Reapply "[llvm-objcopy][ELF] Add an option to remove notes (#118739)"

This fixes "unused-local-typedef" warnings in 9324e6a7a5.

This adds an option `--remove-note=[name/]type` to selectively delete
notes in ELF files, where `type` is the numeric value of the note type
and `name` is the name of the originator. The name can be omitted, in
which case all notes of the specified type will be removed. For now,
only `SHT_NOTE` sections that are not associated with segments are
handled. The implementation can be extended later as needed.

RFC: https://discourse.llvm.org/t/rfc-llvm-objcopy-feature-for-editing-notes/83491

10 files changed, 423 insertions, 16 deletions

diff --git a/llvm/docs/CommandGuide/llvm-objcopy.rst b/llvm/docs/CommandGuide/llvm-objcopy.rst
index be4876c..8dc1357 100644
--- a/llvm/docs/CommandGuide/llvm-objcopy.rst
+++ b/llvm/docs/CommandGuide/llvm-objcopy.rst
@@ -477,6 +477,11 @@ them.
 
  Preserve access and modification timestamps in the output.
 
+.. option:: --remove-note [<name>/]<type>
+
+ Remove notes of integer type ``<type>`` and name ``<name>`` from SHT_NOTE
+ sections that are not in a segment. Can be specified multiple times.
+
 .. option:: --rename-section <old>=<new>[,<flag>,...]
 
  Rename sections called ``<old>`` to ``<new>`` in the output, and apply any
diff --git a/llvm/include/llvm/ObjCopy/CommonConfig.h b/llvm/include/llvm/ObjCopy/CommonConfig.h
index 5ae0976..aea9cd6 100644
--- a/llvm/include/llvm/ObjCopy/CommonConfig.h
+++ b/llvm/include/llvm/ObjCopy/CommonConfig.h
@@ -281,6 +281,11 @@ struct CommonConfig {
 
   SmallVector<std::pair<NameMatcher, llvm::DebugCompressionType>, 0>
       compressSections;
+
+  // ErrorCallback is used to handle recoverable errors. An Error returned
+  // by the callback aborts the execution and is then returned to the caller.
+  // If the callback is not set, the errors are not issued.
+  std::function<Error(Error)> ErrorCallback;
 };
 
 } // namespace objcopy
diff --git a/llvm/include/llvm/ObjCopy/ELF/ELFConfig.h b/llvm/include/llvm/ObjCopy/ELF/ELFConfig.h
index 59960b6..01a8762 100644
--- a/llvm/include/llvm/ObjCopy/ELF/ELFConfig.h
+++ b/llvm/include/llvm/ObjCopy/ELF/ELFConfig.h
@@ -15,6 +15,12 @@
 namespace llvm {
 namespace objcopy {
 
+// Note to remove info specified by --remove-note option.
+struct RemoveNoteInfo {
+  StringRef Name;
+  uint32_t TypeId;
+};
+
 // ELF specific configuration for copying/stripping a single file.
 struct ELFConfig {
   uint8_t NewSymbolVisibility = (uint8_t)ELF::STV_DEFAULT;
@@ -31,6 +37,9 @@ struct ELFConfig {
   bool KeepFileSymbols = false;
   bool LocalizeHidden = false;
   bool VerifyNoteSections = true;
+
+  // Notes specified by --remove-note option.
+  SmallVector<RemoveNoteInfo, 0> NotesToRemove;
 };
 
 } // namespace objcopy
diff --git a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
index 4793651..5aa0079 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
+++ b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
@@ -609,6 +609,113 @@ static void addSymbol(Object &Obj, const NewSymbolInfo &SymInfo,
       Sec ? (uint16_t)SYMBOL_SIMPLE_INDEX : (uint16_t)SHN_ABS, 0);
 }
 
