libopcodes: extend the styling within the i386 disassembler

The i386 disassembler is pretty complex.  Most disassembly is done
indirectly; operands are built into buffers within a struct instr_info
instance, before finally being printed later in the disassembly
process.

Sometimes the operand buffers are built in a different order to the
order in which they will eventually be printed.

Each operand can contain multiple components, e.g. multiple registers,
immediates, other textual elements (commas, brackets, etc).

When looking for how to apply styling I guess the ideal solution would
be to move away from the operands being a single string that is built
up, and instead have each operand be a list of "parts", where each
part is some text and a style.  Then, when we eventually print the
operand we would loop over the parts and print each part with the
correct style.

But it feels like a huge amount of work to move from where we are
now to that potentially ideal solution.  Plus, the above solution
would be pretty complex.

So, instead I propose a .... different solution here, one that works
with the existing infrastructure.

As each operand is built up, piece be piece, we pass through style
information.  This style information is then encoded into the operand
buffer (see below for details).  After this the code can continue to
operate as it does right now in order to manage the set of operand
buffers.

Then, as each operand is printed we can split the operand buffer into
chunks at the style marker boundaries, with each chunk being printed
with the correct style.

For encoding the style information I use a single character, currently
\002, followed by the style encoded as a single hex digit, followed
again by the \002 character.

This of course relies on there not being more than 16 styles, but that
is currently true, and hopefully will remain true for the foreseeable
future.

The other major concern that has arisen around this work is whether
the escape character could ever be encountered in output naturally
generated by the disassembler.  If this did happen then the escape
characters would be stripped from the output, and the wrong styling
would be applied.

However, I don't believe that this is currently a problem.
Disassembler content comes from a number of sources.  First there's
content that copied directly from the i386-dis.c file, this is things
like register names, and other syntax elements (brackets, commas,
etc).  We can easily check that the i386-dis.c file doesn't contain
our special character.

The next source of content are immediate operands.  The text for these
operands is generated by calls into libc.  By selecting a
non-printable character we can be confident that this is not something
that libc will generate as part of an immediate representation.

The other output that appears to be from the disassembler is operands
that contain addresses and (possibly) symbol names.  It is quite
possible that a symbol name might contain any special character we
could imagine, so is this a problem?

I don't think it is, we don't actually print address and symbol
operands through the disassembler, instead, the disassembler calls
back to the user (objdump, gdb, etc) to print the address and symbol
on its behalf.  This content is printed directly to the output stream,
it does not pass through the i386 disassembler output buffers.  As a
result, we never check this particular output for styling escape
characters.

In some (not very scientific) benchmarking on my machine,
disassembling a reasonably large (142M) shared library, I'm not seeing
any significant slow down in disassembler speed with this change.

Most instructions are now being fully syntax highlighted when I
disassemble using the --disassembler-color=extended-color option.  I'm
sure that there are probably still a few corner cases that need fixing
up, but we can come back to them later I think.

When disassembler syntax highlighting is not being used, then there
should be no user visible changes after this commit.

1 files changed, 286 insertions, 137 deletions

diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index 7b99969b23..f7b5e3b731 100644
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -47,6 +47,8 @@ static void dofloat (instr_info *, int);
 static void OP_ST (instr_info *, int, int);
 static void OP_STi (instr_info *, int, int);
 static int putop (instr_info *, const char *, int);
+static void oappend_with_style (instr_info *, const char *,
+				enum disassembler_style);
 static void oappend (instr_info *, const char *);
 static void append_seg (instr_info *);
 static void OP_indirE (instr_info *, int, int);
@@ -116,6 +118,10 @@ static void FXSAVE_Fixup (instr_info *, int, int);
 static void MOVSXD_Fixup (instr_info *, int, int);
 static void DistinctDest_Fixup (instr_info *, int, int);
 
+/* This character is used to encode style information within the output
+   buffers.  See oappend_insert_style for more details.  */
+#define STYLE_MARKER_CHAR '\002'
+
 struct dis_private {
   /* Points to first byte not fetched.  */
   bfd_byte *max_fetched;
@@ -247,7 +253,6 @@ struct instr_info
   char scale_char;
 
   enum x86_64_isa isa64;
-
 };
 
 /* Mark parts used in the REX prefix.  When we are testing for
@@ -9298,12 +9303,121 @@ get_sib (instr_info *ins, int sizeflag)
     ins->has_sib = false;
 }
 
