[llvm-readobj] Implement LLVM style printer for --notes

[rupprecht]

Summary

Port the GNU style printNotes method to the LLVMStyle subclass.

This is basically just a heavy refactor so that the note parsing/formatting logic from the GNUStyle::printNotes can be shared with LLVMStyle::printNotes.

[MaskRay]

tools/llvm-readobj/ELFDumper.cpp

4534

Descriptor.size() is unnecessary.

printGNUNoteLLVMStyle<ELFT>(Type, Descriptor, W); The function signature can be changed accordingly.

4540

ditto

[MaskRay]

tools/llvm-readobj/ELFDumper.cpp

3668

How about #include "llvm/Support/FormatVariadic.h"

formatv("0x{0:x}", *(const typename ELFT::Addr *)Data.data())

On LP64 Linux uint64_t should (best) use %lx

[rupprecht]

• Remove unnecessary size parameter

[rupprecht]

tools/llvm-readobj/ELFDumper.cpp

3668

I'm able to use formatv("{0:x}", ...) but the uint64_t cast still seems necessary to get hex formatting.
(Note: "x" includes the "0x" part by default)

[rupprecht]

• Use formatv

test/tools/llvm-readobj/gnu-notes.test

 # RUN: yaml2obj %s > %t.so
-# RUN: llvm-readobj -elf-output-style GNU --notes %t.so | FileCheck %s
+# RUN: llvm-readobj -elf-output-style GNU --notes %t.so | FileCheck %s --check-prefix=GNU
+# RUN: llvm-readobj -elf-output-style LLVM --notes %t.so | FileCheck %s --check-prefix=LLVM
 
-# CHECK: Displaying notes found at file offset 0x00000300 with length 0x00000020:
-# CHECK:   Owner                 Data size       Description
-# CHECK:   GNU                  0x00000010       NT_GNU_BUILD_ID (unique build ID bitstring)
-# CHECK:     Build ID: 4fcb712aa6387724a9f465a32cd8c14b
+# GNU:      Displaying notes found at file offset 0x00000340 with length 0x00000020:
+# GNU-NEXT:   Owner                 Data size       Description
+# GNU-NEXT:   GNU                   0x00000010      NT_GNU_ABI_TAG (ABI version tag)
+# GNU-NEXT:     OS: Linux, ABI: 2.6.32
 
-# CHECK: Displaying notes found at file offset 0x0000036c with length 0x0000001c:
-# CHECK:   Owner                 Data size       Description
-# CHECK:   GNU                  0x00000009       NT_GNU_GOLD_VERSION (gold version)
-# CHECK:     Version: gold 1.11
+# GNU:      Displaying notes found at file offset 0x00000360 with length 0x00000020:
+# GNU-NEXT:   Owner                 Data size       Description
+# GNU-NEXT:   GNU                  0x00000010       NT_GNU_BUILD_ID (unique build ID bitstring)
+# GNU-NEXT:     Build ID: 4fcb712aa6387724a9f465a32cd8c14b
+
+# GNU:      Displaying notes found at file offset 0x000003cc with length 0x0000001c:
+# GNU-NEXT:   Owner                 Data size       Description
+# GNU-NEXT:   GNU                  0x00000009       NT_GNU_GOLD_VERSION (gold version)
+# GNU-NEXT:     Version: gold 1.11
+
+# LLVM:      Notes [
+# LLVM-NEXT:   NoteSection {
+# LLVM-NEXT:     Offset: 0x340
+# LLVM-NEXT:     Size: 0x20
+# LLVM-NEXT:     Note {
+# LLVM-NEXT:       Owner: GNU
+# LLVM-NEXT:       Data size: 0x10
+# LLVM-NEXT:       Type: NT_GNU_ABI_TAG (ABI version tag)
+# LLVM-NEXT:       OS: Linux
+# LLVM-NEXT:       ABI: 2.6.32
+# LLVM-NEXT:     }
+# LLVM-NEXT:   }
+# LLVM-NEXT:   NoteSection {
+# LLVM-NEXT:     Offset: 0x360
+# LLVM-NEXT:     Size: 0x20
+# LLVM-NEXT:     Note {
+# LLVM-NEXT:       Owner: GNU
+# LLVM-NEXT:       Data size: 0x10
+# LLVM-NEXT:       Type: NT_GNU_BUILD_ID (unique build ID bitstring)
+# LLVM-NEXT:       Build ID: 4fcb712aa6387724a9f465a32cd8c14b
+# LLVM-NEXT:     }
+# LLVM-NEXT:   }
+# LLVM-NEXT:   NoteSection {
+# LLVM-NEXT:     Offset: 0x3CC
+# LLVM-NEXT:     Size: 0x1C
+# LLVM-NEXT:     Note {
+# LLVM-NEXT:       Owner: GNU
+# LLVM-NEXT:       Data size: 0x9
+# LLVM-NEXT:       Type: NT_GNU_GOLD_VERSION (gold version)
+# LLVM-NEXT:       Version: gold 1.11
+# LLVM-NEXT:     }
+# LLVM-NEXT:   }
+# LLVM-NEXT: ]
 
