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10.46.13 calloc ¶

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9799919799/functions/calloc.html

Gnulib module: calloc-posix

Portability problems fixed by Gnulib:

• On some platforms, when the function fails it does not set errno: mingw, MSVC 14.
• On some platforms, when the function fails it might set errno to EAGAIN instead of to ENOMEM. Although POSIX allows EAGAIN, the calloc-posix module insists on ENOMEM which also conforms to POSIX and is GNU-compatible: Solaris 11.4.
• On some platforms, calloc (n, s) can succeed even if multiplying n by s would exceed PTRDIFF_MAX or SIZE_MAX. Although failing to check for exceeding PTRDIFF_MAX is arguably allowed by POSIX it can lead to undefined behavior later, so calloc-posix does not allow going over the limit.

Extension: Gnulib provides a module ‘calloc-gnu’ that substitutes a calloc implementation that behaves more like the glibc implementation. It fixes this portability problem:

• calloc (0, s) and calloc (n, 0) return NULL on success on some platforms: AIX 7.3.