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elk.c
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// Copyright (c) 2013-2021 Cesanta Software Limited
// All rights reserved
//
// This software is dual-licensed: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License version 3 as
// published by the Free Software Foundation. For the terms of this
// license, see http://www.fsf.org/licensing/licenses/agpl-3.0.html
//
// You are free to use this software under the terms of the GNU General
// Public License, but WITHOUT ANY WARRANTY; without even the implied
// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU General Public License for more details.
//
// Alternatively, you can license this software under a commercial
// license, please contact us at https://cesanta.com/contact.html
#if defined(ARDUINO_AVR_NANO) || defined(ARDUINO_AVR_PRO) || \
defined(ARDUINO_AVR_UNO)
#define JS_NOCB
#define NDEBUG
#endif
#include <assert.h>
#include <inttypes.h>
#include <math.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "elk.h"
#ifndef JS_EXPR_MAX
#define JS_EXPR_MAX 20
#endif
typedef uint32_t jsoff_t;
struct js {
const char *code; // Currently parsed code snippet
char errmsg[36]; // Error message placeholder
uint8_t tok; // Last parsed token value
uint8_t flags; // Execution flags, see F_* enum below
uint16_t lev; // Recursion level
jsoff_t clen; // Code snippet length
jsoff_t pos; // Current parsing position
jsoff_t toff; // Offset of the last parsed token
jsoff_t tlen; // Length of the last parsed token
jsval_t tval; // Holds last parsed numeric or string literal value
jsval_t scope; // Current scope
#define F_NOEXEC 1 // Parse code, but not execute
#define F_LOOP 2 // We're inside the loop
#define F_CALL 4 // We're inside a function call
#define F_BREAK 8 // Exit the loop
#define F_RETURN 16 // Return has been executed
uint8_t *mem; // Available JS memory
jsoff_t size; // Memory size
jsoff_t brk; // Current mem usage boundary
jsoff_t ncbs; // Number of FFI-ed C "userdata" callback pointers
};
// A JS memory stores diffenent entities: objects, properties, strings
// All entities are packed to the beginning of a buffer.
// The `brk` marks the end of the used memory:
//
// | entity1 | entity2| .... |entityN| unused memory | cbs |
// |---------|--------|------|-------|------------------------------|-----|
// js.mem js.brk js.size
//
// Each entity is 4-byte aligned, therefore 2 LSB bits store entity type.
// Object: 8 bytes: offset of the first property, offset of the upper obj
// Property: 8 bytes + val: 4 byte next prop, 4 byte key offs, N byte value
// String: 4xN bytes: 4 byte len << 2, 4byte-aligned 0-terminated data
//
// FFI userdata callback pointers "cbs" are placed past js.size. Since they
// are passed to the user's C code, they stay constant and are not GC-ed
#define MARK ~(((jsoff_t) ~0) >> 1) // Entity deletion marker
// clang-format off
enum {
TOK_ERR, TOK_EOF, TOK_IDENTIFIER, TOK_NUMBER, TOK_STRING,
TOK_SEMICOLON, TOK_LPAREN, TOK_RPAREN, TOK_LBRACE, TOK_RBRACE,
// Keyword tokens
TOK_BREAK = 50, TOK_CASE, TOK_CATCH, TOK_CLASS, TOK_CONST, TOK_CONTINUE,
TOK_DEFAULT, TOK_DELETE, TOK_DO, TOK_ELSE, TOK_FINALLY, TOK_FOR,
TOK_FUNC, TOK_IF, TOK_IN, TOK_INSTANCEOF, TOK_LET, TOK_NEW, TOK_RETURN,
TOK_SWITCH, TOK_THIS, TOK_THROW, TOK_TRY, TOK_VAR, TOK_VOID, TOK_WHILE,
TOK_WITH, TOK_YIELD, TOK_UNDEF, TOK_NULL, TOK_TRUE, TOK_FALSE,
// JS Operator tokens
TOK_DOT = 100, TOK_CALL, TOK_POSTINC, TOK_POSTDEC, TOK_NOT, TOK_NEG,
TOK_TYPEOF, TOK_UPLUS, TOK_UMINUS, TOK_EXP, TOK_MUL, TOK_DIV, TOK_REM,
TOK_PLUS, TOK_MINUS, TOK_SHL, TOK_SHR, TOK_ZSHR, TOK_LT, TOK_LE, TOK_GT,
TOK_GE, TOK_EQ, TOK_NE, TOK_AND, TOK_XOR, TOK_OR, TOK_LAND, TOK_LOR,
TOK_COLON, TOK_Q, TOK_ASSIGN, TOK_PLUS_ASSIGN, TOK_MINUS_ASSIGN,
TOK_MUL_ASSIGN, TOK_DIV_ASSIGN, TOK_REM_ASSIGN, TOK_SHL_ASSIGN,
TOK_SHR_ASSIGN, TOK_ZSHR_ASSIGN, TOK_AND_ASSIGN, TOK_XOR_ASSIGN,
TOK_OR_ASSIGN, TOK_COMMA,
};
enum {
// IMPORTANT: T_OBJ, T_PROP, T_STR must go first. That is required by the
// memory layout functions: memory entity types are encoded in the 2 bits,
// thus type values must be 0,1,2,3
T_OBJ, T_PROP, T_STR, T_UNDEF, T_NULL, T_NUM, T_BOOL, T_FUNC, T_CODEREF,
T_ERR
};
static const char *typestr(uint8_t t) {
const char *names[] = { "object", "prop", "string", "undefined", "null",
"number", "boolean", "function", "nan" };
return (t < sizeof(names) / sizeof(names[0])) ? names[t] : "??";
}
// Pack JS values into uin64_t, double nan, per IEEE 754
// 64bit "double": 1 bit sign, 11 bits exponent, 52 bits mantissa
//
// seeeeeee|eeeemmmm|mmmmmmmm|mmmmmmmm|mmmmmmmm|mmmmmmmm|mmmmmmmm|mmmmmmmm
// 11111111|11110000|00000000|00000000|00000000|00000000|00000000|00000000 inf
// 11111111|11111000|00000000|00000000|00000000|00000000|00000000|00000000 qnan
//
// 11111111|1111tttt|vvvvvvvv|vvvvvvvv|vvvvvvvv|vvvvvvvv|vvvvvvvv|vvvvvvvv
// NaN marker |type| 48-bit placeholder for values: pointers, strings
//
// On 64-bit platforms, pointers are really 48 bit only, so they can fit,
// provided they are sign extended
static jsval_t tov(double d) { union { double d; jsval_t v; } u = {d}; return u.v; }
static double tod(jsval_t v) { union { jsval_t v; double d; } u = {v}; return u.d; }
