The eBPF loader expects to find entries for functions declared as extern
in the corresponding BTF_KIND_DATASEC record, but we were not generating
these entries.
This patch adds support for the 'extern' linkage of function types in
BTF, and creates entries for for them BTF_KIND_DATASEC records as needed.
PR target/106773
gcc/
* btfout.cc (get_section_name): New function.
(btf_collect_datasec): Use it here. Process functions, marking them
'extern' and generating DATASEC entries for them as appropriate. Move
creation of BTF_KIND_FUNC records to here...
(btf_dtd_emit_preprocess_cb): ... from here.
gcc/testsuite/
* gcc.dg/debug/btf/btf-datasec-2.c: New test.
* gcc.dg/debug/btf/btf-function-6.c: New test.
include/
* btf.h (enum btf_func_linkage): New.
(struct btf_var_secinfo): Update comments with notes about extern
functions.
70b303049e