Remove unused toolbar itemsEclipse Mars installed as a part SW4STM32 uses two rows of toolbar items and most of them are probably not frequently used. To get rid of them use Window/Perspective/Customize perspective... menu.
Remove status barStatus bar does not seem to present any useful information. Line numbers are displayed in editor window anyway, current column number and Insert/Overwrite mode state don't not seem important to me. To hide status bar open e4_basestyle.css file from Eclipse directory (in my case: Ac6\SystemWorkbench\plugins\org.eclipse.ui.themes_1.1.1.v20151026-1355\css) and add at the bottom of it:
Update file timestamp before buildingProject properties, C/C++ build, Settings, Build Steps, Pre-build steps:
For a list of environment variables look at C/C++ Build, Build Variables and check "Show system variables":