Andrew Kesterson
48f650c3af
A program with TRAP set and a line that would not parse printed nothing at all and exited zero. No error line, because akbasic_runtime_error() intercepts for the trap and deliberately prints nothing; and no handler, because the parse branch of process_line_run() then set run_finished_mode regardless -- QUIT for a file -- so the next line boundary the handler would have been entered at never came. Arming an error handler made errors disappear. The guard is to set the finished mode only when the error was actually reported. The runtime path was always right: report_and_reraise() never touched the mode. The same branch also never recorded the status, so the handler that now runs was handed ER# 0. It sets lasterrorstatus from the context the way report_and_reraise() does, and a trapped SCALE with no arguments reports 512. Found while writing the error-code appendix -- documenting what ER# can hold means provoking each code, and this is what happened on the way. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
1394 lines
50 KiB
C
1394 lines
50 KiB
C
/**
|
|
* @file runtime.c
|
|
* @brief Implements the interpreter core: pools, evaluation and the step loop.
|
|
*/
|
|
|
|
#include <ctype.h>
|
|
#include <inttypes.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <strings.h>
|
|
|
|
#include <akerror.h>
|
|
|
|
#include <akbasic/error.h>
|
|
#include <akbasic/parser.h>
|
|
#include <akbasic/runtime.h>
|
|
#include <akbasic/scanner.h>
|
|
#include <akbasic/verbs.h>
|
|
|
|
/* ------------------------------------------------------------------ pools -- */
|
|
|
|
akerr_ErrorContext *akbasic_runtime_new_variable(akbasic_Runtime *obj, akbasic_Variable **dest)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
int i = 0;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL && dest != NULL), AKERR_NULLPOINTER,
|
|
"NULL argument in new_variable");
|
|
for ( i = 0; i < AKBASIC_MAX_VARIABLES; i++ ) {
|
|
if ( !obj->variables[i].used ) {
|
|
memset(&obj->variables[i], 0, sizeof(obj->variables[i]));
|
|
obj->variables[i].used = true;
|
|
*dest = &obj->variables[i];
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
}
|
|
FAIL_RETURN(errctx, AKBASIC_ERR_BOUNDS, "Maximum runtime variables reached");
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_global(akbasic_Runtime *obj, const char *name, akbasic_Variable **dest)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
akbasic_Environment *root = NULL;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL && name != NULL && dest != NULL), AKERR_NULLPOINTER,
|
|
"NULL argument in runtime global");
|
|
FAIL_ZERO_RETURN(errctx, (obj->environment != NULL), AKERR_NULLPOINTER,
|
|
"Runtime has no environment; call akbasic_runtime_init() first");
|
|
|
|
/*
|
|
* Walk to the root rather than using obj->environment. That is the whole
|
|
* point: a script suspended part-way through a bounded run() is usually
|
|
* inside a FOR or GOSUB body, and a variable created there dies when the
|
|
* body pops -- silently, with the script reading it correctly right up
|
|
* until it stops. See the note on the declaration.
|
|
*/
|
|
for ( root = obj->environment; root->parent != NULL; root = root->parent ) {
|
|
}
|
|
PASS(errctx, akbasic_environment_create(root, name, dest));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_new_function(akbasic_Runtime *obj, akbasic_FunctionDef **dest)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
int i = 0;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL && dest != NULL), AKERR_NULLPOINTER,
|
|
"NULL argument in new_function");
|
|
for ( i = 0; i < AKBASIC_MAX_FUNCTIONS; i++ ) {
|
|
if ( !obj->functions[i].used ) {
|
|
memset(&obj->functions[i], 0, sizeof(obj->functions[i]));
|
|
obj->functions[i].used = true;
|
|
obj->functions[i].leafpool.next = 0;
|
|
obj->functions[i].leafpool.capacity = AKBASIC_MAX_LEAVES * 2;
|
|
obj->functions[i].leafpool.leaves = obj->functions[i].leafstorage;
|
|
*dest = &obj->functions[i];
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
}
|
|
FAIL_RETURN(errctx, AKBASIC_ERR_BOUNDS, "Maximum function definitions reached");
|
|
}
|
|
|
|
static akerr_ErrorContext *env_acquire(akbasic_Runtime *obj, akbasic_Environment **dest)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
int i = 0;
|
|
|
|
for ( i = 0; i < AKBASIC_MAX_ENVIRONMENTS; i++ ) {
|
|
if ( !obj->environments[i].used ) {
|
|
obj->environments[i].used = true;
|
|
*dest = &obj->environments[i];
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
}
|
|
FAIL_RETURN(errctx, AKBASIC_ERR_ENVIRONMENT,
|
|
"Environment pool exhausted at line %" PRId64 " (%d in use)",
|
|
(obj->environment == NULL ? 0 : obj->environment->lineno),
|
|
AKBASIC_MAX_ENVIRONMENTS);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_new_environment(akbasic_Runtime *obj)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
akbasic_Environment *env = NULL;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in new_environment");
|
|
PASS(errctx, env_acquire(obj, &env));
|
|
PASS(errctx, akbasic_environment_init(env, obj, obj->environment));
|
|
obj->environment = env;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_prev_environment(akbasic_Runtime *obj)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
akbasic_Environment *popped = NULL;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in prev_environment");
|
|
FAIL_ZERO_RETURN(errctx, (obj->environment->parent != NULL), AKBASIC_ERR_ENVIRONMENT,
|
|
"No previous environment to return to");
|
|
popped = obj->environment;
|
|
obj->environment = popped->parent;
|
|
/*
|
|
* Release it. The reference never does, which is a leak the GC papers over;
|
|
* here the pool is finite, so an unreleased environment is a bug that shows
|
|
* up as exhaustion a few thousand GOSUBs later.
|
|
*/
|
|
popped->used = false;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/* ------------------------------------------------------------- lifecycle -- */
|
|
|
|
akerr_ErrorContext *akbasic_runtime_zero(akbasic_Runtime *obj)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in zero");
|
|
PASS(errctx, akbasic_environment_zero(obj->environment));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_init(akbasic_Runtime *obj, akbasic_TextSink *sink)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in init");
|
|
FAIL_ZERO_RETURN(errctx, (sink != NULL), AKERR_NULLPOINTER, "NULL text sink in init");
|
|
|
|
/*
|
|
* Claim the status band before anything can raise one of our codes, or the
|
|
* first error out of this function prints "Unknown Error". Idempotent, so a
|
|
* host that already called it loses nothing.
|
|
*/
|
|
PASS(errctx, akbasic_error_register());
|
|
|
|
memset(obj, 0, sizeof(*obj));
|
|
obj->sink = sink;
|
|
obj->environment = NULL;
|
|
obj->autoLineNumber = 0;
|
|
obj->eval_clone_identifiers = true;
|
|
obj->errclass = AKBASIC_ERRCLASS_NONE;
|
|
obj->mode = AKBASIC_MODE_REPL;
|
|
obj->run_finished_mode = AKBASIC_MODE_REPL;
|
|
obj->inputEof = false;
|
|
|
|
PASS(errctx, akbasic_graphics_state_init(&obj->gfx));
|
|
PASS(errctx, akbasic_sprite_state_init(&obj->sprite_state));
|
|
PASS(errctx, akbasic_format_state_init(&obj->format_state));
|
|
PASS(errctx, akbasic_console_state_init(&obj->console_state));
|
|
PASS(errctx, akbasic_data_state_init(&obj->data_state));
|
|
PASS(errctx, akbasic_disk_state_init(&obj->disk_state));
|
|
PASS(errctx, akbasic_audio_state_init(&obj->audio_state));
|
|
PASS(errctx, akbasic_valuepool_init(&obj->valuepool));
|
|
PASS(errctx, akbasic_value_zero(&obj->staticTrueValue));
|
|
PASS(errctx, akbasic_value_zero(&obj->staticFalseValue));
|
|
PASS(errctx, akbasic_value_set_bool(&obj->staticTrueValue, true));
|
|
PASS(errctx, akbasic_value_set_bool(&obj->staticFalseValue, false));
|
|
|
|
PASS(errctx, akbasic_runtime_new_environment(obj));
|
|
PASS(errctx, akbasic_runtime_zero(obj));
|
|
PASS(errctx, akbasic_scanner_zero(obj));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_set_devices(akbasic_Runtime *obj, akbasic_GraphicsBackend *graphics, akbasic_AudioBackend *audio, akbasic_InputBackend *input, akbasic_SpriteBackend *sprites)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER,
|
|
"NULL runtime in set_devices");
|
|
|
|
/*
|
|
* No validation of the records themselves. A backend with a NULL entry point
|
|
* is caught at the call site by the verb that needs it, which can say which
|
|
* verb wanted what -- checking every pointer here would only be able to say
|
|
* that something, somewhere, was incomplete.