+namespace {
+struct RemoveNoteDetail {
+  struct DeletedRange {
+    uint64_t OldFrom;
+    uint64_t OldTo;
+  };
+
+  template <class ELFT>
+  static std::vector<DeletedRange>
+  findNotesToRemove(ArrayRef<uint8_t> Data, size_t Align,
+                    ArrayRef<RemoveNoteInfo> NotesToRemove);
+  static std::vector<uint8_t> updateData(ArrayRef<uint8_t> OldData,
+                                         ArrayRef<DeletedRange> ToRemove);
+};
+} // namespace
+
+template <class ELFT>
+std::vector<RemoveNoteDetail::DeletedRange>
+RemoveNoteDetail::findNotesToRemove(ArrayRef<uint8_t> Data, size_t Align,
+                                    ArrayRef<RemoveNoteInfo> NotesToRemove) {
+  using Elf_Nhdr = typename ELFT::Nhdr;
+  using Elf_Note = typename ELFT::Note;
+  std::vector<DeletedRange> ToRemove;
+  uint64_t CurPos = 0;
+  while (CurPos + sizeof(Elf_Nhdr) <= Data.size()) {
+    auto Nhdr = reinterpret_cast<const Elf_Nhdr *>(Data.data() + CurPos);
+    size_t FullSize = Nhdr->getSize(Align);
+    if (CurPos + FullSize > Data.size())
+      break;
+    Elf_Note Note(*Nhdr);
+    bool ShouldRemove =
+        llvm::any_of(NotesToRemove, [&Note](const RemoveNoteInfo &NoteInfo) {
+          return NoteInfo.TypeId == Note.getType() &&
+                 (NoteInfo.Name.empty() || NoteInfo.Name == Note.getName());
+        });
+    if (ShouldRemove)
+      ToRemove.push_back({CurPos, CurPos + FullSize});
+    CurPos += FullSize;
+  }
+  return ToRemove;
+}
+
+std::vector<uint8_t>
+RemoveNoteDetail::updateData(ArrayRef<uint8_t> OldData,
+                             ArrayRef<DeletedRange> ToRemove) {
+  std::vector<uint8_t> NewData;
+  NewData.reserve(OldData.size());
+  uint64_t CurPos = 0;
+  for (const DeletedRange &RemRange : ToRemove) {
+    if (CurPos < RemRange.OldFrom) {
+      auto Slice = OldData.slice(CurPos, RemRange.OldFrom - CurPos);
+      NewData.insert(NewData.end(), Slice.begin(), Slice.end());
+    }
+    CurPos = RemRange.OldTo;
+  }
+  if (CurPos < OldData.size()) {
+    auto Slice = OldData.slice(CurPos);
+    NewData.insert(NewData.end(), Slice.begin(), Slice.end());
+  }
+  return NewData;
+}
+
+static Error removeNotes(Object &Obj, endianness Endianness,
+                         ArrayRef<RemoveNoteInfo> NotesToRemove,
+                         function_ref<Error(Error)> ErrorCallback) {
+  // TODO: Support note segments.
+  if (ErrorCallback) {
+    for (Segment &Seg : Obj.segments()) {
+      if (Seg.Type == PT_NOTE) {
+        if (Error E = ErrorCallback(createStringError(
+                errc::not_supported, "note segments are not supported")))
+          return E;
+        break;
+      }
+    }
+  }
+  for (auto &Sec : Obj.sections()) {
+    if (Sec.Type != SHT_NOTE || !Sec.hasContents())
+      continue;
+    // TODO: Support note sections in segments.
+    if (Sec.ParentSegment) {
+      if (ErrorCallback)
+        if (Error E = ErrorCallback(createStringError(
+                errc::not_supported,
+                "cannot remove note(s) from " + Sec.Name +
+                    ": sections in segments are not supported")))
+          return E;
+      continue;
+    }
+    ArrayRef<uint8_t> OldData = Sec.getContents();
+    size_t Align = std::max<size_t>(4, Sec.Align);
+    // Note: notes for both 32-bit and 64-bit ELF files use 4-byte words in the
+    // header, so the parsers are the same.
+    auto ToRemove = (Endianness == endianness::little)
+                        ? RemoveNoteDetail::findNotesToRemove<ELF64LE>(
+                              OldData, Align, NotesToRemove)
+                        : RemoveNoteDetail::findNotesToRemove<ELF64BE>(
+                              OldData, Align, NotesToRemove);
+    if (!ToRemove.empty()) {
+      if (Error E = Obj.updateSectionData(
+              Sec, RemoveNoteDetail::updateData(OldData, ToRemove)))
+        return E;
+    }
+  }
+  return Error::success();
+}
+
 static Error
 handleUserSection(const NewSectionInfo &NewSection,
                   function_ref<Error(StringRef, ArrayRef<uint8_t>)> F) {
@@ -799,6 +906,12 @@ static Error handleArgs(const CommonConfig &Config, const ELFConfig &ELFConfig,
                      ? endianness::little
                      : endianness::big;
 
