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snprintf not cross-platform compilable #28

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tangoalx opened this issue Aug 22, 2019 · 1 comment · Fixed by #50
Closed

snprintf not cross-platform compilable #28

tangoalx opened this issue Aug 22, 2019 · 1 comment · Fixed by #50

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@tangoalx
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The following call leads to an compilation error with Microsoft Visual Studio 2010 VCC, because the function snprintf is not known:

kaitai_struct_cpp_stl_runtime/kaitai/kaitaistream.cpp

Line 541 in da224cb

int got_len = snprintf(buf, sizeof(buf), "%d", val);

The function is called _snprintf on windows system (just prepend underscore). However, _snprintf is deprecated and I'm not sure, if it has already been removed from newer versions of MSVS. Furthermore snprintf and _snprintf do not behave the same way in all situations (see example on stack-overflow-thread or tests on various platforms on demin-blog)

Maybe there is an alternative solution, which works cross-platform, but I didn't find a cross-platform implementation yet (other than implementing the function anew).
@GreyCat
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GreyCat commented Sep 9, 2019

Probably we can get away by outputting this to in-memory string stream and then returning its contents?

@sykhro sykhro mentioned this issue Mar 26, 2021
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generalmimon added a commit that referenced this issue Apr 2, 2022
@generalmimon
Replace kstream::to_string() - not just int, fix portability
5ee4e19 
See #8 (comment)

Fix #28,
close #39
@generalmimon generalmimon mentioned this issue Apr 3, 2022
Merged
generalmimon added a commit that referenced this issue Apr 7, 2022
@generalmimon
Replace kstream::to_string() - not just int, fix portability (#50)
da0d91f 
* Replace kstream::to_string() - not just `int`, fix portability

See #8 (comment)

Fix #28,
close #39

* Simplify to_string(): accept `uint64_t` in unsigned_to_decimal()

* to_string(): only allow types whose absolute value fits into `uint64_t`

We only check `std::numeric_limits<I>::max()`, because `min()` is
negative for signed types, and we need its absolute value (so we can
compare it with `std::numeric_limits<uint64_t>::max()`). However, this
value won't fit into the same signed type in two's complement
representation, so we need to use at least an unsigned type of the same
width - but in GCC, `std::make_unsigned<__int128_t>` is not available,
and `uintmax_t` is `uint64_t`, not `__uint128_t`. I don't know how to
get the "real" `uintmax_t` including implementation-specific extended
types like `__uint128_t` - maybe there's no platform-independent way to
do it.

Fortunately, we don't have to deal with this for the `max()` case at
all, which works just fine, so we'll at least check that.
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Replace kstream::to_string() - not just int, fix portability kaitai-io/kaitai_struct_cpp_stl_runtime
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@GreyCat @tangoalx