getpagesize()

[paravoid]

getpagesize()

[sbc100]

I don't see any reason not to include this.

[sunfishcode]

From a quick search, code embedding OpenBSD's reallocarray looks like this, which doesn't have a getpagesize call. Is the code you're using embedding OpenBSD's entire malloc implementation? If so, getpagesize may not be the only problem, as that would also need a real mmap. The underlying WebAssembly platform doesn't support mmap, so wasi-libc's mmap is emulated; it calls malloc to do the actual allocation, but that won't work if you're using mmap to implement malloc :-).

wasi-libc does support reallocarray, so one option would be to change the code to just use that rather than using its own bundled version.

Beyond that, C code calling functions which have been deprecated since the 1990's isn't an automatic priority for me, but getpagesize is sufficiently widely used and harmless that it'd be ok to support. I posted #300 with an implementation.

[paravoid]

This is about recallocarray(), not reallocarray(). See https://github.com/openbsd/src/blob/master/lib/libc/stdlib/recallocarray.c for the OpenBSD implementation. It's much more trivial and a wrapper on top of calloc, so no mmap required etc. I've confirmed that if one replaces getpagesize() there with PAGE_SIZE or sysconf(_SC_PAGESIZE) it builds and works just fine.

Thanks so much for the quick response & PR! I wonder, does this needs a reimplementation in the bottom half, given this is already present in the top-half and already in wasi-libc's source tree? cf.
https://github.com/WebAssembly/wasi-libc/blob/main/libc-top-half/musl/src/legacy/getpagesize.c

[sunfishcode]

This is about recallocarray(), not reallocarray(). See https://github.com/openbsd/src/blob/master/lib/libc/stdlib/recallocarray.c for the OpenBSD implementation. It's much more trivial and a wrapper on top of calloc, so no mmap required etc. I've confirmed that if one replaces getpagesize() there with PAGE_SIZE or sysconf(_SC_PAGESIZE) it builds and works just fine.

Ah, I misread that.

Thanks so much for the quick response & PR! I wonder, does this needs a reimplementation in the bottom half, given this is already present in the top-half and already in wasi-libc's source tree? cf. https://github.com/WebAssembly/wasi-libc/blob/main/libc-top-half/musl/src/legacy/getpagesize.c

I updated to PR to use the musl version.