[llvm-objdump] - Change the output for --all-headers.

[grimar]

Summary

This is for https://bugs.llvm.org/show_bug.cgi?id=40008,

it starts printing the file headers when --all-headers is given and
do a few cosmetic changes.

[jhenderson]

tools/llvm-objdump/llvm-objdump.cpp

2304

Won't the extra '\n' result in a weird extra blank line when printing just the file headers?

I also noticed that there was a lot of inconsistency between the different outputs in this area. What I'd like to see is each different dump to append a blank line, only if there is more to come.

I don't feel too strongly about it though, as long as we are consistent.

[grimar]

tools/llvm-objdump/llvm-objdump.cpp

2304

With that change it becomes consistent with what is done for COFF:
https://github.com/llvm-mirror/llvm/blob/master/tools/llvm-objdump/llvm-objdump.cpp#L2437

It prints an additional empty line after "start address" but does not seem it look too bad perhaps:
(I mean the last extra line, the first one looks a bit wierd to me, but it was already there).

umb@umb-virtual-machine:~/LLVM$ /home/umb/LLVM/build/bin/llvm-objdump ooo --file-headers

ooo: file format ELF64-x86-64

architecture: x86_64
start address: 0x0000000000201000

umb@umb-virtual-machine:~/LLVM$ /home/umb/LLVM/build/bin/llvm-objdump ooo --section-headers

I am also noticed a few inconsistencies (and also code style issues), but I think it is better to fix/refactor in a separate patch(es),
all at once perhaps.

[jhenderson]

LGTM.

tools/llvm-objdump/llvm-objdump.cpp

2304

Okay, sounds reasonable.

test/tools/llvm-objdump/all-headers.test

+# RUN: yaml2obj %s > %t
+# RUN: llvm-objdump --all-headers %t | FileCheck %s
+
+## Check we print file format, architecture and start address before
+## anything else when using --all-headers.
+
+# CHECK:       file format ELF64-x86-64
+# CHECK-EMPTY:
+# CHECK-NEXT:  architecture: x86_64
+# CHECK-NEXT:  start address: 0x0000000000000000
+# CHECK-EMPTY:
+# CHECK-NEXT:  Sections:
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_EXEC
+  Machine:         EM_X86_64
+Sections:

tools/llvm-objdump/llvm-objdump.cpp

static void printFileHeaders(const ObjectFile *o) {
   outs() << "architecture: " << Triple::getArchTypeName(AT) << "\n";
   Expected<uint64_t> StartAddrOrErr = o->getStartAddress();
   if (!StartAddrOrErr)
     report_error(o->getFileName(), StartAddrOrErr.takeError());
 
   StringRef Fmt = o->getBytesInAddress() > 4 ? "%016" PRIx64 : "%08" PRIx64;
   uint64_t Address = StartAddrOrErr.get();
   outs() << "start address: "
-         << "0x" << format(Fmt.data(), Address)
-         << "\n";
+         << "0x" << format(Fmt.data(), Address) << "\n\n";
 }
 
 static void printArchiveChild(StringRef Filename, const Archive::Child &C) {
   Expected<sys::fs::perms> ModeOrErr = C.getAccessMode();
   if (!ModeOrErr) {
     WithColor::error(errs(), ToolName) << "ill-formed archive entry.\n";
     consumeError(ModeOrErr.takeError());
     return;
if (!RawClangAST) {
     outs() << '\n';
     if (a)
       outs() << a->getFileName() << "(" << o->getFileName() << ")";
     else
       outs() << o->getFileName();
     outs() << ":\tfile format " << o->getFileFormatName() << "\n\n";
   }
 
+  if (FileHeaders)
+    printFileHeaders(o);
   if (ArchiveHeaders && !MachOOpt && c)
     printArchiveChild(ArchiveName, *c);
   if (Disassemble)
     DisassembleObject(o, Relocations);
   if (Relocations && !Disassemble)
     PrintRelocations(o);
   if (DynamicRelocations)
     PrintDynamicRelocations(o);
   if (SectionHeaders)
     PrintSectionHeaders(o);
   if (SectionContents)
     PrintSectionContents(o);
   if (SymbolTable)
     PrintSymbolTable(o, ArchiveName);
   if (UnwindInfo)
     PrintUnwindInfo(o);
   if (PrivateHeaders || FirstPrivateHeader)
     printPrivateFileHeaders(o, FirstPrivateHeader);
-  if (FileHeaders)
-    printFileHeaders(o);
   if (ExportsTrie)
     printExportsTrie(o);
   if (Rebase)
     printRebaseTable(o);
   if (Bind)
     printBindTable(o);
   if (LazyBind)
     printLazyBindTable(o);
int main(int argc, char **argv) {
 
   ToolName = argv[0];
 
   // Defaults to a.out if no filenames specified.
   if (InputFilenames.empty())
     InputFilenames.push_back("a.out");
 
   if (AllHeaders)
-    PrivateHeaders = Relocations = SectionHeaders = SymbolTable = true;
+    FileHeaders = PrivateHeaders = Relocations = SectionHeaders = SymbolTable =
+        true;
 
   if (DisassembleAll || PrintSource || PrintLines)
     Disassemble = true;
 
   if (!Disassemble
       && !Relocations
       && !DynamicRelocations
       && !SectionHeaders