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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:
*
* Copyright 2021 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "wasm/WasmDebugFrame.h"
#include "vm/EnvironmentObject.h"
#include "wasm/WasmBaselineCompile.h"
#include "wasm/WasmDebug.h"
#include "wasm/WasmInstance.h"
#include "wasm/WasmInstanceData.h"
#include "wasm/WasmStubs.h"
#include "vm/NativeObject-inl.h"
#include "wasm/WasmInstance-inl.h"
using namespace js;
using namespace js::jit;
using namespace js::wasm;
/* static */
DebugFrame* DebugFrame::from(Frame* fp) {
MOZ_ASSERT(GetNearestEffectiveInstance(fp)->code().metadata().debugEnabled);
auto* df =
reinterpret_cast<DebugFrame*>((uint8_t*)fp - DebugFrame::offsetOfFrame());
MOZ_ASSERT(GetNearestEffectiveInstance(fp) == df->instance());
return df;
}
void DebugFrame::alignmentStaticAsserts() {
// VS2017 doesn't consider offsetOfFrame() to be a constexpr, so we have
// to use offsetof directly. These asserts can't be at class-level
// because the type is incomplete.
static_assert(WasmStackAlignment >= Alignment,
"Aligned by ABI before pushing DebugFrame");
#ifndef JS_CODEGEN_NONE
static_assert((offsetof(DebugFrame, frame_) + sizeof(Frame)) % Alignment == 0,
"Aligned after pushing DebugFrame");
#endif
#ifdef JS_CODEGEN_ARM64
// This constraint may or may not be necessary. If you hit this because
// you've changed the frame size then feel free to remove it, but be extra
// aware of possible problems.
static_assert(sizeof(DebugFrame) % 16 == 0, "ARM64 SP alignment");
#endif
}
Instance* DebugFrame::instance() {
return GetNearestEffectiveInstance(&frame_);
}
const Instance* DebugFrame::instance() const {
return GetNearestEffectiveInstance(&frame_);
}
GlobalObject* DebugFrame::global() { return &instance()->object()->global(); }
bool DebugFrame::hasGlobal(const GlobalObject* global) const {
return global == &instance()->objectUnbarriered()->global();
}
JSObject* DebugFrame::environmentChain() {
return &global()->lexicalEnvironment();
}
bool DebugFrame::getLocal(uint32_t localIndex, MutableHandleValue vp) {
ValTypeVector locals;
size_t argsLength;
StackResults stackResults;
if (!instance()->debug().debugGetLocalTypes(funcIndex(), &locals, &argsLength,
&stackResults)) {
return false;
}
ValTypeVector args;
MOZ_ASSERT(argsLength <= locals.length());
if (!args.append(locals.begin(), argsLength)) {
return false;
}
ArgTypeVector abiArgs(args, stackResults);
BaseLocalIter iter(locals, abiArgs, /* debugEnabled = */ true);
while (!iter.done() && iter.index() < localIndex) {
iter++;
}
MOZ_ALWAYS_TRUE(!iter.done());
uint8_t* frame = static_cast<uint8_t*>((void*)this) + offsetOfFrame();
void* dataPtr = frame - iter.frameOffset();
switch (iter.mirType()) {
case jit::MIRType::Int32:
vp.set(Int32Value(*static_cast<int32_t*>(dataPtr)));
break;
case jit::MIRType::Int64:
// Just display as a Number; it's ok if we lose some precision
vp.set(NumberValue((double)*static_cast<int64_t*>(dataPtr)));
break;
case jit::MIRType::Float32:
vp.set(NumberValue(JS::CanonicalizeNaN(*static_cast<float*>(dataPtr))));
break;
case jit::MIRType::Double:
vp.set(NumberValue(JS::CanonicalizeNaN(*static_cast<double*>(dataPtr))));
break;
case jit::MIRType::WasmAnyRef:
vp.set(((AnyRef*)dataPtr)->toJSValue());
break;
#ifdef ENABLE_WASM_SIMD
case jit::MIRType::Simd128:
vp.set(NumberValue(0));
break;
#endif
default:
MOZ_CRASH("local type");
}
return true;
}
bool DebugFrame::updateReturnJSValue(JSContext* cx) {
MutableHandleValue rval =
MutableHandleValue::fromMarkedLocation(&cachedReturnJSValue_);
rval.setUndefined();
flags_.hasCachedReturnJSValue = true;
ResultType resultType = ResultType::Vector(
instance()->metadata().debugFuncType(funcIndex()).results());
Maybe<char*> stackResultsLoc;
if (ABIResultIter::HasStackResults(resultType)) {
stackResultsLoc = Some(static_cast<char*>(stackResultsPointer_));
}
DebugCodegen(DebugChannel::Function,
"wasm-function[%d] updateReturnJSValue [", funcIndex());
bool ok =
ResultsToJSValue(cx, resultType, registerResults_, stackResultsLoc, rval);
DebugCodegen(DebugChannel::Function, "]\n");
return ok;
}
void DebugFrame::discardReturnJSValue() {
MutableHandleValue rval =
MutableHandleValue::fromMarkedLocation(&cachedReturnJSValue_);
rval.setMagic(JS_OPTIMIZED_OUT);
flags_.hasCachedReturnJSValue = true;
}
HandleValue DebugFrame::returnValue() const {
MOZ_ASSERT(flags_.hasCachedReturnJSValue);
return HandleValue::fromMarkedLocation(&cachedReturnJSValue_);
}
void DebugFrame::clearReturnJSValue() {
flags_.hasCachedReturnJSValue = true;
cachedReturnJSValue_.setUndefined();
}
void DebugFrame::observe(JSContext* cx) {
if (!flags_.observing) {
instance()->debug().adjustEnterAndLeaveFrameTrapsState(
cx, instance(), /* enabled = */ true);
flags_.observing = true;
}
}
void DebugFrame::leave(JSContext* cx) {
if (flags_.observing) {
instance()->debug().adjustEnterAndLeaveFrameTrapsState(
cx, instance(), /* enabled = */ false);
flags_.observing = false;
}
}