 --- !ELF
 FileHeader:
   Class:           ELFCLASS64
   Data:            ELFDATA2LSB
   Type:            ET_EXEC
   Machine:         EM_X86_64
 Sections:
+  - Name:            .note.ABI-tag
+    Type:            SHT_NOTE
+    AddressAlign:    0x0000000000000004
+    Content:         040000001000000001000000474E550000000000020000000600000020000000
   - Name:            .note.gnu.build-id
     Type:            SHT_NOTE
     Flags:           [ SHF_ALLOC ]
     Address:         0x0000000000400120
     AddressAlign:    0x0000000000000004
     Content:         040000001000000003000000474E55004FCB712AA6387724A9F465A32CD8C14B
   - Name:            .text
     Type:            SHT_PROGBITS

test/tools/llvm-readobj/note-gnu-property.s

 // REQUIRES: x86-registered-target
 // RUN: llvm-mc -filetype=obj -triple x86_64-pc-linux-gnu %s -o %t
-// RUN: llvm-readobj -elf-output-style GNU --notes %t | FileCheck %s
+// RUN: llvm-readobj -elf-output-style GNU --notes %t | FileCheck %s --check-prefix=GNU
+// RUN: llvm-readobj -elf-output-style LLVM --notes %t | FileCheck %s --check-prefix=LLVM
 
