[PATCH] ELF: Support the section flag 'o' in .section directive

Thu Feb 6 07:46:00 GMT 2020

On Mon, Feb 03, 2020 at 06:37:17AM -0800, H.J. Lu wrote:
> bfd/
> 
> 	PR gas/25381
> 	* bfd-in2.h: Regenerated.
> 	* elf32-arm.c (elf32_arm_gc_mark_extra_sections): Call
> 	_bfd_elf_gc_mark_extra_sections last.
> 	* elf32-csky.c (_bfd_elf_gc_mark_extra_sections): Likewise.
> 	* elf32-tic6x.c (elf32_tic6x_gc_mark_extra_sections): Likewise.
> 	* elfxx-mips.c (_bfd_mips_elf_gc_mark_extra_sections): Likewise.
> 	* elflink.c (_bfd_elf_gc_mark_extra_sections): Set gc_mark only
> 	if gc_mark of any of its linked-to section is set and don't set
> 	gc_mark again.
> 	* section.c (asection): Add linked_to_symbol_name to map_head
> 	union.
> 
> gas/
> 
> 	PR gas/25381
> 	* config/obj-elf.c (get_section): Also check
> 	linked_to_symbol_name.
> 	(obj_elf_change_section): Also set map_head.linked_to_symbol_name.
> 	(obj_elf_parse_section_letters): Handle the 'o' flag.
> 	(build_group_lists): Renamed to ...
> 	(build_additional_section_info): This.  Set elf_linked_to_section
> 	from map_head.linked_to_symbol_name.
> 	(elf_adjust_symtab): Updated.
> 	* config/obj-elf.h (elf_section_match): Add linked_to_symbol_name.
> 	* doc/as.texi: Document the 'o' flag.
> 	* testsuite/gas/elf/elf.exp: Run PR gas/25381 tests.
> 	* testsuite/gas/elf/section18.d: New file.
> 	* testsuite/gas/elf/section18.s: Likewise.
> 	* testsuite/gas/elf/section19.d: Likewise.
> 	* testsuite/gas/elf/section19.s: Likewise.
> 	* testsuite/gas/elf/section20.d: Likewise.
> 	* testsuite/gas/elf/section20.s: Likewise.
> 	* testsuite/gas/elf/section21.d: Likewise.
> 	* testsuite/gas/elf/section21.l: Likewise.
> 	* testsuite/gas/elf/section21.s: Likewise.
> 
> ld/
> 
> 	PR ld/24526
> 	PR ld/25021
> 	PR ld/25490
> 	* testsuite/ld-elf/elf.exp: Run PR ld/25490 tests.
> 	* testsuite/ld-elf/pr24526.d: New file.
> 	* testsuite/ld-elf/pr24526.s: Likewise.
> 	* testsuite/ld-elf/pr25021.d: Likewise.
> 	* testsuite/ld-elf/pr25021.s: Likewise.
> 	* testsuite/ld-elf/pr25490-2-32.rd: Likewise.
> 	* testsuite/ld-elf/pr25490-2-64.rd: Likewise.
> 	* testsuite/ld-elf/pr25490-2.s: Likewise.
> 	* testsuite/ld-elf/pr25490-3-32.rd: Likewise.
> 	* testsuite/ld-elf/pr25490-3-64.rd: Likewise.
> 	* testsuite/ld-elf/pr25490-3.s: Likewise.
> 	* testsuite/ld-elf/pr25490-4-32.rd: Likewise.
> 	* testsuite/ld-elf/pr25490-4-64.rd: Likewise.
> 	* testsuite/ld-elf/pr25490-4.s: Likewise.
> 	* testsuite/ld-elf/pr25490-5-32.rd: Likewise.
> 	* testsuite/ld-elf/pr25490-5-64.rd: Likewise.
> 	* testsuite/ld-elf/pr25490-5.s: Likewise.
> 	* testsuite/ld-elf/pr25490-6-32.rd: Likewise.
> 	* testsuite/ld-elf/pr25490-6-64.rd: Likewise.
> 	* testsuite/ld-elf/pr25490-6.s: Likewise.

