llvm/lib/ProfileData/SymbolRemappingReader.cpp

   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.starts_with("#") || 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 }