[llvm-readobj] Print symbol version when dumping relocations (PR31564)

[Higuoxing]

Summary

This helps resolve https://bugs.llvm.org/show_bug.cgi?id=31564

[grimar]

tools/llvm-readobj/ELFDumper.cpp

2709–2710

Seems you do not need this->

2710

nit: I suggest to add a comment fot the last arg: SymTab->sh_type == SHT_DYNSYM /* IsDynamic */

[Higuoxing]

Addressed @grimar 's comments.

• Add /* IsDynamic */ hints.
• Sorry, I cannot find another way to get full name of a symbol. Is there another method?

[Higuoxing]

tools/llvm-readobj/ELFDumper.cpp

2709–2710

Sorry, I cannot remove this, I cannot find another way to achieve this.

[jhenderson]

test/tools/llvm-readobj/elf-reloc-symbol-with-versioning.test

78

Please use mangled names, to show that versioned symbols are demangled (e.g. _Z2f1v becomes f1()@v3 etc).

[Higuoxing]

Addressed @jhenderson 's comments.

• Use -demangle option to test that mangled name can be demangled correctly.

[jhenderson]

test/tools/llvm-readobj/elf-reloc-symbol-with-versioning.test

2

Thinking about a past bug to do with symbol versioning, perhaps it's worth one of these symbols not having a version, to show that symbol versioning it only printed for symbols with version details?

[Higuoxing]

test/tools/llvm-readobj/elf-reloc-symbol-with-versioning.test

2

Do you mean that a dynamic symbol that not included in .gnu.version/.gnu.version_d/.gnu.version_r section? Am I right?

[jhenderson]

test/tools/llvm-readobj/elf-reloc-symbol-with-versioning.test

2

Yes, exactly.

[Higuoxing]

Addressed @jhenderson 's comments

• Add a dynamic symbol without versioning.

[jhenderson]

LGTM.

test/tools/llvm-readobj/elf-reloc-symbol-with-versioning.test

3–4

Nit: You don't need the --strict-whitespace switches.

[Higuoxing]

test/tools/llvm-readobj/elf-reloc-symbol-with-versioning.test

3–4

Oh, Because my test cases are copied from terminal. Just to make sure the number of blanks are right. Forget to remove this flag.

[Higuoxing]

In D59175#1426072, @jhenderson wrote:

LGTM.

Thanks for reviewing :)

[Higuoxing]

.

test/tools/llvm-readobj/elf-reloc-symbol-with-versioning.test

+# RUN: yaml2obj %s > %t.o
+# RUN: llvm-readobj -r %t.o | FileCheck %s --check-prefix LLVM
+# RUN: llvm-readelf -r %t.o | FileCheck %s --check-prefix GNU
+
+# GNU:      Relocation section '.rela.plt' at offset {{.*}} contains 3 entries:
+# GNU-NEXT:     Offset             Info             Type               Symbol's Value  Symbol's Name + Addend
+# GNU-NEXT: 0000000000013018  0000000100000007 R_X86_64_JUMP_SLOT     0000000000000000 f1@v3 + 0
+# GNU-NEXT: 0000000000013020  0000000200000007 R_X86_64_JUMP_SLOT     0000000000000000 f2@v2 + 0
+# GNU-NEXT: 0000000000013028  0000000300000007 R_X86_64_JUMP_SLOT     0000000000000000 g1@v1 + 0
+
+# LLVM:      Relocations [
+# LLVM-NEXT:   Section (3) .rela.plt {
+# LLVM-NEXT:     0x13018 R_X86_64_JUMP_SLOT f1@v3 0x0
+# LLVM-NEXT:     0x13020 R_X86_64_JUMP_SLOT f2@v2 0x0
+# LLVM-NEXT:     0x13028 R_X86_64_JUMP_SLOT g1@v1 0x0
+# LLVM-NEXT:   }
+# LLVM-NEXT: ]
+
+--- !ELF
+FileHeader:      
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_EXEC
+  Machine:         EM_X86_64
+  Entry:           0x0000000000000000
+Sections:        
+  - Name:            .gnu.version
+    Type:            SHT_GNU_versym
+    Flags:           [ SHF_ALLOC ]
+    Link:            .dynsym
+    AddressAlign:    0x0000000000000002
+    EntSize:         0x0000000000000002
+    Entries:         [ 0, 2, 3, 4 ]
+  - Name:            .gnu.version_r
+    Type:            SHT_GNU_verneed
+    Flags:           [ SHF_ALLOC ]
+    Link:            .dynstr
+    AddressAlign:    0x0000000000000004
+    Info:            0x0000000000000002
+    Dependencies:    
+      - Version:         1
+        File:            verneed1.so.0
+        Entries:         
+          - Name:            v2
+            Hash:            1938
+            Flags:           0
+            Other:           3
+          - Name:            v3
+            Hash:            1939
+            Flags:           0
+            Other:           2
+      - Version:         1
+        File:            verneed2.so.0
+        Entries:         
+          - Name:            v1
+            Hash:            1937
+            Flags:           0
+            Other:           4
+  - Name:            .rela.plt
+    Type:            SHT_RELA
+    Flags:           [ SHF_ALLOC ]
+    Info:            0
+    Link:            7
+    AddressAlign:    0x0000000000000008
+    EntSize:         0x0000000000000018
+    Relocations:     
+      - Offset:          0x0000000000013018
+        Symbol:          f1
+        Type:            R_X86_64_JUMP_SLOT
+      - Offset:          0x0000000000013020
+        Symbol:          f2
+        Type:            R_X86_64_JUMP_SLOT
+      - Offset:          0x0000000000013028
+        Symbol:          g1
+        Type:            R_X86_64_JUMP_SLOT
+Symbols:
+  Global:
+    - Name:            f1
+    - Name:            f2
+    - Name:            g1
+DynamicSymbols:  
+  Global:          
+    - Name:            f1
+    - Name:            f2
+    - Name:            g1
+...

