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| author | Alan Modra <amodra@gmail.com> | 2021-03-01 08:22:49 +1030 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2021-03-01 17:28:03 +1030 |
| commit | 8ee10e86093150c70360d9e26b29e6d9b6398f33 (patch) | |
| tree | d9b022e21486a83064279ec452009a394b62a8b0 /ld/ld.texi | |
| parent | 7824c1d22fcab8a68162634d4293f4a6666ca43e (diff) | |
| download | gdb-8ee10e86093150c70360d9e26b29e6d9b6398f33.zip gdb-8ee10e86093150c70360d9e26b29e6d9b6398f33.tar.gz gdb-8ee10e86093150c70360d9e26b29e6d9b6398f33.tar.bz2 | |
PR27451, -z start_stop_gc
When --gc-sections is in effect, a reference from a retained section
to __start_SECNAME or __stop_SECNAME causes all input sections named
SECNAME to also be retained, if SECNAME is representable as a C
identifier and either __start_SECNAME or __stop_SECNAME is synthesized
by the linker. Add an option to disable that feature, effectively
ignoring any relocation that references a synthesized linker defined
__start_ or __stop_ symbol.
PR 27451
include/
* bfdlink.h (struct bfd_link_info): Add start_stop_gc.
bfd/
* elflink.c (_bfd_elf_gc_mark_rsec): Ignore synthesized linker
defined start/stop symbols when start_stop_gc.
(bfd_elf_gc_mark_dynamic_ref_symbol): Likewise.
(bfd_elf_define_start_stop): Don't modify ldscript_def syms.
* linker.c (bfd_generic_define_start_stop): Likewise.
ld/
* emultempl/elf.em: Handle -z start-stop-gc and -z nostart-stop-gc.
* lexsup.c (elf_static_list_options): Display help for them. Move
help for -z stack-size to here from elf_shlib_list_options. Add
help for -z start-stop-visibility and -z undefs.
* ld.texi: Document -z start-stop-gc and -z nostart-stop-gc.
* NEWS: Mention -z start-stop-gc.
* testsuite/ld-gc/start2.s,
* testsuite/ld-gc/start2.d: New test.
* testsuite/ld-gc/gc.exp: Run it.
Diffstat (limited to 'ld/ld.texi')
| -rw-r--r-- | ld/ld.texi | 17 |
1 files changed, 17 insertions, 0 deletions
@@ -1453,6 +1453,23 @@ Specify a stack size for an ELF @code{PT_GNU_STACK} segment. Specifying zero will override any default non-zero sized @code{PT_GNU_STACK} segment creation. +@item start-stop-gc +@itemx nostart-stop-gc +@cindex start-stop-gc +When @samp{--gc-sections} is in effect, a reference from a retained +section to @code{__start_SECNAME} or @code{__stop_SECNAME} causes all +input sections named @code{SECNAME} to also be retained, if +@code{SECNAME} is representable as a C identifier and either +@code{__start_SECNAME} or @code{__stop_SECNAME} is synthesized by the +linker. @samp{-z start-stop-gc} disables this effect, allowing +sections to be garbage collected as if the special synthesized symbols +were not defined. @samp{-z start-stop-gc} has no effect on a +definition of @code{__start_SECNAME} or @code{__stop_SECNAME} in an +object file or linker script. Such a definition will prevent the +linker providing a synthesized @code{__start_SECNAME} or +@code{__stop_SECNAME} respectively, and therefore the special +treatment by garbage collection for those references. + @item start-stop-visibility=@var{value} @cindex visibility @cindex ELF symbol visibility |