llvm/tools/llvm-readobj/ObjDumper.cpp

   1 //===-- ObjDumper.cpp - Base dumper class -----------------------*- 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 /// \file
  10 /// This file implements ObjDumper.
  11 ///
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "ObjDumper.h"
  15 #include "llvm-readobj.h"
  16 #include "llvm/Object/Archive.h"
  17 #include "llvm/Object/Decompressor.h"
  18 #include "llvm/Object/ObjectFile.h"
  19 #include "llvm/Support/Error.h"
  20 #include "llvm/Support/FormatVariadic.h"
  21 #include "llvm/Support/ScopedPrinter.h"
  22 #include "llvm/Support/SystemZ/zOSSupport.h"
  23 #include "llvm/Support/raw_ostream.h"
  24 #include <map>
  25
  26 namespace llvm {
  27
  28 static inline Error createError(const Twine &Msg) {
  29   return createStringError(object::object_error::parse_failed, Msg);
  30 }
  31
  32 ObjDumper::ObjDumper(ScopedPrinter &Writer, StringRef ObjName) : W(Writer) {
  33   // Dumper reports all non-critical errors as warnings.
  34   // It does not print the same warning more than once.
  35   WarningHandler = [=](const Twine &Msg) {
  36     if (Warnings.insert(Msg.str()).second)
  37       reportWarning(createError(Msg), ObjName);
  38     return Error::success();
  39   };
  40 }
  41
  42 ObjDumper::~ObjDumper() {}
  43
  44 void ObjDumper::reportUniqueWarning(Error Err) const {
  45   reportUniqueWarning(toString(std::move(Err)));
  46 }
  47
  48 void ObjDumper::reportUniqueWarning(const Twine &Msg) const {
  49   cantFail(WarningHandler(Msg),
  50            "WarningHandler should always return ErrorSuccess");
  51 }
  52
  53 static void printAsPrintable(raw_ostream &W, const uint8_t *Start, size_t Len) {
  54   for (size_t i = 0; i < Len; i++)
  55     W << (isPrint(Start[i]) ? static_cast<char>(Start[i]) : '.');
  56 }
  57
  58 void ObjDumper::printAsStringList(StringRef StringContent,
  59                                   size_t StringDataOffset) {
  60   size_t StrSize = StringContent.size();
  61   if (StrSize == 0)
  62     return;
  63   if (StrSize < StringDataOffset) {
  64     reportUniqueWarning("offset (0x" + Twine::utohexstr(StringDataOffset) +
  65                         ") is past the end of the contents (size 0x" +
  66                         Twine::utohexstr(StrSize) + ")");
  67     return;
  68   }
  69
  70   const uint8_t *StrContent = StringContent.bytes_begin();
  71   // Some formats contain additional metadata at the start which should not be
  72   // interpreted as strings. Skip these bytes, but account for them in the
  73   // string offsets.
  74   const uint8_t *CurrentWord = StrContent + StringDataOffset;
  75   const uint8_t *StrEnd = StringContent.bytes_end();
  76
  77   while (CurrentWord <= StrEnd) {
  78     size_t WordSize = strnlen(reinterpret_cast<const char *>(CurrentWord),
  79                               StrEnd - CurrentWord);
  80     if (!WordSize) {
  81       CurrentWord++;
  82       continue;
  83     }
  84     W.startLine() << format("[%6tx] ", CurrentWord - StrContent);
  85     printAsPrintable(W.getOStream(), CurrentWord, WordSize);
  86     W.getOStream() << '\n';
  87     CurrentWord += WordSize + 1;
  88   }
  89 }
  90
  91 void ObjDumper::printFileSummary(StringRef FileStr, object::ObjectFile &Obj,
  92                                  ArrayRef<std::string> InputFilenames,
  93                                  const object::Archive *A) {
  94   if (!FileStr.empty()) {
  95     W.getOStream() << "\n";
  96     W.printString("File", FileStr);
  97   }
  98   W.printString("Format", Obj.getFileFormatName());
  99   W.printString("Arch", Triple::getArchTypeName(Obj.getArch()));
 100   W.printString("AddressSize",
 101                 std::string(formatv("{0}bit", 8 * Obj.getBytesInAddress())));
 102   this->printLoadName();
 103 }
 104
 105 static std::vector<object::SectionRef>
 106 getSectionRefsByNameOrIndex(const object::ObjectFile &Obj,
 107                             ArrayRef<std::string> Sections) {
 108   std::vector<object::SectionRef> Ret;
 109   std::map<std::string, bool, std::less<>> SecNames;
 110   std::map<unsigned, bool> SecIndices;
 111   unsigned SecIndex;
 112   for (StringRef Section : Sections) {
 113     if (!Section.getAsInteger(0, SecIndex))
 114       SecIndices.emplace(SecIndex, false);
 115     else
 116       SecNames.emplace(std::string(Section), false);
 117   }
 118
 119   SecIndex = Obj.isELF() ? 0 : 1;
 120   for (object::SectionRef SecRef : Obj.sections()) {
 121     StringRef SecName = unwrapOrError(Obj.getFileName(), SecRef.getName());
 122     auto NameIt = SecNames.find(SecName);
 123     if (NameIt != SecNames.end())
 124       NameIt->second = true;
