зеркало из https://github.com/mozilla/gecko-dev.git
137 строки
4.9 KiB
C++
137 строки
4.9 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* 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/. */
|
|
|
|
/*
|
|
* Structures and functions for transcoding compiled scripts and functions to
|
|
* and from memory.
|
|
*/
|
|
|
|
#ifndef js_Transcoding_h
|
|
#define js_Transcoding_h
|
|
|
|
#include "mozilla/Range.h" // mozilla::Range
|
|
#include "mozilla/Vector.h" // mozilla::Vector
|
|
|
|
#include <stddef.h> // size_t
|
|
#include <stdint.h> // uint8_t, uint32_t
|
|
|
|
#include "js/TypeDecls.h"
|
|
|
|
namespace JS {
|
|
|
|
class JS_PUBLIC_API ReadOnlyCompileOptions;
|
|
|
|
using TranscodeBuffer = mozilla::Vector<uint8_t>;
|
|
using TranscodeRange = mozilla::Range<const uint8_t>;
|
|
|
|
struct TranscodeSource final {
|
|
TranscodeSource(const TranscodeRange& range_, const char* file, uint32_t line)
|
|
: range(range_), filename(file), lineno(line) {}
|
|
|
|
const TranscodeRange range;
|
|
const char* filename;
|
|
const uint32_t lineno;
|
|
};
|
|
|
|
enum class TranscodeResult : uint8_t {
|
|
// Successful encoding / decoding.
|
|
Ok = 0,
|
|
|
|
// A warning message, is set to the message out-param.
|
|
Failure = 0x10,
|
|
Failure_BadBuildId = Failure | 0x1,
|
|
Failure_AsmJSNotSupported = Failure | 0x2,
|
|
Failure_BadDecode = Failure | 0x3,
|
|
|
|
// There is a pending exception on the context.
|
|
Throw = 0x20
|
|
};
|
|
|
|
inline bool IsTranscodeFailureResult(const TranscodeResult result) {
|
|
uint8_t raw_result = static_cast<uint8_t>(result);
|
|
uint8_t raw_failure = static_cast<uint8_t>(TranscodeResult::Failure);
|
|
TranscodeResult masked =
|
|
static_cast<TranscodeResult>(raw_result & raw_failure);
|
|
return masked == TranscodeResult::Failure;
|
|
}
|
|
|
|
static constexpr size_t BytecodeOffsetAlignment = 4;
|
|
static_assert(BytecodeOffsetAlignment <= alignof(std::max_align_t),
|
|
"Alignment condition requires a custom allocator.");
|
|
|
|
// Align the bytecode offset for transcoding for the requirement.
|
|
inline size_t AlignTranscodingBytecodeOffset(size_t offset) {
|
|
size_t extra = offset % BytecodeOffsetAlignment;
|
|
if (extra == 0) {
|
|
return offset;
|
|
}
|
|
size_t padding = BytecodeOffsetAlignment - extra;
|
|
return offset + padding;
|
|
}
|
|
|
|
inline bool IsTranscodingBytecodeOffsetAligned(size_t offset) {
|
|
return offset % BytecodeOffsetAlignment == 0;
|
|
}
|
|
|
|
inline bool IsTranscodingBytecodeAligned(const void* offset) {
|
|
return IsTranscodingBytecodeOffsetAligned(size_t(offset));
|
|
}
|
|
|
|
// Finish incremental encoding started by JS::StartIncrementalEncoding.
|
|
//
|
|
// * Regular script case
|
|
// the |script| argument must be the top-level script returned from
|
|
// |JS::InstantiateGlobalStencil| with the same stencil
|
|
//
|
|
// * Module script case
|
|
// the |script| argument must be the script returned by
|
|
// |JS::GetModuleScript| called on the module returned by
|
|
// |JS::InstantiateModuleStencil| with the same stencil
|
|
//
|
|
// NOTE: |JS::GetModuleScript| doesn't work after evaluating the
|
|
// module script. For the case, use Handle<JSObject*> variant of
|
|
// this function below.
|
|
//
|
|
// The |buffer| argument of |FinishIncrementalEncoding| is used for appending
|
|
// the encoded bytecode into the buffer. If any of these functions failed, the
|
|
// content of |buffer| would be undefined.
|
|
//
|
|
// |buffer| contains encoded CompilationStencil.
|
|
//
|
|
// If the `buffer` isn't empty, the start of the `buffer` should meet
|
|
// IsTranscodingBytecodeAligned, and the length should meet
|
|
// IsTranscodingBytecodeOffsetAligned.
|
|
//
|
|
// NOTE: As long as IsTranscodingBytecodeOffsetAligned is met, that means
|
|
// there's JS::BytecodeOffsetAlignment+extra bytes in the buffer,
|
|
// IsTranscodingBytecodeAligned should be guaranteed to meet by
|
|
// malloc, used by MallocAllocPolicy in mozilla::Vector.
|
|
extern JS_PUBLIC_API bool FinishIncrementalEncoding(JSContext* cx,
|
|
Handle<JSScript*> script,
|
|
TranscodeBuffer& buffer);
|
|
|
|
// Similar to |JS::FinishIncrementalEncoding|, but receives module obect.
|
|
//
|
|
// The |module| argument must be the module returned by
|
|
// |JS::InstantiateModuleStencil| with the same stencil that's passed to
|
|
// |JS::StartIncrementalEncoding|.
|
|
extern JS_PUBLIC_API bool FinishIncrementalEncoding(JSContext* cx,
|
|
Handle<JSObject*> module,
|
|
TranscodeBuffer& buffer);
|
|
|
|
// Abort incremental encoding started by JS::StartIncrementalEncoding.
|
|
extern JS_PUBLIC_API void AbortIncrementalEncoding(Handle<JSScript*> script);
|
|
extern JS_PUBLIC_API void AbortIncrementalEncoding(Handle<JSObject*> module);
|
|
|
|
// Check if the compile options and script's flag matches.
|
|
//
|
|
// JS::DecodeScript* and JS::DecodeOffThreadScript internally check this.
|
|
extern JS_PUBLIC_API bool CheckCompileOptionsMatch(
|
|
const ReadOnlyCompileOptions& options, JSScript* script);
|
|
|
|
} // namespace JS
|
|
|
|
#endif /* js_Transcoding_h */
|