[PATCH] D85056: [ELF] Add --keep-section to expose linkerscript KEEP directive as a linker flag

[Peter Smith via Phabricator via llvm-commits]

psmith added a comment.

I do have some sympathy with wanting to use a command line option to keep an individual section from the command line as it has been useful in Arm's proprietary linker, although this is mainly due to the convenience of not having to create or modify another file.

One observation I'd make about the proposed implementation is that it looks like it only implements a subset of the Linker Script KEEP command that supports precise matches of a section name. Quoting from the GNU linker manual:

  When link-time garbage collection is in use (`--gc-sections'), it is often useful to mark sections that should not be eliminated. This is accomplished by surrounding an input section's wildcard entry with KEEP(), as in KEEP(*(.init)) or KEEP(SORT_BY_NAME(*)(.ctors)).

That permits the full power of the input section description to discriminate via object, as there can be many sections with the same name. Wildcards can sometimes be useful too.

I think it would be worth considering a richer interface for keep-sections. In Arm's proprietary linker we permitted a similar syntax as for the equivalent linker script. This did mean quoting or escaping parentheses but did provide equivalence in what could be achieved.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D85056/new/

https://reviews.llvm.org/D85056