whichbas: much fancier BASIC/A+ detection (maybe too fancy?)

1 files changed, 100 insertions, 20 deletions

diff --git a/whichbas.c b/whichbas.c
index ec997cb..3a86c94 100644
--- a/whichbas.c
+++ b/whichbas.c
@@ -1045,41 +1045,121 @@ void check_variables(void) {
    surprise there)... but unlike Turbo, BXL, and BXE, it's *not*
    token-compatible with original Atari BASIC. Rather than add
    their new tokens to the end of the lists, they're mixed in with
-   the others. So A+ can't even LOAD or RUN Atari BASIC files. I
-   suppose the manual told you to LIST in BASIC, reboot, ENTER in
-   A+, to "port" your BASIC programs to A+.
+   the others. So A+ can't even LOAD or RUN Atari BASIC files.
+   Appendix J of the BASIC/A+ manual tells you to LIST in BASIC,
+   reboot, ENTER in A+, to "port" your BASIC programs to A+. I
+   suppose if you upgraded from A+ to BASIC XL or XE, you'd have
+   to do the same thing to use A+ programs in XL/XE.
 
    While this was probably a PITA for BASIC/A+ users back in the day,
    it makes it *really* easy to detect A+ here. The last line of
    every SAVEed program is the direct-mode command, and contains either
    a SAVE or CSAVE cmd token. Which is the same token in Atari, Turbo,
-   BXL, and BXE... but *different* in A+. */
+   BXL, and BXE... but *different* in A+.
+
+   However... I've run into at least one BASIC program in the Holmes
+   Archive that was missing its line 32768 (wish I could remember which).
+   And it's possible for files to get truncated... so I'll check a few
+   other command tokens, to deal with cases like this.
+ */
+void found_aplus(void) {
+	foreign("OSS BASIC/A+", SRET_APLUS);
+}
+
 CALLBACK(check_aplus_cmd) {
-	unsigned char nexttok;
-	int aplus_found = 0;
+	int has_args;
+	unsigned char nexttok, nexttok2;
 
 	nexttok = program[pos + 1];
+	nexttok2 = program[pos + 2];
+	has_args = !(nexttok == OP_EOS || nexttok == OP_EOL);
+	if(verbose) fprintf(stderr, "check_aplus_cmd: line %d, pos $%04x, tok $%02x, nexttok $%02x, nexttok2 $%02x\n", lineno, pos, tok, nexttok, nexttok2);
 
-	if(tok == 0x1d) {
-		/* SAVE in A+ (OP_STRCONST next).
-		   XIO in anything else (OP_HASH next). */
-		/* Note that A+ still uses the same tokens as BASIC for OP_STRCONST,
-		   OP_EOS, and OP_EOL. */
-		aplus_found = (nexttok == OP_STRCONST);
-	} else if(tok == 0x48) {
-		/* CSAVE in A+ (no arg).
-		   RND in anything else (OP_FUNC_LPAR next). */
-		aplus_found = (nexttok == OP_EOS || nexttok == OP_EOL);
-	}
+	switch(tok) {
+		case CMD_POP:      /* A+ READ */
+		case CMD_DOS:      /* A+ GET */
+		case CMD_DEG:      /* A+ WHILE */
+		case CMD_CLR:      /* A+ DIM */
+		case 0x46:         /* A+ SOUND <args>, Turbo LOOP, BXL/XE CP */
+			if(has_args)
+				found_aplus();
+			break;
+
+		case CMD_SAVE:     /* A+ END */
+		case CMD_GRAPHICS: /* A+ STOP */
+		case CMD_DIM:      /* A+ ENDWHILE */
+		case CMD_GET:      /* A+ RETURN */
+		case 0x38:         /* A+ DOS, Turbo DPOKE, BXL/XE WHILE */
+			if(!has_args)
+				found_aplus();
+			break;
 
-	if(aplus_found) {
-		foreign("OSS BASIC/A+", SRET_APLUS);
+		case CMD_POSITION: /* A+ ? */
+			/* PARTIAL: does nothing if 1st arg is numeric. */
+			if(!has_args)
+				/* POSITION can't have 0 args. */
+				found_aplus();
+			else if(is_string_rval(nexttok))
+				/* ? "STRING" or ? A$, e.g., can't be POSITION */
+				found_aplus();
+			else if(nexttok == OP_NUM_LE) /* numeric <= in BASIC, # in A+ */
+				found_aplus();
+			break;
+
+		case CMD_RUN: /* A+ PRINT */
+			/* PARTIAL: only detects PRINT # or PRINT <num> ... */
+			/* A+'s # token is BASIC's OP_NUM_LE! */
+			if(nexttok == OP_NUM_LE)
+				found_aplus();
+			else if(is_numconst_op(nexttok) || is_numeric_var(nexttok))
+				found_aplus();
+			break;
+
+		case CMD_XIO:    /* A+ SAVE */
+			/* most programs, this is enough, because they'll end with
+				32768 SAVE "D:BLAH" */
+			if(is_string_rval(nexttok))
+				found_aplus();
+			break;
+
+		case CMD_OPEN:   /* A+ ELSE */
+		/* case CMD_CLOSE: */  /* A+ DEG */ /* can't check, Turbo allows no args */
+		case CMD_STATUS: /* A+ NEW */
+		case CMD_POINT:  /* A+ LOAD */
+		case 0x42:       /* A+ POSITION, Turbo BPUT, BXL RGET */
+		case 0x43:       /* A+ DRAWTO, Turbo BGET, BXL BPUT */
+			if(nexttok != OP_HASH) /* # in BASIC, USING in A+ */
+				found_aplus();
+			break;
+
+		/* case 0x48: */ /* A+ CSAVE, Turbo DIR, BXL/BXE PROTECT */
+			/* DIR without arg is OK, so we can't really check this. */
+			/* break; */
+
+		case CMD_DRAWTO: /* A+ PUT */
+		case CMD_SOUND:  /* A+ RPUT */
+		case CMD_LPRINT: /* A+ RGET */
+		case CMD_CSAVE:  /* A+ BPUT */
+		case CMD_CLOAD:  /* A+ BGET */
+		case CMD_ON:     /* A+ STATUS */
+		case CMD_NOTE:   /* A+ OPEN */
+		case CMD_CONT:   /* A+ CLOSE */
+		case CMD_RAD:    /* A+ XIO */
+			if(nexttok == OP_NUM_LE) /* numeric <= in BASIC, # in A+ */
+				found_aplus();
+			break;
+
+		default: break;
 	}
+
+	last_cmd = tok;
 }
 
 void check_aplus(void) {
+	allow_hex_const = 1;
+
 	on_cmd_token = check_aplus_cmd;
-	walk_code(32768, 32768);
+	walk_all_code();
 }
 
 void check_atari_turbo_oss(void) {