[llvm-nm] Generalize symbol types 'N' and 'n'

[MaskRay]

Improve the test

[grimar]

tools/llvm-nm/llvm-nm.cpp

915

Shouldn't the new code fail with LLVM_ENABLE_ABI_BREAKING_CHECKS because of removing this line?

[MaskRay]

tools/llvm-nm/llvm-nm.cpp

915

llvm::object::SectionRef::getName(StringRef) still returns error_code... ( it has 95 references so i didn't fix it to use Error instead)

[MaskRay]

tools/llvm-nm/llvm-nm.cpp

915

Oh sorry, it should be Expected<StringRef>. Anyway, I haven't started the refactoring yet..

[grimar]

LGTM (assuming the output is consistent with GNU nm).

tools/llvm-nm/llvm-nm.cpp

915

Ah, I see.

[jhenderson]

LGTM too. I'll update the doc patch.

test/tools/llvm-nm/nonalloc.test

 # RUN: yaml2obj %s -o %t
 # RUN: llvm-nm --no-sort %t | FileCheck %s
 
-# CHECK: n debug_info_main
+# CHECK: N debug_info_main
+# CHECK: n readonly_local
+# CHECK: ? writable_local
+# CHECK: N readonly_global
+# CHECK: ? writable_global
 
 !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_REL
   Machine: EM_X86_64
 Sections:
   - Name: .debug_info
     Type: SHT_PROGBITS
+  - Name: .readonly
+    Type: SHT_PROGBITS
+  - Name: .writable
+    Type: SHT_PROGBITS
+    Flags: [SHF_WRITE]
 Symbols:
   - Name:    debug_info_main
     Section: .debug_info
+  - Name:    readonly_local
+    Section: .readonly
+  - Name:    writable_local
+    Section: .writable
+
+  - Name:    readonly_global
+    Binding: STB_GLOBAL
+    Section: .readonly
+  - Name:    writable_global
+    Binding: STB_GLOBAL
+    Section: .writable

tools/llvm-nm/llvm-nm.cpp

if (SecI != Obj.section_end()) {
     uint32_t Type = SecI->getType();
     uint64_t Flags = SecI->getFlags();
     if (Flags & ELF::SHF_EXECINSTR)
       return 't';
     if (Type == ELF::SHT_NOBITS)
       return 'b';
     if (Flags & ELF::SHF_ALLOC)
       return Flags & ELF::SHF_WRITE ? 'd' : 'r';
-  }
 
-  if (SymI->getELFType() == ELF::STT_SECTION) {
-    Expected<StringRef> Name = SymI->getName();
-    if (!Name) {
-      consumeError(Name.takeError());
+    StringRef SecName;
+    if (SecI->getName(SecName))
       return '?';
-    }
-    return StringSwitch<char>(*Name)
-        .StartsWith(".debug", 'N')
-        .StartsWith(".note", 'n')
-        .StartsWith(".comment", 'n')
-        .Default('?');
+    if (SecName.startswith(".debug"))
+      return 'N';
+    if (!(Flags & ELF::SHF_WRITE))
+      return 'n';
   }
 
-  return 'n';
+  return '?';
 }
 
 static char getSymbolNMTypeChar(COFFObjectFile &Obj, symbol_iterator I) {
   COFFSymbolRef Symb = Obj.getCOFFSymbol(*I);
   // OK, this is COFF.
   symbol_iterator SymI(I);
 
   Expected<StringRef> Name = SymI->getName();