-/* Like oappend (below), but S is a string starting with '%'.
-   In Intel syntax, the '%' is elided.  */
+/* Like oappend (below), but S is a string starting with '%' or '$'.  In
+   Intel syntax, the '%' or '$' is elided.  STYLE is used when displaying
+   this part of the output in the disassembler.
+
+   This function should not be used directly from the general disassembler
+   code, instead the helpers oappend_register and oappend_immediate should
+   be called as appropriate.  */
+
+static void
+oappend_maybe_intel_with_style (instr_info *ins, const char *s,
+				enum disassembler_style style)
+{
+  oappend_with_style (ins, s + ins->intel_syntax, style);
+}
+
+/* Like oappend_maybe_intel_with_style above, but called when S is the
+   name of a register.  */
+
 static void
-oappend_maybe_intel (instr_info *ins, const char *s)
+oappend_register (instr_info *ins, const char *s)
+{
+  oappend_maybe_intel_with_style (ins, s, dis_style_register);
+}
+
+/* Like oappend_maybe_intel_with_style above, but called when S represents
+   an immediate.  */
+
+static void
+oappend_immediate (instr_info *ins, const char *s)
+{
+  oappend_maybe_intel_with_style (ins, s, dis_style_immediate);
+}
+
+/* Wrap around a call to INS->info->fprintf_styled_func, printing FMT.
+   STYLE is the default style to use in the fprintf_styled_func calls,
+   however, FMT might include embedded style markers (see oappend_style),
+   these embedded markers are not printed, but instead change the style
+   used in the next fprintf_styled_func call.
+
+   Return non-zero to indicate the print call was a success.  */
+
+static int ATTRIBUTE_PRINTF_3
+i386_dis_printf (instr_info *ins, enum disassembler_style style,
+		 const char *fmt, ...)
 {
-  oappend (ins, s + ins->intel_syntax);
+  va_list ap;
+  enum disassembler_style curr_style = style;
+  char *start, *curr;
+  char staging_area[100];
+  int res;
+
+  va_start (ap, fmt);
+  res = vsnprintf (staging_area, sizeof (staging_area), fmt, ap);
+  va_end (ap);
+
+  if (res < 0)
+    return res;
+
+  if ((size_t) res >= sizeof (staging_area))
+    abort ();
+
+  start = curr = staging_area;
+
+  do
+    {
+      if (*curr == '\0'
+	  || (*curr == STYLE_MARKER_CHAR
+	      && ISXDIGIT (*(curr + 1))
+	      && *(curr + 2) == STYLE_MARKER_CHAR))
+	{
+	  /* Output content between our START position and CURR.  */
+	  int len = curr - start;
+	  int n = (*ins->info->fprintf_styled_func) (ins->info->stream,
+						     curr_style,
+						     "%.*s", len, start);
+	  if (n < 0)
+	    {
+	      res = n;
+	      break;
+	    }
+
+	  if (*curr == '\0')
+	    break;
+
+	  /* Skip over the initial STYLE_MARKER_CHAR.  */
+	  ++curr;
+
+	  /* Update the CURR_STYLE.  As there are less than 16 styles, it
+	     is possible, that if the input is corrupted in some way, that
+	     we might set CURR_STYLE to an invalid value.  Don't worry
+	     though, we check for this situation.  */
+	  if (*curr >= '0' && *curr <= '9')
+	    curr_style = (enum disassembler_style) (*curr - '0');
+	  else if (*curr >= 'a' && *curr <= 'f')
+	    curr_style = (enum disassembler_style) (*curr - 'a' + 10);
+	  else
+	    curr_style = dis_style_text;
+
+	  /* Check for an invalid style having been selected.  This should
+	     never happen, but it doesn't hurt to be a little paranoid.  */
+	  if (curr_style > dis_style_comment_start)
+	    curr_style = dis_style_text;
+
+	  /* Skip the hex character, and the closing STYLE_MARKER_CHAR.  */
+	  curr += 2;
+
+	  /* Reset the START to after the style marker.  */
+	  start = curr;
+	}
+      else
+	++curr;
+    }
+  while (true);
+
+  return res;
 }
 
 static int
@@ -9404,8 +9518,7 @@ print_insn (bfd_vma pc, instr_info *ins)
 
   if (ins->address_mode == mode_64bit && sizeof (bfd_vma) < 8)
     {
-      (*ins->info->fprintf_styled_func) (ins->info->stream, dis_style_text,
-					 _("64-bit address is disabled"));
+      i386_dis_printf (ins, dis_style_text, _("64-bit address is disabled"));
       return -1;
     }
 
@@ -9454,16 +9567,14 @@ print_insn (bfd_vma pc, instr_info *ins)
 	{
 	  name = prefix_name (ins, priv.the_buffer[0], priv.orig_sizeflag);
 	  if (name != NULL)
-	    (*ins->info->fprintf_styled_func)
-	      (ins->info->stream, dis_style_mnemonic, "%s", name);
+	    i386_dis_printf (ins, dis_style_mnemonic, "%s", name);
 	  else
 	    {
 	      /* Just print the first byte as a .byte instruction.  */
-	      (*ins->info->fprintf_styled_func)
-		(ins->info->stream, dis_style_assembler_directive, ".byte ");
-	      (*ins->info->fprintf_styled_func)
-		(ins->info->stream, dis_style_immediate, "0x%x",
-		 (unsigned int) priv.the_buffer[0]);
+	      i386_dis_printf (ins, dis_style_assembler_directive,
+			       ".byte ");
+	      i386_dis_printf (ins, dis_style_immediate, "0x%x",
+			       (unsigned int) priv.the_buffer[0]);
 	    }
 
 	  return 1;
@@ -9481,10 +9592,9 @@ print_insn (bfd_vma pc, instr_info *ins)
       for (i = 0;
 	   i < (int) ARRAY_SIZE (ins->all_prefixes) && ins->all_prefixes[i];
 	   i++)
-	(*ins->info->fprintf_styled_func)
-	  (ins->info->stream, dis_style_mnemonic, "%s%s",
-	   (i == 0 ? "" : " "), prefix_name (ins, ins->all_prefixes[i],
-					     sizeflag));
+	i386_dis_printf (ins, dis_style_mnemonic, "%s%s",
+			 (i == 0 ? "" : " "),
+			 prefix_name (ins, ins->all_prefixes[i], sizeflag));
       return i;
     }
 
