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Code Issues 1 Releases Wiki Activity
6e71984fc5
janet/core/vm.c
Calvin Rose f52e290206 Allow parser to parse files rather than just a repl. I think 
there are some memory leak issues (problems with gc).
2017-04-17 00:15:18 -04:00

514 lines
17 KiB
C
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#include <gst/gst.h>
/* Macros for errors in the vm */
/* Exit from the VM normally */
#define gst_exit(vm, r) return ((vm)->ret = (r), GST_RETURN_OK)
/* Bail from the VM with an error string. */
#define gst_error(vm, e) do { (vm)->ret = gst_string_cv((vm), (e)); goto vm_error; } while (0)
/* Crash. Not catchable, unlike error. */
#define gst_crash(vm, e) return ((vm)->crash = (e), GST_RETURN_CRASH)
/* Error if the condition is false */
#define gst_assert(vm, cond, e) do {if (!(cond)){gst_error((vm), (e));}} while (0)
static const char GST_NO_UPVALUE[] = "no upvalue";
static const char GST_EXPECTED_FUNCTION[] = "expected function";
static const char GST_EXPECTED_NUMBER_ROP[] = "expected right operand to be number";
static const char GST_EXPECTED_NUMBER_LOP[] = "expected left operand to be number";
/* Start running the VM from where it left off. Continue running
* until the stack size is smaller than minStackSize. */
static int gst_continue_size(Gst *vm, uint32_t stackBase) {
/* VM state */
GstValue *stack;
GstValue temp, v1, v2;
uint16_t *pc;
/* Intialize local state */
stack = vm->thread->data + vm->thread->count;
pc = gst_frame_pc(stack);
/* Main interpreter loop */
for (;;) {
switch (*pc) {
default:
gst_error(vm, "unknown opcode");
break;
case GST_OP_FLS: /* Load False */
temp.type = GST_BOOLEAN;
temp.data.boolean = 0;
stack[pc[1]] = temp;
pc += 2;
continue;
case GST_OP_TRU: /* Load True */
temp.type = GST_BOOLEAN;
temp.data.boolean = 1;
stack[pc[1]] = temp;
pc += 2;
continue;
case GST_OP_NIL: /* Load Nil */
temp.type = GST_NIL;
stack[pc[1]] = temp;
pc += 2;
continue;
case GST_OP_I16: /* Load Small Integer */
temp.type = GST_NUMBER;
temp.data.number = ((int16_t *)(pc))[2];
stack[pc[1]] = temp;
pc += 3;
continue;
case GST_OP_UPV: /* Load Up Value */
case GST_OP_SUV: /* Set Up Value */
{
GstValue *upv;
GstFunction *fn;
GstFuncEnv *env;
uint16_t level = pc[2];
temp = gst_frame_callee(stack);
gst_assert(vm, temp.type == GST_FUNCTION, GST_EXPECTED_FUNCTION);
fn = temp.data.function;
if (level == 0)
upv = stack + pc[3];
else {
while (fn && --level)
fn = fn->parent;
gst_assert(vm, fn, GST_NO_UPVALUE);
env = fn->env;
if (env->thread)
upv = env->thread->data + env->stackOffset + pc[3];
else
upv = env->values + pc[3];
}
if (pc[0] == GST_OP_UPV) {
stack[pc[1]] = *upv;
} else {
*upv = stack[pc[1]];
}
pc += 4;
}
continue;
case GST_OP_JIF: /* Jump If */
if (gst_truthy(stack[pc[1]])) {
pc += 4;
} else {
pc += *((int32_t *)(pc + 2));
}
continue;
case GST_OP_JMP: /* Jump */
pc += *((int32_t *)(pc + 1));
continue;
case GST_OP_CST: /* Load constant value */
v1 = gst_frame_callee(stack);
gst_assert(vm, v1.type == GST_FUNCTION, GST_EXPECTED_FUNCTION);
if (pc[2] > v1.data.function->def->literalsLen)
gst_error(vm, GST_NO_UPVALUE);
stack[pc[1]] = v1.data.function->def->literals[pc[2]];
