[llvm-nm] Display STT_GNU_IFUNC as 'i'

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D71803

test/LTO/Resolution/X86/ifunc.ll

@@ -1,7 +1,7 @@
 ; RUN: opt -module-summary -o %t.bc %s
 ; RUN: llvm-lto2 run %t.bc -r %t.bc,foo,pl -o %t2
 ; RUN: llvm-nm %t2.1 | FileCheck %s
-; CHECK: T foo
+; CHECK: i foo
 ; CHECK: t foo_ifunc
 
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"

test/tools/llvm-nm/ifunc.test

@@ -0,0 +1,27 @@
+## Test that the symbol type of STT_GNU_IFUNC is 'i'.
+
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-nm --no-sort %t | FileCheck %s
+
+# CHECK:      i ifunc_local
+# CHECK-NEXT: i 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

tools/llvm-nm/llvm-nm.cpp

@@ -1133,15 +1133,18 @@ static char getNMSectionTagAndName(SymbolicFile &Obj, basic_symbol_iterator I,
     Ret = getSymbolNMTypeChar(*MachO, I);
   else if (WasmObjectFile *Wasm = dyn_cast<WasmObjectFile>(&Obj))
     Ret = getSymbolNMTypeChar(*Wasm, I);
-  else
-    Ret = getSymbolNMTypeChar(cast<ELFObjectFileBase>(Obj), I);
+  else if (ELFObjectFileBase *ELF = dyn_cast<ELFObjectFileBase>(&Obj)) {
+    if (ELFSymbolRef(*I).getELFType() == ELF::STT_GNU_IFUNC)
+      return 'i';
+    Ret = getSymbolNMTypeChar(*ELF, I);
+    if (ELFSymbolRef(*I).getBinding() == ELF::STB_GNU_UNIQUE)
+      return Ret;
+  } else
+    llvm_unreachable("unknown binary format");
 
   if (!(Symflags & object::SymbolRef::SF_Global))
     return Ret;
 
-  if (Obj.isELF() && ELFSymbolRef(*I).getBinding() == ELF::STB_GNU_UNIQUE)
-    return Ret;
-
   return toupper(Ret);
 }