f02cb05882
See https://sourceware.org/ml/binutils/2016-07/msg00091.html This patch stop --gc-sections elf_gc_sweep_symbol localizing symbols that ought to remain global. The difficulty with always descending into output section statements is that symbols defined by the script in such statements don't have a bfd section when lang_do_assignments runs early in the link process. There are two approaches to curing this problem. Either we can create the bfd section early, or we can use a special section. This patch takes the latter approach and uses bfd_und_section. (Creating bfd sections early results in changed output section order, and thus lots of testsuite failures. You can't create all output sections early to ensure proper ordering as KEEP then stops empty sections from being stripped.) The wrinkle with this approach is that some code that runs at gc-sections time needs to be made aware of the odd defined symbols using bfd_und_section. bfd/ * elf64-x86-64.c (elf_x86_64_convert_load_reloc): Handle symbols defined temporarily with bfd_und_section. * elflink.c (_bfd_elf_gc_keep): Don't set SEC_KEEP for bfd_und_section. * elfxx-mips.c (mips_elf_local_pic_function_p): Exclude defined symbols with bfd_und_section. ld/ * ldlang.c (lang_do_assignments_1): Descend into output section statements that do not yet have bfd sections. Set symbol section temporarily for symbols defined in such statements to the undefined section. Don't error on data or reloc statements until final phase. * ldexp.c (exp_fold_tree_1 <etree_assign>): Handle bfd_und_section in expld.section. * testsuite/ld-mmix/bpo-10.d: Adjust. * testsuite/ld-mmix/bpo-11.d: Adjust.
32 lines
895 B
Makefile
32 lines
895 B
Makefile
#source: start3.s
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#source: bpo-6.s
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#source: bpo-2.s
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#source: bpo-5.s
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#as: -linker-allocated-gregs
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#ld: -m elf64mmix --gc-sections
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#objdump: -st
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# Check that GC removes one of the three BPO:s, for the collected section.
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.*: file format elf64-mmix
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SYMBOL TABLE:
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0+ l d \.init 0+ (|\.init)
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0+10 l d \.text 0+ (|\.text)
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0+7e8 l d \.MMIX\.reg_contents 0+ (|\.MMIX\.reg_contents)
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0+ l df \*ABS\* 0+ .*
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0+ l \.init 0+ _start
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0+14 g \.text 0+ x
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0+10 g \.text 0+ x2
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2000000000000000 g \.text 0+ __bss_start
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2000000000000000 g \.text 0+ _edata
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2000000000000000 g \.text 0+ _end
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0+10 g \.text 0+ _start\.
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Contents of section \.init:
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0000 00000000 0000003d 00000000 0000003a .*
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Contents of section \.text:
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0010 232dfe00 232dfd00 .*
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Contents of section \.MMIX\.reg_contents:
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07e8 00000000 0000107c 00000000 0000a420 .*
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