[Git][ghc/ghc][wip/romes/hardwire-ghc-unit-id] Hardwire a better unit-id for ghc
Rodrigo Mesquita (@alt-romes)
gitlab at gitlab.haskell.org
Mon Mar 13 16:51:48 UTC 2023
Rodrigo Mesquita pushed to branch wip/romes/hardwire-ghc-unit-id at Glasgow Haskell Compiler / GHC
Commits:
702bd403 by romes at 2023-03-13T16:51:20+00:00
Hardwire a better unit-id for ghc
Previously, the unit-id of ghc-the-library was fixed as `ghc`.
This was done primarily because the compiler must know the unit-id of
some packages (including ghc) a-priori to define wired-in names.
However, as seen in #20742, a reinstallable `ghc` whose unit-id is fixed
to `ghc` might result in subtle bugs when different ghc's interact.
A good example of this is having GHC_A load a plugin compiled by GHC_B,
where GHC_A and GHC_B are linked to ghc-libraries that are ABI
incompatible. Without a distinction between the unit-id of the ghc library
GHC_A is linked against and the ghc library the plugin it is loading was
compiled against, we can't check compatibility.
This patch gives a slightly better unit-id to ghc (ghc-version) by
(1) Not setting -this-unit-id to ghc, but rather to the new unit-id (modulo stage0)
(2) Adding a definition to `GHC.Version` whose value is the new unit-id.
This unit-id definition is imported by `GHC.Unit.Types` and used to
set the wired-in unit-id of "ghc", which was previously fixed to "ghc"
The commits following this one will improve the unit-id with a
cabal-style package hash, ensure cabal-built ghcs also correctly use
a better unit-id, and check compatibility when loading plugins.
- - - - -
6 changed files:
- compiler/GHC/Driver/Session.hs
- compiler/GHC/Unit/Types.hs
- compiler/ghc.cabal.in
- hadrian/src/Rules/Generate.hs
- hadrian/src/Settings/Builders/Cabal.hs
- hadrian/src/Settings/Builders/Ghc.hs
Changes:
=====================================
compiler/GHC/Driver/Session.hs
=====================================
@@ -4703,6 +4703,7 @@ compilerInfo dflags
("Project Patch Level", cProjectPatchLevel),
("Project Patch Level1", cProjectPatchLevel1),
("Project Patch Level2", cProjectPatchLevel2),
+ ("Project Unit Id", cProjectUnitId),
("Booter version", cBooterVersion),
("Stage", cStage),
("Build platform", cBuildPlatformString),
=====================================
compiler/GHC/Unit/Types.hs
=====================================
@@ -99,6 +99,7 @@ import GHC.Data.FastString
import GHC.Utils.Encoding
import GHC.Utils.Fingerprint
import GHC.Utils.Misc
+import GHC.Version (cProjectUnitId)
import Control.DeepSeq
import Data.Data
@@ -597,7 +598,7 @@ primUnitId = UnitId (fsLit "ghc-prim")
bignumUnitId = UnitId (fsLit "ghc-bignum")
baseUnitId = UnitId (fsLit "base")
rtsUnitId = UnitId (fsLit "rts")
-thisGhcUnitId = UnitId (fsLit "ghc")
+thisGhcUnitId = UnitId (fsLit cProjectUnitId)
interactiveUnitId = UnitId (fsLit "interactive")
thUnitId = UnitId (fsLit "template-haskell")
=====================================
compiler/ghc.cabal.in
=====================================
@@ -57,6 +57,12 @@ Flag build-tool-depends
Description: Use build-tool-depends
Default: True
+-- While the boot compiler fixes ghc's unit-id to `ghc`, the stage0 compiler must still be compiled with `-this-unit-id ghc`
+Flag hadrian-stage0
+ Description: Enable if compiling the stage0 compiler with hadrian
+ Default: False
+ Manual: True
+
Library
Default-Language: Haskell2010
Exposed: False
@@ -136,9 +142,10 @@ Library
Include-Dirs: .
- -- We need to set the unit id to ghc (without a version number)
- -- as it's magic.
- GHC-Options: -this-unit-id ghc
+ if flag(hadrian-stage0)
+ -- We need to set the unit id to ghc (without a version number)
+ -- as it's magic.
+ GHC-Options: -this-unit-id ghc
c-sources:
cbits/cutils.c
=====================================
hadrian/src/Rules/Generate.hs
=====================================
@@ -533,6 +533,13 @@ generateVersionHs = do
cProjectPatchLevel <- getSetting ProjectPatchLevel
cProjectPatchLevel1 <- getSetting ProjectPatchLevel1
cProjectPatchLevel2 <- getSetting ProjectPatchLevel2
+ -- ROMES:TODO: First we attempt a fixed unit-id with version but without hash.
+ -- We now use a more informative
+ -- unit-id for ghc. This same logic must be done
+ -- when passing -this-unit-id when building ghc (at
+ -- stage0 one must pass -this-unit-id ghc).
+ let cProjectUnitId = "ghc-" ++ cProjectVersion
+
return $ unlines
[ "module GHC.Version where"
, ""
@@ -555,6 +562,9 @@ generateVersionHs = do
, ""
, "cProjectPatchLevel2 :: String"
, "cProjectPatchLevel2 = " ++ show cProjectPatchLevel2
+ , ""
+ , "cProjectUnitId :: String"
+ , "cProjectUnitId = " ++ show cProjectUnitId
]
-- | Generate @Platform/Host.hs@ files.
=====================================
hadrian/src/Settings/Builders/Cabal.hs
=====================================
@@ -115,6 +115,12 @@ commonCabalArgs stage = do
, arg "--htmldir"
, arg $ "${pkgroot}/../../doc/html/libraries/" ++ package_id
+ -- ROMES: While the boot compiler is not updated wrt -this-unit-id
+ -- not being fixed to `ghc`, when building stage0, we must set
+ -- -this-unit-id to `ghc` because the boot compiler expects that.
+ -- We do it through a cabal flag in ghc.cabal
+ , stage0 ? arg "-f+hadrian-stage0"
+
-- These trigger a need on each dependency, so every important to need
-- them in parallel or it linearises the build of Ghc and GhcPkg
, withStageds [Ghc CompileHs, GhcPkg Update, Cc CompileC, Ar Pack]
=====================================
hadrian/src/Settings/Builders/Ghc.hs
=====================================
@@ -245,8 +245,19 @@ wayGhcArgs = do
packageGhcArgs :: Args
packageGhcArgs = do
+ stage <- getStage
package <- getPackage
- ghc_ver <- readVersion <$> (expr . ghcVersionStage =<< getStage)
+ ghc_ver <- readVersion <$> expr (ghcVersionStage stage)
+ -- ROMES: Until the boot compiler no longer needs ghc's
+ -- unit-id to be "ghc", the stage0 compiler must be built
+ -- with `-this-unit-id ghc`, while the wired-in unit-id of
+ -- ghc is correctly set to the unit-id we'll generate for
+ -- stage1 (set in generateVersionHs in Rules.Generate).
+ --
+ -- However, we don't need to set the unit-id of "ghc" to "ghc" when
+ -- building stage0 because we have a flag in compiler/ghc.cabal.in that is
+ -- sets `-this-unit-id ghc` when hadrian is building stage0, which will
+ -- overwrite this one.
pkgId <- expr $ pkgIdentifier package
mconcat [ arg "-hide-all-packages"
, arg "-no-user-package-db"
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/702bd4035e70005e010177988f23e4eea65d7631
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/702bd4035e70005e010177988f23e4eea65d7631
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