stop considering location when computing outlives relationships #50593

nikomatsakis · 2018-05-10T02:26:17Z

This doesn't (yet?) use SEME regions, but it does ignore the location for outlives constraints. This makes (I believe) NLL significantly faster -- but we should do some benchmarks. It regresses the "get-default" family of use cases for NLL, which is a shame, but keeps the other benefits, and thus represents a decent step forward.

r? @pnkfelix

Instead of tracking the "cause" of each bit that gets added, try to recover that by walking outlives relationships. This is currently imprecise, since it ignores the "point" where the outlives relationship is incurred -- but that's ok, since we're about to stop considering that overall in a later commit. This does seem to affect one error message negatively, I didn't dig *too* hard to find out why.

nikomatsakis · 2018-05-10T02:26:47Z

I confess I've not fully run the tests locally btw, and certainly not since rebasing, so we'll see what Travis thinks. =) But at least src/test/ui --test-args nll was passing for a while.

Mark-Simulacrum · 2018-05-10T02:31:24Z

@bors try

bors · 2018-05-10T02:31:35Z

⌛ Trying commit 434d59a with merge 121e57e...

@pnkfelix

stop considering location when computing outlives relationships This doesn't (yet?) use SEME regions, but it does ignore the location for outlives constraints. This makes (I believe) NLL significantly faster -- but we should do some benchmarks. It regresses the "get-default" family of use cases for NLL, which is a shame, but keeps the other benefits, and thus represents a decent step forward. r? @pnkfelix

rust-highfive · 2018-05-10T02:39:52Z

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.


[00:05:11] travis_fold:start:tidy
travis_time:start:tidy
tidy check
[00:05:11] tidy error: /checkout/src/librustc_mir/borrow_check/nll/region_infer/mod.rs:844: line longer than 100 chars
[00:05:11] tidy error: /checkout/src/librustc_mir/borrow_check/nll/region_infer/values.rs:236: line longer than 100 chars
[00:05:13] some tidy checks failed
[00:05:13] 
[00:05:13] 
[00:05:13] 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"
[00:05:13] 
[00:05:13] 
[00:05:13] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test src/tools/tidy
[00:05:13] Build completed unsuccessfully in 0:02:12
[00:05:13] Build completed unsuccessfully in 0:02:12
[00:05:13] Makefile:79: recipe for target 'tidy' failed
[00:05:13] make: *** [tidy] Error 1

The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:0d94e020
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)

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)

bors · 2018-05-10T04:36:29Z

☀️ Test successful - status-travis
State: approved= try=True

nikomatsakis · 2018-05-10T10:11:45Z

@Mark-Simulacrum you gonna do a perf run?

rust-highfive · 2018-05-10T10:41:56Z

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.

