1 //===- SymbolRemappingReader.cpp - Read symbol remapping file -------------===//
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 contains definitions needed for reading and applying symbol
10 // remapping files.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/ProfileData/SymbolRemappingReader.h"
15 #include "llvm/ADT/StringSwitch.h"
16 #include "llvm/ADT/Twine.h"
17 #include "llvm/Support/LineIterator.h"
18 #include "llvm/Support/MemoryBuffer.h"
19 
20 using namespace llvm;
21 
22 char SymbolRemappingParseError::ID;
23 
24 /// Load a set of name remappings from a text file.
25 ///
26 /// See the documentation at the top of the file for an explanation of
27 /// the expected format.
28 Error SymbolRemappingReader::read(MemoryBuffer &B) {
29   line_iterator LineIt(B, /*SkipBlanks=*/true, '#');
30 
31   auto ReportError = [&](Twine Msg) {
32     return llvm::make_error<SymbolRemappingParseError>(
33         B.getBufferIdentifier(), LineIt.line_number(), Msg);
34   };
35 
36   for (; !LineIt.is_at_eof(); ++LineIt) {
37     StringRef Line = *LineIt;
38     Line = Line.ltrim(' ');
39     // line_iterator only detects comments starting in column 1.
40     if (Line.startswith("#") || Line.empty())
41       continue;
42 
43     SmallVector<StringRef, 4> Parts;
44     Line.split(Parts, ' ', /*MaxSplits*/-1, /*KeepEmpty*/false);
45 
46     if (Parts.size() != 3)
47       return ReportError("Expected 'kind mangled_name mangled_name', "
48                          "found '" + Line + "'");
49 
50     using FK = ItaniumManglingCanonicalizer::FragmentKind;
51     std::optional<FK> FragmentKind = StringSwitch<std::optional<FK>>(Parts[0])
52                                          .Case("name", FK::Name)
53                                          .Case("type", FK::Type)
54                                          .Case("encoding", FK::Encoding)
55                                          .Default(std::nullopt);
56     if (!FragmentKind)
57       return ReportError("Invalid kind, expected 'name', 'type', or 'encoding',"
58                          " found '" + Parts[0] + "'");
59 
60     using EE = ItaniumManglingCanonicalizer::EquivalenceError;
61     switch (Canonicalizer.addEquivalence(*FragmentKind, Parts[1], Parts[2])) {
62     case EE::Success:
63       break;
64 
65     case EE::ManglingAlreadyUsed:
66       return ReportError("Manglings '" + Parts[1] + "' and '" + Parts[2] + "' "
67                          "have both been used in prior remappings. Move this "
68                          "remapping earlier in the file.");
69 
70     case EE::InvalidFirstMangling:
71       return ReportError("Could not demangle '" + Parts[1] + "' "
72                          "as a <" + Parts[0] + ">; invalid mangling?");
73 
74     case EE::InvalidSecondMangling:
75       return ReportError("Could not demangle '" + Parts[2] + "' "
76                          "as a <" + Parts[0] + ">; invalid mangling?");
77     }
78   }
79 
80   return Error::success();
81 }
82