----------------------------------------------------------------------------- -- -- Stg to C-- code generation -- -- (c) The University of Glasgow 2004-2006 -- ----------------------------------------------------------------------------- module StgCmm ( codeGen ) where #define FAST_STRING_NOT_NEEDED #include "HsVersions.h" import StgCmmProf import StgCmmMonad import StgCmmEnv import StgCmmBind import StgCmmCon import StgCmmLayout import StgCmmHeap import StgCmmUtils import StgCmmClosure import StgCmmHpc import StgCmmTicky import MkZipCfgCmm import Cmm import CmmUtils import CLabel import PprCmm import StgSyn import PrelNames import DynFlags import StaticFlags import HscTypes import CostCentre import Id import IdInfo import Type import DataCon import Name import TyCon import Module import ErrUtils import Outputable codeGen :: DynFlags -> Module -> [TyCon] -> [Module] -- Directly-imported modules -> CollectedCCs -- (Local/global) cost-centres needing declaring/registering. -> [(StgBinding,[(Id,[Id])])] -- Bindings to convert, with SRTs -> HpcInfo -> IO [CmmZ] -- Output codeGen dflags this_mod data_tycons imported_mods cost_centre_info stg_binds hpc_info = do { showPass dflags "New CodeGen" ; let way = buildTag dflags main_mod = mainModIs dflags -- Why? -- ; mapM_ (\x -> seq x (return ())) data_tycons ; code_stuff <- initC dflags this_mod $ do { cmm_binds <- mapM (getCmm . cgTopBinding dflags) stg_binds ; cmm_tycons <- mapM cgTyCon data_tycons ; cmm_init <- getCmm (mkModuleInit way cost_centre_info this_mod main_mod imported_mods hpc_info) ; return (cmm_binds ++ concat cmm_tycons ++ [cmm_init]) } -- Put datatype_stuff after code_stuff, because the -- datatype closure table (for enumeration types) to -- (say) PrelBase_True_closure, which is defined in -- code_stuff -- N.B. returning '[Cmm]' and not 'Cmm' here makes it -- possible for object splitting to split up the -- pieces later. ; dumpIfSet_dyn dflags Opt_D_dump_cmmz "New Cmm" (pprCmms code_stuff) ; return code_stuff } --------------------------------------------------------------- -- Top-level bindings --------------------------------------------------------------- {- 'cgTopBinding' is only used for top-level bindings, since they need to be allocated statically (not in the heap) and need to be labelled. No unboxed bindings can happen at top level. In the code below, the static bindings are accumulated in the @MkCgState@, and transferred into the ``statics'' slot by @forkStatics@. This is so that we can write the top level processing in a compositional style, with the increasing static environment being plumbed as a state variable. -} cgTopBinding :: DynFlags -> (StgBinding,[(Id,[Id])]) -> FCode () cgTopBinding dflags (StgNonRec id rhs, _srts) = do { id' <- maybeExternaliseId dflags id ; info <- cgTopRhs id' rhs ; addBindC (cg_id info) info -- Add the *un-externalised* Id to the envt, -- so we find it when we look up occurrences } cgTopBinding dflags (StgRec pairs, _srts) = do { let (bndrs, rhss) = unzip pairs ; bndrs' <- mapFCs (maybeExternaliseId dflags) bndrs ; let pairs' = zip bndrs' rhss ; fixC_(\ new_binds -> do { addBindsC new_binds ; mapFCs ( \ (b,e) -> cgTopRhs b e ) pairs' }) ; return () } -- Urgh! I tried moving the forkStatics call from the rhss of cgTopRhs -- to enclose the listFCs in cgTopBinding, but that tickled the -- statics "error" call in initC. I DON'T UNDERSTAND WHY! cgTopRhs :: Id -> StgRhs -> FCode CgIdInfo -- The Id is passed along for setting up a binding... -- It's already been externalised if necessary cgTopRhs bndr (StgRhsCon _cc con args) = forkStatics (cgTopRhsCon bndr con args) cgTopRhs bndr (StgRhsClosure cc bi fvs upd_flag srt args body) = ASSERT(null fvs) -- There should be no free variables setSRTLabel (mkSRTLabel (idName bndr) (idCafInfo bndr)) $ forkStatics (cgTopRhsClosure bndr cc bi upd_flag srt args body) --------------------------------------------------------------- -- Module initialisation code --------------------------------------------------------------- {- The module initialisation code looks like this, roughly: FN(__stginit_Foo) { JMP_(__stginit_Foo_1_p) } FN(__stginit_Foo_1_p) { ... } We have