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-rw-r--r--Build/source/libs/luajit/LuaJIT-src/src/lj_strscan.c547
1 files changed, 547 insertions, 0 deletions
diff --git a/Build/source/libs/luajit/LuaJIT-src/src/lj_strscan.c b/Build/source/libs/luajit/LuaJIT-src/src/lj_strscan.c
new file mode 100644
index 00000000000..d3c5ba9124f
--- /dev/null
+++ b/Build/source/libs/luajit/LuaJIT-src/src/lj_strscan.c
@@ -0,0 +1,547 @@
+/*
+** String scanning.
+** Copyright (C) 2005-2015 Mike Pall. See Copyright Notice in luajit.h
+*/
+
+#include <math.h>
+
+#define lj_strscan_c
+#define LUA_CORE
+
+#include "lj_obj.h"
+#include "lj_char.h"
+#include "lj_strscan.h"
+
+/* -- Scanning numbers ---------------------------------------------------- */
+
+/*
+** Rationale for the builtin string to number conversion library:
+**
+** It removes a dependency on libc's strtod(), which is a true portability
+** nightmare. Mainly due to the plethora of supported OS and toolchain
+** combinations. Sadly, the various implementations
+** a) are often buggy, incomplete (no hex floats) and/or imprecise,
+** b) sometimes crash or hang on certain inputs,
+** c) return non-standard NaNs that need to be filtered out, and
+** d) fail if the locale-specific decimal separator is not a dot,
+** which can only be fixed with atrocious workarounds.
+**
+** Also, most of the strtod() implementations are hopelessly bloated,
+** which is not just an I-cache hog, but a problem for static linkage
+** on embedded systems, too.
+**
+** OTOH the builtin conversion function is very compact. Even though it
+** does a lot more, like parsing long longs, octal or imaginary numbers
+** and returning the result in different formats:
+** a) It needs less than 3 KB (!) of machine code (on x64 with -Os),
+** b) it doesn't perform any dynamic allocation and,
+** c) it needs only around 600 bytes of stack space.
+**
+** The builtin function is faster than strtod() for typical inputs, e.g.
+** "123", "1.5" or "1e6". Arguably, it's slower for very large exponents,
+** which are not very common (this could be fixed, if needed).
+**
+** And most importantly, the builtin function is equally precise on all
+** platforms. It correctly converts and rounds any input to a double.
+** If this is not the case, please send a bug report -- but PLEASE verify
+** that the implementation you're comparing to is not the culprit!
+**
+** The implementation quickly pre-scans the entire string first and
+** handles simple integers on-the-fly. Otherwise, it dispatches to the
+** base-specific parser. Hex and octal is straightforward.
+**
+** Decimal to binary conversion uses a fixed-length circular buffer in
+** base 100. Some simple cases are handled directly. For other cases, the
+** number in the buffer is up-scaled or down-scaled until the integer part
+** is in the proper range. Then the integer part is rounded and converted
+** to a double which is finally rescaled to the result. Denormals need
+** special treatment to prevent incorrect 'double rounding'.
