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// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_WASM_CODE_SPECIALIZATION_H_
#define V8_WASM_CODE_SPECIALIZATION_H_
#include "src/assembler.h"
#include "src/identity-map.h"
#include "src/wasm/wasm-objects.h"
namespace v8 {
namespace internal {
namespace wasm {
// Helper class to specialize wasm code for a specific instance, or to update
// code when memory / globals / tables change.
// This class in unhandlified, and contains a DisallowHeapAllocation field to
// ensure that no allocations happen while it is alive.
//
// Set up all relocations / patching that should be performed by the Relocate* /
// Patch* methods, then apply all changes in one step using the Apply* methods.
class CodeSpecialization {
public:
CodeSpecialization(Isolate*, Zone*);
~CodeSpecialization();
// Update memory references.
void RelocateMemoryReferences(Address old_start, uint32_t old_size,
Address new_start, uint32_t new_size);
// Update references to global variables.
void RelocateGlobals(Address old_start, Address new_start);
// Update function table size.
// TODO(wasm): Prepare this for more than one indirect function table.
void PatchTableSize(uint32_t old_size, uint32_t new_size);
// Update all direct call sites based on the code table in the given instance.
void RelocateDirectCalls(Handle<WasmInstanceObject> instance);
// Relocate an arbitrary object (e.g. function table).
void RelocateObject(Handle<Object> old_obj, Handle<Object> new_obj);
// Apply all relocations and patching to all code in the instance (wasm code
// and exported functions).
bool ApplyToWholeInstance(WasmInstanceObject*,
ICacheFlushMode = FLUSH_ICACHE_IF_NEEDED);
// Apply all relocations and patching to one wasm code object.
bool ApplyToWasmCode(Code*, ICacheFlushMode = FLUSH_ICACHE_IF_NEEDED);
private:
Address old_mem_start = 0;
uint32_t old_mem_size = 0;
Address new_mem_start = 0;
uint32_t new_mem_size = 0;
Address old_globals_start = 0;
Address new_globals_start = 0;
uint32_t old_function_table_size = 0;
uint32_t new_function_table_size = 0;
Handle<WasmInstanceObject> relocate_direct_calls_instance;
bool has_objects_to_relocate = false;
IdentityMap<Handle<Object>, ZoneAllocationPolicy> objects_to_relocate;
};
} // namespace wasm
} // namespace internal
} // namespace v8
#endif // V8_WASM_CODE_SPECIALIZATION_H_
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