[CommandLine] Enable Grouping for short options by default. Part 4 of 5

[hintonda]

Summary

This change enables cl::Grouping for short options --
options with names of a single character. This is consistent with GNU
getopt behavior.

[hintonda]

• Fix test error message.

[MaskRay]

Thank you for the patch series!

This is consistent with GNU getopt behavior.

This is not GNU specific :) It is POSIX Utility Syntax Guidelines 5 http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap12.html

[hintonda]

• Fix test.

[hintonda]

Minimize diff.

[hintonda]

In D61270#1483661, @MaskRay wrote:

Thank you for the patch series!

This is consistent with GNU getopt behavior.

This is not GNU specific :) It is POSIX Utility Syntax Guidelines 5 http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap12.html

Thanks for pointing that out.

While not mentioned here, this series of patches also deals with long options which I believe is a GNU thing -- at least I think that's true. In any case, the ultimate goal of these patches is to allow GNU compatibility.

llvm/include/llvm/Support/CommandLine.h

template <> struct applicator<OptionHidden> {
   static void opt(OptionHidden OH, Option &O) { O.setHiddenFlag(OH); }
 };
 
 template <> struct applicator<FormattingFlags> {
   static void opt(FormattingFlags FF, Option &O) { O.setFormattingFlag(FF); }
 };
 
 template <> struct applicator<MiscFlags> {
-  static void opt(MiscFlags MF, Option &O) { O.setMiscFlag(MF); }
+  static void opt(MiscFlags MF, Option &O) {
+    assert((MF != Grouping || O.ArgStr.size() == 1) &&
+           "cl::Grouping can only apply to single charater Options.");
+    O.setMiscFlag(MF);
+  }
 };
 
 // apply method - Apply modifiers to an option in a type safe way.
 template <class Opt, class Mod, class... Mods>
 void apply(Opt *O, const Mod &M, const Mods &... Ms) {
   applicator<Mod>::opt(M, *O);
   apply(O, Ms...);
 }

llvm/lib/Support/CommandLine.cpp

 
 void Option::removeArgument() { GlobalParser->removeOption(this); }
 
 void Option::setArgStr(StringRef S) {
   if (FullyInitialized)
     GlobalParser->updateArgStr(this, S);
   assert((S.empty() || S[0] != '-') && "Option can't start with '-");
   ArgStr = S;
+  if (ArgStr.size() == 1)
+    setMiscFlag(Grouping);
 }
 
 void Option::reset() {
   NumOccurrences = 0;
   setDefault();
   if (isDefaultOption())
     removeArgument();
 }

llvm/test/tools/llvm-readobj/merged.test

 # Check merged args produce identical output to when not merged.
 RUN: llvm-readelf -aeWhSrnudlVgIs %p/Inputs/trivial.obj.elf-i386 > %t.merged
 RUN: llvm-readelf -a -e -W -h -S -r -n -u -d -l -V -g -I -s %p/Inputs/trivial.obj.elf-i386 > %t.not-merged
 RUN: cmp %t.merged %t.not-merged
 RUN: FileCheck %s --input-file %t.merged
 
 # llvm-readobj does not support merged args, because it also supports some old
 # flags (-st, -sd, etc.), and it would be confusing if only some merged args
 # were supported.
 RUN: not llvm-readobj -aeWhSrnudlVgIs %p/Inputs/trivial.obj.elf-i386 2>&1 | FileCheck %s --check-prefix=UNKNOWN
 
 CHECK-NOT: Unknown command line argument
-UNKNOWN:   Unknown command line argument
+UNKNOWN:   for the --section-headers option: may only occur zero or one times!