pc += 3;
continue;
case GST_OP_I32: /* Load 32 bit integer */
temp.type = GST_NUMBER;
temp.data.number = *((int32_t *)(pc + 2));
stack[pc[1]] = temp;
pc += 4;
continue;
case GST_OP_F64: /* Load 64 bit float */
temp.type = GST_NUMBER;
temp.data.number = (GstNumber) *((double *)(pc + 2));
stack[pc[1]] = temp;
pc += 6;
continue;
case GST_OP_MOV: /* Move Values */
stack[pc[1]] = stack[pc[2]];
pc += 3;
continue;
case GST_OP_CLN: /* Create closure from constant FuncDef */
{
GstFunction *fn;
v1 = gst_frame_callee(stack);
if (v1.type != GST_FUNCTION)
gst_error(vm, GST_EXPECTED_FUNCTION);
if (gst_frame_env(stack) == NULL) {
gst_frame_env(stack) = gst_alloc(vm, sizeof(GstFuncEnv));
gst_frame_env(stack)->thread = vm->thread;
gst_frame_env(stack)->stackOffset = vm->thread->count;
gst_frame_env(stack)->values = NULL;
}
if (pc[2] > v1.data.function->def->literalsLen)
gst_error(vm, GST_NO_UPVALUE);
temp = v1.data.function->def->literals[pc[2]];
if (temp.type != GST_FUNCDEF)
gst_error(vm, "cannot create closure");
fn = gst_alloc(vm, sizeof(GstFunction));
fn->def = temp.data.def;
fn->parent = v1.data.function;
fn->env = gst_frame_env(stack);
temp.type = GST_FUNCTION;
temp.data.function = fn;
stack[pc[1]] = temp;
pc += 3;
}
break;
case GST_OP_TRY: /* Begin try block */
gst_frame_errloc(stack) = pc[1];
gst_frame_errjmp(stack) = pc + *(uint32_t *)(pc + 2);
pc += 4;
continue;
case GST_OP_UTY: /* End try block */
gst_frame_errjmp(stack) = NULL;
pc++;
continue;
case GST_OP_RTN: /* Return nil */
stack = gst_thread_popframe(vm, vm->thread);
if (vm->thread->count < stackBase) {
vm->ret.type = GST_NIL;
return GST_RETURN_OK;
}
pc = gst_frame_pc(stack);
stack[gst_frame_ret(stack)].type = GST_NIL;
continue;
case GST_OP_RET: /* Return */
temp = stack[pc[1]];
stack = gst_thread_popframe(vm, vm->thread);
if (vm->thread->count < stackBase) {
vm->ret = temp;
return GST_RETURN_OK;
}
pc = gst_frame_pc(stack);
stack[gst_frame_ret(stack)] = temp;
continue;
case GST_OP_CAL: /* Call */
case GST_OP_TCL: /* Tail call */
{
GstValue *oldStack;
temp = stack[pc[1]];
int isTCall = *pc == GST_OP_TCL;
uint32_t i, arity, offset, size;
uint16_t ret = pc[2];
offset = isTCall ? 3 : 4;
arity = pc[offset - 1];
/* Push new frame */
if (temp.type != GST_FUNCTION && temp.type != GST_CFUNCTION)
gst_error(vm, GST_EXPECTED_FUNCTION);
stack = gst_thread_beginframe(vm, vm->thread, temp, arity);
oldStack = stack - GST_FRAME_SIZE - gst_frame_prevsize(stack);
/* Write arguments */
size = gst_frame_size(stack);
for (i = 0; i < arity; ++i)
stack[i + size - arity] = oldStack[pc[offset + i]];
/* Finish new frame */
gst_thread_endframe(vm, vm->thread);
/* Check tail call - if so, replace frame. */
if (isTCall) {
stack = gst_thread_tail(vm, vm->thread);
} else {
gst_frame_ret(oldStack) = ret;
}
/* Call function */
temp = gst_frame_callee(stack);
if (temp.type == GST_FUNCTION) {
/* Save pc and set new pc */
if (!isTCall)
gst_frame_pc(oldStack) = pc + offset + arity;
pc = temp.data.function->def->byteCode;
} else {
int status;
gst_frame_pc(stack) = pc;
vm->ret.type = GST_NIL;
status = temp.data.cfunction(vm);
stack = gst_thread_popframe(vm, vm->thread);
if (status == GST_RETURN_OK) {
