runtime: temporary implementation of arithmetic bytecode evaluation

bshell/runtime/eval.c

@@ -0,0 +1,91 @@
+#include "../status.h"
+#include "runtime.h"
+#include "scope.h"
+
+#include <stdio.h>
+
+static enum bshell_status eval_instruction(
+	struct bshell_runtime *rt,
+	struct runtime_scope *scope,
+	bshell_instruction instr)
+{
+	fx_value x, y, z;
+	enum bshell_opcode opcode;
+	uint32_t arg;
+	bshell_instruction_decode(instr, &opcode, &arg);
+
+	switch (opcode) {
+	case OPCODE_LDC_INT:
+		x = FX_INT(arg);
+		runtime_scope_push_value(scope, x);
+		break;
+	case OPCODE_ADD:
+		x = runtime_scope_pop_value(scope);
+		y = runtime_scope_pop_value(scope);
+		z = FX_INT(y.v_int + x.v_int);
+		runtime_scope_push_value(scope, z);
+		break;
+	case OPCODE_SUB:
+		x = runtime_scope_pop_value(scope);
+		y = runtime_scope_pop_value(scope);
+		z = FX_INT(y.v_int - x.v_int);
+		runtime_scope_push_value(scope, z);
+		break;
+	case OPCODE_MUL:
+		x = runtime_scope_pop_value(scope);
+		y = runtime_scope_pop_value(scope);
+		z = FX_INT(y.v_int * x.v_int);
+		runtime_scope_push_value(scope, z);
+		break;
+	case OPCODE_DIV:
+		x = runtime_scope_pop_value(scope);
+		y = runtime_scope_pop_value(scope);
+		z = FX_INT(y.v_int / x.v_int);
+		runtime_scope_push_value(scope, z);
+		break;
+	default:
+		fprintf(stderr,
+		        "RUNTIME: encountered unknown opcode %02x\n",
+		        opcode);
+		return BSHELL_ERR_BAD_FORMAT;
+	}
+
+	scope->s_ip++;
+	return BSHELL_SUCCESS;
+}
+
+static fx_value runtime_eval(struct bshell_runtime *rt)
+{
+	enum bshell_status status = BSHELL_SUCCESS;
+	while (status == BSHELL_SUCCESS) {
+		struct runtime_scope *scope = runtime_get_scope(rt);
+		if (scope->s_ip >= scope->s_nr_instr) {
+			break;
+		}
+
+		bshell_instruction instr = scope->s_instr[scope->s_ip];
+		status = eval_instruction(rt, scope, instr);
+	}
+
+	struct runtime_scope *scope = runtime_get_scope(rt);
+	return runtime_scope_pop_value(scope);
+}
+
+fx_value bshell_runtime_eval_global(
+	struct bshell_runtime *rt,
+	bshell_scriptblock *block)
+{
+	enum bshell_status status = BSHELL_SUCCESS;
+	runtime_scope_set_block(rt->rt_global, block);
+	return runtime_eval(rt);
+}
+
+fx_value bshell_runtime_eval_script(
+	struct bshell_runtime *rt,
+	bshell_scriptblock *block)
+{
+	runtime_push_scope(rt, RUNTIME_SCOPE_SCRIPT, block);
+	fx_value result = runtime_eval(rt);
+	runtime_pop_scope(rt);
+	return result;
+}

bshell/runtime/runtime.c

@@ -0,0 +1,25 @@
+#include "runtime.h"
+
+#include "scope.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+struct bshell_runtime *bshell_runtime_create(void)
+{
+	struct bshell_runtime *out = malloc(sizeof *out);
+	if (!out) {
+		return NULL;
+	}
+
+	memset(out, 0x0, sizeof *out);
+
+	out->rt_global = runtime_push_scope(out, RUNTIME_SCOPE_GLOBAL, NULL);
+
+	return out;
+}
+
+void bshell_runtime_destroy(struct bshell_runtime *rt)
+{
+	free(rt);
+}

bshell/runtime/runtime.h

@@ -0,0 +1,26 @@
+#ifndef RUNTIME_RUNTIME_H_
+#define RUNTIME_RUNTIME_H_
+
+#include "../script-block.h"
+
+#include <fx/queue.h>
+#include <fx/value.h>
+
+struct runtime_scope;
+
+struct bshell_runtime {
+	struct runtime_scope *rt_global;
+	fx_queue rt_scope;
+};
+
+extern struct bshell_runtime *bshell_runtime_create(void);
+extern void bshell_runtime_destroy(struct bshell_runtime *rt);
+
+extern fx_value bshell_runtime_eval_global(
+	struct bshell_runtime *rt,
+	bshell_scriptblock *block);
+extern fx_value bshell_runtime_eval_script(
+	struct bshell_runtime *rt,
+	bshell_scriptblock *block);
+
+#endif

