s390: Enhance handling of syntax errors in assembler

Do not consume any unexpected character including newline ('\n') when
detecting a syntax error when parsing an operand block with parenthesis.
This resolves the unfavorable assembler messages from the example below,
including consuming the newline at the end of the current statement and
reporting the next statement as junk.

While at it change the only pre-increment of the current instruction
string pointer into a post-increment to align with the other instances.

Example assembler source:
	mvi	16(),32		# syntax error
	a	%r1,16(%r2	# syntax error
	a	%r1,16(%r2)
	mvc	16(1,),32(%r2)	# syntax error
	mvc	16(1,%r1,32(%r2	# syntax error

Assembler messages without commit:
1: Error: bad expression
1: Error: syntax error; missing ')' after base register
1: Error: syntax error; expected ','
1: Error: junk at end of line: `32'
2: Error: syntax error; missing ')' after base register
2: Error: junk at end of line: `a %r1,16(%r2)'
4: Error: bad expression
4: Error: syntax error; missing ')' after base register
4: Error: syntax error; expected ','
4: Error: operand out of range (32 is not between 0 and 15)
4: Error: syntax error; missing ')' after base register
4: Error: junk at end of line: `%r2)'
5: Error: syntax error; missing ')' after base register
5: Error: syntax error; expected ','
5: Error: operand out of range (32 is not between 0 and 15)
5: Error: syntax error; missing ')' after base register
5: Error: junk at end of line: `%r2'

Assembler messages with commit:
1: Error: bad expression
1: Error: syntax error; missing ')' after base register
2: Error: syntax error; missing ')' after base register
4: Error: bad expression
4: Error: syntax error; missing ')' after base register
5: Error: syntax error; missing ')' after base register
5: Error: syntax error; missing ')' after base register

gas/
	* config/tc-s390.c: Do not erroneously consume newline when
	parsing an addressing operand with parentheses.

Reviewed-by: Andreas Krebbel <krebbel@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/gas/config/tc-s390.c b/gas/config/tc-s390.c
index 1b7935a..019f26b 100644
--- a/gas/config/tc-s390.c
+++ b/gas/config/tc-s390.c
@@ -1526,8 +1526,10 @@ md_gather_operands (char *str,
       else if (operand->flags & S390_OPERAND_BASE)
 	{
 	  /* After the base register the parenthesised block ends.  */
-	  if (*str++ != ')')
+	  if (*str != ')')
 	    as_bad (_("syntax error; missing ')' after base register"));
+	  else
+	    str++;
 	  skip_optional = 0;
 
 	  if (*str == '\0' && skip_optargs_p (opcode->flags, &opindex_ptr[1]))
@@ -1584,7 +1586,7 @@ md_gather_operands (char *str,
     }
 
   while (ISSPACE (*str))
-    ++str;
+    str++;
 
   /* Check for tls instruction marker.  */
   reloc = s390_tls_suffix (&str, &ex);