The ELF spec says
> If the sh_flags field for this section header includes the attribute SHF_INFO_LINK, then this member represents a section header table index.
Set SHF_INFO_LINK so that binary manipulation tools know that sh_info is
a section header table index instead of (the number of local symbols in the case of SHT_SYMTAB/SHT_DYNSYM).
We have already added SHF_INFO_LINK for --emit-relocs retained SHT_REL[A].
For example, we can teach llvm-objcopy to preserve the section index of the sh_info referenced section if
SHF_INFO_LINK is set. (GNU objcopy recognizes .rel[a].plt and updates
sh_info even if SHF_INFO_LINK is not set).
Reviewed By: grimar, psmith
Differential Revision: https://reviews.llvm.org/D89828
The DT_PLTRELSZ dynamic tag is calculated using the size of the
OutputSection containing the In.RelaPlt InputSection. This will work for the
default no linker script case and the majority of linker scripts.
Unfortunately it doesn't work for some 'almost' sensible linker scripts. It
is permitted by ELF to have a single OutputSection containing both
In.RelaDyn, In.RelaPlt and In.RelaIPlt. It is also permissible for the range
of memory [DT_RELA, DT_RELA + DT_RELASZ) and the range
[DT_JMPREL, DT_JMPREL + DT_JMPRELSZ) to overlap as long as the the latter
range is at the end.
To support this type of linker script use the specific InputSection sizes.
Fixes pr39678
Differential Revision: https://reviews.llvm.org/D54759
llvm-svn: 347736
Fangrui Song