proc_macro: Stay on the "use the cache" path more #50069
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Discovered in rust-lang#50061 we're falling off the "happy path" of using a stringified token stream more often than we should. This was due to the fact that a user-written token like `0xf` is equality-different from the stringified token of `15` (despite being semantically equivalent). This patch updates the call to `eq_unspanned` with an even more awful solution, `probably_equal_for_proc_macro`, which ignores the value of each token and basically only compares the structure of the token stream, assuming that the AST doesn't change just one token at a time. While this is a step towards fixing rust-lang#50061 there is still one regression from rust-lang#49154 which needs to be fixed.
|
r? @nrc |
pietroalbini
added
the
S-waiting-on-review
|
Oh my. @bors: r+ (but I hope you feel bad about this :-) ) |
|
📌 Commit e934873 has been approved by |
bors
added
S-waiting-on-bors
|
I do feel bad :( This is indeed casting a shadow of a doubt on macros 1.2... |
bors
added a commit
that referenced
this pull request
Apr 20, 2018
proc_macro: Stay on the "use the cache" path more Discovered in #50061 we're falling off the "happy path" of using a stringified token stream more often than we should. This was due to the fact that a user-written token like `0xf` is equality-different from the stringified token of `15` (despite being semantically equivalent). This patch updates the call to `eq_unspanned` with an even more awful solution, `probably_equal_for_proc_macro`, which ignores the value of each token and basically only compares the structure of the token stream, assuming that the AST doesn't change just one token at a time. While this is a step towards fixing #50061 there is still one regression from #49154 which needs to be fixed.
|
☀️ Test successful - status-appveyor, status-travis |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Discovered in #50061 we're falling off the "happy path" of using a stringified
token stream more often than we should. This was due to the fact that a
user-written token like
0xfis equality-different from the stringified tokenof
15(despite being semantically equivalent).This patch updates the call to
eq_unspannedwith an even more awful solution,probably_equal_for_proc_macro, which ignores the value of each token andbasically only compares the structure of the token stream, assuming that the AST
doesn't change just one token at a time.
While this is a step towards fixing #50061 there is still one regression
from #49154 which needs to be fixed.