Files
wipforth/asm.js

1452 lines
42 KiB
JavaScript

const HEADER = [
0x00, 0x61, 0x73, 0x6d,
0x01, 0x00, 0x00, 0x00
];
const LINE_END = "\n"
class Tokenizer {
constructor() {
this.delims = new Set([" ", "\r", "\n", "\t"]);
this.skips = new Set([" ", "\r", "\t"]);
this.comment_start = ";";
this.string_quote = '"';
this.buffer = [];
this.comment = false;
this.string = false;
this.cursor = 0;
}
find(pred) {
for (let i = this.cursor; i < this.buffer.length; ++i) {
if (pred(this.buffer[i]))
return i;
}
return null;
}
skip() {
const idx = this.find((cp) => !this.skips.has(cp));
this.cursor = idx == null ? this.buffer.length : idx;
}
next_string() {
const idx = this.find((cp) => cp == this.string_quote);
if (idx == null) {
this.string = true;
} else {
const string = this.buffer.slice(this.cursor, idx).join("");
this.cursor = idx + 1;
this.string = false;
return { string: string };
}
}
next() {
if (this.string)
return this.next_string();
this.skip();
if (this.buffer[this.cursor] == LINE_END) {
++this.cursor;
return LINE_END;
}
if (this.buffer[this.cursor] == this.string_quote) {
++this.cursor;
return this.next_string();
}
const idx = this.find((cp) => this.delims.has(cp));
if (idx != null) {
const token = this.buffer.slice(this.cursor, idx).join("");
this.cursor = idx;
return token;
}
}
*handle(src) {
this.buffer.push(...src);
let token;
while (token = this.next()) {
if (token.string == undefined
&& token.startsWith(this.comment_start)) {
this.comment = true;
} else if (this.comment && token == LINE_END) {
this.comment = false;
yield token;
} else if (!this.comment) {
yield token;
}
}
}
}
const State = Object.freeze({
TOP: 0,
EXPORT: 1,
FUNC: 2,
RESULT: 3,
PARAM_NAME: 4,
PARAM_TYPE: 5,
LOCAL_NAME: 6,
LOCAL_TYPE: 7,
MEM_NAME: 8,
MEM_INIT: 9,
MEM_MAX: 10,
MEM_FLAGS: 11,
IMPORT_NAME: 12,
IMPORT_MOD: 13,
IMPORT_FIELD: 14,
GLOBAL_NAME: 15,
GLOBAL_TYPE: 16,
GLOBAL_INIT: 17,
AT_MEM: 18,
AT_ADDR: 19,
BYTE: 20,
WORD: 21,
UTF8: 22,
ALIGN: 23,
DEF_NAME: 24,
DEF_VALUE: 25,
BLOCK_NAME: 26,
BLOCK_TYPE: 27,
TYPE_NAME: 28,
TYPE_PARAM: 29,
TYPE_RESULT: 30,
TABLE_NAME: 31,
TABLE_SIZE: 32,
ELEM_TABLE: 33,
ELEM_ELEM: 34,
ELEM_LABEL: 35,
ZERO: 36,
});
const Action = Object.freeze({
APPEND: 0,
EXPORT: 1,
FUNC: 2,
RESULT: 3,
PARAM: 4,
SYMBOL: 5,
LOCAL: 6,
MEM: 7,
IMPORT: 8,
GLOBAL: 9,
AT: 10,
DATA: 11,
ALIGN: 12,
DEF: 13,
LABEL: 14,
ENTER: 16,
EXIT: 17,
ELSE: 18,
TYPE: 19,
TABLE: 20,
ELEM: 21,
});
const types = {
"void": 0x40,
"func": 0x60,
"funcref": 0x70,
"f32": 0x7d,
"i32": 0x7f,
};
const opcodes = {
"block": 0x02,
"loop": 0x03,
"if": 0x04,
"else": 0x05,
"end": 0x0b,
"br": 0x0c,
"br_if": 0x0d,
"call": 0x10,
"call_indirect": 0x11,
"drop": 0x0a,
"local.get": 0x20,
"local.set": 0x21,
"local.tee": 0x22,
"global.get": 0x23,
"global.set": 0x24,
"i32.load": 0x28,
"i32.load8_u": 0x2d,
"i32.store": 0x36,
"i32.store8": 0x3a,
"i32.const": 0x41,
"i64.const": 0x42,
"i32.eqz": 0x45,
"i32.eq": 0x46,
"i32.ne": 0x47,
"i32.lt_s": 0x48,
"i32.lt_u": 0x49,
"i32.gt_s": 0x4a,
"i32.gt_u": 0x4b,
"i32.le_s": 0x4c,
"i32.le_u": 0x4d,
"i32.ge_s": 0x4e,
"i32.ge_u": 0x4f,
"i32.add": 0x6a,
"i32.sub": 0x6b,
"i32.mul": 0x6c,
"i32.div_s": 0x6d,
"i32.rem_s": 0x6f,
"i32.and": 0x71,
"i32.or": 0x72,
"i32.xor": 0x73,
"i32.shl": 0x74,
"i32.shr_s": 0x75,
"i32.shr_u": 0x76,
// Threads instructions
"memory.atomic.notify": [ 0xfe, 0x00 ],
"memory.atomic.wait32": [ 0xfe, 0x01 ],
"i32.atomic.load": [ 0xfe, 0x10 ],
"i32.atomic.load8_u": [ 0xfe, 0x12 ],
"i32.atomic.store": [ 0xfe, 0x17 ],
"i32.atomic.store8": [ 0xfe, 0x19 ],
};
const mem_flags = {
"max": 1,
"shared": 2,
"64": 4,
};
const const_opcodes = {
[types["i32"]]: opcodes["i32.const"],
};
class Parser {
constructor(encoder) {
this.encoder = encoder;
this.tokens = [];
this.tokenizer = new Tokenizer();
this.state = State.TOP;
this.directives = {
".export": State.EXPORT,
".func": State.FUNC,
".result": State.RESULT,
".param": State.PARAM_NAME,
".local": State.LOCAL_NAME,
