Re: gas .macro quirks, and an ARM bug

[Ulf Carlsson <ulfc at calypso dot engr dot sgi dot com>]

Hi Nick,

> : No, this was intentional.  The only problem I see with the current
> : implementation is that you actually can't pass a `\"' through it if
> : you really want a quote character in your string.
> : 
> :         .macro  hello   narg1
> :                 .asciiz  "\narg1"
> :         .endm
> :         hello   "a quote char: \""
> : 
> : This assembles into
> : 
> : 	Contents of section .text:
> : 	 0000 61207175 6f746520 63686172 3a202200  a quote char: ".
> : 	Contents of section .data:
> : 
> : You can probably get the same effect by passing `\\"' with your patch, but I
> : think that's even more obscure since expansion of escape sequences usually
> : isn't done in arguments to macros.  The logical syntax would have
> : been `\\\"'. 
> 
> Good point.  OK I agree that your patch is the correct solution,
> although we still need to add one small extra test, to make sure that
> the character following the backslash is actually present:

Forget my last mail.  I wasn't thinking and things were a bit more complicated
than I first thought.  This patch can assemble

        .macro  hello   narg1
                .asciiz  "\narg1"
        .endm
        hello   " \\\"foo\\\""

into this

	ontents of section .text:
	 0000 205c2266 6f6f5c22 00000000 00000000   \"foo\"........
	Contents of section .data:

Ulf

Index: macro.c
===================================================================
RCS file: /cvs/src/src/gas/macro.c,v
retrieving revision 1.7
diff -u -p -r1.7 macro.c
--- macro.c	2000/05/01 14:01:06	1.7
+++ macro.c	2000/06/08 21:14:23
@@ -304,13 +304,24 @@ getstring (idx, in, acc)
       else if (in->ptr[idx] == '"' || in->ptr[idx] == '\'')
 	{
 	  char tchar = in->ptr[idx];
+	  int escaped = 0;
 	  idx++;
 	  while (idx < in->len)
 	    {
+	      if (in->ptr[idx-1] == '\\')
+		escaped ^= 1;
+	      else
+		escaped = 0;
+
 	      if (macro_alternate && in->ptr[idx] == '!')
 		{
 		  idx++  ;
 		  sb_add_char (acc, in->ptr[idx++]);
+		}
+	      else if (escaped && in->ptr[idx] == tchar)
+		{
+		  sb_add_char (acc, tchar);
+		  idx++;
 		}
 	      else
 		{