LLVM  10.0.0svn
Trace.h
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1 //===- Trace.h - XRay Trace Abstraction -----------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Defines the XRay Trace class representing records in an XRay trace file.
10 //
11 //===----------------------------------------------------------------------===//
12 #ifndef LLVM_XRAY_TRACE_H
13 #define LLVM_XRAY_TRACE_H
14 
15 #include <cstdint>
16 #include <vector>
17 
18 #include "llvm/ADT/StringRef.h"
20 #include "llvm/Support/Error.h"
21 #include "llvm/XRay/XRayRecord.h"
22 
23 namespace llvm {
24 namespace xray {
25 
26 /// A Trace object represents the records that have been loaded from XRay
27 /// log files generated by instrumented binaries. We encapsulate the logic of
28 /// reading the traces in factory functions that populate the Trace object
29 /// appropriately.
30 ///
31 /// Trace objects provide an accessor to an XRayFileHeader which says more about
32 /// details of the file from which the XRay trace was loaded from.
33 ///
34 /// Usage:
35 ///
36 /// if (auto TraceOrErr = loadTraceFile("xray-log.something.xray")) {
37 /// auto& T = *TraceOrErr;
38 /// // T.getFileHeader() will provide information from the trace header.
39 /// for (const XRayRecord &R : T) {
40 /// // ... do something with R here.
41 /// }
42 /// } else {
43 /// // Handle the error here.
44 /// }
45 ///
46 class Trace {
47  XRayFileHeader FileHeader;
48  using RecordVector = std::vector<XRayRecord>;
49  RecordVector Records;
50 
51  typedef std::vector<XRayRecord>::const_iterator citerator;
52 
53  friend Expected<Trace> loadTrace(const DataExtractor &, bool);
54 
55 public:
56  using size_type = RecordVector::size_type;
57  using value_type = RecordVector::value_type;
58  using const_iterator = RecordVector::const_iterator;
59 
60  /// Provides access to the loaded XRay trace file header.
61  const XRayFileHeader &getFileHeader() const { return FileHeader; }
62 
63  const_iterator begin() const { return Records.begin(); }
64  const_iterator end() const { return Records.end(); }
65  bool empty() const { return Records.empty(); }
66  size_type size() const { return Records.size(); }
67 };
68 
69 /// This function will attempt to load XRay trace records from the provided
70 /// |Filename|.
71 Expected<Trace> loadTraceFile(StringRef Filename, bool Sort = false);
72 
73 /// This function will attempt to load XRay trace records from the provided
74 /// DataExtractor.
75 Expected<Trace> loadTrace(const DataExtractor &Extractor, bool Sort = false);
76 
77 } // namespace xray
78 } // namespace llvm
79 
80 #endif // LLVM_XRAY_TRACE_H
friend Expected< Trace > loadTrace(const DataExtractor &, bool)
This function will attempt to load XRay trace records from the provided DataExtractor.
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Expected< Trace > loadTraceFile(StringRef Filename, bool Sort=false)
This function will attempt to load XRay trace records from the provided |Filename|.
Definition: Trace.cpp:380
RecordVector::size_type size_type
Definition: Trace.h:56
Tagged union holding either a T or a Error.
Definition: yaml2obj.h:21
RecordVector::const_iterator const_iterator
Definition: Trace.h:58
const_iterator end() const
Definition: Trace.h:64
A Trace object represents the records that have been loaded from XRay log files generated by instrume...
Definition: Trace.h:46
bool empty() const
Definition: Trace.h:65
const_iterator begin() const
Definition: Trace.h:63
RecordVector::value_type value_type
Definition: Trace.h:57
const XRayFileHeader & getFileHeader() const
Provides access to the loaded XRay trace file header.
Definition: Trace.h:61
size_type size() const
Definition: Trace.h:66
XRay traces all have a header providing some top-matter information useful to help tools determine ho...
Definition: XRayRecord.h:27
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48