llvm-project

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//===- SymbolRemappingReader.cpp - Read symbol remapping file -------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file contains definitions needed for reading and applying symbol
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// remapping files.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/ProfileData/SymbolRemappingReader.h"
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#include "llvm/ADT/StringSwitch.h"
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#include "llvm/ADT/Twine.h"
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#include "llvm/Support/LineIterator.h"
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#include "llvm/Support/MemoryBuffer.h"
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using namespace llvm;
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char SymbolRemappingParseError::ID;
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/// Load a set of name remappings from a text file.
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///
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/// See the documentation at the top of the file for an explanation of
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/// the expected format.
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Error SymbolRemappingReader::read(MemoryBuffer &B) {
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  line_iterator LineIt(B, /*SkipBlanks=*/true, '#');
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  auto ReportError = [&](Twine Msg) {
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    return llvm::make_error<SymbolRemappingParseError>(
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        B.getBufferIdentifier(), LineIt.line_number(), Msg);
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  };
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  for (; !LineIt.is_at_eof(); ++LineIt) {
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    StringRef Line = *LineIt;
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    Line = Line.ltrim(' ');
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    // line_iterator only detects comments starting in column 1.
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    if (Line.starts_with("#") || Line.empty())
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      continue;
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    SmallVector<StringRef, 4> Parts;
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    Line.split(Parts, ' ', /*MaxSplits*/-1, /*KeepEmpty*/false);
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    if (Parts.size() != 3)
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      return ReportError("Expected 'kind mangled_name mangled_name', "
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                         "found '" + Line + "'");
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    using FK = ItaniumManglingCanonicalizer::FragmentKind;
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    std::optional<FK> FragmentKind = StringSwitch<std::optional<FK>>(Parts[0])
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                                         .Case("name", FK::Name)
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                                         .Case("type", FK::Type)
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                                         .Case("encoding", FK::Encoding)
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                                         .Default(std::nullopt);
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    if (!FragmentKind)
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      return ReportError("Invalid kind, expected 'name', 'type', or 'encoding',"
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                         " found '" + Parts[0] + "'");
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    using EE = ItaniumManglingCanonicalizer::EquivalenceError;
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    switch (Canonicalizer.addEquivalence(*FragmentKind, Parts[1], Parts[2])) {
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    case EE::Success:
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      break;
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    case EE::ManglingAlreadyUsed:
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      return ReportError("Manglings '" + Parts[1] + "' and '" + Parts[2] + "' "
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                         "have both been used in prior remappings. Move this "
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                         "remapping earlier in the file.");
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    case EE::InvalidFirstMangling:
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      return ReportError("Could not demangle '" + Parts[1] + "' "
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                         "as a <" + Parts[0] + ">; invalid mangling?");
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    case EE::InvalidSecondMangling:
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      return ReportError("Could not demangle '" + Parts[2] + "' "
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                         "as a <" + Parts[0] + ">; invalid mangling?");
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    }
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  }
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  return Error::success();
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}
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