 125     auto IndexIt = SecIndices.find(SecIndex);
 126     if (IndexIt != SecIndices.end())
 127       IndexIt->second = true;
 128     if (NameIt != SecNames.end() || IndexIt != SecIndices.end())
 129       Ret.push_back(SecRef);
 130     SecIndex++;
 131   }
 132
 133   for (const std::pair<const std::string, bool> &S : SecNames)
 134     if (!S.second)
 135       reportWarning(
 136           createError(formatv("could not find section '{0}'", S.first).str()),
 137           Obj.getFileName());
 138
 139   for (std::pair<unsigned, bool> S : SecIndices)
 140     if (!S.second)
 141       reportWarning(
 142           createError(formatv("could not find section {0}", S.first).str()),
 143           Obj.getFileName());
 144
 145   return Ret;
 146 }
 147
 148 static void maybeDecompress(const object::ObjectFile &Obj,
 149                             StringRef SectionName, StringRef &SectionContent,
 150                             SmallString<0> &Out) {
 151   Expected<object::Decompressor> Decompressor = object::Decompressor::create(
 152       SectionName, SectionContent, Obj.isLittleEndian(), Obj.is64Bit());
 153   if (!Decompressor)
 154     reportWarning(Decompressor.takeError(), Obj.getFileName());
 155   else if (auto Err = Decompressor->resizeAndDecompress(Out))
 156     reportWarning(std::move(Err), Obj.getFileName());
 157   else
 158     SectionContent = Out;
 159 }
 160
 161 void ObjDumper::printSectionsAsString(const object::ObjectFile &Obj,
 162                                       ArrayRef<std::string> Sections,
 163                                       bool Decompress) {
 164   SmallString<0> Out;
 165   for (object::SectionRef Section :
 166        getSectionRefsByNameOrIndex(Obj, Sections)) {
 167     StringRef SectionName = unwrapOrError(Obj.getFileName(), Section.getName());
 168     W.getOStream() << '\n';
 169     W.startLine() << "String dump of section '" << SectionName << "':\n";
 170
 171     StringRef SectionContent =
 172         unwrapOrError(Obj.getFileName(), Section.getContents());
 173     if (Decompress && Section.isCompressed())
 174       maybeDecompress(Obj, SectionName, SectionContent, Out);
 175     printAsStringList(SectionContent);
 176   }
 177 }
 178
 179 void ObjDumper::printSectionsAsHex(const object::ObjectFile &Obj,
 180                                    ArrayRef<std::string> Sections,
 181                                    bool Decompress) {
 182   SmallString<0> Out;
 183   for (object::SectionRef Section :
 184        getSectionRefsByNameOrIndex(Obj, Sections)) {
 185     StringRef SectionName = unwrapOrError(Obj.getFileName(), Section.getName());
 186     W.getOStream() << '\n';
 187     W.startLine() << "Hex dump of section '" << SectionName << "':\n";
 188
 189     StringRef SectionContent =
 190         unwrapOrError(Obj.getFileName(), Section.getContents());
 191     if (Decompress && Section.isCompressed())
 192       maybeDecompress(Obj, SectionName, SectionContent, Out);
 193     const uint8_t *SecContent = SectionContent.bytes_begin();
 194     const uint8_t *SecEnd = SecContent + SectionContent.size();
 195
 196     for (const uint8_t *SecPtr = SecContent; SecPtr < SecEnd; SecPtr += 16) {
 197       const uint8_t *TmpSecPtr = SecPtr;
 198       uint8_t i;
 199       uint8_t k;
 200
 201       W.startLine() << format_hex(Section.getAddress() + (SecPtr - SecContent),
 202                                   10);
 203       W.getOStream() << ' ';
 204       for (i = 0; TmpSecPtr < SecEnd && i < 4; ++i) {
 205         for (k = 0; TmpSecPtr < SecEnd && k < 4; k++, TmpSecPtr++) {
 206           uint8_t Val = *(reinterpret_cast<const uint8_t *>(TmpSecPtr));
 207           W.getOStream() << format_hex_no_prefix(Val, 2);
 208         }
 209         W.getOStream() << ' ';
 210       }
 211
 212       // We need to print the correct amount of spaces to match the format.
 213       // We are adding the (4 - i) last rows that are 8 characters each.
 214       // Then, the (4 - i) spaces that are in between the rows.
 215       // Least, if we cut in a middle of a row, we add the remaining characters,
 216       // which is (8 - (k * 2)).
 217       if (i < 4)
 218         W.getOStream() << format("%*c", (4 - i) * 8 + (4 - i), ' ');
 219       if (k < 4)
 220         W.getOStream() << format("%*c", 8 - k * 2, ' ');
 221
 222       TmpSecPtr = SecPtr;
 223       for (i = 0; TmpSecPtr + i < SecEnd && i < 16; ++i)
 224         W.getOStream() << (isPrint(TmpSecPtr[i])
 225                                ? static_cast<char>(TmpSecPtr[i])
 226                                : '.');
 227
 228       W.getOStream() << '\n';
 229     }
 230   }
 231 }
 232
 233 } // namespace llvm