[llvm-objdump] --syms: print 'i' for STT_GNU_IFUNC

[MaskRay]

llvm::object::BasicSymbolRef::SF_Indirect exists but I don't think it is suitable.

In theory, I may be possible, but I cannot find any binutils test for I.

[MaskRay]

Rebase on D75796

[MaskRay]

Add a local STT_GNU_IFUNC

[MaskRay]

Move

[Higuoxing]

LGTM

[grimar]

I confirm this matches GNU objdump for me.

llvm/test/tools/llvm-objdump/ELF/symbol-table.test

44

Perhaps it is not clear why there is an empty line between locals and globals.
I'd either remove it or add a comment.

llvm/tools/llvm-objdump/llvm-objdump.cpp

1911

nit: you do not need curly bracers.

[MaskRay]

llvm/tools/llvm-objdump/llvm-objdump.cpp

1911

It is to minimize diff for D75797 :)

[jhenderson]

LGTM.

In D75793#1910789, @MaskRay wrote:

llvm::object::BasicSymbolRef::SF_Indirect exists but I don't think it is suitable.

In theory, I may be possible, but I cannot find any binutils test for I.

What would a I value represent?

[MaskRay]

In D75793#1912081, @jhenderson wrote:

LGTM.

In D75793#1910789, @MaskRay wrote:

llvm::object::BasicSymbolRef::SF_Indirect exists but I don't think it is suitable.

In theory, I may be possible, but I cannot find any binutils test for I.

What would a I value represent?

binutils-gdb/bfd/syms.c:bfd_print_symbol_vandr. The I character represents BFD_INDIRECT. By inspecting its references, it is only used by some intermediate representations (bfdlink.c). It cannot be produced when BFD parses an object file, so the rule in bfd_print_symbol_vandr may be dead.

[MaskRay]

Rebase. Rename Indirect to Ifunc because the code path is only possible for STT_GNU_IFUNC.

[jhenderson]

LGTM, with one suggestion.

llvm/tools/llvm-objdump/llvm-objdump.cpp

1907

Maybe IFunc rather than Ifunc, since it's short for "Indirect Function"?

[MaskRay]

Rebase

llvm/test/tools/llvm-objdump/ELF/symbol-table.test

 # RUN: yaml2obj --docnum=1 %s -o %t
 # RUN: llvm-objdump --syms %t > %t.txt
 # RUN: llvm-objdump -t %t | cmp - %t.txt
 # RUN: FileCheck %s --input-file=%t.txt --match-full-lines --strict-whitespace
 
 #      CHECK:SYMBOL TABLE:
 # CHECK-NEXT:0000000000001fff l     F .text 0000000000000000 local_func
 # CHECK-NEXT:0000000000002000 l     O .data 0000000000000000 local_object
 # CHECK-NEXT:0000000000000000 l       *ABS* 0000000000000000 local_abs
+# CHECK-NEXT:0000000000000000 l   i   .text 0000000000000000 local_ifunc
 # CHECK-NEXT:0000000000000000 g     F .text 000000000000000f func
 # CHECK-NEXT:0000000000000000 g     O .data 0000000000000010 object
 # CHECK-NEXT:0000000000000000         *UND* 0000000000000000 undef
 # CHECK-NEXT:0000000000000000 g       *ABS* 0000000000000000 abs
 # CHECK-NEXT:0000000000000000         *COM* 0000000000000000 common
-# CHECK-NEXT:0000000000000000 g       .text 0000000000000000 ifunc
+# CHECK-NEXT:0000000000000000 g   i   .text 0000000000000000 ifunc
 # CHECK-NEXT:0000000000000000 g     O .data 0000000000000000 gnu_unique
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_EXEC
   Machine: EM_X86_64
 Sections:
   - Name:  .text
     Type:  SHT_PROGBITS
   - Name:  .data
     Type:  SHT_PROGBITS
 Symbols:
   - Name:    local_func
     Type:    STT_FUNC
     Section: .text
     Value:   0x1fff
   - Name:    local_object
     Type:    STT_OBJECT
     Section: .data
     Value:   0x2000
   - Name:    local_abs
     Index:   SHN_ABS
+  - Name:    local_ifunc
+    Type:    STT_GNU_IFUNC
+    Section: .text
 
   - Name:    func
     Type:    STT_FUNC
     Size:    0xf
     Binding: STB_GLOBAL
     Section: .text
   - Name:    object
     Type:    STT_OBJECT
     Size:    0x10

llvm/tools/llvm-objdump/llvm-objdump.cpp

if (Type == SymbolRef::ST_Debug && Section != O->section_end()) {
                            ArchitectureName);
     }
 
     bool Global = Flags & SymbolRef::SF_Global;
     bool Weak = Flags & SymbolRef::SF_Weak;
     bool Absolute = Flags & SymbolRef::SF_Absolute;
     bool Common = Flags & SymbolRef::SF_Common;
     bool Hidden = Flags & SymbolRef::SF_Hidden;
+    char Indirect = ' ';
+    if (auto *ELF = dyn_cast<ELFObjectFileBase>(O))
+      if (ELFSymbolRef(*I).getELFType() == ELF::STT_GNU_IFUNC)
+        Indirect = 'i';
 
     char GlobLoc = ' ';
     if ((Section != O->section_end() || Absolute) && !Weak)
       GlobLoc = Global ? 'g' : 'l';
     char Debug = (Type == SymbolRef::ST_Debug || Type == SymbolRef::ST_File)
                  ? 'd' : ' ';
     char FileFunc = ' ';
     if (Type == SymbolRef::ST_File)
       FileFunc = 'f';
     else if (Type == SymbolRef::ST_Function)
       FileFunc = 'F';
     else if (Type == SymbolRef::ST_Data)
       FileFunc = 'O';
 
     const char *Fmt = O->getBytesInAddress() > 4 ? "%016" PRIx64 :
                                                    "%08" PRIx64;
 
     outs() << format(Fmt, Address) << " "
            << GlobLoc // Local -> 'l', Global -> 'g', Neither -> ' '
            << (Weak ? 'w' : ' ') // Weak?
            << ' ' // Constructor. Not supported yet.
            << ' ' // Warning. Not supported yet.
-           << ' ' // Indirect reference to another symbol.
+           << Indirect // Indirect reference to another symbol.
            << Debug // Debugging (d) or dynamic (D) symbol.
            << FileFunc // Name of function (F), file (f) or object (O).
            << ' ';
     if (Absolute) {
       outs() << "*ABS*";
     } else if (Common) {
       outs() << "*COM*";
     } else if (Section == O->section_end()) {