https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107481
Bug ID: 107481
Summary: bpf: add __builtin_preserve_enum_value
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: david.faust at oracle dot com
Target Milestone: ---
LLVM supports a builtin:
__builtin_preserve_enum_value (param, flag)
which is used to generate additional relocations for the
Compile Once - Run Everywhere (CO-RE) mechanism.
This builtin produces a CO-RE relocation recording information
about the enumerator value in 'param' according to 'flag', and
returns that information to the program. For example, the
integer value of the enumerator, or a boolean value representing
whether or not that enumerator exists on the host kernel. These
values are patched by the eBPF loader according to the CO-RE
relocation.
We should support the same functionality in GCC.
These are the relevant changes in LLVM:
https://reviews.llvm.org/D83878
https://reviews.llvm.org/D83242
