build 938 syntax analysis and error highlighting is very slow

I have a ~1400 line Scala file which defines a class and an object. The class extends 5 traits. It uses mostly Java types. After making non-trivial changes, it takes nearly a minute for syntax analysis, inspections and error highlighting to finish, using 100% of one CPU core on a Core 2 Duo.

It's been a while since I've edited this file but I don't recall it being this slow in previous builds of the plugin.


Could you take a CPU snapshot during the slow highlighting?

CTRL-SHIFT-A Capture CPU Usage Data


That action isn't available. I don't have YourKit installed. Do I have to install the eval version?



Which IDEA version are you using?
EAP builds typically have the profiling agent enabled by default.

For production builds, see



I'm using EAP build IC-107.18 on Windows 7 Enterprse 64-bit.


Looks like the Community edition doesn't include YourKit profiler, so I must install the eval version.


It appears that the by-name parameter annotator is the main culprit. I had in fact just turned this option on this morning to see how useful it was. If I turn the option off, syntax analaysis and inspections complete in a few seconds.


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