tools/llvm-readobj/ELFDumper.cpp

void GNUStyle<ELFT>::printRelocation(const ELFO *Obj, const Elf_Shdr *SymTab,
   const Elf_Sym *Sym = unwrapOrError(Obj->getRelocationSymbol(&R, SymTab));
   std::string TargetName;
   if (Sym && Sym->getType() == ELF::STT_SECTION) {
     const Elf_Shdr *Sec = unwrapOrError(
         Obj->getSection(Sym, SymTab, this->dumper()->getShndxTable()));
     TargetName = unwrapOrError(Obj->getSectionName(Sec));
   } else if (Sym) {
     StringRef StrTable = unwrapOrError(Obj->getStringTableForSymtab(*SymTab));
-    TargetName = maybeDemangle(unwrapOrError(Sym->getName(StrTable)));
+    TargetName = this->dumper()->getFullSymbolName(
+        Sym, StrTable, SymTab->sh_type == SHT_DYNSYM /* IsDynamic */);
   }
 
   unsigned Width = ELFT::Is64Bits ? 16 : 8;
   Fields[0].Str = to_string(format_hex_no_prefix(R.r_offset, Width));
   Fields[1].Str = to_string(format_hex_no_prefix(R.r_info, Width));
   Fields[2].Str = RelocName.str();
   if (Sym)
     Fields[3].Str = to_string(format_hex_no_prefix(Sym->getValue(), Width));
void LLVMStyle<ELFT>::printRelocation(const ELFO *Obj, Elf_Rela Rel,
   std::string TargetName;
   const Elf_Sym *Sym = unwrapOrError(Obj->getRelocationSymbol(&Rel, SymTab));
   if (Sym && Sym->getType() == ELF::STT_SECTION) {
     const Elf_Shdr *Sec = unwrapOrError(
         Obj->getSection(Sym, SymTab, this->dumper()->getShndxTable()));
     TargetName = unwrapOrError(Obj->getSectionName(Sec));
   } else if (Sym) {
     StringRef StrTable = unwrapOrError(Obj->getStringTableForSymtab(*SymTab));
-    TargetName = maybeDemangle(unwrapOrError(Sym->getName(StrTable)));
+    TargetName = this->dumper()->getFullSymbolName(
+        Sym, StrTable, SymTab->sh_type == SHT_DYNSYM /* IsDynamic */);
   }
 
   if (opts::ExpandRelocs) {
     DictScope Group(W, "Relocation");
     W.printHex("Offset", Rel.r_offset);
     W.printNumber("Type", RelocName, (int)Rel.getType(Obj->isMips64EL()));
     W.printNumber("Symbol", !TargetName.empty() ? TargetName : "-",
                   Rel.getSymbol(Obj->isMips64EL()));