andrew/piquant
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WIP Immediate mode, printing, and listing is working, but something wierd is going on with _cputs. See the comment in basic_cmd_list. I'm tempted to throw the C away and move it all to ASM so I can have more control & awareness of what's going on.

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This commit is contained in:
Andrew Kesterson
2024-05-07 18:55:59 -04:00
parent 06d110e28b
commit 0826d1946b
1 changed files with 15 additions and 290 deletions
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305
src/basic.c
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@@ -17,7 +17,8 @@ char *_tokenizer_prev;
char *_tokenizer_prev_next;
char basic_memory_lines[BASIC_MAX_LINES][BASIC_MAX_LINE_LENGTH];
char decimal[32];
char const_string_test[255];
void basic_report_error(char *prefix)
{
memset((char *)&decimal, 0x00, 32);
@@ -45,7 +46,12 @@ void basic_cmd_list(void *data)
char *lineptr = NULL;
i = 0;
_cputs("OMG WTF BBQ\n");
/* I don't know why, but somehow, this makes the interspersed _cputs() calls below work.
* Take this out, and those lines stop working.
* WHAT. THE. FUCK.
*/
memcpy((char *)&const_string_test, (char *)"OMG WTF BBQ\n\0", strlen("OMG WTF BBQ\n\0"));
_cputs((char *)&const_string_test);
for ( i = 0; i <= limit ; i++ ) {
lineptr = basic_memory_line_address(i);
if ( lineptr == NULL ) {
@@ -70,19 +76,7 @@ void basic_cmd_print(void *data)
return;
}
expr = basic_parse_expr((char *)data, 0);
if ( expr == NULL ) {
basic_errno = BASIC_ERR_INTERNAL_NULLPOINTER;
return;
}
memset((void *)&result, 0x00, sizeof(struct basic_variable));
basic_solve_expr(expr, &result);
if ( basic_errno != 0 ) {
return;
} else {
basic_print_var(&result);
}
_cputs((char *)data);
}
void basic_cmd_run(void *data)
@@ -192,11 +186,14 @@ int basic_memory_line_store(char *content, int lineno)
dest = basic_memory_line_address(lineno);
if ( lineno > basic_last_stored_lineno ) {
/* The memory between here and there is probably uninitialized. When we come back
/*
* basic_last_stored_lineno only every grows upward (even if you go back and edit a line or insert one).
* The memory between here (new line) and there (last line) is probably uninitialized. When we come back
* through to LIST those lines later we may find garbage. Let's clean it up.
*/
for ( i = basic_last_stored_lineno+1; i <= lineno ; i++ ) {
ptr = basic_memory_line_address(i);
/* We don't need to zero the entire string, just the first character, don't waste time */
memset(ptr, 0x00, BASIC_MAX_LINE_LENGTH);
}
}
@@ -209,232 +206,6 @@ int basic_memory_line_store(char *content, int lineno)
basic_last_stored_lineno = lineno;
}
int basic_solve_expr(struct basic_expr *expr, struct basic_variable *result)
{
if ( expr == NULL || result == NULL ) {
basic_errno = BASIC_ERR_INTERNAL_NULLPOINTER;
return 0;
}
switch (expr->type) {
case BASIC_OPTP_NONE:
if ( expr->lval_type == BASIC_LVAL_CONST_INT ) {
result->flags = (result->flags | BASIC_VARFLAG_TINT | BASIC_VARFLAG_INIT);
result->value.i = expr->lval.i;
} else if ( expr->lval_type == BASIC_LVAL_CONST_STR ) {
result->flags = (result->flags | BASIC_VARFLAG_TSTR | BASIC_VARFLAG_INIT);
result->value.str = (char *)expr->lval.ptr;
} else {
basic_errno = BASIC_ERR_INTERNAL_UNIMPLEMENTED;
return 0;
}
break;
case BASIC_OPTP_ADD:
if ( expr->lval_type != BASIC_LVAL_CONST_INT ||
( expr->rval_type != BASIC_RVAL_CONST_INT ) ) {
basic_errno = BASIC_ERR_INVALID_ARGUMENTS;
return 0;
}
result->flags = (result->flags | BASIC_VARFLAG_TINT | BASIC_VARFLAG_INIT);