if (vm->thread->count < stackBase) {
return status;
} else {
stack[gst_frame_ret(stack)] = vm->ret;
if (isTCall)
pc = gst_frame_pc(stack);
else
pc += offset + arity;
}
} else {
goto vm_error;
}
}
}
break;
/* Faster implementations of standard functions
* These opcodes are nto strictlyre required and can
* be reimplemented with stanard library functions */
case GST_OP_ERR: /* Throw error */
vm->ret = stack[pc[1]];
goto vm_error;
#define OP_BINARY_MATH(op) \
v1 = stack[pc[2]]; \
v2 = stack[pc[3]]; \
gst_assert(vm, v1.type == GST_NUMBER, GST_EXPECTED_NUMBER_LOP); \
gst_assert(vm, v2.type == GST_NUMBER, GST_EXPECTED_NUMBER_ROP); \
temp.type = GST_NUMBER; \
temp.data.number = v1.data.number op v2.data.number; \
stack[pc[1]] = temp; \
pc += 4; \
continue;
case GST_OP_ADD: /* Addition */
OP_BINARY_MATH(+)
case GST_OP_SUB: /* Subtraction */
OP_BINARY_MATH(-)
case GST_OP_MUL: /* Multiplication */
OP_BINARY_MATH(*)
case GST_OP_DIV: /* Division */
OP_BINARY_MATH(/)
#undef OP_BINARY_MATH
case GST_OP_NOT: /* Boolean unary (Boolean not) */
temp.type = GST_BOOLEAN;
temp.data.boolean = !gst_truthy(stack[pc[2]]);
stack[pc[1]] = temp;
pc += 3;
continue;
case GST_OP_NEG: /* Unary negation */
v1 = stack[pc[2]];
gst_assert(vm, v1.type == GST_NUMBER, GST_EXPECTED_NUMBER_LOP);
temp.type = GST_NUMBER;
temp.data.number = -v1.data.number;
stack[pc[1]] = temp;
pc += 3;
continue;
case GST_OP_INV: /* Unary multiplicative inverse */
v1 = stack[pc[2]];
gst_assert(vm, v1.type == GST_NUMBER, GST_EXPECTED_NUMBER_LOP);
temp.type = GST_NUMBER;
temp.data.number = 1 / v1.data.number;
stack[pc[1]] = temp;
pc += 3;
continue;
case GST_OP_EQL: /* Equality */
temp.type = GST_BOOLEAN;
temp.data.boolean = gst_equals(stack[pc[2]], stack[pc[3]]);
stack[pc[1]] = temp;
pc += 4;
continue;
case GST_OP_LTN: /* Less Than */
temp.type = GST_BOOLEAN;
temp.data.boolean = (gst_compare(stack[pc[2]], stack[pc[3]]) == -1);
stack[pc[1]] = temp;
pc += 4;
continue;
case GST_OP_LTE: /* Less Than or Equal to */
temp.type = GST_BOOLEAN;
temp.data.boolean = (gst_compare(stack[pc[2]], stack[pc[3]]) != 1);
stack[pc[1]] = temp;
pc += 4;
continue;
case GST_OP_ARR: /* Array literal */
{
uint32_t i;
uint32_t arrayLen = pc[2];
GstArray *array = gst_array(vm, arrayLen);
array->count = arrayLen;
for (i = 0; i < arrayLen; ++i)
array->data[i] = stack[pc[3 + i]];
temp.type = GST_ARRAY;
temp.data.array = array;
stack[pc[1]] = temp;
pc += 3 + arrayLen;
}
break;
case GST_OP_DIC: /* Object literal */
{
uint32_t i = 3;
uint32_t kvs = pc[2];
GstObject *o = gst_object(vm, 2 * kvs + 2);
kvs = kvs + 3;
while (i < kvs) {
v1 = stack[pc[i++]];
v2 = stack[pc[i++]];
gst_object_put(vm, o, v1, v2);
}
temp.type = GST_OBJECT;
temp.data.object = o;
stack[pc[1]] = temp;
pc += kvs;
}
break;
case GST_OP_TUP: /* Tuple literal */
{
uint32_t i;
uint32_t len = pc[2];
GstValue *tuple = gst_tuple_begin(vm, len);
for (i = 0; i < len; ++i)
tuple[i] = stack[pc[3 + i]];
temp.type = GST_TUPLE;
temp.data.tuple = gst_tuple_end(vm, tuple);
stack[pc[1]] = temp;
pc += 3 + len;
}
break;
case GST_OP_YLD: /* Yield from function */
temp = stack[pc[1]];
if (vm->thread->parent == NULL) {
vm->ret = temp;
