[llvm-nm] Remove one-dash long options except -arch

[MaskRay]

Summary

The documentation and help messages have recommended the double-dash forms for
quite a while. Remove one-dash long options which are not recognized by GNU
style getopt_long.

-arch is kept as it is in the manpage of classic nm
https://keith.github.io/xcode-man-pages/nm.1.html

Note: the dyldinfo related options don't have a test.

[jhenderson]

LGTM. Is there a test-case that uses -arch with only a single dash? Since that's a special case, we might want to test it explicitly.

[MaskRay]

test/Object/AArch64/nm-trivial-object-arm64_32.test is such a test. Older llvm-nm/llvm-readobj/llvm-objdump Mach-O code has some tests under test/Object but some functionality does not have tests.

llvm/test/tools/llvm-nm/X86/posix-aliases.test

 # RUN: llvm-nm -P %p/Inputs/hello.obj.elf-x86_64 > %t1
 # RUN: llvm-nm --format=posix %p/Inputs/hello.obj.elf-x86_64 > %t2
-# RUN: llvm-nm -portability %p/Inputs/hello.obj.elf-x86_64 > %t3
+# RUN: llvm-nm --portability %p/Inputs/hello.obj.elf-x86_64 > %t3
 # RUN: diff %t1 %t2
 # RUN: diff %t1 %t3

llvm/tools/llvm-nm/Opts.td

 include "llvm/Option/OptParser.td"
 
 class F<string letter, string help> : Flag<["-"], letter>, HelpText<help>;
-class FF<string name, string help> : Flag<["--", "-"], name>, HelpText<help>;
+class FF<string name, string help> : Flag<["--"], name>, HelpText<help>;
 
 multiclass BB<string name, string help1, string help2> {
-  def NAME: Flag<["--", "-"], name>, HelpText<help1>;
-  def no_ # NAME: Flag<["--", "-"], "no-" # name>, HelpText<help2>;
+  def NAME: Flag<["--"], name>, HelpText<help1>;
+  def no_ # NAME: Flag<["--"], "no-" # name>, HelpText<help2>;
 }
 
 multiclass Eq<string name, string help> {
-  def NAME #_EQ : Joined<["--", "-"], name #"=">,
-                  HelpText<help>;
-  def : Separate<["--", "-"], name>, Alias<!cast<Joined>(NAME #_EQ)>;
+  def NAME #_EQ : Joined<["--"], name #"=">, HelpText<help>;
+  def : Separate<["--"], name>, Alias<!cast<Joined>(NAME #_EQ)>;
 }
 
 def debug_syms : FF<"debug-syms", "Show all symbols, even debugger only">;
 def defined_only : FF<"defined-only", "Show only defined symbols">;
 defm demangle : BB<"demangle", "Demangle C++ symbol names", "Don't demangle symbol names">;
 def dynamic : FF<"dynamic", "Display dynamic symbols instead of normal symbols">;
 def extern_only : FF<"extern-only", "Show only external symbols">;
 defm format : Eq<"format", "Specify output format: bsd (default), posix, sysv, darwin, just-symbols">, MetaVarName<"<format>">;

 def version : FF<"version", "Display the version">;
 def without_aliases : FF<"without-aliases", "Exclude aliases from output">, Flags<[HelpHidden]>;
 
 // Mach-O specific options.
 def grp_mach_o : OptionGroup<"kind">, HelpText<"llvm-nm Mach-O Specific Options">;
 
 def add_dyldinfo : FF<"add-dyldinfo", "Add symbols from the dyldinfo not already in the symbol table">, Group<grp_mach_o>;
 def add_inlinedinfo : FF<"add-inlinedinfo", "Add symbols from the inlined libraries, TBD only">, Group<grp_mach_o>;
-defm arch : Eq<"arch", "architecture(s) from a Mach-O file to dump">, Group<grp_mach_o>;
+def arch_EQ : Joined<["--"], "arch=">, HelpText<"architecture(s) from a Mach-O file to dump">, Group<grp_mach_o>;
+def : Separate<["--", "-"], "arch">, Alias<arch_EQ>;
 def dyldinfo_only : FF<"dyldinfo-only", "Show only symbols from the dyldinfo">, Group<grp_mach_o>;
 def no_dyldinfo : FF<"no-dyldinfo", "Don't add any symbols from the dyldinfo">, Group<grp_mach_o>;
 def s : F<"s", "Dump only symbols from this segment and section name">, Group<grp_mach_o>;
 def x : F<"x", "Print symbol entry in hex">, Group<grp_mach_o>;
 
 def : FF<"just-symbol-name", "Alias for --format=just-symbols">, Alias<format_EQ>, AliasArgs<["just-symbols"]>, Flags<[HelpHidden]>;
 def : FF<"portability", "Alias for --format=posix">, Alias<format_EQ>, AliasArgs<["posix"]>;