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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "frontend/BytecodeSection.h"
#include "mozilla/Assertions.h" // MOZ_ASSERT
#include "mozilla/ReverseIterator.h" // mozilla::Reversed
#include "frontend/AbstractScopePtr.h" // ScopeIndex
#include "frontend/CompilationInfo.h"
#include "frontend/SharedContext.h" // FunctionBox
#include "vm/BytecodeUtil.h" // INDEX_LIMIT, StackUses, StackDefs
#include "vm/GlobalObject.h"
#include "vm/JSContext.h" // JSContext
#include "vm/RegExpObject.h" // RegexpObject
#include "vm/Scope.h" // GlobalScope
using namespace js;
using namespace js::frontend;
bool GCThingList::append(FunctionBox* funbox, GCThingIndex* index) {
// Append the function to the vector and return the index in *index.
*index = GCThingIndex(vector.length());
if (!vector.emplaceBack(funbox->index())) {
return false;
}
return true;
}
AbstractScopePtr GCThingList::getScope(size_t index) const {
const TaggedScriptThingIndex& elem = vector[index];
if (elem.isEmptyGlobalScope()) {
// The empty enclosing scope should be stored by
// CompilationInput::initForSelfHostingGlobal.
MOZ_ASSERT(stencil.input.enclosingScope);
MOZ_ASSERT(!stencil.input.enclosingScope->as<GlobalScope>().hasBindings());
return AbstractScopePtr(stencil.input.enclosingScope);
}
return AbstractScopePtr(compilationState, elem.toScope());
}
mozilla::Maybe<ScopeIndex> GCThingList::getScopeIndex(size_t index) const {
const TaggedScriptThingIndex& elem = vector[index];
if (elem.isEmptyGlobalScope()) {
return mozilla::Nothing();
}
return mozilla::Some(vector[index].toScope());
}
bool js::frontend::EmitScriptThingsVector(
JSContext* cx, CompilationInput& input, BaseCompilationStencil& stencil,
CompilationGCOutput& gcOutput,
mozilla::Span<const TaggedScriptThingIndex> things,
mozilla::Span<JS::GCCellPtr> output) {
MOZ_ASSERT(things.size() <= INDEX_LIMIT);
MOZ_ASSERT(things.size() == output.size());
auto& atomCache = input.atomCache;
for (uint32_t i = 0; i < things.size(); i++) {
const auto& thing = things[i];
switch (thing.tag()) {
case TaggedScriptThingIndex::Kind::ParserAtomIndex:
case TaggedScriptThingIndex::Kind::WellKnown: {
JSAtom* atom = atomCache.getExistingAtomAt(cx, thing.toAtom());
MOZ_ASSERT(atom);
output[i] = JS::GCCellPtr(atom);
break;
}
case TaggedScriptThingIndex::Kind::Null:
output[i] = JS::GCCellPtr(nullptr);
break;
case TaggedScriptThingIndex::Kind::BigInt: {
BigIntStencil& data = stencil.bigIntData[thing.toBigInt()];
BigInt* bi = data.createBigInt(cx);
if (!bi) {
return false;
}
output[i] = JS::GCCellPtr(bi);
break;
}
case TaggedScriptThingIndex::Kind::ObjLiteral: {
ObjLiteralStencil& data = stencil.objLiteralData[thing.toObjLiteral()];
JSObject* obj = data.create(cx, atomCache);
if (!obj) {
return false;
}
output[i] = JS::GCCellPtr(obj);
break;
}
case TaggedScriptThingIndex::Kind::RegExp: {
RegExpStencil& data = stencil.regExpData[thing.toRegExp()];
RegExpObject* regexp = data.createRegExp(cx, atomCache);
if (!regexp) {
return false;
}
output[i] = JS::GCCellPtr(regexp);
break;
}
case TaggedScriptThingIndex::Kind::Scope:
output[i] = JS::GCCellPtr(gcOutput.scopes[thing.toScope()]);
break;
case TaggedScriptThingIndex::Kind::Function:
output[i] = JS::GCCellPtr(gcOutput.functions[thing.toFunction()]);
break;
case TaggedScriptThingIndex::Kind::EmptyGlobalScope: {
Scope* scope = &cx->global()->emptyGlobalScope();
output[i] = JS::GCCellPtr(scope);
break;
}
}
}
return true;
}
bool CGTryNoteList::append(TryNoteKind kind, uint32_t stackDepth,
BytecodeOffset start, BytecodeOffset end) {
MOZ_ASSERT(start <= end);
// Offsets are given relative to sections, but we only expect main-section
// to have TryNotes. In finish() we will fixup base offset.
TryNote note(uint32_t(kind), stackDepth, start.toUint32(),
(end - start).toUint32());
return list.append(note);
}
bool CGScopeNoteList::append(GCThingIndex scopeIndex, BytecodeOffset offset,
uint32_t parent) {
ScopeNote note;
note.index = scopeIndex;
note.start = offset.toUint32();
note.length = 0;
note.parent = parent;
return list.append(note);
}
void CGScopeNoteList::recordEnd(uint32_t index, BytecodeOffset offset) {
recordEndImpl(index, offset.toUint32());
}
void CGScopeNoteList::recordEndFunctionBodyVar(uint32_t index) {
recordEndImpl(index, UINT32_MAX);
}
void CGScopeNoteList::recordEndImpl(uint32_t index, uint32_t offset) {
MOZ_ASSERT(index < length());
MOZ_ASSERT(list[index].length == 0);
MOZ_ASSERT(offset >= list[index].start);
list[index].length = offset - list[index].start;
}
JSObject* ObjLiteralStencil::create(JSContext* cx,
CompilationAtomCache& atomCache) const {
return InterpretObjLiteral(cx, atomCache, code_, flags_);
}
BytecodeSection::BytecodeSection(JSContext* cx, uint32_t lineNum,
uint32_t column)
: code_(cx),
notes_(cx),
lastNoteOffset_(0),
tryNoteList_(cx),
scopeNoteList_(cx),
resumeOffsetList_(cx),
currentLine_(lineNum),
lastColumn_(column) {}
void BytecodeSection::updateDepth(BytecodeOffset target) {
jsbytecode* pc = code(target);
int nuses = StackUses(pc);
int ndefs = StackDefs(pc);
stackDepth_ -= nuses;
MOZ_ASSERT(stackDepth_ >= 0);
stackDepth_ += ndefs;
if (uint32_t(stackDepth_) > maxStackDepth_) {
maxStackDepth_ = stackDepth_;
}
}
PerScriptData::PerScriptData(JSContext* cx,
frontend::CompilationStencil& stencil,
frontend::CompilationState& compilationState)
: gcThingList_(cx, stencil, compilationState),
atomIndices_(cx->frontendCollectionPool()) {}
bool PerScriptData::init(JSContext* cx) { return atomIndices_.acquire(cx); }
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