objcopy: Add --update-section option.

New option for objcopy --update-section allows the contents of a section
to be updated while maintaining the section flags, and, for ELF files,
the section to segment mapping.

New test uses --dump-section and --update-section to check that a
section can be made larger and smaller with an update.

binutils/ChangeLog:

	* objcopy.c (update_sections): New list.
	(command_line_switch): Add OPTION_UPDATE_SECTION.
	(copy_options): Add update-section.
	(copy_usage): Document new option.
	(is_update_section): New function.
	(is_strip_section_1): Add check for attempt to update and remove
	the same section.
	(copy_object): Update size and content of requested sections.
	(skip_section): Don't copy for updated sections.
	(copy_main): Handle --update-section.
	* doc/binutils.texi (objcopy): Add description of --update-section
	option.
	* NEWS: Mention --update-section option.

binutils/testsuite/ChangeLog:

	* binutils-all/update-1.s: New file.
	* binutils-all/update-2.s: New file.
	* binutils-all/update-3.s: New file.
	* binutils-all/update-4.s: New file.
	* binutils-all/update-section.exp: New file.

binutils/ChangeLog

@@ -1,3 +1,19 @@
+2015-02-28  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* objcopy.c (update_sections): New list.
+	(command_line_switch): Add OPTION_UPDATE_SECTION.
+	(copy_options): Add update-section.
+	(copy_usage): Document new option.
+	(is_update_section): New function.
+	(is_strip_section_1): Add check for attempt to update and remove
+	the same section.
+	(copy_object): Update size and content of requested sections.
+	(skip_section): Don't copy for updated sections.
+	(copy_main): Handle --update-section.
+	* doc/binutils.texi (objcopy): Add description of --update-section
+	option.
+	* NEWS: Mention --update-section option.
+
 2015-02-26  Nick Clifton  <nickc@redhat.com>
 
 	PR binutils/17512

binutils/NEWS

@@ -1,5 +1,7 @@
 -*- text -*-
 
+* Add --update-section option to objcopy.
+
 Changes in 2.25:
 
 * Add --data option to strings to only print strings in loadable, initialized

binutils/doc/binutils.texi

@@ -1091,6 +1091,7 @@ objcopy [@option{-F} @var{bfdname}|@option{--target=}@var{bfdname}]
         [@option{--set-section-flags} @var{sectionpattern}=@var{flags}]
         [@option{--add-section} @var{sectionname}=@var{filename}]
         [@option{--dump-section} @var{sectionname}=@var{filename}]
+        [@option{--update-section} @var{sectionname}=@var{filename}]
         [@option{--rename-section} @var{oldname}=@var{newname}[,@var{flags}]]
         [@option{--long-section-names} @{enable,disable,keep@}]
         [@option{--change-leading-char}] [@option{--remove-leading-char}]
@@ -1489,6 +1490,21 @@ that it does not create a formatted file, it just dumps the contents
 as raw binary data, without applying any relocations.  The option can
 be specified more than once.
 
+@item --update-section @var{sectionname}=@var{filename}
+Replace the existing contents of a section named @var{sectionname}
+with the contents of file @var{filename}.  The size of the section
+will be adjusted to the size of the file.  The section flags for
+@var{sectionname} will be unchanged.  For ELF format files the section
+to segment mapping will also remain unchanged, something which is not
+possible using @option{--remove-section} followed by
+@option{--add-section}.  The option can be specified more than once.
+
+Note - it is possible to use @option{--rename-section} and
+@option{--update-section} to both update and rename a section from one
+command line.  In this case, pass the original section name to
+@option{--update-section}, and the original and new section names to
+@option{--rename-section}.
+
 @item --rename-section @var{oldname}=@var{newname}[,@var{flags}]
 Rename a section from @var{oldname} to @var{newname}, optionally
 changing the section's flags to @var{flags} in the process.  This has

binutils/objcopy.c

@@ -186,6 +186,9 @@ struct section_add
 /* List of sections to add to the output BFD.  */
 static struct section_add *add_sections;
 
+/* List of sections to update in the output BFD.  */
+static struct section_add *update_sections;
+
 /* List of sections to dump from the output BFD.  */
 static struct section_add *dump_sections;
 
