[llvm-ar] Parse 'h' and '-h': display help and exit

[MaskRay]

Summary

Operation 'h' is undocumented in GNU ar. llvm-ar h or llvm-ar -h may
be what users try at first if they have the impression that operations
are usually not prepended by a dash.

[grimar]

tools/llvm-ar/llvm-ar.cpp

79 ↗

(On Diff #220121)

Should it be updated?

289 ↗

(On Diff #220121)

Shouldn't it be in handleGenericOption together with another -help-like things?

[MaskRay]

Parse -h (supported by GNU ar as well)
Address review comments

[jhenderson]

Operation 'h' is undocumented in GNU as.

I think you mean GNU ar... :)

No additional comments from me. Thanks!

[jhenderson]

LGTM.

llvm/trunk/test/tools/llvm-ar/help-message.test

+# RUN: llvm-ar h | FileCheck %s
+# RUN: llvm-ar -h | FileCheck %s
+# RUN: llvm-ar -help | FileCheck %s
+# RUN: llvm-ar --help | FileCheck %s
+
+# CHECK: USAGE: llvm-ar

llvm/trunk/tools/llvm-ar/llvm-ar.cpp

 
 const char ArHelp[] = R"(
 OVERVIEW: LLVM Archiver
 
 USAGE: llvm-ar [options] [-]<operation>[modifiers] [relpos] [count] <archive> [files]
        llvm-ar -M [<mri-script]
 
 OPTIONS:
-  --format              - Archive format to create
+  --format              - archive format to create
     =default            -   default
     =gnu                -   gnu
     =darwin             -   darwin
     =bsd                -   bsd
-  --plugin=<string>     - Ignored for compatibility
-  --help                - Display available options
-  --version             - Display the version of this program
+  --plugin=<string>     - ignored for compatibility
+  -h --help             - display this help and exit
+  --version             - print the version and exit
   @<file>               - read options from <file>
 
 OPERATIONS:
   d - delete [files] from the archive
   m - move [files] in the archive
   p - print [files] found in the archive
   q - quick append [files] to the archive
   r - replace or insert [files] into the archive
static void runMRIScript() {
 
   // Nothing to do if not saved.
   if (Saved)
     performOperation(ReplaceOrInsert, &NewMembers);
   exit(0);
 }
 
 static bool handleGenericOption(StringRef arg) {
-  if (arg == "-help" || arg == "--help") {
+  if (arg == "h" || arg.startswith("-h") || arg == "--help") {
     printHelpMessage();
     return true;
   }
   if (arg == "-version" || arg == "--version") {
     cl::PrintVersionMessage();
     return true;
   }
   return false;