From: bors <bors@rust-lang.org>
Date: Sun, 9 Aug 2020 18:19:34 +0000 (+0000)
Subject: Auto merge of #75137 - Aaron1011:fix/hygiene-skip-expndata, r=petrochenkov
X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;h=39e593ab14c53fda63c3f2756716c5ad3cbb6465;p=rust.git

Auto merge of #75137 - Aaron1011:fix/hygiene-skip-expndata, r=petrochenkov

Don't serialize ExpnData for foreign crates

When we encode an ExpnId into the crate metadata, we write out the
CrateNum of the crate that 'owns' the corresponding `ExpnData`, which
is later used to decode the `ExpnData` from its owning crate.

However, we current serialize the `ExpnData` for all `ExpnIds` that we
serialize, even if the `ExpnData` was already serialized into a foreign
crate. This commit skips encoding this kind of `ExpnData`, which should
hopefully speed up metadata encoding and reduce the total metadata size.
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39e593ab14c53fda63c3f2756716c5ad3cbb6465