-// CHECK:      Displaying notes found at file offset 0x00000040 with length 0x000000b8:
-// CHECK-NEXT:   Owner                 Data size       Description
-// CHECK-NEXT:   GNU                   0x000000a8      NT_GNU_PROPERTY_TYPE_0 (property note)
-// CHECK-NEXT:     Properties:  stack size: 0x100
-// CHECK-NEXT:     stack size: 0x100
-// CHECK-NEXT:     no copy on protected
-// CHECK-NEXT:     X86 features: SHSTK
-// CHECK-NEXT:     X86 features: IBT, SHSTK
-// CHECK-NEXT:     X86 features: none
-// CHECK-NEXT:     <application-specific type 0xfefefefe>
-// CHECK-NEXT:     stack size: <corrupt length: 0x0>
-// CHECK-NEXT:     stack size: <corrupt length: 0x4> 
-// CHECK-NEXT:     no copy on protected <corrupt length: 0x1>
-// CHECK-NEXT:     X86 features: <corrupt length: 0x0>
-// CHECK-NEXT:     X86 features: IBT, <unknown flags: 0xf000f000f000f000>
-// CHECK-NEXT:     <corrupt type (0x2) datasz: 0x1>
+// GNU:      Displaying notes found at file offset 0x00000040 with length 0x000000b8:
+// GNU-NEXT:   Owner                 Data size       Description
+// GNU-NEXT:   GNU                   0x000000a8      NT_GNU_PROPERTY_TYPE_0 (property note)
+// GNU-NEXT:     Properties:  stack size: 0x100
+// GNU-NEXT:     stack size: 0x100
+// GNU-NEXT:     no copy on protected
+// GNU-NEXT:     X86 features: SHSTK
+// GNU-NEXT:     X86 features: IBT, SHSTK
+// GNU-NEXT:     X86 features: none
+// GNU-NEXT:     <application-specific type 0xfefefefe>
+// GNU-NEXT:     stack size: <corrupt length: 0x0>
+// GNU-NEXT:     stack size: <corrupt length: 0x4>
+// GNU-NEXT:     no copy on protected <corrupt length: 0x1>
+// GNU-NEXT:     X86 features: <corrupt length: 0x0>
+// GNU-NEXT:     X86 features: IBT, <unknown flags: 0xf000f000f000f000>
+// GNU-NEXT:     <corrupt type (0x2) datasz: 0x1>
+
+// LLVM:      Notes [
+// LLVM-NEXT:   NoteSection {
+// LLVM-NEXT:     Offset: 0x40
+// LLVM-NEXT:     Size: 0xB8
+// LLVM-NEXT:     Note {
+// LLVM-NEXT:       Owner: GNU
+// LLVM-NEXT:       Data size: 0xA8
+// LLVM-NEXT:       Type: NT_GNU_PROPERTY_TYPE_0 (property note)
+// LLVM-NEXT:       Property [
+// LLVM-NEXT:         stack size: 0x100
+// LLVM-NEXT:         stack size: 0x100
+// LLVM-NEXT:         no copy on protected
+// LLVM-NEXT:         X86 features: SHSTK
+// LLVM-NEXT:         X86 features: IBT, SHSTK
+// LLVM-NEXT:         X86 features: none
+// LLVM-NEXT:         <application-specific type 0xfefefefe>
+// LLVM-NEXT:         stack size: <corrupt length: 0x0>
+// LLVM-NEXT:         stack size: <corrupt length: 0x4>
+// LLVM-NEXT:         no copy on protected <corrupt length: 0x1>
+// LLVM-NEXT:         X86 features: <corrupt length: 0x0>
+// LLVM-NEXT:         X86 features: IBT, <unknown flags: 0xf000f000f000f000>
+// LLVM-NEXT:         <corrupt type (0x2) datasz: 0x1>
+// LLVM-NEXT:       ]
+// LLVM-NEXT:     }
+// LLVM-NEXT:   }
+// LLVM-NEXT: ]
 
 .section ".note.gnu.property", "a"
 .align 4 
   .long 4           /* Name length is always 4 ("GNU") */
   .long end - begin /* Data length */
   .long 5           /* Type: NT_GNU_PROPERTY_TYPE_0 */
   .asciz "GNU"      /* Name */
   .p2align 3

test/tools/llvm-readobj/note-gnu-property2.s

 // REQUIRES: x86-registered-target
 // RUN: llvm-mc -filetype=obj -triple x86_64-pc-linux-gnu %s -o %t
-// RUN: llvm-readobj -elf-output-style GNU --notes %t | FileCheck %s
+// RUN: llvm-readobj -elf-output-style GNU --notes %t | FileCheck %s --check-prefix=GNU
+// RUN: llvm-readobj -elf-output-style LLVM --notes %t | FileCheck %s --check-prefix=LLVM
 
