forked from OSchip/llvm-project
36c8621638
This patch follows D85345 and adds more noundef attributes to return values/arguments of library functions that are mostly about accessing the file system or processes. A few functions like `chmod` or `times` use typedef `mode_t` and `clock_t`. They are neither struct nor union, so they cannot contain undef even if they're lowered to iN in IR. So, it is fine to add noundef to them. - clock_t's actual type is size_t (C17, 7.27.1.3), so it isn't struct or union. - For mode_t, either int or long is used in practice because programmers use bit manipulation. So, I think it is okay that it's never aggregate in practice. After this patch, the remaining library functions are those that eagerly participate in optimizations: they can be removed, reordered, or introduced by a transformation from primitive IR operations. For them, a few testings is needed, since it may not be valid to add noundef anymore even if C standard says it's okay. Reviewed By: jdoerfert Differential Revision: https://reviews.llvm.org/D85894 |
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| annotate.ll | ||
| dereferenceable.ll | ||
| no-proto.ll | ||
| norecurse_debug.ll | ||
| pr30455.ll | ||