Prevent the --keep-global-symbol and --globalize-symbol options from being used together.

This is the result of an email thread starting here:
  https://sourceware.org/ml/binutils/2018-09/msg00031.html

The main point of the thread is this observation:

  * Supposing we had an object file with two globals, SomeGlobal and
  SomeOtherGlobal, if one were to do "--globalize-symbol SomeGlobal
  --keep-global-symbol SomeOtherGlobal", you might expect that both
  SomeGlobal and SomeOtherGlobal are global in the output file... but it
  isn't. Because --keep-global-symbol is set and doesn't include
  SomeGlobal, SomeGlobal will be demoted to a local symbol. And because
  the check to see if we should apply the --globalize-symbol flag checks
  "flags" (the original flag set), and not "sym->flags", it decides not
  to do anything, so SomeGlobal remains a local symbol. Although this is
  a weird edge case, should this be changed so that --keep-global-symbol
  implicitly keeps anything also specified via --globalize-symbol? (The
  code seems technically correct with respect to the documentation, but
  IMO the behavior is counter-intuitive).

binutils* objcopy.c (copy_main): Issue a fata error if the
	--keep-global-symbol(s) and the --globalize-symbol(s) options are
	used together.
	* doc/binutils.texi: Document that the two options are
	incompatible.
	* testsuite/binutils-all/copy-5.d: New test.
	* testsuite/binutils-all/objcopy.exp: Run the new test.

binutils/ChangeLog

@@ -1,3 +1,14 @@
+2018-10-11  Jordan Rupprecht  <rupprecht@google.com>
+	    Nick Clifton  <nickc@redhat.com>
+
+	* objcopy.c (copy_main): Issue a fata error if the
+	--keep-global-symbol(s) and the --globalize-symbol(s) options are
+	used together.
+	* doc/binutils.texi: Document that the two options are
+	incompatible.
+	* testsuite/binutils-all/copy-5.d: New test.
+	* testsuite/binutils-all/objcopy.exp: Run the new test.
+
 2018-10-10  Helge Deller <deller@gmx.de>
 	    Alan Modra  <amodra@gmail.com>
 

binutils/doc/binutils.texi

@@ -1129,6 +1129,7 @@ objcopy [@option{-F} @var{bfdname}|@option{--target=}@var{bfdname}]
         [@option{--localize-hidden}]
         [@option{-L} @var{symbolname}|@option{--localize-symbol=}@var{symbolname}]
         [@option{--globalize-symbol=}@var{symbolname}]
+        [@option{--globalize-symbols=}@var{filename}]
         [@option{-W} @var{symbolname}|@option{--weaken-symbol=}@var{symbolname}]
         [@option{-w}|@option{--wildcard}]
         [@option{-x}|@option{--discard-all}]
@@ -1169,7 +1170,6 @@ objcopy [@option{-F} @var{bfdname}|@option{--target=}@var{bfdname}]
         [@option{--strip-unneeded-symbols=}@var{filename}]
         [@option{--keep-global-symbols=}@var{filename}]
         [@option{--localize-symbols=}@var{filename}]
-        [@option{--globalize-symbols=}@var{filename}]
         [@option{--weaken-symbols=}@var{filename}]
         [@option{--add-symbol} @var{name}=[@var{section}:]@var{value}[,@var{flags}]]
         [@option{--alt-machine-code=}@var{index}]
@@ -1380,7 +1380,9 @@ by a relocation.  This option may be given more than once.
 @itemx --keep-global-symbol=@var{symbolname}
 Keep only symbol @var{symbolname} global.  Make all other symbols local
 to the file, so that they are not visible externally.  This option may
-be given more than once.
+be given more than once.  Note: this option cannot be used in
+conjunction with the @option{--globalize-symbol} or
+@option{--globalize-symbols} options.
 
 @item --localize-hidden
 In an ELF object, mark all symbols that have hidden or internal visibility
@@ -1400,7 +1402,8 @@ Make symbol @var{symbolname} weak. This option may be given more than once.
 @item --globalize-symbol=@var{symbolname}
 Give symbol @var{symbolname} global scoping so that it is visible
 outside of the file in which it is defined.  This option may be given
-more than once.
+more than once.  Note: this option cannot be used in conjunction with
+the @option{-G} or @option{--keep-global-symbol} options.
 
 @item -w
 @itemx --wildcard
@@ -1774,7 +1777,9 @@ This option may be given more than once.
 Apply @option{--globalize-symbol} option to each symbol listed in the file
 @var{filename}.  @var{filename} is simply a flat file, with one symbol
 name per line.  Line comments may be introduced by the hash character.
-This option may be given more than once.
+This option may be given more than once.  Note: this option cannot be
+used in conjunction with the @option{-G} or @option{--keep-global-symbol}
+options.
 
 @item --weaken-symbols=@var{filename}
 Apply @option{--weaken-symbol} option to each symbol listed in the file

binutils/objcopy.c

@@ -4753,6 +4753,8 @@ copy_main (int argc, char *argv[])
   bfd_boolean show_version = FALSE;
   bfd_boolean change_warn = TRUE;
   bfd_boolean formats_info = FALSE;
+  bfd_boolean use_globalize = FALSE;
+  bfd_boolean use_keep_global = FALSE;
   int c;
   struct stat statbuf;
   const bfd_arch_info_type *input_arch = NULL;
@@ -4871,10 +4873,12 @@ copy_main (int argc, char *argv[])
 	  break;
 
 	case OPTION_GLOBALIZE_SYMBOL:
+	  use_globalize = TRUE;
 	  add_specific_symbol (optarg, globalize_specific_htab);
 	  break;
 
 	case 'G':
+	  use_keep_global = TRUE;
 	  add_specific_symbol (optarg, keepglobal_specific_htab);
 	  break;
 
@@ -5306,11 +5310,13 @@ copy_main (int argc, char *argv[])
 	  break;
 
 	case OPTION_GLOBALIZE_SYMBOLS:
+	  use_globalize = TRUE;
 	  add_specific_symbols (optarg, globalize_specific_htab,
 				&globalize_specific_buffer);
 	  break;
 
 	case OPTION_KEEPGLOBAL_SYMBOLS:
+	  use_keep_global = TRUE;
 	  add_specific_symbols (optarg, keepglobal_specific_htab,
 				&keepglobal_specific_buffer);
 	  break;
@@ -5446,6 +5452,9 @@ copy_main (int argc, char *argv[])
 	}
     }
 
+  if (use_globalize && use_keep_global)
+    fatal(_("--globalize-symbol(s) is incompatible with -G/--keep-global-symbol(s)"));
+
   if (formats_info)
     {
       display_info ();

binutils/testsuite/binutils-all/copy-5.d

@@ -0,0 +1,7 @@
+#PROG: objcopy
+#source: bintest.s
+#objcopy: -G fred --globalize-symbol jim bintest.o bintest.copy.o
+# A few targets cannot assemble the bintest.s source file...
+#notarget: pdp11-* *-darwin
+#name: Error when using --keep-global-symbol with --globalize-symbol
+#error: \A[^\n]*: --globalize-symbol\(s\) is incompatible with -G/--keep-global-symbol\(s\)

binutils/testsuite/binutils-all/objcopy.exp

@@ -1074,6 +1074,8 @@ if [is_elf_format] {
 run_dump_test "copy-2"
 run_dump_test "copy-3"
 run_dump_test "copy-4"
+run_dump_test "copy-5"
+
 # Use bintest.o from the copy-4 test to determine ELF reloc type
 set reloc_format rel
 if { [is_elf_format] && [is_rela tmpdir/bintest.o] } {