-// CHECK:      Displaying notes found at file offset 0x00000040 with length 0x00000014:
-// CHECK-NEXT:   Owner                 Data size       Description
-// CHECK-NEXT:   GNU                   0x00000004      NT_GNU_PROPERTY_TYPE_0 (property note)
-// CHECK-NEXT:     Properties:  <corrupted GNU_PROPERTY_TYPE_0>
+// GNU:      Displaying notes found at file offset 0x00000040 with length 0x00000014:
+// GNU-NEXT:   Owner                 Data size       Description
+// GNU-NEXT:   GNU                   0x00000004      NT_GNU_PROPERTY_TYPE_0 (property note)
+// GNU-NEXT:     Properties:  <corrupted GNU_PROPERTY_TYPE_0>
+
+// LLVM:      Notes [
+// LLVM-NEXT:   NoteSection {
+// LLVM-NEXT:     Offset: 0x40
+// LLVM-NEXT:     Size: 0x14
+// LLVM-NEXT:     Note {
+// LLVM-NEXT:       Owner: GNU
+// LLVM-NEXT:       Data size: 0x4
+// LLVM-NEXT:       Type: NT_GNU_PROPERTY_TYPE_0 (property note)
+// LLVM-NEXT:       Property [
+// LLVM-NEXT:         <corrupted GNU_PROPERTY_TYPE_0>
+// LLVM-NEXT:       ]
+// LLVM-NEXT:     }
+// LLVM-NEXT:   }
+// LLVM-NEXT: ]
 
 // Section below is broken, check we report that.
 
 .section ".note.gnu.property", "a"
 .align 4 
   .long 4           /* Name length is always 4 ("GNU") */
   .long end - begin /* Data length */
   .long 5           /* Type: NT_GNU_PROPERTY_TYPE_0 */
   .asciz "GNU"      /* Name */
   .p2align 3
 begin:
   .long 1           /* Type: GNU_PROPERTY_STACK_SIZE */
 end:

tools/llvm-readobj/ELFDumper.cpp

static std::string getAMDGPUNoteTypeName(const uint32_t NT) {
 
   std::string string;
   raw_string_ostream OS(string);
   OS << format("Unknown note type (0x%08x)", NT);
   return OS.str();
 }
 
 template <typename ELFT>
-static void printGNUProperty(raw_ostream &OS, uint32_t Type, uint32_t DataSize,
+static std::string getGNUProperty(uint32_t Type, uint32_t DataSize,
                                   ArrayRef<uint8_t> Data) {
+  std::string str;
+  raw_string_ostream OS(str);
   switch (Type) {
   default:
-    OS << format("    <application-specific type 0x%x>\n", Type);
-    return;
+    OS << format("<application-specific type 0x%x>", Type);
+    return OS.str();
   case GNU_PROPERTY_STACK_SIZE: {
-    OS << "    stack size: ";
+    OS << "stack size: ";
     if (DataSize == sizeof(typename ELFT::uint))
-      OS << format("0x%llx\n",
+      OS << format("0x%llx",
                    (uint64_t)(*(const typename ELFT::Addr *)Data.data()));
     else
-      OS << format("<corrupt length: 0x%x>\n", DataSize);
-    break;
+      OS << format("<corrupt length: 0x%x>", DataSize);
+    return OS.str();
   }
   case GNU_PROPERTY_NO_COPY_ON_PROTECTED:
-    OS << "    no copy on protected";
+    OS << "no copy on protected";
     if (DataSize)
       OS << format(" <corrupt length: 0x%x>", DataSize);
-    OS << "\n";
-    break;
+    return OS.str();
   case GNU_PROPERTY_X86_FEATURE_1_AND:
-    OS << "    X86 features: ";
+    OS << "X86 features: ";
     if (DataSize != 4 && DataSize != 8) {
-      OS << format("<corrupt length: 0x%x>\n", DataSize);
-      break;
+      OS << format("<corrupt length: 0x%x>", DataSize);
+      return OS.str();
     }
     uint64_t CFProtection =
         (DataSize == 4)
             ? support::endian::read32<ELFT::TargetEndianness>(Data.data())
             : support::endian::read64<ELFT::TargetEndianness>(Data.data());
     if (CFProtection == 0) {
-      OS << "none\n";
-      break;
+      OS << "none";
+      return OS.str();
     }
     if (CFProtection & GNU_PROPERTY_X86_FEATURE_1_IBT) {
       OS << "IBT";
       CFProtection &= ~GNU_PROPERTY_X86_FEATURE_1_IBT;
       if (CFProtection)
         OS << ", ";
     }
     if (CFProtection & GNU_PROPERTY_X86_FEATURE_1_SHSTK) {
       OS << "SHSTK";
       CFProtection &= ~GNU_PROPERTY_X86_FEATURE_1_SHSTK;
       if (CFProtection)
         OS << ", ";
     }
     if (CFProtection)
       OS << format("<unknown flags: 0x%llx>", CFProtection);
-    OS << "\n";
-    break;
+    return OS.str();
   }
 }
 
