Add inspection and setter methods to proc_macro::Diagnostic.

[SergioBenitez]

A few useful methods for proc_macro::Diagnostic.

r? @alexcrichton

[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.

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[SergioBenitez]

This is the build failure:

[00:23:33] error: This node does not have a stability attribute
[00:23:33]    --> libproc_macro/diagnostic.rs:130:31
[00:23:33]     |
[00:23:33] 130 |     pub fn children(&self) -> impl Iterator<Item = &Diagnostic> {
[00:23:33]     |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

...which doesn't make sense to me. The method is labeled unstable already:

#[unstable(feature = "proc_macro_diagnostic", issue = "38356")]
pub fn children(&self) -> impl Iterator<Item = &Diagnostic> { .. }

The error is pointing at the return type. Is there some extra labeling that needs to happen, or is this a bug elsewhere?

[alexcrichton]

Looks good to me! That may be a bug in the stability lint perhaps? It hasn't been touched in a long long time :(

[eddyb]

cc @oli-obk looks like the stability marking pass is not recursing into existential type nodes?

[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.

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[oli-obk]

Should be enough to add an arm to

rust/src/librustc/middle/stability.rs

Line 356 in a2af866

hir::ItemKind::Impl(.., None, _, _) | hir::ItemKind::ForeignMod(..) => {}

for ItemExistential(ExistTy { parent_fn_id: Some(_) }) which also skips the check_missing_stability call

[eddyb]

@oli-obk Isn't the problem here that sometimes it doesn't get marked?
This appears to be a problem specifically with -> impl Trait in inherent impl methods.

[oli-obk]

that's weird. Maybe lowering places them inside the impl block instead of the surrounding module?

[XAMPPRocky]

Triage: Marking this as blocked on a fix to the stability marking pass. @oli-obk Is there a PR/issue about this problem? If there's not can you open one?

[SergioBenitez]

@oli-obk Pinging to see if we can move this forward. Worst case, I'll just stop using impl Trait here.

[oli-obk]

Probably the same issue as #54045 where the same fix applies

[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.

[00:08:03]    Compiling proc_macro v0.0.0 (file:///checkout/src/libproc_macro)
[00:08:04] error: This node does not have a stability attribute
[00:08:04]    --> libproc_macro/diagnostic.rs:130:31
[00:08:04]     |
[00:08:04] 130 |     pub fn children(&self) -> impl Iterator<Item = &Diagnostic> {
[00:08:04] 
[00:08:04] error: aborting due to previous error
[00:08:04] 
[00:08:04] error: Could not compile `proc_macro`.
[00:08:04] error: Could not compile `proc_macro`.
[00:08:04] 
[00:08:04] Caused by:
[00:08:04]   process didn't exit successfully: `/checkout/obj/build/bootstrap/debug/rustc --crate-name proc_macro libproc_macro/lib.rs --color always --error-format json --crate-type dylib --emit=dep-info,link -C prefer-dynamic -C opt-level=2 -C metadata=87919c9c23cf3652 -C extra-filename=-87919c9c23cf3652 --out-dir /checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps --target x86_64-unknown-linux-gnu -L dependency=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps -L dependency=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/release/deps --extern rustc_data_structures=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/librustc_data_structures-05301c67193a930e.so --extern rustc_errors=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/librustc_errors-f4ac364f854372fe.so --extern syntax=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/libsyntax-0651ffc5a9129db1.so --extern syntax_pos=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/libsyntax_pos-47b99ffec2efbd05.so` (exit code: 1)
[00:08:04] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "build" "--target" "x86_64-unknown-linux-gnu" "-j" "4" "--release" "--locked" "--color" "always" "--features" " jemalloc" "--manifest-path" "/checkout/src/rustc/Cargo.toml" "--message-format" "json"
[00:08:04] expected success, got: exit code: 101
[00:08:04] thread 'main' panicked at 'cargo must succeed', bootstrap/compile.rs:1155:9
[00:08:04] travis_fold:end:stage0-rustc

[00:08:04] travis_time:end:stage0-rustc:start=1536818436003034068,finish=1536818574380296229,duration=138377262161


[00:08:04] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap build
[00:08:04] Build completed unsuccessfully in 0:03:17
[00:08:04] make: *** [all] Error 1
[00:08:04] Makefile:28: recipe for target 'all' failed

The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:00073bbd
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
---
travis_time:end:128be956:start=1536818575070752570,finish=1536818575075771607,duration=5019037
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:30eb2508
$ 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 -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:0970f98c
travis_time:start:0970f98c
$ 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:0f8ea352
$ 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)

[SergioBenitez]

Worked around the bug by using a special-cased Iterator type. Also added multispan support to boot.

[SergioBenitez]

@alexcrichton How does this look?

[alexcrichton]

@bors: r+

Looks good to me!

[bors]

📌 Commit 10bb5ed has been approved by alexcrichton

[bors]

⌛ Testing commit 10bb5ed with merge 5d083073c915a70b2049d9eed696bf31603e3557...

[bors]

💔 Test failed - status-travis

[rust-highfive]

The job arm-android 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.

[01:42:54] test time::tests::system_time_elapsed ... ok
[01:42:54] test time::tests::system_time_math ... ok
[01:42:59] test sync::mpsc::tests::stress_recv_timeout_two_threads ... ok
[01:43:01] test collections::hash::map::test_map::test_lots_of_insertions ... ok
[01:43:35] test process::tests::test_process_output_fail_to_start ... test process::tests::test_process_output_fail_to_start has been running for over 60 seconds
No output has been received in the last 30m0s, this potentially indicates a stalled build or something wrong with the build itself.
Check the details on how to adjust your build configuration on: https://docs.travis-ci.com/user/common-build-problems/#Build-times-out-because-no-output-was-received
The build has been terminated

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)

[SergioBenitez]

Failure looks unrelated. Rerun?

[kennytm]

@bors retry #43283

[bors]

⌛ Testing commit 10bb5ed with merge cba0fdf...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: alexcrichton
Pushing cba0fdf to master...