Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

1 files changed, 217 insertions, 0 deletions

diff --git a/js/src/frontend/StencilXdr.h b/js/src/frontend/StencilXdr.h
new file mode 100644
index 0000000000..a07e7787fa
--- /dev/null
+++ b/js/src/frontend/StencilXdr.h
@@ -0,0 +1,217 @@
+/* -*- 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_StencilXdr_h
+#define frontend_StencilXdr_h
+
+#include "mozilla/RefPtr.h"  // RefPtr
+
+#include "frontend/ParserAtom.h"  // ParserAtom, ParserAtomSpan
+#include "frontend/Stencil.h"  // BitIntStencil, ScopeStencil, BaseParserScopeData
+#include "vm/Xdr.h"            // XDRMode, XDRResult, XDRState
+
+namespace JS {
+
+class DecodeOptions;
+
+}  // namespace JS
+
+namespace js {
+
+class LifoAlloc;
+class ObjLiteralStencil;
+class ScriptSource;
+class SharedImmutableScriptData;
+
+class XDRStencilDecoder;
+class XDRStencilEncoder;
+
+namespace frontend {
+
+struct CompilationStencil;
+struct ExtensibleCompilationStencil;
+struct SharedDataContainer;
+
+// Check that we can copy data to disk and restore it in another instance of
+// the program in a different address space.
+template <typename DataT>
+struct CanCopyDataToDisk {
+  // Check that the object is fully packed, to save disk space.
+#ifdef __cpp_lib_has_unique_object_representations
+  static constexpr bool unique_repr =
+      std::has_unique_object_representations<DataT>();
+#else
+  static constexpr bool unique_repr = true;
+#endif
+
+  // Approximation which assumes that 32bits variant of the class would not
+  // have pointers if the 64bits variant does not have pointer.
+  static constexpr bool no_pointer =
+      alignof(DataT) < alignof(void*) || sizeof(void*) == sizeof(uint32_t);
+
+  static constexpr bool value = unique_repr && no_pointer;
+};
+
+// This is just a namespace class that can be used in friend declarations,
+// so that the statically declared XDR methods within have access to the
+// relevant struct internals.
+class StencilXDR {
+ private:
+  template <XDRMode mode>
+  [[nodiscard]] static XDRResult codeSourceUnretrievableUncompressed(
+      XDRState<mode>* xdr, ScriptSource* ss, uint8_t sourceCharSize,
+      uint32_t uncompressedLength);
+
+  template <typename Unit,
+            template <typename U, SourceRetrievable CanRetrieve> class Data,
+            XDRMode mode>
+  static void codeSourceRetrievable(ScriptSource* ss);
+
+  template <typename Unit, XDRMode mode>
+  [[nodiscard]] static XDRResult codeSourceUncompressedData(
+      XDRState<mode>* const xdr, ScriptSource* const ss);
+
+  template <typename Unit, XDRMode mode>
+  [[nodiscard]] static XDRResult codeSourceCompressedData(
+      XDRState<mode>* const xdr, ScriptSource* const ss);
+
+  template <typename Unit, XDRMode mode>
+  static void codeSourceRetrievableData(ScriptSource* ss);
+
+  template <XDRMode mode>
+  [[nodiscard]] static XDRResult codeSourceData(XDRState<mode>* const xdr,
+                                                ScriptSource* const ss);
+
+ public:
+  template <XDRMode mode>
+  static XDRResult codeSource(XDRState<mode>* xdr,
+                              const JS::DecodeOptions* maybeOptions,
+                              RefPtr<ScriptSource>& source);
+
+  template <XDRMode mode>
+  static XDRResult codeBigInt(XDRState<mode>* xdr, LifoAlloc& alloc,
+                              BigIntStencil& stencil);
+
+  template <XDRMode mode>
+  static XDRResult codeObjLiteral(XDRState<mode>* xdr, LifoAlloc& alloc,
+                                  ObjLiteralStencil& stencil);
+
+  template <XDRMode mode>
+  static XDRResult codeScopeData(XDRState<mode>* xdr, LifoAlloc& alloc,
+                                 ScopeStencil& stencil,
+                                 BaseParserScopeData*& baseScopeData);
