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[patch][gas/z80] Prevent using register names as ordinary symbols
- From: Arnold Metselaar <arnold dot metselaar at planet dot nl>
- To: binutils at sourceware dot org
- Date: Sun, 6 May 2012 12:13:24 +0200
- Subject: [patch][gas/z80] Prevent using register names as ordinary symbols
Peter Hanzel has reported to me that z80-coff-as happily produces code
for pseudo instructions like LD HL,(SP+0).
Register names, like `SP' were only recognised when they appeared
alone in an argument or as part of standard indexed addressing
constructs, like `(ix+d)'.
This patch creates symbol table entries for z80 registers, preventing
their usage as ordinary symbols and bringing the parsing of them more
in line with other ports.
Changelog:
2012-05-06 Arnold Metselaar <arnold_m@operamail.com>
* config/tc-z80.h(md_register_arithmetic): Define as 0.
* config/tc-z80.c(md_begin): Store register names in symbol table,
prevents usage as ordinary symbol.
* config/tc-z80.c(contains_register): New function.
* config/tc-z80.c(parse_exp2): Removed.
* config/tc-z80.c(parse_exp_not_indexed): New function.
* config/tc-z80.c(parse_exp): Add code to recogize indexed
addressing after parsing.
* config/tc-z80.c(emit_byte, emit_word): Use contains_register.
* config/tc-z80.c(emit_jp): Use parse_exp_not_indexed, simplify
condition for jump to register.
* config/tc-z80.c(emit_call, emit_jr, emit_ex, emit_rst): Use
parse_exp_not_indexed.
Index: config/tc-z80.c
===================================================================
RCS file: /cvs/src/src/gas/config/tc-z80.c,v
retrieving revision 1.13
diff -u -p -r1.13 tc-z80.c
--- config/tc-z80.c 9 Dec 2010 20:02:07 -0000 1.13
+++ config/tc-z80.c 6 May 2012 09:28:51 -0000
@@ -1,5 +1,5 @@
/* tc-z80.c -- Assemble code for the Zilog Z80 and ASCII R800
- Copyright 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+ Copyright 2005, 2006, 2007, 2008, 2009, 2012 Free Software Foundation, Inc.
Contributed by Arnold Metselaar <arnold_m@operamail.com>
This file is part of GAS, the GNU Assembler.
@@ -161,12 +161,93 @@ Default: -z80 -ignore-undocument-instruc
static symbolS * zero;
+struct reg_entry
+{
+ char* name;
+ int number;
+};
+#define R_STACKABLE (0x80)
+#define R_ARITH (0x40)
+#define R_IX (0x20)
+#define R_IY (0x10)
+#define R_INDEX (R_IX | R_IY)
+
+#define REG_A (7)
+#define REG_B (0)
+#define REG_C (1)
+#define REG_D (2)
+#define REG_E (3)
+#define REG_H (4)
+#define REG_L (5)
+#define REG_F (6 | 8)
+#define REG_I (9)
+#define REG_R (10)
+
+#define REG_AF (3 | R_STACKABLE)
+#define REG_BC (0 | R_STACKABLE | R_ARITH)
+#define REG_DE (1 | R_STACKABLE | R_ARITH)
+#define REG_HL (2 | R_STACKABLE | R_ARITH)
+#define REG_IX (REG_HL | R_IX)
+#define REG_IY (REG_HL | R_IY)
+#define REG_SP (3 | R_ARITH)
+
+static const struct reg_entry regtable[] =
+{
+ {"a", REG_A },
+ {"af", REG_AF },
+ {"b", REG_B },
+ {"bc", REG_BC },
+ {"c", REG_C },
+ {"d", REG_D },
+ {"de", REG_DE },
+ {"e", REG_E },
+ {"f", REG_F },
