Clearer error message when regex exceeds space limit #1428
Merged
+7
−2
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
zimbatm
approved these changes
Jun 30, 2017
edolstra
reviewed
Jun 30, 2017
src/libexpr/primops.cc
Outdated
| throw EvalError("invalid regular expression ‘%s’, at %s", re, pos); | ||
| } catch (std::regex_error &e) { | ||
| if (e.code() == std::regex_constants::error_space) { | ||
| throw EvalError("regular expression exceeds _GLIBCXX_REGEX_STATE_LIMIT ‘%s’, at %s", re, pos); |
There was a problem hiding this comment.
Just a nitpick: _GLIBCXX_REGEX_STATE_LIMIT is libstdc++ specific. Maybe something like "insufficient memory for regular expression ..."?
rimmington
force-pushed
the
clearer-regex-space-error
branch
from
f5fe993 to
6b5532d
Compare
|
@edolstra I've moved mention of the specific macro to a comment. I'm hesitant to use a phrase like "insufficient memory", because (at least in libstdc++) the limit isn't related to the amount of memory available to the process and so might lead people down the wrong path. The wording is still a bit awkward. |
rimmington
force-pushed
the
clearer-regex-space-error
branch
from
6b5532d to
17bb00d
Compare
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Outdated suggestions cannot be applied.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.
While investigating why nixpkgs-mozilla stopped working on our Hydra instance, I discovered that there's an upper limit to the size of a regular expression. This took quite a while, because Nix reported "invalid regular expression" when the limit was exceeded but the expression seemed syntactically valid.
This PR improves the error message in this specific case. I tried using
e.what()but the resulting message was very unhelpful (literallyregex_error).