+  if (!ELFConfig.NotesToRemove.empty()) {
+    if (Error Err =
+            removeNotes(Obj, E, ELFConfig.NotesToRemove, Config.ErrorCallback))
+      return Err;
+  }
+
   for (const NewSectionInfo &AddedSection : Config.AddSection) {
     auto AddSection = [&](StringRef Name, ArrayRef<uint8_t> Data) -> Error {
       OwnedDataSection &NewSection =
diff --git a/llvm/lib/ObjCopy/ELF/ELFObject.cpp b/llvm/lib/ObjCopy/ELF/ELFObject.cpp
index 01c2f24..45c7ea4 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObject.cpp
+++ b/llvm/lib/ObjCopy/ELF/ELFObject.cpp
@@ -2154,37 +2154,46 @@ ELFWriter<ELFT>::ELFWriter(Object &Obj, raw_ostream &Buf, bool WSH,
     : Writer(Obj, Buf), WriteSectionHeaders(WSH && Obj.HadShdrs),
       OnlyKeepDebug(OnlyKeepDebug) {}
 
-Error Object::updateSection(StringRef Name, ArrayRef<uint8_t> Data) {
-  auto It = llvm::find_if(Sections,
-                          [&](const SecPtr &Sec) { return Sec->Name == Name; });
-  if (It == Sections.end())
-    return createStringError(errc::invalid_argument, "section '%s' not found",
-                             Name.str().c_str());
-
-  auto *OldSec = It->get();
-  if (!OldSec->hasContents())
+Error Object::updateSectionData(SecPtr &Sec, ArrayRef<uint8_t> Data) {
+  if (!Sec->hasContents())
     return createStringError(
         errc::invalid_argument,
         "section '%s' cannot be updated because it does not have contents",
-        Name.str().c_str());
+        Sec->Name.c_str());
 
-  if (Data.size() > OldSec->Size && OldSec->ParentSegment)
+  if (Data.size() > Sec->Size && Sec->ParentSegment)
     return createStringError(errc::invalid_argument,
                              "cannot fit data of size %zu into section '%s' "
                              "with size %" PRIu64 " that is part of a segment",
-                             Data.size(), Name.str().c_str(), OldSec->Size);
+                             Data.size(), Sec->Name.c_str(), Sec->Size);
 
-  if (!OldSec->ParentSegment) {
-    *It = std::make_unique<OwnedDataSection>(*OldSec, Data);
+  if (!Sec->ParentSegment) {
+    Sec = std::make_unique<OwnedDataSection>(*Sec, Data);
   } else {
     // The segment writer will be in charge of updating these contents.
-    OldSec->Size = Data.size();
-    UpdatedSections[OldSec] = Data;
+    Sec->Size = Data.size();
+    UpdatedSections[Sec.get()] = Data;
   }
 
   return Error::success();
 }
 
+Error Object::updateSection(StringRef Name, ArrayRef<uint8_t> Data) {
+  auto It = llvm::find_if(Sections,
+                          [&](const SecPtr &Sec) { return Sec->Name == Name; });
+  if (It == Sections.end())
+    return createStringError(errc::invalid_argument, "section '%s' not found",
+                             Name.str().c_str());
+  return updateSectionData(*It, Data);
+}
+
+Error Object::updateSectionData(SectionBase &S, ArrayRef<uint8_t> Data) {
+  auto It = llvm::find_if(Sections,
+                          [&](const SecPtr &Sec) { return Sec.get() == &S; });
+  assert(It != Sections.end() && "The section should belong to the object");
+  return updateSectionData(*It, Data);
+}
+
 Error Object::removeSections(
     bool AllowBrokenLinks, std::function<bool(const SectionBase &)> ToRemove) {
 
diff --git a/llvm/lib/ObjCopy/ELF/ELFObject.h b/llvm/lib/ObjCopy/ELF/ELFObject.h
index 6ccf853..d8f79a4 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObject.h
+++ b/llvm/lib/ObjCopy/ELF/ELFObject.h
@@ -549,6 +549,7 @@ public:
   virtual void
   replaceSectionReferences(const DenseMap<SectionBase *, SectionBase *> &);
   virtual bool hasContents() const { return false; }
+  virtual ArrayRef<uint8_t> getContents() const { return {}; }
   // Notify the section that it is subject to removal.
   virtual void onRemove();
 
