->factory()->NewFixedArray(index);
for (int i = 0; i < index; ++i) {
result->set(i, *data[i]);
}
return result;
}
void ModuleDescriptor::MakeIndirectExportsExplicit(Zone* zone) {
for (auto it = regular_exports_.begin(); it != regular_exports_.end();) {
Entry* entry = it->second;
DCHECK_NOT_NULL(entry->local_name);
auto import = regular_imports_.find(entry->local_name);
if (import != regular_imports_.end()) {
// Found an indirect export. Patch export entry and move it from regular
// to special.
DCHECK_NULL(entry->import_name);
DCHECK_LT(entry->module_request, 0);
DCHECK_NOT_NULL(import->second->import_name);
DCHECK_LE(0, import->second->module_request);
DCHECK_LT(import->second->module_request,
static_cast<int>(module_requests_.size()));
entry->import_name = import->second->import_name;
entry->module_request = import->second->module_request;
// Hack: When the indirect export cannot be resolved, we want the error
// message to point at the import statement, not at the export statement.
// Therefore we overwrite [entry]'s location here. Note that Validate()
// has already checked for duplicate exports, so it's guaranteed that we
// won't need to report any error pointing at the (now lost) export
// location.
entry->location = import->second->location;
entry->local_name = nullptr;
AddSpecialExport(entry, zone);
it = regular_exports_.erase(it);
} else {
it++;
}
}
}
ModuleDescriptor::CellIndexKind ModuleDescriptor::GetCellIndexKind(
int cell_index) {
if (cell_index > 0) return kExport;
if (cell_index < 0) return kImport;
return kInvalid;
}
void ModuleDescriptor::AssignCellIndices() {
int export_index = 1;
for (auto it = regular_exports_.begin(); it != regular_exports_.end();) {
auto current_key = it->first;
// This local name may be exported under multiple export names. Assign the
// same index to each such entry.
do {
Entry* entry = it->second;
DCHECK_NOT_NULL(entry->local_name);
DCHECK_NULL(entry->import_name);
DCHECK_LT(entry->module_request, 0);
DCHECK_EQ(entry->cell_index, 0);
entry->cell_index = export_index;
it++;
} while (it != regular_exports_.end() && it->first == current_key);
export_index++;
}
int import_index = -1;
for (const auto& elem : regular_imports_) {
Entry* entry = elem.second;
DCHECK_NOT_NULL(entry->local_name);
DCHECK_NOT_NULL(entry->import_name);
DCHECK_LE(0, entry->module_request);
DCHECK_EQ(entry->cell_index, 0);
entry->cell_index = import_index;
import_index--;
}
}
namespace {
const ModuleDescriptor::Entry* BetterDuplicate(
const ModuleDescriptor::Entry* candidate,
ZoneMap<const AstRawString*, const ModuleDescriptor::Entry*>& export_names,
const ModuleDescriptor::Entry* current_duplicate) {
DCHECK_NOT_NULL(candidate->export_name);
DCHECK(candidate->location.IsValid());
auto insert_result =
export_names.insert(std::make_pair(candidate->export_name, candidate));
if (insert_result.second) return current_duplicate;
if (current_duplicate == nullptr) {
current_duplicate = insert_result.first->second;
}
return (candidate->location.beg_pos > current_duplicate->location.beg_pos)
? candidate
: current_duplicate;
}
} // namespace
const ModuleDescriptor::Entry* ModuleDescriptor::FindDuplicateExport(
Zone* zone) const {
const ModuleDescriptor::Entry* duplicate = nullptr;
ZoneMap<const AstRawString*, const ModuleDescriptor::Entry*> export_names(
zone);
for (const auto& elem : regular_exports_) {
duplicate = BetterDuplicate(elem.second, export_names, duplicate);
}
for (auto entry : special_exports_) {
if (entry->export_name == nullptr) continue; // Star export.
duplicate = BetterDuplicate(entry, export_names, duplicate);
}
return duplicate;
}
bool ModuleDescriptor::Validate(ModuleScope* module_scope,
PendingCompilationErrorHandler* error_handler,
Zone* zone) {
DCHECK_EQ(this, module_scope->module());
DCHECK_NOT_NULL(error_handler);
// Report error iff there are duplicate exports.
{
const Entry* entry = FindDuplicateExport(zone);
if (entry != nullptr) {
error_handler->ReportMessageAt(
entry->location.beg_pos, entry->location.end_pos,
MessageTemplate::kDuplicateExport, entry->export_name);
return false;
}
}
// Report error iff there are exports of non-existent local names.
for (const auto& elem : regular_exports_) {
const Entry* entry = elem.second;
DCHECK_NOT_NULL(entry->local_name);
if (module_scope->LookupLocal(entry->local_name) == nullptr) {
error_handler->ReportMessageAt(
entry->location.beg_pos, entry->location.end_pos,
MessageTemplate::kModuleExportUndefined, entry->local_name);
return false;
}
}
MakeIndirectExportsExplicit(zone);
AssignCellIndices();
return true;
}
} // namespace internal
} // namespace v8