[llvm-readobj] - Teach readobj to print DT_FILTER dynamic tag in human readable form.

[grimar]

Summary

Nothing special here,
output format is similar to the format used by binutils readelf and ELF Tool Chain readelf.

[emaste]

Should we instead switch DT_NEEDED to be like DT_AUXILIARY? This would be similar to the format used by binutils readelf and ELF Tool Chain readelf.

ELF Tool Chain:

Dynamic section at offset 0xd30 contains 25 entries:
  Tag                Type                  Name/Value
 0x0000000000000001 NEEDED               Shared library: [libc.so.7]
 0x000000000000000e SONAME               Library soname: [libdl.so.1]

Binutils:

Dynamic section at offset 0xd30 contains 25 entries:
  Tag        Type                         Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.7]
 0x000000000000000e (SONAME)             Library soname: [libdl.so.1]

[grimar]

In D35351#807913, @emaste wrote:

Should we instead switch DT_NEEDED to be like DT_AUXILIARY? This would be similar to the format used by binutils readelf and ELF Tool Chain readelf.

Ah, now I see why I did it in that way for DT_AUXILIARY in D24138. I was wondering today why I implemented such a inconsistent output format that time :)
So do what other think ? Should we be consistent with other readelf utils it seems ?

[grimar]

• Make output format to be consistent with binutils/ELF Tool Chain readelf tools.

[grimar]

• Updated 2 more testcases affected.

[emaste]

One note, the ordering of the value tags differs wrt GNU ld. It shouldn't matter, just something I noticed.

GNU ld.bfd 2.17.50

  Tag        Type                         Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.7]
 0x000000000000000e (SONAME)             Library soname: [libdl.so.1]
 0x000000007fffffff (FILTER)             Filter library: [libc.so.7]
 0x000000000000000c (INIT)               0x738
 0x000000000000000d (FINI)               0xa48
 0x0000000000000004 (HASH)               0x158
...

Patched lld

  Tag        Type                         Name/Value
 0x000000007fffffff (FILTER)             Filter library: [libc.so.7]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.7]
 0x000000000000000e (SONAME)             Library soname: [libdl.so.1]
 0x0000000000000007 (RELA)               0x6c0
 0x0000000000000008 (RELASZ)             96 (bytes)
...

test/Object/no-section-table.test

 RUN: llvm-readobj %p/Inputs/no-section-table.so -hash-table -dynamic-table \
 RUN:   | FileCheck %s
 
 CHECK: DynamicSection [ (24 entries)
 CHECK:   Tag                Type                 Name/Value
-CHECK:   0x0000000000000001 NEEDED               SharedLibrary (libc.so.6)
+CHECK:   0x0000000000000001 NEEDED               Shared library: [libc.so.6]
 CHECK:   0x000000000000000C INIT                 0x4B8
 CHECK:   0x000000000000000D FINI                 0x618
 CHECK:   0x0000000000000019 INIT_ARRAY           0x2006C0
 CHECK:   0x000000000000001B INIT_ARRAYSZ         8 (bytes)
 CHECK:   0x000000000000001A FINI_ARRAY           0x2006C8
 CHECK:   0x000000000000001C FINI_ARRAYSZ         8 (bytes)
 CHECK:   0x0000000000000004 HASH                 0x158
 CHECK:   0x0000000000000005 STRTAB               0x2D8

test/Object/readobj-shared-object.test

 ELF:     Binding: Global
 ELF:     Type: None
 ELF:     Section: Absolute (0xFFF1)
 ELF:   }
 ELF: ]
 
 ELF32: DynamicSection [ (9 entries)
 ELF32:   Tag        Type                 Name/Value
-ELF32:   0x00000001 NEEDED               SharedLibrary (libc.so.6)
-ELF32:   0x00000001 NEEDED               SharedLibrary (libm.so.6)
-ELF32:   0x0000000E SONAME               LibrarySoname (libfoo.so)
+ELF32:   0x00000001 NEEDED               Shared library: [libc.so.6]
+ELF32:   0x00000001 NEEDED               Shared library: [libm.so.6]
+ELF32:   0x0000000E SONAME               Library soname: [libfoo.so]
 ELF32:   0x00000004 HASH                 {{[0-9a-f]+}}
 ELF32:   0x00000005 STRTAB               {{[0-9a-f]+}}
 ELF32:   0x00000006 SYMTAB               {{[0-9a-f]+}}
 ELF32:   0x0000000A STRSZ                {{[0-9]+}} (bytes)
 ELF32:   0x0000000B SYMENT               {{[0-9]+}} (bytes)
 ELF32:   0x00000000 NULL                 0x0
 ELF32: ]
 