@@ -9499,11 +9609,9 @@ print_insn (bfd_vma pc, instr_info *ins)
       /* Handle ins->prefixes before fwait.  */
       for (i = 0; i < ins->fwait_prefix && ins->all_prefixes[i];
 	   i++)
-	(*ins->info->fprintf_styled_func)
-	  (ins->info->stream, dis_style_mnemonic, "%s ",
-	   prefix_name (ins, ins->all_prefixes[i], sizeflag));
-      (*ins->info->fprintf_styled_func)
-	(ins->info->stream, dis_style_mnemonic, "fwait");
+	i386_dis_printf (ins, dis_style_mnemonic, "%s ",
+			 prefix_name (ins, ins->all_prefixes[i], sizeflag));
+      i386_dis_printf (ins, dis_style_mnemonic, "fwait");
       return i + 1;
     }
 
@@ -9572,10 +9680,10 @@ print_insn (bfd_vma pc, instr_info *ins)
 		  /* Don't print {%k0}.  */
 		  if (ins->vex.mask_register_specifier)
 		    {
+		      const char *reg_name
+			= att_names_mask[ins->vex.mask_register_specifier];
 		      oappend (ins, "{");
-		      oappend_maybe_intel (ins,
-					   att_names_mask
-					   [ins->vex.mask_register_specifier]);
+		      oappend_register (ins, reg_name);
 		      oappend (ins, "}");
 		    }
 		  if (ins->vex.zeroing)
@@ -9652,16 +9760,14 @@ print_insn (bfd_vma pc, instr_info *ins)
      are all 0s in inverted form.  */
   if (ins->need_vex && ins->vex.register_specifier != 0)
     {
-      (*ins->info->fprintf_styled_func) (ins->info->stream, dis_style_text,
-					 "(bad)");
+      i386_dis_printf (ins, dis_style_text, "(bad)");
       return ins->end_codep - priv.the_buffer;
     }
 
   /* If EVEX.z is set, there must be an actual mask register in use.  */
   if (ins->vex.zeroing && ins->vex.mask_register_specifier == 0)
     {
-      (*ins->info->fprintf_styled_func) (ins->info->stream, dis_style_text,
-					 "(bad)");
+      i386_dis_printf (ins, dis_style_text, "(bad)");
       return ins->end_codep - priv.the_buffer;
     }
 
@@ -9672,8 +9778,7 @@ print_insn (bfd_vma pc, instr_info *ins)
 	 the encoding invalid.  Most other PREFIX_OPCODE rules still apply.  */
       if (ins->need_vex ? !ins->vex.prefix : !(ins->prefixes & PREFIX_DATA))
 	{
-	  (*ins->info->fprintf_styled_func) (ins->info->stream,
-					     dis_style_text, "(bad)");
+	  i386_dis_printf (ins, dis_style_text, "(bad)");
 	  return ins->end_codep - priv.the_buffer;
 	}
       ins->used_prefixes |= PREFIX_DATA;
@@ -9700,8 +9805,7 @@ print_insn (bfd_vma pc, instr_info *ins)
 	  || (ins->vex.evex && dp->prefix_requirement != PREFIX_DATA
 	      && !ins->vex.w != !(ins->used_prefixes & PREFIX_DATA)))
 	{
-	  (*ins->info->fprintf_styled_func) (ins->info->stream,
-					     dis_style_text, "(bad)");
+	  i386_dis_printf (ins, dis_style_text, "(bad)");
 	  return ins->end_codep - priv.the_buffer;
 	}
       break;
@@ -9751,15 +9855,13 @@ print_insn (bfd_vma pc, instr_info *ins)
 	if (name == NULL)
 	  abort ();
 	prefix_length += strlen (name) + 1;
-	(*ins->info->fprintf_styled_func)
-	  (ins->info->stream, dis_style_mnemonic, "%s ", name);
+	i386_dis_printf (ins, dis_style_mnemonic, "%s ", name);
       }
 
   /* Check maximum code length.  */
   if ((ins->codep - ins->start_codep) > MAX_CODE_LENGTH)
     {
-      (*ins->info->fprintf_styled_func)
-	(ins->info->stream, dis_style_text, "(bad)");
+      i386_dis_printf (ins, dis_style_text, "(bad)");
       return MAX_CODE_LENGTH;
     }
 
@@ -9783,8 +9885,7 @@ print_insn (bfd_vma pc, instr_info *ins)
     i = 0;
 
   /* Print the instruction mnemonic along with any trailing whitespace.  */
-  (*ins->info->fprintf_styled_func)
-    (ins->info->stream, dis_style_mnemonic, "%s%*s", ins->obuf, i, "");
+  i386_dis_printf (ins, dis_style_mnemonic, "%s%*s", ins->obuf, i, "");
 