+ {"h", REG_H },
+ {"hl", REG_HL },
+ {"i", REG_I },
+ {"ix", REG_IX },
+ {"ixh",REG_H | R_IX },
+ {"ixl",REG_L | R_IX },
+ {"iy", REG_IY },
+ {"iyh",REG_H | R_IY },
+ {"iyl",REG_L | R_IY },
+ {"l", REG_L },
+ {"r", REG_R },
+ {"sp", REG_SP },
+} ;
+
+#define BUFLEN 8 /* Large enough for any keyword. */
+
void
md_begin (void)
{
- expressionS nul;
+ expressionS nul, reg;
char * p;
+ unsigned int i, j, k;
+ char buf[BUFLEN];
+ reg.X_op = O_register;
+ reg.X_md = 0;
+ reg.X_add_symbol = reg.X_op_symbol = 0;
+ for ( i = 0 ; i < ARRAY_SIZE ( regtable ) ; ++i )
+ {
+ reg.X_add_number = regtable[i].number;
+ k = strlen ( regtable[i].name );
+ buf[k] = 0;
+ if ( k+1 < BUFLEN )
+ {
+ for ( j = ( 1<<k ) ; j ; --j )
+ {
+ for ( k = 0 ; regtable[i].name[k] ; ++k )
+ {
+ buf[k] = ( j & ( 1<<k ) ) ? TOUPPER ( regtable[i].name[k] ) : regtable[i].name[k];
+ }
+ symbolS * psym = symbol_find_or_make(buf);
+ S_SET_SEGMENT(psym, reg_section);
+ symbol_set_value_expression(psym, ®);
+ }
+ }
+ }
p = input_line_pointer;
input_line_pointer = "0";
nul.X_md=0;
@@ -343,63 +424,9 @@ key_cmp (const void * a, const void * b)
return strcmp (str_a, str_b);
}
-#define BUFLEN 8 /* Large enough for any keyword. */
-
char buf[BUFLEN];
const char *key = buf;
-#define R_STACKABLE (0x80)
-#define R_ARITH (0x40)
-#define R_IX (0x20)
-#define R_IY (0x10)
-#define R_INDEX (R_IX | R_IY)
-
-#define REG_A (7)
-#define REG_B (0)
-#define REG_C (1)
-#define REG_D (2)
-#define REG_E (3)
-#define REG_H (4)
-#define REG_L (5)
-#define REG_F (6 | 8)
-#define REG_I (9)
-#define REG_R (10)
-
-#define REG_AF (3 | R_STACKABLE)
-#define REG_BC (0 | R_STACKABLE | R_ARITH)
-#define REG_DE (1 | R_STACKABLE | R_ARITH)
-#define REG_HL (2 | R_STACKABLE | R_ARITH)
-#define REG_SP (3 | R_ARITH)
-
-static const struct reg_entry
-{
- char* name;
- int number;
-} regtable[] =
-{
- {"a", REG_A },
- {"af", REG_AF },
- {"b", REG_B },
- {"bc", REG_BC },
- {"c", REG_C },
- {"d", REG_D },
- {"de", REG_DE },
- {"e", REG_E },
- {"f", REG_F },
- {"h", REG_H },
- {"hl", REG_HL },
- {"i", REG_I },
- {"ix", REG_HL | R_IX },
- {"ixh",REG_H | R_IX },
- {"ixl",REG_L | R_IX },
- {"iy", REG_HL | R_IY },
- {"iyh",REG_H | R_IY },
- {"iyl",REG_L | R_IY },
- {"l", REG_L },
- {"r", REG_R },
- {"sp", REG_SP },
-} ;
-
/* Prevent an error on a line from also generating
a "junk at end of line" error message. */
static char err_flag;
@@ -496,88 +523,90 @@ is_indir (const char *s)
return indir;
}
-/* Parse general expression. */
+/* Check whether a symbol involves a register. */
+static int
+contains_register(symbolS *sym)
+{
+ if (sym)
+ {
+ expressionS * ex = symbol_get_value_expression(sym);
+ return (O_register == ex->X_op)
+ || (ex->X_add_symbol && contains_register(ex->X_add_symbol))
+ || (ex->X_op_symbol && contains_register(ex->X_op_symbol));
+ }
+ else
+ return 0;
+}
+
+/* Parse general expression, not loooking for indexed adressing. */
static const char *
-parse_exp2 (const char *s, expressionS *op, segT *pseg)
+parse_exp_not_indexed (const char *s, expressionS *op)
