Change the readelf and objdump programs so that they will automatically follow links to separate debug info files.

	* configure.ac (follow-debug-links): Add option to enable or
	disable the following of debug links by default.  Set the
	default for the option to be 'follow'.
	* dwarf.c (do_follow_links): Initialise with DEFAULT_FOR_FOLLOW_LINKS.
	(dwarf_select_sections_by_names): Add no-follow-links option.
	(dwarf_select_sections_by_letter): Add 'N' option.
	* objdump.c (usage): Add conditional text describing the
	follow links option.
	(slurp_symtab): Ensure that there is a NULL entry at the end
	of the symbol table.
	(slurp_dynamic_symtab): Likewise.
	(dump_bfd): When extending the symbol table, ensure that there
	is still a NULL entry at the end.
	* readelf.c (usage): Add conditional text describing the
	follow links option.
	* doc/binutils.texi: Update documentation for objcopy and
	readelf.
	* doc/debug.options.texi: Update documentation of the
	follow-links option.
	* config.in: Regenerate.
	* configure: Regenerate.
	* testsuite/binutils-all/compress.exp: Add the -WN option to
	objdump command lines that are not expecting to follow links.
	* testsuite/binutils-all/readelf.exp: Add the
	--debug-dump=no-follow-links option to tests that are not
	expecting to follow debug links.

gas	* testsuite/gas/mach-o/sections-1.d: Stop automatic debug link
        following.
	* testsuite/gas/xgate/insns-dwarf2.d: Likewise.

ld	* testsuite/ld-elf/sec64k.exp: Stop readelf from automatically
	following debug links.

1 files changed, 10 insertions, 6 deletions

diff --git a/binutils/doc/binutils.texi b/binutils/doc/binutils.texi
index 526efe4..94ea572 100644
--- a/binutils/doc/binutils.texi
+++ b/binutils/doc/binutils.texi
@@ -2187,8 +2187,10 @@ objdump [@option{-a}|@option{--archive-headers}]
         [@option{-r}|@option{--reloc}]
         [@option{-R}|@option{--dynamic-reloc}]
         [@option{-s}|@option{--full-contents}]
-        [@option{-W[lLiaprmfFsoORtUuTgAckK]}|
-         @option{--dwarf}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]]
+        [@option{-W[lLiaprmfFsoORtUuTgAck]}|
+         @option{--dwarf}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links]]
+        [@option{-WK}|@option{--dwarf=follow-links}]
+        [@option{-WN}|@option{--dwarf=no-follow-links}]
         [@option{--ctf=}@var{section}]
         [@option{-G}|@option{--stabs}]
         [@option{-t}|@option{--syms}]
@@ -2325,7 +2327,7 @@ will stop at the end of the function, otherwise it will stop when the
 next symbol is encountered.  If there are no matches for @var{symbol}
 then nothing will be displayed.
 
-Note if the @option{--dwarf=follow-links} option has also been enabled
+Note if the @option{--dwarf=follow-links} option is enabled
 then any symbol tables in linked debug info files will be read in and
 used when disassembling.
 
@@ -2347,7 +2349,7 @@ If the target is an ARM architecture this switch also has the effect
 of forcing the disassembler to decode pieces of data found in code
 sections as if they were instructions.
 
-Note if the @option{--dwarf=follow-links} option has also been enabled
+Note if the @option{--dwarf=follow-links} option is enabled
 then any symbol tables in linked debug info files will be read in and
 used when disassembling.
 
@@ -4753,8 +4755,10 @@ readelf [@option{-a}|@option{--all}]
         [@option{-R} <number or name>|@option{--relocated-dump=}<number or name>]
         [@option{-z}|@option{--decompress}]
         [@option{-c}|@option{--archive-index}]
-        [@option{-w[lLiaprmfFsoORtUuTgAckK]}|
-         @option{--debug-dump}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]]
+        [@option{-w[lLiaprmfFsoORtUuTgAck]}|
+         @option{--debug-dump}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links]]
+        [@option{-wK}|@option{--debug-dump=follow-links}]
+        [@option{-wN}|@option{--debug-dump=no-follow-links}]
         [@option{--dwarf-depth=@var{n}}]
         [@option{--dwarf-start=@var{n}}]
         [@option{--ctf=}@var{section}]