Check the invariant for principal inside the method

[oli-obk]

r? @Mark-Simulacrum

[rust-highfive]

The job x86_64-gnu-llvm-5.0 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.

[00:37:58] Compiling rustdoc v0.0.0 (/checkout/src/librustdoc)
[00:38:01] error[E0308]: mismatched types
[00:38:01] --> librustdoc/clean/mod.rs:2635:24
[00:38:01] |
[00:38:01] 2635 | if let Some(principal) = obj.principal() {
[00:38:01] | ^^^^^^^^^^^^^^^ expected struct `rustc::ty::Binder`, found enum `std::option::Option`
[00:38:01] |
[00:38:01] = note: expected type `rustc::ty::Binder<rustc::ty::ExistentialTraitRef<'_>>`
[00:38:01] 4057816 .
1798488 ./obj
1798448 ./obj/build
---
151484 ./obj/build/bootstrap/debug/incremental
151412 ./src/tools/clang
149120 ./src/llvm-emscripten/test
136028 ./obj/build/bootstrap/debug/incremental/bootstrap-3ivyub3ic2113
136024 ./obj/build/bootstrap/debug/incremental/bootstrap-3ivyub3ic2113/s-f5ohiaivx9-11os506-1vqgtfjdeq8xj
120432 ./obj/build/x86_64-unknown-linux-gnu/stage1-rustc/x86_64-unknown-linux-gnu/release
118224 ./obj/build/x86_64-unknown-linux-gnu/stage1-rustc/x86_64-unknown-linux-gnu/release/deps
111072 ./src/llvm/test/CodeGen
107656 ./obj/build/x86_64-unknown-linux-gnu/stage0/lib/rustlib/x86_64-unknown-linux-gnu/codegen-backends
---
41756 ./obj/build/x86_64-unknown-linux-gnu/stage0-rustc/rel425887465070062,duration=8750809
travis_fold:end:after_failure.4
travis_fold:start:after_failure.5
travis_time:start:1b3e6d38
$ 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:0ebc5d50
$ 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)

[Mark-Simulacrum]

This looks reasonable to me, presuming I've understood. To clarify, this is fine because all Dynamic (i.e. trait objects) are currently required to have a principal, right? If so, then r=me once tests are passing

[oli-obk]

To clarify, this is fine because all Dynamic (i.e. trait objects) are currently required to have a principal, right?

yes, the way you create such objects is by giving them a principal (If I'm reading the code correctly)

Also, like 10% of the code calling principal was unwrapping, all the rest was using if let with varying levels of "do something useful when it is None". The way it is now we'll at least notice if we change this invariant.

@bors r=Mark-Simulacrum

[bors]

📌 Commit 585490d has been approved by Mark-Simulacrum

[bors]

⌛ Testing commit 585490d with merge 87fceb15a7b91e37fb7c3df06ecda090b6af01bb...

[bors]

💔 Test failed - status-travis

[rust-highfive]

The job dist-mipsel-linux 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:02c4898c:start=1539499129794375056,finish=1539499129805258970,duration=10883914
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:1040bef0
$ ln -s . checkout && for CORE in obj/cores/core.*; do EXE=$(echo $CORE | sed 's|obj/cores/core\.[0-9]*\.!checkout!\(.*\)|\1|;y|!|/|'); if [ -f "$EXE" ]; then printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" "$CORE"; gdb --batch -q -c "$CORE" "$EXE" -iex 'set auto-load off' -iex 'dir src/' -iex 'set sysroot .' -ex bt -ex q; echo travis_fold":"end:crashlog; fi; done || true
travis_fold:end:after_failure.4
travis_fold:start:after_failure.5
travis_time:start:0934b7a4
travis_time:start:0934b7a4
$ 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:35329d23
$ 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)

[kennytm]

@bors retry travis-ci/travis-ci#9696

[bors]

⌛ Testing commit 585490d with merge 14f42a7...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: Mark-Simulacrum
Pushing 14f42a7 to master...

[rust-highfive]

📣 Toolstate changed by #55032!

Tested on commit 14f42a7.
Direct link to PR: #55032

💔 clippy-driver on windows: test-pass → build-fail (cc @Manishearth@llogiq@mcarton@oli-obk, @rust-lang/infra).
💔 clippy-driver on linux: test-pass → build-fail (cc @Manishearth@llogiq@mcarton@oli-obk, @rust-lang/infra).
💔 rls on windows: test-pass → build-fail (cc @nrc, @rust-lang/infra).
💔 rls on linux: test-pass → build-fail (cc @nrc, @rust-lang/infra).