Commit Graph

75 Commits

Author SHA1 Message Date
Nico Weber 542d3b609d [mac/lld] Implement -why_load
This is useful for debugging why lld loads .o files it shouldn't load.
It's also useful for users of lld -- I've used ld64's version of this a
few times.

Differential Revision: https://reviews.llvm.org/D92496
2020-12-02 18:33:12 -05:00
Nico Weber e16c0a9a68 clang+lld: Improve clang+ld.darwinnew.lld interaction, pass -demangle
This patch:
- adds an ld64.lld.darwinnew symlink for lld, to go with f2710d4b57,
  so that `clang -fuse-ld=lld.darwinnew` can be used to test new
  Mach-O lld while it's in bring-up. (The expectation is that we'll
  remove this again once new Mach-O lld is the defauld and only Mach-O
  lld.)
- lets the clang driver know if the linker is lld (currently
  only triggered if `-fuse-ld=lld` or `-fuse-ld=lld.darwinnew` is
  passed). Currently only used for the next point, but could be used
  to implement other features that need close coordination between
  compiler and linker, e.g. having a diag for calling `clang++` instead
  of `clang` when link errors are caused by a missing C++ stdlib.
- lets the clang driver pass `-demangle` to Mach-O lld (both old and
  new), in addition to ld64
- implements -demangle for new Mach-O lld
- changes demangleItanium() to accept _Z, __Z, ___Z, ____Z prefixes
  (and updates one test added in D68014). Mach-O has an extra
  underscore for symbols, and the three (or, on Mach-O, four)
  underscores are used for block names.

Differential Revision: https://reviews.llvm.org/D91884
2020-11-24 08:51:58 -05:00
Jez Ng 21f831134c [lld-macho] Add very basic support for LTO
Just enough to consume some bitcode files and link them. There's more
to be done around the symbol resolution API and the LTO config, but I don't yet
understand what all the various LTO settings do...

Reviewed By: #lld-macho, compnerd, smeenai, MaskRay

Differential Revision: https://reviews.llvm.org/D90663
2020-11-10 12:19:28 -08:00
Jez Ng e4e673e75a [lld-macho] Implement support for PIC
* Implement rebase opcodes. Rebase opcodes tell dyld where absolute
  addresses have been encoded in the binary. If the binary is not loaded
  at its preferred address, dyld has to rebase these addresses by adding
  an offset to them.
* Support `-pie` and use it to test rebase opcodes.

This is necessary for absolute address references in dylibs, bundles etc
to work.

Reviewed By: #lld-macho, gkm

Differential Revision: https://reviews.llvm.org/D87199
2020-09-25 11:28:31 -07:00
Greg McGary 8f2c31f22b [lld-macho] handle options -search_paths_first, -search_dylibs_first
Differential Revision: https://reviews.llvm.org/D88054
2020-09-23 14:56:33 -07:00
Greg McGary 145ce86dba [lld-macho] handle option -headerpad_max_install_names
Differential Revision: https://reviews.llvm.org/D88064
2020-09-22 17:24:19 -07:00
Greg McGary 7afbf3192d [lld-macho] minimally handle option -dynamic
Stifle the warning for unimplemented option `-dyamic`, since it is already the default. Add `Config::staticLink` and skeletal support for altering the flag, but otherwise leave the option `-static` as hidden and its warning in place.

Differential Revision: https://reviews.llvm.org/D88045
2020-09-22 08:03:44 -07:00
Jez Ng 62b39b3a0c [lld-macho] Implement -all_load
Differential Revision: https://reviews.llvm.org/D86640
2020-08-26 19:21:17 -07:00
Jez Ng cf918c809b [lld-macho] Implement -ObjC
It's roughly like -force_load with some filtering.

Differential Revision: https://reviews.llvm.org/D86181
2020-08-26 19:20:55 -07:00
Jez Ng 7394460d87 [lld-macho] Handle TAPI and regular re-exports uniformly
The re-exports list in a TAPI document can either refer to other inlined
TAPI documents, or to on-disk files (which may themselves be TBD or
regular files.) Similarly, the re-exports of a regular dylib can refer
to a TBD file.

Differential Revision: https://reviews.llvm.org/D85404
2020-08-26 19:20:48 -07:00
Jez Ng e48d1262b8 [lld-macho] Support -rpath
Pretty straightforward; just emits LC_RPATH for dyld to consume.

Note that lld itself does not yet support dylib lookup via @rpath.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D85701
2020-08-12 19:50:28 -07:00
Greg McGary 49fb1c2e90 [lld-macho] improve handling of -platform_version
This improves the handling of `-platform_version` by addressing the FIXME in the code to process the arguments.

Reviewed By: int3, #lld-macho

Differential Revision: https://reviews.llvm.org/D81413
2020-08-10 18:47:16 -07:00
Jez Ng 22e6648a18 [lld-macho] Implement -headerpad
Tools like `install_name_tool` and `codesign` may modify the Mach-O
header and increase its size. The linker has to provide padding to make this
possible. This diff does that, plus sets its default value to 32 bytes (which
is what ld64 does).

