Dont run ast borrowck on mir mode

[spastorino]

r? @nikomatsakis

[Mark-Simulacrum]

@bors try

[bors]

⌛️ Trying commit 48765de with merge b27d9cf...

[nikomatsakis]

Looks great. One nit.

[nikomatsakis]

Looks great. One nit.

[nikomatsakis]

Nit: I would do

assert!(match tcx.borrowck_mode() {
    BorrowckMode::Mir => false,
    BorrowckMode::Ast => true,
    // etc
});

i.e., spell out all the cases. That way, when we change the enum (as we plan to soon) we can be sure it is all correct.

[rust-highfive]

The job x86_64-gnu-llvm-3.9 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.

[00:18:06]    Compiling rustc_passes v0.0.0 (file:///checkout/src/librustc_passes)
[00:18:06] error: unused import: `rustc::session::config::BorrowckMode`
[00:18:06]   --> librustc_borrowck/borrowck/mod.rs:39:5
[00:18:06]    |
[00:18:06] 39 | use rustc::session::config::BorrowckMode;
[00:18:06]    |
[00:18:06]    = note: `-D unused-imports` implied by `-D warnings`
[00:18:06] 
[00:18:07] error: aborting due to previous error
[00:18:07] error: aborting due to previous error
[00:18:07] 
[00:18:07] error: Could not compile `rustc_borrowck`.
[00:18:07] 
[00:18:07] Caused by:
[00:18:07]   process didn't exit successfully: `/checkout/obj/build/bootstrap/debug/rustc --crate-name rustc_borrowck librustc_borrowck/lib.rs --color always --error-format json --crate-type dylib --emit=dep-info,link -C prefer-dynamic -C opt-level=2 -C metadata=b63ed12ca231f4e3 -C extra-filename=-b63ed12ca231f4e3 --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 graphviz=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/libgraphviz-6020508f01da724d.so --extern log=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/liblog-023d781fbd65d983.rlib --extern rustc=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/librustc-1dddb0fa9d8a512f.so --extern rustc_data_structures=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/librustc_data_structures-25582ce13d3618ea.so --extern rustc_errors=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/librustc_errors-e036f8f5b9204e52.so --extern rustc_mir=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/librustc_mir-8fc603afb8ea9b13.so --extern syntax=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/libsyntax-a1b02e0d020520ac.so --extern syntax_pos=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/libsyntax_pos-f36f6cb494d373be.so -L native=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/build/backtrace-sys-a59a4023b81a89b2/out -L native=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/build/miniz-sys-ea5907e223517cf2/out` (exit code: 101)
[00:18:19] error: build failed
[00:18:19] 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"
[00:18:19] expected success, got: exit code: 101
[00:18:19] expected success, got: exit code: 101
[00:18:19] thread 'main' panicked at 'cargo must succeed', bootstrap/compile.rs:1117:9
[00:18:19] travis_fold:end:stage0-rustc

[00:18:19] travis_time:end:stage0-rustc:start=1530815735888662491,finish=1530816541396870522,duration=805508208031


[00:18:19] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap build
[00:18:19] Build completed unsuccessfully in 0:13:37
[00:18:19] Makefile:28: recipe for target 'all' failed
[00:18:19] make: *** [all] Error 1

The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:01bde1eb
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
---
travis_time:end:0c94e1b0:start=1530816541999796236,finish=1530816542006246005,duration=6449769
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:0dee3931
$ head -30 ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers || true
head: cannot open ‘./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers’ for reading: No such file or directory
travis_fold:end:after_failure.4
travis_fold:start:after_failure.5
travis_time:start:13cfb675
$ 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]

Try build failed; this needs a fix before perf can go forward.

[Mark-Simulacrum]

Wait, no, I misinterpreted the log. Ignore previous message.

[Mark-Simulacrum]

Trying out the new bot:

@rust-timer build b27d9cf

[rust-timer]

Insufficient permissions to issue commands to rust-timer.

[Mark-Simulacrum]

@rust-timer build b27d9cf

[rust-timer]

Insufficient permissions to issue commands to rust-timer.

[Mark-Simulacrum]

@rust-timer build b27d9cf

[rust-timer]

Please provide the full 40 character commit hash.

[Mark-Simulacrum]

@rust-timer build b27d9cf

[rust-timer]

Bors try commit b27d9cf unexpectedly has 2 parents.

[Mark-Simulacrum]

@rust-timer build b27d9cf

[rust-timer]

Success: Queued b27d9cf with parent 94eb176, comparison URL.

[nikomatsakis]

@bors r+

[bors]

📌 Commit 25266c1 has been approved by nikomatsakis

[nnethercote]

This was a decent win for performance, speeding up several NLL benchmarks, the best by 9%:
99b0ddb...4f0ca92

We now have apples-to-apples comparisons between the old and new borrow checkers, and the NLL dashboard shows that the new borrow checker is substantially slower. "Check" builds of most benchmarks are at least 10% slower, and two (tuple-stress and html5ever) are still as much as 20x slower; html5ever also has very high memory usage. (#52028)