I'm not following this thread, but is it worth a ticket? Or better user manual documentation? Or something?
Simon | -----Original Message----- | From: ghc-devs [mailto:ghc-devs-boun...@haskell.org] On Behalf Of Simon | Marlow | Sent: 20 June 2014 21:25 | To: Yuras Shumovich; ghc-devs@haskell.org | Subject: Re: CmmLint error when doing safe ccall from cmm | | On 20/06/14 15:03, Yuras Shumovich wrote: | > Hello, | > | > I'm trying to do safe ccall from cmm (see below for the code). It | > seems to work, but -dcmm-lint is not satisfied: | > | > /opt/ghc-7.8.2/bin/ghc --make -o test hs.hs cmm.cmm c.c -dcmm-lint | > -fforce-recomp Cmm lint error: | > in basic block c4 | > in assignment: | > _c1::I32 = R1; | > Reg ty: I32 | > Rhs ty: I64 | > Program was: | > {offset | > c5: _c0::I64 = R1; | > _c2::I64 = c_test; | > _c3::I32 = %MO_UU_Conv_W64_W32(_c0::I64); | > I64[(young<c4> + 8)] = c4; | > foreign call "ccall" arg hints: [] result hints: [] | (_c2::I64)(...) returns to c4 args: ([_c3::I32]) ress: | ([_c1::I32])ret_args: 8ret_off: 8; | > c4: _c1::I32 = R1; | > R1 = %MO_SS_Conv_W32_W64(_c1::I32); | > call (P64[(old + 8)])(R1) args: 8, res: 0, upd: 8; | > } | > | > <no location info>: | > Compilation had errors | | I believe we only support 64-bit results on a 64-bit platform, but we | you can always narrow to 32 bits with an MO_Conv afterwards if you want. | This is essentially what happens when you call a function that returns | CInt using the FFI - you can always try that and see what Cmm you get. | | Also, I'll be mildly surprised if using safe foreign calls from hand- | written Cmm works, since I don't believe we use them anywhere so it | isn't likely to be well tested :-) | | Cheers, | Simon | | | > The same code without "safe" annotation passes cmm lint. Is it my | > error or ghc bug? How can I do safe ccall in cmm correctly? | > | > Here is the code: | > | > == c.c == | > #include <assert.h> | > | > int c_test(int i) | > { | > assert(i == 1); | > return 2; | > } | > | > == cmm.cmm | > #include "Cmm.h" | > | > cmm_test(W_ i) | > { | > CInt i1; | > (i1) = ccall c_test(W_TO_INT(i)) "safe"; | > return (TO_W_(i1)); | > } | > | > == hs.hs == | > {-# LANGUAGE GHCForeignImportPrim #-} | > {-# LANGUAGE ForeignFunctionInterface #-} {-# LANGUAGE MagicHash #-} | > {-# LANGUAGE UnboxedTuples #-} {-# LANGUAGE UnliftedFFITypes #-} | > | > import GHC.Prim | > import GHC.Types | > import Control.Exception | > | > foreign import prim "cmm_test" test :: Int# -> Int# | > | > main :: IO () | > main = do | > let i1 = test 1# | > assert (I# i1 == 2) (return ()) | > | > | > Thanks, | > Yuras | > | > | > _______________________________________________ | > ghc-devs mailing list | > ghc-devs@haskell.org | > http://www.haskell.org/mailman/listinfo/ghc-devs | > | | _______________________________________________ | ghc-devs mailing list | ghc-devs@haskell.org | http://www.haskell.org/mailman/listinfo/ghc-devs _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://www.haskell.org/mailman/listinfo/ghc-devs