[00:46:28] ....................................................................................................
[00:46:34] ....................................................................................................
[00:46:41] ....................................................................................................
[00:46:47] ....................................................................................................
[00:46:54] ..........................................i.........................................F...............
[00:47:06] .....................................ii.............................................................
[00:47:13] ....................................................................................................
[00:47:19] .................i....................................................................
[00:47:19] failures:
[00:47:19] failures:
[00:47:19] 
[00:47:19] ---- [ui (nll)] ui/nll/get_default.rs stdout ----
[00:47:19]  diff of stderr:
[00:47:19] 
[00:47:19] 4 LL |         match map.get() {
[00:47:19] 5    |               --- immutable borrow occurs here
[00:47:19] 6 ...
[00:47:19] - LL |                 map.set(String::new()); // Just AST errors here
[00:47:19] + LL |                 map.set(String::new()); // Ideally, this would not error.
[00:47:19] 8    |                 ^^^ mutable borrow occurs here
[00:47:19] 9 ...
[00:47:19] 10 LL | }
[00:47:19] 
[00:47:19] 11    | - immutable borrow ends he^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here
[00:47:19] +    |
[00:47:19] + note: borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 26:1...
[00:47:19] +   --> $DIR/get_default.rs:26:1
[00:47:19] +    |
[00:47:19] + LL | / fn ok(map: &mut Map) -> &String {
[00:47:19] + LL | |     loop {
[00:47:19] + LL | |         match map.get() {
[00:47:19] + LL | |             Some(v) => {
[00:47:19] + ...  |
[00:47:19] + LL | |     }
[00:47:19] + LL | | }
[00:47:19] + 
[00:47:19] + 
[00:47:19] + error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable (Mir)
[00:47:19] +   --> $DIR/get_default.rs:45:17
[00:47:19] +    |
[00:47:19] + LL |         match map.get() {
[00:47:19] +    |               --- immutable borrow occurs here
[00:47:19] 42 LL |             Some(v) => {
[00:47:19] 43 LL |                 map.set(String::new()); // Both AST and MIR error here
[00:47:19] 44    |                 ^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here
[00:47:19] 
[00:47:19] 46 LL |                 return v;
[00:47:19] 47    |                        - borrow later used here
[00:47:19] - error: aborting due to 4 previous errors
[00:47:19] - error: aborting due to 4 previous errors
[00:47:19] + error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable (Mir)
[00:47:19] +   --> $DIR/get_default.rs:51:17
[00:47:19] +    |
[00:47:19] + LL |         match map.get() {
[00:47:19] +    |               --- immutable borrow occurs here
[00:47:19] + ...
[00:47:19] + LL |                 map.set(String::new()); // Ideally, just AST would error here
[00:47:19] +    |                 ^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here
[00:47:19] +    |
[00:47:19] + note: borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 41:1...
[00:47:19] +   --> $DIR/get_default.rs:41:1
[00:47:19] +    |
[00:47:19] + LL | / fn err(map: &mut Map) -> &String {
[00:47:19] + LL | |     loop {
[00:47:19] + LL | |         match map.get() {
[00:47:19] + LL | |             Some(v) => {
[00:47:19] + ...  |
[00:47:19] + LL | |     }
[00:47:19] + LL | | }
[00:47:19] + 
[00:47:19] thread 'main' panicked at 'Some tests failed', tools/compiletest/src/main.rs:492:22
[00:47:19] + error: aborting due to 6 previous errors
[00:47:19] 50 
[00:47:19] 50 
[00:47:19] 51 For more information about this error, try `rustc --explain E0502`.
[00:47:19] 52 
[00:47:19] 
[00:47:19] 
[00:47:19] The actual stderr differed from the expected stderr.
[00:47:19] Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/nll/get_default.nll.stderr
[00:47:19] To update references, run this command from build directory:
[00:47:19] /checkout/src/test/ui/update-references.sh '/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui' 'nll/get_default.rs'
[00:47:19] error: 1 errors occurred comparing output.
[00:47:19] status: exit code: 101
[00:47:19] status: exit code: 101
[00:47:19] command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/nll/get_default.rs" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/nll/get_default.stage2-x86_64-unknown-linux-gnu" "-Zborrowck=mir" "-Ztwo-phase-borrows" "-Crpath" "-O" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-Zborrowck=compare" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/nll/get_default.stage2-x86_64-unknown-linux-gnu.aux" "-A" "unused"
[00:47:19] ------------------------------------------
[00:47:19] 
[00:47:19] ------------------------------------------
[00:47:19] stderr:
[00:47:19] stderr:
[00:47:19] ------------------------------------------
[00:47:19] {"message":"cannot borrow `*map` as mutable because it is also borrowed as immutable (Ast)","code":{"code":"E0502","explanation":"\nThis error indicates that you are trying to borrow a variable as mutable when it\nhas already been borrowed as immutable.\n\nExample of erroneous code:\n\n```compile_fail,E0502\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    let ref y = a; // a is borrowed as immutable.\n    bar(a); // error: cannot borrow `*a` as mutable because `a` is also borrowed\n            //        as immutable\n}\n```\n\nTo fix this error, ensure that you don't have any other references to the\nvariable before trying to access it mutably:\n\n```\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    bar(a);\n    let ref y = a; // ok!\n}\n```\n\nFor more information on the rust ownership system, take a look at\nhttps://doc.rust-lang.org/stable/book/references-and-borrowing.html.\n"},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1053,"byte_end":1056,"line_start":33,"limutable.\n\nExample of erroneous code:\n\n```compile_fail,E0502\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    let ref y = a; // a is borrowed as immutable.\n    bar(a); // error: cannot borrow `*a` as mutable because `a` is also borrowed\n            //        as immutable\n}\n```\n\nTo fix this error, ensure that you don't have any other references to the\nvariable before trying to access it mutably:\n\n```\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    bar(a);\n    let ref y = a; // ok!\n}\n```\n\nFor more information on the rust ownership system, take a look at\nhttps://doc.rust-lang.org/stable/book/references-and-borrowing.html.\n"},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1367,"byte_end":1370,"line_start":45,"line_end":45,"column_start":17,"column_end":20,"is_primary":true,"text":[{"text":"                map.set(String::new()); // Both AST and MIR error here","highlight_start":17,"highlight_end":20}],"label":"mutable borrow occurs here","suggested_replacement":null,"expansion":null},{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1314,"byte_end":1317,"line_start":43,"line_end":43,"column_start":15,"column_end":18,"is_primary":false,"text":[{"text":"        match map.get() {","highlight_start":15,"highlight_end":18}],"label":"immutable borrow occurs here","suggested_replacement":null,"expansion":null},{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1812,"byte_end":1813,"line_start":57,"line_end":57,"column_start":1,"column_end":2,"is_primary":false,"text":[{"text":"}","highlight_start":1,"highlight_end":2}],"label":"immutable borrow ends here","suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable (Ast)\n  --> /checkout/src/test/ui/nll/get_default.rs:45:17\n   |\nLL |         match map.get() {\n   |               --- immutable borrow occurs here\nLL |             Some(v) => {\nLL |                 map.set(String::new()); // Both AST and MIR error here\n   |                 ^^^ mutable borrow occurs here\n...\nLL | }\n   | - immutable borrow ends here\n\n"}
