[Tarantool-patches] [PATCH luajit 2/2] Fix tonumber("-0") in dual-number mode.
sergos
sergos at tarantool.org
Mon Jun 27 18:51:09 MSK 2022
Hi!
Thanks for the patch, jut nits in the changelog.
LGTM
Sergos
> On 26 Jan 2022, at 15:19, Sergey Kaplun <skaplun at tarantool.org> wrote:
>
> From: Mike Pall <mike>
>
> Reported by Sergey Kaplun.
>
> For DUALNUM build `tonumber("-0x0")` or `tonumber("-0")` returns 0
the a call to to
> instead -0 due to the STRSCAN_OPT_TOINT option of `lj_strscan_scan()`
of the
> and cast value to integer with losing information about its sign.
a of the
>
> This patch adds special checks for these corner cases during strscan.
The
>
> Sergey Kaplun:
> * added the description and the test for the problem
>
> Part of tarantool/tarantool#6548
> ---
> src/lj_strscan.c | 8 ++++++--
> test/tarantool-tests/lj-528-tonumber-0.test.lua | 10 ++--------
> 2 files changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/src/lj_strscan.c b/src/lj_strscan.c
> index 4e4ef6d3..11d341ee 100644
> --- a/src/lj_strscan.c
> +++ b/src/lj_strscan.c
> @@ -121,7 +121,8 @@ static StrScanFmt strscan_hex(const uint8_t *p, TValue *o,
> /* Format-specific handling. */
> switch (fmt) {
> case STRSCAN_INT:
> - if (!(opt & STRSCAN_OPT_TONUM) && x < 0x80000000u+neg) {
> + if (!(opt & STRSCAN_OPT_TONUM) && x < 0x80000000u+neg &&
> + !(x == 0 && neg)) {
> o->i = neg ? -(int32_t)x : (int32_t)x;
> return STRSCAN_INT; /* Fast path for 32 bit integers. */
> }
> @@ -498,6 +499,9 @@ StrScanFmt lj_strscan_scan(const uint8_t *p, MSize len, TValue *o,
> if ((opt & STRSCAN_OPT_TONUM)) {
> o->n = neg ? -(double)x : (double)x;
> return STRSCAN_NUM;
> + } else if (x == 0 && neg) {
> + o->n = -0.0;
> + return STRSCAN_NUM;
> } else {
> o->i = neg ? -(int32_t)x : (int32_t)x;
> return STRSCAN_INT;
> @@ -515,7 +519,7 @@ StrScanFmt lj_strscan_scan(const uint8_t *p, MSize len, TValue *o,
> 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)) {
> + if (fmt == STRSCAN_NUM && (opt & STRSCAN_OPT_TOINT) && !tvismzero(o)) {
> double n = o->n;
> int32_t i = lj_num2int(n);
> if (n == (lua_Number)i) { o->i = i; return STRSCAN_INT; }
> diff --git a/test/tarantool-tests/lj-528-tonumber-0.test.lua b/test/tarantool-tests/lj-528-tonumber-0.test.lua
> index 03ba2aff..f3ad53d3 100644
> --- a/test/tarantool-tests/lj-528-tonumber-0.test.lua
> +++ b/test/tarantool-tests/lj-528-tonumber-0.test.lua
> @@ -1,15 +1,9 @@
> local tap = require('tap')
>
> --- Test disabled for DUALNUM mode default for some arches.
> --- See also https://github.com/LuaJIT/LuaJIT/pull/787.
> -require("utils").skipcond(
> - jit.arch ~= "x86" and jit.arch ~= "x64",
> - jit.arch.." in DUALNUM mode is clumsy for now"
> -)
> -
> -- Test file to demonstrate LuaJIT `tonumber('-0')` incorrect
> -- behaviour.
> --- See also https://github.com/LuaJIT/LuaJIT/issues/528.
> +-- See also https://github.com/LuaJIT/LuaJIT/issues/528,
> +-- https://github.com/LuaJIT/LuaJIT/pull/787.
> local test = tap.test('lj-528-tonumber-0')
> test:plan(1)
>
> --
> 2.34.1
>
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