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/ObjectFile.h"
17 #include "llvm/Support/Error.h"
18 #include "llvm/Support/FormatVariadic.h"
19 #include "llvm/Support/ScopedPrinter.h"
20 #include "llvm/Support/raw_ostream.h"
21 #include <map>
22 
23 namespace llvm {
24 
25 static inline Error createError(const Twine &Msg) {
26   return createStringError(object::object_error::parse_failed, Msg);
27 }
28 
29 ObjDumper::ObjDumper(ScopedPrinter &Writer, StringRef ObjName) : W(Writer) {
30   // Dumper reports all non-critical errors as warnings.
31   // It does not print the same warning more than once.
32   WarningHandler = [=](const Twine &Msg) {
33     if (Warnings.insert(Msg.str()).second)
34       reportWarning(createError(Msg), ObjName);
35     return Error::success();
36   };
37 }
38 
39 ObjDumper::~ObjDumper() {}
40 
41 void ObjDumper::reportUniqueWarning(Error Err) const {
42   reportUniqueWarning(toString(std::move(Err)));
43 }
44 
45 void ObjDumper::reportUniqueWarning(const Twine &Msg) const {
46   cantFail(WarningHandler(Msg),
47            "WarningHandler should always return ErrorSuccess");
48 }
49 
50 static void printAsPrintable(raw_ostream &W, const uint8_t *Start, size_t Len) {
51   for (size_t i = 0; i < Len; i++)
52     W << (isPrint(Start[i]) ? static_cast<char>(Start[i]) : '.');
53 }
54 
55 static std::vector<object::SectionRef>
56 getSectionRefsByNameOrIndex(const object::ObjectFile &Obj,
57                             ArrayRef<std::string> Sections) {
58   std::vector<object::SectionRef> Ret;
59   std::map<std::string, bool> SecNames;
60   std::map<unsigned, bool> SecIndices;
61   unsigned SecIndex;
62   for (StringRef Section : Sections) {
63     if (!Section.getAsInteger(0, SecIndex))
64       SecIndices.emplace(SecIndex, false);
65     else
66       SecNames.emplace(std::string(Section), false);
67   }
68 
69   SecIndex = Obj.isELF() ? 0 : 1;
70   for (object::SectionRef SecRef : Obj.sections()) {
71     StringRef SecName = unwrapOrError(Obj.getFileName(), SecRef.getName());
72     auto NameIt = SecNames.find(std::string(SecName));
73     if (NameIt != SecNames.end())
74       NameIt->second = true;
75     auto IndexIt = SecIndices.find(SecIndex);
76     if (IndexIt != SecIndices.end())
77       IndexIt->second = true;
78     if (NameIt != SecNames.end() || IndexIt != SecIndices.end())
79       Ret.push_back(SecRef);
80     SecIndex++;
81   }
82 
83   for (const std::pair<const std::string, bool> &S : SecNames)
84     if (!S.second)
85       reportWarning(
86           createError(formatv("could not find section '{0}'", S.first).str()),
87           Obj.getFileName());
88 
89   for (std::pair<unsigned, bool> S : SecIndices)
90     if (!S.second)
91       reportWarning(
92           createError(formatv("could not find section {0}", S.first).str()),
93           Obj.getFileName());
94 
95   return Ret;
96 }
97 
98 void ObjDumper::printSectionsAsString(const object::ObjectFile &Obj,
99                                       ArrayRef<std::string> Sections) {
100   bool First = true;
101   for (object::SectionRef Section :
102        getSectionRefsByNameOrIndex(Obj, Sections)) {
103     StringRef SectionName = unwrapOrError(Obj.getFileName(), Section.getName());
104 
105     if (!First)
106       W.startLine() << '\n';
107     First = false;
108     W.startLine() << "String dump of section '" << SectionName << "':\n";
109 
110     StringRef SectionContent =
111         unwrapOrError(Obj.getFileName(), Section.getContents());
112 
113     const uint8_t *SecContent = SectionContent.bytes_begin();
114     const uint8_t *CurrentWord = SecContent;
115     const uint8_t *SecEnd = SectionContent.bytes_end();
116 
117     while (CurrentWord <= SecEnd) {
118       size_t WordSize = strnlen(reinterpret_cast<const char *>(CurrentWord),
119                                 SecEnd - CurrentWord);
120       if (!WordSize) {
121         CurrentWord++;
122         continue;
123       }
124       W.startLine() << format("[%6tx] ", CurrentWord - SecContent);
125       printAsPrintable(W.startLine(), CurrentWord, WordSize);
126       W.startLine() << '\n';
127       CurrentWord += WordSize + 1;
128     }
129   }
130 }
131 
132 void ObjDumper::printSectionsAsHex(const object::ObjectFile &Obj,
133                                    ArrayRef<std::string> Sections) {
134   bool First = true;
135   for (object::SectionRef Section :
136        getSectionRefsByNameOrIndex(Obj, Sections)) {
137     StringRef SectionName = unwrapOrError(Obj.getFileName(), Section.getName());
138 
139     if (!First)
140       W.startLine() << '\n';
141     First = false;
142     W.startLine() << "Hex dump of section '" << SectionName << "':\n";
143 
144     StringRef SectionContent =
145         unwrapOrError(Obj.getFileName(), Section.getContents());
146     const uint8_t *SecContent = SectionContent.bytes_begin();
147     const uint8_t *SecEnd = SecContent + SectionContent.size();
148 
149     for (const uint8_t *SecPtr = SecContent; SecPtr < SecEnd; SecPtr += 16) {
150       const uint8_t *TmpSecPtr = SecPtr;
151       uint8_t i;
152       uint8_t k;
153 
154       W.startLine() << format_hex(Section.getAddress() + (SecPtr - SecContent),
155                                   10);
156       W.startLine() << ' ';
157       for (i = 0; TmpSecPtr < SecEnd && i < 4; ++i) {
158         for (k = 0; TmpSecPtr < SecEnd && k < 4; k++, TmpSecPtr++) {
159           uint8_t Val = *(reinterpret_cast<const uint8_t *>(TmpSecPtr));
160           W.startLine() << format_hex_no_prefix(Val, 2);
161         }
162         W.startLine() << ' ';
163       }
164 
165       // We need to print the correct amount of spaces to match the format.
166       // We are adding the (4 - i) last rows that are 8 characters each.
167       // Then, the (4 - i) spaces that are in between the rows.
168       // Least, if we cut in a middle of a row, we add the remaining characters,
169       // which is (8 - (k * 2)).
170       if (i < 4)
171         W.startLine() << format("%*c", (4 - i) * 8 + (4 - i), ' ');
172       if (k < 4)
173         W.startLine() << format("%*c", 8 - k * 2, ' ');
174 
175       TmpSecPtr = SecPtr;
176       for (i = 0; TmpSecPtr + i < SecEnd && i < 16; ++i)
177         W.startLine() << (isPrint(TmpSecPtr[i])
178                               ? static_cast<char>(TmpSecPtr[i])
179                               : '.');
180 
181       W.startLine() << '\n';
182     }
183   }
184 }
185 
186 } // namespace llvm
187