@@ -262,6 +265,7 @@ static enum long_section_name_handling long_section_names = KEEP;
 enum command_line_switch
   {
     OPTION_ADD_SECTION=150,
+    OPTION_UPDATE_SECTION,
     OPTION_DUMP_SECTION,
     OPTION_CHANGE_ADDRESSES,
     OPTION_CHANGE_LEADING_CHAR,
@@ -361,6 +365,7 @@ static struct option copy_options[] =
 {
   {"add-gnu-debuglink", required_argument, 0, OPTION_ADD_GNU_DEBUGLINK},
   {"add-section", required_argument, 0, OPTION_ADD_SECTION},
+  {"update-section", required_argument, 0, OPTION_UPDATE_SECTION},
   {"adjust-start", required_argument, 0, OPTION_CHANGE_START},
   {"adjust-vma", required_argument, 0, OPTION_CHANGE_ADDRESSES},
   {"adjust-section-vma", required_argument, 0, OPTION_CHANGE_SECTION_ADDRESS},
@@ -553,6 +558,9 @@ copy_usage (FILE *stream, int exit_status)
      --set-section-flags <name>=<flags>\n\
                                    Set section <name>'s properties to <flags>\n\
      --add-section <name>=<file>   Add section <name> found in <file> to output\n\
+     --update-section <name>=<file>\n\
+                                   Update contents of section <name> with\n\
+                                   contents found in <file>\n\
      --dump-section <name>=<file>  Dump the contents of section <name> into <file>\n\
      --rename-section <old>=<new>[,<flags>] Rename section <old> to <new>\n\
      --long-section-names {enable|disable|keep}\n\
@@ -1044,6 +1052,27 @@ is_dwo_section (bfd *abfd ATTRIBUTE_UNUSED, asection *sec)
   return strncmp (name + len - 4, ".dwo", 4) == 0;
 }
 
+/* Return TRUE if section SEC is in the update list.  */
+
+static bfd_boolean
+is_update_section (bfd *abfd ATTRIBUTE_UNUSED, asection *sec)
+{
+  if (update_sections != NULL)
+    {
+      struct section_add *pupdate;
+
+      for (pupdate = update_sections;
+           pupdate != NULL;
+           pupdate = pupdate->next)
+	{
+          if (strcmp (sec->name, pupdate->name) == 0)
+            return TRUE;
+        }
+    }
+
+  return FALSE;
+}
+
 /* See if a non-group section is being removed.  */
 
 static bfd_boolean
@@ -1062,6 +1091,9 @@ is_strip_section_1 (bfd *abfd ATTRIBUTE_UNUSED, asection *sec)
       if (p && q)
 	fatal (_("error: section %s matches both remove and copy options"),
 	       bfd_get_section_name (abfd, sec));
+      if (p && is_update_section (abfd, sec))
+        fatal (_("error: section %s matches both update and remove options"),
+               bfd_get_section_name (abfd, sec));
 
       if (p != NULL)
 	return TRUE;
@@ -1865,6 +1897,29 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
 	}
     }
 
+  if (update_sections != NULL)
+    {
+      struct section_add *pupdate;
+
+      for (pupdate = update_sections;
+	   pupdate != NULL;
+	   pupdate = pupdate->next)
+	{
+	  asection *osec;
+
+	  pupdate->section = bfd_get_section_by_name (ibfd, pupdate->name);
+	  if (pupdate->section == NULL)
+	    fatal (_("error: %s not found, can't be updated"), pupdate->name);
+
+	  osec = pupdate->section->output_section;
+	  if (! bfd_set_section_size (obfd, osec, pupdate->size))
+	    {
+	      bfd_nonfatal_message (NULL, obfd, osec, NULL);
+	      return FALSE;
+	    }
+	}
+    }
+
   if (dump_sections != NULL)
     {
       struct section_add * pdump;
@@ -2150,6 +2205,26 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
 	}
     }
 
+  if (update_sections != NULL)
+    {
+      struct section_add *pupdate;
+
+      for (pupdate = update_sections;
+           pupdate != NULL;
+           pupdate = pupdate->next)
+	{
+	  asection *osec;
+
+	  osec = pupdate->section->output_section;
+	  if (! bfd_set_section_contents (obfd, osec, pupdate->contents,
+	                                  0, pupdate->size))
+	    {
+	      bfd_nonfatal_message (NULL, obfd, osec, NULL);
+	      return FALSE;
+	    }
+	}
+    }
+
   if (gnu_debuglink_filename != NULL)
     {
       if (! bfd_fill_in_gnu_debuglink_section
@@ -2881,6 +2956,9 @@ skip_section (bfd *ibfd, sec_ptr isection)
   if (is_strip_section (ibfd, isection))
     return TRUE;
 
+  if (is_update_section (ibfd, isection))
+    return TRUE;
+
   flags = bfd_get_section_flags (ibfd, isection);
   if ((flags & SEC_GROUP) != 0)
     return TRUE;
@@ -3795,6 +3873,12 @@ copy_main (int argc, char *argv[])
           section_add_load_file (add_sections);
 	  break;
 
