Use a function to access the Hir map to be able to turn it into a query later

[Zoxc]

r? @eddyb

[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.

travis_time:end:02ce7dec:start=1543927771956780303,finish=1543927773346930256,duration=1390149953
$ 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
Setting environment variables from .travis.yml
$ export IMAGE=x86_64-gnu-llvm-5.0
---
[00:03:33] travis_fold:start:tidy
travis_time:start:tidy
tidy check
[00:03:34] tidy error: /checkout/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/region_name.rs:229: line longer than 100 chars
[00:03:34] tidy error: /checkout/src/librustc_privacy/lib.rs:384: line longer than 100 chars
[00:03:34] tidy error: /checkout/src/librustc_privacy/lib.rs:395: line longer than 100 chars
[00:03:35] some tidy checks failed
[00:03:35] [00:03:35] [00:03:35] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/tidy" "/checkout/src" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "--no-vendor" "--quiet"
[00:03:35] [00:03:35] [00:03:35] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test src/tools/tidy
[00:03:35] Build completed unsuccessfully in 0:00:55
[00:03:35] Build completed unsuccessfully in 0:00:55
[00:03:35] make: *** [tidy] Error 1
[00:03:35] Makefile:79: recipe for target 'tidy' failed
The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:011aae54
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
Tue Dec 4 12:53:17 UTC 2018
---
travis_time:end:049f65ba:start=1543927998009593717,finish=1543927998014769662,duration=5175945
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:0e4cdd72
$ 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:1b57c870
travis_time:start:1b57c870
$ 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:12bd0eff
$ 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)

[eddyb]

This PR LGTM as-is (cc @nikomatsakis@michaelwoerister).

---

FWIW, what I was envisioning long-term, would be something like tcx.hir(def_id) that gave you the HIR tree that owns that DefId (ideally that'd be 1:1, but we have more DefIds than ItemLocalId owners), and within which ItemLocalId could be used (which I'd call DefLocalHirId).

That is, everything would start from a DefId, whether it has a context to keep track of the "local HIR" it's in, or not, and we wouldn't expose the CrateNum/DefIndex distinction too much.

Among other things, this would allow us to avoid keeping the entire HIR in-memory all the time.

[bors]

☔ The latest upstream changes (presumably #56486) made this pull request unmergeable. Please resolve the merge conflicts.

[oli-obk]

Discussed in compiler meeting, no complaints, only cheering.

So I guess r=eddyb after a rebase

[oli-obk]

@bors p=1 super bitrotty PR

[Zoxc]

Protip for @rust-lang/dev-tools, search and replace tcx.hir with tcx.hir() =P

[Zoxc]

@bors r=eddyb

[bors]

📌 Commit a70babe has been approved by eddyb

[bors]

⌛ Testing commit a70babe with merge 4a45578...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: eddyb
Pushing 4a45578 to master...

[rust-highfive]

📣 Toolstate changed by #56502!

Tested on commit 4a45578.
Direct link to PR: #56502

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