".mem": State.MEM_NAME,
".import": State.IMPORT_NAME,
".global": State.GLOBAL_NAME,
".at": State.AT_MEM,
".byte": State.BYTE,
".word": State.WORD,
".utf8": State.UTF8,
".align": State.ALIGN,
".def": State.DEF_NAME,
".type": State.TYPE_NAME,
".table": State.TABLE_NAME,
".elem": State.ELEM_TABLE,
".zero": State.ZERO,
};
this.blocks = new Set(["block", "loop", "if"]);
this.handlers = {
[State.TOP]: (token) => this.token_top(token),
[State.EXPORT]: (token) => this.token_export(token),
[State.FUNC]: (token) => this.token_func(token),
[State.RESULT]: (token) => this.token_result(token),
[State.PARAM_NAME]: (token) => this.token_param_name(token),
[State.PARAM_TYPE]: (token) => this.token_param_type(token),
[State.LOCAL_NAME]: (token) => this.token_local_name(token),
[State.LOCAL_TYPE]: (token) => this.token_local_type(token),
[State.MEM_NAME]: (token) => this.token_mem_name(token),
[State.MEM_INIT]: (token) => this.token_mem_init(token),
[State.MEM_MAX]: (token) => this.token_mem_max(token),
[State.MEM_FLAGS]: (token) => this.token_mem_flags(token),
[State.IMPORT_NAME]: (token) => this.token_import_name(token),
[State.IMPORT_MOD]: (token) => this.token_import_mod(token),
[State.IMPORT_FIELD]: (token) => this.token_import_field(token),
[State.GLOBAL_NAME]: (token) => this.token_global_name(token),
[State.GLOBAL_TYPE]: (token) => this.token_global_type(token),
[State.GLOBAL_INIT]: (token) => this.token_global_init(token),
[State.AT_MEM]: (token) => this.token_at_mem(token),
[State.AT_ADDR]: (token) => this.token_at_addr(token),
[State.BYTE]: (token) => this.token_byte(token),
[State.WORD]: (token) => this.token_word(token),
[State.UTF8]: (token) => this.token_utf8(token),
[State.ALIGN]: (token) => this.token_align(token),
[State.DEF_NAME]: (token) => this.token_def_name(token),
[State.DEF_VALUE]: (token) => this.token_def_value(token),
[State.BLOCK_NAME]: (token) => this.token_block_name(token),
[State.BLOCK_TYPE]: (token) => this.token_block_type(token),
[State.TYPE_NAME]: (token) => this.token_type_name(token),
[State.TYPE_PARAM]: (token) => this.token_type_param(token),
[State.TYPE_RESULT]: (token) => this.token_type_result(token),
[State.TABLE_NAME]: (token) => this.token_table_name(token),
[State.TABLE_SIZE]: (token) => this.token_table_size(token),
[State.ELEM_TABLE]: (token) => this.token_elem_table(token),
[State.ELEM_ELEM]: (token) => this.token_elem_elem(token),
[State.ELEM_LABEL]: (token) => this.token_elem_label(token),
[State.ZERO]: (token) => this.token_zero(token),
};
this.results = [];
this.params = {};
this.locals = {};
}
integer(token) {
let base, regex;
switch (token.slice(-1)) {
case "b": base = 2; regex = /^-?[01]+b$/; break;
case "o": base = 8; regex = /^-?[0-7]+o$/; break;
case "h": base = 16; regex = /^-?[0-9A-F]+h$/; break;
default: base = 10; regex = /^-?[0-9]+d?$/; break;
}
return regex.test(token) ? parseInt(token, base) : null;
}
translate_code(token) {
return opcodes[token] ?? this.integer(token);
}
translate_type(token) {
return types[token];
}
token_top(token) {
if (token == LINE_END)
return;
const state = this.directives[token];
if (state) {
this.state = state;
return;
}
if (token.endsWith(":"))
return { type: Action.LABEL, name: token.slice(0, -1) };
const opcode = opcodes[token];
if (this.blocks.has(token)) {
this.state = State.BLOCK_NAME;
this.block = { code: opcode };
return;
}
if (token == "else")
return { type: Action.ELSE }
if (token == "end")
return { type: Action.EXIT };
if (opcode)
return { type: Action.APPEND, opcode };
const literal = this.integer(token);
if (literal != null)
return { type: Action.APPEND, literal };
return { type: Action.SYMBOL, symbol: token };
}
token_export(token) {
this.state = State.TOP;
return { type: Action.EXPORT, name: token };
}
token_func(token) {
this.state = State.TOP;
return { type: Action.FUNC, name: token };
}
token_result(token) {
if (token == LINE_END) {
