CLion 2017.2 Help

Tuning CLion

In this part:

Changing CLion properties

CLion makes it possible to change the *.vmoptions and the idea.properties files without editing them in the CLion installation folder.

To create an empty idea.properties file or to copy the *.vmoptions file, choose Help | Edit Custom Properties... or Help | Edit Custom VM Options... from the main menu respectively.

Managing the *.vmoptions file

The location of the *.vmoptions file depends on your operating system:

  • For Windows: <CLion installation folder>/bin/clion64.exe.vmoptions
  • For *NIX: <CLion installation folder>/bin/clion64.vmoptions
  • For macOS, you need to make a copy of the clion.vmoptions file in the IDE preferences folder and then edit this copy. The reason is that the app bundle is signed and you should not modify any files inside the bundle.

To avoid editing files in the CLion installation folder, do one of the following:

  • From the main menu, choose Help | Edit Custom VM Options to create a copy of the clion.vmoptions file in the user home directory.
  • Copy the existing file from the CLion installation folder somewhere and save the path to this location in the CL_VM_OPTIONS environment variable.
  • Copy the existing <CLion installation folder>/bin/clion.exe.vmoptions or the <CLion installation folder>/bin/clion64.exe.vmoptions file from the CLion installation folder into your user home directory.

Then edit this file in the new location.

If the CL_VM_OPTIONS environment variable is defined, or the *.vmoptions file exists, this file is used instead of the one located in the CLion installation folder.

Example: Increasing the heap size

To increase CLion heap size, you should copy the original clion.vmoptions file to the above-mentioned location, and then modify the -Xmx setting.

Managing the idea.properties file

The idea.properties file located in the bin directory of the CLion installation folder should not be edited. Instead of editing the original idea.properties file, create an idea.properties file in the following location, open it for editing and add the required properties:

  • For Windows: %\USERPROFILE%\\.clionXX\config
  • For *NIX: ~/.clionXX/config
  • For macOS: ~/Library/Preferences/clionXX/config

To open the idea.properties file in the editor, choose Help | Edit Custom Properties. If the file does not exist yet, CLion creates it and opens in the editor.

Example: Changing the case of unicode literals

CLion allows defining whether non-ascii characters should use literals like '\u00AB' or '\00ab'.

This behavior is controlled by the idea.native2ascii.lowercase system property. By default, upper-case characters are used.

If you wish to use lower-case characters, create the idea.properties file in the location specified above, open it for editing and add the following line:

idea.native2ascii.lowercase=true

Specifying custom JDK, properties, or vmoptions files across platforms

A custom JDK, as well as *.properties and *.vmoptions files are specified across platforms in a unified way.

All launchers look at the following environment variables:

  • $<IDE-NAME>_JDK (<IDE-NAME>_JDK_64)
  • $<IDE-NAME>_PROPERTIES
  • $<IDE-NAME>_VM_OPTIONS
Last modified: 29 November 2017

See Also