static jsval_t mkval(uint8_t type, unsigned long data) { return ((jsval_t) 0x7ff0 << 48) | ((jsval_t) (type) << 48) | data; }
static bool is_nan(jsval_t v) { return (v >> 52) == 0x7ff; }
static uint8_t vtype(jsval_t v) { return is_nan(v) ? ((v >> 48) & 15) : (uint8_t) T_NUM; }
static unsigned long vdata(jsval_t v) { return (unsigned long) (v & ~((jsval_t) 0x7fff << 48)); }
static jsval_t mkcoderef(jsval_t off, jsoff_t len) { return mkval(T_CODEREF, (off & 0xffffff) | ((len & 0xffffff) << 24)); }
static jsoff_t coderefoff(jsval_t v) { return v & 0xffffff; }
static jsoff_t codereflen(jsval_t v) { return (v >> 24) & 0xffffff; }
static uint8_t unhex(uint8_t c) { return (c >= '0' && c <= '9') ? c - '0' : (c >= 'a' && c <= 'f') ? c - 'W' : (c >= 'A' && c <= 'F') ? c - '7' : 0; }
static uint64_t unhexn(const uint8_t *s, int len) { uint64_t v = 0; for (int i = 0; i < len; i++) { if (i > 0) v <<= 4; v |= unhex(s[i]); } return v; }
static bool is_space(int c) { return c == ' ' || c == '\r' || c == '\n' || c == '\t' || c == '\f' || c == '\v'; }
static bool is_digit(int c) { return c >= '0' && c <= '9'; }
static bool is_xdigit(int c) { return is_digit(c) || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'); }
static bool is_alpha(int c) { return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); }
static bool is_ident_begin(int c) { return c == '_' || c == '$' || is_alpha(c); }
static bool is_ident_continue(int c) { return c == '_' || c == '$' || is_alpha(c) || is_digit(c); }
static bool is_err(jsval_t v) { return vtype(v) == T_ERR; }
static bool is_op(uint8_t tok) { return tok >= TOK_DOT; }
static bool is_unary(uint8_t tok) { return tok >= TOK_POSTINC && tok <= TOK_UMINUS; }
static bool is_right_assoc(uint8_t tok) { return (tok >= TOK_NOT && tok <= TOK_UMINUS) || (tok >= TOK_Q && tok <= TOK_OR_ASSIGN); }
static bool is_assign(uint8_t tok) { return (tok >= TOK_ASSIGN && tok <= TOK_OR_ASSIGN); }
static void saveoff(struct js *js, jsoff_t off, jsoff_t val) { memcpy(&js->mem[off], &val, sizeof(val)); }
static void saveval(struct js *js, jsoff_t off, jsval_t val) { memcpy(&js->mem[off], &val, sizeof(val)); }
static jsoff_t loadoff(struct js *js, jsoff_t off) { jsoff_t v = 0; assert(js->brk <= js->size); memcpy(&v, &js->mem[off], sizeof(v)); return v; }
static jsoff_t offtolen(jsoff_t off) { return (off >> 2) - 1; }
static jsoff_t vstrlen(struct js *js, jsval_t v) { return offtolen(loadoff(js, vdata(v))); }
static jsval_t loadval(struct js *js, jsoff_t off) { jsval_t v = 0; memcpy(&v, &js->mem[off], sizeof(v)); return v; }
static jsval_t upper(struct js *js, jsval_t scope) { return mkval(T_OBJ, loadoff(js, vdata(scope) + sizeof(jsoff_t))); }
static jsoff_t align32(jsoff_t v) { return ((v + 3) >> 2) << 2; }
// clang-format on
// Forward declarations of the private functions
static size_t tostr(struct js *js, jsval_t value, char *buf, size_t len);
static jsval_t js_expr(struct js *js, uint8_t etok, uint8_t etok2);
static jsval_t js_stmt(struct js *js, uint8_t etok);
static jsval_t do_op(struct js *, uint8_t op, jsval_t l, jsval_t r);
// Stringify JS object
static size_t strobj(struct js *js, jsval_t obj, char *buf, size_t len) {
size_t n = snprintf(buf, len, "%s", "{");
jsoff_t next = loadoff(js, vdata(obj)) & ~3; // Load first prop offset
while (next < js->brk && next != 0) { // Iterate over props
jsoff_t koff = loadoff(js, next + sizeof(next));
jsval_t val = loadval(js, next + sizeof(next) + sizeof(koff));
// printf("PROP %u, koff %u\n", next & ~3, koff);
n += snprintf(buf + n, len - n, "%s", n == 1 ? "" : ",");
n += tostr(js, mkval(T_STR, koff), buf + n, len - n);
n += snprintf(buf + n, len - n, "%s", ":");
n += tostr(js, val, buf + n, len - n);
next = loadoff(js, next) & ~3; // Load next prop offset
}
return n + snprintf(buf + n, len - n, "%s", "}");
}
// Stringify numeric JS value
static size_t strnum(jsval_t value, char *buf, size_t len) {
double dv = tod(value), iv;
const char *fmt = modf(dv, &iv) == 0.0 ? "%.17g" : "%g";
return snprintf(buf, len, fmt, dv);
}
// Return mem offset and length of the JS string
static jsoff_t vstr(struct js *js, jsval_t value, jsoff_t *len) {
jsoff_t off = vdata(value);
if (len) *len = offtolen(loadoff(js, off));
return off + sizeof(off);
}
// Stringify string JS value
static size_t strstring(struct js *js, jsval_t value, char *buf, size_t len) {
jsoff_t n, off = vstr(js, value, &n);
// printf("STRING: len %u, off %lu %zu\n", n, off - sizeof(off), len);
return snprintf(buf, len, "\"%.*s\"", (int) n, (char *) js->mem + off);
}
// Stringify JS function
static size_t strfunc(struct js *js, jsval_t value, char *buf, size_t len) {
jsoff_t n, off = vstr(js, value, &n), isjs = (js->mem[off] == '(');
char *p = (char *) &js->mem[off];
return isjs ? snprintf(buf, len, "function%.*s", (int) n, p) // JS function
: snprintf(buf, len, "\"%.*s\"", (int) n, p); // C function
}
static jsval_t js_err(struct js *js, const char *fmt, ...) {
va_list ap;
size_t n = snprintf(js->errmsg, sizeof(js->errmsg), "%s", "ERROR: ");
va_start(ap, fmt);
vsnprintf(js->errmsg + n, sizeof(js->errmsg) - n, fmt, ap);
va_end(ap);
js->errmsg[sizeof(js->errmsg) - 1] = '\0';
// printf("ERR: [%s]\n", js->errmsg);
js->pos = js->clen; // We're done.. Jump to the end of code
js->tok = TOK_EOF;
return mkval(T_ERR, 0);
}
