[llvm-objdump] Fix --prefix and --prefix-strip

[gbreynoo]

Summary

In the command guide --prefix and --prefix-strip is used in the form --prefix=<prefix> however currently it is used in the form --prefix <prefix>. This change fixes these options to match the command guide.

[gbreynoo]

Looking at the other options in llvm-objdump, --option=<value> seems to be the consistent format. For this reason I changed the command line option rather than the user guide, if people disagree I'm happy to change the command guide instead.

[jhenderson]

What does GNU objdump allow? We should allow whatever GNU does.

[gbreynoo]

Fixed non windows test.

[gbreynoo]

Looking at the GNU docs its` --prefix=prefix`.

[MaskRay]

Many utilities supporting double-dash long options (not only GNU's) generally use the GNU style getopt_long which supports both --foo value and --foo=value.

We can use lld/llvm-objcopy style tablegen Eq to support both Joined and Separate.

[gbreynoo]

Updated after Maskray's comment.

[MaskRay]

I suggest that you use a multiclass Eq to avoid verbosity for individual options.

[gbreynoo]

Updated after Maskray's comment.

Thanks Maskray, that is cleaner.

[jhenderson]

LGTM! Please wait for @MaskRay too.

[MaskRay]

Thanks! Sorry for the slow response. I was out of town for one week.

llvm/test/tools/llvm-objdump/X86/source-interleave-prefix.test

 ; RUN: not llvm-objdump --prefix %p --prefix-strip '-1' --source %t-missing-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-INVALID-PREFIX-STRIP -DOPTION='-1'
 ; CHECK-INVALID-PREFIX-STRIP: {{.*}}llvm-objdump{{.*}}: error: --prefix-strip: expected a non-negative integer, but got '[[OPTION]]'
 
 ;; Test text value --prefix-strip. Reports an error.
 
 ; RUN: not llvm-objdump --prefix %p --prefix-strip foo --source %t-missing-prefix.o 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=CHECK-INVALID-PREFIX-STRIP -DOPTION='foo'
+
+;; Test use of --prefix= and --prefix-strip=
+
+; RUN: sed -e "s,SRC_COMPDIR,/extra/Inputs,g" %p/Inputs/source-interleave.ll > %t-extra-path-prefix.ll
+; RUN: llc -o %t-extra-path-prefix.o -filetype=obj -mtriple=x86_64-pc-linux %t-extra-path-prefix.ll
+; RUN: llvm-objdump --prefix=%p --prefix-strip=1 --source %t-extra-path-prefix.o 2>&1 | \
+; RUN:   FileCheck %s --check-prefix=CHECK-MISSING-PREFIX-FIX

llvm/tools/llvm-objdump/ObjdumpOpts.td

 include "llvm/Option/OptParser.td"
 
+multiclass Eq<string name, string help> {
+  def NAME : Separate<["--"], name>;
+  def NAME #_eq : Joined<["--"], name #"=">,
+                  Alias<!cast<Separate>(NAME)>,
+                  HelpText<help>;
+}
+
 def help : Flag<["--"], "help">,
   HelpText<"Display available options (--help-hidden for more)">;
 
 def help_hidden : Flag<["--"], "help-hidden">,
   Flags<[HelpHidden]>,
   HelpText<"Display all available options">;
 
 def version : Flag<["--"], "version">,
def unwind_info : Flag<["--"], "unwind-info">,
   HelpText<"Display unwind information">;
 def : Flag<["-"], "u">, Alias<unwind_info>,
   HelpText<"Alias for --unwind-info">;
 
 def wide : Flag<["--"], "wide">,
   HelpText<"Ignored for compatibility with GNU objdump">;
 def : Flag<["-"], "w">, Alias<wide>;
 
-def prefix : Separate<["--"], "prefix">,
-  HelpText<"Add prefix to absolute paths">;
-
-def prefix_strip : Separate<["--"], "prefix-strip">,
-  HelpText<"Strip out initial directories from absolute "
-           "paths. No effect without --prefix">;
+defm prefix : Eq<"prefix", "Add prefix to absolute paths">,
+              MetaVarName<"prefix">;
+defm prefix_strip
+    : Eq<"prefix-strip", "Strip out initial directories from absolute "
+                         "paths. No effect without --prefix">,
+      MetaVarName<"prefix">;
 
 def debug_vars_EQ : Joined<["--"], "debug-vars=">,
   Values<"unicode,ascii">;
 def : Flag<["--"], "debug-vars">,
   HelpText<"Print the locations (in registers or memory) of "
            "source-level variables alongside disassembly">,
   Alias<debug_vars_EQ>, AliasArgs<["unicode"]>;