I see rather a lot of fails for the new testcases.  Some changes to
the testcases clearly are needed before this can go in.  A quick
glance shows two major problems:
1) You don't want to run a testcase requiring --gc-sections on a
   target that doesn't support --gc-sections.
2) You assume .dc.a sizes are only 4 or 8 but we have a number of
   targets that have 16-bit addresses.

Also, for sh-linux, I see this in pr25490-2.o
  [ 4] __patchable_function_entries PROGBITS        00000000 000038 000004 00 WAL  1   0  4
Linking to itself?  Please do look into all these fails.

avr-elf  +FAIL: linked-to section 1
avr-elf  +FAIL: linked-to section 2
avr-elf  +FAIL: linked-to section 3
avr-elf  +FAIL: __patchable_function_entries section 2
avr-elf  +FAIL: __patchable_function_entries section 3
avr-elf  +FAIL: __patchable_function_entries section 4
avr-elf  +FAIL: __patchable_function_entries section 5
avr-elf  +FAIL: __patchable_function_entries section 6
bfin-linux-uclibc  +FAIL: ld-elf/pr24526
bfin-linux-uclibc  +FAIL: ld-elf/pr25021
bfin-linux-uclibc  +FAIL: __patchable_function_entries section 4
bfin-linux-uclibc  +FAIL: __patchable_function_entries section 6
d30v-elf  +FAIL: ld-elf/pr24526
d30v-elf  +FAIL: ld-elf/pr25021
dlx-elf  +FAIL: ld-elf/pr24526
dlx-elf  +FAIL: ld-elf/pr25021
frv-linux  +FAIL: ld-elf/pr24526
frv-linux  +FAIL: ld-elf/pr25021
frv-linux  +FAIL: __patchable_function_entries section 4
frv-linux  +FAIL: __patchable_function_entries section 6
h8300-elf  +FAIL: linked-to section 1
h8300-elf  +FAIL: linked-to section 2
h8300-elf  +FAIL: linked-to section 3
h8300-elf  +FAIL: __patchable_function_entries section 2
h8300-elf  +FAIL: __patchable_function_entries section 3
h8300-elf  +FAIL: __patchable_function_entries section 4
h8300-elf  +FAIL: __patchable_function_entries section 5
h8300-elf  +FAIL: __patchable_function_entries section 6
h8300-linux  +FAIL: linked-to section 1
h8300-linux  +FAIL: linked-to section 2
h8300-linux  +FAIL: linked-to section 3
h8300-linux  +FAIL: __patchable_function_entries section 2
h8300-linux  +FAIL: __patchable_function_entries section 3
h8300-linux  +FAIL: __patchable_function_entries section 4
h8300-linux  +FAIL: __patchable_function_entries section 5
h8300-linux  +FAIL: __patchable_function_entries section 6
hppa64-hp-hpux11.23  +FAIL: ld-elf/pr24526
hppa64-hp-hpux11.23  +FAIL: ld-elf/pr25021
hppa64-linux  +FAIL: ld-elf/pr24526
hppa64-linux  +FAIL: ld-elf/pr25021
ip2k-elf  +FAIL: linked-to section 1
ip2k-elf  +FAIL: linked-to section 2
ip2k-elf  +FAIL: linked-to section 3
ip2k-elf  +FAIL: __patchable_function_entries section 2
ip2k-elf  +FAIL: __patchable_function_entries section 3
ip2k-elf  +FAIL: __patchable_function_entries section 4
ip2k-elf  +FAIL: __patchable_function_entries section 5
ip2k-elf  +FAIL: __patchable_function_entries section 6
lm32-linux  +FAIL: ld-elf/pr24526
lm32-linux  +FAIL: ld-elf/pr25021
lm32-linux  +FAIL: __patchable_function_entries section 4
lm32-linux  +FAIL: __patchable_function_entries section 6
m68hc11-elf  +FAIL: linked-to section 1
m68hc11-elf  +FAIL: linked-to section 2
m68hc11-elf  +FAIL: linked-to section 3
m68hc11-elf  +FAIL: __patchable_function_entries section 2
m68hc11-elf  +FAIL: __patchable_function_entries section 3
m68hc11-elf  +FAIL: __patchable_function_entries section 4