+*/
+
+/* Definitions for circular decimal digit buffer (base 100 = 2 digits/byte). */
+#define STRSCAN_DIG 1024
+#define STRSCAN_MAXDIG 800 /* 772 + extra are sufficient. */
+#define STRSCAN_DDIG (STRSCAN_DIG/2)
+#define STRSCAN_DMASK (STRSCAN_DDIG-1)
+
+/* Helpers for circular buffer. */
+#define DNEXT(a) (((a)+1) & STRSCAN_DMASK)
+#define DPREV(a) (((a)-1) & STRSCAN_DMASK)
+#define DLEN(lo, hi) ((int32_t)(((lo)-(hi)) & STRSCAN_DMASK))
+
+#define casecmp(c, k) (((c) | 0x20) == k)
+
+/* Final conversion to double. */
+static void strscan_double(uint64_t x, TValue *o, int32_t ex2, int32_t neg)
+{
+ double n;
+
+ /* Avoid double rounding for denormals. */
+ if (LJ_UNLIKELY(ex2 <= -1075 && x != 0)) {
+ /* NYI: all of this generates way too much code on 32 bit CPUs. */
+#if defined(__GNUC__) && LJ_64
+ int32_t b = (int32_t)(__builtin_clzll(x)^63);
+#else
+ int32_t b = (x>>32) ? 32+(int32_t)lj_fls((uint32_t)(x>>32)) :
+ (int32_t)lj_fls((uint32_t)x);
+#endif
+ if ((int32_t)b + ex2 <= -1023 && (int32_t)b + ex2 >= -1075) {
+ uint64_t rb = (uint64_t)1 << (-1075-ex2);
+ if ((x & rb) && ((x & (rb+rb+rb-1)))) x += rb+rb;
+ x = (x & ~(rb+rb-1));
+ }
+ }
+
+ /* Convert to double using a signed int64_t conversion, then rescale. */
+ lua_assert((int64_t)x >= 0);
+ n = (double)(int64_t)x;
+ if (neg) n = -n;
+ if (ex2) n = ldexp(n, ex2);
+ o->n = n;
+}
+
+/* Parse hexadecimal number. */
+static StrScanFmt strscan_hex(const uint8_t *p, TValue *o,
+ StrScanFmt fmt, uint32_t opt,
+ int32_t ex2, int32_t neg, uint32_t dig)
+{
+ uint64_t x = 0;
+ uint32_t i;
+
+ /* Scan hex digits. */
+ for (i = dig > 16 ? 16 : dig ; i; i--, p++) {
+ uint32_t d = (*p != '.' ? *p : *++p); if (d > '9') d += 9;
+ x = (x << 4) + (d & 15);
+ }
+
+ /* Summarize rounding-effect of excess digits. */
+ for (i = 16; i < dig; i++, p++)
+ x |= ((*p != '.' ? *p : *++p) != '0'), ex2 += 4;
+
+ /* Format-specific handling. */
+ switch (fmt) {
+ case STRSCAN_INT:
+ if (!(opt & STRSCAN_OPT_TONUM) && x < 0x80000000u+neg) {
+ o->i = neg ? -(int32_t)x : (int32_t)x;
+ return STRSCAN_INT; /* Fast path for 32 bit integers. */
+ }
+ if (!(opt & STRSCAN_OPT_C)) { fmt = STRSCAN_NUM; break; }
+ /* fallthrough */
+ case STRSCAN_U32:
+ if (dig > 8) return STRSCAN_ERROR;
+ o->i = neg ? -(int32_t)x : (int32_t)x;
+ return STRSCAN_U32;
+ case STRSCAN_I64:
+ case STRSCAN_U64:
+ if (dig > 16) return STRSCAN_ERROR;
+ o->u64 = neg ? (uint64_t)-(int64_t)x : x;
+ return fmt;
+ default:
+ break;
+ }
+
+ /* Reduce range, then convert to double. */
+ if ((x & U64x(c0000000,0000000))) { x = (x >> 2) | (x & 3); ex2 += 2; }
+ strscan_double(x, o, ex2, neg);
+ return fmt;
+}
+
+/* Parse octal number. */
+static StrScanFmt strscan_oct(const uint8_t *p, TValue *o,