 ELF64: DynamicSection [ (9 entries)
 ELF64:   Tag        Type                 Name/Value
-ELF64:   0x0000000000000001 NEEDED               SharedLibrary (libc.so.6)
-ELF64:   0x0000000000000001 NEEDED               SharedLibrary (libm.so.6)
-ELF64:   0x000000000000000E SONAME               LibrarySoname (libfoo.so)
+ELF64:   0x0000000000000001 NEEDED               Shared library: [libc.so.6]
+ELF64:   0x0000000000000001 NEEDED               Shared library: [libm.so.6]
+ELF64:   0x000000000000000E SONAME               Library soname: [libfoo.so]
 ELF64:   0x0000000000000004 HASH                 {{[0-9a-f]+}}
 ELF64:   0x0000000000000005 STRTAB               {{[0-9a-f]+}}
 ELF64:   0x0000000000000006 SYMTAB               {{[0-9a-f]+}}
 ELF64:   0x000000000000000A STRSZ                {{[0-9]+}} (bytes)
 ELF64:   0x000000000000000B SYMENT               {{[0-9]+}} (bytes)
 ELF64:   0x0000000000000000 NULL                 0x0
 ELF64: ]
 
 
 ELF:      NeededLibraries [
 ELF-NEXT:  libc.so.6
 ELF-NEXT:  libm.so.6
 ELF-NEXT: ]

test/tools/llvm-readobj/Inputs/dynamic-table.c

 // clang -target x86_64-linux-gnu -shared -fPIC -lc dynamic-table.c \
-//       -o dynamic-table-so.x86 -Wl,-f,aux_val
+//       -o dynamic-table-so.x86 -Wl,-f,aux.so -Wl,-F,filter.so
 // clang -target mipsel-linux-gnu -shared -fPIC -lc dynamic-table.c \
 //       -o dynamic-table-so.mips
 // clang -target mipsel-linux-gnu -lc dynamic-table.c \
 //       -o dynamic-table-exe.mips
-// clang -target aarch64-linux-gnu -fPIC -shared dynamic-table.c \ 
+// clang -target aarch64-linux-gnu -fPIC -shared dynamic-table.c\
 //       -o dynamic-table-so.aarch64
 int puts(const char *);
 
 __thread int foo;
 
 int main(void) {
   puts("Hello, World");
   foo = 0;
 }

test/tools/llvm-readobj/dynamic.test

 // Check dynamic section tags in case of shared library file.
 RUN: llvm-readobj -dynamic-table %p/Inputs/dynamic-table-so.mips \
 RUN:     | FileCheck %s -check-prefix ELF-MIPS
 
 ELF-MIPS: Format: ELF32-mips
 ELF-MIPS: Arch: mipsel
 ELF-MIPS: AddressSize: 32bit
 ELF-MIPS: LoadName:
 ELF-MIPS: DynamicSection [ (23 entries)
 ELF-MIPS:   Tag        Type                 Name/Value
-ELF-MIPS:   0x00000001 NEEDED               SharedLibrary (libc.so.6)
+ELF-MIPS:   0x00000001 NEEDED               Shared library: [libc.so.6]
 ELF-MIPS:   0x0000000C INIT                 0x528
 ELF-MIPS:   0x0000000D FINI                 0x860
 ELF-MIPS:   0x00000004 HASH                 0x210
 ELF-MIPS:   0x00000005 STRTAB               0x3D8
 ELF-MIPS:   0x00000006 SYMTAB               0x2A8
 ELF-MIPS:   0x0000000A STRSZ                231 (bytes)
 ELF-MIPS:   0x0000000B SYMENT               16 (bytes)
 ELF-MIPS:   0x00000003 PLTGOT               0x108E0

