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 "Error.h"
16#include "llvm-readobj.h"
17#include "llvm/Object/ObjectFile.h"
18#include "llvm/Support/Error.h"
19#include "llvm/Support/FormatVariadic.h"
20#include "llvm/Support/ScopedPrinter.h"
21#include "llvm/Support/raw_ostream.h"
22#include <map>
23
24namespace llvm {
25
26static inline Error createError(const Twine &Msg) {
27  return createStringError(object::object_error::parse_failed, Msg);
28}
29
30ObjDumper::ObjDumper(ScopedPrinter &Writer) : W(Writer) {}
31
32ObjDumper::~ObjDumper() {
33}
34
35static void printAsPrintable(raw_ostream &W, const uint8_t *Start, size_t Len) {
36  for (size_t i = 0; i < Len; i++)
37    W << (isPrint(Start[i]) ? static_cast<char>(Start[i]) : '.');
38}
39
40static std::vector<object::SectionRef>
41getSectionRefsByNameOrIndex(const object::ObjectFile *Obj,
42                            ArrayRef<std::string> Sections) {
43  std::vector<object::SectionRef> Ret;
44  std::map<std::string, bool> SecNames;
45  std::map<unsigned, bool> SecIndices;
46  unsigned SecIndex;
47  for (StringRef Section : Sections) {
48    if (!Section.getAsInteger(0, SecIndex))
49      SecIndices.emplace(SecIndex, false);
50    else
51      SecNames.emplace(Section, false);
52  }
53
54  SecIndex = Obj->isELF() ? 0 : 1;
55  for (object::SectionRef SecRef : Obj->sections()) {
56    StringRef SecName = unwrapOrError(Obj->getFileName(), SecRef.getName());
57    auto NameIt = SecNames.find(SecName);
58    if (NameIt != SecNames.end())
59      NameIt->second = true;
60    auto IndexIt = SecIndices.find(SecIndex);
61    if (IndexIt != SecIndices.end())
62      IndexIt->second = true;
63    if (NameIt != SecNames.end() || IndexIt != SecIndices.end())
64      Ret.push_back(SecRef);
65    SecIndex++;
66  }
67
68  for (const std::pair<const std::string, bool> &S : SecNames)
69    if (!S.second)
70      reportWarning(
71          createError(formatv("could not find section '{0}'", S.first).str()),
72          Obj->getFileName());
73
74  for (std::pair<unsigned, bool> S : SecIndices)
75    if (!S.second)
76      reportWarning(
77          createError(formatv("could not find section {0}", S.first).str()),
78          Obj->getFileName());
79
80  return Ret;
81}
82
83void ObjDumper::printSectionsAsString(const object::ObjectFile *Obj,
84                                      ArrayRef<std::string> Sections) {
85  bool First = true;
86  for (object::SectionRef Section :
87       getSectionRefsByNameOrIndex(Obj, Sections)) {
88    StringRef SectionName =
89        unwrapOrError(Obj->getFileName(), Section.getName());
90
91    if (!First)
92      W.startLine() << '\n';
93    First = false;
94    W.startLine() << "String dump of section '" << SectionName << "':\n";
95
96    StringRef SectionContent =
97        unwrapOrError(Obj->getFileName(), Section.getContents());
98
99    const uint8_t *SecContent = SectionContent.bytes_begin();
100    const uint8_t *CurrentWord = SecContent;
101    const uint8_t *SecEnd = SectionContent.bytes_end();
102
103    while (CurrentWord <= SecEnd) {
104      size_t WordSize = strnlen(reinterpret_cast<const char *>(CurrentWord),
105                                SecEnd - CurrentWord);
106      if (!WordSize) {
107        CurrentWord++;
108        continue;
109      }
110      W.startLine() << format("[%6tx] ", CurrentWord - SecContent);
111      printAsPrintable(W.startLine(), CurrentWord, WordSize);
112      W.startLine() << '\n';
113      CurrentWord += WordSize + 1;
114    }
115  }
116}
117
118void ObjDumper::printSectionsAsHex(const object::ObjectFile *Obj,
119                                   ArrayRef<std::string> Sections) {
120  bool First = true;
121  for (object::SectionRef Section :
122       getSectionRefsByNameOrIndex(Obj, Sections)) {
123    StringRef SectionName =
124        unwrapOrError(Obj->getFileName(), Section.getName());
125
126    if (!First)
127      W.startLine() << '\n';
128    First = false;
129    W.startLine() << "Hex dump of section '" << SectionName << "':\n";
130
131    StringRef SectionContent =
132        unwrapOrError(Obj->getFileName(), Section.getContents());
133    const uint8_t *SecContent = SectionContent.bytes_begin();
134    const uint8_t *SecEnd = SecContent + SectionContent.size();
135
136    for (const uint8_t *SecPtr = SecContent; SecPtr < SecEnd; SecPtr += 16) {
137      const uint8_t *TmpSecPtr = SecPtr;
138      uint8_t i;
139      uint8_t k;
140
141      W.startLine() << format_hex(Section.getAddress() + (SecPtr - SecContent),
142                                  10);
143      W.startLine() << ' ';
144      for (i = 0; TmpSecPtr < SecEnd && i < 4; ++i) {
145        for (k = 0; TmpSecPtr < SecEnd && k < 4; k++, TmpSecPtr++) {
146          uint8_t Val = *(reinterpret_cast<const uint8_t *>(TmpSecPtr));
147          W.startLine() << format_hex_no_prefix(Val, 2);
148        }
149        W.startLine() << ' ';
150      }
151
152      // We need to print the correct amount of spaces to match the format.
153      // We are adding the (4 - i) last rows that are 8 characters each.
154      // Then, the (4 - i) spaces that are in between the rows.
155      // Least, if we cut in a middle of a row, we add the remaining characters,
156      // which is (8 - (k * 2)).
157      if (i < 4)
158        W.startLine() << format("%*c", (4 - i) * 8 + (4 - i) + (8 - (k * 2)),
159                                ' ');
160
161      TmpSecPtr = SecPtr;
162      for (i = 0; TmpSecPtr + i < SecEnd && i < 16; ++i)
163        W.startLine() << (isPrint(TmpSecPtr[i])
164                              ? static_cast<char>(TmpSecPtr[i])
165                              : '.');
166
167      W.startLine() << '\n';
168    }
169  }
170}
171
172} // namespace llvm
173