PR23611, objcopy is not removing executable relocatable sections

BFD handles ELF relocation sections in an executable differently to
relocation sections in a relocatable object.  For a relocatable
object, BFD carries the relocations as data associated with the
section to which they apply; The relocation section doesn't appear as
a separate section.  For an executable, dynamic relocation sections do
appear as separate sections.  This means that objcopy needs to use
different strategies when dealing with relocations.

When --remove-relocations was added to objcopy with commit
d3e5f6c8f1e, objcopy lost the ability to remove dynamic relocation
sections such as .rela.plt from executables using the option
"--remove-section=.rela.plt".  This patch reinstates that
functionality.

I thought it best to keep --remove-relocations as is, rather than
extending to handle dynamic relocations as per the patch in the PR,
because executables linked with --emit-relocs may have both dynamic
and non-dynamic relocations.  In that case --remove-relocataions=* is
useful to remove all the non-dynamic relocations.

	PR binutils/23611
	* objcopy.c (handle_remove_section_option): Consider .rela and
	.rel sections for stripping directly as well as attached to the
	associated section they relocate.
	* doc/binutils.texi (remove-relocations): Specify that this
	option removes non-dynamic relocation sections.
	* testsuite/binutils-all/objcopy.exp
	(objcopy_remove_relocations_from_executable): New test.

1 files changed, 8 insertions, 5 deletions

diff --git a/binutils/doc/binutils.texi b/binutils/doc/binutils.texi
index e40ccb0..76cbed0 100644
--- a/binutils/doc/binutils.texi
+++ b/binutils/doc/binutils.texi
@@ -1321,17 +1321,20 @@ will remove all sections matching the pattern '.text.*', but will not
 remove the section '.text.foo'.
 
 @item --remove-relocations=@var{sectionpattern}
-Remove relocations from the output file for any section matching
-@var{sectionpattern}.  This option may be given more than once.  Note
-that using this option inappropriately may make the output file
-unusable.  Wildcard characters are accepted in @var{sectionpattern}.
+Remove non-dynamic relocations from the output file for any section
+matching @var{sectionpattern}.  This option may be given more than
+once.  Note that using this option inappropriately may make the output
+file unusable, and attempting to remove a dynamic relocation section
+such as @samp{.rela.plt} from an executable or shared library with
+@option{--remove-relocations=.plt} will not work.  Wildcard characters
+are accepted in @var{sectionpattern}.
 For example:
 
 @smallexample
   --remove-relocations=.text.*
 @end smallexample
 
-will remove the relocations for all sections matching the patter
+will remove the relocations for all sections matching the pattern
 '.text.*'.
 
 If the first character of @var{sectionpattern} is the exclamation