|
|
*/
|
|
obj->graphics = graphics;
|
|
obj->audio = audio;
|
|
obj->input = input;
|
|
obj->sprites = sprites;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_set_source_path(akbasic_Runtime *obj, const char *path)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
const char *slash = NULL;
|
|
size_t length = 0;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in set_source_path");
|
|
obj->sourcepath[0] = '\0';
|
|
if ( path == NULL || path[0] == '\0' ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
/*
|
|
* The directory, taken here rather than at the point of use. dirname(3)
|
|
* would do it but it is allowed to modify its argument and two of the three
|
|
* libcs this has to build on disagree about which one they implement.
|
|
*/
|
|
slash = strrchr(path, '/');
|
|
length = (slash == NULL ? 0 : (size_t)(slash - path));
|
|
if ( length == 0 ) {
|
|
/* Either no directory at all, or the root. */
|
|
strncpy(obj->sourcepath, (slash == NULL ? "." : "/"), sizeof(obj->sourcepath) - 1);
|
|
obj->sourcepath[sizeof(obj->sourcepath) - 1] = '\0';
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
FAIL_ZERO_RETURN(errctx, (length < sizeof(obj->sourcepath)), AKBASIC_ERR_BOUNDS,
|
|
"Program path of %zu characters exceeds the %d character limit",
|
|
length, AKBASIC_MAX_LINE_LENGTH - 1);
|
|
memcpy(obj->sourcepath, path, length);
|
|
obj->sourcepath[length] = '\0';
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_settime(akbasic_Runtime *obj, int64_t timems)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER,
|
|
"NULL runtime in settime");
|
|
|
|
/*
|
|
* Deliberately not rejecting a time that moves backwards. A host is free to
|
|
* drive this from a paused, scrubbed or replayed clock, and the only thing
|
|
* that happens is a note holding longer than it asked to.
|
|
*/
|
|
obj->timems = timems;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/* ---------------------------------------------------------------- output -- */
|
|
|
|
akerr_ErrorContext *akbasic_runtime_write(akbasic_Runtime *obj, const char *text)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL && text != NULL), AKERR_NULLPOINTER,
|
|
"NULL argument in write");
|
|
PASS(errctx, obj->sink->write(obj->sink, text));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_println(akbasic_Runtime *obj, const char *text)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL && text != NULL), AKERR_NULLPOINTER,
|
|
"NULL argument in println");
|
|
PASS(errctx, obj->sink->writeln(obj->sink, text));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
static const char *errclass_to_string(akbasic_ErrorClass errclass)
|
|
{
|
|
switch ( errclass ) {
|
|
case AKBASIC_ERRCLASS_IO: return "IO ERROR";
|
|
case AKBASIC_ERRCLASS_PARSE: return "PARSE ERROR";
|
|
case AKBASIC_ERRCLASS_RUNTIME: return "RUNTIME ERROR";
|
|
case AKBASIC_ERRCLASS_SYNTAX: return "SYNTAX ERROR";
|
|
default: return "UNDEF";
|
|
}
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_error(akbasic_Runtime *obj, akbasic_ErrorClass errclass, const char *message)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
char line[AKBASIC_MAX_LINE_LENGTH * 2];
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL && message != NULL), AKERR_NULLPOINTER,
|
|
"NULL argument in runtime error");
|
|
|
|
/*
|
|
* TRAP intercepts here, because this is the one place a BASIC-visible error
|
|
* is reported and the one place the run is stopped. An armed trap turns both
|
|
* off: nothing is printed, `errclass` stays clear so the step loop keeps
|
|
* going, and the handler is entered at the next line boundary by the same
|
|
* machinery COLLISION uses.
|
|
*
|
|
* Not while a handler is already running. An error inside an error handler
|
|
* is reported and stops the program, which is the only way out of a handler
|
|
* that is itself broken -- a C128 does the same.
|
|
*/
|
|
if ( obj->interrupts[AKBASIC_INTERRUPT_ERROR].armed && obj->handlerenv == NULL ) {
|
|
PASS(errctx, akbasic_trap_set_error_variables(obj, obj->lasterrorstatus,
|
|
obj->environment->lineno));
|
|
PASS(errctx, akbasic_runtime_raise_interrupt(obj, AKBASIC_INTERRUPT_ERROR));
|
|
/* The rest of the failing line does not run; the handler does. */
|
|
obj->skiprestofline = true;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
obj->errclass = errclass;
|
|
/* Where HELP will look. Recorded before the message is built, so a report
|
|
* that itself fails still leaves the line behind. */
|
|
obj->errorline = obj->environment->lineno;
|
|
/*
|
|
* The format, the trailing \n inside the string, and the second newline
|
|
* writeln adds are all part of the acceptance contract --
|
|
* tests/language/array_outofbounds.txt ends in 0a 0a. See TODO.md 1.8.
|
|
*/
|
|
snprintf(line, sizeof(line), "? %" PRId64 " : %s %s\n",
|
|
obj->environment->lineno, errclass_to_string(errclass), message);
|
|
PASS(errctx, akbasic_runtime_println(obj, line));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_set_mode(akbasic_Runtime *obj, int mode)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in set_mode");
|
|
obj->mode = mode;
|
|
if ( obj->mode == AKBASIC_MODE_REPL ) {
|
|
PASS(errctx, akbasic_runtime_println(obj, "READY"));
|
|
}
|
|
/*
|
|
* File the program's labels here rather than in any one of the several
|
|
* places that start a run. Every one of them -- akbasic_runtime_start(),
|
|
* RUN, CONT, and the end of a RUNSTREAM load -- arrives through this
|
|
* function, and the last of those is the one a driver reading a file from
|
|
* argv takes, where the program does not exist yet when start() is called.
|
|
*/
|
|
if ( obj->mode == AKBASIC_MODE_RUN && obj->environment != NULL ) {
|
|
PASS(errctx, akbasic_runtime_scan_labels(obj));
|
|
/*
|
|
* And the DATA items, for the same reason and at the same moment: READ
|
|
* walks a cursor along a list built before the program runs, so a DATA
|
|
* line *before* its READ is found -- which it was not when READ skipped
|
|
* forward looking for one.
|
|
*/
|
|
PASS(errctx, akbasic_data_scan(obj));
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/* ------------------------------------------------------------ evaluation -- */
|
|
|
|
/*
|
|
* Report a runtime error carrying an akerr message, then re-raise. Used where
|
|
* the reference calls basicError() and returns the error: the BASIC-visible line
|
|
* goes to the sink and the context keeps propagating.