// Stringify JS value into the given buffer
static size_t tostr(struct js *js, jsval_t value, char *buf, size_t len) {
// clang-format off
switch (vtype(value)) {
case T_UNDEF: return snprintf(buf, len, "%s", "undefined");
case T_NULL: return snprintf(buf, len, "%s", "null");
case T_BOOL: return snprintf(buf, len, "%s", vdata(value) & 1 ? "true" : "false");
case T_OBJ: return strobj(js, value, buf, len);
case T_STR: return strstring(js, value, buf, len);
case T_NUM: return strnum(value, buf, len);
case T_FUNC: return strfunc(js, value, buf, len);
default: return snprintf(buf, len, "VTYPE%d", vtype(value));
}
// clang-format on
}
// Stringify JS value into a free JS memory block
const char *js_str(struct js *js, jsval_t value) {
// Leave jsoff_t placeholder between js->brk and a stringify buffer,
// in case if next step is convert it into a JS variable
char *buf = (char *) &js->mem[js->brk + sizeof(jsoff_t)];
size_t len, available = js->size - js->brk - sizeof(jsoff_t);
if (is_err(value)) return js->errmsg;
if (js->brk + sizeof(jsoff_t) >= js->size) return "";
len = tostr(js, value, buf, available);
js_mkstr(js, NULL, len);
// printf("JSSTR: %d [%s]\n", vtype(value), buf);
return buf;
}
static bool js_truthy(struct js *js, jsval_t v) {
uint8_t t = vtype(v);
return (t == T_BOOL && vdata(v) != 0) || (t == T_NUM && tod(v) != 0.0) ||
(t == T_OBJ || t == T_FUNC) || (t == T_STR && vstrlen(js, v) > 0);
}
static jsoff_t js_alloc(struct js *js, size_t size) {
jsoff_t ofs = js->brk;
size = align32((jsoff_t) size); // 4-byte align, (n + k - 1) / k * k
if (js->brk + size > js->size) return ~(jsoff_t) 0;
js->brk += (jsoff_t) size;
return ofs;
}
static jsval_t mkentity(struct js *js, jsoff_t b, const void *buf, size_t len) {
jsoff_t ofs = js_alloc(js, len + sizeof(b));
if (ofs == (jsoff_t) ~0) return js_err(js, "oom");
memcpy(&js->mem[ofs], &b, sizeof(b));
// Using memmove - in case we're stringifying data from the free JS mem
if (buf != NULL) memmove(&js->mem[ofs + sizeof(b)], buf, len);
if ((b & 3) == T_STR) js->mem[ofs + sizeof(b) + len - 1] = 0; // 0-terminate
// printf("MKE: %u @ %u type %d\n", js->brk - ofs, ofs, b & 3);
return mkval(b & 3, ofs);
}
jsval_t js_mkstr(struct js *js, const void *ptr, size_t len) {
// printf("MKSTR: [%.*s] -> off %u\n", (int) len, (char *) ptr, js->brk);
return mkentity(js, (jsoff_t) (((len + 1) << 2) | T_STR), ptr, len + 1);
}
static jsval_t mkobj(struct js *js, jsoff_t parent) {
return mkentity(js, 0 | T_OBJ, &parent, sizeof(parent));
}
static jsval_t setprop(struct js *js, jsval_t obj, jsval_t k, jsval_t v) {
jsoff_t koff = vdata(k); // Key offset
jsoff_t b, head = vdata(obj); // Property list head
char buf[sizeof(koff) + sizeof(v)]; // Property memory layout
memcpy(&b, &js->mem[head], sizeof(b)); // Load current 1st prop offset
memcpy(buf, &koff, sizeof(koff)); // Initialize prop data: copy key
memcpy(buf + sizeof(koff), &v, sizeof(v)); // Copy value
jsoff_t brk = js->brk | T_OBJ; // New prop offset
memcpy(&js->mem[head], &brk, sizeof(brk)); // Repoint head to the new prop
// printf("PROP: %u -> %u\n", b, brk);
return mkentity(js, (b & ~3) | T_PROP, buf, sizeof(buf)); // Create new prop
}
// Return T_OBJ/T_PROP/T_STR entity size based on the first word in memory
static inline jsoff_t esize(jsoff_t w) {
// clang-format off
switch (w & 3) {
case T_OBJ: return sizeof(jsoff_t) + sizeof(jsoff_t);
case T_PROP: return sizeof(jsoff_t) + sizeof(jsoff_t) + sizeof(jsval_t);
case T_STR: return sizeof(jsoff_t) + align32(w >> 2);
default: return (jsoff_t) ~0;
}
// clang-format on
}
static bool is_mem_entity(uint8_t t) {
return t == T_OBJ || t == T_PROP || t == T_STR || t == T_FUNC;
}
static void js_fixup_offsets(struct js *js, jsoff_t start, jsoff_t size) {
for (jsoff_t n, v, off = 0; off < js->brk; off += n) { // start from 0!
v = loadoff(js, off);
n = esize(v & ~MARK);
if (v & MARK) continue; // To be deleted, don't bother
if ((v & 3) != T_OBJ && (v & 3) != T_PROP) continue;
if (v > start) saveoff(js, off, v - size);
if ((v & 3) == T_PROP) {
jsoff_t koff = loadoff(js, off + sizeof(off));
if (koff > start) saveoff(js, off + sizeof(off), koff - size);
jsval_t val = loadval(js, off + sizeof(off) + sizeof(off));
if (is_mem_entity(vtype(val)) && vdata(val) > start) {
// printf("MV %u %lu -> %lu\n", off, vdata(val), vdata(val) - size);
saveval(js, off + sizeof(off) + sizeof(off),
mkval(vtype(val), vdata(val) - size));
}
}
}
for (jsoff_t i = 0; i < js->ncbs; i++) {
jsoff_t base = js->size + i * 3 * sizeof(jsoff_t) + sizeof(jsoff_t);
jsoff_t o1 = loadoff(js, base), o2 = loadoff(js, base + sizeof(o1));
if (o1 > start) saveoff(js, base, o1 - size);
if (o2 > start) saveoff(js, base + sizeof(jsoff_t), o2 - size);
}
// Fixup js->scope
jsoff_t off = vdata(js->scope);
if (off > start) js->scope = mkval(T_OBJ, off - size);
}
static void js_delete_marked_entities(struct js *js) {
for (jsoff_t n, v, off = 0; off < js->brk; off += n) {
v = loadoff(js, off);
n = esize(v & ~MARK);
if (v & MARK) { // This entity is marked for deletion, remove it
// printf("DEL: %4u %d %x\n", off, v & 3, n);
// assert(off + n <= js->brk);
js_fixup_offsets(js, off, n);
memmove(&js->mem[off], &js->mem[off + n], js->brk - off - n);
js->brk -= n; // Shrink brk boundary by the size of deleted entity
