commit 17a9e4141d7cbd57dbf2e53e1f5f93f585d3b1fa
parent 2f24c0cf853b01eb060a2fbb9e9c7ff79925df28
Author: William Casarin <jb55@jb55.com>
Date: Mon, 5 Jul 2021 07:53:41 -0700
it works!
Diffstat:
3 files changed, 85 insertions(+), 25 deletions(-)
diff --git a/src/wasm.c b/src/wasm.c
@@ -79,6 +79,7 @@ static inline int is_valtype(unsigned char byte)
}
+/*
static int sizeof_valtype(enum valtype valtype)
{
switch (valtype) {
@@ -90,6 +91,7 @@ static int sizeof_valtype(enum valtype valtype)
return 0;
}
+*/
static const char *valtype_name(enum valtype valtype)
{
@@ -168,6 +170,17 @@ static inline int cursor_pushcode(struct cursor *cur, struct cursor *code)
return push_data(cur, (unsigned char*)code, sizeof(*code));
}
+static inline struct cursor *cursor_topcode(struct cursor *cur)
+{
+ assert(cur->p > cur->start);
+ return ((struct cursor*)cur->p) - 1;
+}
+
+static inline struct cursor *interp_codeptr(struct wasm_interp *interp)
+{
+ return cursor_topcode(&interp->code_stack);
+}
+
static inline int cursor_popcode(struct cursor *cur, struct cursor *code)
{
return cursor_popdata(cur, (unsigned char*)code, sizeof(*code));
@@ -186,7 +199,7 @@ static inline int offset_stack_top(struct cursor *cur)
return 0;
}
- return p[-1];
+ return *(p - sizeof(*p));
}
static void interp_error_(struct wasm_interp *p, const char *fmt, ...)
@@ -281,6 +294,7 @@ static void print_type_section(struct typesec *typesec)
}
}
+/*
static void print_func_section(struct funcsec *funcsec)
{
int i;
@@ -291,6 +305,7 @@ static void print_func_section(struct funcsec *funcsec)
}
printf("\n");
}
+*/
static const char *exportdesc_name(enum exportdesc desc)
{
@@ -331,6 +346,7 @@ static void print_export_section(struct exportsec *exportsec)
}
}
+/*
static void print_local(struct local *local)
{
printf("%d %s\n", local->n, valtype_name(local->valtype));
@@ -338,7 +354,6 @@ static void print_local(struct local *local)
static void print_func(struct func *func)
{
- /* todo: print locals */
int i;
printf("func locals (%d): \n", func->num_locals);
@@ -356,14 +371,15 @@ static void print_code_section(struct codesec *codesec)
print_func(&codesec->funcs[i]);
}
}
+*/
static void print_module(struct module *module)
{
print_type_section(&module->type_section);
- print_func_section(&module->func_section);
+ //print_func_section(&module->func_section);
print_import_section(&module->import_section);
print_export_section(&module->export_section);
- print_code_section(&module->code_section);
+ //print_code_section(&module->code_section);
}
@@ -1070,33 +1086,58 @@ fail:
return 0;
}
-static int interp_i32_add(struct wasm_interp *interp)
+static inline int interp_prep_binop(struct wasm_interp *interp, struct val *a,
+ struct val *b, struct val *c, enum valtype typ)
{
- struct val a;
- struct val b;
- struct val c;
+ c->type = typ;
- if (!cursor_popval(&interp->stack, &a)) {
+ if (!cursor_popval(&interp->stack, a)) {
interp_error(interp, "couldn't pop first val");
return 0;
}
- if (!cursor_popval(&interp->stack, &b)) {
+ if (!cursor_popval(&interp->stack, b)) {
interp_error(interp, "couldn't pop second val");
return 0;
}
- if (a.type != i32 || b.type != i32) {
- interp_error(interp, "i32_add type mismatch");
+ if (a->type != typ || b->type != typ) {
+ interp_error(interp, "type mismatch, %s != %s",
+ valtype_name(a->type), valtype_name(b->type));
return 0;
}
- c.type = i32;
+ return 1;
+}
+
+static int interp_i32_add(struct wasm_interp *interp)
+{
+ struct val a, b, c;
+
+ if (!interp_prep_binop(interp, &a, &b, &c, i32)) {
+ interp_error(interp, "add prep");
+ return 0;
+ }
+
c.i32 = a.i32 + b.i32;
return cursor_pushval(&interp->stack, &c);
}
+static int interp_i32_sub(struct wasm_interp *interp)
+{
+ struct val a, b, c;
+
+ if (!interp_prep_binop(interp, &a, &b, &c, i32)) {
+ interp_error(interp, "sub prep");
+ return 0;
+ }
+
+ c.i32 = a.i32 - b.i32;
+
+ return cursor_pushval(&interp->stack, &c);
+}
+
static inline struct val *get_local(struct wasm_interp *interp, int ind)
{
struct val *p;
@@ -1155,7 +1196,7 @@ static int interp_local_set(struct wasm_interp *interp)
return 0;
}
- if (!leb128_read(&interp->cur, &index)) {
+ if (!leb128_read(interp_codeptr(interp), &index)) {
interp_error(interp, "read index");
return 0;
}
@@ -1174,7 +1215,7 @@ static int interp_local_get(struct wasm_interp *interp)