m68hc11-elf  +FAIL: __patchable_function_entries section 5
m68hc11-elf  +FAIL: __patchable_function_entries section 6
mep-elf  +FAIL: ld-elf/pr24526
mep-elf  +FAIL: ld-elf/pr25021
mips64el-openbsd  +FAIL: --gc-sections with relocations in debug section
mips64-openbsd  +FAIL: --gc-sections with relocations in debug section
mipstx39-elf  +FAIL: Build pr22649-2a.so
mipstx39-elf  +FAIL: Build pr22649-2b.so
mn10200-elf  +FAIL: ld-elf/pr24526
mn10200-elf  +FAIL: ld-elf/pr25021
nios2-linux  +FAIL: __patchable_function_entries section 2
nios2-linux  +FAIL: __patchable_function_entries section 3
nios2-linux  +FAIL: __patchable_function_entries section 4
nios2-linux  +FAIL: __patchable_function_entries section 5
nios2-linux  +FAIL: __patchable_function_entries section 6
pj-elf  +FAIL: ld-elf/pr24526
pj-elf  +FAIL: ld-elf/pr25021
pru-elf  +FAIL: ld-elf/pr24526
pru-elf  +FAIL: ld-elf/pr25021
s12z-elf  +FAIL: ld-elf/pr24526
s12z-elf  +FAIL: ld-elf/pr25021
shle-unknown-netbsdelf  +FAIL: incorrect linked-to symbols
shle-unknown-netbsdelf  +FAIL: __patchable_function_entries section 2
shle-unknown-netbsdelf  +FAIL: __patchable_function_entries section 3
shle-unknown-netbsdelf  +FAIL: __patchable_function_entries section 4
shle-unknown-netbsdelf  +FAIL: __patchable_function_entries section 5
shle-unknown-netbsdelf  +FAIL: __patchable_function_entries section 6
sh-linux  +FAIL: incorrect linked-to symbols
sh-linux  +FAIL: __patchable_function_entries section 2
sh-linux  +FAIL: __patchable_function_entries section 3
sh-linux  +FAIL: __patchable_function_entries section 4
sh-linux  +FAIL: __patchable_function_entries section 5
sh-linux  +FAIL: __patchable_function_entries section 6
sh-nto  +FAIL: incorrect linked-to symbols
sh-nto  +FAIL: __patchable_function_entries section 2
sh-nto  +FAIL: __patchable_function_entries section 3
sh-nto  +FAIL: __patchable_function_entries section 4
sh-nto  +FAIL: __patchable_function_entries section 5
sh-nto  +FAIL: __patchable_function_entries section 6
sh-rtems  +FAIL: incorrect linked-to symbols
sh-rtems  +FAIL: __patchable_function_entries section 2
sh-rtems  +FAIL: __patchable_function_entries section 3
sh-rtems  +FAIL: __patchable_function_entries section 4
sh-rtems  +FAIL: __patchable_function_entries section 5
sh-rtems  +FAIL: __patchable_function_entries section 6
xc16x-elf  +FAIL: linked-to section 1
xc16x-elf  +FAIL: linked-to section 2
xc16x-elf  +FAIL: linked-to section 3
xc16x-elf  +FAIL: __patchable_function_entries section 2
xc16x-elf  +FAIL: __patchable_function_entries section 3
xc16x-elf  +FAIL: __patchable_function_entries section 4
xc16x-elf  +FAIL: __patchable_function_entries section 5
xc16x-elf  +FAIL: __patchable_function_entries section 6
xgate-elf  +FAIL: ld-elf/pr24526
xgate-elf  +FAIL: ld-elf/pr25021
z80-elf  +FAIL: linked-to section 1
z80-elf  +FAIL: linked-to section 2
z80-elf  +FAIL: linked-to section 3
z80-elf  +FAIL: ld-elf/pr24526
z80-elf  +FAIL: ld-elf/pr25021
z80-elf  +FAIL: __patchable_function_entries section 2
z80-elf  +FAIL: __patchable_function_entries section 3
z80-elf  +FAIL: __patchable_function_entries section 4
z80-elf  +FAIL: __patchable_function_entries section 5
z80-elf  +FAIL: __patchable_function_entries section 6

-- 
Alan Modra
Australia Development Lab, IBM