n = 0; // We shifted data, next iteration stay on this offset
}
}
}
static void js_mark_all_entities_for_deletion(struct js *js) {
for (jsoff_t v, off = 0; off < js->brk; off += esize(v)) {
v = loadoff(js, off);
saveoff(js, off, v | MARK);
}
}
static jsoff_t js_unmark_entity(struct js *js, jsoff_t off) {
jsoff_t v = loadoff(js, off);
if (v & MARK) {
saveoff(js, off, v & ~MARK);
// printf("UNMARK %5u\n", off);
if ((v & 3) == T_OBJ) js_unmark_entity(js, v & ~(MARK | 3));
if ((v & 3) == T_PROP) {
js_unmark_entity(js, v & ~(MARK | 3)); // Unmark next prop
js_unmark_entity(js, loadoff(js, off + sizeof(off))); // Unmark key
jsval_t val = loadval(js, off + sizeof(off) + sizeof(off));
if (is_mem_entity(vtype(val))) js_unmark_entity(js, vdata(val));
}
}
return v & ~(MARK | 3);
}
static void js_unmark_used_entities(struct js *js) {
for (jsval_t scope = js->scope;;) {
js_unmark_entity(js, vdata(scope));
jsoff_t off = loadoff(js, vdata(scope)) & ~3;
while (off < js->brk && off != 0) off = js_unmark_entity(js, off);
if (vdata(scope) == 0) break; // Last (global) scope processed
scope = upper(js, scope);
}
for (jsoff_t i = 0; i < js->ncbs; i++) {
jsoff_t base = js->size + i * 3 * sizeof(jsoff_t) + sizeof(jsoff_t);
js_unmark_entity(js, loadoff(js, base));
js_unmark_entity(js, loadoff(js, base + sizeof(jsoff_t)));
}
}
void js_gc(struct js *js) {
// printf("GC RUN\n");
js_mark_all_entities_for_deletion(js);
js_unmark_used_entities(js);
js_delete_marked_entities(js);
}
// Skip whitespaces and comments
static jsoff_t skiptonext(const char *code, jsoff_t len, jsoff_t n) {
// printf("SKIP: [%.*s]\n", len - n, &code[n]);
while (n < len) {
if (is_space(code[n])) {
n++;
} else if (n + 1 < len && code[n] == '/' && code[n + 1] == '/') {
for (n += 2; n < len && code[n] != '\n';) n++;
} else if (n + 3 < len && code[n] == '/' && code[n + 1] == '*') {
for (n += 4; n < len && (code[n - 2] != '*' || code[n - 1] != '/');) n++;
} else {
break;
}
}
return n;
}
static bool streq(const char *buf, size_t len, const char *p, size_t n) {
return n == len && memcmp(buf, p, len) == 0;
}
static uint8_t parsekeyword(const char *buf, size_t len) {
// clang-format off
switch (buf[0]) {
case 'b': if (streq("break", 5, buf, len)) return TOK_BREAK; break;
case 'c': if (streq("class", 5, buf, len)) return TOK_CLASS; if (streq("case", 4, buf, len)) return TOK_CASE; if (streq("catch", 5, buf, len)) return TOK_CATCH; if (streq("const", 5, buf, len)) return TOK_CONST; if (streq("continue", 8, buf, len)) return TOK_CONTINUE; break;
case 'd': if (streq("do", 2, buf, len)) return TOK_DO; if (streq("default", 7, buf, len)) return TOK_DEFAULT; break; // if (streq("delete", 6, buf, len)) return TOK_DELETE; break;
case 'e': if (streq("else", 4, buf, len)) return TOK_ELSE; break;
case 'f': if (streq("for", 3, buf, len)) return TOK_FOR; if (streq("function", 8, buf, len)) return TOK_FUNC; if (streq("finally", 7, buf, len)) return TOK_FINALLY; if (streq("false", 5, buf, len)) return TOK_FALSE; break;
case 'i': if (streq("if", 2, buf, len)) return TOK_IF; if (streq("in", 2, buf, len)) return TOK_IN; if (streq("instanceof", 10, buf, len)) return TOK_INSTANCEOF; break;
case 'l': if (streq("let", 3, buf, len)) return TOK_LET; break;
case 'n': if (streq("new", 3, buf, len)) return TOK_NEW; if (streq("null", 4, buf, len)) return TOK_NULL; break;
case 'r': if (streq("return", 6, buf, len)) return TOK_RETURN; break;
case 's': if (streq("switch", 6, buf, len)) return TOK_SWITCH; break;
case 't': if (streq("try", 3, buf, len)) return TOK_TRY; if (streq("this", 4, buf, len)) return TOK_THIS; if (streq("throw", 5, buf, len)) return TOK_THROW; if (streq("true", 4, buf, len)) return TOK_TRUE; if (streq("typeof", 6, buf, len)) return TOK_TYPEOF; break;
case 'u': if (streq("undefined", 9, buf, len)) return TOK_UNDEF; break;
case 'v': if (streq("var", 3, buf, len)) return TOK_VAR; if (streq("void", 4, buf, len)) return TOK_VOID; break;
case 'w': if (streq("while", 5, buf, len)) return TOK_WHILE; if (streq("with", 4, buf, len)) return TOK_WITH; break;
case 'y': if (streq("yield", 5, buf, len)) return TOK_YIELD; break;
}
// clang-format on
return TOK_IDENTIFIER;
}
static uint8_t parseident(const char *buf, jsoff_t len, jsoff_t *tlen) {
if (is_ident_begin(buf[0])) {
while (*tlen < len && is_ident_continue(buf[*tlen])) (*tlen)++;
return parsekeyword(buf, *tlen);
}
return TOK_ERR;
}
static uint8_t nexttok(struct js *js) {
js->tok = TOK_ERR;
js->toff = js->pos = skiptonext(js->code, js->clen, js->pos);
js->tlen = 0;
const char *buf = js->code + js->toff;
// clang-format off
if (js->toff >= js->clen) { js->tok = TOK_EOF; return js->tok; }
#define TOK(T, LEN) { js->tok = T; js->tlen = (LEN); break; }
#define LOOK(OFS, CH) js->toff + OFS < js->clen && buf[OFS] == CH
switch (buf[0]) {
case '?': TOK(TOK_Q, 1);
case ':': TOK(TOK_COLON, 1);
case '(': TOK(TOK_LPAREN, 1);
case ')': TOK(TOK_RPAREN, 1);
case '{': TOK(TOK_LBRACE, 1);
case '}': TOK(TOK_RBRACE, 1);
case ';': TOK(TOK_SEMICOLON, 1);
case ',': TOK(TOK_COMMA, 1);
case '!': if (LOOK(1, '=') && LOOK(2, '=')) TOK(TOK_NE, 3); TOK(TOK_NOT, 1);
case '.': TOK(TOK_DOT, 1);
case '~': TOK(TOK_NEG, 1);
case '-': if (LOOK(1, '-')) TOK(TOK_POSTDEC, 2); if (LOOK(1, '=')) TOK(TOK_MINUS_ASSIGN, 2); TOK(TOK_MINUS, 1);