[00:47:19] {"message":"cannot borrow `*map` as mutable because it is also borrowed as immutable (Ast)","code":{"code":"E0502","explanation":"\nThis error indicates that you are trying to borrow a variable as mutable when it\nhas already been borrowed as immutable.\n\nExample of erroneous code:\n\n```compile_fail,E0502\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    let ref y = a; // a is borrowed as immutable.\n    bar(a); // error: cannot borrow `*a` as mutable because `a` is also borrowed\n            //        as immutable\n}\n```\n\nTo fix this error, ensure that you don't have any other references to the\nvariable before trying to access it mutably:\n\n```\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    bar(a);\n    let ref y = a; // ok!\n}\n```\n\nFor more information on the rust ownership system, take a look at\nhttps://doc.rust-lang.org/stable/book/references-and-borrowing.html.\n"},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1610,"byte_end":1613,"line_start":51,"line_end":51,"column_start":17,"column_end":20,"is_primary":true,"text":[{"text":"                map.set(String::new()); // Ideally, just AST would error here","highlight_start":17,"highlight_end":20}],"label":"mutable borrow occurs here","suggested_replacement":null,"expansion":null},{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1314,"byte_end":1317,"line_start":43,"line_end":43,"column_start":15,"column_end":18,"is_primary":false,"text":[{"text":"        match map.get() {","highlight_start":15,"highlight_end":18}],"label":"immutable borrow occurs here","suggested_replacement":null,"expansion":null},{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1812,"byte_end":1813,"line_start":57,"line_end":57,"column_start":1,"column_end":2,"is_primary":false,"text":[{"text":"}","highlight_start":1,"highlight_end":2}],"label":"immutable borrow ends here","suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable (Ast)\n  --> /checkout/src/test/ui/nll/get_default.rs:51:17\n   |\nLL |         match map.get() {\n   |               --- immutable borrow occurs here\n...\nLL |                 map.set(String::new()); // Ideally, just AST would error here\n   |                 ^^^ mutable borrow occurs here\n...\nLL | }\n   | - immutable borrow ends here\n\n"}
[00:47:19] {"message":"cannot borrow `*map` as mutable because it is also borrowed as immutable (Mir)","code":{"code":"E0502","explanation":"\nThis error indicates that you are trying to borrow a variable as mutable when it\nhas already been borrowed as immutable.\n\nExample of erroneous code:\n\n```compile_fail,E0502\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    let ref y = a; // a is borrowed as immutable.\n    bar(a); // error: cannot borrow `*a` as mutable because `a` is also borrowed\n            //        as immutable\n}\n```\n\nTo fix this error, ensure that you don't have any other references to the\nvariable before trying to access it mutably:\n\n```\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    bar(a);\n    let ref y = a; // ok!\n}\n```\n\nFor more information on the rust ownership system, take a look at\nhttps://doc.rust-lang.org/stable/book/references-and-borrowing.html.\n"},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1053,"byte_end":1075,"line_start":33,"line_end":33,"column_start":17,"column_end":39,"is_primary":true,"text":[{"text":"                map.set(String::new()); // Ideally, this would not error.","highlight_start":17,"highlight_end":39}],"label":"mutable borrow occurs here","suggested_replacement":null,"expansion":null},{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":938,"byte_end":941,"line_start":28,"line_end":28,"column_start":15,"column_end":18,"is_primary":false,"text":[{"text":"        match map.get() {","highlight_start":15,"highlight_end":18}],"label":"immutable borrow occurs here","suggested_replacement":null,"expansion":null}],"children":[{"message":"borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 26:1...","code":null,"level":"note","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":879,"byte_end":1252,"line_start":26,"line_end":39,"column_start":1,"column_end":2,"is_primary":true,"text":[{"text":"fn ok(map: &mut Map) -> &String {","highlight_start":1,"highlight_end":34},{"text":"    loop {","highlight_start":1,"highlight_end":11},{"text":"        match map.get() {","highlight_start":1,"highlight_end":26},{"text":"            Some(v) => {","highlight_start":1,"highlight_end":25},{"text":"                return v;","highlight_start":1,"highlight_end":26},{"text":"            }","highlight_start":1,"highlight_end":14},{"text":"            None => {","highlight_start":1,"highlight_end":22},{"text":"                map.set(String::new()); // Ideally, this would not error.","highlight_start":1,"highlight_end":74},{"text":"                //~^ ERROR borrowed as immutable (Ast)","highlight_start":1,"highlight_end":55},{"text":"                //~| ERROR borrowed as immutable (Mir)","highlight_start":1,"highlight_end":55},{"text":"            }","highlight_start":1,"highlight_end":14},{"text":"        }","highlight_start":1,"highlight_end":10},{"text":"    }","highlight_start":1,"highlight_end":6},{"text":"}","highlight_start":1,"highlight_end":2}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":null}],"rendered":"error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable (Mir)\n  --> /checkout/src/test/ui/nll/get_default.rs:33:17\n   |\nLL |         match map.get() {\n   |               --- immutable borrow occurs here\n...\nLL |                 map.set(String::new()); // Ideally, this would not error.\n   |                 ^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here\n   |\nnote: borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 26:1...\n  --> /checkout/src/test/ui/nll/get_default.rs:26:1\n   |\nLL | / fn ok(map: &mut Map) -> &String {\nLL | |     loop {\nLL | |         match map.get() {\nLL | |             Some(v) => {\n...  |\nLL | |     }\nLL | | }\n   | |_^\n\n"}
