https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119585
Bug ID: 119585
Summary: counted_by in redefined structs.
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: uecker at gcc dot gnu.org
Target Milestone: ---
I think it would be useful if we allowed redefinitions of struct that add
counted_by.
This would allow enhancing a struct declared in a header later:
struct foo { int n; char buf[]; }; // some header outside of my control
struct foo { int n; [[gnu::counted_by(n)]] char buf[]; }; // my code
Currently we are very strict in not allowing this, but this case (in contrast
to inconsistent counted_by attributes which should still be rejected) seems
safe and useful.
https://godbolt.org/z/zjcq16Exd
