Does dmd not always compile all of the source code?

[A Guy With a Question]

On Wednesday, 6 December 2017 at 19:19:09 UTC, A Guy With a 
Question wrote:
> It seems D's fast compile times are achieved by skipping 
> semantic checking and even parsing when it doesn't feel it's 
> needed. I strongly disagree with this decision. This could 
> leave complex dormant time bombs that break builds unexpectedly 
> and even accidentally. It's understandable in certain 
> situations where there is enough information, but the first 
> step to testing code, is first making sure it compiles...I 
> don't want the compiler making decisions on what is worthy to 
> compile. If I pass a d source file into it, I want to know if 
> it's valid. This is unfortunate. This might be a deal breaker 
> for me.

I'm very concerned of working with a language that, at minimum, 
doesn't let me know if a file I passed in even contains valid 
code.