+ StrScanFmt fmt, int32_t neg, uint32_t dig)
+{
+ uint64_t x = 0;
+
+ /* Scan octal digits. */
+ if (dig > 22 || (dig == 22 && *p > '1')) return STRSCAN_ERROR;
+ while (dig-- > 0) {
+ if (!(*p >= '0' && *p <= '7')) return STRSCAN_ERROR;
+ x = (x << 3) + (*p++ & 7);
+ }
+
+ /* Format-specific handling. */
+ switch (fmt) {
+ case STRSCAN_INT:
+ if (x >= 0x80000000u+neg) fmt = STRSCAN_U32;
+ /* fallthrough */
+ case STRSCAN_U32:
+ if ((x >> 32)) return STRSCAN_ERROR;
+ o->i = neg ? -(int32_t)x : (int32_t)x;
+ break;
+ default:
+ case STRSCAN_I64:
+ case STRSCAN_U64:
+ o->u64 = neg ? (uint64_t)-(int64_t)x : x;
+ break;
+ }
+ return fmt;
+}
+
+/* Parse decimal number. */
+static StrScanFmt strscan_dec(const uint8_t *p, TValue *o,
+ StrScanFmt fmt, uint32_t opt,
+ int32_t ex10, int32_t neg, uint32_t dig)
+{
+ uint8_t xi[STRSCAN_DDIG], *xip = xi;
+
+ if (dig) {
+ uint32_t i = dig;
+ if (i > STRSCAN_MAXDIG) {
+ ex10 += (int32_t)(i - STRSCAN_MAXDIG);
+ i = STRSCAN_MAXDIG;
+ }
+ /* Scan unaligned leading digit. */
+ if (((ex10^i) & 1))
+ *xip++ = ((*p != '.' ? *p : *++p) & 15), i--, p++;
+ /* Scan aligned double-digits. */
+ for ( ; i > 1; i -= 2) {
+ uint32_t d = 10 * ((*p != '.' ? *p : *++p) & 15); p++;
+ *xip++ = d + ((*p != '.' ? *p : *++p) & 15); p++;
+ }
+ /* Scan and realign trailing digit. */
+ if (i) *xip++ = 10 * ((*p != '.' ? *p : *++p) & 15), ex10--, dig++, p++;
+
+ /* Summarize rounding-effect of excess digits. */
+ if (dig > STRSCAN_MAXDIG) {
+ do {
+ if ((*p != '.' ? *p : *++p) != '0') { xip[-1] |= 1; break; }
+ p++;
+ } while (--dig > STRSCAN_MAXDIG);
+ dig = STRSCAN_MAXDIG;
+ } else { /* Simplify exponent. */
+ while (ex10 > 0 && dig <= 18) *xip++ = 0, ex10 -= 2, dig += 2;
+ }
+ } else { /* Only got zeros. */
+ ex10 = 0;
+ xi[0] = 0;
+ }
+
+ /* Fast path for numbers in integer format (but handles e.g. 1e6, too). */
+ if (dig <= 20 && ex10 == 0) {
+ uint8_t *xis;
+ uint64_t x = xi[0];
+ double n;
+ for (xis = xi+1; xis < xip; xis++) x = x * 100 + *xis;
+ if (!(dig == 20 && (xi[0] > 18 || (int64_t)x >= 0))) { /* No overflow? */
+ /* Format-specific handling. */
+ switch (fmt) {
+ case STRSCAN_INT:
+ if (!(opt & STRSCAN_OPT_TONUM) && x < 0x80000000u+neg) {
+ o->i = neg ? -(int32_t)x : (int32_t)x;
+ return STRSCAN_INT; /* Fast path for 32 bit integers. */
+ }
+ if (!(opt & STRSCAN_OPT_C)) { fmt = STRSCAN_NUM; goto plainnumber; }
+ /* fallthrough */
+ case STRSCAN_U32:
+ if ((x >> 32) != 0) return STRSCAN_ERROR;
+ o->i = neg ? -(int32_t)x : (int32_t)x;
+ return STRSCAN_U32;
+ case STRSCAN_I64:
+ case STRSCAN_U64:
+ o->u64 = neg ? (uint64_t)-(int64_t)x : x;
+ return fmt;
+ default:
+ plainnumber: /* Fast path for plain numbers < 2^63. */
+ if ((int64_t)x < 0) break;
