1//===---------------------------- FaultMaps.cpp ---------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "llvm/CodeGen/FaultMaps.h"
11
12#include "llvm/CodeGen/AsmPrinter.h"
13#include "llvm/MC/MCContext.h"
14#include "llvm/MC/MCExpr.h"
15#include "llvm/MC/MCObjectFileInfo.h"
16#include "llvm/MC/MCStreamer.h"
17#include "llvm/Support/Debug.h"
18
19using namespace llvm;
20
21#define DEBUG_TYPE "faultmaps"
22
23static const int FaultMapVersion = 1;
24const char *FaultMaps::WFMP = "Fault Maps: ";
25
26FaultMaps::FaultMaps(AsmPrinter &AP) : AP(AP) {}
27
28void FaultMaps::recordFaultingOp(FaultKind FaultTy,
29                                 const MCSymbol *HandlerLabel) {
30  MCContext &OutContext = AP.OutStreamer->getContext();
31  MCSymbol *FaultingLabel = OutContext.createTempSymbol();
32
33  AP.OutStreamer->EmitLabel(FaultingLabel);
34
35  const MCExpr *FaultingOffset = MCBinaryExpr::createSub(
36      MCSymbolRefExpr::create(FaultingLabel, OutContext),
37      MCSymbolRefExpr::create(AP.CurrentFnSymForSize, OutContext), OutContext);
38
39  const MCExpr *HandlerOffset = MCBinaryExpr::createSub(
40      MCSymbolRefExpr::create(HandlerLabel, OutContext),
41      MCSymbolRefExpr::create(AP.CurrentFnSymForSize, OutContext), OutContext);
42
43  FunctionInfos[AP.CurrentFnSym].emplace_back(FaultTy, FaultingOffset,
44                                              HandlerOffset);
45}
46
47void FaultMaps::serializeToFaultMapSection() {
48  if (FunctionInfos.empty())
49    return;
50
51  MCContext &OutContext = AP.OutStreamer->getContext();
52  MCStreamer &OS = *AP.OutStreamer;
53
54  // Create the section.
55  MCSection *FaultMapSection =
56      OutContext.getObjectFileInfo()->getFaultMapSection();
57  OS.SwitchSection(FaultMapSection);
58
59  // Emit a dummy symbol to force section inclusion.
60  OS.EmitLabel(OutContext.getOrCreateSymbol(Twine("__LLVM_FaultMaps")));
61
62  DEBUG(dbgs() << "********** Fault Map Output **********\n");
63
64  // Header
65  OS.EmitIntValue(FaultMapVersion, 1); // Version.
66  OS.EmitIntValue(0, 1);               // Reserved.
67  OS.EmitIntValue(0, 2);               // Reserved.
68
69  DEBUG(dbgs() << WFMP << "#functions = " << FunctionInfos.size() << "\n");
70  OS.EmitIntValue(FunctionInfos.size(), 4);
71
72  DEBUG(dbgs() << WFMP << "functions:\n");
73
74  for (const auto &FFI : FunctionInfos)
75    emitFunctionInfo(FFI.first, FFI.second);
76}
77
78void FaultMaps::emitFunctionInfo(const MCSymbol *FnLabel,
79                                 const FunctionFaultInfos &FFI) {
80  MCStreamer &OS = *AP.OutStreamer;
81
82  DEBUG(dbgs() << WFMP << "  function addr: " << *FnLabel << "\n");
83  OS.EmitSymbolValue(FnLabel, 8);
84
85  DEBUG(dbgs() << WFMP << "  #faulting PCs: " << FFI.size() << "\n");
86  OS.EmitIntValue(FFI.size(), 4);
87
88  OS.EmitIntValue(0, 4); // Reserved
89
90  for (auto &Fault : FFI) {
91    DEBUG(dbgs() << WFMP << "    fault type: "
92          << faultTypeToString(Fault.Kind) << "\n");
93    OS.EmitIntValue(Fault.Kind, 4);
94
95    DEBUG(dbgs() << WFMP << "    faulting PC offset: "
96          << *Fault.FaultingOffsetExpr << "\n");
97    OS.EmitValue(Fault.FaultingOffsetExpr, 4);
98
99    DEBUG(dbgs() << WFMP << "    fault handler PC offset: "
100          << *Fault.HandlerOffsetExpr << "\n");
101    OS.EmitValue(Fault.HandlerOffsetExpr, 4);
102  }
103}
104
105
106const char *FaultMaps::faultTypeToString(FaultMaps::FaultKind FT) {
107  switch (FT) {
108  default:
109    llvm_unreachable("unhandled fault type!");
110
111  case FaultMaps::FaultingLoad:
112    return "FaultingLoad";
113  }
114}
115
116raw_ostream &llvm::
117operator<<(raw_ostream &OS,
118           const FaultMapParser::FunctionFaultInfoAccessor &FFI) {
119  OS << "Fault kind: "
120     << FaultMaps::faultTypeToString((FaultMaps::FaultKind)FFI.getFaultKind())
121     << ", faulting PC offset: " << FFI.getFaultingPCOffset()
122     << ", handling PC offset: " << FFI.getHandlerPCOffset();
123  return OS;
124}
125
126raw_ostream &llvm::
127operator<<(raw_ostream &OS, const FaultMapParser::FunctionInfoAccessor &FI) {
128  OS << "FunctionAddress: " << format_hex(FI.getFunctionAddr(), 8)
129     << ", NumFaultingPCs: " << FI.getNumFaultingPCs() << "\n";
130  for (unsigned i = 0, e = FI.getNumFaultingPCs(); i != e; ++i)
131    OS << FI.getFunctionFaultInfoAt(i) << "\n";
132  return OS;
133}
134
135raw_ostream &llvm::operator<<(raw_ostream &OS, const FaultMapParser &FMP) {
136  OS << "Version: " << format_hex(FMP.getFaultMapVersion(), 2) << "\n";
137  OS << "NumFunctions: " << FMP.getNumFunctions() << "\n";
138
139  if (FMP.getNumFunctions() == 0)
140    return OS;
141
142  FaultMapParser::FunctionInfoAccessor FI;
143
144  for (unsigned i = 0, e = FMP.getNumFunctions(); i != e; ++i) {
145    FI = (i == 0) ? FMP.getFirstFunctionInfo() : FI.getNextFunctionInfo();
146    OS << FI;
147  }
148
149  return OS;
150}
151