Attribute for Function that does not write to memory that outlives itself

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#1

Hi all,

Is there a function attribute or otherwise way to query whether a function could write to memory that outlives itself?

For example writing to a global or memory passed in via a function argument would be writing to memory that outlives the function, but writing to a stack variable or allocation that isn’t returned would not.

Cheers,
Billy Moses

#2

Pure or const are similar to what you want but not exactly the same to what you’re describing.

#3

LLVM-IR: readnone/readonly/writeonly on functions is almost what you
want. They basically that from the perspective of the caller there is no
visible access/write/read.