[00:47:19] {"message":"cannot borrow `*map` as mutable because it is also borrowed as immutable (Mir)","code":{"code":"E0502","explanation":"\nThis error indicates that you are trying to borrow a variable as mutable when it\nhas already been borrowed as immutable.\n\nExample of erroneous code:\n\n```compile_fail,E0502\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    let ref y = a; // a is borrowed as immutable.\n    bar(a); // error: cannot borrow `*a` as mutable because `a` is also borrowed\n            //        as immutable\n}\n```\n\nTo fix this error, ensure that you don't have any other references to the\nvariable before trying to access it mutably:\n\n```\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    bar(a);\n    let ref y = a; // ok!\n}\n```\n\nFor more information on the rust ownership system, take a look at\nhttps://doc.rust-lang.org/stable/book/references-and-borrowing.html.\n"},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1367,"byte_end":1389,"line_start":45,"line_end":45,"column_start":17,"column_end":39,"is_primary":true,"text":[{"text":"                map.set(String::new()); // Both AST and MIR error here","highlight_start":17,"highlight_end":39}],"label":"mutable borrow occurs here","suggested_replacement":null,"expansion":null},{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1314,"byte_end":1317,"line_start":43,"line_end":43,"column_start":15,"column_end":18,"is_primary":false,"text":[{"text":"        match map.get() {","highlight_start":15,"highlight_end":18}],"label":"immutable borrow occurs here","suggested_replacement":null,"expansion":null},{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1555,"byte_end":1556,"line_start":48,"line_end":48,"column_start":24,"column_end":25,"is_primary":false,"text":[{"text":"                return v;","highlight_start":24,"highlight_end":25}],"label":"borrow later used here","suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable (Mir)\n  --> /checkout/src/test/ui/nll/get_default.rs:45:17\n   |\nLL |         match map.get() {\n   |               --- immutable borrow occurs here\nLL |             Some(v) => {\nLL |                 map.set(String::new()); // Both AST and MIR error here\n   |                 ^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here\n...\nLL |                 return v;\n   |                        - borrow later used here\n\n"}
[00:47:19] {"message":"cannot borrow `*map` as mutable because it is also borrowed as immutable (Mir)","code":{"code":"E0502","explanation":"\nThis error indicates that you are trying to borrow a variable as mutable when it\nhas already been borrowed as immutable.\n\nExample of erroneous code:\n\n```compile_fail,E0502\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    let ref y = a; // a is borrowed as immutable.\n    bar(a); // error: cannot borrow `*a` as mutable because `a` is also borrowed\n            //        as immutable\n}\n```\n\nTo fix this error, ensure that you don't have any other references to the\nvariable before trying to access it mutably:\n\n```\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    bar(a);\n    let ref y = a; // ok!\n}\n```\n\nFor more information on the rust ownership system, take a look at\nhttps://doc.rust-lang.org/stable/book/references-and-borrowing.html.\n"},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1610,"byte_end":1632,"line_start":51,"line_end":51,"column_start":17,"column_end":39,"is_primary":true,"text":[{"text":"                map.set(String::new()); // Ideally, just AST would error here","highlight_start":17,"highlight_end":39}],"label":"mutable borrow occurs here","suggested_replacement":null,"expansion":null},{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1314,"byte_end":1317,"line_start":43,"line_end":43,"column_start":15,"column_end":18,"is_primary":false,"text":[{"text":"        match map.get() {","highlight_start":15,"highlight_end":18}],"label":"immutable borrow occurs here","suggested_replacement":null,"expansion":null}],"children":[{"message":"borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 41:1...","code":null,"level":"note","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1254,"byte_end":1813,"line_start":41,"line_end":57,"column_start":1,"column_end":2,"is_primary":true,"text":[{"text":"fn err(map: &mut Map) -> &String {","highlight_start":1,"highlight_end":35},{"text":"    loop {","highlight_start":1,"highlight_end":11},{"text":"        match map.get() {","highlight_start":1,"highlight_end":26},{"text":"            Some(v) => {","highlight_start":1,"highlight_end":25},{"text":"                map.set(String::new()); // Both AST and MIR error here","highlight_start":1,"highlight_end":71},{"text":"                //~^ ERROR borrowed as immutable (Mir)","highlight_start":1,"highlight_end":55},{"text":"                //~| ERROR borrowed as immutable (Ast)","highlight_start":1,"highlight_end":55},{"text":"                return v;","highlight_start":1,"highlight_end":26},{"text":"            }","highlight_start":1,"highlight_end":14},{"text":"            None => {","highlight_start":1,"highlight_end":22},{"text":"                map.set(String::new()); // Ideally, just AST would error here","highlight_start":1,"highlight_end":78},{"text":"                //~^ ERROR borrowed as immutable (Ast)","highlight_start":1,"highlight_end":55},{"text":"                //~| ERROR borrowed as immutable (Mir)","highlight_start":1,"highlight_end":55},{"text":"            }","highlight_start":1,"highlight_end":14},{"text":"        }","highlight_start":1,"highlight_end":10},{"text":"    }","highlight_start":1,"highlight_end":6},{"text":"}","highlight_start":1,"highlight_end":2}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":null}],"rendered":"error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable (Mir)\n  --> /checkout/src/test/ui/nll/get_default.rs:51:17\n   |\nLL |         match map.get() {\n   |               --- immutable borrow occurs here\n...\nLL |                 map.set(String::new()); // Ideally, just AST would error here\n   |                 ^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here\n   |\nnote: borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 41:1...\n  --> /checkout/src/test/ui/nll/get_default.rs:41:1\n   |\nLL | / fn err(map: &mut Map) -> &String {\nLL | |     loop {\nLL | |         match map.get() {\nLL | |             Some(v) => {\n...  |\nLL | |     }\nLL | | }\n   | |_^\n\n"}
[00:47:19] {"message":"aborting due to 6 previous errors","code":null,"level":"error","spans":[],"children":[],"rendered":"error: aborting due to 6 previous errors\n\n"}
[00:47:19] {"message":"For more information about this error, try `rustc --explain E0502`.","code":null,"level":"","spans":[],"children":[],"rendered":"For more information about this error, try `rustc --explain E0502`.\n"}
[00:47:19] ------------------------------------------
[00:47:19] 
[00:47:19] thread '[ui (nll)] ui/nll/get_default.rs' panicked at 'explicit panic', tools/compiletest/src/runtest.rs:3033:9
[00:47:19] note: Run with `RUST_BACKTRACE=1` for a backtrace.
---
[00:47:19] test result: FAILED. 1378 passed; 1 failed; 7 ignored; 0 measured; 0 filtered out
[00:47:19] 
[00:47:19] 
[00:47:19] 
[00:47:19] 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/ui" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui" "--stage-id" "stage2-x86_64-unknown-linux-gnu" "--mode" "ui" "--target" "x86_64-unknown-linux-gnu" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/usr/lib/llvm-3.9/bin/FileCheck" "--host-rustcflags" "-Crpath -O -Zunstable-options " "--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" "3.9.1\n" "--system-llvm" "--cc" "" "--cxx" "" "--cflags" "" "--llvm-components" "" "--llvm-cxxflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always" "--compare-mode" "nll"
[00:47:19] 
[00:47:19] 
[00:47:19] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[00:47:19] Build completed unsuccessfully in 0:03:47
[00:47:19] Build completed unsuccessfully in 0:03:47
[00:47:19] make: *** [check] Error 1
[00:47:19] Makefile:58: recipe for target 'check' failed

