llvm-objdump: sort phdr strings and add PT_NOTE

[davide]

This can be probably separated in two commits, which sorts and the other one which adds PT_NOTE.
For 1), LGTM, and you can probably commit it as is. For 2), please add a test and I'll take another look.

[emaste]

For 2), please add a test and I'll take another look.

I couldn't find any existing examples of similar tests - we need a linked binary here so we have phdrs. Do you have any suggestions? We could make use of lld perhaps?

[davide]

In D28085#630627, @emaste wrote:

For 2), please add a test and I'll take another look.

I couldn't find any existing examples of similar tests - we need a linked binary here so we have phdrs. Do you have any suggestions? We could make use of lld perhaps?

I don't think it's reasonable to call lld in the test as it's a subproject and that would violate the property of llvm test suite being self-contained. When I had to deal with this in the past I checked in a binary or used yaml2obj to craft an object. If you go for 1) I recommend to add precise instructions on how you created the binary (i.e. source code + clang/lld invocation etc..)

[emaste]

In D28085#630631, @davide wrote:

When I had to deal with this in the past I checked in a binary or used yaml2obj to craft an object.

OK. yaml2obj can't create phdr entries so I'll see about crafting a small binary that could be checked in.

[davide]

PT_NOTE was implemented as r292170. You can probably rebase and sort the strings, still.

[emaste]

Sorting was committed in rL290494 and PT_LOAD in rL292170.

tools/llvm-objdump/ELFDump.cpp

template <class ELFT> void printProgramHeaders(const ELFFile<ELFT> *o) {
   typedef ELFFile<ELFT> ELFO;
   outs() << "Program Header:\n";
   auto ProgramHeaderOrError = o->program_headers();
   if (!ProgramHeaderOrError)
     report_fatal_error(
         errorToErrorCode(ProgramHeaderOrError.takeError()).message());
   for (const typename ELFO::Elf_Phdr &Phdr : *ProgramHeaderOrError) {
     switch (Phdr.p_type) {
-    case ELF::PT_LOAD:
-      outs() << "    LOAD ";
-      break;
-    case ELF::PT_GNU_STACK:
-      outs() << "   STACK ";
+    case ELF::PT_DYNAMIC:
+      outs() << " DYNAMIC ";
       break;
     case ELF::PT_GNU_EH_FRAME:
       outs() << "EH_FRAME ";
       break;
+    case ELF::PT_GNU_STACK:
+      outs() << "   STACK ";
+      break;
     case ELF::PT_INTERP:
       outs() << "  INTERP ";
       break;
-    case ELF::PT_DYNAMIC:
-      outs() << " DYNAMIC ";
+    case ELF::PT_LOAD:
+      outs() << "    LOAD ";
+      break;
+    case ELF::PT_NOTE:
+      outs() << "    NOTE ";
       break;
     case ELF::PT_PHDR:
       outs() << "    PHDR ";
       break;
     case ELF::PT_TLS:
       outs() << "    TLS ";
       break;
     default: