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 "Error.h"
  16 #include "llvm-readobj.h"
  17 #include "llvm/Object/ObjectFile.h"
  18 #include "llvm/Support/Error.h"
  19 #include "llvm/Support/ScopedPrinter.h"
  20 #include "llvm/Support/raw_ostream.h"
  21
  22 namespace llvm {
  23
  24 ObjDumper::ObjDumper(ScopedPrinter &Writer) : W(Writer) {}
  25
  26 ObjDumper::~ObjDumper() {
  27 }
  28
  29 static void printAsPrintable(raw_ostream &W, const uint8_t *Start, size_t Len) {
  30   for (size_t i = 0; i < Len; i++)
  31     W << (isPrint(Start[i]) ? static_cast<char>(Start[i]) : '.');
  32 }
  33
  34 static Expected<object::SectionRef>
  35 getSecNameOrIndexAsSecRef(const object::ObjectFile *Obj, StringRef SecName) {
  36   char *StrPtr;
  37   long SectionIndex = strtol(SecName.data(), &StrPtr, 10);
  38   object::SectionRef Section;
  39   long SecIndex;
  40   if (Obj->isELF())
  41     SecIndex = 0;
  42   else
  43     SecIndex = 1;
  44   for (object::SectionRef SecRef : Obj->sections()) {
  45     if (*StrPtr) {
  46       StringRef SectionName;
  47
  48       if (std::error_code E = SecRef.getName(SectionName))
  49         return errorCodeToError(E);
  50
  51       if (SectionName == SecName)
  52         return SecRef;
  53     } else if (SecIndex == SectionIndex)
  54       return SecRef;
  55
  56     SecIndex++;
  57   }
  58   return make_error<StringError>("invalid section reference",
  59                                  object::object_error::parse_failed);
  60 }
  61
  62 void ObjDumper::printSectionAsString(const object::ObjectFile *Obj,
  63                                      StringRef SecName) {
  64   Expected<object::SectionRef> SectionRefOrError =
  65       getSecNameOrIndexAsSecRef(Obj, SecName);
  66   if (!SectionRefOrError)
  67     error(std::move(SectionRefOrError));
  68   object::SectionRef Section = *SectionRefOrError;
  69   StringRef SectionName;
  70
  71   if (std::error_code E = Section.getName(SectionName))
  72     error(E);
  73   W.startLine() << "String dump of section '" << SectionName << "':\n";
  74
  75   StringRef SectionContent;
  76   Section.getContents(SectionContent);
  77
  78   const uint8_t *SecContent = SectionContent.bytes_begin();
  79   const uint8_t *CurrentWord = SecContent;
  80   const uint8_t *SecEnd = SectionContent.bytes_end();
  81
  82   while (CurrentWord <= SecEnd) {
  83     size_t WordSize = strnlen(reinterpret_cast<const char *>(CurrentWord),
  84                               SecEnd - CurrentWord);
  85     if (!WordSize) {
  86       CurrentWord++;
  87       continue;
  88     }
  89     W.startLine() << format("[%6tx] ", CurrentWord - SecContent);
  90     printAsPrintable(W.startLine(), CurrentWord, WordSize);
  91     W.startLine() << '\n';
  92     CurrentWord += WordSize + 1;
  93   }
  94 }
  95
  96 void ObjDumper::printSectionAsHex(const object::ObjectFile *Obj,
  97                                   StringRef SecName) {
  98   Expected<object::SectionRef> SectionRefOrError =
  99       getSecNameOrIndexAsSecRef(Obj, SecName);
 100   if (!SectionRefOrError)
 101     error(std::move(SectionRefOrError));
 102   object::SectionRef Section = *SectionRefOrError;
 103   StringRef SectionName;
 104
 105   if (std::error_code E = Section.getName(SectionName))
 106     error(E);
 107   W.startLine() << "Hex dump of section '" << SectionName << "':\n";
 108
 109   StringRef SectionContent;
 110   Section.getContents(SectionContent);
 111   const uint8_t *SecContent = SectionContent.bytes_begin();
 112   const uint8_t *SecEnd = SecContent + SectionContent.size();
 113
 114   for (const uint8_t *SecPtr = SecContent; SecPtr < SecEnd; SecPtr += 16) {
 115     const uint8_t *TmpSecPtr = SecPtr;
 116     uint8_t i;
 117     uint8_t k;
 118
 119     W.startLine() << format_hex(Section.getAddress() + (SecPtr - SecContent),
 120                                 10);
 121     W.startLine() << ' ';
 122     for (i = 0; TmpSecPtr < SecEnd && i < 4; ++i) {
 123       for (k = 0; TmpSecPtr < SecEnd && k < 4; k++, TmpSecPtr++) {
 124         uint8_t Val = *(reinterpret_cast<const uint8_t *>(TmpSecPtr));
 125         W.startLine() << format_hex_no_prefix(Val, 2);
 126       }
 127       W.startLine() << ' ';
 128     }
 129
 130     // We need to print the correct amount of spaces to match the format.
 131     // We are adding the (4 - i) last rows that are 8 characters each.
 132     // Then, the (4 - i) spaces that are in between the rows.
 133     // Least, if we cut in a middle of a row, we add the remaining characters,
 134     // which is (8 - (k * 2))
 135     if (i < 4)
 136       W.startLine() << format("%*c", (4 - i) * 8 + (4 - i) + (8 - (k * 2)),
 137                               ' ');
 138
 139     TmpSecPtr = SecPtr;
 140     for (i = 0; TmpSecPtr + i < SecEnd && i < 16; ++i)
 141       W.startLine() << (isPrint(TmpSecPtr[i]) ? static_cast<char>(TmpSecPtr[i])
 142                                               : '.');
 143
 144     W.startLine() << '\n';
 145   }
 146 }
 147
 148 } // namespace llvm