The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:0f0095a0
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)

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)

rust-highfive · 2018-05-10T14:55:22Z

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.

  Downloading https://files.pythonhosted.org/packages/b7/31/05c8d001f7f87f0f07289a5fc0fc3832e9a57f2dbd4d3b0fee70e0d51365/jmespath-0.9.3-py2.py3-none-any.whl
Collecting python-dateutil<3.0.0,>=2.1; python_version >= "2.7" (from botocore==1.10.17->awscli)
/usr/local/lib/python2.7/dist-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
  Downloading https://files.pythonhosted.org/packages/cf/f5/af2b09c957ace60dcfac112b669c45c8c97e32f94aa8b56da4c6d1682825/python_dateutil-2.7.3-py2.py3-none-any.whl (211kB)
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---
[01:02:48] ....................................................................................................
[01:03:00] ....................................................................................................
[01:03:08] ....................................................................................................
[01:03:16] ....................................................................................................
[01:03:24] ..........................................i........................................F................
[01:03:38] .....................................ii.............................................................
[01:03:47] ....................................................................................................
[01:03:55] .................i....................................................................
[01:03:55] failures:
[01:03:55] failures:
[01:03:55] 
[01:03:55] ---- [ui (nll)] ui/nll/get_default.rs stdout ----
[01:03:55]  diff of stderr:
[01:03:55] 
[01:03:55] 41    |               --- immutable borrow occurs here
[01:03:55] 42 ...
[01:03:55] 43 LL |                 map.set(String::new()); // Ideally, this would not error.
[01:03:55] -    |                 ^^^ mutable borrow occurs here
[01:03:55] +    |                 ^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here
[01:03:55] 45    |
[01:03:55] 46 note: borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 26:1...
[01:03:55] 
[01:03:55] 56    | |_^
[01:03:55] 57 
[01:03:55] 57 
[01:03:55] 58 error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable (Mir)
[01:03:55] +   --> $DIR/get_default.rs:45:17
[01:03:55] +    |
[01:03:55] + LL |         match map.get() {
[01:03:55] +    |               --- immutable borrow occurs here
[01:03:55] + LL |             Some(v) => {
[01:03:55] + LL |                 map.set(String::new()); // Both AST and MIR error here
[01:03:55] +    |                 ^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here
[01:03:55] + ...
[01:03:55] + LL |                 return v;
[01:03:55] +    |                        - borrow later used here
[01:03:55] + 
[01:03:55] + error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable (Mir)
[01:03:55] 60    |
[01:03:55] 60    |
[01:03:55] 61 LL |         match map.get() {
[01:03:55] 
[01:03:55] 62    |               --- immutable borrow occurs here
[01:03:55] 63 ...
[01:03:55] 64 LL |                 map.set(String::new()); // Ideally, just AST would error here
[01:03:55] -    |                 ^^^ mutable borrow occurs here
[01:03:55] +    |                 ^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here
[01:03:55] 66    |
[01:03:55] 67 note: borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 41:1...
[01:03:55] 
[01:03:55] 
[01:03:55] 75 LL | |     }
[01:03:55] 76 LL | | }
[01:03:55] - 
[01:03:55] - 
[01:03:55] - error[E0502]: cannot borrow `*mapt/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-Zborrowck=compare" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/nll/get_default.stage2-x86_64-unknown-linux-gnu.aux" "-A" "unused"
[01:03:55] ------------------------------------------
[01:03:55] 
[01:03:55] ------------------------------------------
[01:03:55] stderr:
[01:03:55] stderr:
[01:03:55] ------------------------------------------
[01:03:55] {"message":"cannot borrow `*map` as mutable because it is also borrowed as immutable (Ast)","code":{"code":"E0502","explanation":"\nThis error indicates that you are trying to borrow a variable as mutable when it\nhas already been borrowed as immutable.\n\nExample of erroneous code:\n\n```compile_fail,E0502\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    let ref y = a; // a is borrowed as immutable.\n    bar(a); // error: cannot borrow `*a` as mutable because `a` is also borrowed\n            //        as immutable\n}\n```\n\nTo fix this error, ensure that you don't have any other references to the\nvariable before trying to access it mutably:\n\n```\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    bar(a);\n    let ref y = a; // ok!\n}\n```\n\nFor more information on the rust ownership system, take a look at\nhttps://doc.rust-lang.org/stable/book/references-and-borrowing.html.\n"},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1053,"byte_end":1056,"line_start":33,"line_end":33,"column_start":17,"column_end":20,"is_primary":true,"text":[{"text":"                map.set(String::new()); // Ideally, this would not error.","highlight_start":17,"herror: cannot borrow `*a` as mutable because `a` is also borrowed\n            //        as immutable\n}\n```\n\nTo fix this error, ensure that you don't have any other references to the\nvariable before trying to access it mutably:\n\n```\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    bar(a);\n    let ref y = a; // ok!\n}\n```\n\nFor more information on the rust ownership system, take a look at\nhttps://doc.rust-lang.org/stable/book/references-and-borrowing.html.\n"},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1367,"byte_end":1370,"line_start":45,"line_end":45,"column_start":17,"column_end":20,"is_primary":true,"text":[{"text":"                map.set(String::new()); // Both AST and MIR error here","highlight_start":17,"highlight_end":20}],"label":"mutable borrow occurs here","suggested_replacement":null,"expansion":null},{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1314,"byte_end":1317,"line_start":43,"line_end":43,"column_start":15,"column_end":18,"is_primary":false,"text":[{"text":"        match map.get() {","highlight_start":15,"highlight_end":18}],"label":"immutable borrow occurs here","suggested_replacement":null,"expansion":null},{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1812,"byte_end":1813,"line_start":57,"line_end":57,"column_start":1,"column_end":2,"is_primary":false,"text":[{"text":"}","highlight_start":1,"highlight_end":2}],"label":"immutable borrow ends here","suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error[E0502]: cannot borrow `*map` as mutable because it is also borrowed asuse `a` is also borrowed\n            //        as immutable\n}\n```\n\nTo fix this error, ensure that you don't have any other references to the\nvariable before trying to access it mutably:\n\n```\nfn bar(x: &mut i32) {}\nfn foo(a: &mut i32) {\n    bar(a);\n    let ref y = a; // ok!\n}\n```\n\nFor more information on the rust ownership system, take a look at\nhttps://doc.rust-lang.org/stable/book/references-and-borrowing.html.\n"},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":1053,"byte_end":1075,"line_start":33,"line_end":33,"column_start":17,"column_end":39,"is_primary":true,"text":[{"text":"                map.set(String::new()); // Ideally, this would not error.","highlight_start":17,"highlight_end":39}],"label":"mutable borrow occurs here","suggested_replacement":null,"expansion":null},{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":938,"byte_end":941,"line_start":28,"line_end":28,"column_start":15,"column_end":18,"is_primary":false,"text":[{"text":"        match map.get() {","highlight_start":15,"highlight_end":18}],"label":"immutable borrow occurs here","suggested_replacement":null,"expansion":null}],"children":[{"message":"borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 26:1...","code":null,"level":"note","spans":[{"file_name":"/checkout/src/test/ui/nll/get_default.rs","byte_start":879,"byte_end":1252,"line_start":26,"line_end":39,"column_start":1,"column_end":2,"is_primary":true,"text":[{"text":"fn ok(map: &mut Map) -> &String {","highlight_start":1,"highlight_end":34},{"text":"    loop {","highlight_starow occurs here\n   |\nnote: borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 41:1...\n  --> /checkout/src/test/ui/nll/get_default.rs:41:1\n   |\nLL | / fn err(map: &mut Map) -> &String {\nLL | |     loop {\nLL | |         match map.get() {\nLL | |             Some(v) => {\n...  |\nLL | |     }\nLL | | }\n   | |_^\n\n"}
[01:03:55] {"message":"aborting due to 6 previous errors","code":null,"level":"error","spans":[],"children":[],"rendered":"error: aborting due to 6 previous errors\n\n"}
[01:03:55] {"message":"For more information about this error, try `rustc --explain E0502`.","code":null,"level":"","spans":[],"children":[],"rendered":"For more information about this error, try `rustc --explain E0502`.\n"}
[01:03:55] ------------------------------------------
[01:03:55] 
[01:03:55] thread '[ui (nll)] ui/nll/get_default.rs' panicked at 'explicit panic', tools/compiletest/src/runtest.rs:3033:9
[01:03:55] note: Run with `RUST_BACKTRACE=1` for a backtrace.
---
[01:03:55] 
[01:03:55] thread 'main' panicked at 'Some tests failed', tools/compiletest/src/main.rs:492:22
[01:03:55] 
[01:03:55] 
[01:03:55] 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/lt=1525964117704774564,finish=1525964117753449699,duration=48675135
The command "date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
" exited with 0.
travis_fold:start:after_failure.1
travis_time:start:23470d5d

