RemarkLinker.h revision 360784 
1//===-- llvm/Remarks/RemarkLinker.h -----------------------------*- C++/-*-===//
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// This file provides an interface to link together multiple remark files.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_REMARKS_REMARK_LINKER_H
14#define LLVM_REMARKS_REMARK_LINKER_H
15
16#include "llvm/Object/ObjectFile.h"
17#include "llvm/Remarks/Remark.h"
18#include "llvm/Remarks/RemarkFormat.h"
19#include "llvm/Remarks/RemarkStringTable.h"
20#include "llvm/Support/Error.h"
21#include <memory>
22#include <set>
23
24namespace llvm {
25namespace remarks {
26
27struct RemarkLinker {
28private:
29  /// Compare through the pointers.
30  struct RemarkPtrCompare {
31    bool operator()(const std::unique_ptr<Remark> &LHS,
32                    const std::unique_ptr<Remark> &RHS) const {
33      assert(LHS && RHS && "Invalid pointers to compare.");
34      return *LHS < *RHS;
35    };
36  };
37
38  /// The main string table for the remarks.
39  /// Note: all remarks should use the strings from this string table to avoid
40  /// dangling references.
41  StringTable StrTab;
42
43  /// A set holding unique remarks.
44  /// FIXME: std::set is probably not the most appropriate data structure here.
45  /// Due to the limitation of having a move-only key, there isn't another
46  /// obvious choice for now.
47  std::set<std::unique_ptr<Remark>, RemarkPtrCompare> Remarks;
48
49  /// A path to append before the external file path found in remark metadata.
50  Optional<std::string> PrependPath;
51
52  /// Keep this remark. If it's already in the set, discard it.
53  Remark &keep(std::unique_ptr<Remark> Remark);
54
55public:
56  /// Set a path to prepend to the external file path.
57  void setExternalFilePrependPath(StringRef PrependPath);
58
59  /// Link the remarks found in \p Buffer.
60  /// If \p RemarkFormat is not provided, try to deduce it from the metadata in
61  /// \p Buffer.
62  /// \p Buffer can be either a standalone remark container or just
63  /// metadata. This takes care of uniquing and merging the remarks.
64  Error link(StringRef Buffer, Optional<Format> RemarkFormat = None);
65
66  /// Link the remarks found in \p Obj by looking for the right section and
67  /// calling the method above.
68  Error link(const object::ObjectFile &Obj,
69             Optional<Format> RemarkFormat = None);
70
71  /// Serialize the linked remarks to the stream \p OS, using the format \p
72  /// RemarkFormat.
73  /// This clears internal state such as the string table.
74  /// Note: this implies that the serialization mode is standalone.
75  Error serialize(raw_ostream &OS, Format RemarksFormat) const;
76
77  /// Check whether there are any remarks linked.
78  bool empty() const { return Remarks.empty(); }
79
80  /// Return a collection of the linked unique remarks to iterate on.
81  /// Ex:
82  /// for (const Remark &R : RL.remarks() { [...] }
83  using iterator =
84      pointee_iterator<std::set<std::unique_ptr<Remark>>::iterator>;
85
86  iterator_range<iterator> remarks() const {
87    return {Remarks.begin(), Remarks.end()};
88  }
89};
90
91/// Returns a buffer with the contents of the remarks section depending on the
92/// format of the file. If the section doesn't exist, this returns an empty
93/// optional.
94Expected<Optional<StringRef>>
95getRemarksSectionContents(const object::ObjectFile &Obj);
96
97} // end namespace remarks
98} // end namespace llvm
99
100#endif /* LLVM_REMARKS_REMARK_LINKER_H */
101