 RUN:     | FileCheck %s -check-prefix ELF-MIPS-EXE
 
 ELF-MIPS-EXE: Format: ELF32-mips
 ELF-MIPS-EXE: Arch: mipsel
 ELF-MIPS-EXE: AddressSize: 32bit
 ELF-MIPS-EXE: LoadName:
 ELF-MIPS-EXE: DynamicSection [ (26 entries)
 ELF-MIPS-EXE:   Tag        Type                 Name/Value
-ELF-MIPS-EXE:   0x00000001 NEEDED               SharedLibrary (libc.so.6)
+ELF-MIPS-EXE:   0x00000001 NEEDED               Shared library: [libc.so.6]
 ELF-MIPS-EXE:   0x0000000C INIT                 0x400418
 ELF-MIPS-EXE:   0x0000000D FINI                 0x4007B0
 ELF-MIPS-EXE:   0x00000004 HASH                 0x4002B8
 ELF-MIPS-EXE:   0x00000005 STRTAB               0x40036C
 ELF-MIPS-EXE:   0x00000006 SYMTAB               0x4002EC
 ELF-MIPS-EXE:   0x0000000A STRSZ                107 (bytes)
 ELF-MIPS-EXE:   0x0000000B SYMENT               16 (bytes)
 ELF-MIPS-EXE:   0x70000016 MIPS_RLD_MAP         0x410880

 RUN:     | FileCheck %s -check-prefix ELF-X86-EXE
 
 ELF-X86-EXE: Format: ELF32-i386
 ELF-X86-EXE: Arch: i386
 ELF-X86-EXE: AddressSize: 32bit
 ELF-X86-EXE: LoadName:
 ELF-X86-EXE: DynamicSection [ (30 entries)
 ELF-X86-EXE:   Tag        Type                 Name/Value
-ELF-X86-EXE:   0x00000001 NEEDED               SharedLibrary (libstdc++.so.6)
-ELF-X86-EXE:   0x00000001 NEEDED               SharedLibrary (libgcc_s.so.1)
-ELF-X86-EXE:   0x00000001 NEEDED               SharedLibrary (libc.so.6)
+ELF-X86-EXE:   0x00000001 NEEDED               Shared library: [libstdc++.so.6]
+ELF-X86-EXE:   0x00000001 NEEDED               Shared library: [libgcc_s.so.1]
+ELF-X86-EXE:   0x00000001 NEEDED               Shared library: [libc.so.6]
 ELF-X86-EXE:   0x0000000C INIT                 0x62C
 ELF-X86-EXE:   0x0000000D FINI                 0x920
 ELF-X86-EXE:   0x00000019 INIT_ARRAY           0x19FC
 ELF-X86-EXE:   0x0000001B INIT_ARRAYSZ         4 (bytes)
 ELF-X86-EXE:   0x0000001A FINI_ARRAY           0x1A00
 ELF-X86-EXE:   0x0000001C FINI_ARRAYSZ         4 (bytes)
 ELF-X86-EXE:   0x00000004 HASH                 0x18C
 ELF-X86-EXE:   0x6FFFFEF5 GNU_HASH             0x1E4

 
 RUN: llvm-readobj -dynamic-table %p/Inputs/dynamic-table-so.x86 \
 RUN:     | FileCheck %s -check-prefix ELF-X86-SO
 
