问题
Usually, when ghc is compiling a source code, it will produce at least an .o (object) and a .hi (interface) file.
In the interest of diminishing compilation time, if I only need an interface file, can I somehow order ghc to abandon everything else and just give me said interface file? Or, otherwise, obtain that interface by any kind of lowly guile?
I found this ghc user guide part and it says nothing of such. This one doesn't even mention "interface" anywhere in its text. (In particular, -fno-code doesn't generate it.) It must mean there's no easy way. In this question from five years ago, nothing floated up, but by chance things are different now?
Most likely, I expect it to take a hack to ghc. If so, I'd like directions:
- Is it reasonable to submit a feature request to trac, or (likely) I should rather go for it myself?
- How is
.hifile distinct from something like-ddump-types, just binary? - Is there certainty that composing a
.hifile takes strictly less compilation stages than a complete.ofile? (For example, if there are hashes of machine code fragments within.hi, the corresponding code will probably have to be generated, which means nothing is to be gained here.)
Otherwise, perhaps I can just extract related parts from ghc code so that I can then compile a .hi file from the output of -ddump-types or the like?
回答1:
Actually, there is a flag -fno-code -fwrite-interface that does this. It actually cuts compilation time for even a simplistic example by about a quarter.
来源：https://stackoverflow.com/questions/48682283/is-there-a-way-to-only-compile-haskell-source-to-interface-file-not-further