On Mon, Oct 28, 2024 at 08:18:39PM +0200, Ilpo Järvinen wrote: > I went to archives and found out it had already made itself into > include/linux/cleanup.h which now says this: > > " > * Now, when a function uses both __free() and guard(), or multiple > * instances of __free(), the LIFO order of variable definition order > * matters. GCC documentation says: > * > * "When multiple variables in the same scope have cleanup attributes, > * at exit from the scope their associated cleanup functions are run in > * reverse order of definition (last defined, first cleanup)." > * > * When the unwind order matters it requires that variables be defined > * mid-function scope rather than at the top of the file. > > [...snip examples...] > > * Given that the "__free(...) = NULL" pattern for variables defined at > * the top of the function poses this potential interdependency problem > * the recommendation is to always define and assign variables in one > * statement and not group variable definitions at the top of the > * function when __free() is used. > " > > After reading the documentation for real now myself :-), I realized it's > not just about maintainer preferences but about order of releasing things, > so it's a BAD PATTERN to put those declarations into the usual place when > using __free(). Okay, I can't argue against that... It still looks unpleasant. :)