const action = { type: Action.RESULT, results: this.results };
this.state = State.TOP;
this.results = [];
return action;
} else {
this.results.push(this.translate_type(token));
}
}
token_param_name(token) {
if (token == LINE_END) {
const action = { type: Action.PARAM, params: this.params };
this.state = State.TOP;
this.params = {};
return action;
} else {
this.current_param = token;
this.state = State.PARAM_TYPE;
}
}
token_param_type(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected newline in .param: expected type");
this.state = State.TOP;
this.params = {};
} else {
this.params[this.current_param] = types[token];
this.current_param = undefined;
this.state = State.PARAM_NAME;
}
}
token_local_name(token) {
if (token == LINE_END) {
const action = { type: Action.LOCAL, locals: this.locals };
this.state = State.TOP;
this.locals = {};
return action;
} else {
this.current_local = token;
this.state = State.LOCAL_TYPE;
}
}
token_local_type(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected newline in .local: expected type");
this.state = State.TOP;
this.locals = {};
} else {
this.locals[this.current_local] = types[token];
this.current_local = undefined;
this.state = State.LOCAL_NAME;
}
}
token_mem_name(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected newline in .mem: expected name");
this.state = State.TOP;
} else {
this.mem = { flags: 0 };
this.mem_name = token;
this.state = State.MEM_INIT;
}
}
token_mem_init(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected newline in .mem: expected initial size");
this.mem = undefined;
this.mem_name = undefined;
this.state = State.TOP;
} else {
this.mem.init = this.integer(token) ?? console.error(
`ERROR: Invalid initial size ${token} in .mem`);
this.state = State.MEM_MAX;
}
}
token_mem_max(token) {
if (token == LINE_END) {
return this.mem_action();
} else {
this.mem.max = this.integer(token) ?? console.error(
`ERROR: Invalid maximum size ${token} in .mem`);
this.mem.flags |= mem_flags.max;
this.state = State.MEM_FLAGS;
}
}
token_mem_flags(token) {
if (token == LINE_END) {
return this.mem_action();
} else {
for (const flag of token.split(",")) {
this.mem.flags |= mem_flags[flag] ?? console.error(
`ERROR: Invalid flag ${flag} in .mem`);
}
this.state = State.TOP;
return this.mem_action();
}
}
token_import_name(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected end of line in .import: expected name");
this.state = State.TOP;
} else {
this.import = { name: token };
this.state = State.IMPORT_MOD;
}
}
token_import_mod(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected end of line in .import: expected name");
this.import = undefined;
this.state = State.TOP;
} else if (token.string == undefined) {
console.error(
`ERROR: Unexpected token ${token} in .import: expected`
+ " module string");
this.import = undefined;
this.state = State.TOP;
} else {
this.import.mod = token.string;
this.state = State.IMPORT_FIELD;
}
}
token_import_field(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected end of line in .import: expected name");
this.import = undefined;
this.state = State.TOP;
} else if (token.string == undefined) {
console.error(
"ERROR: Unexpected token in .import: expected field string");
this.import = undefined;
this.state = State.TOP;
} else {
this.import.field = token.string;
const action = { type: Action.IMPORT, import: this.import };
this.import = undefined;
this.state = State.TOP;
return action;
}
}
token_global_name(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected end of line in .global: expected name");
this.state = State.TOP;
} else {
this.global = {};
this.global_name = token;
this.state = State.GLOBAL_TYPE;
}
}
token_global_type(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected newline in .global: expected type");
this.global = undefined;
this.global_name = undefined;
this.state = State.TOP;
} else {
this.global.type = types[token] ?? console.error(
