nm: use -U as an alias for --defines-only, in line with llvm-nm

binutils/doc/binutils.texi

@@ -817,10 +817,9 @@ nm [@option{-A}|@option{-o}|@option{--print-file-name}]
    [@option{-s}|@option{--print-armap}]
    [@option{-t} @var{radix}|@option{--radix=}@var{radix}]
    [@option{-u}|@option{--undefined-only}]
-   [@option{-U} @var{method}] [@option{--unicode=}@var{method}]
+   [@option{-U}|@option{--defined-only}]
    [@option{-V}|@option{--version}]
    [@option{-X 32_64}]
-   [@option{--defined-only}]
    [@option{--no-demangle}]
    [@option{--no-recurse-limit}|@option{--recurse-limit}]]
    [@option{--plugin} @var{name}]
@@ -828,6 +827,7 @@ nm [@option{-A}|@option{-o}|@option{--print-file-name}]
    [@option{--special-syms}]
    [@option{--synthetic}]
    [@option{--target=}@var{bfdname}]
+   [@option{--unicode=}@var{method}]
    [@option{--with-symbol-versions}]
    [@option{--without-symbol-versions}]
    [@var{objfile}@dots{}]
@@ -1137,21 +1137,14 @@ Use @var{radix} as the radix for printing the symbol values.  It must be
 @cindex external symbols
 @cindex undefined symbols
 Display only undefined symbols (those external to each object file).
+By default both defined and undefined symbols are displayed.
 
-@item -U @var{[d|i|l|e|x|h]}
-@itemx --unicode=@var{[default|invalid|locale|escape|hex|highlight]}
-Controls the display of UTF-8 encoded multibyte characters in strings.
-The default (@option{--unicode=default}) is to give them no special
-treatment.  The @option{--unicode=locale} option displays the sequence
-in the current locale, which may or may not support them.  The options
-@option{--unicode=hex} and @option{--unicode=invalid} display them as
-hex byte sequences enclosed by either angle brackets or curly braces.
-
-The @option{--unicode=escape} option displays them as escape sequences
-(@var{\uxxxx}) and the @option{--unicode=highlight} option displays
-them as escape sequences highlighted in red (if supported by the
-output device).  The colouring is intended to draw attention to the
-presence of unicode sequences where they might not be expected.
+@item -U
+@itemx --defined-only
+@cindex external symbols
+@cindex undefined symbols
+Display only defined symbols for each object file.
+By default both defined and undefined symbols are displayed.
 
 @item -V
 @itemx --version
@@ -1163,11 +1156,6 @@ This option is ignored for compatibility with the AIX version of
 @option{32_64}.  The default mode of AIX @command{nm} corresponds
 to @option{-X 32}, which is not supported by @sc{gnu} @command{nm}.
 
-@item --defined-only
-@cindex external symbols
-@cindex undefined symbols
-Display only defined symbols for each object file.
-
 @item --plugin @var{name}
 @cindex plugins
 Load the plugin called @var{name} to add support for extra target
@@ -1196,6 +1184,9 @@ with the next higher value.  If the @code{bsd} output format is used
 the size of the symbol is printed, rather than the value, and
 @samp{-S} must be used in order both size and value to be printed.
 
+Note - this option does not work if @option{--undefined-only} has been
+enabled as undefined symbols have no size.
+
 @item --special-syms
 Display symbols which have a target-specific special meaning.  These
 symbols are usually used by the target for some special processing and
@@ -1208,6 +1199,20 @@ Include synthetic symbols in the output.  These are special symbols
 created by the linker for various purposes.  They are not shown by
 default since they are not part of the binary's original source code.
 
+@item --unicode=@var{[default|invalid|locale|escape|hex|highlight]}
+Controls the display of UTF-8 encoded multibyte characters in strings.
+The default (@option{--unicode=default}) is to give them no special
+treatment.  The @option{--unicode=locale} option displays the sequence
+in the current locale, which may or may not support them.  The options
+@option{--unicode=hex} and @option{--unicode=invalid} display them as
+hex byte sequences enclosed by either angle brackets or curly braces.
+
+The @option{--unicode=escape} option displays them as escape sequences
+(@var{\uxxxx}) and the @option{--unicode=highlight} option displays
+them as escape sequences highlighted in red (if supported by the
+output device).  The colouring is intended to draw attention to the
+presence of unicode sequences where they might not be expected.
+
 @item --with-symbol-versions
 @item --without-symbol-versions
 Enables or disables the display of symbol version information.  The

binutils/nm.c

@@ -242,6 +242,7 @@ enum long_option_values
   OPTION_RECURSE_LIMIT,
   OPTION_NO_RECURSE_LIMIT,
   OPTION_IFUNC_CHARS,
+  OPTION_UNICODE,
   OPTION_QUIET
 };
 
@@ -276,9 +277,9 @@ static struct option long_options[] =
   {"special-syms", no_argument, &allow_special_symbols, 1},
   {"synthetic", no_argument, &show_synthetic, 1},
   {"target", required_argument, 0, OPTION_TARGET},
-  {"defined-only", no_argument, &defined_only, 1},
-  {"undefined-only", no_argument, &undefined_only, 1},
-  {"unicode", required_argument, NULL, 'U'},
+  {"defined-only", no_argument, 0, 'U'},
+  {"undefined-only", no_argument, 0, 'u'},
+  {"unicode", required_argument, NULL, OPTION_UNICODE},
   {"version", no_argument, &show_version, 1},
   {"with-symbol-versions", no_argument, &with_symbol_versions, 1},
   {"without-symbol-versions", no_argument, &with_symbol_versions, 0},
@@ -311,8 +312,6 @@ usage (FILE *stream, int status)
       --no-recurse-limit Disable a demangling recursion limit.\n"));
   fprintf (stream, _("\
   -D, --dynamic          Display dynamic symbols instead of normal symbols\n"));
-  fprintf (stream, _("\
-      --defined-only     Display only defined symbols\n"));
   fprintf (stream, _("\
   -e                     (ignored)\n"));
   fprintf (stream, _("\
@@ -361,8 +360,10 @@ usage (FILE *stream, int status)
   fprintf (stream, _("\
   -u, --undefined-only   Display only undefined symbols\n"));
   fprintf (stream, _("\
-  -U {d|s|i|x|e|h}       Specify how to treat UTF-8 encoded unicode characters\n\
-      --unicode={default|show|invalid|hex|escape|highlight}\n"));
+  -U, --defined-only     Display only defined symbols\n"));
+  fprintf (stream, _("\
+      --unicode={default|show|invalid|hex|escape|highlight}\n\
+                         Specify how to treat UTF-8 encoded unicode characters\n"));
   fprintf (stream, _("\
       --with-symbol-versions  Display version strings after symbol names\n"));
   fprintf (stream, _("\
@@ -2143,9 +2144,14 @@ main (int argc, char **argv)
 	  break;
 	case 'u':
 	  undefined_only = 1;
+	  defined_only = 0;
+	  break;
+	case 'U':
+	  defined_only = 1;
+	  undefined_only = 0;
 	  break;
 
-	case 'U':
+	case OPTION_UNICODE:
 	  if (streq (optarg, "default") || streq (optarg, "d"))
 	    unicode_display = unicode_default;
 	  else if (streq (optarg, "locale") || streq (optarg, "l"))