Fix performance regression in compiler around behaviours #2001
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When the commit at erlang@8c4a74a introduced a recursive search for build elements, it accidentally did so using a function that accepts a regex for its match. In doing so, if a behaviour or include had a name such as `common_prefix` and that multiple other modules used the name `common_prefix_<rest_of_name>`, all the other files would be seen as dependencies to be checked in a directed graph. This resulted in continuous re-checking of files that kept depending on each others and blew the compile time up exponentially. By using a delimitation on the regex (^<modulename>$), the build comes back down to finding only the right files and becomes fast again.
ferd
changed the title
tsloughter
approved these changes
Jan 23, 2019
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When the commit at 8c4a74a
introduced a recursive search for build elements, it accidentally did so
using a function that accepts a regex for its match.
In doing so, if a behaviour or include had a name such as
common_prefixand that multiple other modules used the namecommon_prefix_<rest_of_name>, all the other files would be seen asdependencies to be checked in a directed graph.
This resulted in continuous re-checking of files that kept depending on
each others and blew the compile time up exponentially.
By using a delimitation on the regex (
^<modulename>$), the build comesback down to finding only the right files and becomes fast again.
Fixes #1997