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changeset 366:433dbc18fb41

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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 3f8abaac214c
children c6d2a1f54e0c
files lwasm/insn_gen.c lwasm/lwasm.c lwasm/lwasm.h lwasm/main.c lwlib/lw_expr.c lwlib/lw_expr.h
diffstat 6 files changed, 44 insertions(+), 5 deletions(-) [+]
line wrap: on
line diff
--- a/lwasm/insn_gen.c	Tue Jun 02 20:08:58 2015 -0600
+++ b/lwasm/insn_gen.c	Tue Jun 02 20:58:14 2015 -0600
@@ -323,7 +323,9 @@
 		lw_expr_t e;
 		
 		(*p)++;
+		as -> exprwidth = 8;
 		e = lwasm_parse_expr(as, p);
+		as -> exprwidth = 16;
 		if (!e)
 		{
 			lwasm_register_error(as, l, "Bad operand");
@@ -517,7 +519,9 @@
 	{
 		(*p)++;
 
+		as -> exprwidth = 8;
 		e = lwasm_parse_expr(as, p);
+		as -> exprwidth = 16;
 		if (!e)
 		{
 			lwasm_register_error(as, l, "Bad operand");
--- a/lwasm/lwasm.c	Tue Jun 02 20:08:58 2015 -0600
+++ b/lwasm/lwasm.c	Tue Jun 02 20:58:14 2015 -0600
@@ -732,9 +732,17 @@
 lw_expr_t lwasm_parse_expr(asmstate_t *as, char **p)
 {
 	lw_expr_t e;
-	
-	e = lw_expr_parse(p, as);
-	
+
+	if (as->exprwidth != 16)	
+	{
+		lw_expr_setwidth(as->exprwidth);
+		e = lw_expr_parse(p, as);
+		lw_expr_setwidth(0);
+	}
+	else
+	{
+		e = lw_expr_parse(p, as);
+	}
 	return e;
 }
 
--- a/lwasm/lwasm.h	Tue Jun 02 20:08:58 2015 -0600
+++ b/lwasm/lwasm.h	Tue Jun 02 20:58:14 2015 -0600
@@ -323,6 +323,7 @@
 	int passno;							// set to the current pass number
 	int preprocess;						// set if we are prepocessing
 	int fileerr;						// flags error opening file
+	int exprwidth;						// the bit width of the expression being evaluated
 };
 
 #ifndef ___symbol_c_seen___
--- a/lwasm/main.c	Tue Jun 02 20:08:58 2015 -0600
+++ b/lwasm/main.c	Tue Jun 02 20:58:14 2015 -0600
@@ -293,6 +293,7 @@
 	asmstate.input_files = lw_stringlist_create();
 	asmstate.nextcontext = 1;
 	asmstate.target = TARGET_6309;
+	asmstate.exprwidth = 16;
 	
 	/* parse command line arguments */	
 	lw_cmdline_parse(&cmdline_parser, argc, argv, 0, 0, &asmstate);
--- 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;
 	}
--- a/lwlib/lw_expr.h	Tue Jun 02 20:08:58 2015 -0600
+++ b/lwlib/lw_expr.h	Tue Jun 02 20:58:14 2015 -0600
@@ -51,6 +51,7 @@
 	lw_expr_oper_or,			// boolean or
 	lw_expr_oper_neg,			// unary negation, 2's complement
 	lw_expr_oper_com,			// unary 1's complement
+	lw_expr_oper_com8,			// 8 bit complement
 	lw_expr_oper_none = 0
 };
 
@@ -111,6 +112,8 @@
 
 extern int lw_expr_operandcount(lw_expr_t e);
 
+extern void lw_expr_setwidth(int w);
+
 // run a function on all terms in an expression; if the function
 // returns non-zero for any term, return non-zero, else return
 // zero