[llvm-readobj] - Fix letters used for dumping section types in GNU style.

[grimar]

Summary

I've noticed that when we have all regular flags set, we print "WAEXMSILoGTx"
instead of "WAXMSILOGTCE" printed by GNU readelf.

It happens because:

1. We print SHF_EXCLUDE at the wrong place.
2. We do not recognize SHF_COMPRESSED, we print "x" instead of "C".
3. We print "o" instead of "O" for SHF_OS_NONCONFORMING.

This patch fixes differences and adds test cases.

[jhenderson]

llvm/test/tools/llvm-readobj/ELF/section-flags.test

74

Nit: (0x100)

llvm/tools/llvm-readobj/ELFDumper.cpp

1447–1449

Should we test these two too? It looks like there's no testing here, but GNU supposedly prints them (I have not verified that this is the case).

[grimar]

llvm/tools/llvm-readobj/ELFDumper.cpp

1447–1449

It is similar to
https://reviews.llvm.org/D71333#inline-644830
(i.e. this follow-up for D71333 is in my TODO list and waits for D71411 that have be landed first)

(I actually working on follow-ups we discussed, and made this patch because plan to
remove these 2 from this array (because they are masks).)

[grimar]

• Addressed review comments.

[grimar]

llvm/tools/llvm-readobj/ELFDumper.cpp

1447–1449

but GNU supposedly prints them (I have not verified that this is the case)

Yes, it does print o and p. For example, we have a sample in D71333:

--- !ELF
FileHeader:
  Class:   ELFCLASS32
  Data:    ELFDATA2LSB
  Type:    ET_REL
  Machine: EM_MIPS
Sections:
  - Name:  .mips
    Type:  SHT_PROGBITS
    Flags: [ SHF_MIPS_NODUPES, SHF_MIPS_NAMES, SHF_MIPS_LOCAL, SHF_MIPS_NOSTRIP,
              SHF_MIPS_GPREL, SHF_MIPS_MERGE, SHF_MIPS_ADDR, SHF_MIPS_STRING ]

GNU prints:

[Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
  [ 0]                   NULL            00000000 000000 000000 00      0   0  0
  [ 1] .mips             PROGBITS        00000000 000034 000000 00 Dop  0   0  0

[jhenderson]

LGTM. Thanks!

llvm/test/MC/ELF/exclude-debug-dwo.s

 # RUN: llvm-mc -triple x86_64-pc-linux-gnu %s -filetype=obj -o %t.o
 # RUN: llvm-readelf -S %t.o | FileCheck %s
 
 ## Check we add SHF_EXCLUDE flag for .dwo debug sections.
 # CHECK: .debug_info.dwo        {{.*}} E
 # CHECK: .debug_types.dwo       {{.*}} E
 # CHECK: .debug_abbrev.dwo      {{.*}} E
-# CHECK: .debug_str.dwo         {{.*}} EMS
+# CHECK: .debug_str.dwo         {{.*}} MSE
 # CHECK: .debug_line.dwo        {{.*}} E
 # CHECK: .debug_loc.dwo         {{.*}} E
 # CHECK: .debug_str_offsets.dwo {{.*}} E
 