`ERROR: Unexpected token ${token} in .global: `
+ "expected type");
this.state = State.GLOBAL_INIT;
}
}
token_global_init(token) {
if (token == LINE_END) {
this.global.init = 0;
} else {
const value = this.integer(token) ?? console.error(
`ERROR: Unexpected token ${token} in .global: expected`
+ " initial value");
this.global.init = value;
}
const action = {
type: Action.GLOBAL,
global: { [this.global_name]: this.global }
};
this.global = undefined;
this.global_name = undefined;
this.state = State.TOP;
return action;
}
token_at_mem(token) {
this.at = { mem: token };
this.state = State.AT_ADDR;
}
token_at_addr(token) {
const value = this.integer(token);
if (value != null)
this.at.addr = value;
else
this.at.addr_symbol = token;
const action = { type: Action.AT, at: this.at };
this.at = undefined;
this.state = State.TOP;
return action;
}
token_byte(token) {
if (token == LINE_END) {
this.state = State.TOP;
return;
}
const action = { type: Action.DATA, size: 1 };
const value = this.integer(token);
if (value == null) {
action.symbol = token;
} else {
if (value > 0xff)
console.error(`WARNING: Value ${token} is truncated`);
action.value = value;
}
return action;
}
token_word(token) {
if (token == LINE_END) {
this.state = State.TOP;
return;
}
const action = { type: Action.DATA, size: 4 };
const value = this.integer(token);
if (value == null) {
action.symbol = token;
} else {
if (value > 0xffffffff)
console.error(`WARNING: Value ${token} is truncated`);
action.value = value;
}
return action;
}
token_utf8(token) {
if (token == LINE_END) {
this.state = State.TOP;
return;
} else if (token.string == undefined) {
console.error(
`ERROR: Unexpected token ${token}, expected string`);
return;
}
const bytes = this.encoder.encode(token.string);
const action = { type: Action.DATA, size: bytes.length, bytes };
return action;
}
token_align(token) {
const action = { type: Action.ALIGN };
if (token == LINE_END) {
action.alignment = 4;
} else {
action.alignment = this.integer(token);
if (action.alignment == null) {
console.error(
`ERROR: Unexpected token ${token}, expected alignment`);
this.state = State.TOP;
return action;
}
}
this.state = State.TOP
return action;
}
token_def_name(token) {
if (token == LINE_END) {
console.error("ERROR: Unexpected end of line, expected name");
this.state = State.TOP;
return;
}
this.def_name = token;
this.state = State.DEF_VALUE;
}
token_def_value(token) {
if (token == LINE_END) {
console.error("ERROR: Unexpected end of line, expected value");
this.def_name = undefined;
this.state = State.TOP;
return;
}
const action = {
type: Action.DEF,
def: { name: this.def_name },
};
const value = this.integer(token);
if (value != null)
action.def.value = value;
else
action.def.symbol = token;
this.def_name = undefined;
this.state = State.TOP;
return action;
}
token_block_name(token) {
if (token == LINE_END) {
this.block.type = types["void"];
const action = { type: Action.ENTER, block: this.block };
this.state = State.TOP;
this.block = undefined;
return action;
} else {
this.block.label = token;
this.state = State.BLOCK_TYPE;
return;
}
}
token_block_type(token) {
if (token == LINE_END) {
this.block.type = types["void"];
} else {
this.block.type = types[token];
if (this.block.type == undefined) {
console.error(
`ERROR: Unexpected token ${token}, expected type`);
}
}
const action = { type: Action.ENTER, block: this.block };
this.state = State.TOP;
this.block = undefined;
return action;
}
token_type_name(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected end of line in .type, expected name");
this.state = State.TOP;
return;
}
this.type = { name: token, params: [] };
this.state = State.TYPE_PARAM;
}
token_type_param(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected end of line in .type, expected "
+ "parameter type");
this.type = undefined;
this.state = State.TOP;
return;
}
if (token == "result") {
this.type.results = [];
