bytecode vm start, can print constants currently

7 files changed, 169 insertions, 2 deletions

diff --git a/run.h b/run.h
index 155b59b..291897c 100644
--- a/run.h
+++ b/run.h
@@ -3,8 +3,8 @@
 
 #include "ast.h"
 #include "ht.h"
+#include "val.h"
 
 
-int eval(Env *s, AstNode a);
 
 #endif
diff --git a/run.c b/run_old.c
index e4fa540..e4fa540 100644
--- a/run.c
+++ b/run_old.c
diff --git a/val.c b/val.c
new file mode 100644
index 0000000..4456148
--- /dev/null
+++ b/val.c
@@ -0,0 +1,16 @@
+#include <stdio.h>
+#include "val.h"
+
+void print_val(Val v) {
+	switch (v.ty) {
+	case TY_NIL:
+		printf("nil\n");
+		break;
+	case TY_NUM:
+		printf("%f\n",AS_NUM(v));
+		break;
+	case TY_BOOL:
+		printf("%s\n",AS_BOOL(v) ? "true" : "false");
+		break;
+	}
+}
diff --git a/val.h b/val.h
index 4560a1c..1f2bd8d 100644
--- a/val.h
+++ b/val.h
@@ -10,9 +10,9 @@ typedef struct _obj Obj;
 
 
 typedef enum {
+	TY_NIL,
 	TY_NUM,
 	TY_BOOL,
-	TY_NIL,
 } ValTy;
 
 struct _val {
@@ -29,11 +29,18 @@ struct _obj {
 	int foo;
 };
 
+void print_val(Val v);
+
 
 #define IS_NUM(x) (x.ty == TY_NUM)
 #define IS_BOOL(x) (x.ty == TY_BOOL)
 #define IS_NIL(x) (x.ty == NIL)
 
+#define AS_NUM(x) (x.as.d)
+#define AS_BOOL(x) (x.as.b)
 
+#define VAL_NUM(x) ((Val){.ty=TY_NUM, .as.d=x})
+#define VAL_BOOL(x) ((Val){.ty=TY_BOOL, .as.b=x})
+#define VAL_NIL ((Val){.ty=TY_NIL})
 
 #endif
diff --git a/vm b/vm
new file mode 100755
index 0000000..9ecf078
--- /dev/null
+++ b/vm
diff --git a/vm.c b/vm.c
new file mode 100644
index 0000000..00692b0
--- /dev/null
+++ b/vm.c
@@ -0,0 +1,102 @@
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+#include "val.h"
+#include "vm.h"
+
+void *M(void *p, size_t sz) {
+	if (sz == 0) {
+		free(p);
+		return NULL;
+	} else {
+		return realloc(p, sz);
+	}
+}
+
+
+Chunk chunk_new() {
+	return (Chunk){
+		.blen = 0, .bcap = 0, .b = NULL,
+		.clen = 0, .ccap = 0, .c = NULL,
+	};
+}
+size_t chunk_wbc(Chunk *ch, uint8_t byte) {
+	if (ch->blen == ch->bcap) {
+		size_t newsz = (ch->bcap == 0 ? 8 : ch->bcap * 2);
+		ch->b = M(ch->b, newsz * sizeof(uint8_t));
+		ch->bcap = newsz;
+	}
+	size_t ix = ch->blen;
+	ch->b[ix] = byte;
+	ch->blen ++;
+	return ix;
+}
+size_t chunk_wconst(Chunk *ch, Val v) {
+	if (ch->clen == ch->ccap) {
+		size_t newsz = (ch->ccap == 0 ? 8 : ch->ccap *2);
+		ch->c = M(ch->c, newsz * sizeof(Val));
+		ch->ccap = newsz;
+	}
+	size_t ix = ch->clen;
+	ch->c[ix] = v;
+	ch->clen ++;
+	return ix;
+}
+
+Vm vm_new(Chunk *ch) {
+	Vm vm = (Vm){ 
+		.ch = ch,
+		.ip = 0,
+		.sp = 0
+	};
+	for (int i = 0; i < STACKSIZE; i++) {
+		vm.stack[i] = VAL_NIL;
+	}
+	return vm;
+}
+
+
+static void runvm() {
+	Chunk ch = chunk_new();
+	chunk_wbc(&ch, OP_LOADK);
+	chunk_wbc(&ch, 1);
+	chunk_wbc(&ch, OP_PRINT);
+	chunk_wbc(&ch, OP_LOADK);
+	chunk_wbc(&ch, 2);
+	chunk_wbc(&ch, OP_LOADK);
+	chunk_wbc(&ch, 0);
+	chunk_wbc(&ch, OP_RET);
+
+	chunk_wconst(&ch, VAL_BOOL(false));
+	chunk_wconst(&ch, VAL_NIL);
+	chunk_wconst(&ch, VAL_NUM(420.69));
+
+	Vm vm = vm_new(&ch);
+#define RBYTE() (vm.ch->b[vm.ip++])
+
+	while (1) {
+		uint8_t instr = RBYTE();
+		switch (instr) {
+		case OP_RET:
+			printf("done!\n");
+			goto done;
+			break;
+		case OP_LOADK:
+			uint8_t cix = RBYTE();
+			Val v = vm.ch->c[cix];
+			print_val(v);
+			break;
+		case OP_PRINT:
+			printf("print\n");
+			break;
+		}
+	}
+	done:;
+}
+
+int main() { runvm(); }
+
+
diff --git a/vm.h b/vm.h
new file mode 100644
index 0000000..7f76e05
--- /dev/null
+++ b/vm.h
@@ -0,0 +1,42 @@
+#ifndef _vm_h
+#define _vm_h
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#include "val.h"
+
+void *M(void *p, size_t sz);
+
+typedef struct {
+	// bytecode
+	size_t blen;
+	size_t bcap;
+	uint8_t *b;
+	// constants
+	size_t clen;
+	size_t ccap;
+	Val *c;
+} Chunk;
+Chunk chunk_new();
+size_t chunk_wbc(Chunk *ch, uint8_t byte);
+size_t chunk_wconst(Chunk *ch, Val v);
+
+#define STACKSIZE 128
+typedef struct {
+	Chunk *ch;
+	size_t ip;
+	Val stack[STACKSIZE];
+	size_t sp;
+} Vm;
+Vm vm_new(Chunk *ch);
+
+typedef enum {
+	OP_RET,
+	OP_LOADK,
+	OP_PRINT,
+} Op;
+
+
+#endif