FreeCalypso > hg > freecalypso-tools
view librftab/rftablerd.c @ 465:003e48f8ebe1
rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel
I generally don't use NULL and use plain 0 instead, based on a "NULL
considered harmful" discussion on the classiccmp mailing list many aeons
ago (I couldn't find it, and I reason that it must have been 2005 or
earlier), but a recent complaint by a packager sent me searching, and I
found this:
https://ewontfix.com/11/
While I don't give a @#$% about "modern" systems and code-nazi tools,
I realized that passing a plain 0 as a pointer sentinel in execl is wrong
because it will break on systems where pointers are longer than the plain
int type. Again, I don't give a @#$% about the abomination of x86_64 and
the like, but if anyone ever manages to port my code to something like a
PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0
as a function argument where a pointer is expected most definitely won't
work: if the most natural stack slot and SP alignment unit is 16 bits,
fitting an int, with longs and pointers taking up two such slots, then
the call stack will be totally wrong with a plain 0 passed for a pointer.
Casting the 0 to (char *) ought to be the most kosher solution for the
most retro systems possible.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 11 Feb 2019 00:00:19 +0000 |
parents | a0f79bba0ad8 |
children | 059649902c7f |
line wrap: on
line source
/* * Reading RF tables from formatted ASCII files: used for the rftw command * in fc-tmsh, for the upload-rf-table command in fc-fsio, and in the * standalone fc-cal2bin utility. */ #include <sys/types.h> #include <ctype.h> #include <stdio.h> #include <string.h> #include <strings.h> #include <stdlib.h> #include "../rvinterf/include/exitcodes.h" #include "rdcommon.c" static char *format; static u_char *writeptr; static unsigned written_size, maxsize; static process_number(size) { char *field; int rc; u_long number; rc = get_field(&field); if (rc < 0) return(ERROR_USAGE); if (!rc) { printf("error: %s is too short for table format %s\n", filename, format); return(ERROR_USAGE); } if (field[0] == '-') number = strtol(field, 0, 0); else number = strtoul(field, 0, 0); switch (size) { case 1: *writeptr++ = number; break; case 2: *writeptr++ = number; *writeptr++ = number >> 8; break; case 4: *writeptr++ = number; *writeptr++ = number >> 8; *writeptr++ = number >> 16; *writeptr++ = number >> 24; break; default: abort(); } written_size += size; return(0); } static expect_keyword(kw) char *kw; { char *field; int rc; rc = get_field(&field); if (rc < 0) return(ERROR_USAGE); if (!rc) { printf("error: %s is too short for table format %s\n", filename, format); return(ERROR_USAGE); } if (strcmp(field, kw)) { printf("%s line %d: expected %s keyword\n", filename, lineno, kw); return(ERROR_USAGE); } return(0); } static ensure_eof() { char *field; int rc; rc = get_field(&field); if (rc < 0) return(ERROR_USAGE); if (rc) { printf("error: %s is too long for table format %s\n", filename, format); return(ERROR_USAGE); } return(0); } static read_agc_table() { int i, rc; for (i = 0; i < 20; i++) { rc = process_number(2); if (rc) return(rc); } return ensure_eof(); } static read_afcparams() { int i, rc; for (i = 0; i < 4; i++) { rc = process_number(4); if (rc) return(rc); } for (i = 0; i < 4; i++) { rc = process_number(2); if (rc) return(rc); } return ensure_eof(); } static read_agc_global_params() { int i, rc; for (i = 0; i < 4; i++) { rc = process_number(2); if (rc) return(rc); } return ensure_eof(); } static read_il2agc() { int i, rc; for (i = 0; i < 121; i++) { rc = process_number(1); if (rc) return(rc); } return ensure_eof(); } static read_tx_ramps() { int i, j, rc; if (maxsize < 512) { printf("error: tx-ramps table not allowed in this context\n"); return(ERROR_USAGE); } for (i = 0; i < 16; i++) { rc = expect_keyword("ramp-up"); if (rc) return(rc); for (j = 0; j < 16; j++) { rc = process_number(1); if (rc) return(rc); } rc = expect_keyword("ramp-down"); if (rc) return(rc); for (j = 0; j < 16; j++) { rc = process_number(1); if (rc) return(rc); } } return ensure_eof(); } static read_tx_levels() { int i, rc; for (i = 0; i < 32; i++) { rc = process_number(2); if (rc) return(rc); rc = process_number(1); if (rc) return(rc); rc = process_number(1); if (rc) return(rc); } return ensure_eof(); } static read_tx_calchan() { int i, rc; for (i = 0; i < 64; i++) { rc = process_number(2); if (rc) return(rc); } return ensure_eof(); } static read_tx_caltemp() { int i, rc; for (i = 0; i < 20; i++) { rc = process_number(2); if (rc) return(rc); } return ensure_eof(); } static read_rx_calchan() { int i, rc; for (i = 0; i < 20; i++) { rc = process_number(2); if (rc) return(rc); } return ensure_eof(); } static read_rx_caltemp() { int i, rc; for (i = 0; i < 22; i++) { rc = process_number(2); if (rc) return(rc); } return ensure_eof(); } static read_rx_agc_params() { int i, rc; for (i = 0; i < 4; i++) { rc = process_number(2); if (rc) return(rc); } return ensure_eof(); } static read_raw_table() { int rc; char *field; u_long number; for (;;) { rc = get_field(&field); if (rc < 0) return(ERROR_USAGE); if (!rc) break; number = strtoul(field, 0, 16); if (written_size >= maxsize) { printf("error: raw table %s exceeds maximum size\n", filename); return(ERROR_USAGE); } *writeptr++ = number; written_size++; } if (!written_size) { printf("error: raw table %s is empty\n", filename); return(ERROR_USAGE); } return(0); } static struct table_format { char *kw; int (*handler)(); } table_formats[] = { {"agc-table", read_agc_table}, {"afcparams", read_afcparams}, {"agc-global-params", read_agc_global_params}, {"il2agc", read_il2agc}, {"tx-ramps", read_tx_ramps}, {"tx-levels", read_tx_levels}, {"tx-calchan", read_tx_calchan}, {"tx-caltemp", read_tx_caltemp}, {"rx-calchan", read_rx_calchan}, {"rx-caltemp", read_rx_caltemp}, {"rx-agc-params", read_rx_agc_params}, {"raw", read_raw_table}, {0, 0} }; read_rf_table_ext(filename_arg, rdbuf, allow_large, format_ret, size_ret) char *filename_arg; u_char *rdbuf; char **format_ret; unsigned *size_ret; { char *field; int rc; struct table_format *tp; filename = filename_arg; rdfile = fopen(filename, "r"); if (!rdfile) { perror(filename); return(ERROR_UNIX); } lineno = 0; line_nfields = 0; rc = get_field(&field); if (rc <= 0) { not_valid_rftable: printf("error: %s is not a valid RF table file\n", filename); fclose(rdfile); return(ERROR_USAGE); } if (strcmp(field, "rf_table")) goto not_valid_rftable; rc = get_field(&field); if (rc <= 0) goto not_valid_rftable; for (tp = table_formats; tp->kw; tp++) if (!strcmp(tp->kw, field)) break; if (!tp->kw) { printf("error: table format \"%s\" not recognized\n", field); fclose(rdfile); return(ERROR_USAGE); } format = tp->kw; if (format_ret) *format_ret = format; writeptr = rdbuf; written_size = 0; if (allow_large) maxsize = 512; else maxsize = 128; rc = tp->handler(); fclose(rdfile); if (size_ret) *size_ret = written_size; return(rc); }