this.state = State.TYPE_RESULT;
return;
}
const type = types[token];
if (type == undefined) {
console.error(
`ERROR: Unexpected token ${token} in .type, expected `
+ "parameter type");
this.type = undefined;
this.state = State.TOP;
return;
}
this.type.params.push(type);
}
token_type_result(token) {
if (token == LINE_END) {
const action = { type: Action.TYPE, the_type: this.type };
this.type = undefined;
this.state = State.TOP;
return action;
}
const type = types[token];
if (type == undefined) {
console.error(
`ERROR: Unexpected token ${token} in .type, expected `
+ "result type");
this.type = undefined;
this.state = State.TOP;
return;
}
this.type.results.push(type);
}
token_table_name(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected end of line in .table, expected name");
this.state = State.TOP;
return;
}
this.table = { name: token };
this.state = State.TABLE_SIZE;
}
token_table_size(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected end of line in .table, expected size");
this.table = undefined;
this.state = State.TOP;
return;
}
const size = this.integer(token);
if (size == null) {
console.error(
`ERROR: Unexpected token ${token} in .table, expected size`);
this.table = undefined;
this.state = State.TOP;
return;
}
this.table.size = size;
const action = { type: Action.TABLE, table: this.table };
this.table = undefined;
this.state = State.TOP;
return action;
}
token_elem_table(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected end of line in .elem, expected "
+ "table name");
this.state = State.TOP;
return;
}
this.elem = { table: token };
this.state = State.ELEM_ELEM;
}
token_elem_elem(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected end of line in .elem, expected "
+ "element name");
this.state = State.TOP;
this.elem = undefined;
return;
}
this.elem.elem = token;
this.state = State.ELEM_LABEL;
}
token_elem_label(token) {
if (token != LINE_END)
this.elem.label = token;
const action = { type: Action.ELEM, elem: this.elem };
this.elem = undefined
this.state = State.TOP;
return action;
}
token_zero(token) {
if (token == LINE_END) {
console.error(
"ERROR: Unexpected newline in .zero, expected count")
this.state = State.TOP;
return;
}
const count = this.integer(token);
if (count == null) {
console.error(
`ERROR: Unexpected token ${token} in .zero, expected count`);
this.state = State.TOP;
return;
}
this.state = State.TOP;
return { type: Action.DATA, size: count, value: 0 }
}
mem_action() {
const action = {
type: Action.MEM,
mem: { [this.mem_name]: { ...this.mem } }
};
this.mem = undefined;
this.mem_name = undefined;
this.state = State.TOP;
return action;
}
*handle(src) {
let action;
for (const token of this.tokenizer.handle(src)) {
const handler = this.handlers[this.state];
if (handler == undefined) {
console.error(`ERROR: Unhandled state ${this.state}`);
this.state = State.TOP;
continue;
}
if (action = handler(token))
yield action;
}
}
}
const Section = Object.freeze({
TYPE: 0x01,
IMPORT: 0x02,
FUNC: 0x03,
TABLE: 0x04,
MEM: 0x05,
GLOBAL: 0x06,
EXPORT: 0x07,
ELEM: 0x09,
CODE: 0x0a,
DATA: 0x0b,
});
const Kind = Object.freeze({
FUNC: 0x00,
MEM: 0x02,
});
export class Assembler {
constructor() {
this.encoder = new TextEncoder("utf-8");
this.decoder = new TextDecoder("utf-8");
this.parser = new Parser(this.encoder);
this.handlers = {
[Action.APPEND]: (action) => this.action_append(action),
[Action.EXPORT]: (action) => this.action_export(action),
[Action.FUNC]: (action) => this.action_func(action),
[Action.RESULT]: (action) => this.action_result(action),
[Action.PARAM]: (action) => this.action_param(action),
[Action.SYMBOL]: (action) => this.action_symbol(action),
[Action.LOCAL]: (action) => this.action_local(action),
[Action.MEM]: (action) => this.action_mem(action),
[Action.IMPORT]: (action) => this.action_import(action),
[Action.GLOBAL]: (action) => this.action_global(action),
