Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 231 insertions, 0 deletions

diff --git a/js/src/frontend/PrivateOpEmitter.h b/js/src/frontend/PrivateOpEmitter.h
new file mode 100644
index 0000000000..558541b05c
--- /dev/null
+++ b/js/src/frontend/PrivateOpEmitter.h
@@ -0,0 +1,231 @@
+/* -*- 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/. */
+
+#ifndef frontend_PrivateOpEmitter_h
+#define frontend_PrivateOpEmitter_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/Maybe.h"
+
+#include <stddef.h>
+
+#include "frontend/NameAnalysisTypes.h"  // NameLocation
+#include "frontend/ParserAtom.h"         // TaggedParserAtomIndex
+
+namespace js {
+namespace frontend {
+
+struct BytecodeEmitter;
+enum class ValueUsage;
+
+// Class for emitting bytecode for operations on private members of objects.
+//
+// Usage is similar to PropOpEmitter, but the name of the private member must
+// be passed to the constructor; prepare*() methods aren't necessary; and
+// `delete obj.#member` and `super.#member` aren't supported because both are
+// SyntaxErrors.
+//
+// Usage: (error checking is omitted for simplicity)
+//
+//   `obj.#member;`
+//     PrivateOpEmitter xoe(this,
+//                          privateName,
+//                          PrivateOpEmitter::Kind::Get);
+//     emit(obj);
+//     xoe.emitReference();
+//     xoe.emitGet();
+//
+//   `obj.#member();`
+//     PrivateOpEmitter xoe(this,
+//                          privateName,
+//                          PrivateOpEmitter::Kind::Call);
+//     emit(obj);
+//     xoe.emitReference();
+//     xoe.emitGet();
+//     emit_call_here();
+//
+//   `new obj.#member();`
+//     The same, but use PrivateOpEmitter::Kind::Get.
+//
+//   `obj.#field++;`
+//     PrivateOpEmitter xoe(this,
+//                          privateName,
+//                          PrivateOpEmitter::Kind::PostIncrement);
+//     emit(obj);
+//     xoe.emitReference();
+//     xoe.emitIncDec();
+//
+//   `obj.#field = value;`
+//     PrivateOpEmitter xoe(this,
+//                          privateName,
+//                          PrivateOpEmitter::Kind::SimpleAssignment);
+//     emit(obj);
+//     xoe.emitReference();
+//     emit(value);
+//     xoe.emitAssignment();
+//
+//   `obj.#field += value;`
+//     PrivateOpEmitter xoe(this,
+//                          privateName,
+//                          PrivateOpEmitter::Kind::CompoundAssignment);
+//     emit(obj);
+//     xoe.emitReference();
+//     emit(JSOp::Dup2);
+//     xoe.emitGet();
+//     emit(value);
+//     emit_add_op_here();
+//     xoe.emitAssignment();
+//
+class MOZ_STACK_CLASS PrivateOpEmitter {
+ public:
+  enum class Kind {
+    Get,
+    Call,
+    Delete,
+    PostIncrement,
+    PreIncrement,
+    PostDecrement,
+    PreDecrement,
+    SimpleAssignment,
+    PropInit,
+    CompoundAssignment,
+    ErgonomicBrandCheck,
+  };
+
+ private:
+  BytecodeEmitter* bce_;
+
+  Kind kind_;
+
+  // Name of the private member, e.g. "#field".
+  TaggedParserAtomIndex name_;
+
+  // Location of the slot containing the private name symbol; or, for a
+  // non-static private method, the slot containing the method.
+  mozilla::Maybe<NameLocation> loc_;
+
+  // For non-static private method accesses, the location of the relevant
+  // `.privateBrand` binding. Otherwise, `Nothing`.
+  mozilla::Maybe<NameLocation> brandLoc_{};
+
+#ifdef DEBUG
+  // The state of this emitter.
