[llvm-readelf/obj] - Stop using `reportError` when dumping notes.

[grimar]

Summary

This starts using reportUniqueWarnings instead of reportError
in the code that is responsible for dumping notes.

[grimar]

• Updated forgotten test.

[jhenderson]

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

121

The mention of the "SHT_NOTE section [index 1]" happens twice redundantly. Same issue with the program header below. Do you think we could omit some of this redudant context?

[grimar]

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

121

The problem is that on one situations notes might report the section index and type:

Elf_Note_Iterator notes_begin(const Elf_Phdr &Phdr, Error &Err) const {
  assert(Phdr.p_type == ELF::PT_NOTE && "Phdr is not of type PT_NOTE");
  ErrorAsOutParameter ErrAsOutParam(&Err);
  if (Phdr.p_offset + Phdr.p_filesz > getBufSize()) {
    Err = createError("PT_NOTE header has invalid offset (0x" +
                      Twine::utohexstr(Phdr.p_offset) + ") or size (0x" +
                      Twine::utohexstr(Phdr.p_filesz) + ")");
    return Elf_Note_Iterator(Err);
  }
  return Elf_Note_Iterator(base() + Phdr.p_offset, Phdr.p_filesz, Err);
}

but in other situations the note iterator might report an error on its own without a context:

class Elf_Note_Iterator_Impl
    : std::iterator<std::forward_iterator_tag, Elf_Note_Impl<ELFT>> {

  // Stop iteration and indicate an overflow.
  void stopWithOverflowError() {
    Nhdr = nullptr;
    *Err = make_error<StringError>("ELF note overflows container",
                                   object_error::parse_failed);
  }

Perhaps, the best solution would be to stop reporting section index/type in Object/ELF.h/notes_begin().
This was introduced by me for llvm-readobj in D64470. Instead we can describe sections/program headers
on the caller side, like we normally do for other warnings/errors.

I'll suggest a patch tomorrow.

[grimar]

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

121

I've prepared the patch: D92081

[grimar]

• Rebased.

[jhenderson]

LGTM, thanks!

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

- Type:     PT_NOTE
     FileSize: 0x20
     FirstSec: .note.gnu.build-id
     LastSec:  .note.gnu.build-id
 
 ## Test tools report an error if a note section has an invalid offset
 ## that goes past the end of file.
 
 # RUN: yaml2obj --docnum=2 -DSHOFFSET=0xffff0000 %s -o %t2.so
-# RUN: not llvm-readelf --notes %t2.so 2>&1 | FileCheck -DFILE=%t2.so %s --check-prefix=ERR1
-# RUN: not llvm-readobj --notes %t2.so 2>&1 | FileCheck -DFILE=%t2.so %s --check-prefix=ERR1
+# RUN: llvm-readelf --notes %t2.so 2>&1 | FileCheck -DFILE=%t2.so %s --check-prefix=ERR1-GNU
+# RUN: llvm-readobj --notes %t2.so 2>&1 | FileCheck -DFILE=%t2.so %s --check-prefix=ERR1-LLVM
 
-# ERR1: error: '[[FILE]]': SHT_NOTE section [index 1] has invalid offset (0xffff0000) or size (0x0)
+# ERR1-GNU:      Displaying notes found in: .note
+# ERR1-GNU-NEXT:   Owner                Data size        Description
+# ERR1-GNU-NEXT: warning: '[[FILE]]': unable to read notes from the SHT_NOTE section with index 1: SHT_NOTE section [index 1] has invalid offset (0xffff0000) or size (0x0)
+# ERR1-GNU-NOT: {{.}}
+
+# ERR1-LLVM:      Notes [
+# ERR1-LLVM-NEXT:   NoteSection {
+# ERR1-LLVM-NEXT:     Name:   .note
+# ERR1-LLVM-NEXT:     Offset: 0xFFFF0000
+# ERR1-LLVM-NEXT:     Size:   0x0
+# ERR1-LLVM-NEXT: warning: '[[FILE]]': unable to read notes from the SHT_NOTE section with index 1: SHT_NOTE section [index 1] has invalid offset (0xffff0000) or size (0x0)
+# ERR1-LLVM-NEXT:   }
+# ERR1-LLVM-NEXT: ]
 
 --- !ELF
 FileHeader:
   Class: ELFCLASS64
   Data:  ELFDATA2LSB
   Type:  ET_EXEC
 Sections:
   - Name:     .note
     Type:     SHT_NOTE
     Notes:    []
     ShOffset: [[SHOFFSET=<none>]]
     ShSize:   [[SHSIZE=<none>]]
 