+	case OPTION_UPDATE_SECTION:
+	  update_sections = init_section_add (optarg, update_sections,
+                                              "--update-section");
+	  section_add_load_file (update_sections);
+	  break;
+
 	case OPTION_DUMP_SECTION:
           dump_sections = init_section_add (optarg, dump_sections,
                                             "--dump-section");

binutils/testsuite/ChangeLog

@@ -1,3 +1,11 @@
+2015-02-26  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* binutils-all/update-1.s: New file.
+	* binutils-all/update-2.s: New file.
+	* binutils-all/update-3.s: New file.
+	* binutils-all/update-4.s: New file.
+	* binutils-all/update-section.exp: New file.
+
 2015-02-24  Nick Clifton  <nickc@redhat.com>
 
 	* binutils-all/objcopy.exp: Skip the strip-10 test for the V850.

binutils/testsuite/binutils-all/update-1.s

@@ -0,0 +1,2 @@
+        .section ".foo", "aw"
+        .word 1, 1, 1, 1

binutils/testsuite/binutils-all/update-2.s

@@ -0,0 +1,2 @@
+        .section ".foo", "aw"
+        .word 2, 2, 2, 2, 2, 2

binutils/testsuite/binutils-all/update-3.s

@@ -0,0 +1,3 @@
+        .section ".foo", "aw"
+        .word 3, 3
+

binutils/testsuite/binutils-all/update-4.s

@@ -0,0 +1,2 @@
+        .section ".bar", "aw"
+        .word 5

binutils/testsuite/binutils-all/update-section.exp

@@ -0,0 +1,114 @@
+# Copyright (C) 2015 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
+
+if { [is_remote host] } then {
+    return
+}
+
+send_user "Version [binutil_version $OBJCOPY]"
+
+proc do_assemble {srcfile} {
+    global srcdir
+    global subdir
+    set objfile [regsub -- "\.s$" $srcfile ".o"]
+    if {![binutils_assemble $srcdir/$subdir/${srcfile} tmpdir/${objfile}]} then {
+        return 0;
+    }
+    return 1;
+}
+
+proc do_objcopy {objfile extraflags {pattern ""}} {
+    global OBJCOPY
+    global OBJCOPYFLAGS
+
+    set testname "objcopy $extraflags ${objfile}"
+    set got [binutils_run $OBJCOPY \
+                 "$OBJCOPYFLAGS ${extraflags} tmpdir/${objfile}"]
+    if ![regexp $pattern $got] then {
+        fail "objcopy ($testname)"
+        return 0
+    }
+    if { $pattern != "" } then {
+        pass "objcopy ($testname)"
+    }
+    return 1
+}
+
+proc do_compare {file1 file2} {
+    set src1 "tmpdir/${file1}"
+    set src2 "tmpdir/${file2}"
+    set status [remote_exec build cmp "${src1} ${src2}"]
+    set exec_output [lindex $status 1]
+    set exec_output [prune_warnings $exec_output]
+
+    set testname "compare ${file1} ${file2}"
+    if [string match "" $exec_output] then {
+        pass "objcopy ($testname)"
+    } else {
+        send_log "$exec_output\n"
+        verbose "$exec_output" 1
+        fail "objcopy ($testname)"
+        return 0
+    }
+    return 1
+}
+
+#
+# Start Of Tests
+#
+
+foreach f [list update-1.s update-2.s update-3.s update-4.s] {
+    if { ![do_assemble $f] } then {
+        unsupported "update-section.exp"
+        return
+    }
+}
+
+if { ![do_objcopy update-1.o \
+           "--dump-section .foo=tmpdir/dumped-contents"]
+     || ![do_objcopy update-2.o \
+              "--update-section .foo=tmpdir/dumped-contents"]
+     || ![do_objcopy update-3.o \
+              "--update-section .foo=tmpdir/dumped-contents"]
+     || ![do_objcopy update-4.o \
+              "--update-section .bar=tmpdir/dumped-contents \
+               --rename-section .bar=.foo"] } then {
+    # If any of the above tests failed then a FAIL will already have
+    # been reported.
+    return
+}
+
+# Check that the updated object files are as expected.
+do_compare update-1.o update-2.o
+do_compare update-1.o update-3.o
+do_compare update-1.o update-4.o
+
+# Check that --update-section on an unknown section will fail.
+if { ![do_objcopy update-2.o \
+           "--update-section .bar=tmpdir/dumped-contents" \
+           "error: .bar not found, can't be updated"] } then {
+    return
+}
+
+# Check that --update-section and --remove-section on the same section
+# will fail.
+if { ![do_objcopy update-2.o \
+           "--update-section .foo=tmpdir/dumped-contents \
+            --remove-section .foo" \
+           "error: section .foo matches both update and remove options"] \
+     } then {
+    return
+}