Commit Graph

13 Commits

Author SHA1 Message Date
Keith Smiley 272bf0fc41
[lld-macho] Add support for exporting no symbols
As an optimization for ld64 sometimes it can be useful to not export any
symbols for top level binaries that don't need any exports, to do this
you can pass `-exported_symbols_list /dev/null`, or new with Xcode 14
(ld64 816) there is a `-no_exported_symbols` flag for the same behavior.
This reproduces this behavior where previously an empty exported symbols
list file would have been ignored.

Differential Revision: https://reviews.llvm.org/D127562
2022-06-15 15:07:27 -07:00
Vincent Lee 9f2272ff51 [lld-macho] Allow dead_strip to work with exported private extern symbols
It seems like we are overly asserting when running `-dead_strip` with
exported symbols. ld64 treats exported private extern symbols as a liveness
root. Loosen the assert to match ld64's behavior.

Reviewed By: #lld-macho, int3

Differential Revision: https://reviews.llvm.org/D124143
2022-04-22 18:45:27 -07:00
Jez Ng aa108fffec [lld-macho][nfc] Clean up trailing spaces and tabs 2022-02-15 21:33:26 -05:00
Jez Ng 4490a26a3e [lld-macho][nfc] Rename %no_fatal_warnings_lld in tests
... to use hyphens instead of underscores, making it consistent with
our other substitutions like %no-arg-lld and %lld-watchos.

Reviewed By: keith

Differential Revision: https://reviews.llvm.org/D119513
2022-02-11 10:06:38 -05:00
Vy Nguyen 9b29dae3ca [lld-macho] Allow exporting weak_def_can_be_hidden(AKA "autohide") symbols
autohide symbols behaves similarly to private_extern symbols.
However, LD64 allows exporting autohide symbols. LLD currently does not.
This patch allows LLD to export them.

Differential Revision: https://reviews.llvm.org/D113167
2021-11-12 21:57:30 -05:00
Jez Ng dc9ee39251 [lld-macho] Downgrade "cannot export hidden symbol" to warning
This matches ld64's behavior, and makes it easier to fit LLD
into existing build systems.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D107011
2021-07-28 18:46:26 -04:00
Jez Ng 2516b0b526 [lld-macho] Treat undefined symbols uniformly
In particular, we should apply the `-undefined` behavior to all
such symbols, include those that are specified via the command line
(i.e.  `-e`, `-u`, and `-exported_symbol`). ld64 supports this too.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D102143
2021-05-10 15:45:54 -04:00
Greg McGary 5be8502271 [lld-macho] Explicitly undefine literal exported symbols
Symbols explicitly exported via command-line options `--exported_symbol SYM` and `--exported_symbols_list FILE` must be defined. Before this fix, lazy symbols defined in archives would be left to languish. We now force them to be included in the linked output.

Differential Revision: https://reviews.llvm.org/D102100
2021-05-08 11:37:00 -07:00
Nico Weber de266ce4f9 [lld/mac] Don't assert when using -exported_symbol with private symbol
When I added this assert in D93609, it asserted that a symbol that
is privateExtern is also isExternal().

In D98381 the privateExtern check moved into shouldExportSymbol()
but the assert didn't -- now it checked that _every_ non-exported
symbol is isExternal(), which isn't true. Move the assert into the
privateExtern check where it used to be.

Fixes PR50098.

Differential Revision: https://reviews.llvm.org/D101223
2021-04-24 10:21:51 -04:00
Nico Weber 4ca0fbfabd [lld/mac] simplify export-options.s test a bit
- the macro seems needlessly clever -- shorter and imho clearer without it
- give all filenames an extension so they look like filenames
- rename .private_extern symbol from _private to _private_extern
  to prepare for follow-up that adds a truly private symbol

No behavior change.

Differential Revision: https://reviews.llvm.org/D101222
2021-04-24 08:03:55 -04:00
Jez Ng 53fd1ada76 [lld-macho] Fix typo in diagnostic message 2021-03-25 14:51:31 -04:00
Greg McGary db1e845a96 [lld-macho] Handle error cases properly for -exported_symbol(s_list)
This fixes defects in D98223 [lld-macho] implement options -(un)exported_symbol(s_list):
* disallow export of hidden symbols
* verify that whitelisted literal names are defined in the symbol table
* reflect export-status overrides in `nlist` attribute of `N_EXT` or `N_PEXT`

Thanks to @thakis for raising these issues

Differential Revision: https://reviews.llvm.org/D98381
2021-03-16 21:20:39 -07:00
Greg McGary 06c4aadeb6 [lld-macho] implement options -(un)exported_symbol(s_list)
Implement command-line options to alter a dylib's exported-symbols list:
* `-exported_symbol*` options override the default export list. The export list is compiled according to the command-line option(s) only.
* `-unexported_symbol*` options hide otherwise public symbols.
* `-*exported_symbol PATTERN` options specify a single literal or glob pattern.
* `-*exported_symbols_list FILE` options specify a file containing a series of lines containing symbol literals or glob patterns. Whitespace and `#`-prefix comments are stripped.

Note: This is a simple implementation of the primary use case. ld64 has much more complexity surrounding interactions with other options, many of which are obscure and undocumented. We will start simple and complexity as necessary.

Differential Revision: https://reviews.llvm.org/D98223
2021-03-09 18:43:39 -08:00