{
const char *p;
int indir;
- int i;
- const struct reg_entry * regp;
- expressionS offset;
+ segT dummy;
p = skip_space (s);
op->X_md = indir = is_indir (p);
- if (indir)
- p = skip_space (p + 1);
-
- for (i = 0; i < BUFLEN; ++i)
- {
- if (!ISALPHA (p[i])) /* Register names consist of letters only. */
- break;
- buf[i] = TOLOWER (p[i]);
- }
-
- if ((i < BUFLEN) && ((p[i] == 0) || (strchr (")+-, \t", p[i]))))
+ input_line_pointer = (char*) s ;
+ dummy = expression (op);
+ switch (op->X_op)
{
- buf[i] = 0;
- regp = bsearch (& key, regtable, ARRAY_SIZE (regtable),
- sizeof (regtable[0]), key_cmp);
- if (regp)
- {
- *pseg = reg_section;
- op->X_add_symbol = op->X_op_symbol = 0;
- op->X_add_number = regp->number;
- op->X_op = O_register;
- p += strlen (regp->name);
- p = skip_space (p);
- if (indir)
- {
- if (*p == ')')
- ++p;
- if ((regp->number & R_INDEX) && (regp->number & R_ARITH))
- {
- op->X_op = O_md1;
-
- if ((*p == '+') || (*p == '-'))
- {
- input_line_pointer = (char*) p;
- expression (& offset);
- p = skip_space (input_line_pointer);
- if (*p != ')')
- error (_("bad offset expression syntax"));
- else
- ++ p;
- op->X_add_symbol = make_expr_symbol (& offset);
- return p;
- }
-
- /* We treat (i[xy]) as (i[xy]+0), which is how it will
- end up anyway, unless we're processing jp (i[xy]). */
- op->X_add_symbol = zero;
- }
- }
- p = skip_space (p);
-
- if ((*p == 0) || (*p == ','))
- return p;
- }
+ case O_absent:
+ error (_("missing operand"));
+ break;
+ case O_illegal:
+ error (_("bad expression syntax"));
+ break;
}
- /* Not an argument involving a register; use the generic parser. */
- input_line_pointer = (char*) s ;
- *pseg = expression (op);
- if (op->X_op == O_absent)
- error (_("missing operand"));
- if (op->X_op == O_illegal)
- error (_("bad expression syntax"));
return input_line_pointer;
}
+/* Parse expression, change operator to O_md1 for indexed addressing*/
static const char *
parse_exp (const char *s, expressionS *op)
{
- segT dummy;
- return parse_exp2 (s, op, & dummy);
+ const char* res = parse_exp_not_indexed (s, op);
+ switch (op->X_op)
+ {
+ case O_add:
+ case O_subtract:
+ if (op->X_md && (O_register == symbol_get_value_expression(op->X_add_symbol)->X_op))
+ {
+ int rnum = symbol_get_value_expression(op->X_add_symbol)->X_add_number;
+ if ( ((REG_IX != rnum) && (REG_IY != rnum)) || contains_register(op->X_op_symbol) )
+ {
+ ill_op();
+ }
+ else
+ {
+ if (O_subtract == op->X_op)
+ {
+ expressionS minus;
+ minus.X_op = O_uminus;
+ minus.X_add_number = 0;
+ minus.X_add_symbol = op->X_op_symbol;
+ minus.X_op_symbol = 0;
+ op->X_op_symbol = make_expr_symbol(&minus);
+ op->X_op = O_add;
+ }
+ symbol_get_value_expression(op->X_op_symbol)->X_add_number += op->X_add_number;
+ op->X_add_number = rnum;
+ op->X_add_symbol = op->X_op_symbol;
+ op->X_op_symbol = 0;
+ op->X_op = O_md1;
+ }
+ }
+ break;
+ case O_register:
+ if ( op->X_md && ((REG_IX == op->X_add_number)||(REG_IY == op->X_add_number)) )
+ {
+ op->X_add_symbol = zero;