case '+': if (LOOK(1, '+')) TOK(TOK_POSTINC, 2); if (LOOK(1, '=')) TOK(TOK_PLUS_ASSIGN, 2); TOK(TOK_PLUS, 1);
case '*': if (LOOK(1, '*')) TOK(TOK_EXP, 2); if (LOOK(1, '=')) TOK(TOK_MUL_ASSIGN, 2); TOK(TOK_MUL, 1);
case '/': if (LOOK(1, '=')) TOK(TOK_DIV_ASSIGN, 2); TOK(TOK_DIV, 1);
case '%': if (LOOK(1, '=')) TOK(TOK_REM_ASSIGN, 2); TOK(TOK_REM, 1);
case '&': if (LOOK(1, '&')) TOK(TOK_LAND, 2); if (LOOK(1, '=')) TOK(TOK_AND_ASSIGN, 2); TOK(TOK_AND, 1);
case '|': if (LOOK(1, '|')) TOK(TOK_LOR, 2); if (LOOK(1, '=')) TOK(TOK_OR_ASSIGN, 2); TOK(TOK_OR, 1);
case '=': if (LOOK(1, '=') && LOOK(2, '=')) TOK(TOK_EQ, 3); TOK(TOK_ASSIGN, 1);
case '<': if (LOOK(1, '<') && LOOK(2, '=')) TOK(TOK_SHL_ASSIGN, 3); if (LOOK(1, '<')) TOK(TOK_SHL, 2); if (LOOK(1, '=')) TOK(TOK_LE, 2); TOK(TOK_LT, 1);
case '>': if (LOOK(1, '>') && LOOK(2, '=')) TOK(TOK_SHR_ASSIGN, 3); if (LOOK(1, '>')) TOK(TOK_SHR, 2); if (LOOK(1, '=')) TOK(TOK_GE, 2); TOK(TOK_GT, 1);
case '^': if (LOOK(1, '=')) TOK(TOK_XOR_ASSIGN, 2); TOK(TOK_XOR, 1);
case '"': case '\'':
js->tlen++;
while (js->toff + js->tlen < js->clen && buf[js->tlen] != buf[0]) {
uint8_t increment = 1;
if (buf[js->tlen] == '\\') {
if (js->toff + js->tlen + 2 > js->clen) break;
increment = 2;
if (buf[js->tlen + 1] == 'x') {
if (js->toff + js->tlen + 4 > js->clen) break;
increment = 4;
}
}
js->tlen += increment;
}
if (buf[0] == buf[js->tlen]) js->tok = TOK_STRING, js->tlen++;
break;
case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': {
char *end;
js->tval = tov(strtod(buf, &end)); // TODO(lsm): protect against OOB access
TOK(TOK_NUMBER, (jsoff_t) (end - buf));
}
default: js->tok = parseident(buf, js->clen - js->toff, &js->tlen); break;
}
// clang-format on
js->pos = js->toff + js->tlen;
// printf("NEXT: %d [%.*s]\n", js->tok, (int) js->tlen, buf);
return js->tok;
}
static uint8_t lookahead(struct js *js) {
uint8_t tok = nexttok(js);
js->pos -= js->tlen;
return tok;
}
// Bubble sort operators by their priority. TOK_* enum is already sorted
static void sortops(uint8_t *ops, int nops, jsval_t *stk) {
uint8_t prios[] = {19, 19, 17, 17, 16, 16, 16, 16, 16, 15, 14, 14, 14, 13, 13,
12, 12, 12, 11, 11, 11, 11, 10, 10, 9, 8, 7, 6, 5, 4,
4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1};
// printf("PRIO: %d\n", prios[TOK_PLUS - TOK_DOT]);
for (bool done = false; done == false;) {
done = true;
for (int i = 0; i + 1 < nops; i++) {
uint8_t o1 = vdata(stk[ops[i]]) & 255, o2 = vdata(stk[ops[i + 1]]) & 255;
uint8_t a = prios[o1 - TOK_DOT], b = prios[o2 - TOK_DOT], tmp = ops[i];
bool swap = a < b;
if (o1 == o2 && is_right_assoc(o1) && ops[i] < ops[i + 1]) swap = 1;
if (swap) ops[i] = ops[i + 1], ops[i + 1] = tmp, done = false;
}
}
}
static void mkscope(struct js *js) {
assert((js->flags & F_NOEXEC) == 0);
jsoff_t prev = vdata(js->scope);
js->scope = mkobj(js, prev);
// printf("ENTER SCOPE %u, prev %u\n", (jsoff_t) vdata(js->scope), prev);
}
static void delscope(struct js *js) {
js->scope = upper(js, js->scope);
// printf("EXIT SCOPE %u\n", (jsoff_t) vdata(js->scope));
}
static jsval_t js_block(struct js *js, bool create_scope) {
jsval_t res = mkval(T_UNDEF, 0);
jsoff_t brk1 = js->brk;
if (create_scope) mkscope(js); // Enter new scope
jsoff_t brk2 = js->brk;
while (js->tok != TOK_EOF && js->tok != TOK_RBRACE) {
js->pos = skiptonext(js->code, js->clen, js->pos);
if (js->pos < js->clen && js->code[js->pos] == '}') break;
res = js_stmt(js, TOK_RBRACE);
// printf(" blstmt [%.*s]\n", js->pos - pos, &js->code[pos]);
}
if (js->pos < js->clen && js->code[js->pos] == '}') js->pos++;
// printf("BLOCKEND [%.*s]\n", js->pos - pos, &js->code[pos]);
if (create_scope) delscope(js); // Exit scope
if (js->brk == brk2) js->brk = brk1; // Fast scope GC
return res;
}
static jsval_t js_eval_nogc(struct js *js, const char *buf, jsoff_t len) {
jsval_t res = mkval(T_UNDEF, 0);
js->tok = TOK_ERR;
js->code = buf;
js->clen = len;
js->pos = 0;
while (js->tok != TOK_EOF && !is_err(res)) {
js->pos = skiptonext(js->code, js->clen, js->pos);
if (js->pos >= js->clen) break;
res = js_stmt(js, TOK_SEMICOLON);
}
return res;
}
static jsval_t resolveprop(struct js *js, jsval_t v) {
if (vtype(v) != T_PROP) return v;
v = loadval(js, vdata(v) + sizeof(jsoff_t) + sizeof(jsoff_t));
return resolveprop(js, v);
}
static jsval_t assign(struct js *js, jsval_t lhs, jsval_t val) {
saveval(js, (vdata(lhs) & ~3) + sizeof(jsoff_t) + sizeof(jsoff_t), val);
return lhs;
}
static jsval_t do_assign_op(struct js *js, uint8_t op, jsval_t l, jsval_t r) {
uint8_t m[] = {TOK_PLUS, TOK_MINUS, TOK_MUL, TOK_DIV, TOK_REM, TOK_SHL,
TOK_SHR, TOK_ZSHR, TOK_AND, TOK_XOR, TOK_OR};
jsval_t res = do_op(js, m[op - TOK_PLUS_ASSIGN], resolveprop(js, l), r);
return assign(js, l, res);
}
// Seach for property in a single object
static jsoff_t lkp(struct js *js, jsval_t obj, const char *buf, size_t len) {
jsoff_t off = loadoff(js, vdata(obj)) & ~3; // Load first prop offset
// printf("LKP: %lu %u [%.*s]\n", vdata(obj), off, (int) len, buf);
while (off < js->brk && off != 0) { // Iterate over props
jsoff_t koff = loadoff(js, off + sizeof(off));
jsoff_t klen = (loadoff(js, koff) >> 2) - 1;
const char *p = (char *) &js->mem[koff + sizeof(koff)];
// printf(" %u %u[%.*s]\n", off, (int) klen, (int) klen, p);
if (streq(buf, len, p, klen)) return off; // Found !