@@ -619,6 +620,8 @@ public:
   bool hasContents() const override {
     return Type != ELF::SHT_NOBITS && Type != ELF::SHT_NULL;
   }
+  ArrayRef<uint8_t> getContents() const override { return Contents; }
+
   void restoreSymTabLink(SymbolTableSection &SymTab) override;
 };
 
@@ -654,6 +657,7 @@ public:
   Error accept(SectionVisitor &Sec) const override;
   Error accept(MutableSectionVisitor &Visitor) override;
   bool hasContents() const override { return true; }
+  ArrayRef<uint8_t> getContents() const override { return Data; }
 };
 
 class CompressedSection : public SectionBase {
@@ -1164,6 +1168,8 @@ private:
     return Sec.Flags & ELF::SHF_ALLOC;
   };
 
+  Error updateSectionData(SecPtr &Sec, ArrayRef<uint8_t> Data);
+
 public:
   template <class T>
   using ConstRange = iterator_range<pointee_iterator<
@@ -1206,6 +1212,7 @@ public:
 
   const auto &getUpdatedSections() const { return UpdatedSections; }
   Error updateSection(StringRef Name, ArrayRef<uint8_t> Data);
+  Error updateSectionData(SectionBase &S, ArrayRef<uint8_t> Data);
 
   SectionBase *findSection(StringRef Name) {
     auto SecIt =
diff --git a/llvm/test/tools/llvm-objcopy/ELF/remove-note.test b/llvm/test/tools/llvm-objcopy/ELF/remove-note.test
new file mode 100644
index 0000000..f8936bf
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/ELF/remove-note.test
@@ -0,0 +1,198 @@
+## Check incompatible options.

+# RUN: not llvm-objcopy --remove-note=1 --remove-section=.test - 2>&1 | FileCheck %s --check-prefix=ERR-REMSEC

+# RUN: not llvm-objcopy --remove-note=1 --add-section=.test=%s - 2>&1 | FileCheck %s --check-prefix=ERR-ADDSEC

+# RUN: not llvm-objcopy --remove-note=1 --update-section=.test=%s - 2>&1 | FileCheck %s --check-prefix=ERR-UPDSEC

+

+# ERR-REMSEC: error: cannot specify both --remove-note and --remove-section

+# ERR-ADDSEC: error: cannot specify both --remove-note and --add-section

+# ERR-UPDSEC: error: cannot specify both --remove-note and --update-section

+

+## Check invalid argument formats.

+# RUN: not llvm-objcopy --remove-note= - 2>&1 | FileCheck %s --check-prefix=ERR-NOTYPEID

+# RUN: not llvm-objcopy --remove-note=CORE/ - 2>&1 | FileCheck %s --check-prefix=ERR-NOTYPEID

+# RUN: not llvm-objcopy --remove-note=/1 - 2>&1 | FileCheck %s --check-prefix=ERR-EMPTYNAME

+# RUN: not llvm-objcopy --remove-note=CORE/1/2 - 2>&1 | FileCheck %s --check-prefix=ERR-INVNUM1

+# RUN: not llvm-objcopy --remove-note=Notanumber - 2>&1 | FileCheck %s --check-prefix=ERR-INVNUM2

+# RUN: not llvm-objcopy --remove-note=CORE/Notanumber - 2>&1 | FileCheck %s --check-prefix=ERR-INVNUM2

+

+# ERR-NOTYPEID: error: bad format for --remove-note, missing type_id

+# ERR-EMPTYNAME: error: bad format for --remove-note, note name is empty

+# ERR-INVNUM1: error: bad note type_id for --remove-note: '1/2'

+# ERR-INVNUM2: error: bad note type_id for --remove-note: 'Notanumber'

+

+## Check deleting notes:

+## * --remove-note=1 will remove note "CORE/1" and "LINUX/1",

+## * --remove-note=DUMMY/2 will not remove any notes because there are no notes with this owner,

+## * --remove-note=CORE/3 will remove "CORE/3" but preserve "LINUX/3".

