It should tell Dev that you wish to recompile a source file in case one of the header files it includes is newer than the object file (obtained by compiling the source file).
I don't know how things are in latest version of Dev, but on 4.9.6.0 (or better: up to 4.9.6.0), the feature was not working as advertised.
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At Tools / Compiler Options / Code Generation / Make File Generation.
"Use fast but imperfect dependency generator"
I really dont understand what this option does.
It should tell Dev that you wish to recompile a source file in case one of the header files it includes is newer than the object file (obtained by compiling the source file).
I don't know how things are in latest version of Dev, but on 4.9.6.0 (or better: up to 4.9.6.0), the feature was not working as advertised.