   /* The enter and bound instructions are printed with operands in the same
      order as the intel book; everything else is printed in reverse order.  */
@@ -9839,8 +9940,7 @@ print_insn (bfd_vma pc, instr_info *ins)
 	    break;
 	  }
 	if (needcomma)
-	  (*ins->info->fprintf_styled_func) (ins->info->stream,
-					     dis_style_text, ",");
+	  i386_dis_printf (ins, dis_style_text, ",");
 	if (ins->op_index[i] != -1 && !ins->op_riprel[i])
 	  {
 	    bfd_vma target = (bfd_vma) ins->op_address[ins->op_index[i]];
@@ -9856,18 +9956,14 @@ print_insn (bfd_vma pc, instr_info *ins)
 	    (*ins->info->print_address_func) (target, ins->info);
 	  }
 	else
-	  (*ins->info->fprintf_styled_func) (ins->info->stream,
-					     dis_style_text, "%s",
-					     op_txt[i]);
+	  i386_dis_printf (ins, dis_style_text, "%s", op_txt[i]);
 	needcomma = 1;
       }
 
   for (i = 0; i < MAX_OPERANDS; i++)
     if (ins->op_index[i] != -1 && ins->op_riprel[i])
       {
-	(*ins->info->fprintf_styled_func) (ins->info->stream,
-					   dis_style_comment_start,
-					   "        # ");
+	i386_dis_printf (ins, dis_style_comment_start, "        # ");
 	(*ins->info->print_address_func) ((bfd_vma)
 			(ins->start_pc + (ins->codep - ins->start_codep)
 			 + ins->op_address[ins->op_index[i]]), ins->info);
@@ -10252,7 +10348,7 @@ static void
 OP_ST (instr_info *ins, int bytemode ATTRIBUTE_UNUSED,
        int sizeflag ATTRIBUTE_UNUSED)
 {
-  oappend_maybe_intel (ins, "%st");
+  oappend_register (ins, "%st");
 }
 
 static void
@@ -10260,7 +10356,7 @@ OP_STi (instr_info *ins, int bytemode ATTRIBUTE_UNUSED,
 	int sizeflag ATTRIBUTE_UNUSED)
 {
   sprintf (ins->scratchbuf, "%%st(%d)", ins->modrm.rm);
-  oappend_maybe_intel (ins, ins->scratchbuf);
+  oappend_register (ins, ins->scratchbuf);
 }
 
 /* Capital letters in template are macros.  */
@@ -10807,12 +10903,73 @@ putop (instr_info *ins, const char *in_template, int sizeflag)
   return 0;
 }
 
+/* Add a style marker to *INS->obufp that encodes STYLE.  This assumes that
+   the buffer pointed to by INS->obufp has space.  A style marker is made
+   from the STYLE_MARKER_CHAR followed by STYLE converted to a single hex
+   digit, followed by another STYLE_MARKER_CHAR.  This function assumes
+   that the number of styles is not greater than 16.  */
+
 static void
-oappend (instr_info *ins, const char *s)
+oappend_insert_style (instr_info *ins, enum disassembler_style style)
 {
+  unsigned num = (unsigned) style;
+
+  /* We currently assume that STYLE can be encoded as a single hex
+     character.  If more styles are added then this might start to fail,
+     and we'll need to expand this code.  */
+  if (num > 0xf)
+    abort ();
+
+  *ins->obufp++ = STYLE_MARKER_CHAR;
+  *ins->obufp++ = (num < 10 ? ('0' + num)
+		   : ((num < 16) ? ('a' + (num - 10)) : '0'));
+  *ins->obufp++ = STYLE_MARKER_CHAR;
+
+  /* This final null character is not strictly necessary, after inserting a
+     style marker we should always be inserting some additional content.
+     However, having the buffer null terminated doesn't cost much, and make
+     it easier to debug what's going on.  Also, if we do ever forget to add
+     any additional content after this style marker, then the buffer will
+     still be well formed.  */
+  *ins->obufp = '\0';
+}
+
+static void
+oappend_with_style (instr_info *ins, const char *s,
+		    enum disassembler_style style)
+{
+  oappend_insert_style (ins, style);
   ins->obufp = stpcpy (ins->obufp, s);
 }
 
+/* Like oappend_with_style but always with text style.  */
+
+static void
+oappend (instr_info *ins, const char *s)
+{
+  oappend_with_style (ins, s, dis_style_text);
+}
+
+/* Add a single character C to the buffer pointer to by INS->obufp, marking
+   the style for the character as STYLE.  */
+
+static void
+oappend_char_with_style (instr_info *ins, const char c,
+			 enum disassembler_style style)
+{
+  oappend_insert_style (ins, style);
+  *ins->obufp++ = c;
+  *ins->obufp = '\0';
+}
+
+/* Like oappend_char_with_style, but always uses dis_style_text.  */
+
+static void
+oappend_char (instr_info *ins, const char c)
+{
+  oappend_char_with_style (ins, c, dis_style_text);
+}
+
 static void
 append_seg (instr_info *ins)
 {
@@ -10824,26 +10981,27 @@ append_seg (instr_info *ins)
   switch (ins->active_seg_prefix)
     {
     case PREFIX_CS:
-      oappend_maybe_intel (ins, "%cs:");
+      oappend_register (ins, "%cs");
       break;
     case PREFIX_DS:
-      oappend_maybe_intel (ins, "%ds:");
+      oappend_register (ins, "%ds");
       break;
     case PREFIX_SS:
-      oappend_maybe_intel (ins, "%ss:");
+      oappend_register (ins, "%ss");
       break;
     case PREFIX_ES:
-      oappend_maybe_intel (ins, "%es:");
+      oappend_register (ins, "%es");
       break;
     case PREFIX_FS:
-      oappend_maybe_intel (ins, "%fs:");
+      oappend_register (ins, "%fs");
       break;
     case PREFIX_GS:
-      oappend_maybe_intel (ins, "%gs:");
+      oappend_register (ins, "%gs");
       break;
     default:
       break;
     }
+  oappend_char (ins, ':');
 }
 
