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JITProf Visualization

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This repository contains dynamic analyses for JavaScript code based on Jalangi2. It mainly consists of analyses ported from JITProf.

What is JITProf?

JITProf is a tool that tells you which part of your JavaScript code may be slow on JIT-engine. We call those slow code JIT-unfriendly code.

For more details, see this GitHub repository.

Academic Resources: Preprint in ESEC/FSE'15 | Presentation Slides | Technical Report | Bibtex

Why Visualization?

Existing JIT-unfriendly code detection tools simply dump a list of warnings. The warning messages contain the warning type, source location and some structured information that is specific to the type of problems detected (e.g., inconsistent hidden classes that cause inline cache miss etc.). Normally, to show the whole problem, a single warning can contain dozens or even hundreds of lines of text in the console. This makes debugging based on the warning message tedious and less productive. Visualizing warning generated by JITProf can hopefully make the debugging process more delightful and productive.

Visualization Demo


Make sure that your computer meets these requirements.

To run analyses with Jalangi2 on real-world websites, you need to install:

To install, type the following commands in your console:

git clone
cd jitprof-visualization
npm install


All the following commands should be executed under directory jalangi2analyses/.

Run JITProf in Browser

node src/js/command/run.js jitprof

This command sets a web proxy, open a web page with your browser (e.g., Chrome or Safari). Click the Jalangi button on your web page to view the analysis result.
To close the web proxy, simply rerun the above command (See Step-by-Step Guide).

Note: To run JITProf and DLint on node.js, see this Wiki page.


To configure which analysis module to be used, see this Wiki page.


DLint and JITProf is distributed under the Apache License.


Warning Visualization for JIT-unfriendly Code in JavaScript






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