 template <typename ELFT>
-static void printGNUNote(raw_ostream &OS, uint32_t NoteType,
-                         ArrayRef<typename ELFT::Word> Words, size_t Size) {
+static SmallVector<std::string, 4>
+getGNUPropertyList(ArrayRef<typename ELFT::Word> Words) {
   using Elf_Word = typename ELFT::Word;
 
-  switch (NoteType) {
-  default:
-    return;
-  case ELF::NT_GNU_ABI_TAG: {
-    static const char *OSNames[] = {
-        "Linux", "Hurd", "Solaris", "FreeBSD", "NetBSD", "Syllable", "NaCl",
-    };
-
-    StringRef OSName = "Unknown";
-    if (Words[0] < array_lengthof(OSNames))
-      OSName = OSNames[Words[0]];
-    uint32_t Major = Words[1], Minor = Words[2], Patch = Words[3];
+  SmallVector<std::string, 4> Properties;
+  ArrayRef<uint8_t> Arr(reinterpret_cast<const uint8_t *>(Words.data()),
+                        Words.size());
+  while (Arr.size() >= 8) {
+    uint32_t Type = *reinterpret_cast<const Elf_Word *>(Arr.data());
+    uint32_t DataSize = *reinterpret_cast<const Elf_Word *>(Arr.data() + 4);
+    Arr = Arr.drop_front(8);
+
+    // Take padding size into account if present.
+    uint64_t PaddedSize = alignTo(DataSize, sizeof(typename ELFT::uint));
+    std::string str;
+    raw_string_ostream OS(str);
+    if (Arr.size() < PaddedSize) {
+      OS << format("<corrupt type (0x%x) datasz: 0x%x>", Type, DataSize);
+      Properties.push_back(OS.str());
+      break;
+    }
+    Properties.push_back(
+        getGNUProperty<ELFT>(Type, DataSize, Arr.take_front(PaddedSize)));
+    Arr = Arr.drop_front(PaddedSize);
+  }
+
+  if (!Arr.empty())
+    Properties.push_back("<corrupted GNU_PROPERTY_TYPE_0>");
+
+  return Properties;
+}
+
+struct GNUAbiTag {
+  std::string OSName;
+  std::string ABI;
+  bool IsValid;
+};
+
+template <typename ELFT>
+static GNUAbiTag getGNUAbiTag(ArrayRef<typename ELFT::Word> Words) {
+  if (Words.size() < 4)
+    return {"", "", /*IsValid=*/false};
+
+  std::string str;
+  raw_string_ostream ABI(str);
+  ABI << Major << "." << Minor << "." << Patch;
+  return {OSName, ABI.str(), /*IsValid=*/true};
+}
 
