Add support to the RX toolchain to restrict the use of string instructions.

bfd	* elf32-rx.c (describe_flags): Report the settings of the string
	insn using bits.
	(rx_elf_merge_private_bfd_data): Handle merging of the string insn
	using bits.

bin	* readelf.c (get_machine_flags): Report the setting of the string
	insn using bits.

gas	* config/tc-rx.c (enum options): Add OPTION_DISALLOW_STRING_INSNS.
	(md_longopts): Add -mno-allow-string-insns.
	(md_parse_option): Handle -mno-allow-string-insns.
	(md_show_usage): Mention -mno-allow-string-insns.
	(rx_note_string_insn_use): New function.  Produces an error
	message if a string insn is used when it is not allowed.
	* config/rx-parse.y (SCMPU): Call rx_note_string_insn_use.
	(SMOVU, SMOVB, SMOVF, SUNTIL, SWHILE, RMPA): Likewise.
	* config/rx-defs.h (rx_note_string_insn_use): Prototype.
	* doc/c-rx.texi: Document -mno-allow-string-insns.

elf	* rx.h (E_FLAG_RX_SINSNS_SET): New bit in e_flags field.
	(E_FLAG_RX_SINSNS_YES): Likewise.
	(E_FLAG_RX_SINSNS_MASK): New define.

1 files changed, 15 insertions, 0 deletions

diff --git a/gas/doc/c-rx.texi b/gas/doc/c-rx.texi
index 0eddb08..abf15cd 100644
--- a/gas/doc/c-rx.texi
+++ b/gas/doc/c-rx.texi
@@ -112,6 +112,21 @@ This option tells the assembler the target CPU type.  Currently the
 cpu names.  Attempting to assemble an instruction not supported by the
 indicated cpu type will result in an error message being generated.
 
+@cindex @samp{-mno-allow-string-insns}
+@item -mno-allow-string-insns
+This option tells the assembler to mark the object file that it is
+building as one that does not use the string instructions
+@code{SMOVF}, @code{SCMPU}, @code {SMOVB}, @code{SMOVU}, @code{SUNTIL} 
+@code {SWHILE} or the @code {RMPA} instruction.  In addition the mark
+tells the linker to complain if an attempt is made to link the binary
+with another one that does use any of these instructions.
+
+Note - the inverse of this option, @code{-mallow-string-insns}, is
+not needed.  The assembler automatically detects the use of the
+the instructions in the source code and labels the resulting
+object file appropriately.  If no string instructions are detected
+then the object file is labelled as being one that can be linked with
+either string-using or string-banned object files.
 @end table
 
 @node RX-Modifiers