diff options
| -rw-r--r-- | unprotbas.c | 35 |
1 files changed, 23 insertions, 12 deletions
diff --git a/unprotbas.c b/unprotbas.c index bf8fc76..acfd528 100644 --- a/unprotbas.c +++ b/unprotbas.c @@ -15,7 +15,9 @@ or whatever), we "fix" that by making up new variable names. */ -#define STM_OFFSET 0xf2 +/* the difference between the VVTP and VNTP values in the file, and the + actual file positions of the variable names and values. */ +#define TBL_OFFSET 0xf2 /* minimum program size, for a program that has no variables and only one line of code (the immediate line 32768, consisting only of @@ -23,14 +25,22 @@ can't process. */ #define MIN_PROG_SIZE 21 -#define MAP_FILE "varnames.txt" +/* maximum size of the program in memory. 64KB is actually way overkill. */ +#define BUFSIZE 65536 + +/* maximum number of variables in the variable name and value tables. this + could be 128, but "ERROR- 4" still expands the tables. Entries >128 + don't have tokens, can't be referred to in code, but we'll preserve + them anyway. */ +#define MAXVARS 256 /* entire file gets read into memory (for now) */ -unsigned char data[65536]; +unsigned char data[BUFSIZE]; /* for the -r option */ -unsigned char varnames[65536]; -unsigned char *varmap[256]; +#define MAP_FILE "varnames.txt" +unsigned char varnames[BUFSIZE]; +unsigned char *varmap[MAXVARS]; int varmap_count; /* BASIC 14-byte header values */ @@ -108,9 +118,9 @@ void read_header(void) { stmtab = getword(8); stmcur = getword(10); starp = getword(12); - codestart = stmtab - STM_OFFSET - (vntp - 256); - vnstart = vntp - 256 + 14; - vvstart = vvtp - 256 + 14; + codestart = stmtab - TBL_OFFSET - (vntp - 256); + vnstart = vntp - TBL_OFFSET; + vvstart = vvtp - TBL_OFFSET; if(verbose) dump_header_vars(); } @@ -294,6 +304,7 @@ void move_code(int offset) { or letter+number or one-letter string/array names). */ +/* return true if the variable name table is OK */ int vntable_ok(void) { int vp, bad; @@ -355,8 +366,8 @@ int rebuild_vntable(int write) { unsigned char type = data[vv] >> 6; /* fprintf(stderr, "%04x: %04x, %d\n", vv, data[vv], type); */ - if(varnum == 256) { - fprintf(stderr, "Warning: skipping variable numbers >=256 in value table.\n"); + if(varnum == MAXVARS) { + fprintf(stderr, "Warning: skipping variable numbers >=%d in value table.\n", MAXVARS); break; } @@ -396,7 +407,7 @@ int rebuild_vntable(int write) { } /* there's supposed to be a null byte at the end of the table, unless - all 128 table slots are used... except really, there can be 129 + all 128 table slots are used... except really, there can be >=129 entries, and there's always a null byte. */ if(write) data[vp] = 0; size++; @@ -560,7 +571,7 @@ void read_var_map(void) { } void apply_var_map(void) { - unsigned char new_vntable[65536]; + unsigned char new_vntable[BUFSIZE]; int i, newp = 0; unsigned char *v; |