[Action.AT]: (action) => this.action_at(action),
[Action.DATA]: (action) => this.action_data(action),
[Action.ALIGN]: (action) => this.action_align(action),
[Action.DEF]: (action) => this.action_def(action),
[Action.LABEL]: (action) => this.action_label(action),
[Action.ENTER]: (action) => this.action_enter(action),
[Action.EXIT]: (action) => this.action_exit(action),
[Action.ELSE]: (action) => this.action_else(action),
[Action.TYPE]: (action) => this.action_type(action),
[Action.TABLE]: (action) => this.action_table(action),
[Action.ELEM]: (action) => this.action_elem(action),
};
this.exports = [];
this.funcs = {};
this.mems = {};
this.imports = [];
this.globals = {};
this.pos = { mem: 0, addr: 0 };
this.data = [];
this.defs = {};
this.blocks = [];
this.types = [];
this.type_bindings = {};
this.tables = {};
this.unresolved = [];
}
action_append(action) {
const code = action.opcode != undefined
? [ action.opcode ].flat()
: this.leb128(action.literal);
this.funcs[this.current_func].body.push(...code);
}
action_export(action) {
const index = Object.keys(this.funcs).indexOf(action.name);
this.exports[action.name] = { kind: Kind.FUNC, index };
}
action_func(action) {
this.funcs[action.name] = {
params: {},
results: [],
locals: {},
body: [],
}
this.current_func = action.name;
}
action_result(action) {
this.funcs[this.current_func].results.push(...action.results);
}
action_param(action) {
Object.assign(this.funcs[this.current_func].params, action.params);
}
action_local(action) {
Object.assign(this.funcs[this.current_func].locals, action.locals);
}
action_symbol(action) {
const func = this.funcs[this.current_func];
const value = this.lookup_block(action.symbol)
?? this.lookup_param(func, action.symbol)
?? this.lookup_local(func, action.symbol)
?? this.lookup_global(action.symbol)
?? this.lookup_table(action.symbol)
?? this.lookup_type(action.symbol)
?? this.lookup_func(action.symbol);
if (value == null) {
const def_value = this.lookup_def(action.symbol);
if (def_value == null) {
console.error(
`ERROR: Unable to resolve symbol ${action.symbol}`);
return;
}
func.body.push(...this.leb128(def_value));
} else {
func.body.push(...this.uleb128(value));
}
}
action_mem(action) {
Object.assign(this.mems, action.mem);
}
action_import(action) {
const mem = this.mems[action.import.name];
mem.imported = true;
this.imports.push({
mod: action.import.mod,
field: action.import.field,
kind: Kind.MEM,
flags: mem.flags,
init: mem.init,
max: mem.max,
})
}
action_global(action) {
Object.assign(this.globals, action.global);
}
action_at(action) {
const mem = Object.keys(this.mems).indexOf(action.at.mem);
if (mem == -1) {
console.error(`ERROR: No memory named ${action.at.mem}`);
return;
}
this.pos.mem = mem;
this.pos.addr = action.at.addr
?? this.lookup_def(action.at.addr_symbol);
this.data.push({ loc: { ...this.pos }, data: [] })
}
action_data(action) {
const data = this.data.at(-1).data;
let bytes;
if (action.bytes != undefined) {
bytes = action.bytes;
} else {
let value = action.value;
if (value == undefined) {
if (action.symbol == undefined) {
console.error("ERROR: Invalid data action", action);
return;
}
value = this.lookup_def(action.symbol);
if (value == undefined) {
this.unresolved.push({
type: "data",
size: action.size,
symbol: action.symbol,
target: data,
offset: data.length,
});
value = 0;
}
}
bytes = this.le(value, action.size);
}
data.push(...bytes);
this.pos.addr += action.size;
}
action_align(action) {
const alignment = action.alignment;
const data = this.data.at(-1).data;
while (this.pos.addr % alignment != 0) {
data.push(0);
++this.pos.addr;
}
}
action_def(action) {
const value = action.def.value
?? this.lookup_def(action.def.symbol);
this.defs[action.def.name] = value;
}
action_label(action) {
this.defs[action.name] = this.pos.addr;
}
action_enter(action) {
this.funcs[this.current_func].body.push(action.block.code);
this.funcs[this.current_func].body.push(action.block.type);