|
|
*/
|
|
static akerr_ErrorContext *report_and_reraise(akbasic_Runtime *obj, akerr_ErrorContext *cause)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
char message[AKERR_MAX_ERROR_CONTEXT_STRING_LENGTH];
|
|
int status = cause->status;
|
|
|
|
snprintf(message, sizeof(message), "%s", cause->message);
|
|
/* What ER# reports, if a TRAP is armed. Recorded before the context goes. */
|
|
obj->lasterrorstatus = status;
|
|
cause->handled = true;
|
|
IGNORE(akerr_release_error(cause));
|
|
PASS(errctx, akbasic_runtime_error(obj, AKBASIC_ERRCLASS_RUNTIME, message));
|
|
FAIL_RETURN(errctx, status, "%s", message);
|
|
}
|
|
|
|
static akerr_ErrorContext *evaluate_identifier(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value **dest)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
akbasic_ASTLeaf *texpr = NULL;
|
|
akbasic_Value *tval = NULL;
|
|
akbasic_Value *slot = NULL;
|
|
akbasic_Value *copy = NULL;
|
|
akbasic_Variable *variable = NULL;
|
|
int64_t subscripts[AKBASIC_MAX_ARRAY_DEPTH];
|
|
int subscriptcount = 0;
|
|
|
|
/*
|
|
* An identifier's subscript list hangs off .expr, deliberately clear of
|
|
* .right -- which is where an argument list chains its arguments, and where
|
|
* INPUT's parse handler would otherwise collide with it. Checked for the
|
|
* ARRAY_SUBSCRIPT operator anyway, because .expr means something else on the
|
|
* leaf types that use it for grouping.
|
|
*/
|
|
texpr = expr->expr;
|
|
if ( texpr != NULL &&
|
|
texpr->leaftype == AKBASIC_LEAF_ARGUMENTLIST &&
|
|
texpr->operator_ == AKBASIC_TOK_ARRAY_SUBSCRIPT ) {
|
|
for ( texpr = texpr->right; texpr != NULL; texpr = texpr->next ) {
|
|
FAIL_ZERO_RETURN(errctx, (subscriptcount < AKBASIC_MAX_ARRAY_DEPTH),
|
|
AKBASIC_ERR_BOUNDS,
|
|
"More than %d array subscripts", AKBASIC_MAX_ARRAY_DEPTH);
|
|
PASS(errctx, akbasic_runtime_evaluate(obj, texpr, &tval));
|
|
FAIL_NONZERO_RETURN(errctx, (tval->valuetype != AKBASIC_TYPE_INTEGER),
|
|
AKBASIC_ERR_TYPE,
|
|
"Array dimensions must evaluate to integer (C)");
|
|
subscripts[subscriptcount] = tval->intval;
|
|
subscriptcount += 1;
|
|
}
|
|
}
|
|
if ( subscriptcount == 0 ) {
|
|
subscripts[0] = 0;
|
|
subscriptcount = 1;
|
|
}
|
|
|
|
PASS(errctx, akbasic_environment_get(obj->environment, expr->identifier, &variable));
|
|
FAIL_ZERO_RETURN(errctx, (variable != NULL), AKBASIC_ERR_UNDEFINED,
|
|
"Identifier %s is undefined", expr->identifier);
|
|
PASS(errctx, akbasic_variable_get_subscript(variable, subscripts, subscriptcount, &slot));
|
|
|
|
if ( !obj->eval_clone_identifiers ) {
|
|
*dest = slot;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
PASS(errctx, akbasic_environment_new_value(obj->environment, ©));
|
|
PASS(errctx, akbasic_value_clone(slot, copy));
|
|
*dest = copy;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
static akerr_ErrorContext *evaluate_binary(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value **dest)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
akbasic_Value *lval = NULL;
|
|
akbasic_Value *rval = NULL;
|
|
akbasic_Value *scratch = NULL;
|
|
|
|
PASS(errctx, akbasic_runtime_evaluate(obj, expr->left, &lval));
|
|
PASS(errctx, akbasic_runtime_evaluate(obj, expr->right, &rval));
|
|
|
|
if ( expr->operator_ == AKBASIC_TOK_ASSIGNMENT ) {
|
|
PASS(errctx, akbasic_environment_assign(obj->environment, expr->left, rval, dest));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
PASS(errctx, akbasic_environment_new_value(obj->environment, &scratch));
|
|
switch ( expr->operator_ ) {
|
|
case AKBASIC_TOK_MINUS:
|
|
PASS(errctx, akbasic_value_math_minus(lval, rval, scratch, dest));
|
|
break;
|
|
case AKBASIC_TOK_PLUS:
|
|
PASS(errctx, akbasic_value_math_plus(lval, rval, scratch, dest));
|
|
break;
|
|
case AKBASIC_TOK_LEFT_SLASH:
|
|
PASS(errctx, akbasic_value_math_divide(lval, rval, scratch, dest));
|
|
break;
|
|
case AKBASIC_TOK_STAR:
|
|
PASS(errctx, akbasic_value_math_multiply(lval, rval, scratch, dest));
|
|
break;
|
|
case AKBASIC_TOK_AND:
|
|
PASS(errctx, akbasic_value_bitwise_and(lval, rval, scratch, dest));
|
|
break;
|
|
case AKBASIC_TOK_OR:
|
|
PASS(errctx, akbasic_value_bitwise_or(lval, rval, scratch, dest));
|
|
break;
|
|
case AKBASIC_TOK_LESS_THAN:
|
|
PASS(errctx, akbasic_value_less_than(lval, rval, scratch, dest));
|
|
break;
|
|
case AKBASIC_TOK_LESS_THAN_EQUAL:
|
|
PASS(errctx, akbasic_value_less_than_equal(lval, rval, scratch, dest));
|
|
break;
|
|
case AKBASIC_TOK_EQUAL:
|
|
PASS(errctx, akbasic_value_is_equal(lval, rval, scratch, dest));
|
|
break;
|
|
case AKBASIC_TOK_NOT_EQUAL:
|
|
PASS(errctx, akbasic_value_is_not_equal(lval, rval, scratch, dest));
|
|
break;
|
|
case AKBASIC_TOK_GREATER_THAN:
|
|
PASS(errctx, akbasic_value_greater_than(lval, rval, scratch, dest));
|
|
break;
|
|
case AKBASIC_TOK_GREATER_THAN_EQUAL:
|
|
PASS(errctx, akbasic_value_greater_than_equal(lval, rval, scratch, dest));
|
|
break;
|
|
default:
|
|
FAIL_RETURN(errctx, AKBASIC_ERR_SYNTAX,
|
|
"Don't know how to perform binary operation %d", (int)expr->operator_);
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_evaluate(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value **dest)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
akbasic_Value *lval = NULL;
|
|
akbasic_Value *rval = NULL;
|
|
akbasic_Value *scratch = NULL;
|
|
const akbasic_Verb *verb = NULL;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL && dest != NULL), AKERR_NULLPOINTER,
|
|
"NULL argument in evaluate");
|
|
FAIL_ZERO_RETURN(errctx, (expr != NULL), AKERR_NULLPOINTER, "NULL expression in evaluate");
|
|
|
|
PASS(errctx, akbasic_environment_new_value(obj->environment, &lval));
|
|
PASS(errctx, akbasic_value_zero(lval));
|
|
*dest = lval;
|
|
|
|
switch ( expr->leaftype ) {
|
|
case AKBASIC_LEAF_GROUPING:
|
|
PASS(errctx, akbasic_runtime_evaluate(obj, expr->expr, dest));
|
|
SUCCEED_RETURN(errctx);
|
|
|
|
case AKBASIC_LEAF_BRANCH:
|
|
ATTEMPT {
|
|
CATCH(errctx, akbasic_runtime_evaluate(obj, expr->expr, &rval));
|
|
} CLEANUP {
|
|
} PROCESS(errctx) {
|
|
} HANDLE_DEFAULT(errctx) {
|
|
PASS(errctx, report_and_reraise(obj, errctx));
|
|
} FINISH(errctx, true);
|
|
/*
|
|
* Who owns the rest of the line?