Unlike ld64, however, we lay out our sections *exactly* `-headerpad` bytes from
the header, whereas ld64 just treats the padding requirement as a lower bound.
ld64 actually starts laying out the non-header sections in the __TEXT segment
from the end of the (page-aligned) segment rather than the front, so its
binaries typically have more than `-headerpad` bytes of actual padding.
We should consider implementing the same alignment behavior.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D84714
2020-07-30 14:29:31 -07:00
Jez Ng 9282d04e04 [lld-macho] Support lookup of dylibs in frameworks
Needed for testing Objective-C programs (since e.g. Core
Foundation is a framework)

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D83925
2020-07-26 12:46:46 -07:00
Greg McGary d50f44a2f7 [lld-macho] Handle framework search path, alongside library search path
Summary:
Add front-end support for `lld::macho::Configuration::frameworkSearchPath`.

Depends on D80582.

Reviewers: ruiu, pcc, MaskRay, smeenai, int3, Ktwu, alexshap, christylee

Reviewed By: int3

Subscribers: ormris, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80677
2020-06-17 20:41:28 -07:00
Saleem Abdulrasool fcdf7578aa lld: improve the `-arch` handling for MachO
Use the default target triple configured by the user to determine the
default architecture for `ld64.lld`.  Stash the architecture in the
configuration as when linking against TBDs, we will need to filter out
the symbols based upon the architecture.  Treat the Haswell slice as it
is equivalent to `x86_64` but with the extra Haswell extensions (e.g.
AVX2, FMA3, BMI1, etc).  This will make it easier to add new
architectures in the future.

This change also changes the failure mode where an invalid `-arch`
parameter will result in the linker exiting without further processing.
2020-06-08 11:04:19 -07:00
Jez Ng 55e9eb416e [lld-macho] Support -order_file
The order file indicates how input sections should be sorted within each
output section, based on the symbols contained within those sections.

This diff sets the stage for implementing and testing
`.subsections_via_symbols`, where we will break up InputSections by each
symbol and sort them more granularly.

Reviewed By: smeenai

Differential Revision: https://reviews.llvm.org/D79668
2020-05-19 07:46:57 -07:00
Jez Ng 87b6fd3e02 [lld-macho] Add support for creating and reading reexported dylibs
This unblocks the linking of real programs, since many core system
functions are only available as sub-libraries of libSystem.

Differential Revision: https://reviews.llvm.org/D79228
2020-05-12 07:52:03 -07:00
Jez Ng 62b8f32f76 [lld-macho][reland] Add support for emitting dylibs with a single symbol
This got reverted due to UBSAN errors in a diff lower in the stack,
which is being fixed in https://reviews.llvm.org/D79050. This diff is
otherwise identical to the original https://reviews.llvm.org/D76908
(which was committed in 9598778bd1 and reverted in b52bc2653b).

Differential Revision: https://reviews.llvm.org/D79051
2020-04-28 17:08:32 -07:00
Shoaib Meenai b52bc2653b Revert "[lld-macho] Add support for emitting dylibs with a single symbol"
This reverts commit 9598778bd1.

Reverting due to UBSan failures:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/40817/steps/check-lld%20ubsan/logs/stdio
2020-04-28 11:34:03 -07:00
Jez Ng 9598778bd1 [lld-macho] Add support for emitting dylibs with a single symbol
Summary:
Add logic for emitting the correct set of load commands and segments
when `-dylib` is passed.

I haven't gotten to implementing a real export trie yet, so we can only
emit a single symbol, but it's enough to replace the YAML test files
introduced in D76252.

Differential Revision: https://reviews.llvm.org/D76908
2020-04-27 13:33:46 -07:00
Jez Ng 060efd24c7 [lld-macho] Add basic support for linking against dylibs
This diff implements:

* dylib loading (much of which is being restored from @pcc and @ruiu's
  original work)
* The GOT_LOAD relocation, which allows us to load non-lazy dylib
  symbols
* Basic bind opcode emission, which tells `dyld` how to populate the GOT

Differential Revision: https://reviews.llvm.org/D76252
2020-04-21 13:43:19 -07:00
Fangrui Song 6acd300375 Reland D75382 "[lld] Initial commit for new Mach-O backend"
With a fix for http://lab.llvm.org:8011/builders/clang-cmake-armv8-lld/builds/3636

Also trims some unneeded dependencies.
2020-04-02 12:03:43 -07:00
Oliver Stannard af39151f3c Revert "[lld] Initial commit for new Mach-O backend"
This is causing buildbot failures on 32-bit hosts, for example:
http://lab.llvm.org:8011/builders/clang-cmake-armv8-lld/builds/3636

This reverts commit 03f43b3aca.
2020-04-02 13:23:30 +01:00
Jez Ng 03f43b3aca [lld] Initial commit for new Mach-O backend
Summary:
This is the first commit for the new Mach-O backend, designed to roughly
follow the architecture of the existing ELF and COFF backends, and
building off work that @ruiu and @pcc did in a branch a while back. Note
that this is a very stripped-down commit with the bare minimum of
functionality for ease of review. We'll be following up with more diffs
soon.

Currently, we're able to generate a simple "Hello World!" executable
that runs on OS X Catalina (and possibly on earlier OS X versions; I
haven't tested them). (This executable can be obtained by compiling
`test/MachO/relocations.s`.) We're mocking out a few load commands to
achieve this -- for example, we can't load dynamic libraries, but
Catalina requires binaries to be linked against `dyld`, so we hardcode
the emission of a `LC_LOAD_DYLIB` command. Other mocked out load
commands include LC_SYMTAB and LC_DYSYMTAB.

Differential Revision: https://reviews.llvm.org/D75382
2020-03-31 11:58:47 -07:00