+  //
+  //            emitReference
+  // +-------+  skipReference  +-----------+
+  // | Start |---------------->| Reference |
+  // +-------+                 +-----+-----+
+  //                                 |
+  //     +---------------------------+
+  //     |
+  //     |
+  //     | [Get]
+  //     |   emitGet
+  //     | [Call] [Get]                  [CompoundAssignment]
+  //     |   emitGetForCallOrNew +-----+   emitAssignment
+  //     +---------------------->| Get |-------------------+
+  //     |                       +-----+                   |
+  //     | [PostIncrement]                                 |
+  //     | [PreIncrement]                                  |
+  //     | [PostDecrement]                                 |
+  //     | [PreDecrement]                                  |
+  //     |   emitIncDec                                    |
+  //     +------------------------------------------------>+
+  //     |                                                 |
+  //     | [SimpleAssignment]                              |
+  //     | [PropInit]                                      V
+  //     |   emitAssignment                          +------------+
+  //     +------------------------------------------>| Assignment |
+  //                                                 +------------+
+  enum class State {
+    // The initial state.
+    Start,
+
+    // After calling emitReference or skipReference.
+    Reference,
+
+    // After calling emitGet.
+    Get,
+
+    // After calling emitAssignment or emitIncDec.
+    Assignment,
+  };
+  State state_ = State::Start;
+#endif
+
+ public:
+  PrivateOpEmitter(BytecodeEmitter* bce, Kind kind, TaggedParserAtomIndex name);
+
+ private:
+  [[nodiscard]] bool isCall() const { return kind_ == Kind::Call; }
+
+  [[nodiscard]] bool isSimpleAssignment() const {
+    return kind_ == Kind::SimpleAssignment;
+  }
+
+  [[nodiscard]] bool isFieldInit() const { return kind_ == Kind::PropInit; }
+
+  [[nodiscard]] bool isBrandCheck() const {
+    return kind_ == Kind::ErgonomicBrandCheck;
+  }
+
+  [[nodiscard]] bool isCompoundAssignment() const {
+    return kind_ == Kind::CompoundAssignment;
+  }
+
+  [[nodiscard]] bool isIncDec() const {
+    return isPostIncDec() || isPreIncDec();
+  }
+
+  [[nodiscard]] bool isPostIncDec() const {
+    return kind_ == Kind::PostIncrement || kind_ == Kind::PostDecrement;
+  }
+
+  [[nodiscard]] bool isPreIncDec() const {
+    return kind_ == Kind::PreIncrement || kind_ == Kind::PreDecrement;
+  }
+
+  [[nodiscard]] bool isInc() const {
+    return kind_ == Kind::PostIncrement || kind_ == Kind::PreIncrement;
+  }
+
+  [[nodiscard]] bool init();
+
+  // Emit a GetAliasedLexical or similar instruction.
+  [[nodiscard]] bool emitLoad(TaggedParserAtomIndex name,
+                              const NameLocation& loc);
+
+  [[nodiscard]] bool emitLoadPrivateBrand();
+
+ public:
+  // Emit bytecode to check for the presence/absence of a private field/brand.
+  //
+  // Given OBJ KEY on the stack, where KEY is a private name symbol, the
+  // emitted code will throw if OBJ does not have the given KEY.
+  //
+  // If `isFieldInit()`, the check is reversed: the code will throw if OBJ
+  // already has the KEY.
+  //
+  // If `isBrandCheck()`, the check verifies RHS is an object (throwing if not).
+  //
+  // The bytecode leaves OBJ KEY BOOL on the stack. Caller is responsible for
+  // consuming or popping it.
+  [[nodiscard]] bool emitBrandCheck();
+
+  [[nodiscard]] bool emitReference();
+  [[nodiscard]] bool skipReference();
+  [[nodiscard]] bool emitGet();
+  [[nodiscard]] bool emitGetForCallOrNew();
+  [[nodiscard]] bool emitAssignment();
+  [[nodiscard]] bool emitIncDec(ValueUsage valueUsage);
+
+  [[nodiscard]] size_t numReferenceSlots() { return 2; }
+};
+
+} /* namespace frontend */
+} /* namespace js */
+
+#endif /* frontend_PrivateOpEmitter_h */