+# RUN: yaml2obj --docnum=1 -D ALIGN=8 -D ELFCLASS=64 -D ENDIANNESS=LSB %s -o %t8.64.lsb

+# RUN: llvm-objcopy --remove-note=0x01 --remove-note=DUMMY/2 --remove-note=CORE/0x03 %t8.64.lsb %t8.64.lsb.o

+# RUN: llvm-readobj --segments --sections --notes %t8.64.lsb.o | \

+# RUN:   FileCheck %s -D#SIZE0=32 -D#SIZE1=64

+

+# RUN: yaml2obj --docnum=1 -D ALIGN=4 -D ELFCLASS=64 -D ENDIANNESS=MSB %s -o %t4.64.msb

+# RUN: llvm-objcopy --remove-note=0x01 --remove-note=DUMMY/0x02 --remove-note=CORE/3 %t4.64.msb %t4.64.msb.o

+# RUN: llvm-readobj --segments --sections --notes %t4.64.msb.o | \

+# RUN:   FileCheck %s -D#SIZE0=24 -D#SIZE1=48

+

+# RUN: yaml2obj --docnum=1 -D ALIGN=4 -D ELFCLASS=32 -D ENDIANNESS=LSB %s -o %t4.32.lsb

+# RUN: llvm-objcopy --remove-note=1 --remove-note=DUMMY/0x02 --remove-note=CORE/3 %t4.32.lsb %t4.32.lsb.o

+# RUN: llvm-readobj --segments --sections --notes %t4.32.lsb.o | \

+# RUN:   FileCheck %s -D#SIZE0=24 -D#SIZE1=48

+

+# CHECK:      Sections [

+# CHECK:        Section {

+# CHECK:          Name: .note0

+# CHECK-NEXT:     Type: SHT_NOTE

+# CHECK-NEXT:     Flags [

+# CHECK-NEXT:     ]

+# CHECK-NEXT:     Address:

+# CHECK-NEXT:     Offset:

+# CHECK-NEXT:     Size: [[#%d,SIZE0]]

+# CHECK:          Name: .note1

+# CHECK-NEXT:     Type: SHT_NOTE

+# CHECK-NEXT:     Flags [

+# CHECK-NEXT:     ]

+# CHECK-NEXT:     Address:

+# CHECK-NEXT:     Offset:

+# CHECK-NEXT:     Size: [[#%d,SIZE1]]

+# CHECK:          Name: .note2

+# CHECK-NEXT:     Type: SHT_NOTE

+# CHECK-NEXT:     Flags [

+# CHECK-NEXT:     ]

+# CHECK-NEXT:     Address:

+# CHECK-NEXT:     Offset:

+# CHECK-NEXT:     Size: 0

+

+# CHECK:      NoteSections [

+# CHECK-NEXT:   NoteSection {

+# CHECK-NEXT:     Name: .note0

+# CHECK-NEXT:     Offset:

+# CHECK-NEXT:     Size: 0x[[#%X,SIZE0]]

+# CHECK-NEXT:     Notes [

+# CHECK-NEXT:       {

+# CHECK-NEXT:         Owner: CORE

+# CHECK-NEXT:         Data size: 0x2

+# CHECK-NEXT:         Type: NT_ARCH

+# CHECK-NEXT:         Description data (

+# CHECK-NEXT:           0000: 0201

+# CHECK-NEXT:         )

+# CHECK-NEXT:       }

+# CHECK-NEXT:     ]

+# CHECK-NEXT:   }

+# CHECK-NEXT:   NoteSection {

+# CHECK-NEXT:     Name: .note1

+# CHECK-NEXT:     Offset:

+# CHECK-NEXT:     Size: 0x[[#%X,SIZE1]]