+ n = (double)(int64_t)x;
+ if (neg) n = -n;
+ o->n = n;
+ return fmt;
+ }
+ }
+ }
+
+ /* Slow non-integer path. */
+ if (fmt == STRSCAN_INT) {
+ if ((opt & STRSCAN_OPT_C)) return STRSCAN_ERROR;
+ fmt = STRSCAN_NUM;
+ } else if (fmt > STRSCAN_INT) {
+ return STRSCAN_ERROR;
+ }
+ {
+ uint32_t hi = 0, lo = (uint32_t)(xip-xi);
+ int32_t ex2 = 0, idig = (int32_t)lo + (ex10 >> 1);
+
+ lua_assert(lo > 0 && (ex10 & 1) == 0);
+
+ /* Handle simple overflow/underflow. */
+ if (idig > 310/2) { if (neg) setminfV(o); else setpinfV(o); return fmt; }
+ else if (idig < -326/2) { o->n = neg ? -0.0 : 0.0; return fmt; }
+
+ /* Scale up until we have at least 17 or 18 integer part digits. */
+ while (idig < 9 && idig < DLEN(lo, hi)) {
+ uint32_t i, cy = 0;
+ ex2 -= 6;
+ for (i = DPREV(lo); ; i = DPREV(i)) {
+ uint32_t d = (xi[i] << 6) + cy;
+ cy = (((d >> 2) * 5243) >> 17); d = d - cy * 100; /* Div/mod 100. */
+ xi[i] = (uint8_t)d;
+ if (i == hi) break;
+ if (d == 0 && i == DPREV(lo)) lo = i;
+ }
+ if (cy) {
+ hi = DPREV(hi);
+ if (xi[DPREV(lo)] == 0) lo = DPREV(lo);
+ else if (hi == lo) { lo = DPREV(lo); xi[DPREV(lo)] |= xi[lo]; }
+ xi[hi] = (uint8_t)cy; idig++;
+ }
+ }
+
+ /* Scale down until no more than 17 or 18 integer part digits remain. */
+ while (idig > 9) {
+ uint32_t i = hi, cy = 0;
+ ex2 += 6;
+ do {
+ cy += xi[i];
+ xi[i] = (cy >> 6);
+ cy = 100 * (cy & 0x3f);
+ if (xi[i] == 0 && i == hi) hi = DNEXT(hi), idig--;
+ i = DNEXT(i);
+ } while (i != lo);
+ while (cy) {
+ if (hi == lo) { xi[DPREV(lo)] |= 1; break; }
+ xi[lo] = (cy >> 6); lo = DNEXT(lo);
+ cy = 100 * (cy & 0x3f);
+ }
+ }
+
+ /* Collect integer part digits and convert to rescaled double. */
+ {
+ uint64_t x = xi[hi];
+ uint32_t i;
+ for (i = DNEXT(hi); --idig > 0 && i != lo; i = DNEXT(i))
+ x = x * 100 + xi[i];
+ if (i == lo) {
+ while (--idig >= 0) x = x * 100;
+ } else { /* Gather round bit from remaining digits. */
+ x <<= 1; ex2--;
+ do {
+ if (xi[i]) { x |= 1; break; }
+ i = DNEXT(i);
+ } while (i != lo);
+ }
+ strscan_double(x, o, ex2, neg);
+ }
+ }
+ return fmt;
+}
+
+/* Parse binary number. */
+static StrScanFmt strscan_bin(const uint8_t *p, TValue *o,
+ StrScanFmt fmt, uint32_t opt,
+ int32_t ex2, int32_t neg, uint32_t dig)
+{
+ uint64_t x = 0;
+ uint32_t i;
+
+ if (ex2 || dig > 64) return STRSCAN_ERROR;
+
+ /* Scan binary digits. */
+ for (i = dig; i; i--, p++) {
+ if ((*p & ~1) != '0') return STRSCAN_ERROR;
+ x = (x << 1) | (*p & 1);
+ }
+
+ /* Format-specific handling. */
+ switch (fmt) {
+ case STRSCAN_INT:
+ if (!(opt & STRSCAN_OPT_TONUM) && x < 0x80000000u+neg) {
+ o->i = neg ? -(int32_t)x : (int32_t)x;
+ return STRSCAN_INT; /* Fast path for 32 bit integers. */
+ }
+ if (!(opt & STRSCAN_OPT_C)) { fmt = STRSCAN_NUM; break; }
