Add a --no-weak option to nm.

PR 29135
	* nm.c (non_weak): New variable.
	(filter_symbols): When non-weak is true, ignore weak symbols.
	(long_options): Add --no-weak.
	(usage): Mention --no-weak.
	(main): Handle -W/--no-weak.
	* doc/binutils.texi: Document new feature.
	* NEWS: Mention the new feature.
	* testsuite/binutils-all/nm.exp: Add test of new feature.
	* testsuite/binutils-all/no-weak.s: New test source file.

binutils/ChangeLog

@@ -1,3 +1,16 @@
+2022-05-18  Nick Clifton  <nickc@redhat.com>
+
+	PR 29135
+	* nm.c (non_weak): New variable.
+	(filter_symbols): When non-weak is true, ignore weak symbols.
+	(long_options): Add --no-weak.
+	(usage): Mention --no-weak.
+	(main): Handle -W/--no-weak.
+	* doc/binutils.texi: Document new feature.
+	* NEWS: Mention the new feature.
+	* testsuite/binutils-all/nm.exp: Add test of new feature.
+	* testsuite/binutils-all/no-weak.s: New test source file.
+
 2022-04-25  Nick Clifton  <nickc@redhat.com>
 
 	PR 29072

binutils/NEWS

@@ -1,7 +1,9 @@
 -*- text -*-
+* Add --no-weak/-W option to nm to make it ignore weak symbols.
 
 * Add an option to objdump and readelf to prevent attempts to access debuginfod
   servers when following links.
+
 * objcopy --weaken, --weaken-symbol, and --weaken-symbols now make ELF
   STB_GNU_UNIQUE symbols weak.
 

binutils/doc/binutils.texi

@@ -819,6 +819,7 @@ nm [@option{-A}|@option{-o}|@option{--print-file-name}]
    [@option{-u}|@option{--undefined-only}]
    [@option{-U}|@option{--defined-only}]
    [@option{-V}|@option{--version}]
+   [@option{-W}|@option{--no-weak}]
    [@option{-X 32_64}]
    [@option{--no-demangle}]
    [@option{--no-recurse-limit}|@option{--recurse-limit}]]
@@ -1213,6 +1214,10 @@ 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 -W
+@itemx --no-weak
+Do not display weak symbols.
+
 @item --with-symbol-versions
 @item --without-symbol-versions
 Enables or disables the display of symbol version information.  The

binutils/nm.c

@@ -176,6 +176,7 @@ static const char *print_format_string = NULL;
 static int do_demangle = 0;	/* Pretty print C++ symbol names.  */
 static int external_only = 0;	/* Print external symbols only.  */
 static int defined_only = 0;	/* Print defined symbols only.  */
+static int non_weak = 0;	/* Ignore weak symbols.  */
 static int no_sort = 0;		/* Don't sort; print syms in order found.  */
 static int print_debug_syms = 0;/* Print debugger-only symbols too.  */
 static int print_armap = 0;	/* Describe __.SYMDEF data in archive files.  */
@@ -281,6 +282,7 @@ static struct option long_options[] =
   {"undefined-only", no_argument, 0, 'u'},
   {"unicode", required_argument, NULL, OPTION_UNICODE},
   {"version", no_argument, &show_version, 1},
+  {"no-weak", no_argument, 0, 'W'},
   {"with-symbol-versions", no_argument, &with_symbol_versions, 1},
   {"without-symbol-versions", no_argument, &with_symbol_versions, 0},
   {0, no_argument, 0, 0}
@@ -364,6 +366,8 @@ usage (FILE *stream, int status)
   fprintf (stream, _("\
       --unicode={default|show|invalid|hex|escape|highlight}\n\
                          Specify how to treat UTF-8 encoded unicode characters\n"));
+  fprintf (stream, _("\
+  -W, --no-weak          Ignore weak symbols\n"));
   fprintf (stream, _("\
       --with-symbol-versions  Display version strings after symbol names\n"));
   fprintf (stream, _("\
@@ -808,6 +812,8 @@ filter_symbols (bfd *abfd, bool is_dynamic, void *minisyms,
 			       | BSF_GNU_UNIQUE)) != 0
 		|| bfd_is_und_section (sym->section)
 		|| bfd_is_com_section (sym->section));
+      else if (non_weak)
+	keep = ((sym->flags & BSF_WEAK) == 0);
       else
 	keep = 1;
 
@@ -2052,7 +2058,7 @@ main (int argc, char **argv)
     fatal (_("fatal error: libbfd ABI mismatch"));
   set_default_bfd_target ();
 
-  while ((c = getopt_long (argc, argv, "aABCDef:gHhjJlnopPrSst:uU:vVvX:",
+  while ((c = getopt_long (argc, argv, "aABCDef:gHhjJlnopPrSst:uU:vVvWX:",
 			   long_options, (int *) 0)) != EOF)
     {
       switch (c)
@@ -2171,6 +2177,9 @@ main (int argc, char **argv)
 	case 'V':
 	  show_version = 1;
 	  break;
+	case 'W':
+	  non_weak = 1;
+	  break;
 	case 'X':
 	  /* Ignored for (partial) AIX compatibility.  On AIX, the
 	     argument has values 32, 64, or 32_64, and specifies that

binutils/testsuite/binutils-all/nm.exp

@@ -340,7 +340,37 @@ if [is_elf_format] {
 	}
     }
 
+    set testname "nm --no-weak"
+    if {![binutils_assemble $srcdir/$subdir/no-weak.s tmpdir/no-weak.o]} then {
+	fail "$testname (assembly)"
+    } else {
+	if [is_remote host] {
+	    set tmpfile [remote_download host tmpdir/no-weak.o]
+	} else {
+	    set tmpfile tmpdir/no-weak.o
+	}
 
+	set got [binutils_run $NM "$NMFLAGS --no-weak $tmpfile"]
+
+	if [regexp "weak_with_default_value" $got] then {
+	    fail "$testname (weak symbol with default value)"
+	} else {
+	    pass "$testname (weak symbol with default value)"
+	}
+
+	if [regexp "weak_without_default_value" $got] then {
+	    fail "$testname (weak symbol without default value)"
+	} else {
+	    pass "$testname (weak symbol without default value)"
+	}
+
+	# FIXME: We should re run this test without the --no-weak option
+	# and verify that the expected symbol names *are* shown...
+
+	if { $verbose < 1 } {
+	    remote_file host delete "tmpdir/no0weak.o"
+	}
+    }    
 }
 
 # There are certainly other tests that could be run.

binutils/testsuite/binutils-all/no-weak.s

@@ -0,0 +1,13 @@
+	.file	"no-weak.c"
+	.text
+
+	.globl	weak_with_default_value
+	.weak   weak_with_default_value
+weak_with_default_value:	
+	.nop
+	
+	.data
+	.weak   weak_without_default_value
+	.dc.a   weak_without_default_value
+	
+