[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 ↗

(On Diff #248894)

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/symbol-table-ifunc.test

+## Test that we print 'i' for STT_GNU_IFUNC.
+
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-objdump -t %t | FileCheck %s
+
+# CHECK:      SYMBOL TABLE:
+# CHECK-NEXT: 0000000000000000 l   i   .text  0000000000000000 ifunc_local
+# CHECK-NEXT: 0000000000000000 g   i   .text  0000000000000000 ifunc_global
+
+!ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_X86_64
+Sections:
+  - Name:  .text
+    Type:  SHT_PROGBITS
+    Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+Symbols:
+  - Name:    ifunc_local
+    Type:    STT_GNU_IFUNC
+    Binding: STB_LOCAL
+    Section: .text
+  - Name:    ifunc_global
+    Type:    STT_GNU_IFUNC
+    Binding: STB_GLOBAL
+    Section: .text

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()) {