 static void
@@ -11331,7 +11489,7 @@ print_register (instr_info *ins, unsigned int reg, unsigned int rexmask,
       oappend (ins, INTERNAL_DISASSEMBLER_ERROR);
       return;
     }
-  oappend_maybe_intel (ins, names[reg]);
+  oappend_register (ins, names[reg]);
 }
 
 static void
@@ -11595,11 +11753,15 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
 	      print_displacement (ins, ins->scratchbuf, disp);
 	    else
 	      print_operand_value (ins, ins->scratchbuf, 1, disp);
-	    oappend (ins, ins->scratchbuf);
+	    oappend_with_style (ins, ins->scratchbuf,
+				dis_style_address_offset);
 	    if (riprel)
 	      {
 		set_op (ins, disp, true);
-		oappend (ins, !addr32flag ? "(%rip)" : "(%eip)");
+		oappend_char (ins, '(');
+		oappend_with_style (ins, !addr32flag ? "%rip" : "%eip",
+				    dis_style_register);
+		oappend_char (ins, ')');
 	      }
 	  }
 
@@ -11613,17 +11775,18 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
 
       if (havedisp || (ins->intel_syntax && riprel))
 	{
-	  *ins->obufp++ = ins->open_char;
+	  oappend_char (ins, ins->open_char);
 	  if (ins->intel_syntax && riprel)
 	    {
 	      set_op (ins, disp, true);
-	      oappend (ins, !addr32flag ? "rip" : "eip");
+	      oappend_with_style (ins, !addr32flag ? "rip" : "eip",
+				  dis_style_register);
 	    }
-	  *ins->obufp = '\0';
 	  if (havebase)
-	    oappend_maybe_intel (ins,
-				 (ins->address_mode == mode_64bit && !addr32flag
-				  ? att_names64 : att_names32)[rbase]);
+	    oappend_register
+	      (ins,
+	       (ins->address_mode == mode_64bit && !addr32flag
+		? att_names64 : att_names32)[rbase]);
 	  if (ins->has_sib)
 	    {
 	      /* ESP/RSP won't allow index.  If base isn't ESP/RSP,
@@ -11634,41 +11797,35 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
 		  || (havebase && base != ESP_REG_NUM))
 		{
 		  if (!ins->intel_syntax || havebase)
-		    {
-		      *ins->obufp++ = ins->separator_char;
-		      *ins->obufp = '\0';
-		    }
+		    oappend_char (ins, ins->separator_char);
 		  if (indexes)
 		    {
 		      if (ins->address_mode == mode_64bit || vindex < 16)
-			oappend_maybe_intel (ins, indexes[vindex]);
+			oappend_register (ins, indexes[vindex]);
 		      else
 			oappend (ins, "(bad)");
 		    }
 		  else
-		    oappend_maybe_intel (ins,
-					 ins->address_mode == mode_64bit
-					 && !addr32flag ? att_index64
-							: att_index32);
+		    oappend_register (ins,
+				      ins->address_mode == mode_64bit
+				      && !addr32flag
+				      ? att_index64
+				      : att_index32);
 
-		  *ins->obufp++ = ins->scale_char;
-		  *ins->obufp = '\0';
+		  oappend_char (ins, ins->scale_char);
 		  sprintf (ins->scratchbuf, "%d", 1 << scale);
-		  oappend (ins, ins->scratchbuf);
+		  oappend_with_style (ins, ins->scratchbuf,
+				      dis_style_immediate);
 		}
 	    }
 	  if (ins->intel_syntax
 	      && (disp || ins->modrm.mod != 0 || base == 5))
 	    {
 	      if (!havedisp || (bfd_signed_vma) disp >= 0)
-		{
-		  *ins->obufp++ = '+';
-		  *ins->obufp = '\0';
-		}
+		  oappend_char (ins, '+');
 	      else if (ins->modrm.mod != 1 && disp != -disp)
 		{
-		  *ins->obufp++ = '-';
-		  *ins->obufp = '\0';
+		  oappend_char (ins, '-');
 		  disp = -disp;
 		}
 
@@ -11679,8 +11836,7 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
 	      oappend (ins, ins->scratchbuf);
 	    }
 