off = loadoff(js, off) & ~3; // Load next prop offset
}
return 0; // Not found
}
// Lookup variable in the scope chain
static jsval_t lookup(struct js *js, const char *buf, size_t len) {
for (jsval_t scope = js->scope;;) {
jsoff_t off = lkp(js, scope, buf, len);
if (off != 0) return mkval(T_PROP, off);
if (vdata(scope) == 0) break;
scope = mkval(T_OBJ, loadoff(js, vdata(scope) + sizeof(jsoff_t)));
}
return js_err(js, "'%.*s' not found", (int) len, buf);
}
static jsval_t do_string_op(struct js *js, uint8_t op, jsval_t l, jsval_t r) {
jsoff_t n1, off1 = vstr(js, l, &n1);
jsoff_t n2, off2 = vstr(js, r, &n2);
if (op == TOK_PLUS) {
jsval_t res = js_mkstr(js, NULL, n1 + n2);
// printf("STRPLUS [%.*s] [%.*s]\n", (int) n1, &js->mem[off1], (int) n2,
// &js->mem[off2]);
if (vtype(res) == T_STR) {
jsoff_t n, off = vstr(js, res, &n);
memmove(&js->mem[off], &js->mem[off1], n1);
memmove(&js->mem[off + n1], &js->mem[off2], n2);
}
return res;
} else if (op == TOK_EQ) {
bool eq = n1 == n2 && memcmp(&js->mem[off1], &js->mem[off2], n1) == 0;
return mkval(T_BOOL, eq ? 1 : 0);
} else if (op == TOK_NE) {
bool eq = n1 == n2 && memcmp(&js->mem[off1], &js->mem[off2], n1) == 0;
return mkval(T_BOOL, eq ? 0 : 1);
} else {
return js_err(js, "bad str op");
}
}
static jsval_t do_dot_op(struct js *js, jsval_t l, jsval_t r) {
const char *ptr = (char *) &js->code[coderefoff(r)];
if (vtype(r) != T_CODEREF) return js_err(js, "ident expected");
// Handle stringvalue.length
if (vtype(l) == T_STR && streq(ptr, codereflen(r), "length", 6)) {
return tov(offtolen(loadoff(js, vdata(l))));
}
if (vtype(l) != T_OBJ) return js_err(js, "lookup in non-obj");
jsoff_t off = lkp(js, l, ptr, codereflen(r));
return off == 0 ? mkval(T_UNDEF, 0) : mkval(T_PROP, off);
}
static jsval_t js_call_params(struct js *js) {
jsoff_t pos = js->pos;
if (nexttok(js) == TOK_RPAREN)
return mkcoderef(pos, js->pos - pos - js->tlen);
js->pos -= js->tlen;
uint8_t flags = js->flags;
js->flags |= F_NOEXEC;
do {
jsval_t res = js_expr(js, TOK_COMMA, TOK_RPAREN);
if (is_err(res)) return res;
if (vdata(res) == 0) js->tok = TOK_ERR; // Expression had 0 tokens
} while (js->tok == TOK_COMMA);
js->flags = flags;
if (js->tok != TOK_RPAREN) return js_err(js, "parse error");
return mkcoderef(pos, js->pos - pos - js->tlen);
}
/////////////////////////////////////////////// C FFI implementation start
// clang-format off
#define MAX_FFI_ARGS 6
typedef uintptr_t jw_t;
typedef jsval_t (*w6w_t)(jw_t, jw_t, jw_t, jw_t, jw_t, jw_t);
union ffi_val { void *p; w6w_t fp; jw_t w; double d; uint64_t u64; };
//struct fficbparam { struct js *js; const char *decl; jsval_t jsfunc; };
static jsval_t call_js(struct js *js, const char *fn, int fnlen);
#ifndef JS_NOCB
static jw_t fficb(uintptr_t param, union ffi_val *args) {
jsoff_t size;
memcpy(&size, (char *) param, sizeof(size));
struct js *js = (struct js *) ((char *) param - size) - 1;
//printf("FFICB: js %p, param %p %u\n", js, (void *) param, size);
jsoff_t f1len, f1off = vstr(js, loadoff(js, size + sizeof(jsoff_t)), &f1len);
jsoff_t f2len, f2off = vstr(js, loadoff(js, size + 2 * sizeof(jsoff_t)), &f2len);
char buf[100], *decl = (char *) &js->mem[f1off];
jsoff_t n = 0, max = (jsoff_t) sizeof(buf);
//printf("F1: %u[%.*s]\n", f1len, (int) f1len, decl);
//printf("F2: %u[%.*s]\n", f2len, (int) f2len, &js->mem[f2off]);
while (f1len > 1 && decl[0] != '[') decl++, f1len--;
for (jsoff_t i = 0; i + 2 < f1len && decl[i + 2] != ']'; i++) {
if (n > 0) n += snprintf(buf + n, max - n, "%s", ",");
switch (decl[i + 2]) {
case 's': n += snprintf(buf + n, max - n, "'%s'", (char *) (uintptr_t) args[i].w); break;
case 'i': n += snprintf(buf + n, max - n, "%ld", (long) args[i].w); break;
case 'd': n += snprintf(buf + n, max - n, "%g", args[i].d); break;
default: n += snprintf(buf + n, max - n, "%s", "null"); break;
}
}
const char *code = js->code; // Save current parser state
jsoff_t clen = js->clen, pos = js->pos; // code, position and code length
js->code = buf; // Point parser to args
js->clen = n; // Set args length
js->pos = 0;
//jsoff_t fnlen, fnoff = vstr(js, cbp->jsfunc, &fnlen);
//printf("CALLING %s %p [%s] -> [%.*s]\n", decl, args, buf, (int) f2len, (char *) &js->mem[f2off]);
jsval_t res = call_js(js, (char *) &js->mem[f2off], f2len);
js->code = code, js->clen = clen, js->pos = pos; // Restore parser
//printf("FFICB->[%s]\n", js_str(js, res));
switch (decl[1]) {
case 'v': return mkval(T_UNDEF, 0);
case 'i': return (long) (is_nan(res) ? 0.0 : tod(res));
case 'd': case 'p': return (jw_t) tod(res);
case 's': if (vtype(res) == T_STR) return (jw_t) (js->mem + vstr(js, res, NULL));
}
return res;
}
static void ffiinitcbargs(union ffi_val *args, jw_t w1, jw_t w2, jw_t w3, jw_t w4, jw_t w5, jw_t w6) { args[0].w = w1; args[1].w = w2; args[2].w = w3; args[3].w = w4; args[4].w = w5; args[5].w = w6; }
static jsval_t fficb1(jw_t w1, jw_t w2, jw_t w3, jw_t w4, jw_t w5, jw_t w6) { union ffi_val args[6]; ffiinitcbargs(args, w1, w2, w3, w4, w5, w6); return fficb(w1, args); }
static jsval_t fficb2(jw_t w1, jw_t w2, jw_t w3, jw_t w4, jw_t w5, jw_t w6) { union ffi_val args[6]; ffiinitcbargs(args, w1, w2, w3, w4, w5, w6); return fficb(w2, args); }
static jsval_t fficb3(jw_t w1, jw_t w2, jw_t w3, jw_t w4, jw_t w5, jw_t w6) { union ffi_val args[6]; ffiinitcbargs(args, w1, w2, w3, w4, w5, w6); return fficb(w3, args); }
static jsval_t fficb4(jw_t w1, jw_t w2, jw_t w3, jw_t w4, jw_t w5, jw_t w6) { union ffi_val args[6]; ffiinitcbargs(args, w1, w2, w3, w4, w5, w6); return fficb(w4, args); }
static jsval_t fficb5(jw_t w1, jw_t w2, jw_t w3, jw_t w4, jw_t w5, jw_t w6) { union ffi_val args[6]; ffiinitcbargs(args, w1, w2, w3, w4, w5, w6); return fficb(w5, args); }
static jsval_t fficb6(jw_t w1, jw_t w2, jw_t w3, jw_t w4, jw_t w5, jw_t w6) { union ffi_val args[6]; ffiinitcbargs(args, w1, w2, w3, w4, w5, w6); return fficb(w6, args); }
// clang-format on
static w6w_t setfficb(const char *decl, int *idx) {
w6w_t res = 0, cbs[] = {fficb1, fficb2, fficb3, fficb4, fficb5, fficb6};
for (size_t i = 1; decl[i] != '\0' && decl[i] != ']'; i++) {
if (i >= (sizeof(cbs) / sizeof(cbs[0]))) break;
if (decl[i] == 'u') res = cbs[i - 1]; //, printf("SET CB %zu\n", i - 1);
(*idx)++;
}
(*idx) += 2;
return res;
}
#endif
