[WIP] The Genesis of Generic Germination

[varkor]

Long had its coming been foretold: a collaborative effort with @yodaldevoid, set in motion by @jplatte, to beget a new Kind: one of a very different Sort to those that come before it. Amidst promises of ineffable powers previously thought unobtainable, few dared believe that the prophecies were true. But as they gazed upon that which claimed to be the Beginning, a few gentle sparks of hope fluttered deep within. It was not Time yet. But it was a Sign. And maybe, for some, that was enough.

There's a long way to go, but we're at the point where we would benefit from GitHub's reviewing capabilities.

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.

[00:04:28] travis_fold:start:tidy
travis_time:start:tidy
tidy check
[00:04:28] tidy error: /checkout/src/librustc_resolve/lib.rs:138: line longer than 100 chars
[00:04:28] tidy error: /checkout/src/librustdoc/core.rs:225: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustdoc/html/render.rs:1470: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustdoc/clean/mod.rs:1258: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustdoc/clean/mod.rs:2547: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustdoc/clean/mod.rs:2798: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustdoc/clean/mod.rs:3759: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/libsyntax/parse/parser.rs:5047: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/libsyntax/parse/parser.rs:5187: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc/ty/context.rs:2279: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc/ty/sty.rs:117: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc/ty/subst.rs:508: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc/ty/relate.rs:481: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc/ty/relate.rs:614: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc/ty/relate.rs:620: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc/infer/mod.rs:592: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc/infer/mod.rs:917: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc_typeck/check/mod.rs:5190: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc_typeck/diagnostics.rs:1043: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc_typeck/diagnostics.rs:1071: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc_typeck/astconv.rs:1534: TODO is deprecated; use FIXME
[00:04:28] tidy error: /checkout/src/librustc_typeck/collect.rs:1191: TODO is deprecated; use FIXME
[00:04:28] tidy error: duplicate error code: 85
[00:04:28] tidy error: /checkout/src/librustc_typeck/diagnostics.rs:1045: E0085: r##"
[00:04:28] tidy error: /checkout/src/librustc_typeck/diagnostics.rs:4798: //  E0085,
[00:04:28] tidy error: duplicate error code: 107
[00:04:28] tidy error: /checkout/src/librustc_typeck/diagnostics.rs:1043: // TODO(const_generics:docs): these should be unified with E0107 (i.e. these can just be
[00:04:28] tidy error: /checkout/src/librustc_typeck/diagnostics.rs:1291: E0107: r##"
[00:04:28] tidy error: duplicate error code: 86
[00:04:28] tidy error: /checkout/src/librustc_typeck/diagnostics.rs:1060: E0086: r##"
[00:04:28] tidy error: /checkout/src/librustc_typeck/diagnostics.rs:4799: //  E0086,
[00:04:29] Expected a gate test for the feature 'const_generics'.
[00:04:29] Hint: create a failing test file named 'feature-gate-const_generics.rs'
[00:04:29] tidy error: Found 1 features without a gate test.
[00:04:29]       in the 'ui' test suite, with its failures due to
[00:04:29]       missing usage of #![feature(const_generics)].
[00:04:29] Hint: If you already have such a test and don't want to rename it,
[00:04:29]       you can also add a // gate-test-const_generics line to the test file.
[00:04:29] some tidy checks failed
[00:04:29] 
[00:04:29] 
[00:04:29] 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"
[00:04:29] 
[00:04:29] 
[00:04:29] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test src/tools/tidy
[00:04:29] Build completed unsuccessfully in 0:00:50
[00:04:29] Build completed unsuccessfully in 0:00:50
[00:04:29] make: *** [tidy] Error 1
[00:04:29] Makefile:79: recipe for target 'tidy' failed

The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:0d7ce8e7
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
---
travis_time:end:213c91e3:start=1535050856368938027,finish=1535050856377184018,duration=8245991
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travis_time:start:0abcf093
$ 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
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travis_time:start:0080c712
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$ 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
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$ 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)

[bors]

☔️ The latest upstream changes (presumably #53662) made this pull request unmergeable. Please resolve the merge conflicts.

[kennytm]

(Somehow I read the title as "Genesis of Germanic Germination" and thought why we're adding i18n into rustc itself 😐)

[petrochenkov]

If S<MY_CONST> is supposed to work, then it can use same approach as identifiers in patterns.
In AST it's PatKind::Ident, but in HIR it's turned into a proper pattern based on resolution, for const arguments it would be something like ast::GenericArg::Ident.
I agree this is not necessary to do in this PR though.

[varkor]

(Note for triage: I'm going to get around to addressing these comments and hopefully fixing the existing crashes soon.)

[TimNN]

Ping from triage! Since it's been I while, I was wondering if you could give us a small update on the status of this PR?

[varkor]

I'm going to start investigating the ICE again soon (been busier than I expected). I think @eddyb's going to be leaving some comments soon as well.

[TimNN]

Ping from triage! Since it's been I while, I was wondering if you could give us a small update on the status of this PR?

[varkor]

I've made progress in my local branch since last time, though not quite ready to push. I think a full review will be unlikely before the 2018 edition though, as things are getting busy close to the deadline.

[TimNN]

@vakor: Thanks for the update!

[yodaldevoid]

It looks like this doesn't need to be implemented for ReverseMapper. fold_ty is only implemented because of some funkiness around closures and otherwise is just the default impl.

[mark-i-m]

#58583 merged 🎉

[varkor]

#59008 has been opened with the changes to type inference.

[varkor]

#59008 is blocked on some refactoring to consts for now, so #59170 has been opened in the meantime extending the support for const generics in rustdoc.

[Dylan-DPC]

ping from triage @varkor i'm assuming this is still blocked on #59170 ?

[varkor]

This is currently blocked on #59008 (#59170 was merged), which in turn is currently blocked on rust-lang-nursery/ena#22 (but which is expected to be merged soon).