result->value.i = expr->lval.i + expr->rval.i;
break;
case BASIC_OPTP_SUB:
if ( expr->lval_type != BASIC_LVAL_CONST_INT ||
( expr->rval_type != BASIC_RVAL_CONST_INT ) ) {
basic_errno = BASIC_ERR_INVALID_ARGUMENTS;
return 0;
}
result->flags = (result->flags | BASIC_VARFLAG_TINT | BASIC_VARFLAG_INIT);
result->value.i = expr->lval.i - expr->rval.i;
break;
case BASIC_OPTP_MUL:
if ( expr->lval_type != BASIC_LVAL_CONST_INT ||
( expr->rval_type != BASIC_RVAL_CONST_INT ) ) {
basic_errno = BASIC_ERR_INVALID_ARGUMENTS;
return 0;
}
result->flags = (result->flags | BASIC_VARFLAG_TINT | BASIC_VARFLAG_INIT);
result->value.i = expr->lval.i * expr->rval.i;
break;
case BASIC_OPTP_DIV:
if ( expr->lval_type != BASIC_LVAL_CONST_INT ||
( expr->rval_type != BASIC_RVAL_CONST_INT ) ) {
basic_errno = BASIC_ERR_INVALID_ARGUMENTS;
return 0;
}
if ( expr->rval.i == 0) {
basic_errno = BASIC_ERR_MATH_DBZ;
return 0;
}
result->flags = (result->flags | BASIC_VARFLAG_TINT | BASIC_VARFLAG_INIT);
result->value.i = expr->lval.i / expr->rval.i;
break;
case BASIC_OPTP_MOD:
if ( expr->lval_type != BASIC_LVAL_CONST_INT ||
( expr->rval_type != BASIC_RVAL_CONST_INT ) ) {
basic_errno = BASIC_ERR_INVALID_ARGUMENTS;
return 0;
}
if ( expr->rval.i == 0) {
basic_errno = BASIC_ERR_MATH_DBZ;
return 0;
}
result->flags = (result->flags | BASIC_VARFLAG_TINT | BASIC_VARFLAG_INIT);
result->value.i = (expr->lval.i) - ((expr->lval.i / expr->rval.i)*expr->rval.i);
break;
case BASIC_OPTP_EQL:
if ( expr->lval_type != BASIC_LVAL_CONST_INT ||
( expr->rval_type != BASIC_RVAL_CONST_INT ) ) {
basic_errno = BASIC_ERR_INVALID_ARGUMENTS;
return 0;
}
result->flags = (result->flags | BASIC_VARFLAG_TINT | BASIC_VARFLAG_INIT);
if (expr->lval.i == expr->rval.i) {
result->value.i = BASIC_CONST_TRUE;
} else {
result->value.i = BASIC_CONST_FALSE;
}
break;
case BASIC_OPTP_STOR:
/* this funky pointer dereferencing is to make bcc happy, it can't
* manage indexing the array and dereferencing that */
if ( memcpy(
basic_memory_line_address(expr->lval.i-1),
(char *)expr->rval.ptr,
strlen((char *)expr->rval.ptr)
) == NULL ) {
basic_errno = BASIC_ERR_INTERNAL_NULLPOINTER;
return 0;
}
result->flags = (result->flags | BASIC_VARFLAG_TSTR | BASIC_VARFLAG_INIT);
result->value.ptr = BASIC_MESSAGE_OK;
basic_last_stored_lineno = expr->lval.i-1;
break;
case BASIC_OPTP_ASN:
basic_errno = BASIC_ERR_INTERNAL_UNIMPLEMENTED;
return 0;
default:
basic_errno = BASIC_ERR_INTERNAL_UNDEFINED_BEHAVIOR;
return 0;
}
return 1;
}
struct basic_expr *basic_parse_expr(char *expbuf, int require_line_numbers)
{
struct basic_expr *ret = &math_expressions[0];
char *token = NULL;
char flags = 0;
if ( require_line_numbers == 1 ) {
flags = BASIC_PARSE_FIRSTTOKEN;
}
/*char *subptr = 0;*/
_tokenizer_init();
memset(ret, 0x0, sizeof(struct basic_expr));
while ( *expbuf != '\0' ) {
if ( *expbuf == ' ' ) {
expbuf += 1;
continue;
}
expbuf = _tokenize(expbuf, " ");
token = tokenizer_token();
if ( isdigit(*token) == 1 ) {
if ( flags == BASIC_PARSE_FIRSTTOKEN ) {
ret->type = BASIC_OPTP_STOR;
ret->lval_type = BASIC_LVAL_CONST_INT;
ret->lval.i = atoi(token);
ret->rval.ptr = expbuf;
ret->rval_type = BASIC_RVAL_PTR;
break;
}
if ( (ret->type == 0) && (flags & BASIC_PARSE_FOUND_LVAL) == BASIC_PARSE_FOUND_LVAL ) {
basic_errno = BASIC_ERR_SYNTAX_MULTIPLE_LVALUES;
return NULL;
} else if ( ret->type == 0x0 ) {
ret->lval.i = atoi(token);
ret->lval_type = BASIC_LVAL_CONST_INT;
flags = (flags | BASIC_PARSE_FOUND_LVAL);
} else if ( ret->type != 0x0 && ((flags & BASIC_PARSE_FOUND_RVAL) == BASIC_PARSE_FOUND_RVAL)) {