this.blocks.push(action.block.label);
}
action_exit(action) {
this.funcs[this.current_func].body.push(opcodes.end);
this.blocks.pop();
}
action_else(action) {
this.blocks.pop();
this.funcs[this.current_func].body.push(opcodes.else);
this.blocks.push(undefined);
}
action_type(action) {
const type = this.func_type(action.the_type);
const index = this.ensure_type(type);
this.type_bindings[action.the_type.name] = index;
}
action_table(action) {
this.tables[action.table.name] = {
size: action.table.size,
elems: [],
};
}
action_elem(action) {
const table = this.tables[action.elem.table];
const fn = Object.keys(this.funcs).indexOf(action.elem.elem);
if (fn == -1) {
console.error(`ERROR: ${action.elem.elem}: no such function`);
return;
}
const index = table.elems.push(fn) - 1;
if (action.elem.label)
this.defs[action.elem.label] = index;
}
push(chunk) {
const text = this.decoder.decode(chunk, { stream: true });
for (const action of this.parser.handle(text)) {
const handler = this.handlers[action.type];
if (handler == undefined)
console.error("ERROR: Unhandled action", action);
else
handler(action);
}
}
lookup_block(symbol) {
const index = this.blocks.toReversed().indexOf(symbol);
return index == -1 ? null : index;
}
lookup_param(func, symbol) {
const index = Object.keys(func.params).indexOf(symbol);
return index == -1 ? null : index;
}
lookup_local(func, symbol) {
const param_count = Object.entries(func.params).length;
const index = Object.keys(func.locals).indexOf(symbol);
return index == -1 ? null : param_count + index;
}
lookup_global(symbol) {
const index = Object.keys(this.globals).indexOf(symbol);
return index == -1 ? null : index;
}
lookup_table(symbol) {
const index = Object.keys(this.tables).indexOf(symbol);
return index == -1 ? null : index;
}
lookup_type(symbol) {
return this.type_bindings[symbol];
}
lookup_func(symbol) {
const index = Object.keys(this.funcs).indexOf(symbol);
return index == -1 ? null : index;
}
lookup_def(symbol) {
return this.defs[symbol];
}
le(value, count) {
const bytes = []
while (value != 0) {
bytes.push(value & 0xff);
value >>>= 8;
}
if (count != undefined) {
while (bytes.length < count)
bytes.push(0);
}
return bytes;
}
leb128(x) {
const bytes = [];
while (true) {
const b = x & 0x7f;
x >>= 7;
if (x == 0 && (b & 0x40) == 0 || x == -1 && (b & 0x40) != 0) {
bytes.push(b);
return bytes;
}
bytes.push(b | 0x80);
}
}
uleb128(x) {
const bytes = [];
while (true) {
const b = x & 0x7f;
x >>>= 7;
if (x == 0) {
bytes.push(b);
return bytes;
}
bytes.push(b | 0x80);
}
return bytes;
}
wasm_section_type() {
if (this.types.length == 0) return null;
return [ this.types.length ].concat(...this.types);
}
wasm_section_import() {
if (this.imports.length == 0)
return null;
const contents = this.imports.map((imp) => {
const mod_utf8 = this.encoder.encode(imp.mod);
const field_utf8 = this.encoder.encode(imp.field);
return [
mod_utf8.length,
...mod_utf8,
field_utf8.length,
...field_utf8,
imp.kind,
...this.mem_wasm(imp),
];
});
return [ this.imports.length ].concat(...contents);
}
wasm_section_func() {
const types = Object.values(this.funcs).map(({type}) => type);
const count = types.length;
if (count == 0) return null;
return [ count, ...types ];
}
wasm_section_table() {
const sizes = Object.values(this.tables).map(({size}) => size);
if (sizes.length == 0) return null;
const contents = sizes.map((size) => [
types.funcref,
0x00,
this.uleb128(size),
]);
return [ sizes.length, contents ].flat(Infinity)
}
wasm_section_mem() {
const mems = Object.values(this.mems).filter(
({imported}) => !imported);
if (mems.length == 0)
return null;
const contents = mems.map((mem) => this.mem_wasm(mem));
return [ mems.length ].concat(...contents);
}
wasm_section_global() {
const globals = Object.values(this.globals);
if (globals.length == 0)
return null;
const contents = globals.map(({ type, init }) => [
type,
1,
const_opcodes[type],
...this.leb128(init),
