diff lwasm/pass4.c @ 0:2c24602be78f

Initial import from lwtools 3.0.1 version, with new hand built build system and file reorganization
author lost@l-w.ca
date Wed, 19 Jan 2011 22:27:17 -0700
parents
children 697bc543368c
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwasm/pass4.c	Wed Jan 19 22:27:17 2011 -0700
@@ -0,0 +1,127 @@
+/*
+pass4.c
+
+Copyright © 2010 William Astle
+
+This file is part of LWTOOLS.
+
+LWTOOLS is free software: you can redistribute it and/or modify it under the
+terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later
+version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+more details.
+
+You should have received a copy of the GNU General Public License along with
+this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <stdio.h>
+#include <string.h>
+
+#include <lw_alloc.h>
+#include <lw_string.h>
+
+#include "lwasm.h"
+#include "instab.h"
+
+/*
+Resolve2 Pass
+
+Force resolution of instruction sizes.
+
+*/
+void do_pass4_aux(asmstate_t *as, int force)
+{
+	int rc;
+	int cnt;
+	line_t *cl, *sl;
+	struct line_expr_s *le;
+
+	// first, count the number of unresolved instructions
+	for (cnt = 0, cl = as -> line_head; cl; cl = cl -> next)
+	{
+		if (cl -> len == -1)
+			cnt++;
+	}
+
+	sl = as -> line_head;
+	while (cnt > 0)
+	{
+		// find an unresolved instruction
+		for ( ; sl && sl -> len != -1; sl = sl -> next)
+		{
+			as -> cl = sl;
+			lwasm_reduce_expr(as, sl -> addr);
+		
+			// simplify each expression
+			for (le = sl -> exprs; le; le = le -> next)
+				lwasm_reduce_expr(as, le -> expr);
+		}
+				
+		// simplify address
+		as -> cl = sl;
+		lwasm_reduce_expr(as, sl -> addr);
+		
+		// simplify each expression
+		for (le = sl -> exprs; le; le = le -> next)
+			lwasm_reduce_expr(as, le -> expr);
+
+
+		if (sl -> len == -1 && sl -> insn >= 0 && instab[sl -> insn].resolve)
+		{
+			(instab[sl -> insn].resolve)(as, sl, 1);
+			if (force && sl -> len == -1)
+			{
+				lwasm_register_error(as, sl, "Instruction failed to resolve.");
+				return;
+			}
+		}
+		cnt--;
+		if (cnt == 0)
+			return;
+
+		do
+		{
+			rc = 0;
+			for (cl = sl; cl; cl = cl -> next)
+			{
+				as -> cl = cl;
+			
+				// simplify address
+				lwasm_reduce_expr(as, cl -> addr);
+		
+				// simplify each expression
+				for (le = cl -> exprs; le; le = le -> next)
+					lwasm_reduce_expr(as, le -> expr);
+			
+				if (cl -> len == -1)
+				{
+					// try resolving the instruction length
+					// but don't force resolution
+					if (cl -> insn >= 0 && instab[cl -> insn].resolve)
+					{
+						(instab[cl -> insn].resolve)(as, cl, 0);
+						if (cl -> len != -1)
+						{
+							rc++;
+							cnt--;
+							if (cnt == 0)
+								return;
+						}
+					}
+				}
+			}
+			if (as -> errorcount > 0)
+				return;
+		} while (rc > 0);
+	}
+}
+
+void do_pass4(asmstate_t *as)
+{
+	do_pass4_aux(as, 1);
+}