LLVM  8.0.0svn
BlockVerifier.cpp
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1 //===- BlockVerifier.cpp - FDR Block Verifier -----------------------------===//
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 //===----------------------------------------------------------------------===//
10 #include "llvm/Support/Error.h"
11 
12 namespace llvm {
13 namespace xray {
14 namespace {
15 
16 constexpr unsigned long long mask(BlockVerifier::State S) {
17  return 1uLL << static_cast<std::size_t>(S);
18 }
19 
20 constexpr std::size_t number(BlockVerifier::State S) {
21  return static_cast<std::size_t>(S);
22 }
23 
24 StringRef recordToString(BlockVerifier::State R) {
25  switch (R) {
27  return "BufferExtents";
29  return "NewBuffer";
31  return "WallClockTime";
33  return "PIDEntry";
35  return "NewCPUId";
37  return "TSCWrap";
39  return "CustomEvent";
41  return "Function";
43  return "CallArg";
45  return "EndOfBuffer";
47  return "TypedEvent";
50  return "Unknown";
51  }
52  llvm_unreachable("Unkown state!");
53 }
54 
55 struct Transition {
57  std::bitset<number(BlockVerifier::State::StateMax)> ToStates;
58 };
59 
60 } // namespace
61 
62 Error BlockVerifier::transition(State To) {
63  using ToSet = std::bitset<number(State::StateMax)>;
64  static constexpr std::array<const Transition, number(State::StateMax)>
65  TransitionTable{{{State::Unknown,
66  {mask(State::BufferExtents) | mask(State::NewBuffer)}},
67 
68  {State::BufferExtents, {mask(State::NewBuffer)}},
69 
70  {State::NewBuffer, {mask(State::WallClockTime)}},
71 
72  {State::WallClockTime,
73  {mask(State::PIDEntry) | mask(State::NewCPUId)}},
74 
75  {State::PIDEntry, {mask(State::NewCPUId)}},
76 
77  {State::NewCPUId,
78  {mask(State::NewCPUId) | mask(State::TSCWrap) |
79  mask(State::CustomEvent) | mask(State::Function) |
80  mask(State::EndOfBuffer) | mask(State::TypedEvent)}},
81 
82  {State::TSCWrap,
83  {mask(State::TSCWrap) | mask(State::NewCPUId) |
84  mask(State::CustomEvent) | mask(State::Function) |
85  mask(State::EndOfBuffer) | mask(State::TypedEvent)}},
86 
87  {State::CustomEvent,
88  {mask(State::CustomEvent) | mask(State::TSCWrap) |
89  mask(State::NewCPUId) | mask(State::Function) |
90  mask(State::EndOfBuffer) | mask(State::TypedEvent)}},
91 
92  {State::TypedEvent,
93  {mask(State::TypedEvent) | mask(State::TSCWrap) |
94  mask(State::NewCPUId) | mask(State::Function) |
95  mask(State::EndOfBuffer) | mask(State::CustomEvent)}},
96 
97  {State::Function,
98  {mask(State::Function) | mask(State::TSCWrap) |
99  mask(State::NewCPUId) | mask(State::CustomEvent) |
100  mask(State::CallArg) | mask(State::EndOfBuffer) |
101  mask(State::TypedEvent)}},
102 
104  {mask(State::CallArg) | mask(State::Function) |
105  mask(State::TSCWrap) | mask(State::NewCPUId) |
106  mask(State::CustomEvent) | mask(State::EndOfBuffer) |
107  mask(State::TypedEvent)}},
108 
109  {State::EndOfBuffer, {}}}};
110 
111  if (CurrentRecord >= State::StateMax)
112  return createStringError(
113  std::make_error_code(std::errc::executable_format_error),
114  "BUG (BlockVerifier): Cannot find transition table entry for %s, "
115  "transitioning to %s.",
116  recordToString(CurrentRecord).data(), recordToString(To).data());
117 
118  // If we're at an EndOfBuffer record, we ignore anything that follows that
119  // isn't a NewBuffer record.
120  if (CurrentRecord == State::EndOfBuffer && To != State::NewBuffer)
121  return Error::success();
122 
123  auto &Mapping = TransitionTable[number(CurrentRecord)];
124  auto &Destinations = Mapping.ToStates;
125  assert(Mapping.From == CurrentRecord &&
126  "BUG: Wrong index for record mapping.");
127  if ((Destinations & ToSet(mask(To))) == 0)
128  return createStringError(
129  std::make_error_code(std::errc::executable_format_error),
130  "BlockVerifier: Invalid transition from %s to %s.",
131  recordToString(CurrentRecord).data(), recordToString(To).data());
132 
133  CurrentRecord = To;
134  return Error::success();
135 } // namespace xray
136 
138  return transition(State::BufferExtents);
139 }
140 
142  return transition(State::WallClockTime);
143 }
144 
146  return transition(State::NewCPUId);
147 }
148 
150  return transition(State::TSCWrap);
151 }
152 
154  return transition(State::CustomEvent);
155 }
156 
158  return transition(State::CustomEvent);
159 }
160 
162  return transition(State::TypedEvent);
163 }
164 
166  return transition(State::CallArg);
167 }
168 
169 Error BlockVerifier::visit(PIDRecord &) { return transition(State::PIDEntry); }
170 
172  return transition(State::NewBuffer);
173 }
174 
176  return transition(State::EndOfBuffer);
177 }
178 
180  return transition(State::Function);
181 }
182 
184  // The known terminal conditions are the following:
185  switch (CurrentRecord) {
186  case State::EndOfBuffer:
187  case State::NewCPUId:
188  case State::CustomEvent:
189  case State::TypedEvent:
190  case State::Function:
191  case State::CallArg:
192  case State::TSCWrap:
193  return Error::success();
194  default:
195  return createStringError(
196  std::make_error_code(std::errc::executable_format_error),
197  "BlockVerifier: Invalid terminal condition %s, malformed block.",
198  recordToString(CurrentRecord).data());
199  }
200 }
201 
202 void BlockVerifier::reset() { CurrentRecord = State::Unknown; }
203 
204 } // namespace xray
205 } // namespace llvm
This class represents lattice values for constants.
Definition: AllocatorList.h:24
std::error_code make_error_code(BitcodeError E)
Error visit(BufferExtents &) override
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
static ErrorSuccess success()
Create a success value.
Definition: Error.h:327
BlockVerifier::State From
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Lightweight error class with error context and mandatory checking.
Definition: Error.h:158
std::bitset< number(BlockVerifier::State::StateMax)> ToStates
Error createStringError(std::error_code EC, char const *Fmt, const Ts &... Vals)
Create formatted StringError object.
Definition: Error.h:1162