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)

rust-highfive · 2018-05-10T16:35:24Z

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.

[00:51:17] ---- [run-pass] run-pass/nll/get_default.rs stdout ----
[00:51:17]  
[00:51:17] error: compilation failed!
[00:51:17] status: exit code: 101
[00:51:17] command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/run-pass/nll/get_default.rs" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/run-pass" "--target=x86_64-unknown-linux-gnu" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/run-pass/nll/get_default.stage2-x86_64-unknown-linux-gnu" "-Crpath" "-O" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/run-pass/nll/get_default.stage2-x86_64-unknown-linux-gnu.aux"
[00:51:17] ------------------------------------------
[00:51:17] 
[00:51:17] ------------------------------------------
[00:51:17] stderr:
[00:51:17] stderr:
[00:51:17] ------------------------------------------
[00:51:17] error[E0499]: cannot borrow `*map` as mutable more than once at a time
[00:51:17]    |
[00:51:17]    |
[00:51:17] 16 |     match map.get_mut(&key) {
[00:51:17]    |           --- first mutable borrow occurs here
[00:51:17] ...
[00:51:17] 19 |             map.insert(key, "".to_string());
[00:51:17]    |             ^^^ second mutable borrow occurs here
[00:51:17]    |
[00:51:17] note: borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 15:1...
[00:51:17]    |
[00:51:17]    |
[00:51:17] 15 | / fn get_default(map: &mut HashMap<usize, String>, key: usize) -> &mut String {
[00:51:17] 16 | |     match map.get_mut(&key) {
[00:51:17] 17 | |         Some(value) => value,
[00:51:17] ...  |
[00:51:17] 22 | |     }
[00:51:17] 23 | | }
[00:51:17]    | |_^
[00:51:17]    | |_^
[00:51:17] 
[00:51:17] error[E0499]: cannot borrow `*map` as mutable more than once at a time
[00:51:17]    |
[00:51:17]    |
[00:51:17] 16 |     match map.get_mut(&key) {
[00:51:17]    |           --- first mutable borrow occurs here
[00:51:17] ...
[00:51:17] 20 |             map.get_mut(&key).unwrap()
[00:51:17]    |             ^^^ second mutable borrow occurs here
[00:51:17]    |
[00:51:17] note: borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 15:1...
[00:51:17]    |
[00:51:17]    |
[00:51:17] 15 | / fn get_default(map: &mut HashMap<usize, String>, key: usize) -> &mut String {
[00:51:17] 16 | |     match map.get_mut(&key) {
[00:51:17] 17 | |         Some(value) => value,
[00:51:17] ...  |
[00:51:17] 22 | |     }
[00:51:17] 23 | | }
[00:51:17]    | |_^
---
[00:51:17] 
[00:51:17] thread 'main' panicked at 'Some tests failed', tools/compiletest/src/main.rs:492:22
[00:51:17] 
[00:51:17] 
[00:51:17] 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/run-pass" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/run-pass" "--stage-id" "stage2-x86_64-unknown-linux-gnu" "--mode" "run-pass" "--target" "x86_64-unknown-linux-gnu" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/usr/lib/llvm-3.9/bin/FileCheck" "--host-rustcflags" "-Crpath -O -Zunstable-options " "--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" "3.9.1\n" "--system-llvm" "--cc" "" "--cxx" "" "--cflags" "" "--llvm-components" "" "--llvm-cxxflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"
[00:51:17] 
[00:51:17] 
[00:51:17] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[00:51:17] Build completed unsuccessfully in 0:12:30
[00:51:17] Build completed unsuccessfully in 0:12:30
[00:51:17] Makefile:58: recipe for target 'check' failed
[00:51:17] make: *** [check] Error 1

The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:229e8fd0
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)

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)

It no longer passes, and the ui test subsumes it anyhow.

rust-highfive · 2018-05-10T20:55:28Z

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.