 ## Test tools report an error if a note section has invalid size
 ## that goes past the end of file.
 
 # RUN: yaml2obj --docnum=2 -DSHSIZE=0xffff0000 %s -o %t3.so
-# RUN: not llvm-readelf --notes %t3.so 2>&1 | FileCheck -DFILE=%t3.so %s --check-prefix=ERR2
-# RUN: not llvm-readobj --notes %t3.so 2>&1 | FileCheck -DFILE=%t3.so %s --check-prefix=ERR2
+# RUN: llvm-readelf --notes %t3.so 2>&1 | FileCheck -DFILE=%t3.so %s --check-prefix=ERR2-GNU
+# RUN: llvm-readobj --notes %t3.so 2>&1 | FileCheck -DFILE=%t3.so %s --check-prefix=ERR2-LLVM
 
-# ERR2: error: '[[FILE]]': SHT_NOTE section [index 1] has invalid offset (0x40) or size (0xffff0000)
+# ERR2-GNU:      Displaying notes found in: .note
+# ERR2-GNU-NEXT:   Owner                Data size        Description
+# ERR2-GNU-NEXT: warning: '[[FILE]]': unable to read notes from the SHT_NOTE section with index 1: SHT_NOTE section [index 1] has invalid offset (0x40) or size (0xffff0000)
+# ERR2-GNU-NOT: {{.}}
+
+# ERR2-LLVM:      Notes [
+# ERR2-LLVM-NEXT:   NoteSection {
+# ERR2-LLVM-NEXT:     Name: .note
+# ERR2-LLVM-NEXT:     Offset: 0x40
+# ERR2-LLVM-NEXT:     Size: 0xFFFF0000
+# ERR2-LLVM-NEXT: warning: '[[FILE]]': unable to read notes from the SHT_NOTE section with index 1: SHT_NOTE section [index 1] has invalid offset (0x40) or size (0xffff0000)
+# ERR2-LLVM-NEXT:   }
+# ERR2-LLVM-NEXT: ]
 
 ## Test tools report an error if a note program header has an invalid offset that
 ## goes past the end of file.
 
 # RUN: yaml2obj --docnum=3 -DPHOFFSET=0xffff0000 %s -o %t4.so
-# RUN: not llvm-readelf --notes %t4.so 2>&1 | FileCheck -DFILE=%t4.so %s --check-prefix=ERR3
-# RUN: not llvm-readobj --notes %t4.so 2>&1 | FileCheck -DFILE=%t4.so %s --check-prefix=ERR3
+# RUN: llvm-readelf --notes %t4.so 2>&1 | FileCheck -DFILE=%t4.so %s --check-prefix=ERR3-GNU
+# RUN: llvm-readobj --notes %t4.so 2>&1 | FileCheck -DFILE=%t4.so %s --check-prefix=ERR3-LLVM
 
-# ERR3: error: '[[FILE]]': PT_NOTE header has invalid offset (0xffff0000) or size (0x0)
+# ERR3-GNU:      Displaying notes found at file offset 0xffff0000 with length 0x00000000:
+# ERR3-GNU-NEXT:   Owner                Data size        Description
+# ERR3-GNU-NEXT: warning: '[[FILE]]': unable to read notes from the PT_NOTE segment with index 1: PT_NOTE header has invalid offset (0xffff0000) or size (0x0)
+# ERR3-GNU-NOT: {{.}}
+
+# ERR3-LLVM:      Notes [
+# ERR3-LLVM-NEXT:   NoteSection {
+# ERR3-LLVM-NEXT:     Name: <?>
+# ERR3-LLVM-NEXT:     Offset: 0xFFFF0000
+# ERR3-LLVM-NEXT:     Size: 0x0
+# ERR3-LLVM-NEXT: warning: '[[FILE]]': unable to read notes from the PT_NOTE segment with index 1: PT_NOTE header has invalid offset (0xffff0000) or size (0x0)
+# ERR3-LLVM-NEXT:   }
+# ERR3-LLVM-NEXT: ]
 
 --- !ELF
 FileHeader:
   Class: ELFCLASS64
   Data:  ELFDATA2LSB
   Type:  ET_CORE
 ProgramHeaders:
   - Type:     PT_NOTE
     Offset:   [[PHOFFSET=<none>]]
     FileSize: [[PHFILESIZE=<none>]]
 
 ## Test tools report an error if a note program header has an invalid size that
 ## goes past the end of file.
 
 # RUN: yaml2obj --docnum=3 -DPHFILESIZE=0xffff0000 %s -o %t5.so
-# RUN: not llvm-readelf --notes %t5.so 2>&1 | FileCheck -DFILE=%t5.so  %s --check-prefix=ERR4
-# RUN: not llvm-readobj --notes %t5.so 2>&1 | FileCheck -DFILE=%t5.so %s --check-prefix=ERR4
+# RUN: llvm-readelf --notes %t5.so 2>&1 | FileCheck -DFILE=%t5.so %s --check-prefix=ERR4-GNU
+# RUN: llvm-readobj --notes %t5.so 2>&1 | FileCheck -DFILE=%t5.so %s --check-prefix=ERR4-LLVM
 