one version of the init code with a module version and the 'way' attached to it. The version number helps to catch cases where modules are not compiled in dependency order before being linked: if a module has been compiled since any modules which depend on it, then the latter modules will refer to a different version in their init blocks and a link error will ensue. The 'way' suffix helps to catch cases where modules compiled in different ways are linked together (eg. profiled and non-profiled). We provide a plain, unadorned, version of the module init code which just jumps to the version with the label and way attached. The reason for this is that when using foreign exports, the caller of startupHaskell() must supply the name of the init function for the "top" module in the program, and we don't want to require that this name has the version and way info appended to it. We initialise the module tree by keeping a work-stack, * pointed to by Sp * that grows downward * Sp points to the last occupied slot -} mkModuleInit :: String -- the "way" -> CollectedCCs -- cost centre info -> Module -> Module -- name of the Main module -> [Module] -> HpcInfo -> FCode () mkModuleInit way cost_centre_info this_mod main_mod imported_mods hpc_info = do { -- Allocate the static boolean that records if this -- module has been registered already emitData Data [CmmDataLabel moduleRegdLabel, CmmStaticLit zeroCLit] ; init_hpc <- initHpc this_mod hpc_info ; init_prof <- initCostCentres cost_centre_info -- We emit a recursive descent module search for all modules -- and *choose* to chase it in :Main, below. -- In this way, Hpc enabled modules can interact seamlessly with -- not Hpc enabled moduled, provided Main is compiled with Hpc. ; updfr_sz <- getUpdFrameOff ; tail <- getCode (pushUpdateFrame imports (do updfr_sz' <- getUpdFrameOff emit $ mkReturn (ret_e updfr_sz') [] (pop_ret_loc updfr_sz'))) ; emitSimpleProc real_init_lbl $ (withFreshLabel "ret_block" $ \retId -> catAGraphs [ check_already_done retId updfr_sz , init_prof , init_hpc , tail]) -- Make the "plain" procedure jump to the "real" init procedure ; emitSimpleProc plain_init_lbl (jump_to_init updfr_sz) -- When compiling the module in which the 'main' function lives, -- (that is, this_mod == main_mod) -- we inject an extra stg_init procedure for stg_init_ZCMain, for the -- RTS to invoke. We must consult the -main-is flag in case the -- user specified a different function to Main.main -- Notice that the recursive descent is optional, depending on what options -- are enabled. ; whenC (this_mod == main_mod) (emitSimpleProc plain_main_init_lbl (rec_descent_init updfr_sz)) } where plain_init_lbl = mkPlainModuleInitLabel this_mod real_init_lbl = mkModuleInitLabel this_mod way plain_main_init_lbl = mkPlainModuleInitLabel rOOT_MAIN jump_to_init updfr_sz = mkJump (mkLblExpr real_init_lbl) [] updfr_sz -- Main refers to GHC.TopHandler.runIO, so make sure we call the -- init function for GHC.TopHandler. extra_imported_mods | this_mod == main_mod = [gHC_TOP_HANDLER] | otherwise = [] all_imported_mods = imported_mods ++ extra_imported_mods imports = map (\mod -> mkLblExpr (mkModuleInitLabel mod way)) (filter (gHC_PRIM /=) all_imported_mods) mod_reg_val = CmmLoad (mkLblExpr moduleRegdLabel) bWord check_already_done retId updfr_sz = mkCmmIfThenElse (cmmNeWord (CmmLit zeroCLit) mod_reg_val) (mkLabel retId <*> mkReturn (ret_e updfr_sz) [] (pop_ret_loc updfr_sz)) mkNop <*> -- Set mod_reg to 1 to record that we've been here mkStore (mkLblExpr moduleRegdLabel) (CmmLit (mkIntCLit 1)) -- The return-code pops the work stack by -- incrementing Sp, and then jumps to the popped item ret_e updfr_sz = CmmLoad (CmmStackSlot (CallArea Old) updfr_sz) gcWord ret_code updfr_sz = mkJump (ret_e updfr_sz) [] (pop_ret_loc updfr_sz) -- mkAssign spReg (cmmRegOffW spReg 1) <*> -- mkJump (CmmLoad (cmmRegOffW spReg (-1)) bWord) [] updfr_sz pop_ret_loc updfr_sz = updfr_sz - widthInBytes (typeWidth bWord) rec_descent_init updfr_sz = if opt_SccProfilingOn || isHpcUsed hpc_info then jump_to_init updfr_sz else ret_code updfr_sz --------------------------------------------------------------- -- Generating