[beta] Permit unwinding through FFI by default

[cuviper]

Let's kick the can down the road, keeping FFI-unwind-abort out of stable until #58794 is resolved.

cc @rust-lang/release

[rust-highfive]

r? @varkor

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[rust-highfive]

⚠️ Warning ⚠️

• Pull requests are usually filed against the master branch for this repo, but this one is against beta. Please double check that you specified the right target!

[Mark-Simulacrum]

@bors r+ p=1

[bors]

📌 Commit bca3591 has been approved by Mark-Simulacrum

[rust-highfive]

The job x86_64-gnu-llvm-6.0 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

travis_time:end:1a0a61d7:start=1554233331634759545,finish=1554233422530485291,duration=90895725746
$ git checkout -qf FETCH_HEAD
travis_fold:end:git.checkout

Encrypted environment variables have been removed for security reasons.
See https://docs.travis-ci.com/user/pull-requests/#pull-requests-and-security-restrictions
$ export SCCACHE_BUCKET=rust-lang-ci-sccache2
$ export SCCACHE_REGION=us-west-1
$ export GCP_CACHE_BUCKET=rust-lang-ci-cache
Setting environment variables from .travis.yml
---
travis_time:start:test_incremental
Check compiletest suite=incremental mode=incremental (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
[01:22:17] 
[01:22:17] running 98 tests
[01:22:34] ...........................F....F.................................................................
[01:22:34] 
[01:22:34] ---- [incremental] incremental/hashes/function_interfaces.rs stdout ----
[01:22:34] 
[01:22:34] 
[01:22:34] error in revision `cfail2`: test compilation failed although it shouldn't!
[01:22:34] status: exit code: 1
[01:22:34] command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/incremental/hashes/function_interfaces.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--cfg" "cfail2" "-C" "incremental=/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/hashes/function_interfaces/function_interfaces.inc" "-Z" "incremental-verify-ich" "-Z" "incremental-queries" "--error-format" "json" "-Zui-testing" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/hashes/function_interfaces/a" "-Crpath" "-O" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-Z" "query-dep-graph" "-Zincremental-ignore-spans" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/hashes/function_interfaces/auxiliary"
[01:22:34] ------------------------------------------
[01:22:34] 
[01:22:34] ------------------------------------------
[01:22:34] stderr:
[01:22:34] stderr:
[01:22:34] ------------------------------------------
[01:22:34] {"message":"`MirBuilt(make_extern)` should be dirty but is not","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/incremental/hashes/function_interfaces.rs","byte_start":2817,"byte_end":2851,"line_start":99,"line_end":99,"column_start":1,"column_end":35,"is_primary":true,"text":[{"text":"pub extern \"C\" fn make_extern() {}","highlight_start":1,"highlight_end":35}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: `MirBuilt(make_extern)` should be dirty but is not\n  --> /checkout/src/test/incremental/hashes/function_interfaces.rs:99:1\n   |\nLL | pub extern \"C\" fn make_extern() {}\n   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n\n"}
[01:22:34] thread 'main' panicked at 'Some tests failed', src/tools/compiletest/src/main.rs:496:22
[01:22:34] 
[01:22:34] ------------------------------------------
[01:22:34] 
[01:22:34] 
[01:22:34] thread '[incremental] incremental/hashes/function_interfaces.rs' panicked at 'explicit panic', src/tools/compiletest/src/runtest.rs:3295:9
[01:22:34] note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
[01:22:34] 
[01:22:34] ---- [incremental] incremental/hashes/inherent_impls.rs stdout ----
[01:22:34] 
[01:22:34] error in revision `cfail2`: test compilation failed although it shouldn't!
[01:22:34] status: exit code: 1
[01:22:34] command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/incremental/hashes/inherent_impls.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--cfg" "cfail2" "-C" "incremental=/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/hashes/inherent_impls/inherent_impls.inc" "-Z" "incremental-verify-ich" "-Z" "incremental-queries" "--error-format" "json" "-Zui-testing" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/hashes/inherent_impls/a" "-Crpath" "-O" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-Z" "query-dep-graph" "-Zincremental-ignore-spans" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/hashes/inherent_impls/auxiliary"
[01:22:34] ------------------------------------------
[01:22:34] 
[01:22:34] ------------------------------------------
[01:22:34] stderr:
[01:22:34] stderr:
[01:22:34] ------------------------------------------
[01:22:34] {"message":"`MirBuilt(Foo::make_method_extern)` should be dirty but is not","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/incremental/hashes/inherent_impls.rs","byte_start":6595,"byte_end":6638,"line_start":268,"line_end":268,"column_start":5,"column_end":48,"is_primary":true,"text":[{"text":"    pub extern fn make_method_extern(&self) { }","highlight_start":5,"highlight_end":48}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: `MirBuilt(Foo::make_method_extern)` should be dirty but is not\n  --> /checkout/src/test/incremental/hashes/inherent_impls.rs:268:5\n   |\nLL |     pub extern fn make_method_extern(&self) { }\n   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n\n"}
[01:22:34] 
[01:22:34] ------------------------------------------
[01:22:34] 
[01:22:34] thread '[incremental] incremental/hashes/inherent_impls.rs' panicked at 'explicit panic', src/tools/compiletest/src/runtest.rs:3295:9
---
[01:22:34] test result: FAILED. 96 passed; 2 failed; 0 ignored; 0 measured; 0 filtered out
[01:22:34] 
[01:22:34] 
[01:22:34] 
[01:22:34] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/compiletest" "--compile-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib" "--run-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib" "--rustc-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "--src-base" "/checkout/src/test/incremental" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental" "--stage-id" "stage2-x86_64-unknown-linux-gnu" "--mode" "incremental" "--target" "x86_64-unknown-linux-gnu" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/usr/lib/llvm-6.0/bin/FileCheck" "--host-rustcflags" "-Crpath -O -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--target-rustcflags" "-Crpath -O -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--docck-python" "/usr/bin/python2.7" "--lldb-python" "/usr/bin/python2.7" "--gdb" "/usr/bin/gdb" "--quiet" "--llvm-version" "6.0.0\n" "--system-llvm" "--cc" "" "--cxx" "" "--cflags" "" "--llvm-components" "" "--llvm-cxxflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"
[01:22:34] 
[01:22:34] 
[01:22:34] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[01:22:34] Build completed unsuccessfully in 0:13:23
[01:22:34] Build completed unsuccessfully in 0:13:23
[01:22:34] Makefile:48: recipe for target 'check' failed
[01:22:34] make: *** [check] Error 1
The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:00db8232
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
Tue Apr  2 20:53:08 UTC 2019
---
travis_time:end:040292fd:start=1554238390721784541,finish=1554238390785616709,duration=63832168
travis_fold:end:after_failure.4
travis_fold:start:after_failure.5
travis_time:start:10c3df04
$ cat ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers || true
cat: ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers: No such file or directory
travis_fold:end:after_failure.5
travis_fold:start:after_failure.6
travis_time:start:2552a98e
$ dmesg | grep -i kill

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[cuviper]

Hmm, I'm not sure what to make of those failures -- both do involve toggling extern though.

[pietroalbini]

@bors r-

[cuviper]

OK, needed to revert commit b4a6f59 from #57770 too, which wasn't present last time in #58795.

r? @Mark-Simulacrum

[Mark-Simulacrum]

@bors r+

[bors]

📌 Commit dc68548 has been approved by Mark-Simulacrum

[bors]

⌛ Testing commit dc68548 with merge 4655b72...

[bors]

☀️ Test successful - checks-travis, status-appveyor
Approved by: Mark-Simulacrum
Pushing 4655b72 to beta...