 .section .debug_info.dwo
 nop
 
 .section .debug_types.dwo

llvm/test/tools/llvm-readobj/ELF/section-flags.test

 # LLVM-NEXT:   SHF_WRITE (0x1)
 # LLVM-NEXT: ]
 
 # LLVM:      Name: noflags
 # LLVM-NEXT: Type: SHT_PROGBITS
 # LLVM-NEXT: Flags [ (0x0)
 # LLVM-NEXT: ]
 
-# GNU: [Nr] Name     Type     Address          Off    Size   ES Flg          Lk Inf Al
-# GNU: [ 1] allflags PROGBITS 0000000000000000 000040 000000 00 WAEXMSILoGTx 0   0  0
-# GNU: [ 2] noflags  PROGBITS 0000000000000000 000040 000000 00              0   0  0
+# LLVM:      Name: write
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x1)
+# LLVM-NEXT:   SHF_WRITE (0x1)
+# LLVM-NEXT: ]
+
+# LLVM:      Name: alloc
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x2)
+# LLVM-NEXT:   SHF_ALLOC (0x2)
+# LLVM-NEXT: ]
+
+# LLVM:      Name: exec
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x4)
+# LLVM-NEXT:   SHF_EXECINSTR (0x4)
+# LLVM-NEXT: ]
+
+# LLVM:      Name: merge
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x10)
+# LLVM-NEXT:   SHF_MERGE (0x10)
+# LLVM-NEXT: ]
+
+# LLVM:      Name: strings
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x20)
+# LLVM-NEXT:   SHF_STRINGS (0x20)
+# LLVM-NEXT: ]
+
+# LLVM:      Name: infolink
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x40)
+# LLVM-NEXT:   SHF_INFO_LINK (0x40)
+# LLVM-NEXT: ]
+
+# LLVM:      Name: linkorder
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x80)
+# LLVM-NEXT:   SHF_LINK_ORDER (0x80)
+# LLVM-NEXT: ]
+
+# LLVM:      Name: nonconforming
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x100)
+# LLVM-NEXT:   SHF_OS_NONCONFORMING (0x100)
+# LLVM-NEXT: ]
+
+# LLVM:      Name: group
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x200)
+# LLVM-NEXT:   SHF_GROUP (0x200)
+# LLVM-NEXT: ]
+
+# LLVM:      Name: tls
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x400)
+# LLVM-NEXT:   SHF_TLS (0x400)
+# LLVM-NEXT: ]
+
+# LLVM:      Name: compressed
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x800)
+# LLVM-NEXT:   SHF_COMPRESSED (0x800)
+# LLVM-NEXT: ]
+
+# LLVM:      Name: exclude
+# LLVM-NEXT: Type: SHT_PROGBITS
+# LLVM-NEXT: Flags [ (0x80000000)
+# LLVM-NEXT:   SHF_EXCLUDE (0x80000000)
+# LLVM-NEXT: ]
+
+# GNU: [Nr] Name          Type     Address          Off    Size   ES Flg          Lk Inf Al
+# GNU: [ 1] allflags      PROGBITS 0000000000000000 000040 000000 00 WAXMSILOGTCE 0   0  0
+# GNU: [ 2] noflags       PROGBITS 0000000000000000 000040 000000 00              0   0  0
+# GNU: [ 3] write         PROGBITS 0000000000000000 000040 000000 00 W            0   0  0
+# GNU: [ 4] alloc         PROGBITS 0000000000000000 000040 000000 00 A            0   0  0
+# GNU: [ 5] exec          PROGBITS 0000000000000000 000040 000000 00 X            0   0  0
+# GNU: [ 6] merge         PROGBITS 0000000000000000 000040 000000 00 M            0   0  0
+# GNU: [ 7] strings       PROGBITS 0000000000000000 000040 000000 00 S            0   0  0
+# GNU: [ 8] infolink      PROGBITS 0000000000000000 000040 000000 00 I            0   0  0
+# GNU: [ 9] linkorder     PROGBITS 0000000000000000 000040 000000 00 L            0   0  0
+# GNU: [10] nonconforming PROGBITS 0000000000000000 000040 000000 00 O            0   0  0
+# GNU: [11] group         PROGBITS 0000000000000000 000040 000000 00 G            0   0  0
+# GNU: [12] tls           PROGBITS 0000000000000000 000040 000000 00 T            0   0  0
+# GNU: [13] compressed    PROGBITS 0000000000000000 000040 000000 00 C            0   0  0
+# GNU: [14] exclude       PROGBITS 0000000000000000 000040 000000 00 E            0   0  0
 