+# CHECK-NEXT:     Notes [

+# CHECK-NEXT:       {

+# CHECK-NEXT:         Owner: LINUX

+# CHECK-NEXT:         Data size: 0x2

+# CHECK-NEXT:         Type: Unknown (0x00000003)

+# CHECK-NEXT:         Description data (

+# CHECK-NEXT:           0000: 0301

+# CHECK-NEXT:         )

+# CHECK-NEXT:       }

+# CHECK-NEXT:       {

+# CHECK-NEXT:         Owner: CORE

+# CHECK-NEXT:         Data size: 0x2

+# CHECK-NEXT:         Type: Unknown (0x00000004)

+# CHECK-NEXT:         Description data (

+# CHECK-NEXT:           0000: 0401

+# CHECK-NEXT:         )

+# CHECK-NEXT:       }

+# CHECK-NEXT:     ]

+# CHECK-NEXT:   }

+# CHECK-NEXT:   NoteSection {

+# CHECK-NEXT:     Name: .note2

+# CHECK-NEXT:     Offset:

+# CHECK-NEXT:     Size: 0x0

+# CHECK-NEXT:     Notes [

+# CHECK-NEXT:     ]

+# CHECK-NEXT:   }

+

+--- !ELF

+FileHeader:

+  Class:          ELFCLASS[[ELFCLASS]]

+  Data:           ELFDATA2[[ENDIANNESS]]

+  Type:           ET_REL

+  Machine:        EM_X86_64

+Sections:

+  - Name:         .note0

+    Type:         SHT_NOTE

+    AddressAlign: [[ALIGN]]

+    Notes:

+      - Name:   CORE

+        Type:   0x01

+        Desc:   0101

+      - Name:   CORE

+        Type:   0x02

+        Desc:   0201

+  - Name:         .note1

+    Type:         SHT_NOTE

+    AddressAlign: [[ALIGN]]

+    Notes:

+      - Name:   LINUX

+        Type:   0x03

+        Desc:   0301

+      - Name:   CORE

+        Type:   0x03

+        Desc:   0302

+      - Name:   CORE

+        Type:   0x04

+        Desc:   0401

+  - Name:         .note2

+    Type:         SHT_NOTE

+    AddressAlign: [[ALIGN]]

+    Notes:

+      - Name:   LINUX

+        Type:   0x01

+        Desc:   0102

+

+# RUN: yaml2obj --docnum=2 %s -o %t2

+# RUN: llvm-objcopy --remove-note=1 %t2 %t2o 2>&1 | FileCheck %s --check-prefix=TEST2

+# TEST2: warning: note segments are not supported

+# TEST2-NOT: note segments are not supported

+

+--- !ELF

+FileHeader:

+  Class:          ELFCLASS64

+  Data:           ELFDATA2LSB

+  Type:           ET_CORE

+  Machine:        EM_X86_64

+ProgramHeaders:

+  - Type:         PT_NOTE

+    FirstSec:     .data0

+    LastSec:      .data0

+  - Type:         PT_NOTE

+    FirstSec:     .data1

+    LastSec:      .data1

+Sections:

+  - Name:         .data0

+    Type:         Fill

+    Size:         8

+  - Name:         .data1

+    Type:         Fill

+    Size:         8

+

+# RUN: yaml2obj --docnum=3 %s -o %t3

+# RUN: llvm-objcopy --remove-note=1 %t3 %t3o 2>&1 | FileCheck %s --check-prefix=TEST3

+# TEST3: warning: cannot remove note(s) from .note: sections in segments are not supported

+

+--- !ELF

+FileHeader:

+  Class:          ELFCLASS64

+  Data:           ELFDATA2LSB

+  Type:           ET_EXEC

+  Machine:        EM_X86_64

+ProgramHeaders:

+  - Type:         PT_LOAD

+    FirstSec:     .note

+    LastSec:      .note

+Sections:

+  - Name:         .note

+    Type:         SHT_NOTE

+    AddressAlign: 4

+    Notes:

+      - Name:     ABC

+        Type:     1

+        Desc:     0102

diff --git a/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp b/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp
index 0925fc5..0d20959 100644
--- a/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp
+++ b/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp
@@ -538,6 +538,38 @@ static Expected<NewSymbolInfo> parseNewSymbolInfo(StringRef FlagValue) {
   return SI;
 }
 
