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linker warnings on macOS XCode 14: ld: warning: -undefined dynamic_lookup may not work with chained fixups #16413

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garymm opened this issue Oct 6, 2022 · 3 comments
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linker warnings on macOS XCode 14: ld: warning: -undefined dynamic_lookup may not work with chained fixups #16413

garymm opened this issue Oct 6, 2022 · 3 comments
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P3 We're not considering working on this, but happy to review a PR. (No assignee) platform: apple team-Rules-CPP Issues for C++ rules type: bug

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@garymm
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garymm commented Oct 6, 2022

Description of the problem / feature request:

cc_binary built on MacOS with XCode 14 results in warnings link the following being printed:
ld: warning: -undefined dynamic_lookup may not work with chained fixups

Maybe due to this?

bazel/tools/osx/crosstool/cc_toolchain_config.bzl

Line 1130 in 32d56b6

flag_groups = [flag_group(flags = ["-undefined", "dynamic_lookup"])],

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

git clone https://github.com/bazelbuild/examples
cd examples/cpp-tutorial/stage3
bazel build //...

Output:

➜  bazel build //...
Starting local Bazel server and connecting to it...
INFO: Analyzed 3 targets (38 packages loaded, 172 targets configured).
INFO: Found 3 targets...
INFO: From Linking main/libhello-greet.so:
ld: warning: -undefined dynamic_lookup may not work with chained fixups
INFO: From Linking lib/libhello-time.so:
ld: warning: -undefined dynamic_lookup may not work with chained fixups
INFO: From Linking main/hello-world:
ld: warning: -undefined dynamic_lookup may not work with chained fixups

What operating system are you running Bazel on?

MacOS 12.6

What's the output of bazel info release?

release 5.3.1

What version of rules_cc do you use? Can you paste the workspace rule used to fetch rules_cc? What other relevant dependencies does your project have?

built in, but also tried 0.0.4

What Bazel options do you use to trigger the issue? What C++ toolchain do you use?

Didn't specify any bazel options or configure any custom toolchain.

Have you found anything relevant by searching the web?

python/cpython#97524
ruby/ruby#6193
https://issues.guix.gnu.org/issue/57849
@garymm garymm mentioned this issue Oct 6, 2022
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@keith
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keith commented Oct 6, 2022

As a temporary workaround you can pass --linkopt=-Wl,-no_fixup_chains to disable the chained fixup feature of the linker. AFAIUI that feature has runtime (or maybe just launch time) performance benefits, but it isn't otherwise required and only defaults to enabled on newer OS versions. I doubt this will ever change on the linker side given that -undefined dynamic_lookup says that it's deprecated (although it has said that for many years on some platforms). If there is a bazel specific fix here it's probably to remove the use of -undefined dynamic_lookup all together

keith added a commit to keith/bazel that referenced this issue Oct 6, 2022
@keith
Remove use of -undefined dynamic_lookup on darwin
65bc2a9 
This flag ignores undefined symbols at link time and forces them to be
looked up dynamically. This is incompatible with the newer fixup chains
macho format and theoretically shouldn't be necessary assuming your
dependencies are well defined.

Fixes bazelbuild#16413
@keith keith mentioned this issue Oct 6, 2022
Closed
keith added a commit to keith/bazel that referenced this issue Oct 6, 2022
@keith
Remove use of -undefined dynamic_lookup on darwin
f0b850f 
This flag ignores undefined symbols at link time and forces them to be
looked up dynamically. This is incompatible with the newer fixup chains
macho format and theoretically shouldn't be necessary assuming your
dependencies are well defined.

Fixes bazelbuild#16413
@garymm garymm mentioned this issue Oct 7, 2022
Closed
@skaji skaji mentioned this issue Oct 9, 2022
Closed
@oquenchil oquenchil added P3 We're not considering working on this, but happy to review a PR. (No assignee) platform: apple and removed untriaged labels Oct 26, 2022
@jsoref jsoref mentioned this issue Nov 1, 2022
Merged
@garymm garymm mentioned this issue Nov 10, 2022
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@garymm
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garymm commented Nov 10, 2022

From reading this, it seems like there are legitimate uses of this linker flag that don't have work-arounds.

@keith
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keith commented Nov 12, 2022

Yes there are definitely legit use cases, but I don't think it needs to be the default, since I believe most use cases are pretty specific scenarios

@traversaro traversaro mentioned this issue Dec 17, 2022
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@bzz bzz mentioned this issue Dec 22, 2022
Closed
siddharthab pushed a commit to bazel-contrib/toolchains_llvm that referenced this issue Jan 17, 2023
Fixes for macOS
b9ce6dc 
With newer versions of macOS, LLVM and Bazel, a few things have changed
and need to be accounted.