unsigned int nlocals;
struct val *val;
- if (!leb128_read(&interp->cur, &index)) {
+ if (!leb128_read(interp_codeptr(interp), &index)) {
interp_error(interp, "index");
return 0;
}
@@ -1205,7 +1246,7 @@ static inline int interp_i32_const(struct wasm_interp *interp)
struct val val;
unsigned int read;
- if (!leb128_read(&interp->cur, &read)) {
+ if (!leb128_read(interp_codeptr(interp), &read)) {
interp_error(interp, "invalid constant value");
return 0;
}
@@ -1226,6 +1267,11 @@ static inline struct func *get_function(struct module *module, int ind)
static inline struct functype *get_function_type(struct module *module, int ind)
{
+ if (ind >= module->func_section.num_indices) {
+ return NULL;
+ }
+
+ ind = module->func_section.type_indices[ind];
if (ind >= module->type_section.num_functypes) {
return NULL;
}
@@ -1233,6 +1279,7 @@ static inline struct functype *get_function_type(struct module *module, int ind)
return &module->type_section.functypes[ind];
}
+/*
static const char *get_function_name(struct module *module, unsigned int func_index)
{
struct wexport *export;
@@ -1247,6 +1294,7 @@ static const char *get_function_name(struct module *module, unsigned int func_in
return "unknown";
}
+*/
static int prepare_call(struct wasm_interp *interp, int func_index)
{
@@ -1254,6 +1302,7 @@ static int prepare_call(struct wasm_interp *interp, int func_index)
struct functype *functype;
struct func *func;
struct val val;
+ struct cursor code;
enum valtype paramtype;
unsigned int offset;
@@ -1273,7 +1322,7 @@ static int prepare_call(struct wasm_interp *interp, int func_index)
/* get type signature to know how many locals to push as params */
if (!(functype = get_function_type(interp->module, func_index))) {
- interp_error(interp, "get function type");
+ interp_error(interp, "couldn't get function type");
return 0;
}
@@ -1303,8 +1352,8 @@ static int prepare_call(struct wasm_interp *interp, int func_index)
}
/* update current function and push it to the codestack as well */
- make_cursor(func->code, func->code + func->code_len, &interp->cur);
- if (!cursor_pushcode(&interp->code_stack, &interp->cur)) {
+ make_cursor(func->code, func->code + func->code_len, &code);
+ if (!cursor_pushcode(&interp->code_stack, &code)) {
interp_error(interp, "oob cursor_pushcode");
return 0;
}
@@ -1318,7 +1367,7 @@ static int interp_call(struct wasm_interp *interp)
{
unsigned int func_index;
- if (!leb128_read(&interp->cur, &func_index)) {
+ if (!leb128_read(interp_codeptr(interp), &func_index)) {
interp_error(interp, "read func index");
return 0;
}
@@ -1334,12 +1383,14 @@ static int interp_call(struct wasm_interp *interp)
static int interp_instr(struct wasm_interp *interp, unsigned char tag)
{
+ printf("executing 0x%x\n", tag);
switch (tag) {
case i_unreachable: return 1;
case i_nop: return 1;
case i_local_get: return interp_local_get(interp);
case i_local_set: return interp_local_set(interp);
case i_i32_add: return interp_i32_add(interp);
+ case i_i32_sub: return interp_i32_sub(interp);
case i_i32_const: return interp_i32_const(interp);
case i_call: return interp_call(interp);
default:
@@ -1357,8 +1408,8 @@ int interp_code(struct wasm_interp *interp)
int offset;
for (;;) {
- if (!pull_byte(&interp->cur, &tag)) {
- cursor_print_around(&interp->cur, 10);
+ if (!pull_byte(interp_codeptr(interp), &tag)) {
+ cursor_print_around(interp_codeptr(interp), 10);
interp_error(interp, "instr tag");
return 0;
}
@@ -1366,7 +1417,6 @@ int interp_code(struct wasm_interp *interp)
if (tag == i_end) {
cursor_popcode(&interp->code_stack, &code);
cursor_popint(&interp->locals_offsets, &offset);
- copy_cursor(&code, &interp->cur);
break;
}
diff --git a/src/wasm.h b/src/wasm.h
@@ -255,6 +255,7 @@ enum instr_tag {
i_i32_clz = 0x67,
i_i32_add = 0x6A,
+ i_i32_sub = 0x6B,
/* TODO: more instrs */
};
diff --git a/wasm/hello.wat b/wasm/hello.wat
@@ -3,12 +3,21 @@
local.get $lhs
local.get $rhs
i32.add)
+ (func $sub (param $lhs i32) (param $rhs i32) (result i32)
+ local.get $lhs
+ local.get $rhs
+ i32.sub
+ )
(func $start (result i32)
(local i32 i32)
i32.const 65537
local.set 0
local.get 0
i32.const 2
- call $add)
+ call $add
+ i32.const 3
+ call $sub
+ )
(export "start" (func $start))
- (export "add" (func $add)))
+ (export "add" (func $add))
+ (export "sub" (func $sub)))