return GST_RETURN_OK;
}
gst_frame_pc(stack) = pc + 2;
vm->thread = vm->thread->parent;
stack = vm->thread->data + vm->thread->count;
pc = gst_frame_pc(stack);
break;
/* Handle errors from c functions and vm opcodes */
vm_error:
if (stack == NULL)
return GST_RETURN_ERROR;
while (gst_frame_errjmp(stack) == NULL) {
stack = gst_thread_popframe(vm, vm->thread);
if (vm->thread->count < stackBase)
return GST_RETURN_ERROR;
}
pc = gst_frame_errjmp(stack);
stack[gst_frame_errloc(stack)] = vm->ret;
break;
} /* end switch */
/* Check for collection every cycle. If the instruction definitely does
* not allocate memory, it can use continue instead of break to
* skip this check */
gst_maybe_collect(vm);
} /* end for */
}
/* Continue running the VM after it has stopped */
int gst_continue(Gst *vm) {
return gst_continue_size(vm, vm->thread->count);
}
/* Run the vm with a given function. This function is
* called to start the vm. */
int gst_run(Gst *vm, GstValue callee) {
int status;
GstValue *stack;
vm->thread = gst_thread(vm, callee, 64);
if (vm->thread == NULL)
return GST_RETURN_CRASH;
stack = gst_thread_stack(vm->thread);
/* If callee was not actually a function, get the delegate function */
callee = gst_frame_callee(stack);
if (callee.type == GST_CFUNCTION) {
vm->ret.type = GST_NIL;
status = callee.data.cfunction(vm);
gst_thread_popframe(vm, vm->thread);
return status;
} else {
return gst_continue(vm);
}
}
/* Get an argument from the stack */
GstValue gst_arg(Gst *vm, uint16_t index) {
GstValue *stack = gst_thread_stack(vm->thread);
uint16_t frameSize = gst_frame_size(stack);
if (frameSize <= index) {
GstValue ret;
ret.type = GST_NIL;
return ret;
}
return stack[index];
}
/* Put a value on the stack */
void gst_set_arg(Gst* vm, uint16_t index, GstValue x) {
GstValue *stack = gst_thread_stack(vm->thread);
uint16_t frameSize = gst_frame_size(stack);
if (frameSize <= index) return;
stack[index] = x;
}
/* Get the size of the VMStack */
uint16_t gst_count_args(Gst *vm) {
GstValue *stack = gst_thread_stack(vm->thread);
return gst_frame_size(stack);
}
/* Initialize the VM */
void gst_init(Gst *vm) {
vm->ret.type = GST_NIL;
vm->crash = NULL;
/* Garbage collection */
vm->blocks = NULL;
vm->nextCollection = 0;
/* Setting memoryInterval to zero currently forces
* a collection pretty much every cycle, which is
* obviously horrible for performance. It helps ensure
* there are no memory bugs during dev */
vm->memoryInterval = 2000;
vm->black = 0;
/* Add thread */
vm->thread = NULL;
/* Set up global env */
vm->rootenv = NULL;
/* Set up scratch memory */
vm->scratch = NULL;
vm->scratch_len = 0;
/* Set up the cache */
vm->cache = gst_raw_calloc(1, 128 * sizeof(GstValue));
vm->cache_capacity = vm->cache == NULL ? 0 : 128;
vm->cache_count = 0;
vm->cache_deleted = 0;
}
/* Clear all memory associated with the VM */
void gst_deinit(Gst *vm) {
gst_clear_memory(vm);
vm->thread = NULL;
vm->rootenv = NULL;
vm->ret.type = GST_NIL;
vm->scratch = NULL;
vm->scratch_len = 0;
/* Deinit the cache */
gst_raw_free(vm->cache);
vm->cache = NULL;
vm->cache_count = 0;
vm->cache_capacity = 0;
vm->cache_deleted = 0;
}
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