|
|
*
|
|
* BASIC 7.0 scopes every statement after THEN to the condition, and the
|
|
* parser only ever takes *one* statement for each arm -- the rest arrive
|
|
* at the statement loop as ordinary top-level statements. So the branch
|
|
* has to say whether that loop should run them.
|
|
*
|
|
* IF C THEN A : B C false -> B belongs to THEN, skip it
|
|
* IF C THEN A ELSE B : D C true -> D belongs to ELSE, skip it
|
|
*
|
|
* which is not "skip when false": the remainder always belongs to
|
|
* whichever arm was written last, so it is skipped exactly when that arm
|
|
* is the one *not* taken. With an ELSE present the last arm is ELSE;
|
|
* without one it is THEN.
|
|
*/
|
|
{
|
|
bool taken = akbasic_value_is_truthy(rval);
|
|
akbasic_ASTLeaf *notaken = (taken ? expr->right : expr->left);
|
|
|
|
obj->skiprestofline = ((expr->right != NULL) == taken);
|
|
/*
|
|
* `IF c THEN BEGIN ... BEND` is a block, and the arm not taken has to
|
|
* skip the *lines* between here and its BEND -- skiprestofline only
|
|
* reaches the end of this line. Arming the wait is what makes a
|
|
* multi-line IF possible at all; BEND clears it.
|
|
*/
|
|
if ( notaken != NULL && notaken->leaftype == AKBASIC_LEAF_COMMAND &&
|
|
strcmp(notaken->identifier, "BEGIN") == 0 ) {
|
|
PASS(errctx, akbasic_environment_wait_for_command(obj->environment, "BEND"));
|
|
}
|
|
if ( taken ) {
|
|
PASS(errctx, akbasic_runtime_evaluate(obj, expr->left, dest));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
if ( expr->right != NULL ) {
|
|
/* A false branch is optional for some branching operations. */
|
|
PASS(errctx, akbasic_runtime_evaluate(obj, expr->right, dest));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
|
|
case AKBASIC_LEAF_IDENTIFIER_INT:
|
|
case AKBASIC_LEAF_IDENTIFIER_FLOAT:
|
|
case AKBASIC_LEAF_IDENTIFIER_STRING:
|
|
PASS(errctx, evaluate_identifier(obj, expr, dest));
|
|
SUCCEED_RETURN(errctx);
|
|
|
|
case AKBASIC_LEAF_IDENTIFIER:
|
|
/* A bare identifier with no type suffix is a label. */
|
|
lval->valuetype = AKBASIC_TYPE_INTEGER;
|
|
PASS(errctx, akbasic_environment_get_label(obj->environment, expr->identifier, &lval->intval));
|
|
SUCCEED_RETURN(errctx);
|
|
|
|
case AKBASIC_LEAF_LITERAL_INT:
|
|
lval->valuetype = AKBASIC_TYPE_INTEGER;
|
|
lval->intval = expr->literal_int;
|
|
SUCCEED_RETURN(errctx);
|
|
|
|
case AKBASIC_LEAF_LITERAL_FLOAT:
|
|
lval->valuetype = AKBASIC_TYPE_FLOAT;
|
|
lval->floatval = expr->literal_float;
|
|
SUCCEED_RETURN(errctx);
|
|
|
|
case AKBASIC_LEAF_LITERAL_STRING:
|
|
lval->valuetype = AKBASIC_TYPE_STRING;
|
|
memcpy(lval->stringval, expr->literal_string, sizeof(lval->stringval));
|
|
SUCCEED_RETURN(errctx);
|
|
|
|
case AKBASIC_LEAF_UNARY:
|
|
/* .left: a unary leaf's operand, kept clear of the argument chain. */
|
|
PASS(errctx, akbasic_runtime_evaluate(obj, expr->left, &rval));
|
|
PASS(errctx, akbasic_environment_new_value(obj->environment, &scratch));
|
|
if ( expr->operator_ == AKBASIC_TOK_MINUS ) {
|
|
PASS(errctx, akbasic_value_invert(rval, scratch, dest));
|
|
} else if ( expr->operator_ == AKBASIC_TOK_NOT ) {
|
|
PASS(errctx, akbasic_value_bitwise_not(rval, scratch, dest));
|
|
} else {
|
|
FAIL_RETURN(errctx, AKBASIC_ERR_SYNTAX,
|
|
"Don't know how to perform operation %d on unary type %d",
|
|
(int)expr->operator_, (int)rval->valuetype);
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
|
|
case AKBASIC_LEAF_FUNCTION:
|
|
PASS(errctx, akbasic_verb_lookup(expr->identifier, &verb));
|
|
if ( verb != NULL && verb->exec != NULL && verb->tokentype == AKBASIC_TOK_FUNCTION ) {
|
|
PASS(errctx, verb->exec(obj, expr, lval, rval, dest));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
PASS(errctx, akbasic_runtime_user_function(obj, expr, dest));
|
|
SUCCEED_RETURN(errctx);
|
|
|
|
case AKBASIC_LEAF_COMMAND_IMMEDIATE:
|
|
case AKBASIC_LEAF_COMMAND:
|
|
PASS(errctx, akbasic_verb_lookup(expr->identifier, &verb));
|
|
FAIL_ZERO_RETURN(errctx, (verb != NULL && verb->exec != NULL), AKBASIC_ERR_UNDEFINED,
|
|
"Unknown command %s", expr->identifier);
|
|
PASS(errctx, verb->exec(obj, expr, lval, rval, dest));
|
|
SUCCEED_RETURN(errctx);
|
|
|
|
case AKBASIC_LEAF_BINARY:
|
|
PASS(errctx, evaluate_binary(obj, expr, dest));
|
|
SUCCEED_RETURN(errctx);
|
|
|
|
default:
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_interpret(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value **dest)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL && expr != NULL && dest != NULL), AKERR_NULLPOINTER,
|
|
"NULL argument in interpret");
|
|
/*
|
|
* While an environment is skipping forward to a verb, nothing runs but that
|
|
* verb. This is what keeps a zero-iteration FOR body from executing, given
|
|
* that the loop condition is evaluated at the bottom of the structure.
|
|
*/
|
|
if ( akbasic_environment_is_waiting_for_any(obj->environment) ) {
|
|
if ( expr->leaftype != AKBASIC_LEAF_COMMAND ||
|
|
!akbasic_environment_is_waiting_for(obj->environment, expr->identifier) ) {
|
|
*dest = &obj->staticTrueValue;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
}
|
|
ATTEMPT {
|
|
CATCH(errctx, akbasic_runtime_evaluate(obj, expr, dest));
|
|
} CLEANUP {
|
|
} PROCESS(errctx) {
|
|
} HANDLE_DEFAULT(errctx) {
|
|
PASS(errctx, report_and_reraise(obj, errctx));
|
|
} FINISH(errctx, true);
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_interpret_immediate(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value **dest)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL && expr != NULL && dest != NULL), AKERR_NULLPOINTER,
|
|
"NULL argument in interpret_immediate");
|
|
*dest = NULL;
|
|
if ( expr->leaftype != AKBASIC_LEAF_COMMAND_IMMEDIATE ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
PASS(errctx, akbasic_runtime_evaluate(obj, expr, dest));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_user_function(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value **dest)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
akbasic_FunctionDef *fndef = NULL;
|
|
akbasic_Environment *targetenv = obj->environment;
|
|
akbasic_ASTLeaf *leafptr = NULL;
|
|
akbasic_ASTLeaf *argptr = NULL;
|
|
akbasic_Value *argvalue = NULL;
|
|
akbasic_Value *unused = NULL;
|
|
void *fnptr = NULL;
|
|
|
|
PASS(errctx, akbasic_environment_get_function(obj->environment, expr->identifier, &fnptr));
|
|
fndef = (akbasic_FunctionDef *)fnptr;
|
|
|
|
/*
|
|
* The function's environment is owned by the funcdef, not by the pool free
|
|
* list: it is reset on every call and outlives any single one. The reference
|
|
* holds it by value inside BasicFunctionDef for the same reason.