-    if (Words.size() < 4)
+template <typename ELFT>
+static std::string getGNUBuildId(ArrayRef<typename ELFT::Word> Words) {
+  std::string str;
+  raw_string_ostream OS(str);
+  ArrayRef<uint8_t> ID(reinterpret_cast<const uint8_t *>(Words.data()),
+                       Words.size());
+  for (const auto &B : ID)
+    OS << format_hex_no_prefix(B, 2);
+  return OS.str();
+}
+
+template <typename ELFT>
+static StringRef getGNUGoldVersion(ArrayRef<typename ELFT::Word> Words) {
+  return StringRef(reinterpret_cast<const char *>(Words.data()), Words.size());
+}
+
+template <typename ELFT>
+static void printGNUNote(raw_ostream &OS, uint32_t NoteType,
+                         ArrayRef<typename ELFT::Word> Words) {
+  switch (NoteType) {
+  default:
+    return;
+  case ELF::NT_GNU_ABI_TAG: {
+    const GNUAbiTag &AbiTag = getGNUAbiTag<ELFT>(Words);
+    if (!AbiTag.IsValid)
       OS << "    <corrupt GNU_ABI_TAG>";
     else
-      OS << "    OS: " << OSName << ", ABI: " << Major << "." << Minor << "."
-         << Patch;
+      OS << "    OS: " << AbiTag.OSName << ", ABI: " << AbiTag.ABI;
     break;
   }
   case ELF::NT_GNU_BUILD_ID: {
-    OS << "    Build ID: ";
-    ArrayRef<uint8_t> ID(reinterpret_cast<const uint8_t *>(Words.data()), Size);
-    for (const auto &B : ID)
-      OS << format_hex_no_prefix(B, 2);
+    OS << "    Build ID: " << getGNUBuildId<ELFT>(Words);
     break;
   }
   case ELF::NT_GNU_GOLD_VERSION:
-    OS << "    Version: "
-       << StringRef(reinterpret_cast<const char *>(Words.data()), Size);
+    OS << "    Version: " << getGNUGoldVersion<ELFT>(Words);
     break;
   case ELF::NT_GNU_PROPERTY_TYPE_0:
     OS << "    Properties:";
-
-    ArrayRef<uint8_t> Arr(reinterpret_cast<const uint8_t *>(Words.data()),
-                          Size);
-    while (Arr.size() >= 8) {
-      uint32_t Type = *reinterpret_cast<const Elf_Word *>(Arr.data());
-      uint32_t DataSize = *reinterpret_cast<const Elf_Word *>(Arr.data() + 4);
-      Arr = Arr.drop_front(8);
-
-      // Take padding size into account if present.
-      uint64_t PaddedSize = alignTo(DataSize, sizeof(typename ELFT::uint));
-      if (Arr.size() < PaddedSize) {
-        OS << format("    <corrupt type (0x%x) datasz: 0x%x>\n", Type,
-                     DataSize);
-        break;
-      }
-      printGNUProperty<ELFT>(OS, Type, DataSize, Arr.take_front(PaddedSize));
-      Arr = Arr.drop_front(PaddedSize);
-    }
-
-    if (!Arr.empty())
-      OS << "    <corrupted GNU_PROPERTY_TYPE_0>";
+    for (const auto &Property : getGNUPropertyList<ELFT>(Words))
+      OS << "    " << Property << "\n";
     break;
   }
   OS << '\n';
 }
 