-# ERR4: error: '[[FILE]]': PT_NOTE header has invalid offset (0x0) or size (0xffff0000)
+# ERR4-GNU:      Displaying notes found at file offset 0x00000000 with length 0xffff0000:
+# ERR4-GNU-NEXT:   Owner                Data size        Description
+# ERR4-GNU-NEXT: warning: '[[FILE]]': unable to read notes from the PT_NOTE segment with index 1: PT_NOTE header has invalid offset (0x0) or size (0xffff0000)
+# ERR4-GNU-NOT: {{.}}
+
+# ERR4-LLVM:      Notes [
+# ERR4-LLVM-NEXT:   NoteSection {
+# ERR4-LLVM-NEXT:     Name: <?>
+# ERR4-LLVM-NEXT:     Offset: 0x0
+# ERR4-LLVM-NEXT:     Size: 0xFFFF0000
+# ERR4-LLVM-NEXT: warning: '[[FILE]]': unable to read notes from the PT_NOTE segment with index 1: PT_NOTE header has invalid offset (0x0) or size (0xffff0000)
+# ERR4-LLVM-NEXT:   }
+# ERR4-LLVM-NEXT: ]
 
 ## Check we report a warning when we are unable to locate the PT_NOTE
 ## segment because of broken program headers.
 # RUN: yaml2obj --docnum=1 -DPHENTSIZE=1 -DSHNUM=0 %s -o %t6.so
 # RUN: llvm-readelf --notes %t6.so 2>&1 | FileCheck %s -DFILE=%t6.so --check-prefix=PHENTSIZE-WARN-GNU
 # RUN: llvm-readobj --notes %t6.so 2>&1 | FileCheck %s -DFILE=%t6.so --check-prefix=PHENTSIZE-WARN-LLVM
 
 # PHENTSIZE-WARN-GNU: warning: '[[FILE]]': unable to read program headers to locate the PT_DYNAMIC segment: invalid e_phentsize: 1
 # PHENTSIZE-WARN-GNU: warning: '[[FILE]]': unable to read program headers to locate the PT_NOTE segment: invalid e_phentsize: 1
 
 # PHENTSIZE-WARN-LLVM:      Notes [
 # PHENTSIZE-WARN-LLVM-NEXT: warning: '[[FILE]]': unable to read program headers to locate the PT_NOTE segment: invalid e_phentsize: 1
 # PHENTSIZE-WARN-LLVM-NEXT: ]

llvm/tools/llvm-readobj/ELFDumper.cpp

for (const typename ELFT::Shdr &S : Sections) {
       if (S.sh_type != SHT_NOTE)
         continue;
       StartNotesFn(expectedToOptional(Obj.getSectionName(S)), S.sh_offset,
                    S.sh_size);
       Error Err = Error::success();
       for (const typename ELFT::Note &Note : Obj.notes(S, Err))
         ProcessNoteFn(Note);
       if (Err)
-        reportError(std::move(Err), Dumper.getElfObject().getFileName());
+        Dumper.reportUniqueWarning(
+            createError("unable to read notes from the " + describe(Obj, S) +
+                        ": " + toString(std::move(Err))));
       FinishNotesFn();
     }
     return;
   }
 
   Expected<ArrayRef<typename ELFT::Phdr>> PhdrsOrErr = Obj.program_headers();
   if (!PhdrsOrErr) {
     Dumper.reportUniqueWarning(createError(
         "unable to read program headers to locate the PT_NOTE segment: " +
         toString(PhdrsOrErr.takeError())));
     return;
   }
 
+  size_t I = 0;
   for (const typename ELFT::Phdr &P : *PhdrsOrErr) {
+    ++I;
     if (P.p_type != PT_NOTE)
       continue;
     StartNotesFn(/*SecName=*/None, P.p_offset, P.p_filesz);
     Error Err = Error::success();
     for (const typename ELFT::Note Note : Obj.notes(P, Err))
       ProcessNoteFn(Note);
     if (Err)
-      reportError(std::move(Err), Dumper.getElfObject().getFileName());
+      Dumper.reportUniqueWarning(createError(
+          "unable to read notes from the PT_NOTE segment with index " +
+          Twine(I) + ": " + toString(std::move(Err))));
     FinishNotesFn();
   }
 }
 
 template <class ELFT> void GNUStyle<ELFT>::printNotes() {
   auto PrintHeader = [&](Optional<StringRef> SecName,
                          const typename ELFT::Off Offset,
                          const typename ELFT::Addr Size) {