115 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			115 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C++
		
	
	
	
//===- FaultMaps.cpp ------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/FaultMaps.h"
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#include "llvm/ADT/Twine.h"
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#include "llvm/CodeGen/AsmPrinter.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/MC/MCExpr.h"
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#include "llvm/MC/MCObjectFileInfo.h"
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#include "llvm/MC/MCStreamer.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/ErrorHandling.h"
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using namespace llvm;
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#define DEBUG_TYPE "faultmaps"
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static const int FaultMapVersion = 1;
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const char *FaultMaps::WFMP = "Fault Maps: ";
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FaultMaps::FaultMaps(AsmPrinter &AP) : AP(AP) {}
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void FaultMaps::recordFaultingOp(FaultKind FaultTy,
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                                 const MCSymbol *FaultingLabel,
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                                 const MCSymbol *HandlerLabel) {
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  MCContext &OutContext = AP.OutStreamer->getContext();
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  const MCExpr *FaultingOffset = MCBinaryExpr::createSub(
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      MCSymbolRefExpr::create(FaultingLabel, OutContext),
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      MCSymbolRefExpr::create(AP.CurrentFnSymForSize, OutContext), OutContext);
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  const MCExpr *HandlerOffset = MCBinaryExpr::createSub(
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      MCSymbolRefExpr::create(HandlerLabel, OutContext),
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      MCSymbolRefExpr::create(AP.CurrentFnSymForSize, OutContext), OutContext);
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  FunctionInfos[AP.CurrentFnSym].emplace_back(FaultTy, FaultingOffset,
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                                              HandlerOffset);
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}
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void FaultMaps::serializeToFaultMapSection() {
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  if (FunctionInfos.empty())
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    return;
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  MCContext &OutContext = AP.OutStreamer->getContext();
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  MCStreamer &OS = *AP.OutStreamer;
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  // Create the section.
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  MCSection *FaultMapSection =
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      OutContext.getObjectFileInfo()->getFaultMapSection();
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  OS.SwitchSection(FaultMapSection);
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  // Emit a dummy symbol to force section inclusion.
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  OS.emitLabel(OutContext.getOrCreateSymbol(Twine("__LLVM_FaultMaps")));
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  LLVM_DEBUG(dbgs() << "********** Fault Map Output **********\n");
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  // Header
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  OS.emitIntValue(FaultMapVersion, 1); // Version.
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  OS.emitIntValue(0, 1);               // Reserved.
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  OS.emitInt16(0);                     // Reserved.
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  LLVM_DEBUG(dbgs() << WFMP << "#functions = " << FunctionInfos.size() << "\n");
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  OS.emitInt32(FunctionInfos.size());
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  LLVM_DEBUG(dbgs() << WFMP << "functions:\n");
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  for (const auto &FFI : FunctionInfos)
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    emitFunctionInfo(FFI.first, FFI.second);
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}
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void FaultMaps::emitFunctionInfo(const MCSymbol *FnLabel,
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                                 const FunctionFaultInfos &FFI) {
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  MCStreamer &OS = *AP.OutStreamer;
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  LLVM_DEBUG(dbgs() << WFMP << "  function addr: " << *FnLabel << "\n");
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  OS.emitSymbolValue(FnLabel, 8);
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  LLVM_DEBUG(dbgs() << WFMP << "  #faulting PCs: " << FFI.size() << "\n");
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  OS.emitInt32(FFI.size());
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  OS.emitInt32(0); // Reserved
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  for (auto &Fault : FFI) {
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    LLVM_DEBUG(dbgs() << WFMP << "    fault type: "
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                      << faultTypeToString(Fault.Kind) << "\n");
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    OS.emitInt32(Fault.Kind);
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    LLVM_DEBUG(dbgs() << WFMP << "    faulting PC offset: "
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                      << *Fault.FaultingOffsetExpr << "\n");
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    OS.emitValue(Fault.FaultingOffsetExpr, 4);
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    LLVM_DEBUG(dbgs() << WFMP << "    fault handler PC offset: "
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                      << *Fault.HandlerOffsetExpr << "\n");
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    OS.emitValue(Fault.HandlerOffsetExpr, 4);
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  }
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}
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const char *FaultMaps::faultTypeToString(FaultMaps::FaultKind FT) {
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  switch (FT) {
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  default:
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    llvm_unreachable("unhandled fault type!");
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  case FaultMaps::FaultingLoad:
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    return "FaultingLoad";
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  case FaultMaps::FaultingLoadStore:
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    return "FaultingLoadStore";
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  case FaultMaps::FaultingStore:
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    return "FaultingStore";
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  }
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}
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