diff options
Diffstat (limited to 'compiler/GHC/Unit/Home/ModInfo.hs')
| -rw-r--r-- | compiler/GHC/Unit/Home/ModInfo.hs | 75 |
1 files changed, 68 insertions, 7 deletions
diff --git a/compiler/GHC/Unit/Home/ModInfo.hs b/compiler/GHC/Unit/Home/ModInfo.hs index d66019a3ea..45129ddfb0 100644 --- a/compiler/GHC/Unit/Home/ModInfo.hs +++ b/compiler/GHC/Unit/Home/ModInfo.hs @@ -1,6 +1,13 @@ -- | Info about modules in the "home" unit module GHC.Unit.Home.ModInfo ( HomeModInfo (..) + , HomeModLinkable(..) + , homeModInfoObject + , homeModInfoByteCode + , emptyHomeModInfoLinkable + , justBytecode + , justObjects + , bytecodeAndObjects , HomePackageTable , emptyHomePackageTable , lookupHpt @@ -27,7 +34,7 @@ import GHC.Unit.Module.ModIface import GHC.Unit.Module.ModDetails import GHC.Unit.Module -import GHC.Linker.Types ( Linkable(..) ) +import GHC.Linker.Types ( Linkable(..), isObjectLinkable ) import GHC.Types.Unique import GHC.Types.Unique.DFM @@ -35,6 +42,7 @@ import GHC.Types.Unique.DFM import GHC.Utils.Outputable import Data.List (sortOn) import Data.Ord +import GHC.Utils.Panic -- | Information about modules in the package being compiled data HomeModInfo = HomeModInfo @@ -48,25 +56,78 @@ data HomeModInfo = HomeModInfo -- This field is LAZY because a ModDetails is constructed by knot tying. - , hm_linkable :: !(Maybe Linkable) + , hm_linkable :: !HomeModLinkable -- ^ The actual artifact we would like to link to access things in - -- this module. + -- this module. See Note [Home module build products] -- - -- 'hm_linkable' might be Nothing: + -- 'hm_linkable' might be empty: -- -- 1. If this is an .hs-boot module -- -- 2. Temporarily during compilation if we pruned away -- the old linkable because it was out of date. -- - -- After a complete compilation ('GHC.load'), all 'hm_linkable' fields - -- in the 'HomePackageTable' will be @Just@. - -- -- When re-linking a module ('GHC.Driver.Main.HscNoRecomp'), we construct the -- 'HomeModInfo' by building a new 'ModDetails' from the old -- 'ModIface' (only). } +homeModInfoByteCode :: HomeModInfo -> Maybe Linkable +homeModInfoByteCode = homeMod_bytecode . hm_linkable + +homeModInfoObject :: HomeModInfo -> Maybe Linkable +homeModInfoObject = homeMod_object . hm_linkable + +emptyHomeModInfoLinkable :: HomeModLinkable +emptyHomeModInfoLinkable = HomeModLinkable Nothing Nothing + +-- See Note [Home module build products] +data HomeModLinkable = HomeModLinkable { homeMod_bytecode :: !(Maybe Linkable) + , homeMod_object :: !(Maybe Linkable) } + +instance Outputable HomeModLinkable where + ppr (HomeModLinkable l1 l2) = ppr l1 $$ ppr l2 + +justBytecode :: Linkable -> HomeModLinkable +justBytecode lm = + assertPpr (not (isObjectLinkable lm)) (ppr lm) + $ emptyHomeModInfoLinkable { homeMod_bytecode = Just lm } + +justObjects :: Linkable -> HomeModLinkable +justObjects lm = + assertPpr (isObjectLinkable lm) (ppr lm) + $ emptyHomeModInfoLinkable { homeMod_object = Just lm } + +bytecodeAndObjects :: Linkable -> Linkable -> HomeModLinkable +bytecodeAndObjects bc o = + assertPpr (not (isObjectLinkable bc) && isObjectLinkable o) (ppr bc $$ ppr o) + (HomeModLinkable (Just bc) (Just o)) + + +{- +Note [Home module build products] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +When compiling a home module we can produce some combination of the following +build products. + +1. A byte code linkable, for use with the byte code interpreter. +2. An object file linkable, for linking a final executable or the byte code interpreter + +What we have produced is recorded in the `HomeModLinkable` type. In the case +that these linkables are produced they are stored in the relevant field so that +subsequent modules can retrieve and use them as necessary. + +* `-fbyte-code` will *only* produce a byte code linkable. This is the default in GHCi. +* `-fobject-code` will *only* produce an object file linkable. This is the default in -c and --make mode. +* `-fbyte-code-and-object-code` produces both a byte-code and object file linkable. So both fields are populated. + +Why would you want to produce both an object file and byte code linkable? If you +also want to use `-fprefer-byte-code` then you should probably also use this +flag to make sure that byte code is generated for your modules. + +-} + -- | Helps us find information about modules in the home package type HomePackageTable = DModuleNameEnv HomeModInfo -- Domain = modules in the home unit that have been fully compiled |