- Chained fixups is a new feature that generates a warning when dynamic
  lookup is used for undefined symbols. Bazel's default local toolchain
  has now removed the dynamic lookups. See
  bazelbuild/bazel#16413
- Bazel 6.0.0 onwards have started using @loader_path; we need to update
  the wrapper script to handle these options accordingly.
- Some basic test fixes for macOS M1 when an LLVM distribution is
  available, e.g. for LLVM version 15.0.0.
siddharthab pushed a commit to bazel-contrib/toolchains_llvm that referenced this issue Jan 17, 2023
Fixes for macOS
640f09d 
With newer versions of macOS, LLVM and Bazel, a few things have changed
and need to be accounted.

- Chained fixups is a new feature that generates a warning when dynamic
  lookup is used for undefined symbols. Bazel's default local toolchain
  has now removed the dynamic lookups. See
  bazelbuild/bazel#16413
- Bazel 6.0.0 onwards have started using @loader_path; we need to update
  the wrapper script to handle these options accordingly.
- Some basic test fixes for macOS M1 when an LLVM distribution is
  available, e.g. for LLVM version 15.0.0.
@siddharthab siddharthab mentioned this issue Jan 17, 2023
Merged
siddharthab pushed a commit to bazel-contrib/toolchains_llvm that referenced this issue Jan 17, 2023
Fixes for macOS
09c11eb 
With newer versions of macOS, LLVM and Bazel, a few things have changed
and need to be accounted.

- Chained fixups is a new feature that generates a warning when dynamic
  lookup is used for undefined symbols. Bazel's default local toolchain
  has now removed the dynamic lookups. See
  bazelbuild/bazel#16413
- Bazel 6.0.0 onwards have started using @loader_path; we need to update
  the wrapper script to handle these options accordingly.
- Some basic test fixes for macOS M1 when an LLVM distribution is
  available, e.g. for LLVM version 15.0.0.
siddharthab pushed a commit to bazel-contrib/toolchains_llvm that referenced this issue Jan 17, 2023
Fixes for macOS
d34eea3 
With newer versions of macOS, LLVM and Bazel, a few things have changed
and need to be accounted.

- Chained fixups is a new feature that generates a warning when dynamic
  lookup is used for undefined symbols. Bazel's default local toolchain
  has now removed the dynamic lookups. See
  bazelbuild/bazel#16413. However, the issue
  is a little more complex, so we keep it for now and document the
  ongoing resolution threads.
- Bazel 6.0.0 onwards have started using @loader_path; we need to update
  the wrapper script to handle these options accordingly.
- Some basic test fixes for macOS M1 when an LLVM distribution is
  available, e.g. for LLVM version 15.0.0.
siddharthab pushed a commit to bazel-contrib/toolchains_llvm that referenced this issue Jan 17, 2023
Fixes for macOS (#177)
1dc9b1b 
With newer versions of macOS, LLVM and Bazel, a few things have changed
and need to be accounted.

- Chained fixups is a new feature that generates a warning when dynamic
  lookup is used for undefined symbols. Bazel's default local toolchain
  has now removed the dynamic lookups (see
  bazelbuild/bazel#16413). However, the issue
  is a little more complex, so we keep it for now and document the
  ongoing resolution threads between Apple and the community.
- Bazel 6.0.0 onwards have started using @loader_path; we need to update
  the wrapper script to handle these options accordingly.
- Some basic test fixes for macOS M1 when an LLVM distribution is
  available, e.g. for LLVM version 15.0.0.
@pr0m1th3as pr0m1th3as mentioned this issue Feb 5, 2023
Closed
hvadehra pushed a commit that referenced this issue Feb 14, 2023
@keith @hvadehra
Remove use of -undefined dynamic_lookup on darwin
eb5a248 
This flag ignores undefined symbols at link time and forces them to be looked up dynamically. This is incompatible with the newer fixup chains macho format and theoretically shouldn't be necessary assuming your dependencies are well defined.

Fixes #16413

Closes #16414.

PiperOrigin-RevId: 501275674
Change-Id: I9240b2596ffea329ef55d3ad15e98635ba8839b6
rwooster pushed a commit to rwooster/bazel-toolchain that referenced this issue May 18, 2023
Fixes for macOS (bazel-contrib#177)
25ce656 
With newer versions of macOS, LLVM and Bazel, a few things have changed
and need to be accounted.

- Chained fixups is a new feature that generates a warning when dynamic
  lookup is used for undefined symbols. Bazel's default local toolchain
  has now removed the dynamic lookups (see
  bazelbuild/bazel#16413). However, the issue
  is a little more complex, so we keep it for now and document the
  ongoing resolution threads between Apple and the community.
- Bazel 6.0.0 onwards have started using @loader_path; we need to update
  the wrapper script to handle these options accordingly.
- Some basic test fixes for macOS M1 when an LLVM distribution is
  available, e.g. for LLVM version 15.0.0.
@rwooster rwooster mentioned this issue May 18, 2023
Open
@tkoeppe tkoeppe mentioned this issue May 22, 2023
Closed
@kersson kersson mentioned this issue Sep 4, 2023
Closed
@tkittel tkittel mentioned this issue Nov 6, 2023
Closed
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Remove use of -undefined dynamic_lookup on darwin keith/bazel
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@keith @garymm @oquenchil @ShreeM01