Implements low-level object file format specific output for COFF and
ELF with support for:

- File headers
- Section headers + data
- Relocations
- Symbols
- Unwind data (only COFF/Win64)

The output format follows a few rules:
- Values are almost always output one per line (as elf-dump/coff-dump already do). - Many values are translated to something readable (like enum names), with the raw value in parentheses.
- Hex numbers are output in uppercase, prefixed with "0x".
- Flags are sorted alphabetically.
- Lists and groups are always delimited.

Example output:
---------- snip ----------
Sections [
  Section {
    Index: 1
    Name: .text (5)
    Type: SHT_PROGBITS (0x1)
    Flags [ (0x6)
      SHF_ALLOC (0x2)
      SHF_EXECINSTR (0x4)
    ]
    Address: 0x0
    Offset: 0x40
    Size: 33
    Link: 0
    Info: 0
    AddressAlignment: 16
    EntrySize: 0
    Relocations [
      0x6 R_386_32 .rodata.str1.1 0x0
      0xB R_386_PC32 puts 0x0
      0x12 R_386_32 .rodata.str1.1 0x0
      0x17 R_386_PC32 puts 0x0
    ]
    SectionData (
      0000: 83EC04C7 04240000 0000E8FC FFFFFFC7  |.....$..........|
      0010: 04240600 0000E8FC FFFFFF31 C083C404  |.$.........1....|
      0020: C3                                   |.|
    )
  }
]
---------- snip ----------

Relocations and symbols can be output standalone or together with the section header as displayed in the example.
This feature set supports all tests in test/MC/COFF and test/MC/ELF (and I suspect all additional tests using elf-dump), making elf-dump and coff-dump deprecated.

Patch by Nico Rieck!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178679 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-readobj/StreamWriter.cpp b/tools/llvm-readobj/StreamWriter.cpp
new file mode 100644
index 0000000..8718112
--- /dev/null
+++ b/tools/llvm-readobj/StreamWriter.cpp
@@ -0,0 +1,79 @@
+#include "StreamWriter.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/Format.h"
+#include <cctype>
+
+using namespace llvm::support;
+
+namespace llvm {
+
+raw_ostream &operator<<(raw_ostream &OS, const HexNumber& Value) {
+  uint64_t N = Value.Value;
+  // Zero is a special case.
+  if (N == 0)
+    return OS << "0x0";
+
+  char NumberBuffer[20];
+  char *EndPtr = NumberBuffer + sizeof(NumberBuffer);
+  char *CurPtr = EndPtr;
+
+  while (N) {
+    uintptr_t X = N % 16;
+    *--CurPtr = (X < 10 ? '0' + X : 'A' + X - 10);
+    N /= 16;
+  }
+
+  OS << "0x";
+  return OS.write(CurPtr, EndPtr - CurPtr);
+}
+
+void StreamWriter::printBinaryImpl(StringRef Label, StringRef Str,
+                                   ArrayRef<uint8_t> Data, bool Block) {
+  if (Data.size() > 16)
+    Block = true;
+
+  if (Block) {
+    startLine() << Label;
+    if (Str.size() > 0)
+      OS << ": " << Str;
+    OS << " (\n";
+    for (size_t addr = 0, end = Data.size(); addr < end; addr += 16) {
+      startLine() << format("  %04" PRIX64 ": ", uint64_t(addr));
+      // Dump line of hex.
+      for (size_t i = 0; i < 16; ++i) {
+        if (i != 0 && i % 4 == 0)
+          OS << ' ';
+        if (addr + i < end)
+          OS << hexdigit((Data[addr + i] >> 4) & 0xF, false)
+             << hexdigit(Data[addr + i] & 0xF, false);
+        else
+          OS << "  ";
+      }
+      // Print ascii.
+      OS << "  |";
+      for (std::size_t i = 0; i < 16 && addr + i < end; ++i) {
+        if (std::isprint(Data[addr + i] & 0xFF))
+          OS << Data[addr + i];
+        else
+          OS << ".";
+      }
+      OS << "|\n";
+    }
+
+    startLine() << ")\n";
+  } else {
+    startLine() << Label << ":";
+    if (Str.size() > 0)
+      OS << " " << Str;
+    OS << " (";
+    for (size_t i = 0; i < Data.size(); ++i) {
+      if (i > 0)
+        OS << " ";
+
+      OS << format("%02X", static_cast<int>(Data[i]));
+    }
+    OS << ")\n";
+  }
+}
+
+} // namespace llvm