+ /* fallthrough */
+ case STRSCAN_U32:
+ if (dig > 32) return STRSCAN_ERROR;
+ o->i = neg ? -(int32_t)x : (int32_t)x;
+ return STRSCAN_U32;
+ case STRSCAN_I64:
+ case STRSCAN_U64:
+ o->u64 = neg ? (uint64_t)-(int64_t)x : x;
+ return fmt;
+ default:
+ break;
+ }
+
+ /* Reduce range, then convert to double. */
+ if ((x & U64x(c0000000,0000000))) { x = (x >> 2) | (x & 3); ex2 += 2; }
+ strscan_double(x, o, ex2, neg);
+ return fmt;
+}
+
+/* Scan string containing a number. Returns format. Returns value in o. */
+StrScanFmt lj_strscan_scan(const uint8_t *p, TValue *o, uint32_t opt)
+{
+ int32_t neg = 0;
+
+ /* Remove leading space, parse sign and non-numbers. */
+ if (LJ_UNLIKELY(!lj_char_isdigit(*p))) {
+ while (lj_char_isspace(*p)) p++;
+ if (*p == '+' || *p == '-') neg = (*p++ == '-');
+ if (LJ_UNLIKELY(*p >= 'A')) { /* Parse "inf", "infinity" or "nan". */
+ TValue tmp;
+ setnanV(&tmp);
+ if (casecmp(p[0],'i') && casecmp(p[1],'n') && casecmp(p[2],'f')) {
+ if (neg) setminfV(&tmp); else setpinfV(&tmp);
+ p += 3;
+ if (casecmp(p[0],'i') && casecmp(p[1],'n') && casecmp(p[2],'i') &&
+ casecmp(p[3],'t') && casecmp(p[4],'y')) p += 5;
+ } else if (casecmp(p[0],'n') && casecmp(p[1],'a') && casecmp(p[2],'n')) {
+ p += 3;
+ }
+ while (lj_char_isspace(*p)) p++;
+ if (*p) return STRSCAN_ERROR;
+ o->u64 = tmp.u64;
+ return STRSCAN_NUM;
+ }
+ }
+
+ /* Parse regular number. */
+ {
+ StrScanFmt fmt = STRSCAN_INT;
+ int cmask = LJ_CHAR_DIGIT;
+ int base = (opt & STRSCAN_OPT_C) && *p == '0' ? 0 : 10;
+ const uint8_t *sp, *dp = NULL;
+ uint32_t dig = 0, hasdig = 0, x = 0;
+ int32_t ex = 0;
+
+ /* Determine base and skip leading zeros. */
+ if (LJ_UNLIKELY(*p <= '0')) {
+ if (*p == '0') {
+ if (casecmp(p[1], 'x'))
+ base = 16, cmask = LJ_CHAR_XDIGIT, p += 2;
+ else if (casecmp(p[1], 'b'))
+ base = 2, cmask = LJ_CHAR_DIGIT, p += 2;
+ }
+ for ( ; ; p++) {
+ if (*p == '0') {
+ hasdig = 1;
+ } else if (*p == '.') {
+ if (dp) return STRSCAN_ERROR;
+ dp = p;
+ } else {
+ break;
+ }
+ }
+ }
+
+ /* Preliminary digit and decimal point scan. */
+ for (sp = p; ; p++) {
+ if (LJ_LIKELY(lj_char_isa(*p, cmask))) {
+ x = x * 10 + (*p & 15); /* For fast path below. */
+ dig++;
+ } else if (*p == '.') {
+ if (dp) return STRSCAN_ERROR;
+ dp = p;
+ } else {
+ break;
+ }
+ }
+ if (!(hasdig | dig)) return STRSCAN_ERROR;
+
+ /* Handle decimal point. */
+ if (dp) {
+ fmt = STRSCAN_NUM;
+ if (dig) {
+ ex = (int32_t)(dp-(p-1)); dp = p-1;
+ while (ex < 0 && *dp-- == '0') ex++, dig--; /* Skip trailing zeros. */
+ if (base == 16) ex *= 4;
+ }
+ }
+
+ /* Parse exponent. */
+ if (base >= 10 && casecmp(*p, (uint32_t)(base == 16 ? 'p' : 'e'))) {
+ uint32_t xx;
+ int negx = 0;
+ fmt = STRSCAN_NUM; p++;