basic_errno = BASIC_ERR_SYNTAX_MULTIPLE_RVALUES;
return NULL;
} else if ( ret->type != 0x0 ) {
ret->rval.i = atoi(token);
ret->rval_type = BASIC_RVAL_CONST_INT;
}
} else if ( token != NULL && ret->type == 0x0 ) {
if ( flags == BASIC_PARSE_FIRSTTOKEN ) {
basic_errno = BASIC_ERR_SYNTAX_NO_LINE_NUMBER;
}
switch ( *token ) {
case '+':
ret->type = BASIC_OPTP_ADD;
break;
case '*':
ret->type = BASIC_OPTP_MUL;
break;
case '-':
ret->type = BASIC_OPTP_SUB;
break;
case '/':
ret->type = BASIC_OPTP_DIV;
break;
case '%':
ret->type = BASIC_OPTP_MOD;
break;
default:
/* see if a command will claim this token */
if ( strcmp(token, "REM") == 0 ) {
ret->type = BASIC_OPTP_CMD;
ret->lval_type = BASIC_LVAL_CMDPTR;
ret->lval.cmd_ptr = basic_cmd_rem;
ret->rval_type = BASIC_RVAL_NONE;
return ret;
} else if ( strcmp(token, "PRINT") == 0 ) {
ret->type = BASIC_OPTP_CMD;
ret->lval_type = BASIC_LVAL_CMDPTR;
ret->lval.cmd_ptr = basic_cmd_print;
ret->rval_type = BASIC_RVAL_PTR;
ret->rval.ptr = expbuf;
return ret;
} else if ( strcmp(token, "LIST") == 0 ) {
ret->type = BASIC_OPTP_CMD;
ret->lval_type = BASIC_LVAL_CMDPTR;
ret->lval.cmd_ptr = basic_cmd_list;
ret->rval_type = BASIC_RVAL_PTR;
ret->rval.ptr = expbuf;
return ret;
} else if ( strcmp(token, "RUN") == 0 ) {
ret->type = BASIC_OPTP_CMD;
ret->lval_type = BASIC_LVAL_CMDPTR;
ret->lval.cmd_ptr = basic_cmd_run;
ret->rval_type = BASIC_RVAL_PTR;
ret->rval.ptr = expbuf;
return ret;
} else {
/*
* For now just treat it like a string constant and we'll improve this later
*
* basic_errno = BASIC_ERR_SYNTAX_GENERAL;
* return NULL;
*/
ret->lval_type = BASIC_LVAL_CONST_STR;
ret->lval.ptr = expbuf - strlen(token);
return ret;
break;
}
}
} else {
basic_errno = BASIC_ERR_SYNTAX_GENERAL;
return NULL;
}
}
return ret;
}
int basic_run_line_v2(char *codeline, int repl_mode)
{
char *buffptr;
@@ -484,52 +255,6 @@ int basic_run_line_v2(char *codeline, int repl_mode)
return 0;
}
int basic_run_line(char *codeline, int repl_mode)
{
/*
* If we are running in repl mode we look for line numbers, THEN we check for immediate mode commands
* If not in repl mode we just check for immediate mode
* Then we give up
*/
basic_expr *expr = NULL;
basic_variable result;
memset(&result, 0x00, sizeof(basic_variable));
if ( repl_mode == 1 ) {
expr = basic_parse_expr(codeline, 1);
if ( basic_errno == BASIC_ERR_SYNTAX_NO_LINE_NUMBER ) {
basic_errno = 0;
_cputs("No line number, parsing with require_line_numbers=0\n");
expr = basic_parse_expr(codeline, 0);
}
} else {
expr = basic_parse_expr(codeline, 0);
}
if ( expr == NULL ) {
basic_report_error("Parsing error: ");
return 1;
}
if ( expr->lval_type == BASIC_LVAL_CMDPTR ) {
if ( expr->lval.cmd_ptr == NULL ) {
basic_errno = BASIC_ERR_INTERNAL_NULLPOINTER;
basic_report_error("Solving error: ");
return 1;
} else {
(*expr->lval.cmd_ptr)(expr->rval.ptr);
if ( basic_errno != 0 ) {
basic_report_error("Command error: ");
return 1;
}
}
} else {
if ( basic_solve_expr(expr, &result) != 1 || basic_errno != 0 ) {
basic_report_error("Solving error: ");
return 1;
}
}
return 0;
}
/***************************************************************
*
* Basic REPL
@@ -571,10 +296,10 @@ void basic_repl(void)
_cputs("READY\n");
basic_repl_mode = 1;
/*basic_memory_line_store("LIST", 10);
basic_memory_line_store("LIST", 10);
basic_memory_line_store("PRINT HELLO\n", 20);
basic_memory_line_store("PRINT WORLD\n", 30);
basic_memory_line_store("PRINT GOODBYE\n", 40);*/
basic_memory_line_store("PRINT GOODBYE\n", 40);
while ( 1 ) {
basic_errno = 0;