I did some test with non-used units. There is no clear exe size difference by my testing. But I can't find any information in the document. My question is, will non-used unit uses increase the output file size?

CodePudding user response：

When you add some unused units into “uses part” of your code it’s not good practice, but it’s increase size of final exe-file by itself. Compiler analyze whole code and cutoff all unused parts, so it’s increase compilation time. But you need to remember one tricky things – non-uses units can contain code-parts that can be used not in a direct way. It can be “initialization part” of unit or some “Class constructors” that can be triggered automatically, so compiler will include it(and all chain of used types/units) into your exe-file. One more thing – when you compile some bpl-file – compiler optimization does not work in the same way, because it can not know what you will use from this bpl in future projects which will use this bpl.