+struct AMDGPUNote {
+  std::string type;
+  std::string value;
+};
+
 template <typename ELFT>
-static void printAMDGPUNote(raw_ostream &OS, uint32_t NoteType,
-                            ArrayRef<typename ELFT::Word> Words, size_t Size) {
+static AMDGPUNote getAMDGPUNote(uint32_t NoteType,
+                                ArrayRef<typename ELFT::Word> Words) {
   switch (NoteType) {
   default:
-    return;
-    case ELF::NT_AMD_AMDGPU_HSA_METADATA:
-      OS << "    HSA Metadata:\n"
-         << StringRef(reinterpret_cast<const char *>(Words.data()), Size);
-      break;
-    case ELF::NT_AMD_AMDGPU_ISA:
-      OS << "    ISA Version:\n"
-         << "        "
-         << StringRef(reinterpret_cast<const char *>(Words.data()), Size);
-      break;
-    case ELF::NT_AMD_AMDGPU_PAL_METADATA:
-      const uint32_t *PALMetadataBegin = reinterpret_cast<const uint32_t *>(Words.data());
-      const uint32_t *PALMetadataEnd = PALMetadataBegin + Size;
-      std::vector<uint32_t> PALMetadata(PALMetadataBegin, PALMetadataEnd);
-      std::string PALMetadataString;
-      auto Error = AMDGPU::PALMD::toString(PALMetadata, PALMetadataString);
-      OS << "    PAL Metadata:\n";
-      if (Error) {
-        OS << "        Invalid";
-        return;
-      }
-      OS << PALMetadataString;
-      break;
+    return {"", ""};
+    return {"HSA Metadata",
+            std::string(reinterpret_cast<const char *>(Words.data()),
+                        Words.size())};
+    return {"ISA Version",
+            std::string(reinterpret_cast<const char *>(Words.data()),
+                        Words.size())};
+    const uint32_t *PALMetadataBegin =
+        reinterpret_cast<const uint32_t *>(Words.data());
+    const uint32_t *PALMetadataEnd = PALMetadataBegin + Words.size();
+      return {"PAL Metadata", "Invalid"};
+    return {"PAL Metadata", PALMetadataString};
   }
-  OS.flush();
 }
 
 template <class ELFT>
 void GNUStyle<ELFT>::printNotes(const ELFFile<ELFT> *Obj) {
   const Elf_Ehdr *e = Obj->getHeader();
   bool IsCore = e->e_type == ELF::ET_CORE;
 
   auto PrintHeader = [&](const typename ELFT::Off Offset,
                          const typename ELFT::Addr Size) {
     OS << "Displaying notes found at file offset " << format_hex(Offset, 10)
        << " with length " << format_hex(Size, 10) << ":\n"
        << "  Owner                 Data size\tDescription\n";
   };
 
   auto ProcessNote = [&](const Elf_Note &Note) {
     StringRef Name = Note.getName();
     ArrayRef<Elf_Word> Descriptor = Note.getDesc();
     Elf_Word Type = Note.getType();
 
     OS << "  " << Name << std::string(22 - Name.size(), ' ')
        << format_hex(Descriptor.size(), 10) << '\t';
 
     if (Name == "GNU") {
       OS << getGNUNoteTypeName(Type) << '\n';
-      printGNUNote<ELFT>(OS, Type, Descriptor, Descriptor.size());
+      printGNUNote<ELFT>(OS, Type, Descriptor);
     } else if (Name == "FreeBSD") {
       OS << getFreeBSDNoteTypeName(Type) << '\n';
     } else if (Name == "AMD") {
       OS << getAMDGPUNoteTypeName(Type) << '\n';
-      printAMDGPUNote<ELFT>(OS, Type, Descriptor, Descriptor.size());
+      const AMDGPUNote N = getAMDGPUNote<ELFT>(Type, Descriptor);
+      if (!N.type.empty())
+        OS << "    " << N.type << ":\n        " << N.value << '\n';
     } else {
       OS << "Unknown note type: (" << format_hex(Type, 10) << ')';
     }
     OS << '\n';
   };
 
   if (IsCore) {
     for (const auto &P : unwrapOrError(Obj->program_headers())) {
while (Cur != End) {
     if (Err)
       reportError(Err);
     W.printNumber("Sym", this->dumper()->getStaticSymbolName(SymIndex),
                   SymIndex);
     Cur += Size;
   }
 }
 
