https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108761
Bug ID: 108761
Summary: Add option to produce a unique section for non-COMDAT
__attribute__((section("foo"))) object
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: i at maskray dot me
Target Milestone: ---
% cat a.cc
__attribute__((section("foo"))) void f() {}
__attribute__((section("foo"))) void g() {}
% g++ -c -ffunction-sections a.cc
% readelf -WS a.o | grep foo
[ 4] foo PROGBITS 0000000000000000 000040 00000e 00 AX
0 0 1
There is one section named `foo`, with f and g in it (they do not use COMDAT).
In ld --gc-sections, f and g are retained or discarded as a unit.
If we place f and g in two `foo` sections, --gc-sections can discard them
separately.
(We need assembler syntax `.section foo,"ax",@progbits,unique,1` which requires
binutils>=2.35.)
https://reviews.llvm.org/D143745 proposes to add such a feature with an option
name like `-ffunction-sections[=(default,all)]`.
I feel that the option argument is non-intuitive but do not come up with a
better name right now.
I raise this feature request to seek feedback from GCC :)
