From: bors <bors@rust-lang.org>
Date: Sat, 8 Apr 2017 14:05:06 +0000 (+0000)
Subject: Auto merge of #41055 - Archytaus:compile-fail/const-match-pattern-arm, r=arielb1
X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;h=a61011761deeab9e308e6d103b1dc7aaf334f6e3;p=rust.git

Auto merge of #41055 - Archytaus:compile-fail/const-match-pattern-arm, r=arielb1

Fixed ICEs with pattern matching in const expression

Fixed 2 ICEs with when pattern matching inside a constant expression.

Both of these ICEs now resolve to an appropriate compiler error.

1. ICE was caused by a compiler bug to implement discriminant const qualify.

    I removed this intentionally thrown bug and changed it to a FIXME as the unimplemented expression type is handled as a compiler error elsewhere.

2. ICE was caused during a drop check when checking if a variable lifetime outlives the current scope if there was no parent scope .

    I've changed it to stop checking if there is no parent scope for the current scope. It is valid syntax for a const variable to be assigned a match expression with no enclosing scope.

    The ICE seemed to mainly be used as a defensive check for bugs elsewhere.

Fixes #38199.
Fixes #31577.
Fixes #29093.
Fixes #40012.
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a61011761deeab9e308e6d103b1dc7aaf334f6e3