77 строки
1.8 KiB
C++
77 строки
1.8 KiB
C++
/*
|
|
* Copyright (c) Meta Platforms, Inc. and affiliates.
|
|
*
|
|
* This source code is licensed under the MIT license found in the
|
|
* LICENSE file in the root directory of this source tree.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <folly/Portability.h>
|
|
#include <cstdint>
|
|
#include <cstring>
|
|
|
|
#ifndef RN_EXPORT
|
|
#define RN_EXPORT __attribute__((visibility("default")))
|
|
#endif
|
|
|
|
namespace facebook {
|
|
namespace react {
|
|
|
|
/*
|
|
* Scripts given to the JS Executors to run could be in any of the following
|
|
* formats. They are tagged so the executor knows how to run them.
|
|
* Hermes bytecode bundles (as encoded by hermesc, not metro) are not treated
|
|
* in a special way, they will be identified as ScriptTag::String.
|
|
*/
|
|
enum struct ScriptTag {
|
|
String = 0,
|
|
RAMBundle,
|
|
MetroHBCBundle,
|
|
};
|
|
|
|
/**
|
|
* RAM bundles and BC bundles begin with headers. For RAM bundles this is
|
|
* 4 bytes, for BC bundles this is 12 bytes. This structure holds the first 12
|
|
* bytes from a bundle in a way that gives access to that information.
|
|
*/
|
|
FOLLY_PACK_PUSH
|
|
|
|
struct FOLLY_PACK_ATTR Magic32 {
|
|
uint32_t value;
|
|
uint32_t reserved_;
|
|
};
|
|
|
|
struct FOLLY_PACK_ATTR BundleHeader {
|
|
BundleHeader() {
|
|
std::memset(this, 0, sizeof(BundleHeader));
|
|
}
|
|
|
|
union {
|
|
Magic32 magic32;
|
|
uint64_t magic64;
|
|
};
|
|
uint32_t version;
|
|
};
|
|
FOLLY_PACK_POP
|
|
|
|
/**
|
|
* Takes the first 8 bytes of a bundle, and returns a tag describing the
|
|
* bundle's format.
|
|
*/
|
|
RN_EXPORT ScriptTag parseTypeFromHeader(const BundleHeader &header);
|
|
|
|
/**
|
|
* Convert an `ScriptTag` enum into a string, useful for emitting in errors
|
|
* and diagnostic messages.
|
|
*/
|
|
RN_EXPORT const char *stringForScriptTag(const ScriptTag &tag);
|
|
|
|
/**
|
|
* Check whether a given bundle is hermesc-generated bytecode
|
|
*/
|
|
RN_EXPORT bool isHermesBytecodeBundle(const BundleHeader &header);
|
|
|
|
} // namespace react
|
|
} // namespace facebook
|