Compilation memory use

[Anonymouse]

TL;DR: Is there a way to tell what module or other section of a 
codebase is eating memory when compiling?

I'm keeping track of compilation memory use using zsh `time` with 
some environmental variables. It typically looks like this.

```
$ time dub build -c dev
Performing "debug" build using /usr/bin/dmd for x86_64.
[...]
Linking...
To force a rebuild of up-to-date targets, run again with --force.
dub build -c dev   9.47s  user 1.53s system 105% cpu 10.438 total
avg shared (code):         0 KB
avg unshared (data/stack): 0 KB
total (sum):               0 KB
max memory:                4533 MB
page faults from disk:     1
other page faults:         1237356
```

So it tells me the maximum memory that was required to compile it 
all. However, it only tells me just that; there's no way to know 
what part of the code is expensive and what part isn't.

I can copy dub's dmd command and run it with `-v` and try to 
infer that the modules that are slow to pass semantic3 are also 
the hungry ones. But are they?

Is there a better metric?