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diff lwlib/lw_expr.c @ 366:433dbc18fb41
Make byte overflow detection for 8 bit immediate not fail with COM operator
This is a horrible hack. Add a quick and dirty context to expression parsing
so that it knows whether an 8 bit or 16 bit complement is required. The 8
bit complement will just discard anything above bit 7. When returning an
operator back with lwasm_whichop(), the result will still be "COM" which
should allow other things to keep working as they already do.
This does prevent byte overflows when the complement operator is used,
however, and since those were introduced, there were problems building
Nitros9 among other things. This fix allows Nitros9 to build again.
author | William Astle <lost@l-w.ca> |
---|---|
date | Tue, 02 Jun 2015 20:58:14 -0600 |
parents | 12e2453f8417 |
children | 67373a053c49 |
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--- a/lwlib/lw_expr.c Tue Jun 02 20:08:58 2015 -0600 +++ b/lwlib/lw_expr.c Tue Jun 02 20:58:14 2015 -0600 @@ -40,6 +40,13 @@ static void (*divzero)(void *priv) = NULL; +static int expr_width = 0; + +void lw_expr_setwidth(int w) +{ + expr_width = w; +} + void lw_expr_setdivzero(void (*fn)(void *priv)) { divzero = fn; @@ -73,7 +80,11 @@ int lw_expr_whichop(lw_expr_t e) { if (e -> type == lw_expr_type_oper) + { + if (e -> value == lw_expr_oper_com8) + return lw_expr_oper_com; return e -> value; + } return -1; } @@ -202,7 +213,7 @@ case lw_expr_type_oper: t = va_arg(args, int); te1 = va_arg(args, lw_expr_t); - if (t != lw_expr_oper_com && t != lw_expr_oper_neg) + if (t != lw_expr_oper_com && t != lw_expr_oper_neg && t != lw_expr_oper_com8) te2 = va_arg(args, lw_expr_t); else te2 = NULL; @@ -321,6 +332,10 @@ case lw_expr_oper_com: strcat(buf, "COM "); break; + + case lw_expr_oper_com8: + strcat(buf, "COM8 "); + break; default: strcat(buf, "OPER "); @@ -715,6 +730,10 @@ tr = ~(E -> operands -> p -> value); break; + case lw_expr_oper_com8: + tr = ~(E -> operands -> p -> value) & 0xff; + break; + case lw_expr_oper_plus: tr = E -> operands -> p -> value; for (o = E -> operands -> next; o; o = o -> next) @@ -1187,7 +1206,10 @@ if (!term) return NULL; - term2 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_com, term); + if (expr_width == 8) + term2 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_com8, term); + else + term2 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_com, term); lw_expr_destroy(term); return term2; }