|
|
*/
|
|
if ( fndef->environment == NULL ) {
|
|
PASS(errctx, akbasic_runtime_new_environment(obj));
|
|
fndef->environment = obj->environment;
|
|
obj->environment = targetenv;
|
|
}
|
|
PASS(errctx, akbasic_environment_init(fndef->environment, obj, obj->environment));
|
|
|
|
/* Bind arguments into the function's scope before entering it. */
|
|
leafptr = (expr->right != NULL ? expr->right->right : NULL);
|
|
argptr = (fndef->arglist != NULL ? fndef->arglist->right : NULL);
|
|
while ( leafptr != NULL && argptr != NULL ) {
|
|
akbasic_Environment *callerenv = obj->environment;
|
|
PASS(errctx, akbasic_runtime_evaluate(obj, leafptr, &argvalue));
|
|
obj->environment = fndef->environment;
|
|
PASS(errctx, akbasic_environment_assign(fndef->environment, argptr, argvalue, &unused));
|
|
obj->environment = callerenv;
|
|
leafptr = leafptr->next;
|
|
argptr = argptr->next;
|
|
}
|
|
|
|
obj->environment = fndef->environment;
|
|
|
|
if ( fndef->expression != NULL ) {
|
|
PASS(errctx, akbasic_runtime_evaluate(obj, fndef->expression, dest));
|
|
obj->environment = obj->environment->parent;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/*
|
|
* A multi-line subroutine. Hand control to its environment and let the
|
|
* caller's step loop run it until RETURN pops back out. The result is the
|
|
* value RETURN parked in the child environment.
|
|
*/
|
|
obj->environment->gosubReturnLine = obj->environment->lineno + 1;
|
|
obj->environment->nextline = fndef->lineno;
|
|
while ( obj->environment != targetenv && obj->mode == AKBASIC_MODE_RUN ) {
|
|
PASS(errctx, akbasic_runtime_process_line_run(obj));
|
|
}
|
|
*dest = &fndef->environment->returnValue;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/* ------------------------------------------------------------ line cycle -- */
|
|
|
|
int64_t akbasic_runtime_find_previous_lineno(akbasic_Runtime *obj)
|
|
{
|
|
int64_t i = 0;
|
|
|
|
for ( i = obj->environment->lineno - 1; i > 0; i-- ) {
|
|
if ( obj->source[i].code[0] != '\0' ) {
|
|
return i;
|
|
}
|
|
}
|
|
return obj->environment->lineno;
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_store_line(akbasic_Runtime *obj, int64_t lineno, const char *code)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (lineno >= 0 && lineno < AKBASIC_MAX_SOURCE_LINES),
|
|
AKBASIC_ERR_BOUNDS,
|
|
"Line number %" PRId64 " is outside 0..%d",
|
|
lineno, AKBASIC_MAX_SOURCE_LINES - 1);
|
|
FAIL_ZERO_RETURN(errctx, (strlen(code) < AKBASIC_MAX_LINE_LENGTH), AKBASIC_ERR_BOUNDS,
|
|
"Source line exceeds the %d character limit", AKBASIC_MAX_LINE_LENGTH - 1);
|
|
strncpy(obj->source[lineno].code, code, AKBASIC_MAX_LINE_LENGTH - 1);
|
|
obj->source[lineno].code[AKBASIC_MAX_LINE_LENGTH - 1] = '\0';
|
|
obj->source[lineno].lineno = lineno;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_process_line_runstream(akbasic_Runtime *obj)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
char buffer[AKBASIC_MAX_LINE_LENGTH];
|
|
char scanned[AKBASIC_MAX_LINE_LENGTH];
|
|
bool eof = false;
|
|
|
|
PASS(errctx, obj->sink->readline(obj->sink, buffer, sizeof(buffer), &eof));
|
|
if ( eof ) {
|
|
obj->environment->nextline = 0;
|
|
PASS(errctx, akbasic_runtime_set_mode(obj, AKBASIC_MODE_RUN));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/*
|
|
* All this mode does is pick the line number off the front and file the
|
|
* source line under it. DLOAD reaches this from REPL mode, where the line
|
|
* numbers must be stripped the same way the REPL strips them.
|
|
*/
|
|
PASS(errctx, akbasic_scanner_scan(obj, buffer, scanned, sizeof(scanned)));
|
|
if ( obj->mode == AKBASIC_MODE_REPL ) {
|
|
PASS(errctx, akbasic_runtime_store_line(obj, obj->environment->lineno, scanned));
|
|
} else {
|
|
PASS(errctx, akbasic_runtime_store_line(obj, obj->environment->lineno, buffer));
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_process_line_repl(akbasic_Runtime *obj)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
char prompt[32];
|
|
char scanned[AKBASIC_MAX_LINE_LENGTH];
|
|
akbasic_ASTLeaf *leaf = NULL;
|
|
akbasic_Value *value = NULL;
|
|
akbasic_Parser parser;
|
|
bool eof = false;
|
|
|
|
if ( obj->autoLineNumber > 0 ) {
|
|
snprintf(prompt, sizeof(prompt), "%" PRId64 " ",
|
|
obj->environment->lineno + obj->autoLineNumber);
|
|
PASS(errctx, akbasic_runtime_write(obj, prompt));
|
|
}
|
|
|
|
PASS(errctx, obj->sink->readline(obj->sink, obj->userline, sizeof(obj->userline), &eof));
|
|
if ( eof ) {
|
|
obj->inputEof = true;
|
|
PASS(errctx, akbasic_runtime_set_mode(obj, AKBASIC_MODE_QUIT));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
if ( obj->userline[0] == '\0' ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
obj->environment->lineno += obj->autoLineNumber;
|
|
obj->hadlinenumber = false;
|
|
PASS(errctx, akbasic_scanner_scan(obj, obj->userline, scanned, sizeof(scanned)));
|
|
PASS(errctx, akbasic_parser_init(&parser, obj));
|
|
obj->skiprestofline = false;
|
|
|
|
while ( !akbasic_parser_is_at_end(&parser) && !obj->skiprestofline ) {
|
|
ATTEMPT {
|
|
CATCH(errctx, akbasic_parser_parse(&parser, &leaf));
|
|
} CLEANUP {
|
|
} PROCESS(errctx) {
|
|
} HANDLE_DEFAULT(errctx) {
|
|
char message[AKERR_MAX_ERROR_CONTEXT_STRING_LENGTH];
|
|
snprintf(message, sizeof(message), "%s", errctx->message);
|
|
obj->lasterrorstatus = errctx->status;
|
|
IGNORE(akbasic_runtime_error(obj, AKBASIC_ERRCLASS_PARSE, message));
|
|
} FINISH(errctx, false);
|
|
if ( obj->errclass != AKBASIC_ERRCLASS_NONE ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
if ( leaf == NULL ) {
|
|
/* Nothing but statement separators left; an empty statement is not one. */
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* A line typed with a number is program text; a line typed without one is
|
|
* a statement to run now. That is direct mode, and it is what makes
|
|
* `PRINT 2 + 2` at the prompt answer `4` instead of quietly becoming
|
|
* line 0 of a program.
