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/* -*- 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 jit_JitContext_h
#define jit_JitContext_h
#include "mozilla/Assertions.h"
#include "mozilla/Result.h"
#include <stdint.h>
#include "jstypes.h"
struct JS_PUBLIC_API JSContext;
namespace js {
namespace jit {
class CompileRealm;
class CompileRuntime;
class TempAllocator;
enum MethodStatus {
Method_Error,
Method_CantCompile,
Method_Skipped,
Method_Compiled
};
// Use only even, non-zero values for errors, to allow using the UnusedZero and
// HasFreeLSB optimizations for mozilla::Result (see specializations of
// UnusedZero/HasFreeLSB below).
enum class AbortReason : uint8_t {
NoAbort,
Alloc = 2,
Disable = 4,
Error = 6,
};
} // namespace jit
} // namespace js
namespace mozilla::detail {
template <>
struct UnusedZero<js::jit::AbortReason> : UnusedZeroEnum<js::jit::AbortReason> {
};
template <>
struct HasFreeLSB<js::jit::AbortReason> {
static const bool value = true;
};
} // namespace mozilla::detail
namespace js {
namespace jit {
template <typename V>
using AbortReasonOr = mozilla::Result<V, AbortReason>;
using mozilla::Err;
using mozilla::Ok;
static_assert(sizeof(AbortReasonOr<Ok>) <= sizeof(uintptr_t),
"Unexpected size of AbortReasonOr<Ok>");
static_assert(mozilla::detail::SelectResultImpl<bool, AbortReason>::value ==
mozilla::detail::PackingStrategy::NullIsOk);
static_assert(sizeof(AbortReasonOr<bool>) <= sizeof(uintptr_t),
"Unexpected size of AbortReasonOr<bool>");
static_assert(sizeof(AbortReasonOr<uint16_t*>) == sizeof(uintptr_t),
"Unexpected size of AbortReasonOr<uint16_t*>");
// A JIT context is needed for parts of the compiler backend such as the
// MacroAssembler. It points to the JSContext (nullptr for off-thread
// compilations or Wasm compilations) and also stores some extra information,
// most of it only used in debug builds.
//
// JIT contexts must not be nested.
class MOZ_RAII JitContext {
#ifdef DEBUG
// Whether this thread is actively Ion compiling (does not include Wasm or
// WarpOracle).
bool inIonBackend_ = false;
bool isCompilingWasm_ = false;
bool oom_ = false;
#endif
public:
// Running context when compiling on the main thread. Not available during
// off-thread compilation.
JSContext* cx = nullptr;
// Wrapper with information about the current runtime. nullptr for Wasm
// compilations.
CompileRuntime* runtime = nullptr;
// Constructor for compilations happening on the main thread.
explicit JitContext(JSContext* cx);
// Constructor for off-thread Ion compilations.
explicit JitContext(CompileRuntime* rt);
// Constructor for Wasm compilation.
JitContext();
~JitContext();
#ifdef DEBUG
bool isCompilingWasm() { return isCompilingWasm_; }
bool setIsCompilingWasm(bool flag) {
bool oldFlag = isCompilingWasm_;
isCompilingWasm_ = flag;
return oldFlag;
}
bool hasOOM() { return oom_; }
void setOOM() { oom_ = true; }
bool inIonBackend() const { return inIonBackend_; }
void enterIonBackend() {
MOZ_ASSERT(!inIonBackend_);
inIonBackend_ = true;
}
void leaveIonBackend() {
MOZ_ASSERT(inIonBackend_);
inIonBackend_ = false;
}
#endif
};
// Process-wide initialization and shutdown of JIT data structures.
[[nodiscard]] bool InitializeJit();
void ShutdownJit();
// Get and set the current JIT context.
JitContext* GetJitContext();
JitContext* MaybeGetJitContext();
void SetJitContext(JitContext* ctx);
enum JitExecStatus {
// The method call had to be aborted due to a stack limit check. This
// error indicates that Ion never attempted to clean up frames.
JitExec_Aborted,
// The method call resulted in an error, and IonMonkey has cleaned up
// frames.
JitExec_Error,
// The method call succeeded and returned a value.
JitExec_Ok
};
static inline bool IsErrorStatus(JitExecStatus status) {
return status == JitExec_Error || status == JitExec_Aborted;
}
bool JitSupportsWasmSimd();
bool JitSupportsAtomics();
} // namespace jit
} // namespace js
#endif /* jit_JitContext_h */
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