opcodes["end"],
]);
return [ globals.length ].concat(...contents);
}
wasm_section_export() {
const exports = Object.entries(this.exports);
if (exports.length == 0) return null;
const contents = exports.map(([ name, { kind, index }]) => {
const name_utf8 = this.encoder.encode(name);
return [
name_utf8.length,
...name_utf8,
kind,
index,
];
});
return [ exports.length ].concat(...contents);
}
wasm_section_elem() {
const table_elems = Object.values(this.tables).map(
({elems}) => elems);
const count = table_elems.flat().length;
if (count == 0) return null;
const contents = table_elems.flatMap((elems, table) =>
elems.flatMap((fn, index) => [
table == 0 ? 0 : [ 2, table ],
opcodes["i32.const"],
index,
opcodes["end"],
1,
fn,
])
);
return [ count, contents ].flat();
}
wasm_section_code() {
const funcs = Object.values(this.funcs);
if (funcs.length == 0) return null;
const contents = funcs.map(({ body, locals }) => {
const local_types = Object.values(locals);
const local_count = local_types.length;
if (local_count == 0) {
const full_body = [ 0, body, opcodes.end ].flat()
return [ full_body.length, full_body ].flat();
} else {
const groups = this.group(local_types);
const full_body = [
groups.length,
...groups.flat(),
body,
opcodes.end,
].flat();
return [ full_body.length, full_body ].flat();
}
});
return [ contents.length, contents ].flat(Infinity);
}
wasm_section_data() {
if (this.data.length == 0) return null;
const contents = this.data.map(({ loc, data }) => {
return [
...(loc.mem == 0 ? [ 0 ] : [ 2, loc.mem ]),
opcodes["i32.const"],
...this.leb128(loc.addr),
opcodes["end"],
...this.uleb128(data.length),
...data,
]
});
return [ contents.length, contents ].flat(Infinity);
}
wasm() {
this.resolve_refs();
this.resolve_func_types();
const template = [
[ Section.TYPE, () => this.wasm_section_type() ],
[ Section.IMPORT, () => this.wasm_section_import() ],
[ Section.FUNC, () => this.wasm_section_func() ],
[ Section.TABLE, () => this.wasm_section_table() ],
[ Section.MEM, () => this.wasm_section_mem() ],
[ Section.GLOBAL, () => this.wasm_section_global() ],
[ Section.EXPORT, () => this.wasm_section_export() ],
[ Section.ELEM, () => this.wasm_section_elem() ],
[ Section.CODE, () => this.wasm_section_code() ],
[ Section.DATA, () => this.wasm_section_data() ],
];
const sections = template.map(([ code, generator ]) => {
const body = generator();
if (body == null)
return [];
return [ code, this.uleb128(body.length), body ];
});
return new Uint8Array([ HEADER, sections ].flat(Infinity));
}
mem_wasm({ flags, init, max }) {
if (flags & mem_flags.max)
return [ flags, init, max ];
else
return [ flags, init ];
}
func_type({ params, results }) {
const param_types = params.length == undefined
? Object.values(params)
: params;
return [
types["func"],
param_types.length,
...param_types,
results.length,
...results,
];
}
array_eq(a, b) {
return a.length == b.length && a.every((x, i) => x == b[i]);
}
ensure_type(type) {
const index = this.types.findIndex((t) => this.array_eq(type, t));
return index != -1 ? index : this.types.push(type) - 1;
}
resolve_func_types() {
for (const func of Object.values(this.funcs))
func.type = this.ensure_type(this.func_type(func));
}
group(array) {
return array.reduce((acc, val) => {
const last = acc.at(-1);
if (last != undefined && last[1] == val)
++last[0]
else
acc.push([1, val]);
return acc;
}, []);
}
resolve_refs() {
const failed = [];
for (const ref of this.unresolved) {
if (ref.type != "data") {
console.error(
`ERROR: Unsupported ref type ${ref.type} for `
+ `symbol ${ref.symbol}`
);
failed.push(ref.symbol);
continue;
}
const value = this.defs[ref.symbol];
if (value == undefined) {
failed.push(ref.symbol);
continue;
}
const bytes = this.le(value, ref.size);
ref.target.splice(ref.offset, ref.size, ...bytes);
}
if (failed.length != 0) {
const failed_str = failed.join(" ");
console.error(`ERROR: Unable to resolve refs: ${failed_str}`);
}
}
}