|
|
*
|
|
* The reference only ever ran the verbs it marked immediate -- RUN, LIST,
|
|
* NEW and the rest -- and filed everything else, so most of the language
|
|
* was unreachable from a prompt.
|
|
*/
|
|
if ( !obj->hadlinenumber ) {
|
|
/*
|
|
* Swallow the context exactly as process_line_run() does, and for the
|
|
* same reason: interpret() has already put the BASIC-visible line on
|
|
* the sink, and letting the error out of here hands a *script's*
|
|
* mistake to the host. A bare PASS here meant `VERIFY` against a file
|
|
* that did not match -- an ordinary user answer -- terminated the
|
|
* driver with a stack trace instead of printing an error line.
|
|
*/
|
|
ATTEMPT {
|
|
CATCH(errctx, akbasic_runtime_interpret(obj, leaf, &value));
|
|
} CLEANUP {
|
|
} PROCESS(errctx) {
|
|
} HANDLE_DEFAULT(errctx) {
|
|
} FINISH(errctx, false);
|
|
if ( obj->errclass != AKBASIC_ERRCLASS_NONE ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
continue;
|
|
}
|
|
PASS(errctx, akbasic_runtime_interpret_immediate(obj, leaf, &value));
|
|
if ( value == NULL ) {
|
|
/* Not an immediate command, so it is program text: file it. */
|
|
PASS(errctx, akbasic_runtime_store_line(obj, obj->environment->lineno, scanned));
|
|
} else if ( obj->autoLineNumber > 0 ) {
|
|
obj->environment->lineno = akbasic_runtime_find_previous_lineno(obj);
|
|
}
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_process_line_run(akbasic_Runtime *obj)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
char line[AKBASIC_MAX_LINE_LENGTH];
|
|
akbasic_ASTLeaf *leaf = NULL;
|
|
akbasic_Value *value = NULL;
|
|
akbasic_Parser parser;
|
|
|
|
if ( obj->environment->nextline >= AKBASIC_MAX_SOURCE_LINES ) {
|
|
PASS(errctx, akbasic_runtime_set_mode(obj, obj->run_finished_mode));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
strncpy(line, obj->source[obj->environment->nextline].code, sizeof(line) - 1);
|
|
line[sizeof(line) - 1] = '\0';
|
|
obj->environment->lineno = obj->environment->nextline;
|
|
obj->environment->nextline += 1;
|
|
if ( line[0] == '\0' ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/*
|
|
* TRON. Inline and with no newline, which is what a C128 prints: a traced
|
|
* program's output reads `[10][20]HELLO`. Blank lines are skipped above, so
|
|
* a trace shows only the lines that actually hold something.
|
|
*/
|
|
if ( obj->trace ) {
|
|
char tracemark[32];
|
|
snprintf(tracemark, sizeof(tracemark), "[%" PRId64 "]", obj->environment->lineno);
|
|
PASS(errctx, akbasic_runtime_write(obj, tracemark));
|
|
}
|
|
|
|
PASS(errctx, akbasic_scanner_scan(obj, line, NULL, 0));
|
|
PASS(errctx, akbasic_parser_init(&parser, obj));
|
|
obj->skiprestofline = false;
|
|
|
|
while ( !akbasic_parser_is_at_end(&parser) && !obj->skiprestofline ) {
|
|
ATTEMPT {
|
|
CATCH(errctx, akbasic_parser_parse(&parser, &leaf));
|
|
} CLEANUP {
|
|
} PROCESS(errctx) {
|
|
} HANDLE_DEFAULT(errctx) {
|
|
char message[AKERR_MAX_ERROR_CONTEXT_STRING_LENGTH];
|
|
snprintf(message, sizeof(message), "%s", errctx->message);
|
|
/*
|
|
* What ER# reports, recorded before the context goes -- the same line
|
|
* report_and_reraise() carries for a runtime error, and it was missing
|
|
* here, so a trapped parse error handed the handler ER# 0.
|
|
*/
|
|
obj->lasterrorstatus = errctx->status;
|
|
IGNORE(akbasic_runtime_error(obj, AKBASIC_ERRCLASS_PARSE, message));
|
|
/*
|
|
* Only when the error was actually reported. An armed TRAP intercepts
|
|
* inside akbasic_runtime_error() and leaves `errclass` clear, meaning
|
|
* "the handler runs at the next line boundary" -- and ending the run
|
|
* here reaches that boundary never. Setting the mode unconditionally
|
|
* made a parse error under a TRAP vanish outright: no error line,
|
|
* because the trap suppressed it, and no handler, because
|
|
* run_finished_mode for a file is QUIT. Arming an error handler made
|
|
* errors disappear, which is the opposite of what it is for.
|
|
*/
|
|
if ( obj->errclass != AKBASIC_ERRCLASS_NONE ) {
|
|
IGNORE(akbasic_runtime_set_mode(obj, obj->run_finished_mode));
|
|
}
|
|
} FINISH(errctx, false);
|
|
if ( obj->errclass != AKBASIC_ERRCLASS_NONE ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
if ( leaf == NULL ) {
|
|
/* Nothing but statement separators left; an empty statement is not one. */
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* The reference discards both results here. An error has already been
|
|
* reported to the sink by interpret(); swallowing the context keeps a
|
|
* BASIC-level error from tearing down the host, which is the whole point
|
|
* of goal 3.
|
|
*/
|
|
ATTEMPT {
|
|
CATCH(errctx, akbasic_runtime_interpret(obj, leaf, &value));
|
|
} CLEANUP {
|
|
} PROCESS(errctx) {
|
|
} HANDLE_DEFAULT(errctx) {
|
|
} FINISH(errctx, false);
|
|
if ( obj->errclass != AKBASIC_ERRCLASS_NONE ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/* --------------------------------------------------------- label prescan -- */
|
|
|
|
/**
|
|
* @brief File any `LABEL <name>` this one source line declares.
|
|
*
|
|
* Walks the line a statement at a time, which is all that is needed: `LABEL` is
|
|
* a verb, a verb starts a statement, and statements are separated by `:`. The
|
|
* only thing that can hide a colon is a string literal, so that is the only
|
|
* thing this has to understand about the rest of the language.
|
|
*
|
|
* @param root The root environment, whose label table this writes.
|
|
* @param code One source line, with or without its line number still on it.
|
|
* @param lineno The number to file any label under.
|
|
* @return `NULL` on success, otherwise an error context owned by the caller.
|
|
* @throws AKBASIC_ERR_BOUNDS When the label table is full.
|
|
*/
|
|
static akerr_ErrorContext *scan_line_labels(akbasic_Environment *root, const char *code, int64_t lineno)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
const char *cursor = code;
|
|
bool statementstart = true;
|
|
bool instring = false;
|
|
|
|
while ( *cursor != '\0' ) {
|
|
if ( instring ) {
|
|
instring = (*cursor != '"');
|
|
cursor += 1;
|
|
continue;
|
|
}
|
|
if ( *cursor == '"' ) {
|
|
instring = true;
|
|
statementstart = false;
|
|
cursor += 1;
|
|
continue;
|
|
}
|
|
if ( *cursor == ':' ) {
|
|
statementstart = true;
|
|
cursor += 1;
|
|
continue;
|
|
}
|
|
if ( isspace((unsigned char)*cursor) ) {
|
|
cursor += 1;
|
|
continue;
|
|
}
|
|
/*
|
|
* A stored line may still carry its own line number. RUNSTREAM files the
|
|
* raw text and lets the scanner strip the number again on the way to
|
|
* execution, where akbasic_runtime_load() files what the scanner already
|
|
* stripped -- so "30 LABEL X" and "LABEL X" are both real spellings of
|
|
* source[30], depending on how the program arrived. Step over the number
|
|
* without ending the statement.
