This is needed to support CHERI, and thus Arm's experimental Morello
prototype, where pointers are implemented using unforgeable capabilities
that include bounds and permissions metadata to provide fine-grained
spatial and referential memory safety, as well as revocation by sweeping
memory to provide heap temporal memory safety.
On most systems (anything with a flat memory hierarchy rather than using
segment-based addressing), size_t and uintptr_t are the same type.
However, on CHERI, size_t is just an integer offset, whereas uintptr_t
is still a capability as described above. Casting a pointer to size_t
will strip the metadata and validity tag, and casting from size_t to a
pointer will result in a null-derived capability whose validity tag is
not set, and thus cannot be dereferenced without faulting.
The audio and cursor casts were harmless as they intend to stuff an
integer into a pointer, but using uintptr_t is the idiomatic way to do
that and silences our compiler warnings (which our build tool makes
fatal by default as they often indicate real problems). The iconv and
egl casts were true positives as SDL_iconv_t and iconv_t are pointer
types, as is NativeDisplayType on most OSes, so this would have trapped
at run time when using the round-tripped pointers. The gles2 casts were
also harmless; the OpenGL API defines this argument to be a pointer type
(and uses the argument name "pointer"), but it in fact represents an
integer offset, so like audio and cursor the additional idiomatic cast
is needed to silence the warning.
SDL_isxdigit() should only accept A-Fa-f, not A-Za-z (it shouldn't use
SDL_isalpha()).
SDL_ispunct() shouldn't accept spaces (it should use SDL_isgraph()
instead).
SDL has been missing a bunch of these 'isX' functions for some time,
where X is some characteristic of a given character.
This commit adds the rest of them to the SDL stdlib, so now we have:
- SDL_isalpha()
- SDL_isalnum()
- SDL_isblank()
- SDL_iscntrl()
- SDL_isxdigit()
- SDL_ispunct()
- SDL_isprint()
- SDL_isgraph()
Cameron Cawley
stdlib: Added SDL_round, SDL_roundf, SDL_lround and SDL_lroundf
The default implementation is based on the one used in the Windows RT video driver.
dark_sylinc
Trying to build SDL with VS2019 using CMake will encounter a linking error
More specifically:
1>SDL_string.obj : error LNK2019: unresolved external symbol memset referenced in function SDL_vsnprintf_REAL
ciremo6483
In `SDL_iconv_string` the `while (inbytesleft > 0)` loop can end up in a state where it never terminates because the library `iconv` function called from `SDL_iconv` doesn't consume any bytes.
This happened when a `WCHAR_T` input string was being converted to `UTF-8` but contained invalid characters. It would first It would first skip a few bytes due to `case SDL_ICONV_EILSEQ` but when there were 3 bytes remaining of `inbytesleft` `iconv` just didn't consume anything more (but didn't throw an error either).
It just so happens that the Microsoft Classic IntelliMouse `product_string` contains such invalid characters (`"Microsoft? Classic IntelliMouse?"`), meaning the function would get stuck with said mouse plugged in.
A fix for this would be to check if `inbytesleft` was unchanged after an iteration and in that case either decrement the counter like when `SDL_ICONV_EILSEQ` is returned or simply break the loop.
it used to place zeroes between the sign and the number. (space-padding
from within SDL_PrintString() seems OK: spaces are added before sign.)
also fixed the maxlen handling if the number has a sign.
- remove force-enabling of pad_zeroes for %u for compatibility
(was added in https://hg.libsdl.org/SDL/rev/701f4a25df89)
- ignore pad_zeroes for %s and %S
- ignore pad_zeroes for %d, %i and %u if a precision is given
