Print a warning for note segments and note sections in segments v2

Author: igorkudrin

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

llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp

@@ -671,11 +671,32 @@ RemoveNoteDetail::updateData(ArrayRef<uint8_t> OldData,
 }
 
 static Error removeNotes(Object &Obj, endianness Endianness,
-                         ArrayRef<RemoveNoteInfo> NotesToRemove) {
+                         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()) {
-    // TODO: Support note sections in segments
-    if (Sec.Type != SHT_NOTE || Sec.ParentSegment || !Sec.hasContents())
+    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
@@ -885,7 +906,8 @@ static Error handleArgs(const CommonConfig &Config, const ELFConfig &ELFConfig,
                      : endianness::big;
 
   if (!ELFConfig.NotesToRemove.empty()) {
-    if (Error Err = removeNotes(Obj, E, ELFConfig.NotesToRemove))
+    if (Error Err =
+            removeNotes(Obj, E, ELFConfig.NotesToRemove, Config.ErrorCallback))
       return Err;
   }
 

llvm/test/tools/llvm-objcopy/ELF/remove-note-unsupported.test

@@ -0,0 +1,47 @@
+# RUN: yaml2obj --docnum=1 %s -o %t1
+# RUN: llvm-objcopy --remove-note=1 %t1 %t1o 2>&1 | FileCheck %s --check-prefix=NOTE_SEGMENT
+# NOTE_SEGMENT: warning: note segments are not supported
+# NOTE_SEGMENT-NOT: note segments are not supported
+
+--- !ELF
+FileHeader:
+  Class:          ELFCLASS64
+  Data:           ELFDATA2LSB
+  Type:           ET_EXEC
+  Machine:        EM_X86_64
+ProgramHeaders:
+  - Type:         PT_NOTE
+    FirstSec:     .data0
+    LastSec:      .data0
+  - Type:         PT_NOTE
+    FirstSec:     .data1
+    LastSec:      .data1
+Sections:
+  - Name:         .data0
+    Type:         SHT_PROGBITS
+    AddressAlign: 4
+    Content:      "1122334455"
+  - Name:         .data1
+    Type:         SHT_PROGBITS
+    AddressAlign: 4
+    Content:      "1122334455"
+
+# RUN: yaml2obj --docnum=2 %s -o %t2
+# RUN: llvm-objcopy --remove-note=1 %t2 %t2o 2>&1 | FileCheck %s --check-prefix=NOTE_SECTION
+# NOTE_SECTION: 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
+    Content:      "1122334455"

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;