|
|
*/
|
|
if ( statementstart && isdigit((unsigned char)*cursor) ) {
|
|
while ( isdigit((unsigned char)*cursor) ) {
|
|
cursor += 1;
|
|
}
|
|
continue;
|
|
}
|
|
if ( statementstart && strncasecmp(cursor, "LABEL", 5) == 0
|
|
&& !isalnum((unsigned char)cursor[5]) ) {
|
|
char name[AKBASIC_SYMTAB_MAX_KEY];
|
|
size_t used = 0;
|
|
|
|
cursor += 5;
|
|
while ( isspace((unsigned char)*cursor) ) {
|
|
cursor += 1;
|
|
}
|
|
/*
|
|
* Copied as written. Verbs are case-insensitive in this dialect and
|
|
* identifiers are not, so folding the name here would file a label
|
|
* under a spelling `LABEL` itself never uses.
|
|
*/
|
|
while ( isalnum((unsigned char)*cursor) && used < sizeof(name) - 1 ) {
|
|
name[used] = *cursor;
|
|
used += 1;
|
|
cursor += 1;
|
|
}
|
|
name[used] = '\0';
|
|
if ( used > 0 ) {
|
|
PASS(errctx, akbasic_symtab_set(&root->labels, name, NULL, lineno));
|
|
}
|
|
statementstart = false;
|
|
continue;
|
|
}
|
|
statementstart = false;
|
|
cursor += 1;
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_scan_labels(akbasic_Runtime *obj)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
akbasic_Environment *root = NULL;
|
|
int64_t i = 0;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in scan_labels");
|
|
FAIL_ZERO_RETURN(errctx, (obj->environment != NULL), AKERR_NULLPOINTER,
|
|
"Runtime has no environment; call akbasic_runtime_init() first");
|
|
for ( root = obj->environment; root->parent != NULL; root = root->parent ) {
|
|
}
|
|
for ( i = 0; i < AKBASIC_MAX_SOURCE_LINES; i++ ) {
|
|
if ( obj->source[i].code[0] != '\0' ) {
|
|
PASS(errctx, scan_line_labels(root, obj->source[i].code, i));
|
|
}
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/* ------------------------------------------------------------ interrupts -- */
|
|
|
|
akerr_ErrorContext *akbasic_runtime_arm_interrupt(akbasic_Runtime *obj, akbasic_InterruptSource source, int64_t line, const char *label)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
akbasic_Interrupt *slot = NULL;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in arm_interrupt");
|
|
FAIL_ZERO_RETURN(errctx, (source >= 0 && source < AKBASIC_MAX_INTERRUPTS),
|
|
AKBASIC_ERR_BOUNDS, "Interrupt source %d is outside 0..%d",
|
|
(int)source, AKBASIC_MAX_INTERRUPTS - 1);
|
|
FAIL_ZERO_RETURN(errctx, ((line > 0) != (label != NULL && label[0] != '\0')),
|
|
AKBASIC_ERR_VALUE,
|
|
"An interrupt handler is named by a line number or by a label, not both and not neither");
|
|
|
|
slot = &obj->interrupts[source];
|
|
slot->armed = true;
|
|
slot->line = line;
|
|
slot->label[0] = '\0';
|
|
if ( label != NULL && label[0] != '\0' ) {
|
|
FAIL_ZERO_RETURN(errctx, (strlen(label) < sizeof(slot->label)), AKBASIC_ERR_BOUNDS,
|
|
"Handler label \"%s\" exceeds the %zu character limit",
|
|
label, sizeof(slot->label) - 1);
|
|
strncpy(slot->label, label, sizeof(slot->label) - 1);
|
|
slot->label[sizeof(slot->label) - 1] = '\0';
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_disarm_interrupt(akbasic_Runtime *obj, akbasic_InterruptSource source)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in disarm_interrupt");
|
|
FAIL_ZERO_RETURN(errctx, (source >= 0 && source < AKBASIC_MAX_INTERRUPTS),
|
|
AKBASIC_ERR_BOUNDS, "Interrupt source %d is outside 0..%d",
|
|
(int)source, AKBASIC_MAX_INTERRUPTS - 1);
|
|
memset(&obj->interrupts[source], 0, sizeof(obj->interrupts[source]));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_raise_interrupt(akbasic_Runtime *obj, akbasic_InterruptSource source)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in raise_interrupt");
|
|
FAIL_ZERO_RETURN(errctx, (source >= 0 && source < AKBASIC_MAX_INTERRUPTS),
|
|
AKBASIC_ERR_BOUNDS, "Interrupt source %d is outside 0..%d",
|
|
(int)source, AKBASIC_MAX_INTERRUPTS - 1);
|
|
/*
|
|
* An unarmed source records nothing. That is what lets a backend raise
|
|
* unconditionally every frame without first asking what the script has
|
|
* subscribed to -- and it means a program that arms a handler later does not
|
|
* immediately inherit a collision from before it was interested.
|
|
*/
|
|
if ( obj->interrupts[source].armed ) {
|
|
obj->interrupts[source].pending = true;
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_service_interrupts(akbasic_Runtime *obj, bool *entered)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
akbasic_Interrupt *slot = NULL;
|
|
int64_t target = 0;
|
|
int64_t returnline = 0;
|
|
int i = 0;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in service_interrupts");
|
|
if ( entered != NULL ) {
|
|
*entered = false;
|
|
}
|
|
/* An interrupt does not interrupt an interrupt. */
|
|
if ( obj->handlerenv != NULL || obj->environment == NULL ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
for ( i = 0; i < AKBASIC_MAX_INTERRUPTS; i++ ) {
|
|
if ( obj->interrupts[i].armed && obj->interrupts[i].pending ) {
|
|
break;
|
|
}
|
|
}
|
|
if ( i == AKBASIC_MAX_INTERRUPTS ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
slot = &obj->interrupts[i];
|
|
|
|
/*
|
|
* Resolve now rather than at arm time, so a LABEL that re-files itself as the
|
|
* program runs moves the handler with it.
|
|
*/
|
|
target = slot->line;
|
|
if ( slot->label[0] != '\0' ) {
|
|
PASS(errctx, akbasic_environment_get_label(obj->environment, slot->label, &target));
|
|
}
|
|
FAIL_ZERO_RETURN(errctx, (target > 0 && target < AKBASIC_MAX_SOURCE_LINES),
|
|
AKBASIC_ERR_BOUNDS,
|
|
"Interrupt handler line %" PRId64 " is outside 1..%d",
|
|
target, AKBASIC_MAX_SOURCE_LINES - 1);
|
|
|
|
/*
|
|
* A GOSUB the program did not write. The return line is the one that was
|
|
* about to run -- nextline, not lineno, because the line counter has already
|
|
* moved on past whatever last executed.