-	  *ins->obufp++ = ins->close_char;
-	  *ins->obufp = '\0';
+	  oappend_char (ins, ins->close_char);
 
 	  if (check_gather)
 	    {
@@ -11701,7 +11857,7 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
 	    {
 	      if (!ins->active_seg_prefix)
 		{
-		  oappend_maybe_intel (ins, att_names_seg[ds_reg - es_reg]);
+		  oappend_register (ins, att_names_seg[ds_reg - es_reg]);
 		  oappend (ins, ":");
 		}
 	      print_operand_value (ins, ins->scratchbuf, 1, disp);
@@ -11757,23 +11913,17 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
 
       if (ins->modrm.mod != 0 || ins->modrm.rm != 6)
 	{
-	  *ins->obufp++ = ins->open_char;
-	  *ins->obufp = '\0';
-	  oappend (ins,
-		   (ins->intel_syntax ? intel_index16
-				      : att_index16)[ins->modrm.rm]);
+	  oappend_char (ins, ins->open_char);
+	  oappend (ins, (ins->intel_syntax ? intel_index16
+			 : att_index16)[ins->modrm.rm]);
 	  if (ins->intel_syntax
 	      && (disp || ins->modrm.mod != 0 || ins->modrm.rm == 6))
 	    {
 	      if ((bfd_signed_vma) disp >= 0)
-		{
-		  *ins->obufp++ = '+';
-		  *ins->obufp = '\0';
-		}
+		oappend_char (ins, '+');
 	      else if (ins->modrm.mod != 1)
 		{
-		  *ins->obufp++ = '-';
-		  *ins->obufp = '\0';
+		  oappend_char (ins, '-');
 		  disp = -disp;
 		}
 
@@ -11781,14 +11931,13 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
 	      oappend (ins, ins->scratchbuf);
 	    }
 
-	  *ins->obufp++ = ins->close_char;
-	  *ins->obufp = '\0';
+	  oappend_char (ins, ins->close_char);
 	}
       else if (ins->intel_syntax)
 	{
 	  if (!ins->active_seg_prefix)
 	    {
-	      oappend_maybe_intel (ins, att_names_seg[ds_reg - es_reg]);
+	      oappend_register (ins, att_names_seg[ds_reg - es_reg]);
 	      oappend (ins, ":");
 	    }
 	  print_operand_value (ins, ins->scratchbuf, 1, disp & 0xffff);
@@ -11999,7 +12148,7 @@ OP_REG (instr_info *ins, int code, int sizeflag)
     {
     case es_reg: case ss_reg: case cs_reg:
     case ds_reg: case fs_reg: case gs_reg:
-      oappend_maybe_intel (ins, att_names_seg[code - es_reg]);
+      oappend_register (ins, att_names_seg[code - es_reg]);
       return;
     }
 
@@ -12052,7 +12201,7 @@ OP_REG (instr_info *ins, int code, int sizeflag)
       oappend (ins, INTERNAL_DISASSEMBLER_ERROR);
       return;
     }
-  oappend_maybe_intel (ins, s);
+  oappend_register (ins, s);
 }
 
 static void
@@ -12093,7 +12242,7 @@ OP_IMREG (instr_info *ins, int code, int sizeflag)
       oappend (ins, INTERNAL_DISASSEMBLER_ERROR);
       return;
     }
-  oappend_maybe_intel (ins, s);
+  oappend_register (ins, s);
 }
 
 static void
@@ -12148,7 +12297,7 @@ OP_I (instr_info *ins, int bytemode, int sizeflag)
   op &= mask;
   ins->scratchbuf[0] = '$';
   print_operand_value (ins, ins->scratchbuf + 1, 1, op);
-  oappend_maybe_intel (ins, ins->scratchbuf);
+  oappend_immediate (ins, ins->scratchbuf);
   ins->scratchbuf[0] = '\0';
 }
 
@@ -12166,7 +12315,7 @@ OP_I64 (instr_info *ins, int bytemode, int sizeflag)
 
   ins->scratchbuf[0] = '$';
   print_operand_value (ins, ins->scratchbuf + 1, 1, get64 (ins));
-  oappend_maybe_intel (ins, ins->scratchbuf);
+  oappend_immediate (ins, ins->scratchbuf);
   ins->scratchbuf[0] = '\0';
 }
 
@@ -12220,7 +12369,7 @@ OP_sI (instr_info *ins, int bytemode, int sizeflag)
 
   ins->scratchbuf[0] = '$';
   print_operand_value (ins, ins->scratchbuf + 1, 1, op);
-  oappend_maybe_intel (ins, ins->scratchbuf);
+  oappend_immediate (ins, ins->scratchbuf);
 }
 
 static void
@@ -12278,7 +12427,7 @@ static void
 OP_SEG (instr_info *ins, int bytemode, int sizeflag)
 {
   if (bytemode == w_mode)
-    oappend_maybe_intel (ins, att_names_seg[ins->modrm.reg]);
+    oappend_register (ins, att_names_seg[ins->modrm.reg]);
   else
     OP_E (ins, ins->modrm.mod == 3 ? bytemode : w_mode, sizeflag);
 }
@@ -12324,12 +12473,12 @@ OP_OFF (instr_info *ins, int bytemode, int sizeflag)
     {
       if (!ins->active_seg_prefix)
 	{
-	  oappend_maybe_intel (ins, att_names_seg[ds_reg - es_reg]);
+	  oappend_register (ins, att_names_seg[ds_reg - es_reg]);
 	  oappend (ins, ":");
 	}
     }
   print_operand_value (ins, ins->scratchbuf, 1, off);
-  oappend (ins, ins->scratchbuf);
+  oappend_with_style (ins, ins->scratchbuf, dis_style_address_offset);
 }
 