 ELF-X86-SO: Format: ELF64-x86-64
 ELF-X86-SO: Arch: x86_64
 ELF-X86-SO: AddressSize: 64bit
 ELF-X86-SO: LoadName: 
-ELF-X86-SO: DynamicSection [ (26 entries)
+ELF-X86-SO: DynamicSection [ ({{[0-9]+}} entries)
 ELF-X86-SO:   Tag                Type                 Name/Value
-ELF-X86-SO:   0x0000000000000001 NEEDED               SharedLibrary (libc.so.6)
-ELF-X86-SO:   0x0000000000000001 NEEDED               SharedLibrary (ld-linux-x86-64.so.2)
-ELF-X86-SO:   0x000000007FFFFFFD AUXILIARY            Auxiliary library: [aux_val]
-ELF-X86-SO:   0x000000000000000C INIT                 0x610
-ELF-X86-SO:   0x000000000000000D FINI                 0x7AC
-ELF-X86-SO:   0x0000000000000019 INIT_ARRAY           0x200DD0
+ELF-X86-SO:   0x0000000000000001 NEEDED               Shared library: [libc.so.6]
+ELF-X86-SO:   0x0000000000000001 NEEDED               Shared library: [ld-linux-x86-64.so.2]
+ELF-X86-SO:   0x000000007FFFFFFF FILTER               Filter library: [filter.so]
+ELF-X86-SO:   0x000000007FFFFFFD AUXILIARY            Auxiliary library: [aux.so]
+ELF-X86-SO:   0x000000000000000C INIT                 0x{{[0-9A-F]+}}
+ELF-X86-SO:   0x000000000000000D FINI                 0x{{[0-9A-F]+}}
+ELF-X86-SO:   0x0000000000000019 INIT_ARRAY           0x{{[0-9A-F]+}}
 ELF-X86-SO:   0x000000000000001B INIT_ARRAYSZ         8 (bytes)
-ELF-X86-SO:   0x000000000000001A FINI_ARRAY           0x200DD8
+ELF-X86-SO:   0x000000000000001A FINI_ARRAY           0x{{[0-9A-F]+}}
 ELF-X86-SO:   0x000000000000001C FINI_ARRAYSZ         8 (bytes)
 ELF-X86-SO:   0x000000006FFFFEF5 GNU_HASH             0x1C8
 ELF-X86-SO:   0x0000000000000005 STRTAB               0x3A0
 ELF-X86-SO:   0x0000000000000006 SYMTAB               0x208
-ELF-X86-SO:   0x000000000000000A STRSZ                231 (bytes)
+ELF-X86-SO:   0x000000000000000A STRSZ                {{[0-9]+}} (bytes)
 ELF-X86-SO:   0x000000000000000B SYMENT               24 (bytes)
 ELF-X86-SO:   0x0000000000000003 PLTGOT               0x201000
 ELF-X86-SO:   0x0000000000000002 PLTRELSZ             48 (bytes)
 ELF-X86-SO:   0x0000000000000014 PLTREL               RELA
-ELF-X86-SO:   0x0000000000000017 JMPREL               0x5E0
-ELF-X86-SO:   0x0000000000000007 RELA                 0x4F0
+ELF-X86-SO:   0x0000000000000017 JMPREL               0x{{[0-9A-F]+}}
+ELF-X86-SO:   0x0000000000000007 RELA                 0x{{[0-9A-F]+}}
 ELF-X86-SO:   0x0000000000000008 RELASZ               240 (bytes)
 ELF-X86-SO:   0x0000000000000009 RELAENT              24 (bytes)
-ELF-X86-SO:   0x000000006FFFFFFE VERNEED              0x4B0
+ELF-X86-SO:   0x000000006FFFFFFE VERNEED              0x{{[0-9A-F]+}}
 ELF-X86-SO:   0x000000006FFFFFFF VERNEEDNUM           2
-ELF-X86-SO:   0x000000006FFFFFF0 VERSYM               0x488
+ELF-X86-SO:   0x000000006FFFFFF0 VERSYM               0x{{[0-9A-F]+}}
 ELF-X86-SO:   0x000000006FFFFFF9 RELACOUNT            3
 ELF-X86-SO:   0x0000000000000000 NULL                 0x0
 
 RUN: llvm-readobj -dynamic-table %p/Inputs/dynamic-table-so.aarch64 \
 RUN:     | FileCheck %s -check-prefix ELF-AARCH64-SO
 
