From 9d1ce7321f27d47b76cba907127af777d6672188 Mon Sep 17 00:00:00 2001
From: "B. Watson" <urchlay@slackware.uk>
Date: Thu, 13 Jun 2024 15:30:33 -0400
Subject: major surgery: callback API, port dumpbas to use callbacks, add
 vxrefbas.

---
 vxrefbas.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)
 create mode 100644 vxrefbas.c

(limited to 'vxrefbas.c')

diff --git a/vxrefbas.c b/vxrefbas.c
new file mode 100644
index 0000000..839b776
--- /dev/null
+++ b/vxrefbas.c
@@ -0,0 +1,95 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <time.h>
+
+#include "bas.h"
+
+int target_var, lastline, assign, is_for, is_next;
+int refcounts[128];
+
+void print_help(void) {
+	fprintf(stderr, "Usage: %s program.bas\n", self);
+	exit(0);
+}
+
+CALLBACK(new_line) {
+	assign = is_for = is_next = 0;
+}
+
+CALLBACK(end_line) {
+	if(lastline != lineno) return;
+	printf("%d%s%s%s ",
+			lineno,
+			assign  ? "=" : "",
+			is_for  ? "{": "",
+			is_next ? "}": "");
+}
+
+CALLBACK(new_command) {
+	if(program[pos + 1] == (target_var | 0x80)) {
+		if(tok == CMD_LET || tok == CMD_ILET) {
+			assign = 1;
+		} else if(tok == CMD_FOR) {
+			is_for = 1;
+		} else if(tok == CMD_NEXT) {
+			is_next = 1;
+		}
+	}
+}
+
+CALLBACK(handle_var) {
+	if(lastline == lineno) return;
+	if((tok & 0x7f) == target_var) {
+		refcounts[target_var]++;
+		lastline = lineno;
+	}
+}
+
+int main(int argc, char **argv) {
+	unsigned short pos;
+	unsigned short vnpos;
+	int unref = 0;
+
+	set_self(*argv);
+	parse_general_args(argc, argv, print_help);
+
+	open_input(argv[1]);
+
+	readfile();
+	parse_header();
+
+	on_var_token = handle_var;
+	on_start_line = new_line;
+	on_end_line = end_line;
+	on_cmd_token = new_command;
+
+	target_var = 0;
+	vnpos = vnstart;
+
+	for(pos = vvstart; pos < codestart; pos += 8) {
+		/* print the variable name */
+		while(program[vnpos] < 0x80)
+			putchar(program[vnpos++]);
+		putchar(program[vnpos++] & 0x7f);
+		printf("/%02x: ", target_var | 0x80);
+
+		lastline = -1;
+		walk_all_code();
+
+		if(!refcounts[target_var]) {
+			unref++;
+			printf("(no references)");
+		} else {
+			printf("(%d)", refcounts[target_var]);
+		}
+		putchar('\n');
+
+		if(target_var++ == 128) break;
+	}
+
+	printf("  %d variables, %d unreferenced.\n", target_var, unref);
+	return 0;
+}
-- 
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