 static void
@@ -12354,12 +12503,12 @@ OP_OFF64 (instr_info *ins, int bytemode, int sizeflag)
     {
       if (!ins->active_seg_prefix)
 	{
-	  oappend_maybe_intel (ins, att_names_seg[ds_reg - es_reg]);
+	  oappend_register (ins, att_names_seg[ds_reg - es_reg]);
 	  oappend (ins, ":");
 	}
     }
   print_operand_value (ins, ins->scratchbuf, 1, off);
-  oappend (ins, ins->scratchbuf);
+  oappend_with_style (ins, ins->scratchbuf, dis_style_address_offset);
 }
 
 static void
@@ -12380,9 +12529,8 @@ ptr_reg (instr_info *ins, int code, int sizeflag)
     s = att_names32[code - eAX_reg];
   else
     s = att_names16[code - eAX_reg];
-  oappend_maybe_intel (ins, s);
-  *ins->obufp++ = ins->close_char;
-  *ins->obufp = 0;
+  oappend_register (ins, s);
+  oappend_char (ins, ins->close_char);
 }
 
 static void
@@ -12405,7 +12553,8 @@ OP_ESreg (instr_info *ins, int code, int sizeflag)
 	  intel_operand_size (ins, b_mode, sizeflag);
 	}
     }
-  oappend_maybe_intel (ins, "%es:");
+  oappend_register (ins, "%es");
+  oappend_char (ins, ':');
   ptr_reg (ins, code, sizeflag);
 }
 
@@ -12455,7 +12604,7 @@ OP_C (instr_info *ins, int dummy ATTRIBUTE_UNUSED,
   else
     add = 0;
   sprintf (ins->scratchbuf, "%%cr%d", ins->modrm.reg + add);
-  oappend_maybe_intel (ins, ins->scratchbuf);
+  oappend_register (ins, ins->scratchbuf);
 }
 
 static void
@@ -12480,7 +12629,7 @@ OP_T (instr_info *ins, int dummy ATTRIBUTE_UNUSED,
       int sizeflag ATTRIBUTE_UNUSED)
 {
   sprintf (ins->scratchbuf, "%%tr%d", ins->modrm.reg);
-  oappend_maybe_intel (ins, ins->scratchbuf);
+  oappend_register (ins, ins->scratchbuf);
 }
 
 static void
@@ -12500,7 +12649,7 @@ OP_MMX (instr_info *ins, int bytemode ATTRIBUTE_UNUSED,
     }
   else
     names = att_names_mm;
-  oappend_maybe_intel (ins, names[reg]);
+  oappend_register (ins, names[reg]);
 }
 
 static void
@@ -12575,7 +12724,7 @@ print_vector_reg (instr_info *ins, unsigned int reg, int bytemode)
     }
   else
     names = att_names_xmm;
-  oappend_maybe_intel (ins, names[reg]);
+  oappend_register (ins, names[reg]);
 }
 
 static void
@@ -12635,7 +12784,7 @@ OP_EM (instr_info *ins, int bytemode, int sizeflag)
     }
   else
     names = att_names_mm;
-  oappend_maybe_intel (ins, names[reg]);
+  oappend_register (ins, names[reg]);
 }
 
 /* cvt* are the only instructions in sse2 which have
@@ -12661,7 +12810,7 @@ OP_EMC (instr_info *ins, int bytemode, int sizeflag)
   MODRM_CHECK;
   ins->codep++;
   ins->used_prefixes |= (ins->prefixes & PREFIX_DATA);
-  oappend_maybe_intel (ins, att_names_mm[ins->modrm.rm]);
+  oappend_register (ins, att_names_mm[ins->modrm.rm]);
 }
 
 static void
@@ -12669,7 +12818,7 @@ OP_MXC (instr_info *ins, int bytemode ATTRIBUTE_UNUSED,
 	int sizeflag ATTRIBUTE_UNUSED)
 {
   ins->used_prefixes |= (ins->prefixes & PREFIX_DATA);
-  oappend_maybe_intel (ins, att_names_mm[ins->modrm.reg]);
+  oappend_register (ins, att_names_mm[ins->modrm.reg]);
 }
 
 static void
@@ -12845,7 +12994,7 @@ OP_3DNowSuffix (instr_info *ins, int bytemode ATTRIBUTE_UNUSED,
   ins->obufp = ins->mnemonicendp;
   mnemonic = Suffix3DNow[*ins->codep++ & 0xff];
   if (mnemonic)
-    oappend (ins, mnemonic);
+    ins->obufp = stpcpy (ins->obufp, mnemonic);
   else
     {
       /* Since a variable sized ins->modrm/ins->sib chunk is between the start
@@ -12934,7 +13083,7 @@ CMP_Fixup (instr_info *ins, int bytemode ATTRIBUTE_UNUSED,
       /* We have a reserved extension byte.  Output it directly.  */
       ins->scratchbuf[0] = '$';
       print_operand_value (ins, ins->scratchbuf + 1, 1, cmp_type);
-      oappend_maybe_intel (ins, ins->scratchbuf);
+      oappend_immediate (ins, ins->scratchbuf);
       ins->scratchbuf[0] = '\0';
     }
 }
@@ -12991,7 +13140,7 @@ BadOp (instr_info *ins)
 {
   /* Throw away prefixes and 1st. opcode byte.  */
   ins->codep = ins->insn_codep + 1;
-  oappend (ins, "(bad)");
+  ins->obufp = stpcpy (ins->obufp, "(bad)");
 }
 
