Currenly when linking FreeBSD kernel LLD produces 7 different .rodata sections because of difference
in attributes:
[ 6] .rodata PROGBITS ffffffff80c87c8c 00c86c8c 00000000000e6e4d 0000000000000001 AMS 0 0 1 [ 7] .rodata PROGBITS ffffffff80d6eae0 00d6dae0 0000000000246f00 0000000000000000 A 0 0 32 [ 8] .rodata PROGBITS ffffffff80fb59e0 00fb49e0 00000000000001f0 0000000000000010 AM 0 0 16 [ 9] .rodata PROGBITS ffffffff80fb5bd0 00fb4bd0 00000000000002a0 0000000000000004 AMS 0 0 16 [10] .rodata PROGBITS ffffffff80fb5e70 00fb4e70 0000000000000108 0000000000000008 AM 0 0 8 [11] .rodata PROGBITS ffffffff80fb5f78 00fb4f78 000000000000000c 0000000000000004 AMS 0 0 4 [12] .rodata PROGBITS ffffffff80fb5f88 00fb4f88 0000000000001158 0000000000000001 AMS 0 0 8
At the same time ld produce only one. That probably means we need to use different logic for
creating output sections when do scripted layout.
Patch stops exporting regular output sections factory and introduces new one for using from
linker script side. That allowed to implement combining of output sections with different attributes.
Currently implemention does not support combine of SHT_MERGE sections with non-SHT_MERGE. But I believe
it should be not hard to implement basing on these new changes. One of possible way probably would be
to do scan of input sections to find out if there is a mix of "aM" vs "a" for example, and if so - do not create
megreable output section, but create regular one that should support adding mergeable input sections
as regular ones.