 ELF-AARCH64-SO: Format: ELF64-aarch64-little
 ELF-AARCH64-SO: Arch: aarch64
 ELF-AARCH64-SO: AddressSize: 64bit
 ELF-AARCH64-SO: LoadName: 
 ELF-AARCH64-SO: DynamicSection [ (26 entries)
 ELF-AARCH64-SO:   Tag                Type                 Name/Value
-ELF-AARCH64-SO:   0x0000000000000001 NEEDED               SharedLibrary (libc.so.6)
+ELF-AARCH64-SO:   0x0000000000000001 NEEDED               Shared library: [libc.so.6]
 ELF-AARCH64-SO:   0x000000000000000C INIT                 0x660
 ELF-AARCH64-SO:   0x000000000000000D FINI                 0x83C
 ELF-AARCH64-SO:   0x0000000000000019 INIT_ARRAY           0x10DB8
 ELF-AARCH64-SO:   0x000000000000001B INIT_ARRAYSZ         8 (bytes)
 ELF-AARCH64-SO:   0x000000000000001A FINI_ARRAY           0x10DC0
 ELF-AARCH64-SO:   0x000000000000001C FINI_ARRAYSZ         8 (bytes)
 ELF-AARCH64-SO:   0x000000006FFFFEF5 GNU_HASH             0x1F0
 ELF-AARCH64-SO:   0x0000000000000005 STRTAB               0x420

tools/llvm-readobj/ELFDumper.cpp

static const char *getTypeString(unsigned Arch, uint64_t Type) {
   LLVM_READOBJ_TYPE_CASE(VERNEEDNUM);
   LLVM_READOBJ_TYPE_CASE(VERSYM);
   LLVM_READOBJ_TYPE_CASE(RELACOUNT);
   LLVM_READOBJ_TYPE_CASE(RELCOUNT);
   LLVM_READOBJ_TYPE_CASE(GNU_HASH);
   LLVM_READOBJ_TYPE_CASE(TLSDESC_PLT);
   LLVM_READOBJ_TYPE_CASE(TLSDESC_GOT);
   LLVM_READOBJ_TYPE_CASE(AUXILIARY);
+  LLVM_READOBJ_TYPE_CASE(FILTER);
   default: return "unknown";
   }
 }
 
 #undef LLVM_READOBJ_TYPE_CASE
 
 #define LLVM_READOBJ_DT_FLAG_ENT(prefix, enum) \
   { #enum, prefix##_##enum }

 
 template <class ELFT>
 StringRef ELFDumper<ELFT>::getDynamicString(uint64_t Value) const {
   if (Value >= DynamicStringTable.size())
     reportError("Invalid dynamic string table reference");
   return StringRef(DynamicStringTable.data() + Value);
 }
 
+static void printLibrary(raw_ostream &OS, const Twine &Tag, const Twine &Name) {
+  OS << Tag << ": [" << Name << "]";
+}
+
 template <class ELFT>
 void ELFDumper<ELFT>::printValue(uint64_t Type, uint64_t Value) {
   raw_ostream &OS = W.getOStream();
   const char* ConvChar = (opts::Output == opts::GNU) ? "0x%" PRIx64 : "0x%" PRIX64;
   switch (Type) {
   case DT_PLTREL:
     if (Value == DT_REL) {
       OS << "REL";
void ELFDumper<ELFT>::printValue(uint64_t Type, uint64_t Value) {
   case DT_RELSZ:
   case DT_RELENT:
   case DT_INIT_ARRAYSZ:
   case DT_FINI_ARRAYSZ:
   case DT_PREINIT_ARRAYSZ:
     OS << Value << " (bytes)";
     break;
   case DT_NEEDED:
-    OS << "SharedLibrary (" << getDynamicString(Value) << ")";
+    printLibrary(OS, "Shared library", getDynamicString(Value));
     break;
   case DT_SONAME:
-    OS << "LibrarySoname (" << getDynamicString(Value) << ")";
+    printLibrary(OS, "Library soname", getDynamicString(Value));
     break;
   case DT_AUXILIARY:
-    OS << "Auxiliary library: [" << getDynamicString(Value) << "]";
+    printLibrary(OS, "Auxiliary library", getDynamicString(Value));
+    break;
+  case DT_FILTER:
+    printLibrary(OS, "Filter library", getDynamicString(Value));
     break;
   case DT_RPATH:
   case DT_RUNPATH:
     OS << getDynamicString(Value);
     break;
   case DT_MIPS_FLAGS:
     printFlags(Value, makeArrayRef(ElfDynamicDTMipsFlags), OS);
     break;