static stuff for algebraic data types --------------------------------------------------------------- {- [These comments are rather out of date] Macro Kind of constructor CONST_INFO_TABLE@ Zero arity (no info -- compiler uses static closure) CHARLIKE_INFO_TABLE Charlike (no info -- compiler indexes fixed array) INTLIKE_INFO_TABLE Intlike; the one macro generates both info tbls SPEC_INFO_TABLE SPECish, and bigger than or equal to MIN_UPD_SIZE GEN_INFO_TABLE GENish (hence bigger than or equal to MIN_UPD_SIZE@) Possible info tables for constructor con: * _con_info: Used for dynamically let(rec)-bound occurrences of the constructor, and for updates. For constructors which are int-like, char-like or nullary, when GC occurs, the closure tries to get rid of itself. * _static_info: Static occurrences of the constructor macro: STATIC_INFO_TABLE. For zero-arity constructors, \tr{con}, we NO LONGER generate a static closure; it's place is taken by the top level defn of the constructor. For charlike and intlike closures there is a fixed array of static closures predeclared. -} cgTyCon :: TyCon -> FCode [CmmZ] -- All constructors merged together cgTyCon tycon = do { constrs <- mapM (getCmm . cgDataCon) (tyConDataCons tycon) -- Generate a table of static closures for an enumeration type -- Put the table after the data constructor decls, because the -- datatype closure table (for enumeration types) -- to (say) PrelBase_$wTrue_closure, which is defined in code_stuff -- Note that the closure pointers are tagged. -- N.B. comment says to put table after constructor decls, but -- code puts it before --- NR 16 Aug 2007 ; extra <- cgEnumerationTyCon tycon ; return (extra ++ constrs) } cgEnumerationTyCon :: TyCon -> FCode [CmmZ] cgEnumerationTyCon tycon | isEnumerationTyCon tycon = do { tbl <- getCmm $ emitRODataLits (mkLocalClosureTableLabel (tyConName tycon) NoCafRefs) [ CmmLabelOff (mkLocalClosureLabel (dataConName con) NoCafRefs) (tagForCon con) | con <- tyConDataCons tycon] ; return [tbl] } | otherwise = return [] cgDataCon :: DataCon -> FCode () -- Generate the entry code, info tables, and (for niladic constructor) -- the static closure, for a constructor. cgDataCon data_con = do { let -- To allow the debuggers, interpreters, etc to cope with -- static data structures (ie those built at compile -- time), we take care that info-table contains the -- information we need. (static_cl_info, _) = layOutStaticConstr data_con arg_reps (dyn_cl_info, arg_things) = layOutDynConstr data_con arg_reps emit_info cl_info ticky_code = emitClosureAndInfoTable cl_info NativeDirectCall [] $ mk_code ticky_code mk_code ticky_code = -- NB: We don't set CC when entering data (WDP 94/06) do { _ <- ticky_code ; ldvEnter (CmmReg nodeReg) ; tickyReturnOldCon (length arg_things) ; emitReturn [cmmOffsetB (CmmReg nodeReg) (tagForCon data_con)] } -- The case continuation code expects a tagged pointer arg_reps :: [(PrimRep, Type)] arg_reps = [(typePrimRep ty, ty) | ty <- dataConRepArgTys data_con] -- Dynamic closure code for non-nullary constructors only ; whenC (not (isNullaryRepDataCon data_con)) (emit_info dyn_cl_info tickyEnterDynCon) -- Dynamic-Closure first, to reduce forward references ; emit_info static_cl_info tickyEnterStaticCon } --------------------------------------------------------------- -- Stuff to support splitting --------------------------------------------------------------- -- If we're splitting the object, we need to externalise all the -- top-level names (and then make sure we only use the externalised -- one in any C label we use which refers to this name). maybeExternaliseId :: DynFlags -> Id -> FCode Id maybeExternaliseId dflags id | dopt Opt_SplitObjs dflags, -- Externalise the name for -split-objs isInternalName name = do { mod <- getModuleName ; returnFC (setIdName id (externalise mod)) } | otherwise = returnFC id where externalise mod = mkExternalName uniq mod new_occ loc name = idName id uniq = nameUnique name new_occ = mkLocalOcc uniq (nameOccName name) loc = nameSrcSpan name -- We want to conjure up a name that can't clash with any -- existing name. So we generate -- Mod_$L243foo -- where 243 is the unique.