/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│ │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│ ╞══════════════════════════════════════════════════════════════════════════════╡ │ Copyright 2022 Justine Alexandra Roberts Tunney │ │ │ │ Permission to use, copy, modify, and/or distribute this software for │ │ any purpose with or without fee is hereby granted, provided that the │ │ above copyright notice and this permission notice appear in all copies. │ │ │ │ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │ │ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │ │ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │ │ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │ │ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │ │ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │ │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │ │ PERFORMANCE OF THIS SOFTWARE. │ ╚─────────────────────────────────────────────────────────────────────────────*/ #include "libc/bits/bits.h" #include "libc/bits/likely.h" #include "libc/intrin/kprintf.h" #include "libc/log/log.h" #include "libc/str/tpenc.h" #include "libc/str/utf16.h" #include "third_party/double-conversion/wrapper.h" #include "third_party/lua/lauxlib.h" #include "third_party/lua/ltests.h" #include "third_party/lua/lua.h" struct Rc { int t; const char *p; }; static struct Rc Parse(struct lua_State *L, const char *p, const char *e) { long x; char w[4]; struct Rc r; const char *a; luaL_Buffer b; int A, B, C, D, c, d, i, u; for (a = p, d = +1; p < e;) { switch ((c = *p++ & 255)) { default: luaL_error(L, "illegal character\n"); return (struct Rc){-1, p}; case ' ': // spaces case '\n': case '\r': case '\t': a = p; break; case ',': // present in list and object a = p; break; case ':': // present only in object after key if (LUA_TSTRING != lua_type(L, -1)) { luaL_error(L, "unexpected ':'\n"); return (struct Rc){-1, p}; } a = p; break; case 'n': // null if (p + 3 <= e && READ32LE(p - 1) == READ32LE("null")) { lua_pushnil(L); return (struct Rc){1, p + 3}; } luaL_error(L, "expecting null\n"); return (struct Rc){-1, p}; case 't': // true if (p + 3 <= e && READ32LE(p - 1) == READ32LE("true")) { lua_pushboolean(L, true); return (struct Rc){1, p + 3}; } luaL_error(L, "expecting true\n"); return (struct Rc){-1, p}; case 'f': // false if (p + 4 <= e && READ32LE(p) == READ32LE("alse")) { lua_pushboolean(L, false); return (struct Rc){1, p + 4}; } luaL_error(L, "expecting false\n"); return (struct Rc){-1, p}; case '-': // negative d = -1; break; case '0': // zero or number if (p < e && *p == '.') { goto UseDubble; } lua_pushinteger(L, 0); return (struct Rc){1, p}; case '1' ... '9': // integer for (x = (c - '0') * d; p < e; ++p) { c = *p & 255; if (isdigit(c)) { if (__builtin_mul_overflow(x, 10, &x) || __builtin_add_overflow(x, (c - '0') * d, &x)) { goto UseDubble; } } else if (c == '.' || c == 'e' || c == 'E') { goto UseDubble; } else { break; } } lua_pushinteger(L, x); return (struct Rc){1, p}; UseDubble: // number lua_pushnumber(L, StringToDouble(a, e - a, &c)); return (struct Rc){1, a + c}; case '[': // Array lua_newtable(L); i = 0; do { r = Parse(L, p, e); p = r.p; if (r.t) { lua_rawseti(L, -2, i++ + 1); } } while (r.t); if (*(p - 1) != ']') { luaL_error(L, "invalid list\n"); return (struct Rc){-1, p}; } return (struct Rc){1, p}; case ']': case '}': return (struct Rc){0, p}; case '{': // Object lua_newtable(L); i = 0; do { r = Parse(L, p, e); p = r.p; if (r.t) { if (LUA_TSTRING != lua_type(L, -1)) { /* json keys can only be strings */ lua_settop(L, -2); break; } r = Parse(L, p, e); p = r.p; if (!r.t) { /* key provided but no value */ lua_settop(L, -2); luaL_error(L, "key provided but no value\n"); return (struct Rc){-1, p}; } lua_settable(L, -3); ++i; } } while (r.t); if (!i) { // we need this kludge so `{}` won't round-trip as `[]` lua_pushstring(L, "__json_object__"); lua_pushboolean(L, true); lua_settable(L, -3); } if (*(p - 1) != '}') { luaL_error(L, "invalid object\n"); return (struct Rc){-1, p}; } return (struct Rc){1, p}; case '"': // string luaL_buffinit(L, &b); while (p < e) { switch ((c = *p++ & 255)) { default: AddByte: luaL_addchar(&b, c); break; case '\\': if (p < e) { switch ((c = *p++ & 255)) { case '0': case 'x': luaL_error(L, "invalid escaped character\n"); return (struct Rc){-1, p}; case '"': case '/': case '\\': default: goto AddByte; case 'b': c = '\b'; goto AddByte; case 'f': c = '\f'; goto AddByte; case 'n': c = '\n'; goto AddByte; case 'r': c = '\r'; goto AddByte; case 't': c = '\t'; goto AddByte; case 'u': if (p + 4 <= e && // (A = kHexToInt[p[0] & 255]) != -1 && // (B = kHexToInt[p[1] & 255]) != -1 && // UCS-2 (C = kHexToInt[p[2] & 255]) != -1 && // (D = kHexToInt[p[3] & 255]) != -1) { // c = A << 12 | B << 8 | C << 4 | D; if (!IsSurrogate(c)) { p += 4; } else if (IsHighSurrogate(c)) { if (p + 4 + 6 <= e && // p[4] == '\\' && // p[5] == 'u' && // (A = kHexToInt[p[6] & 255]) != -1 && // UTF-16 (B = kHexToInt[p[7] & 255]) != -1 && // (C = kHexToInt[p[8] & 255]) != -1 && // (D = kHexToInt[p[9] & 255]) != -1) { // u = A << 12 | B << 8 | C << 4 | D; if (IsLowSurrogate(u)) { p += 4 + 6; c = MergeUtf16(c, u); } else { goto BadUnicode; } } else { goto BadUnicode; } } else { goto BadUnicode; } // UTF-8 if (c < 0x7f) { w[0] = c; i = 1; } else if (c <= 0x7ff) { w[0] = 0300 | (c >> 6); w[1] = 0200 | (c & 077); i = 2; } else if (c <= 0xffff) { if (UNLIKELY(IsSurrogate(c))) { ReplacementCharacter: c = 0xfffd; } w[0] = 0340 | (c >> 12); w[1] = 0200 | ((c >> 6) & 077); w[2] = 0200 | (c & 077); i = 3; } else if (~(c >> 18) & 007) { w[0] = 0360 | (c >> 18); w[1] = 0200 | ((c >> 12) & 077); w[2] = 0200 | ((c >> 6) & 077); w[3] = 0200 | (c & 077); i = 4; } else { goto ReplacementCharacter; } luaL_addlstring(&b, w, i); } else { BadUnicode: // Echo invalid \uXXXX sequences // Rather than corrupting UTF-8! luaL_addstring(&b, "\\u"); } break; } } break; case '"': goto FinishString; } } FinishString: luaL_pushresult(&b); return (struct Rc){1, p}; } } return (struct Rc){0, p}; } /** * Parses JSON data structure string into Lua data structure. * * This function returns the number of items pushed to the Lua stack, * which should be 1, unless no parseable JSON content was found, in * which case this will return 0. On error -1 is returned. There's * currently no error return condition. This function doesn't do JSON * validity enforcement. * * JSON UTF-16 strings are re-encoded as valid UTF-8. 64-bit integers * are supported. If an integer overflows during parsing, it'll be * converted to a floating-point number instead. Invalid surrogate * escape sequences in strings won't be decoded. * * A weird case exists when parsing empty objects. In order to let Lua * tell them apart from empty arrays, we insert a special key that's * ignored by our JSON serializer, called `[__json_object__]=true`. * * @param L is Lua interpreter state * @param p is input string * @param n is byte length of `p` or -1 for automatic strlen() * @return 1 if value was pushed, 0 on end, or -1 on error */ int DecodeJson(struct lua_State *L, const char *p, size_t n) { if (n == -1) n = p ? strlen(p) : 0; lua_checkstack(L, 128); return Parse(L, p, p + n).t; }