// Call native C function
static jsval_t call_c(struct js *js, const char *fn, int fnlen, jsoff_t fnoff) {
union ffi_val args[MAX_FFI_ARGS], res;
jsoff_t cbp = 0;
int n = 0, i, type = fn[0] == 'd' ? 1 : 0;
for (i = 1; i < fnlen && fn[i] != '@' && n < MAX_FFI_ARGS; i++) {
js->pos = skiptonext(js->code, js->clen, js->pos);
if (js->pos >= js->clen) return js_err(js, "bad arg %d", n + 1);
jsval_t v = resolveprop(js, js_expr(js, TOK_COMMA, TOK_RPAREN));
// printf(" arg %d[%c] -> %s\n", n, fn[i], js_str(js, v));
if (fn[i] == 'd' || (fn[i] == 'j' && sizeof(jsval_t) > sizeof(jw_t))) {
type |= 1 << (n + 1);
}
uint8_t t = vtype(v);
// clang-format off
switch (fn[i]) {
#ifndef JS_NOCB
case '[':
// Create a non-GC-able FFI callback parameter inside JS runtime memory,
// to make it live if C calls it after GC is performed. This param
// should be a `void *` that goes to C, and stays intact. We allocate
// it at the end of free memory block and never GC. It has 3 values:
// offset to the js->mem. Used by fficb() to obtain `struct js *` ptr
// offset of the caller func. Used to get C func signature
// offset of the cb func. Used to actually run JS callback
js->ncbs++;
js->size -= sizeof(jsoff_t) * 3;
cbp = js->size;
saveoff(js, cbp, cbp);
saveoff(js, cbp + sizeof(jsoff_t), fnoff);
saveoff(js, cbp + sizeof(jsoff_t) + sizeof(jsoff_t), vdata(v));
args[n++].p = (void *) setfficb(&fn[i + 1], &i);
//printf("CB PARAM SET: js %p, param %p %u\n", js, &js->mem[cbp], cbp);
break;
#endif
case 'd': if (t != T_NUM) return js_err(js, "bad arg %d", n + 1); args[n++].d = tod(v); break;
case 'b': if (t != T_BOOL) return js_err(js, "bad arg %d", n + 1); args[n++].w = vdata(v); break;
case 'i': if (t != T_NUM && t != T_BOOL) return js_err(js, "bad arg %d", n + 1); args[n++].w = t == T_BOOL ? (long) vdata(v) : (long) tod(v); break;
case 's': if (t != T_STR) return js_err(js, "bad arg %d", n + 1); args[n++].p = js->mem + vstr(js, v, NULL); break;
case 'p': if (t != T_NUM) return js_err(js, "bad arg %d", n + 1); args[n++].w = (jw_t) tod(v); break;
case 'j': args[n++].u64 = v; break;
case 'm': args[n++].p = js; break;
case 'u': args[n++].p = &js->mem[cbp]; break;
default: return js_err(js, "bad sig");
}
js->pos = skiptonext(js->code, js->clen, js->pos);
if (js->pos < js->clen && js->code[js->pos] == ',') js->pos++;
}
uintptr_t f = (uintptr_t) unhexn((uint8_t *) &fn[i + 1], fnlen - i - 1);
//printf(" type %d nargs %d addr %" PRIxPTR "\n", type, n, f);
if (js->pos != js->clen) return js_err(js, "num args");
if (fn[i] != '@') return js_err(js, "ffi");
if (f == 0) return js_err(js, "ffi");
#ifndef WIN32
#define __cdecl
#endif
switch (type) {
case 0: res.u64 = ((uint64_t(__cdecl*)(jw_t,jw_t,jw_t,jw_t,jw_t,jw_t)) f) (args[0].w, args[1].w, args[2].w, args[3].w, args[4].w, args[5].w); break;
case 1: res.d = ((double(__cdecl*)(jw_t,jw_t,jw_t,jw_t,jw_t,jw_t)) f) (args[0].w, args[1].w, args[2].w, args[3].w, args[4].w, args[5].w); break;
case 2: res.u64 = ((uint64_t(__cdecl*)(double,jw_t,jw_t,jw_t,jw_t,jw_t)) f) (args[0].d, args[1].w, args[2].w, args[3].w, args[4].w, args[5].w); break;
case 3: res.d = ((double(__cdecl*)(double,jw_t,jw_t,jw_t,jw_t,jw_t)) f) (args[0].d, args[1].w, args[2].w, args[3].w, args[4].w, args[5].w); break;
case 4: res.u64 = ((uint64_t(__cdecl*)(jw_t,double,jw_t,jw_t,jw_t,jw_t)) f) (args[0].w, args[1].d, args[2].w, args[3].w, args[4].w, args[5].w); break;
case 5: res.d = ((double(__cdecl*)(jw_t,double,jw_t,jw_t,jw_t,jw_t)) f) (args[0].w, args[1].d, args[2].w, args[3].w, args[4].w, args[5].w); break;
case 6: res.u64 = ((uint64_t(__cdecl*)(double,double,jw_t,jw_t,jw_t,jw_t)) f) (args[0].d, args[1].d, args[2].w, args[3].w, args[4].w, args[5].w); break;
case 7: res.d = ((double(__cdecl*)(double,double,jw_t,jw_t,jw_t,jw_t)) f)(args[0].d, args[1].d, args[2].w, args[3].w, args[4].w, args[5].w); break;
default: return js_err(js, "ffi");
}
//printf(" TYPE %d RES: %" PRIxPTR " %g %p\n", type, res.v, res.d, res.p);
// Import return value into JS
switch (fn[0]) {
case 'p': return tov(res.w);
case 'i': return tov((int) res.u64);
case 'd': return tov(res.d);
case 'b': return mkval(T_BOOL, res.w ? 1 : 0);
case 's': return js_mkstr(js, (char *) (intptr_t) res.w, strlen((char *) (intptr_t) res.w));
case 'v': return mkval(T_UNDEF, 0);
case 'j': return (jsval_t) res.u64;
}
// clang-format on
return js_err(js, "bad sig");
}
/////////////////////////////////////////////// C FFI implementation end
// Call JS function. 'fn' looks like this: "(a,b) { return a + b; }"
static jsval_t call_js(struct js *js, const char *fn, int fnlen) {
int fnpos = 1;
mkscope(js); // Create function call scope
// Loop over arguments list "(a, b)" and set scope variables
while (fnpos < fnlen) {
fnpos = skiptonext(fn, fnlen, fnpos); // Skip to the identifier
if (fnpos < fnlen && fn[fnpos] == ')') break; // Closing paren? break!
jsoff_t identlen = 0; // Identifier length
uint8_t tok = parseident(&fn[fnpos], fnlen - fnpos, &identlen);
if (tok != TOK_IDENTIFIER) break;
// Here we have argument name
// printf(" [%.*s] -> %u [%.*s] -> ", (int) identlen, &fn[fnpos], js->pos,
//(int) js->clen, js->code);
// Calculate argument's value.
js->pos = skiptonext(js->code, js->clen, js->pos);
jsval_t v = js->code[js->pos] == ')' ? mkval(T_UNDEF, 0)
: js_expr(js, TOK_COMMA, TOK_RPAREN);
// printf("[%s]\n", js_str(js, v));
// Set argument in the function scope
setprop(js, js->scope, js_mkstr(js, &fn[fnpos], identlen), v);
js->pos = skiptonext(js->code, js->clen, js->pos);
if (js->pos < js->clen && js->code[js->pos] == ',') js->pos++;
fnpos = skiptonext(fn, fnlen, fnpos + identlen); // Skip past identifier
if (fnpos < fnlen && fn[fnpos] == ',') fnpos++; // And skip comma
}
if (fnpos < fnlen && fn[fnpos] == ')') fnpos++; // Skip to the function body
fnpos = skiptonext(fn, fnlen, fnpos); // Up to the opening brace
if (fnpos < fnlen && fn[fnpos] == '{') fnpos++; // And skip the brace
jsoff_t n = fnlen - fnpos - 1; // Function code with stripped braces
// printf(" %d. calling, %u [%.*s]\n", js->flags, n, (int) n, &fn[fnpos]);
js->flags = F_CALL; // Mark we're in the function call
jsval_t res = js_eval_nogc(js, &fn[fnpos], n); // Call function, no GC
if (!(js->flags & F_RETURN)) res = mkval(T_UNDEF, 0); // Is return called?
