From fc5c53e5b73eeadafb20a5a02184642b9fcc8344 Mon Sep 17 00:00:00 2001
From: "B. Watson" <urchlay@slackware.uk>
Date: Fri, 7 Mar 2025 16:12:32 -0500
Subject: listamsb: add -D (decrunch) option.

---
 listamsb.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 94 insertions(+), 3 deletions(-)

(limited to 'listamsb.c')

diff --git a/listamsb.c b/listamsb.c
index 9acc300..be6b307 100644
--- a/listamsb.c
+++ b/listamsb.c
@@ -4,6 +4,7 @@
 #include <errno.h>
 #include <string.h>
 #include <stdarg.h>
+#include <ctype.h>
 
 #include "amsbtok.h"
 
@@ -81,7 +82,8 @@ int startline =   0;           /* -r */
 int endline   =   65536;       /* -r */
 int unlock_mode = 0;           /* -l */
 int initial_eol = 1;           /* -n */
-int crunch      = 0;           /* -C */
+int crunch      = 0;           /* -C, -D */
+int decrunch    = 0;           /* -D */
 
 int locked =      0;
 int need_pclose = 0;
@@ -478,6 +480,10 @@ void unlock_program(void) {
 	exit(0);
 }
 
+void write_code(int ptr, int lineno, const char *code) {
+	/* TODO */
+}
+
 int crunch_line(void) {
 	unsigned char code[MAX_LINE_LEN_HARD + 1], byte;
 	int lineno, ptr, codelen = 0, in_string = 0, in_comment = 0, commentstart = 0;
@@ -542,6 +548,89 @@ int crunch_line(void) {
 	return codelen;
 }
 
+void expand_token(unsigned char t, unsigned char *buf) {
+	if(t < 0x80) {
+		buf[0] = t;
+		buf[1] = 0;
+		return;
+	}
+
+	strcpy((char *)buf, std_tokens[t - MIN_STD_TOK]);
+}
+
+int need_space_between(unsigned char t1, unsigned char t2) {
+	unsigned char tok1[10], tok2[10];
+	unsigned char t1last, t2first;
+
+	if(!t1) return 0; /* start of line */
+	if(!t2) return 0; /* end of line */
+	if(t1 < 0x80 && t2 < 0x80) return 0; /* 2 ASCII chars */
+
+	expand_token(t1, tok1);
+	expand_token(t2, tok2);
+	t1last = tok1[strlen((char *)tok1) - 1]; /* "PRINT" => "T" */
+	t2first = tok2[0];               /* "PRINT" => "P" */
+
+	return(isalnum(t1last) && isalnum(t2first));
+}
+
+int decrunch_line(void) {
+	unsigned char code[MAX_LINE_LEN_HARD + 1], byte = 0, prev;
+	int lineno, ptr, codelen = 0, in_string = 0, in_comment = 0;
+	static int addr = 0x700; /* doesn't really matter where */
+
+	ptr = read_prog_word();
+	if(!ptr) return -1;
+	lineno = read_prog_word();
+
+	verbose(2, "decrunching line %d", lineno);
+
+	while(1) {
+		if(codelen >= MAX_LINE_LEN_HARD)
+			die("line %d too long, decrunching failed", lineno);
+		prev = byte;
+		byte = read_prog_byte();
+
+		if(byte != 0) {
+			if(in_string) {
+				if(byte == '|')
+					in_string = 0;
+			} else if(in_comment) {
+				/* NOP */
+			} else {
+				if(byte == '"') {
+					in_string = 1;
+				} else if(byte == TOK_REM || byte == TOK_SQUOTE || byte == TOK_BANG) {
+					in_comment = 1;
+				} else if(byte == 0xff) {
+					/* extended/function tokens never need a space before/after them */
+					code[codelen++] = byte;
+					byte = read_prog_byte();
+					code[codelen++] = byte;
+					byte = read_prog_byte();
+				} else if(need_space_between(prev, byte)) {
+					code[codelen++] = ' ';
+				}
+			}
+		}
+
+		code[codelen++] = byte;
+		if(byte == 0) break;
+	}
+
+	codelen += 4; /* account for ptr and lineno */
+	addr += codelen;
+
+	fputc(addr & 0xff, outfile);
+	fputc((addr >> 8) & 0xff, outfile);
+	fputc(lineno & 0xff, outfile);
+	fputc((lineno >> 8) & 0xff, outfile);
+	fputs((char *)code, outfile);
+	fputc(0x00, outfile);
+
+	return codelen;
+}
+
 void crunch_program(void) {
 	int newproglen = 0, linelen = 0;
 
@@ -549,7 +638,7 @@ void crunch_program(void) {
 	fputc(0x00, outfile); /* length LSB (fill in later) */
 	fputc(0x00, outfile); /* length MSB                 */
 
-	while((linelen = crunch_line()) != -1)
+	while((linelen = decrunch ? decrunch_line() : crunch_line()) != -1)
 		newproglen += linelen;
 
 	/* trailing $00 $00 */
@@ -578,6 +667,7 @@ void print_help(void) {
 	puts("  -a: raw ATASCII output");
 	puts("  -c: check only (no listing)");
 	puts("  -C: crunch program");
+	puts("  -D: decrunch program");
 	puts("  -l: lock or unlock program");
 	puts("  -n: no blank line at start of listing");
 	puts("  -v: verbosity");
@@ -638,8 +728,9 @@ void parse_args(int argc, char **argv) {
 		}
 	}
 
-	while( (opt = getopt(argc, argv, "Cnlr:cvaiutmsh")) != -1) {
+	while( (opt = getopt(argc, argv, "DCnlr:cvaiutmsh")) != -1) {
 		switch(opt) {
+			case 'D': crunch = decrunch = 1; break;
 			case 'C': crunch      = 1; break;
 			case 'l': unlock_mode = 1; break;
 			case 'c': check_only  = 1; break;
-- 
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