+
+  template <XDRMode mode>
+  static XDRResult codeSharedData(XDRState<mode>* xdr,
+                                  RefPtr<SharedImmutableScriptData>& sisd);
+
+  template <XDRMode mode>
+  static XDRResult codeSharedDataContainer(XDRState<mode>* xdr,
+                                           SharedDataContainer& sharedData);
+
+  template <XDRMode mode>
+  static XDRResult codeParserAtom(XDRState<mode>* xdr, LifoAlloc& alloc,
+                                  ParserAtom** atomp);
+
+  template <XDRMode mode>
+  static XDRResult codeParserAtomSpan(XDRState<mode>* xdr, LifoAlloc& alloc,
+                                      ParserAtomSpan& parserAtomData);
+
+  template <XDRMode mode>
+  static XDRResult codeModuleRequest(XDRState<mode>* xdr,
+                                     StencilModuleRequest& stencil);
+
+  template <XDRMode mode>
+  static XDRResult codeModuleRequestVector(
+      XDRState<mode>* xdr, StencilModuleMetadata::RequestVector& vector);
+
+  template <XDRMode mode>
+  static XDRResult codeModuleEntry(XDRState<mode>* xdr,
+                                   StencilModuleEntry& stencil);
+
+  template <XDRMode mode>
+  static XDRResult codeModuleEntryVector(
+      XDRState<mode>* xdr, StencilModuleMetadata::EntryVector& vector);
+
+  template <XDRMode mode>
+  static XDRResult codeModuleMetadata(XDRState<mode>* xdr,
+                                      StencilModuleMetadata& stencil);
+
+  static XDRResult checkCompilationStencil(XDRStencilEncoder* encoder,
+                                           const CompilationStencil& stencil);
+
+  static XDRResult checkCompilationStencil(
+      const ExtensibleCompilationStencil& stencil);
+
+  template <XDRMode mode>
+  static XDRResult codeCompilationStencil(XDRState<mode>* xdr,
+                                          CompilationStencil& stencil);
+};
+
+} /* namespace frontend */
+
+/*
+ * The structure of the Stencil XDR buffer is:
+ *
+ * 1. Version
+ * 2. length of content
+ * 3. checksum of content
+ * 4. content
+ *   a. ScriptSource
+ *   b. CompilationStencil
+ */
+
+/*
+ * The stencil decoder accepts `range` as input.
+ *
+ * The decoded stencils are outputted to the default-initialized
+ * `stencil` parameter of `codeStencil` method.
+ *
+ * The decoded stencils borrow the input `buffer`/`range`, and the consumer
+ * has to keep the buffer alive while the decoded stencils are alive.
+ */
+class XDRStencilDecoder : public XDRState<XDR_DECODE> {
+  using Base = XDRState<XDR_DECODE>;
+
+ public:
+  XDRStencilDecoder(FrontendContext* fc, const JS::TranscodeRange& range)
+      : Base(fc, range) {
+    MOZ_ASSERT(JS::IsTranscodingBytecodeAligned(range.begin().get()));
+  }
+
+  XDRResult codeStencil(const JS::DecodeOptions& options,
+                        frontend::CompilationStencil& stencil);
+
+  const JS::DecodeOptions& options() {
+    MOZ_ASSERT(options_);
+    return *options_;
+  }
+
+ private:
+  const JS::DecodeOptions* options_ = nullptr;
+};
+
+class XDRStencilEncoder : public XDRState<XDR_ENCODE> {
+  using Base = XDRState<XDR_ENCODE>;
+
+ public:
+  XDRStencilEncoder(FrontendContext* fc, JS::TranscodeBuffer& buffer)
+      : Base(fc, buffer, buffer.length()) {
+    // NOTE: If buffer is empty, buffer.begin() doesn't point valid buffer.
+    MOZ_ASSERT_IF(!buffer.empty(),
+                  JS::IsTranscodingBytecodeAligned(buffer.begin()));
+    MOZ_ASSERT(JS::IsTranscodingBytecodeOffsetAligned(buffer.length()));
+  }
+
+  XDRResult codeStencil(const RefPtr<ScriptSource>& source,
+                        const frontend::CompilationStencil& stencil);
+
+  XDRResult codeStencil(const frontend::CompilationStencil& stencil);
+};
+
+} /* namespace js */
+
+#endif /* frontend_StencilXdr_h */