1 //===-- llvm/Remarks/Remark.h - The remark type -----------------*- 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 for parsing remarks in LLVM.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_REMARKS_REMARKPARSER_H
14 #define LLVM_REMARKS_REMARKPARSER_H
15 
16 #include "llvm/ADT/StringRef.h"
17 #include "llvm/Remarks/RemarkFormat.h"
18 #include "llvm/Support/Error.h"
19 #include <memory>
20 
21 namespace llvm {
22 namespace remarks {
23 
24 struct Remark;
25 
26 class EndOfFileError : public ErrorInfo<EndOfFileError> {
27 public:
28   static char ID;
29 
30   EndOfFileError() = default;
31 
32   void log(raw_ostream &OS) const override { OS << "End of file reached."; }
33   std::error_code convertToErrorCode() const override {
34     return inconvertibleErrorCode();
35   }
36 };
37 
38 /// Parser used to parse a raw buffer to remarks::Remark objects.
39 struct RemarkParser {
40   /// The format of the parser.
41   Format ParserFormat;
42   /// Path to prepend when opening an external remark file.
43   std::string ExternalFilePrependPath;
44 
45   RemarkParser(Format ParserFormat) : ParserFormat(ParserFormat) {}
46 
47   /// If no error occurs, this returns a valid Remark object.
48   /// If an error of type EndOfFileError occurs, it is safe to recover from it
49   /// by stopping the parsing.
50   /// If any other error occurs, it should be propagated to the user.
51   /// The pointer should never be null.
52   virtual Expected<std::unique_ptr<Remark>> next() = 0;
53 
54   virtual ~RemarkParser() = default;
55 };
56 
57 /// In-memory representation of the string table parsed from a buffer (e.g. the
58 /// remarks section).
59 struct ParsedStringTable {
60   /// The buffer mapped from the section contents.
61   StringRef Buffer;
62   /// This object has high changes to be std::move'd around, so don't use a
63   /// SmallVector for once.
64   std::vector<size_t> Offsets;
65 
66   ParsedStringTable(StringRef Buffer);
67   /// Disable copy.
68   ParsedStringTable(const ParsedStringTable &) = delete;
69   ParsedStringTable &operator=(const ParsedStringTable &) = delete;
70   /// Should be movable.
71   ParsedStringTable(ParsedStringTable &&) = default;
72   ParsedStringTable &operator=(ParsedStringTable &&) = default;
73 
74   size_t size() const { return Offsets.size(); }
75   Expected<StringRef> operator[](size_t Index) const;
76 };
77 
78 Expected<std::unique_ptr<RemarkParser>> createRemarkParser(Format ParserFormat,
79                                                            StringRef Buf);
80 
81 Expected<std::unique_ptr<RemarkParser>>
82 createRemarkParser(Format ParserFormat, StringRef Buf,
83                    ParsedStringTable StrTab);
84 
85 Expected<std::unique_ptr<RemarkParser>>
86 createRemarkParserFromMeta(Format ParserFormat, StringRef Buf,
87                            Optional<ParsedStringTable> StrTab = None,
88                            Optional<StringRef> ExternalFilePrependPath = None);
89 
90 } // end namespace remarks
91 } // end namespace llvm
92 
93 #endif // LLVM_REMARKS_REMARKPARSER_H
94