1 files changed, 195 insertions, 0 deletions
diff --git a/js/src/frontend/BytecodeSection.cpp b/js/src/frontend/BytecodeSection.cpp
new file mode 100644
index 0000000000..95ba28566d
--- /dev/null
+++ b/js/src/frontend/BytecodeSection.cpp
@@ -0,0 +1,195 @@
+/* -*- 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 "frontend/AbstractScopePtr.h"    // ScopeIndex
+#include "frontend/CompilationStencil.h"  // CompilationStencil
+#include "frontend/FrontendContext.h"     // FrontendContext
+#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.
+    return AbstractScopePtr::compilationEnclosingScope(compilationState);
+  }
+  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());
+}
+
+TaggedParserAtomIndex GCThingList::getAtom(size_t index) const {
+  const TaggedScriptThingIndex& elem = vector[index];
+  return elem.toAtom();
+}
+
+bool js::frontend::EmitScriptThingsVector(
+    JSContext* cx, const CompilationAtomCache& atomCache,
+    const CompilationStencil& 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());
+
+  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: {
+        JSString* str = atomCache.getExistingStringAt(cx, thing.toAtom());
+        MOZ_ASSERT(str);
+        output[i] = JS::GCCellPtr(str);
+        break;
+      }
+      case TaggedScriptThingIndex::Kind::Null:
+        output[i] = JS::GCCellPtr(nullptr);
+        break;
+      case TaggedScriptThingIndex::Kind::BigInt: {
+        const 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: {
+        const ObjLiteralStencil& data =
+            stencil.objLiteralData[thing.toObjLiteral()];
+        JS::GCCellPtr ptr = data.create(cx, atomCache);
+        if (!ptr) {
+          return false;
+        }
+        output[i] = ptr;
+        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.getScope(thing.toScope()));
+        break;
+      case TaggedScriptThingIndex::Kind::Function:
+        output[i] = JS::GCCellPtr(gcOutput.getFunction(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;
+}
+
+BytecodeSection::BytecodeSection(FrontendContext* fc, uint32_t lineNum,
+                                 uint32_t column)
+    : code_(fc),
+      notes_(fc),
+      lastNoteOffset_(0),
+      tryNoteList_(fc),
+      scopeNoteList_(fc),
+      resumeOffsetList_(fc),
+      currentLine_(lineNum),
+      lastColumn_(column) {}
+
+void BytecodeSection::updateDepth(JSOp op, BytecodeOffset target) {
+  jsbytecode* pc = code(target);
+
+  int nuses = StackUses(op, pc);
+  int ndefs = StackDefs(op);
+
+  stackDepth_ -= nuses;
+  MOZ_ASSERT(stackDepth_ >= 0);
+  stackDepth_ += ndefs;
+
+  if (uint32_t(stackDepth_) > maxStackDepth_) {
+    maxStackDepth_ = stackDepth_;
+  }
+}
+
+PerScriptData::PerScriptData(FrontendContext* fc,
+                             frontend::CompilationState& compilationState)
+    : gcThingList_(fc, compilationState),
+      atomIndices_(fc->nameCollectionPool()) {}
+
+bool PerScriptData::init(FrontendContext* fc) {
+  return atomIndices_.acquire(fc);
+}