On Fri, 29 Aug 2014 02:56:01 +0200 Gabor Greif wrote:

Devs,

I have built an UNREGISTERISED GHC, and the C-compiler used behind the scenes is clang. Now I get literally millions of warnings of the below kind:

+/var/folders/k9/fj_1d5h17m7c4gbyp2srqrhm0000gq/T/ghc11601_0/ghc11601_4.hc:688:1: + warning: attribute declaration must precede definition [-Wignored-attributes] +II_(s4Vv_closure); +^ + +/Users/ggreif/ghc-head/includes/Stg.h:213:63: + note: expanded from macro 'II_' +#define II_(X) static StgWordArray (X) GNU_ATTRIBUTE(aligned (8)) + ^ + +/Users/ggreif/ghc-head/includes/Stg.h:175:42: + note: expanded from macro 'GNU_ATTRIBUTE' +#define GNU_ATTRIBUTE(at) __attribute__((at)) + ^ + +/var/folders/k9/fj_1d5h17m7c4gbyp2srqrhm0000gq/T/ghc11601_0/ghc11601_4.hc:588:16: + note: previous definition is here +static StgWord s4Vv_closure[] = { + ^

It seems like the "II_" and "EI_" prototypes *follow* the real thing, and because clang is more picky with attribute placement, we get all those warnings.

They just occur many times in the source, thus not only before but also after definition.

compiler/cmm/PprC.hs:pprExternDecl is the function that puts together the "II_(...)" and "EI_(...)", but where does the "static StgWord s4Vv_closure[] = {" come from?

pprWordArray :: CLabel -> [CmmStatic] -> SDoc

I just want to flip the order of their occurrence.

I think it would be a good thing to split .hc file lifting all external and local declarations up (and print only unique ones). It should shrink .hc file size a bit and make it nicer to read. -- Sergei