bshell/runtime/scope.c

@@ -0,0 +1,80 @@
+#include "scope.h"
+
+#include "runtime.h"
+
+#include <fx/vector.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct runtime_scope *runtime_push_scope(
+	struct bshell_runtime *rt,
+	enum runtime_scope_type type,
+	bshell_scriptblock *block)
+{
+	struct runtime_scope *out = malloc(sizeof *out);
+	if (!out) {
+		return NULL;
+	}
+
+	memset(out, 0x0, sizeof *out);
+
+	out->s_type = type;
+
+	if (block) {
+		runtime_scope_set_block(out, block);
+	}
+
+	fx_queue_push_back(&rt->rt_scope, &out->s_entry);
+	return out;
+}
+
+void runtime_pop_scope(struct bshell_runtime *rt)
+{
+	fx_queue_entry *entry = fx_queue_pop_back(&rt->rt_scope);
+	if (!entry) {
+		return;
+	}
+
+	struct runtime_scope *scope = fx_unbox(
+		struct runtime_scope,
+		entry,
+		s_entry);
+	/* TODO */
+	free(scope);
+}
+
+struct runtime_scope *runtime_get_scope(struct bshell_runtime *rt)
+{
+	fx_queue_entry *entry = fx_queue_last(&rt->rt_scope);
+	if (!entry) {
+		return NULL;
+	}
+
+	return fx_unbox(struct runtime_scope, entry, s_entry);
+}
+
+void runtime_scope_push_value(struct runtime_scope *scope, fx_value value)
+{
+	fx_value *slot = fx_vector_emplace_back(scope->s_stack, NULL);
+	if (!slot) {
+		return;
+	}
+
+	memcpy(slot, &value, sizeof value);
+}
+
+fx_value runtime_scope_pop_value(struct runtime_scope *scope)
+{
+	fx_value v = scope->s_stack.items[scope->s_stack.count - 1];
+	fx_vector_pop_back(scope->s_stack, NULL);
+	return v;
+}
+
+void runtime_scope_set_block(
+	struct runtime_scope *scope,
+	bshell_scriptblock *block)
+{
+	scope->s_block = block;
+	bshell_scriptblock_get_text(block, &scope->s_instr, &scope->s_nr_instr);
+	bshell_scriptblock_get_pool(block, &scope->s_pool, &scope->s_nr_pool);
+}

bshell/runtime/scope.h

@@ -0,0 +1,48 @@
+#ifndef RUNTIME_SCOPE_H_
+#define RUNTIME_SCOPE_H_
+
+#include "../script-block.h"
+
+#include <fx/namemap.h>
+#include <fx/queue.h>
+#include <fx/vector.h>
+
+struct bshell_runtime;
+
+enum runtime_scope_type {
+	RUNTIME_SCOPE_OTHER = 0,
+	RUNTIME_SCOPE_SCRIPT,
+	RUNTIME_SCOPE_GLOBAL,
+};
+
+struct runtime_scope {
+	enum runtime_scope_type s_type;
+	fx_queue_entry s_entry;
+	fx_namemap s_vars;
+	FX_VECTOR_DECLARE(fx_value, s_stack);
+	size_t s_ip;
+
+	bshell_scriptblock *s_block;
+	bshell_instruction *s_instr;
+	size_t s_nr_instr;
+	fx_value *s_pool;
+	size_t s_nr_pool;
+};
+
+extern struct runtime_scope *runtime_push_scope(
+	struct bshell_runtime *rt,
+	enum runtime_scope_type type,
+	bshell_scriptblock *block);
+extern void runtime_pop_scope(struct bshell_runtime *rt);
+extern struct runtime_scope *runtime_get_scope(struct bshell_runtime *rt);
+
+extern void runtime_scope_push_value(
+	struct runtime_scope *scope,
+	fx_value value);
+extern fx_value runtime_scope_pop_value(struct runtime_scope *scope);
+
+extern void runtime_scope_set_block(
+	struct runtime_scope *scope,
+	bshell_scriptblock *block);
+
+#endif