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
19 using namespace llvm;
20
21 #define DEBUG_TYPE "faultmaps"
22
23 static const int FaultMapVersion = 1;
24 const char *FaultMaps::WFMP = "Fault Maps: ";
25
FaultMaps(AsmPrinter & AP)26 FaultMaps::FaultMaps(AsmPrinter &AP) : AP(AP) {}
27
recordFaultingOp(FaultKind FaultTy,const MCSymbol * HandlerLabel)28 void 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
serializeToFaultMapSection()47 void 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
emitFunctionInfo(const MCSymbol * FnLabel,const FunctionFaultInfos & FFI)78 void 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
faultTypeToString(FaultMaps::FaultKind FT)106 const 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
116 raw_ostream &llvm::
operator <<(raw_ostream & OS,const FaultMapParser::FunctionFaultInfoAccessor & FFI)117 operator<<(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
126 raw_ostream &llvm::
operator <<(raw_ostream & OS,const FaultMapParser::FunctionInfoAccessor & FI)127 operator<<(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
operator <<(raw_ostream & OS,const FaultMapParser & FMP)135 raw_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