[Bug gas/23412] New: .intel_syntax noprefix vs -msyntax=intel -mnaked-reg segment override inconsistency

[jesse at eclypsium dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=23412

            Bug ID: 23412
           Summary: .intel_syntax noprefix vs -msyntax=intel -mnaked-reg
                    segment override inconsistency
           Product: binutils
           Version: 2.30
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: gas
          Assignee: unassigned at sourceware dot org
          Reporter: jesse at eclypsium dot com
  Target Milestone: ---

When using -msyntax=intel, as incorrectly parses instructions using segment
overrides.

# objdump -D -b binary -m i386 -M x86-64 -M intel test.bin
test.bin:     file format binary

Disassembly of section .data:

00000000 <.data>:
   0:   2e 48 8b 04 25 44 33    mov    rax,QWORD PTR cs:0x11223344
   7:   22 11

If I try to assemble this instruction using -msyntax=intel -mnaked-reg command
line arguments, as parses this instruction incorrectly and I can't find a
variation that it will accept.

# cat test-cmd-args.s 
        mov rax, QWORD PTR cs:0x11223344
        mov rax, cs:0x11223344
        mov rax, cs:[0x11223344]
        mov rax, [cs:0x11223344]

# as -msyntax=intel -mnaked-reg test-cmd-args.s
test-cmd-args.s: Assembler messages:
test-cmd-args.s:1: Error: invalid use of register
test-cmd-args.s:2: Error: junk `:0x11223344' after expression
test-cmd-args.s:3: Error: junk `:[0x11223344]' after expression
test-cmd-args.s:4: Error: bad expression
test-cmd-args.s:4: Error: junk `cs:0x11223344]' after expression

However, if I use ".intel_syntax noprefix" in the source file, all variations
are assembled correctly.

# cat test-inline.s 
        .intel_syntax noprefix
        mov rax, QWORD PTR cs:0x11223344
        mov rax, cs:0x11223344
        mov rax, cs:[0x11223344]
        mov rax, [cs:0x11223344]

# as -msyntax=intel -mnaked-reg test-inline.s

# objdump -d a.out

a.out:     file format elf64-x86-64

Disassembly of section .text:

0000000000000000 <.text>:
   0:   2e 48 8b 04 25 44 33    mov    %cs:0x11223344,%rax
   7:   22 11 
   9:   2e 48 8b 04 25 44 33    mov    %cs:0x11223344,%rax
  10:   22 11 
  12:   2e 48 8b 04 25 44 33    mov    %cs:0x11223344,%rax
  19:   22 11 
  1b:   2e 48 8b 04 25 44 33    mov    %cs:0x11223344,%rax
  22:   22 11 

# as --version
GNU assembler (GNU Binutils for Debian) 2.30
Copyright (C) 2018 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or later.
This program has absolutely no warranty.
This assembler was configured for a target of `x86_64-linux-gnu'.

There does not appear to be a way to get as to correctly assemble these
instructions without including ".intel_synax noprefix" in the source file.

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