+static Expected<RemoveNoteInfo> parseRemoveNoteInfo(StringRef FlagValue) {
+  // Parse value given with --remove-note option. The format is:
+  //
+  // [name/]type_id
+  //
+  // where:
+  // <name>    - optional note name. If not given, all notes with the specified
+  //             <type_id> are removed.
+  // <type_id> - note type value, can be decimal or hexadecimal number prefixed
+  //             with 0x.
+  RemoveNoteInfo NI;
+  StringRef TypeIdStr;
+  if (auto Idx = FlagValue.find('/'); Idx != StringRef::npos) {
+    if (Idx == 0)
+      return createStringError(
+          errc::invalid_argument,
+          "bad format for --remove-note, note name is empty");
+    NI.Name = FlagValue.slice(0, Idx);
+    TypeIdStr = FlagValue.substr(Idx + 1);
+  } else {
+    TypeIdStr = FlagValue;
+  }
+  if (TypeIdStr.empty())
+    return createStringError(errc::invalid_argument,
+                             "bad format for --remove-note, missing type_id");
+  if (TypeIdStr.getAsInteger(0, NI.TypeId))
+    return createStringError(errc::invalid_argument,
+                             "bad note type_id for --remove-note: '%s'",
+                             TypeIdStr.str().c_str());
+  return NI;
+}
+
 // Parse input option \p ArgValue and load section data. This function
 // extracts section name and name of the file keeping section data from
 // ArgValue, loads data from the file, and stores section name and data
@@ -1221,6 +1253,29 @@ objcopy::parseObjcopyOptions(ArrayRef<const char *> ArgsArr,
       };
     }
 
+  for (auto *Arg : InputArgs.filtered(OBJCOPY_remove_note)) {
+    Expected<RemoveNoteInfo> NoteInfo = parseRemoveNoteInfo(Arg->getValue());
+    if (!NoteInfo)
+      return NoteInfo.takeError();
+
+    ELFConfig.NotesToRemove.push_back(*NoteInfo);
+  }
+
+  if (!ELFConfig.NotesToRemove.empty()) {
+    if (!Config.ToRemove.empty())
+      return createStringError(
+          errc::invalid_argument,
+          "cannot specify both --remove-note and --remove-section");
+    if (!Config.AddSection.empty())
+      return createStringError(
+          errc::invalid_argument,
+          "cannot specify both --remove-note and --add-section");
+    if (!Config.UpdateSection.empty())
+      return createStringError(
+          errc::invalid_argument,
+          "cannot specify both --remove-note and --update-section");
+  }
+
   if (Config.DecompressDebugSections &&
       Config.CompressionType != DebugCompressionType::None) {
     return createStringError(
diff --git a/llvm/tools/llvm-objcopy/ObjcopyOpts.td b/llvm/tools/llvm-objcopy/ObjcopyOpts.td
index 434b5ff..fbc6a59 100644
--- a/llvm/tools/llvm-objcopy/ObjcopyOpts.td
+++ b/llvm/tools/llvm-objcopy/ObjcopyOpts.td
@@ -297,3 +297,7 @@ defm pad_to
                    "of zero or the value specified by the --gap-fill option. "
                    "This option is only supported for ELF input and binary output">,
       MetaVarName<"address">;
+
+defm remove_note
+    : Eq<"remove-note", "Remove note(s) with <type_id> and optional <name>">,
+      MetaVarName<"[name/]type_id">;
diff --git a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
index ad3e604..7e708e3 100644
--- a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
+++ b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
@@ -248,6 +248,8 @@ int llvm_objcopy_main(int argc, char **argv, const llvm::ToolContext &) {
     return 1;
   }
   for (ConfigManager &ConfigMgr : DriverConfig->CopyConfigs) {
+    assert(!ConfigMgr.Common.ErrorCallback);
+    ConfigMgr.Common.ErrorCallback = reportWarning;
     if (Error E = executeObjcopy(ConfigMgr)) {
       logAllUnhandledErrors(std::move(E), WithColor::error(errs(), ToolName));
       return 1;