delscope(js); // Delete call scope
return res;
}
static jsval_t do_call_op(struct js *js, jsval_t func, jsval_t args) {
if (vtype(func) != T_FUNC) return js_err(js, "calling non-function");
if (vtype(args) != T_CODEREF) return js_err(js, "bad call");
jsoff_t fnlen, fnoff = vstr(js, func, &fnlen);
const char *fn = (const char *) &js->mem[fnoff];
const char *code = js->code; // Save current parser state
jsoff_t clen = js->clen, pos = js->pos; // code, position and code length
js->code = &js->code[coderefoff(args)]; // Point parser to args
js->clen = codereflen(args); // Set args length
js->pos = skiptonext(js->code, js->clen, 0); // Skip to 1st arg
// printf("CALL [%.*s] -> %.*s\n", (int) js->clen, js->code, (int) fnlen, fn);
uint8_t tok = js->tok, flags = js->flags; // Save flags
jsval_t res = fn[0] != '(' ? call_c(js, fn, fnlen, fnoff - sizeof(jsoff_t))
: call_js(js, fn, fnlen);
// printf(" -> %s\n", js_str(js, res));
js->code = code, js->clen = clen, js->pos = pos; // Restore parser
js->flags = flags, js->tok = tok;
return res;
}
static jsval_t do_logical_or(struct js *js, jsval_t l, jsval_t r) {
if (js_truthy(js, l)) return mkval(T_BOOL, 1);
return mkval(T_BOOL, js_truthy(js, r) ? 1 : 0);
}
// clang-format off
static jsval_t do_op(struct js *js, uint8_t op, jsval_t lhs, jsval_t rhs) {
jsval_t l = resolveprop(js, lhs), r = resolveprop(js, rhs);
//printf("OP %d %d %d\n", op, vtype(lhs), vtype(r));
if (is_assign(op) && vtype(lhs) != T_PROP) return js_err(js, "bad lhs");
switch (op) {
case TOK_LAND: return mkval(T_BOOL, js_truthy(js, l) && js_truthy(js, r) ? 1 : 0);
case TOK_LOR: return do_logical_or(js, l, r);
case TOK_TYPEOF: return js_mkstr(js, typestr(vtype(r)), strlen(typestr(vtype(r))));
case TOK_CALL: return do_call_op(js, l, r);
case TOK_ASSIGN: return assign(js, lhs, r);
case TOK_POSTINC: { do_assign_op(js, TOK_PLUS_ASSIGN, lhs, tov(1)); return l; }
case TOK_POSTDEC: { do_assign_op(js, TOK_MINUS_ASSIGN, lhs, tov(1)); return l; }
case TOK_NOT: if (vtype(r) == T_BOOL) return mkval(T_BOOL, !vdata(r)); break;
}
if (is_assign(op)) return do_assign_op(js, op, lhs, r);
if (vtype(l) == T_STR && vtype(r) == T_STR) return do_string_op(js, op, l, r);
if (is_unary(op) && vtype(r) != T_NUM) return js_err(js, "type mismatch");
if (!is_unary(op) && op != TOK_DOT && (vtype(l) != T_NUM || vtype(r) != T_NUM)) return js_err(js, "type mismatch");
double a = tod(l), b = tod(r);
switch (op) {
case TOK_EXP: return tov(pow(a, b));
case TOK_DIV: return tod(r) == 0 ? js_err(js, "div by zero") : tov(a / b);
case TOK_REM: return tov(a - b * ((long) (a / b)));
case TOK_MUL: return tov(a * b);
case TOK_PLUS: return tov(a + b);
case TOK_MINUS: return tov(a - b);
case TOK_XOR: return tov((long) a ^ (long) b);
case TOK_AND: return tov((long) a & (long) b);
case TOK_OR: return tov((long) a | (long) b);
case TOK_UMINUS: return tov(-b);
case TOK_UPLUS: return r;
case TOK_NEG: return tov(~(long) b);
case TOK_NOT: return mkval(T_BOOL, b == 0);
case TOK_SHL: return tov((long) a << (long) b);
case TOK_SHR: return tov((long) a >> (long) b);
case TOK_DOT: return do_dot_op(js, l, r);
case TOK_EQ: return mkval(T_BOOL, (long) a == (long) b);
case TOK_NE: return mkval(T_BOOL, (long) a != (long) b);
case TOK_LT: return mkval(T_BOOL, a < b);
case TOK_LE: return mkval(T_BOOL, a <= b);
case TOK_GT: return mkval(T_BOOL, a > b);
case TOK_GE: return mkval(T_BOOL, a >= b);
default: return js_err(js, "unknown op %d", (int) op); // LCOV_EXCL_LINE
}
}
// clang-format on
static uint8_t getri(uint32_t mask, uint8_t ri) {
while (ri > 0 && (mask & (1 << ri))) ri--;
if (!(mask & (1 << ri))) ri++;
return ri;
}
static jsval_t js_str_literal(struct js *js) {
uint8_t *in = (uint8_t *) &js->code[js->toff];
uint8_t *out = &js->mem[js->brk + sizeof(jsoff_t)];
int n1 = 0, n2 = 0;
// printf("STR %u %lu %lu\n", js->brk, js->tlen, js->clen);
if (js->brk + sizeof(jsoff_t) + js->tlen > js->size) return js_err(js, "oom");
while (n2++ + 2 < (int) js->tlen) {
if (in[n2] == '\\') {
if (in[n2 + 1] == in[0]) {
out[n1++] = in[0];
} else if (in[n2 + 1] == 'n') {
out[n1++] = '\n';
} else if (in[n2 + 1] == 't') {
out[n1++] = '\t';
} else if (in[n2 + 1] == 'r') {
out[n1++] = '\r';
} else if (in[n2 + 1] == 'x' && is_xdigit(in[n2 + 2]) &&
is_xdigit(in[n2 + 3])) {
out[n1++] = unhex(in[n2 + 2]) << 4 | unhex(in[n2 + 3]);
n2 += 2;
} else {
return js_err(js, "bad str literal");
}
n2++;
} else {
out[n1++] = js->code[js->toff + n2];
}
}
return js_mkstr(js, NULL, n1);
}
static jsval_t js_obj_literal(struct js *js) {
uint8_t exe = !(js->flags & F_NOEXEC);
// printf("OLIT1\n");
jsval_t obj = exe ? mkobj(js, 0) : mkval(T_UNDEF, 0);
if (is_err(obj)) return obj;
while (nexttok(js) != TOK_RBRACE) {
if (js->tok != TOK_IDENTIFIER) return js_err(js, "parse error");
size_t koff = js->toff, klen = js->tlen;
if (nexttok(js) != TOK_COLON) return js_err(js, "parse error");
jsval_t val = js_expr(js, TOK_RBRACE, TOK_COMMA);
if (exe) {
// printf("XXXX [%s] scope: %lu\n", js_str(js, val), vdata(js->scope));
if (is_err(val)) return val;
jsval_t key = js_mkstr(js, js->code + koff, klen);
if (is_err(key)) return key;