From: Maxim Kokryashkin via Tarantool-patches <tarantool-patches@dev.tarantool.org> To: tarantool-patches@dev.tarantool.org, imun@tarantool.org, skaplun@tarantool.org Subject: [Tarantool-patches] [PATCH luajit] luajit-gdb: support dualnum mode Date: Sat, 31 Jul 2021 16:36:48 +0300 [thread overview] Message-ID: <20210731133648.25660-1-m.kokryashkin@tarantool.org> (raw) For x86/x64 LJ_DUALNUM mode is disabled. But for some other arches (arm or arm64, for example) it is enabled by default. luajit-gdb.py displays integers in LJ_DUALNUM mode as nan-s. As it turned out, luajit-gdb detects those integers as integers, but there was a problem with the dumper function itself. The dumper function produces output thinking of any input value as of a double. However, in DUALNUM mode, integers and floats are stored differently, so the `itype` of a float number must be less than `LJ_TISNUM`, and the `itype` of an integer must be `LJ_TISNUM`. With this fact in mind, we can easily differentiate one from another. But in any mode, lua numbers are stored as doubles on the C side, so it takes an ugly cast chain on the Python side to perform the some sort of the `reinterpret_cast` because the gdb module doesn't have any mechanism to get the address of a symbol. Closes tarantool/tarantool#6224 --- Github branch: https://github.com/tarantool/luajit/tree/fckxorg/gh-6224-support-dulanum Issue: https://github.com/tarantool/tarantool/issues/6224 For more info, see line 273 in lj_obj.h src/luajit-gdb.py | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/luajit-gdb.py b/src/luajit-gdb.py index c50405ad..5f79c277 100644 --- a/src/luajit-gdb.py +++ b/src/luajit-gdb.py @@ -343,7 +343,11 @@ def dump_lj_tudata(tv): return 'userdata @ {}'.format(strx64(gcval(tv['gcr']))) def dump_lj_tnumx(tv): - return 'number {}'.format(cast('double', tv['n'])) + if itype(tv) == (0xfffeffff if LJ_64 and not LJ_GC64 else LJ_T['NUMX']): + integer = cast('int32_t', cast('uint64_t', cast('void*', tv['n'])) & 0xFFFFFFFF) + return 'number {}'.format(integer) + else: + return 'number {}'.format(cast('double', tv['n'])) def dump_lj_invalid(tv): return 'not valid type @ {}'.format(strx64(gcval(tv['gcr']))) -- 2.32.0
next reply other threads:[~2021-07-31 13:36 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-31 13:36 Maxim Kokryashkin via Tarantool-patches [this message] 2021-08-11 8:27 ` Sergey Kaplun via Tarantool-patches 2021-08-13 14:29 ` Максим Корякшин via Tarantool-patches 2021-08-14 11:38 ` [Tarantool-patches] [PATCH luajit v2] " Maxim Kokryashkin via Tarantool-patches 2021-08-14 13:36 ` Максим Корякшин via Tarantool-patches 2021-08-14 13:47 ` Sergey Kaplun via Tarantool-patches 2021-08-14 17:26 ` Максим Корякшин via Tarantool-patches 2021-08-17 7:56 ` Igor Munkin via Tarantool-patches 2021-08-16 8:49 ` Igor Munkin via Tarantool-patches 2021-08-16 10:01 ` Максим Корякшин via Tarantool-patches 2021-08-16 16:23 ` Vitaliia Ioffe via Tarantool-patches 2021-08-17 7:47 ` Igor Munkin via Tarantool-patches 2021-08-17 9:23 ` [Tarantool-patches] [PATCH luajit] " Igor Munkin via Tarantool-patches
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