+ op->X_op = O_md1;
+ }
+ break;
+ }
+ return res;
}
/* Condition codes, including some synonyms provided by HiTech zas. */
@@ -680,7 +709,11 @@ emit_byte (expressionS * val, bfd_reloc_
p = frag_more (1);
*p = val->X_add_number;
- if ((r_type == BFD_RELOC_8_PCREL) && (val->X_op == O_constant))
+ if ( contains_register(val->X_add_symbol) || contains_register(val->X_op_symbol) )
+ {
+ ill_op();
+ }
+ else if ((r_type == BFD_RELOC_8_PCREL) && (val->X_op == O_constant))
{
as_bad (_("cannot make a relative jump to an absolute location"));
}
@@ -712,7 +745,9 @@ emit_word (expressionS * val)
p = frag_more (2);
if ( (val->X_op == O_register)
- || (val->X_op == O_md1))
+ || (val->X_op == O_md1)
+ || contains_register(val->X_add_symbol)
+ || contains_register(val->X_op_symbol) )
ill_op ();
else
{
@@ -888,7 +923,7 @@ emit_call (char prefix ATTRIBUTE_UNUSED,
expressionS addr;
const char *p; char *q;
- p = parse_exp (args, &addr);
+ p = parse_exp_not_indexed (args, &addr);
if (addr.X_md)
ill_op ();
else
@@ -936,7 +971,7 @@ emit_jr (char prefix ATTRIBUTE_UNUSED, c
const char *p;
char *q;
- p = parse_exp (args, &addr);
+ p = parse_exp_not_indexed (args, &addr);
if (addr.X_md)
ill_op ();
else
@@ -956,14 +991,11 @@ emit_jp (char prefix, char opcode, const
char *q;
int rnum;
- p = parse_exp (args, & addr);
+ p = parse_exp_not_indexed (args, & addr);
if (addr.X_md)
{
rnum = addr.X_add_number;
- if ((addr.X_op == O_register && (rnum & ~R_INDEX) == REG_HL)
- /* An operand (i[xy]) would have been rewritten to (i[xy]+0)
- in parse_exp (). */
- || (addr.X_op == O_md1 && addr.X_add_symbol == zero))
+ if ((O_register == addr.X_op) && (REG_HL == (rnum & ~R_INDEX)))
{
q = frag_more ((rnum & R_INDEX) ? 2 : 1);
if (rnum & R_INDEX)
@@ -1217,7 +1249,7 @@ emit_ex (char prefix_in ATTRIBUTE_UNUSED
const char * p;
char prefix, opcode;
- p = parse_exp (args, &op);
+ p = parse_exp_not_indexed (args, &op);
p = skip_space (p);
if (*p++ != ',')
{
@@ -1377,7 +1409,7 @@ emit_rst (char prefix ATTRIBUTE_UNUSED,
const char *p;
char *q;
- p = parse_exp (args, &addr);
+ p = parse_exp_not_indexed (args, &addr);
if (addr.X_op != O_constant)
{
error ("rst needs constant address");
Index: config/tc-z80.h
===================================================================
RCS file: /cvs/src/src/gas/config/tc-z80.h,v
retrieving revision 1.6
diff -u -p -r1.6 tc-z80.h
--- config/tc-z80.h 2 Sep 2009 07:24:21 -0000 1.6
+++ config/tc-z80.h 6 May 2012 09:28:51 -0000
@@ -1,5 +1,5 @@
/* this is tc-z80.h
- Copyright 2005, 2006, 2007 Free Software Foundation, Inc.
+ Copyright 2005, 2006, 2007, 2012 Free Software Foundation, Inc.
Contributed by Arnold Metselaar <arnold_m@operamail.com>
@@ -102,4 +102,8 @@ extern void z80_cons_fix_new (fragS *, i
P2VAR to the truncated power of two of sizes up to eight bytes. */
#define TC_IMPLICIT_LCOMM_ALIGNMENT(SIZE, P2VAR) (P2VAR) = 0
+/* It does not make any sense to perform arithmetic on the numbers
+ we use to identify registers. */
+#define md_register_arithmetic 0
+
#endif