 --- !ELF
 FileHeader:
   Class:    ELFCLASS64
   Data:     ELFDATA2LSB
   Type:     ET_REL
   Machine:  EM_X86_64
   Flags:    []
 Sections:
   - Name:  allflags
     Type:  SHT_PROGBITS
     Flags: [ SHF_WRITE, SHF_ALLOC, SHF_EXECINSTR, SHF_MERGE,
             SHF_STRINGS, SHF_INFO_LINK, SHF_LINK_ORDER, SHF_OS_NONCONFORMING,
             SHF_GROUP, SHF_TLS, SHF_COMPRESSED, SHF_EXCLUDE ]
   - Name:  noflags
     Type:  SHT_PROGBITS
     Flags: [ ]
+  - Name:  write
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_WRITE ]
+  - Name:  alloc
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_ALLOC ]
+  - Name:  exec
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_EXECINSTR ]
+  - Name:  merge
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_MERGE ]
+  - Name:  strings
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_STRINGS ]
+  - Name:  infolink
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_INFO_LINK ]
+  - Name:  linkorder
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_LINK_ORDER ]
+  - Name:  nonconforming
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_OS_NONCONFORMING ]
+  - Name:  group
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_GROUP ]
+  - Name:  tls
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_TLS ]
+  - Name:  compressed
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_COMPRESSED ]
+  - Name:  exclude
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_EXCLUDE ]

llvm/tools/llvm-readobj/ELFDumper.cpp

if (Flag & ELF::GRP_COMDAT)
     return "COMDAT";
   else
     return "(unknown)";
 }
 
 static const EnumEntry<unsigned> ElfSectionFlags[] = {
   ENUM_ENT(SHF_WRITE,            "W"),
   ENUM_ENT(SHF_ALLOC,            "A"),
-  ENUM_ENT(SHF_EXCLUDE,          "E"),
   ENUM_ENT(SHF_EXECINSTR,        "X"),
   ENUM_ENT(SHF_MERGE,            "M"),
   ENUM_ENT(SHF_STRINGS,          "S"),
   ENUM_ENT(SHF_INFO_LINK,        "I"),
   ENUM_ENT(SHF_LINK_ORDER,       "L"),
-  ENUM_ENT(SHF_OS_NONCONFORMING, "o"),
+  ENUM_ENT(SHF_OS_NONCONFORMING, "O"),
   ENUM_ENT(SHF_GROUP,            "G"),
   ENUM_ENT(SHF_TLS,              "T"),
+  ENUM_ENT(SHF_COMPRESSED,       "C"),
+  ENUM_ENT(SHF_EXCLUDE,          "E"),
   ENUM_ENT(SHF_MASKOS,           "o"),
   ENUM_ENT(SHF_MASKPROC,         "p"),
-  ENUM_ENT_1(SHF_COMPRESSED),
 };
 
 static const EnumEntry<unsigned> ElfXCoreSectionFlags[] = {
   LLVM_READOBJ_ENUM_ENT(ELF, XCORE_SHF_CP_SECTION),
   LLVM_READOBJ_ENUM_ENT(ELF, XCORE_SHF_DP_SECTION)
 };
 
 static const EnumEntry<unsigned> ElfARMSectionFlags[] = {
   LLVM_READOBJ_ENUM_ENT(ELF, SHF_ARM_PURECODE)
for (auto Entry : ElfSectionFlags) {
     case ELF::SHF_EXECINSTR:
     case ELF::SHF_MERGE:
     case ELF::SHF_STRINGS:
     case ELF::SHF_INFO_LINK:
     case ELF::SHF_LINK_ORDER:
     case ELF::SHF_OS_NONCONFORMING:
     case ELF::SHF_GROUP:
     case ELF::SHF_TLS:
+    case ELF::SHF_COMPRESSED:
     case ELF::SHF_EXCLUDE:
       Str += Entry.AltName;
       break;
     default:
       if (Flag & ELF::SHF_MASKOS)
         Str += "o";
       else if (Flag & ELF::SHF_MASKPROC)
         Str += "p";