+ if (*p == '+' || *p == '-') negx = (*p++ == '-');
+ if (!lj_char_isdigit(*p)) return STRSCAN_ERROR;
+ xx = (*p++ & 15);
+ while (lj_char_isdigit(*p)) {
+ if (xx < 65536) xx = xx * 10 + (*p & 15);
+ p++;
+ }
+ ex += negx ? -(int32_t)xx : (int32_t)xx;
+ }
+
+ /* Parse suffix. */
+ if (*p) {
+ /* I (IMAG), U (U32), LL (I64), ULL/LLU (U64), L (long), UL/LU (ulong). */
+ /* NYI: f (float). Not needed until cp_number() handles non-integers. */
+ if (casecmp(*p, 'i')) {
+ if (!(opt & STRSCAN_OPT_IMAG)) return STRSCAN_ERROR;
+ p++; fmt = STRSCAN_IMAG;
+ } else if (fmt == STRSCAN_INT) {
+ if (casecmp(*p, 'u')) p++, fmt = STRSCAN_U32;
+ if (casecmp(*p, 'l')) {
+ p++;
+ if (casecmp(*p, 'l')) p++, fmt += STRSCAN_I64 - STRSCAN_INT;
+ else if (!(opt & STRSCAN_OPT_C)) return STRSCAN_ERROR;
+ else if (sizeof(long) == 8) fmt += STRSCAN_I64 - STRSCAN_INT;
+ }
+ if (casecmp(*p, 'u') && (fmt == STRSCAN_INT || fmt == STRSCAN_I64))
+ p++, fmt += STRSCAN_U32 - STRSCAN_INT;
+ if ((fmt == STRSCAN_U32 && !(opt & STRSCAN_OPT_C)) ||
+ (fmt >= STRSCAN_I64 && !(opt & STRSCAN_OPT_LL)))
+ return STRSCAN_ERROR;
+ }
+ while (lj_char_isspace(*p)) p++;
+ if (*p) return STRSCAN_ERROR;
+ }
+
+ /* Fast path for decimal 32 bit integers. */
+ if (fmt == STRSCAN_INT && base == 10 &&
+ (dig < 10 || (dig == 10 && *sp <= '2' && x < 0x80000000u+neg))) {
+ int32_t y = neg ? -(int32_t)x : (int32_t)x;
+ if ((opt & STRSCAN_OPT_TONUM)) {
+ o->n = (double)y;
+ return STRSCAN_NUM;
+ } else {
+ o->i = y;
+ return STRSCAN_INT;
+ }
+ }
+
+ /* Dispatch to base-specific parser. */
+ if (base == 0 && !(fmt == STRSCAN_NUM || fmt == STRSCAN_IMAG))
+ return strscan_oct(sp, o, fmt, neg, dig);
+ if (base == 16)
+ fmt = strscan_hex(sp, o, fmt, opt, ex, neg, dig);
+ else if (base == 2)
+ fmt = strscan_bin(sp, o, fmt, opt, ex, neg, dig);
+ else
+ fmt = strscan_dec(sp, o, fmt, opt, ex, neg, dig);
+
+ /* Try to convert number to integer, if requested. */
+ if (fmt == STRSCAN_NUM && (opt & STRSCAN_OPT_TOINT)) {
+ double n = o->n;
+ int32_t i = lj_num2int(n);
+ if (n == (lua_Number)i) { o->i = i; return STRSCAN_INT; }
+ }
+ return fmt;
+ }
+}
+
+int LJ_FASTCALL lj_strscan_num(GCstr *str, TValue *o)
+{
+ StrScanFmt fmt = lj_strscan_scan((const uint8_t *)strdata(str), o,
+ STRSCAN_OPT_TONUM);
+ lua_assert(fmt == STRSCAN_ERROR || fmt == STRSCAN_NUM);
+ return (fmt != STRSCAN_ERROR);
+}
+
+#if LJ_DUALNUM
+int LJ_FASTCALL lj_strscan_number(GCstr *str, TValue *o)
+{
+ StrScanFmt fmt = lj_strscan_scan((const uint8_t *)strdata(str), o,
+ STRSCAN_OPT_TOINT);
+ lua_assert(fmt == STRSCAN_ERROR || fmt == STRSCAN_NUM || fmt == STRSCAN_INT);
+ if (fmt == STRSCAN_INT) setitype(o, LJ_TISNUM);
+ return (fmt != STRSCAN_ERROR);
+}
+#endif
+
+#undef DNEXT
+#undef DPREV
+#undef DLEN
+