travis_time:start:test_mir-opt
Check compiletest suite=mir-opt mode=mir-opt (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
[01:03:31] 
[01:03:31] running 50 tests
[01:03:52] thread 'main' panicked at 'Some tests failed', tools/compiletest/src/main.rs:492:22
[01:03:52] ...................................F..............
[01:03:52] 
[01:03:52] ---- [mir-opt] mir-opt/nll/region-liveness-two-disjoint-uses.rs stdout ----
[01:03:52] ---- [mir-opt] mir-opt/nll/region-liveness-two-disjoint-uses.rs stdout ----
[01:03:52]  thread '[mir-opt] mir-opt/nll/region-liveness-two-disjoint-uses.rs' panicked at 'Did not find expected line, error: ran out of mir dump to match against
[01:03:52] Expected Line: "| \'_#2r    | {bb2[0..=1], bb3[0..=1]}"
[01:03:52] Test Name: rustc.main.nll.0.mir
[01:03:52] Expected:
[01:03:52] ... (elided)
[01:03:52] | '_#2r    | {bb2[0..=1], bb3[0..=1]}
[01:03:52] ... (elided)
[01:03:52] | '_#4r    | {bb8[1..=4]}
[01:03:52] | '_#5r    | {bb2[1], bb3[0..=1], bb8[2..=4]}
[01:03:52] ... (elided)
[01:03:52] let mut _2: &'_#5r usize;
[01:03:52] ... (elided)
[01:03:52] _2 = &'_#2r _1[_3];
[01:03:52] ... (elided)
[01:03:52] _2 = &'_#4r (*_10);
[01:03:52] Actual:
[01:03:52] | Free Region Mapping
[01:03:52] | '_#0r    | Global   | ['_#0r, '_#1r]
[01:03:52] | '_#1r    | Local    | ['_#1r]
                                 | Live variables on entry to bb0[5]: [_1, _3]
[01:03:52]         _4 = Len(_1);
[01:03:52]                                          | Live variables on entry to bb0[6]: [_1, _3, _4]
[01:03:52]         _5 = Lt(_3, _4);
[01:03:52]                                          | Live variables on entry to bb0[7]: [_1, _3, _4, _5]
[01:03:52]         assert(move _5, "index out of bounds: the len is move _4 but the index is _3") -> [success: bb2, unwind: bb1];
[01:03:52]     }
[01:03:52]     | Live variables on entry to bb1: []
[01:03:52]     bb1: {
[01:03:52]                                          | Live variables on entry to bb1[0]: []
[01:03:52]         resume;
[01:03:52]     }
[01:03:52]     | Live variables on entry to bb2: [_1, _3]
[01:03:52]     bb2: {                              
[01:03:52]                                          | Live variables on entry to bb2[0]: [_1, _3]
[01:03:52]         _2 = &'_#2r _1[_3];
[01:03:52]                                          | Live variables on entry to bb2[1]: [_1, _2]
[01:03:52]         switchInt(const true) -> [false: bb4, otherwise: bb3];
[01:03:52]     }
[01:03:52]     | Live variables on entry to bb3: [_1, _2]
[01:03:52]     bb3: {                              
[01:03:52]                                          | Live variables on entry to bb3[0]: [_1, _2]
[01:03:52]         StorageLive(_8);
[01:03:52]                                          | Live variables on entry to bb3[1]: [_1, _2]
[01:03:52]         _8 = (*_2);
[01:03:52]                                          | Live variables on entry to bb3[2]: [_1, _8]
[01:03:52]         _7 = const use_x(move _8) -> [return: bb5, unwind: bb1];
[01:03:52]     }
[01:03:52]     | Live variables on entry to bb4: [_1]
[01:03:52]     bb4: {                              
[01:03:52]                                          | Live variables on entry to bb4[0]: [_1]
[01:03:52]         _9 = const use_x(const 22usize) -> [return: bb6, unwind: bb1];
[01:03:52]     }
[01:03:52]     | Live variables on entry to bb5: [_1]
[01:03:52]     bb5: {                              
[01:03:52]                                          | Live variables on entry to bb5[0]: [_1]
[01:03:52]         StorageDead(_8);
[01:03:52]                                          | Live variables on entry to bb5[1]: [_1]
[01:03:52]         _6 = ();
[01:03:52]                                          | Live variables on entry to bb5[2]: [_1]
[01:03:52]         goto -> bb7;
[01:03:52]     }
[01:03:52]     | Live variables on entry to bb6: [_1]
[01:03:52]     bb6: {                              
[01:03:52]                                          | Live variables on entry to bb6[0]: [_1]
[01:03:52]         _6 = ();
[01:03:52]                                          | Live variables on entry to bb6[1]: [_1]
[01:03:52]         goto -> bb7;
[01:03:52]     }
[01:03:52]     | Live variables on entry to bb7: [_1]
[01:03:52]     bb7: {                              
[01:03:52]                                          | Live variables on entry to bb7[0]: [_1]
[01:03:52]         StorageLive(_10);
[01:03:52]                                          | Live variables on entry to bb7[1]: [_1]
[01:03:52]         StorageLive(_11);
[01:03:52]                                          | Live variables on entry to bb7[2]: [_1]
[01:03:52]         _11 = const 1usize;
[01:03:52]                                          | Live variables on entry to bb7[3]: [_1, _11]
[01:03:52]         _12 = Len(_1);
[01:03:52]                                          | Live variables on entry to bb7[4]: [_1, _11, _12]
[01:03:52]         _13 = Lt(_11, _12);
[01:03:52]                                          | Live variables on entry to bb7[5]: [_1, _11, _12, _13]
[01:03:52]         assert(move _13, "index out of bounds: the len is move _12 but the index is _11") -> [success: bb8, unwind: bb1];
[01:03:52]     }
[01:03:52]     | Live variables on entry to bb8: [_1, _11]
[01:03:52]     bb8: {                              
[01:03:52]                                          | Live variables on entry to bb8[0]: [_1, _11]
[01:03:52]         _10 = &'_#3r _1[_11];
[01:03:52]                                          | Live variables on entry to bb8[1]: [_10]
[01:03:52]         _2 = &'_#4r (*_10);
[01:03:52]                                          | Live variables on entry to bb8[2]: [_2]
[01:03:52]         StorageDead(_10);
[01:03:52]                                          | Live variables on entry to bb8[3]: [_2]
[01:03:52]         StorageLive(_15);
[01:03:52]                                          | Live variables on entry to bb8[4]: [_2]
[01:03:52]         _15 = (*_2);
[01:03:52]                                          | Live variables on entry to bb8[5]: [_15]
[01:03:52]         _14 = const use_x(move _15) -> [return: bb9, unwind: bb1];
[01:03:52]     }
[01:03:52]     | Live variables on entry to bb9: []
[01:03:52]     bb9: {                              
[01:03:52]                                          | Live variables on entry to bb9[0]: []
[01:03:52]         StorageDead(_15);
[01:03:52]                                          | Live variables on entry to bb9[1]: []
[01:03:52]         _0 = ();
[01:03:52]                                          | Live variables on entry to bb9[2]: []
[01:03:52]         nop;
[01:03:52]                                          | Live variables on entry to bb9[3]: []
[01:03:52]         StorageDead(_2);
[01:03:52]                                          | Live variables on entry to bb9[4]: []
[01:03:52]         StorageDead(_1);
[01:03:52]                                          | Live variables on entry to bb9[5]: []
[01:03:52]         return;
[01:03:52] }', tools/compiletest/src/runtest.rs:2801:13
[01:03:52] note: Run with `RUST_BACKTRACE=1` for a backtrace.
[01:03:52] 
[01:03:52] 
[01:03:52] 
[01:03:52] failures:
[01:03:52]     [mir-opt] mir-opt/nll/region-liveness-two-disjoint-uses.rs
[01:03:52] 
[01:03:52] test result: FAILED. 49 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out
[01:03:52] 
[01:03:52] 
[01:03:52] 
[01:03:52] 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