+template <typename ELFT>
+static void printGNUNoteLLVMStyle(uint32_t NoteType,
+                                  ArrayRef<typename ELFT::Word> Words,
+                                  ScopedPrinter &W) {
+  switch (NoteType) {
+  default:
+    return;
+  case ELF::NT_GNU_ABI_TAG: {
+    const GNUAbiTag &AbiTag = getGNUAbiTag<ELFT>(Words);
+    if (!AbiTag.IsValid) {
+      W.printString("ABI", "<corrupt GNU_ABI_TAG>");
+    } else {
+      W.printString("OS", AbiTag.OSName);
+      W.printString("ABI", AbiTag.ABI);
+    }
+    break;
+  }
+  case ELF::NT_GNU_BUILD_ID: {
+    W.printString("Build ID", getGNUBuildId<ELFT>(Words));
+    break;
+  }
+  case ELF::NT_GNU_GOLD_VERSION:
+    W.printString("Version", getGNUGoldVersion<ELFT>(Words));
+    break;
+  case ELF::NT_GNU_PROPERTY_TYPE_0:
+    ListScope D(W, "Property");
+    for (const auto &Property : getGNUPropertyList<ELFT>(Words))
+      W.printString(Property);
+    break;
+  }
+}
+
 template <class ELFT>
 void LLVMStyle<ELFT>::printNotes(const ELFFile<ELFT> *Obj) {
-  W.startLine() << "printNotes not implemented!\n";
+  ListScope L(W, "Notes");
+  const Elf_Ehdr *e = Obj->getHeader();
+  bool IsCore = e->e_type == ELF::ET_CORE;
+
+  auto PrintHeader = [&](const typename ELFT::Off Offset,
+                         const typename ELFT::Addr Size) {
+    W.printHex("Offset", Offset);
+    W.printHex("Size", Size);
+  };
+
+  auto ProcessNote = [&](const Elf_Note &Note) {
+    DictScope D2(W, "Note");
+    StringRef Name = Note.getName();
+    ArrayRef<Elf_Word> Descriptor = Note.getDesc();
+    Elf_Word Type = Note.getType();
+
+    W.printString("Owner", Name);
+    W.printHex("Data size", Descriptor.size());
+    if (Name == "GNU") {
+      W.printString("Type", getGNUNoteTypeName(Type));
+      printGNUNoteLLVMStyle<ELFT>(Type, Descriptor, W);
+    } else if (Name == "FreeBSD") {
+      W.printString("Type", getFreeBSDNoteTypeName(Type));
+    } else if (Name == "AMD") {
+      W.printString("Type", getAMDGPUNoteTypeName(Type));
+      const AMDGPUNote N = getAMDGPUNote<ELFT>(Type, Descriptor);
+      if (!N.type.empty())
+        W.printString(N.type, N.value);
+    } else {
+      W.getOStream() << "Unknown note type: (" << format_hex(Type, 10) << ')';
+    }
+  };
+
+  if (IsCore) {
+    for (const auto &P : unwrapOrError(Obj->program_headers())) {
+      if (P.p_type != PT_NOTE)
+        continue;
+      DictScope D(W, "NoteSection");
+      PrintHeader(P.p_offset, P.p_filesz);
+      Error Err = Error::success();
+      for (const auto &Note : Obj->notes(P, Err))
+        ProcessNote(Note);
+      if (Err)
+        error(std::move(Err));
+    }
+  } else {
+    for (const auto &S : unwrapOrError(Obj->sections())) {
+      if (S.sh_type != SHT_NOTE)
+        continue;
+      DictScope D(W, "NoteSection");
+      PrintHeader(S.sh_offset, S.sh_size);
+      Error Err = Error::success();
+      for (const auto &Note : Obj->notes(S, Err))
+        ProcessNote(Note);
+      if (Err)
+        error(std::move(Err));
+    }
+  }
 }
 
 template <class ELFT>
 void LLVMStyle<ELFT>::printELFLinkerOptions(const ELFFile<ELFT> *Obj) {
   ListScope L(W, "LinkerOptions");
 
   for (const Elf_Shdr &Shdr : unwrapOrError(Obj->sections())) {
     if (Shdr.sh_type != ELF::SHT_LLVM_LINKER_OPTIONS)