|
|
*/
|
|
slot->pending = false;
|
|
returnline = obj->environment->nextline;
|
|
PASS(errctx, akbasic_runtime_new_environment(obj));
|
|
obj->environment->gosubReturnLine = returnline;
|
|
obj->environment->nextline = target;
|
|
obj->handlerenv = obj->environment;
|
|
if ( entered != NULL ) {
|
|
*entered = true;
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/* ------------------------------------------------------------- step loop -- */
|
|
|
|
akerr_ErrorContext *akbasic_runtime_start(akbasic_Runtime *obj, int mode)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in start");
|
|
obj->run_finished_mode = (mode == AKBASIC_MODE_REPL ? AKBASIC_MODE_REPL : AKBASIC_MODE_QUIT);
|
|
PASS(errctx, akbasic_runtime_set_mode(obj, mode));
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_load(akbasic_Runtime *obj, const char *source)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
char line[AKBASIC_MAX_LINE_LENGTH];
|
|
char scanned[AKBASIC_MAX_LINE_LENGTH];
|
|
const char *cursor = NULL;
|
|
const char *eol = NULL;
|
|
size_t length = 0;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in load");
|
|
FAIL_ZERO_RETURN(errctx, (source != NULL), AKERR_NULLPOINTER, "NULL source in load");
|
|
|
|
for ( cursor = source; *cursor != '\0'; cursor = (*eol == '\0' ? eol : eol + 1) ) {
|
|
eol = strchr(cursor, '\n');
|
|
if ( eol == NULL ) {
|
|
eol = cursor + strlen(cursor);
|
|
}
|
|
length = (size_t)(eol - cursor);
|
|
if ( length > 0 && cursor[length - 1] == '\r' ) {
|
|
length -= 1;
|
|
}
|
|
FAIL_ZERO_RETURN(errctx, (length < sizeof(line)), AKBASIC_ERR_BOUNDS,
|
|
"Source line of %zu characters exceeds the %d character limit",
|
|
length, AKBASIC_MAX_LINE_LENGTH - 1);
|
|
memcpy(line, cursor, length);
|
|
line[length] = '\0';
|
|
if ( line[0] == '\0' ) {
|
|
continue;
|
|
}
|
|
/*
|
|
* Scanning is what picks the line number off the front and rewrites the
|
|
* line to what follows it -- the same path RUNSTREAM takes, so a program
|
|
* loaded from memory and one read from a file are filed identically.
|
|
*/
|
|
PASS(errctx, akbasic_runtime_zero(obj));
|
|
PASS(errctx, akbasic_scanner_zero(obj));
|
|
PASS(errctx, akbasic_scanner_scan(obj, line, scanned, sizeof(scanned)));
|
|
PASS(errctx, akbasic_runtime_store_line(obj, obj->environment->lineno, scanned));
|
|
}
|
|
obj->environment->nextline = 0;
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_step(akbasic_Runtime *obj)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
bool blocked = false;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in step");
|
|
|
|
/*
|
|
* Release the next queued note if its predecessor's time is up. PLAY does not
|
|
* block -- section 1.6 forbids it -- so this is what paces a tune, and it
|
|
* runs before the QUIT check so a program's last notes still come out while
|
|
* a host keeps calling step().
|
|
*/
|
|
PASS(errctx, akbasic_play_service(obj));
|
|
|
|
/*
|
|
* Sprite motion is serviced beside the note queue and for the same reason:
|
|
* MOVSPR's continuous form is a duration, not a statement, and a program
|
|
* sitting in a GETKEY should still see its sprites move. Collisions are
|
|
* looked for immediately afterwards, so a collision is reported against
|
|
* where the sprites have just been moved to rather than where they were.
|
|
*/
|
|
PASS(errctx, akbasic_sprite_service(obj));
|
|
PASS(errctx, akbasic_collision_service(obj));
|
|
|
|
if ( obj->mode == AKBASIC_MODE_QUIT ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/*
|
|
* A GETKEY with nothing typed yet holds the program here. The step still
|
|
* returns -- a host keeps its frame rate and a bounded run() still comes
|
|
* back -- it simply does not advance, which is what GETKEY means. The note
|
|
* queue above is serviced first on purpose: music should keep playing while
|
|
* a program waits for a keypress.
|
|
*/
|
|
PASS(errctx, akbasic_input_service(obj, &blocked));
|
|
if ( blocked ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
/*
|
|
* SLEEP and WAIT hold the same way GETKEY does, and the clock is refreshed
|
|
* before they are asked -- a SLEEP that read a stale clock would wake a step
|
|
* late every time.
|
|
*/
|
|
PASS(errctx, akbasic_console_update_clock(obj));
|
|
PASS(errctx, akbasic_console_service(obj, &blocked));
|
|
if ( blocked ) {
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
PASS(errctx, akbasic_runtime_zero(obj));
|
|
PASS(errctx, akbasic_scanner_zero(obj));
|
|
|
|
switch ( obj->mode ) {
|
|
case AKBASIC_MODE_RUNSTREAM:
|
|
PASS(errctx, akbasic_runtime_process_line_runstream(obj));
|
|
break;
|
|
case AKBASIC_MODE_REPL:
|
|
PASS(errctx, akbasic_runtime_process_line_repl(obj));
|
|
break;
|
|
case AKBASIC_MODE_RUN:
|
|
/*
|
|
* Between lines is the only safe place to enter a handler: a GOSUB
|
|
* injected mid-statement would have to return into the middle of a line,
|
|
* and the parser keeps no state that could resume there.
|
|
*
|
|
* A failure here is the program's -- an undefined handler label, a
|
|
* handler line out of range -- so it is reported and it stops the run,
|
|
* the same treatment a parse error gets in process_line_run(). Letting it
|
|
* out of step() would tear down the host over a script's mistake.
|
|
*/
|
|
ATTEMPT {
|
|
CATCH(errctx, akbasic_runtime_service_interrupts(obj, NULL));
|
|
} CLEANUP {
|
|
} PROCESS(errctx) {
|
|
} HANDLE_DEFAULT(errctx) {
|
|
char message[AKERR_MAX_ERROR_CONTEXT_STRING_LENGTH];
|
|
snprintf(message, sizeof(message), "%s", errctx->message);
|
|
IGNORE(akbasic_runtime_error(obj, AKBASIC_ERRCLASS_RUNTIME, message));
|
|
} FINISH(errctx, false);
|
|
if ( obj->errclass != AKBASIC_ERRCLASS_NONE ) {
|
|
break;
|
|
}
|
|
PASS(errctx, akbasic_runtime_process_line_run(obj));
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* The reference never clears runtime.errno, so the first BASIC-level error
|
|
* ends the program: in a file run, run_finished_mode is QUIT. Reproduced
|
|
* deliberately -- tests/language/array_outofbounds.txt depends on exactly one
|
|
* error line being printed and nothing after it.
|
|
*
|
|
* The clear on the way back to the REPL is *not* the reference's, and it is
|
|
* a fix rather than a deviation. A sticky errclass with run_finished_mode
|
|
* REPL means every later step re-enters REPL mode and prints READY again --
|
|
* so an interactive session that hits one runtime error and then reaches end
|
|
* of input spins forever printing READY instead of quitting, because the
|
|
* QUIT that process_line_repl() set on EOF is overwritten right here. A
|
|
* fresh prompt is a fresh statement; the error has been reported and acted
|
|
* on and there is nothing left for it to do.
|
|
*/
|
|
if ( obj->errclass != AKBASIC_ERRCLASS_NONE ) {
|
|
PASS(errctx, akbasic_runtime_set_mode(obj, obj->run_finished_mode));
|
|
if ( obj->mode == AKBASIC_MODE_REPL ) {
|
|
obj->errclass = AKBASIC_ERRCLASS_NONE;
|
|
}
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|
|
|
|
akerr_ErrorContext *akbasic_runtime_run(akbasic_Runtime *obj, int maxsteps)
|
|
{
|
|
PREPARE_ERROR(errctx);
|
|
int steps = 0;
|
|
|
|
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in run");
|
|
while ( obj->mode != AKBASIC_MODE_QUIT ) {
|
|
PASS(errctx, akbasic_runtime_step(obj));
|
|
steps += 1;
|
|
if ( maxsteps > 0 && steps >= maxsteps ) {
|
|
break;
|
|
}
|
|
}
|
|
SUCCEED_RETURN(errctx);
|
|
}
|