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)

We no longer get two disjoint uses. =)

pietroalbini · 2018-05-14T10:33:34Z

Ping from triage @pnkfelix! This PR needs your review.

pnkfelix · 2018-05-14T13:00:04Z

i'll admit I was waiting for the perf run, but I'll take a look

Mark-Simulacrum · 2018-05-15T01:32:51Z

https://perf.rust-lang.org/compare.html?start=e5f80f2a4f016bf724a1cfb580619d71c8fd39ec&end=121e57e8284c60e07d3c886f6e5b8edf84b968c2&stat=instructions%3Au

pnkfelix · 2018-05-17T10:33:00Z

src/librustc_mir/borrow_check/nll/region_infer/mod.rs

@@ -1095,7 +1097,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {

    /// Tries to finds a good span to blame for the fact that `fr1`


might be nice to also fix the comment here to reflect the more general behavior

pnkfelix · 2018-05-17T10:35:20Z

src/librustc_mir/borrow_check/nll/region_infer/mod.rs

@@ -1112,7 +1097,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
        let relevant_constraint = self.constraints
            .iter_enumerated()
            .filter_map(|(i, constraint)| {
-                if self.liveness_constraints.contains(constraint.sub, elem) {
+                if !self.liveness_constraints.contains(constraint.sub, elem) {


(it would be nice if this one-line bugfix were attached to the commit that generalized blame_constraint)

pnkfelix · 2018-05-17T10:36:57Z

This seems fine to me. I had very small nits.

I don't want to r+ because I suspect @nikomatsakis may want to rebase it a little first? But if he's happy with the commit series the way it is, then go ahead and r=me it.

nikomatsakis · 2018-05-17T18:32:19Z

@bors r+

bors · 2018-05-17T18:32:20Z

📌 Commit a64ef13 has been approved by nikomatsakis

nikomatsakis · 2018-05-17T18:39:55Z

Normally I would clean up but I'm too busy today

Mark-Simulacrum · 2018-05-17T19:51:41Z

@bors p=10

bors · 2018-05-17T21:36:50Z

⌛ Testing commit a64ef13 with merge 612ca14...

@pnkfelix

stop considering location when computing outlives relationships This doesn't (yet?) use SEME regions, but it does ignore the location for outlives constraints. This makes (I believe) NLL significantly faster -- but we should do some benchmarks. It regresses the "get-default" family of use cases for NLL, which is a shame, but keeps the other benefits, and thus represents a decent step forward. r? @pnkfelix

bors · 2018-05-18T00:09:33Z

☀️ Test successful - status-appveyor, status-travis
Approved by: nikomatsakis
Pushing 612ca14 to master...

nikomatsakis added 5 commits May 9, 2018 23:21

generalize blame_span

1fb17ab

rename add to add_element

accfdcc

use chunks api for SparseBitMatrix and add a subset fn

964e069

ignore the point where the outlives requirement was added

434d59a

rust-highfive assigned pnkfelix May 10, 2018

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label May 10, 2018

rustfmt to pacify the mercilous tidy

c990309

WIP patch test stderr

72c235d

fix nll reference harder

6189602

kill get-default run-pass test

7ec8e51

It no longer passes, and the ui test subsumes it anyhow.

"fix" test region-liveness-two-disjoint-uses

a64ef13

We no longer get two disjoint uses. =)

nikomatsakis mentioned this pull request May 15, 2018

location-insensitive first pass rust-lang/polonius#29

Closed

pnkfelix reviewed May 17, 2018

View reviewed changes

pnkfelix added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels May 17, 2018

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels May 17, 2018

bors merged commit a64ef13 into rust-lang:master May 18, 2018

matthewjasper mentioned this pull request Jun 13, 2018

NLL no longer figures out non-lexical lifetimes within loop #51526

Open

pnkfelix mentioned this pull request Jul 31, 2018

non-lexical lifetimes (NLL) tracking issue #43234

Closed

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stop considering location when computing outlives relationships #50593

stop considering location when computing outlives relationships #50593

nikomatsakis commented May 10, 2018

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bors commented May 10, 2018

rust-highfive commented May 10, 2018

bors commented May 10, 2018

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pnkfelix May 17, 2018

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pnkfelix commented May 17, 2018

nikomatsakis commented May 17, 2018

bors commented May 17, 2018

nikomatsakis commented May 17, 2018

Mark-Simulacrum commented May 17, 2018

bors commented May 17, 2018

bors commented May 18, 2018

		@@ -1095,7 +1097,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {

		/// Tries to finds a good span to blame for the fact that `fr1`

stop considering location when computing outlives relationships #50593

stop considering location when computing outlives relationships #50593

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nikomatsakis commented May 10, 2018

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