llvm-project/llvm/lib/CodeGen/FaultMaps.cpp

115 lines
3.5 KiB
C++

//===---------------------------- FaultMaps.cpp ---------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/FaultMaps.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Support/Debug.h"
using namespace llvm;
#define DEBUG_TYPE "faultmaps"
static const int FaultMapVersion = 1;
const char *FaultMaps::WFMP = "Fault Maps: ";
FaultMaps::FaultMaps(AsmPrinter &AP) : AP(AP) {}
void FaultMaps::recordFaultingOp(FaultKind FaultTy,
const MCSymbol *HandlerLabel) {
MCContext &OutContext = AP.OutStreamer->getContext();
MCSymbol *FaultingLabel = OutContext.createTempSymbol();
AP.OutStreamer->EmitLabel(FaultingLabel);
const MCExpr *FaultingOffset = MCBinaryExpr::createSub(
MCSymbolRefExpr::create(FaultingLabel, OutContext),
MCSymbolRefExpr::create(AP.CurrentFnSymForSize, OutContext), OutContext);
const MCExpr *HandlerOffset = MCBinaryExpr::createSub(
MCSymbolRefExpr::create(HandlerLabel, OutContext),
MCSymbolRefExpr::create(AP.CurrentFnSymForSize, OutContext), OutContext);
FunctionInfos[AP.CurrentFnSym].emplace_back(FaultTy, FaultingOffset,
HandlerOffset);
}
void FaultMaps::serializeToFaultMapSection() {
if (FunctionInfos.empty())
return;
MCContext &OutContext = AP.OutStreamer->getContext();
MCStreamer &OS = *AP.OutStreamer;
// Create the section.
MCSection *FaultMapSection =
OutContext.getObjectFileInfo()->getFaultMapSection();
OS.SwitchSection(FaultMapSection);
// Emit a dummy symbol to force section inclusion.
OS.EmitLabel(OutContext.getOrCreateSymbol(Twine("__LLVM_FaultMaps")));
DEBUG(dbgs() << "********** Fault Map Output **********\n");
// Header
OS.EmitIntValue(FaultMapVersion, 1); // Version.
OS.EmitIntValue(0, 1); // Reserved.
OS.EmitIntValue(0, 2); // Reserved.
DEBUG(dbgs() << WFMP << "#functions = " << FunctionInfos.size() << "\n");
OS.EmitIntValue(FunctionInfos.size(), 4);
DEBUG(dbgs() << WFMP << "functions:\n");
for (const auto &FFI : FunctionInfos)
emitFunctionInfo(FFI.first, FFI.second);
}
void FaultMaps::emitFunctionInfo(const MCSymbol *FnLabel,
const FunctionFaultInfos &FFI) {
MCStreamer &OS = *AP.OutStreamer;
DEBUG(dbgs() << WFMP << " function addr: " << *FnLabel << "\n");
OS.EmitSymbolValue(FnLabel, 8);
DEBUG(dbgs() << WFMP << " #faulting PCs: " << FFI.size() << "\n");
OS.EmitIntValue(FFI.size(), 4);
OS.EmitIntValue(0, 4); // Reserved
for (auto &Fault : FFI) {
DEBUG(dbgs() << WFMP << " fault type: "
<< faultTypeToString(Fault.Kind) << "\n");
OS.EmitIntValue(Fault.Kind, 4);
DEBUG(dbgs() << WFMP << " faulting PC offset: "
<< *Fault.FaultingOffsetExpr << "\n");
OS.EmitValue(Fault.FaultingOffsetExpr, 4);
DEBUG(dbgs() << WFMP << " fault handler PC offset: "
<< *Fault.HandlerOffsetExpr << "\n");
OS.EmitValue(Fault.HandlerOffsetExpr, 4);
}
}
const char *FaultMaps::faultTypeToString(FaultMaps::FaultKind FT) {
switch (FT) {
default:
llvm_unreachable("unhandled fault type!");
case FaultMaps::FaultingLoad:
return "FaultingLoad";
}
}