 static void
@@ -13155,7 +13304,7 @@ XMM_Fixup (instr_info *ins, int reg, int sizeflag ATTRIBUTE_UNUSED)
 	  abort ();
 	}
     }
-  oappend_maybe_intel (ins, names[reg]);
+  oappend_register (ins, names[reg]);
 }
 
 static void
@@ -13204,7 +13353,7 @@ OP_VEX (instr_info *ins, int bytemode, int sizeflag ATTRIBUTE_UNUSED)
   switch (bytemode)
     {
     case scalar_mode:
-      oappend_maybe_intel (ins, att_names_xmm[reg]);
+      oappend_register (ins, att_names_xmm[reg]);
       return;
 
     case vex_vsib_d_w_dq_mode:
@@ -13215,9 +13364,9 @@ OP_VEX (instr_info *ins, int bytemode, int sizeflag ATTRIBUTE_UNUSED)
       if (ins->vex.length == 128
 	  || (bytemode != vex_vsib_d_w_dq_mode
 	      && !ins->vex.w))
-	oappend_maybe_intel (ins, att_names_xmm[reg]);
+	oappend_register (ins, att_names_xmm[reg]);
       else
-	oappend_maybe_intel (ins, att_names_ymm[reg]);
+	oappend_register (ins, att_names_ymm[reg]);
 
       /* All 3 XMM/YMM registers must be distinct.  */
       modrm_reg = ins->modrm.reg;
@@ -13249,7 +13398,7 @@ OP_VEX (instr_info *ins, int bytemode, int sizeflag ATTRIBUTE_UNUSED)
 	  /* This must be the 3rd operand.  */
 	  if (ins->obufp != ins->op_out[2])
 	    abort ();
-	  oappend_maybe_intel (ins, att_names_tmm[reg]);
+	  oappend_register (ins, att_names_tmm[reg]);
 	  if (reg == ins->modrm.reg || reg == ins->modrm.rm)
 	    strcpy (ins->obufp, "/(bad)");
 	}
@@ -13327,7 +13476,7 @@ OP_VEX (instr_info *ins, int bytemode, int sizeflag ATTRIBUTE_UNUSED)
       abort ();
       break;
     }
-  oappend_maybe_intel (ins, names[reg]);
+  oappend_register (ins, names[reg]);
 }
 
 static void
@@ -13370,7 +13519,7 @@ OP_REG_VexI4 (instr_info *ins, int bytemode, int sizeflag ATTRIBUTE_UNUSED)
   if (bytemode == x_mode && ins->vex.length == 256)
     names = att_names_ymm;
 
-  oappend_maybe_intel (ins, names[reg]);
+  oappend_register (ins, names[reg]);
 
   if (ins->vex.w)
     {
@@ -13387,7 +13536,7 @@ OP_VexI4 (instr_info *ins, int bytemode ATTRIBUTE_UNUSED,
 {
   ins->scratchbuf[0] = '$';
   print_operand_value (ins, ins->scratchbuf + 1, 1, ins->codep[-1] & 0xf);
-  oappend_maybe_intel (ins, ins->scratchbuf);
+  oappend_immediate (ins, ins->scratchbuf);
 }
 
 static void
@@ -13432,7 +13581,7 @@ VPCMP_Fixup (instr_info *ins, int bytemode ATTRIBUTE_UNUSED,
       /* We have a reserved extension byte.  Output it directly.  */
       ins->scratchbuf[0] = '$';
       print_operand_value (ins, ins->scratchbuf + 1, 1, cmp_type);
-      oappend_maybe_intel (ins, ins->scratchbuf);
+      oappend_immediate (ins, ins->scratchbuf);
       ins->scratchbuf[0] = '\0';
     }
 }
@@ -13484,7 +13633,7 @@ VPCOM_Fixup (instr_info *ins, int bytemode ATTRIBUTE_UNUSED,
       /* We have a reserved extension byte.  Output it directly.  */
       ins->scratchbuf[0] = '$';
       print_operand_value (ins, ins->scratchbuf + 1, 1, cmp_type);
-      oappend_maybe_intel (ins, ins->scratchbuf);
+      oappend_immediate (ins, ins->scratchbuf);
       ins->scratchbuf[0] = '\0';
     }
 }
@@ -13532,7 +13681,7 @@ PCLMUL_Fixup (instr_info *ins, int bytemode ATTRIBUTE_UNUSED,
       /* We have a reserved extension byte.  Output it directly.  */
       ins->scratchbuf[0] = '$';
       print_operand_value (ins, ins->scratchbuf + 1, 1, pclmul_type);
-      oappend_maybe_intel (ins, ins->scratchbuf);
+      oappend_immediate (ins, ins->scratchbuf);
       ins->scratchbuf[0] = '\0';
     }
 }