diff lwasm/struct.c @ 254:c7a41b4c89b3 2.x

Added struct support to LWASM
author lost
date Sat, 19 Dec 2009 06:38:43 +0000
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwasm/struct.c	Sat Dec 19 06:38:43 2009 +0000
@@ -0,0 +1,174 @@
+/*
+struct.c
+Copyright © 2009 William Astle
+
+This file is part of LWASM.
+
+LWASM 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/>.
+
+Contains stuff associated with structure definition.
+
+Structures have their own name space. Macros will shadow structures so it's
+a good idea to make sure no structures are name the same as macros.
+*/
+
+#include <config.h>
+
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include "lwasm.h"
+#include "instab.h"
+#include "util.h"
+
+OPFUNC(pseudo_struct)
+{
+	structtab_t *m;
+
+	// actually define a structure
+	if (as -> instruct)
+	{
+		register_error(as, l, 1, "Attempt to define a structure inside a structure");
+		return;
+ 	}
+
+	as -> instruct = 1;
+
+	// don't actually do anything if not pass 1
+	if (as -> passnum != 1)
+		return;
+
+
+	if (!l -> sym)
+	{
+		register_error(as, l, 1, "Structure definition with no effect - no symbol");
+		return;
+	}
+	
+	// search for macro by same name...
+	for (m = as -> structs; m; m = m -> next)
+	{
+		if (!strcmp(m -> name, l -> sym))
+			break;
+	}
+	if (m)
+	{
+		register_error(as, l, 1, "Duplicate structure definition");
+		return;
+	}
+	
+	m = lwasm_alloc(sizeof(structtab_t));
+	m -> name = lwasm_strdup(l -> sym);
+	m -> next = as -> structs;
+	m -> fields = NULL;
+	m -> size = 0;
+	as -> structs = m;
+	as -> cstruct = m;
+	
+	while (**p && !isspace(**p))
+		(*p)++;
+}
+
+
+
+pseudo_endstruct_aux(asmstate_t *as, lwasm_line_t *l, struct struct_sym_e *e, const char *prefix, int *coff)
+{
+	char *symname = NULL;
+	
+	while (e)
+	{
+		if (e -> name)
+			0 == asprintf(&symname, "%s.%s", prefix, e -> name);
+		else
+			0 == asprintf(&symname, "%s.___%d", prefix, *coff);
+		
+		// register symbol "symname" as global at coff
+		lwasm_register_symbol(as, l, symname, *coff, SYMBOL_NOCHECK);
+
+		if (e -> substruct)
+		{
+			char * t;
+			0 == asprintf(&t, "sizeof{%s}", symname);
+			lwasm_register_symbol(as, l, t, e -> substruct -> size, SYMBOL_NOCHECK);
+			lwasm_free(t);
+			pseudo_endstruct_aux(as, l, e -> substruct -> fields, symname, coff);
+		}
+		else
+		{
+			*coff += e -> size;
+		}
+
+		lwasm_free(symname);
+		e = e -> next;
+	}
+}
+
+OPFUNC(pseudo_endstruct)
+{
+	int coff = 0;
+	char *t;
+	
+	as -> instruct = 0;
+
+	if (as -> passnum != 1)
+		return;
+
+	// now register the global symbols for the structure
+	// this is a recursive process
+	0 == asprintf(&t, "sizeof{%s}", as -> cstruct -> name);
+	lwasm_register_symbol(as, l, t, as -> cstruct -> size, SYMBOL_NOCHECK);
+	lwasm_free(t);
+
+	pseudo_endstruct_aux(as, l, as -> cstruct -> fields, as -> cstruct -> name, &coff);
+}
+
+
+int expand_struct(asmstate_t *as, lwasm_line_t *l, char **p, char *opc)
+{
+	structtab_t *s;
+	int addr;
+	char *t;
+	
+	if (as -> passnum != 1)
+		return 0;
+	
+	for (s = as -> structs; s; s = s -> next)
+	{
+		if (!strcmp(opc, s -> name))
+			break;
+	}
+	if (!s)
+		return -1;
+
+	if (!(l -> sym))
+	{
+		register_error(as, l, 1, "Cannot declare a structure without a symbol name.");
+		return; 
+	}
+
+	l -> nocodelen = s -> size;
+
+	addr = as -> addr;
+	as -> addr += s -> size;
+	
+	// now register the global symbols for the structure
+	// this is a recursive process
+	0 == asprintf(&t, "sizeof{%s}", l -> sym);
+	lwasm_register_symbol(as, l, t, s -> size, SYMBOL_NOCHECK);
+	lwasm_free(t);
+
+	pseudo_endstruct_aux(as, l, s -> fields, l -> sym, &addr);
+	
+	return 0;
+}