Get a list of default filename extensions: File types
Get reference information about the Filename Extensions dialog box, see below the line.
The Filename Extensions dialog box is available from the Tools menu.
Use this dialog box to customize the filename extensions recognized by the build tools. This is useful if you have many source files with different filename extensions.
Toolchain
Lists the toolchains for which you have an IAR Embedded Workbench installed on your host computer. Select the toolchain you want to customize filename extensions for.
Note the * character indicates user-defined overrides. If there is no * character, factory settings are used.