From 735f9d6bac316a0c1c68a8b49bba465f07b01cdd Mon Sep 17 00:00:00 2001
From: Sylvain Henry <sylvain@haskus.fr>
Date: Mon, 29 Jun 2020 19:58:56 +0200
Subject: [PATCH] Replace ghcWithNativeCodeGen with a proper Backend datatype
* Represent backends with a `Backend` datatype in GHC.Driver.Backend
* Don't detect the default backend to use for the target platform at
compile time in Hadrian/make but at runtime. It makes "Settings"
simpler and it is a step toward making GHC multi-target.
* The latter change also fixes hadrian which has not been updated to
take into account that the NCG now supports AIX and PPC64 (cf
df26b95559fd467abc0a3a4151127c95cb5011b9 and
d3c1dda60d0ec07fc7f593bfd83ec9457dfa7984)
* Also we don't treat iOS specifically anymore (cf
cb4878ffd18a3c70f98bdbb413cd3c4d1f054e1f)
---
compiler/GHC/Cmm/CLabel.hs | 2 +-
compiler/GHC/Driver/Backend.hs | 43 ++++++++++++++++++++++++++++++
compiler/GHC/Driver/Session.hs | 42 +++++++++++++++++------------
compiler/GHC/Settings/IO.hs | 2 --
compiler/ghc.cabal.in | 1 +
distrib/cross-port | 1 -
distrib/hc-build | 1 -
hadrian/src/Oracles/Flag.hs | 9 +------
hadrian/src/Rules/Generate.hs | 1 -
includes/ghc.mk | 1 -
libraries/ghc-boot/GHC/Platform.hs | 1 -
mk/config.mk.in | 13 ---------
12 files changed, 71 insertions(+), 46 deletions(-)
create mode 100644 compiler/GHC/Driver/Backend.hs
diff --git a/compiler/GHC/Cmm/CLabel.hs b/compiler/GHC/Cmm/CLabel.hs
index 6c9810c10e3..47487c7ebe8 100644
--- a/compiler/GHC/Cmm/CLabel.hs
+++ b/compiler/GHC/Cmm/CLabel.hs
@@ -1255,7 +1255,7 @@ pprCLabel dflags = \case
where
platform = targetPlatform dflags
- useNCG = platformMisc_ghcWithNativeCodeGen (platformMisc dflags)
+ useNCG = hscTarget dflags == HscAsm
maybe_underscore :: SDoc -> SDoc
maybe_underscore doc =
diff --git a/compiler/GHC/Driver/Backend.hs b/compiler/GHC/Driver/Backend.hs
new file mode 100644
index 00000000000..8f227d2a2b9
--- /dev/null
+++ b/compiler/GHC/Driver/Backend.hs
@@ -0,0 +1,43 @@
+{-# LANGUAGE MultiWayIf #-}
+
+-- | Code generation backends
+module GHC.Driver.Backend
+ ( Backend (..)
+ , platformDefaultBackend
+ , platformNcgSupported
+ )
+where
+
+import GHC.Prelude
+import GHC.Platform
+
+-- | Backend
+data Backend
+ = NCG -- ^ Native code generator backend
+ | LLVM -- ^ LLVM backend
+ | ViaC -- ^ Via-C backend
+ | Interpreter -- ^ Interpreter
+ deriving (Eq,Ord,Show,Read)
+
+-- | Default backend to use for the given platform.
+platformDefaultBackend :: Platform -> Backend
+platformDefaultBackend platform = if
+ | platformUnregisterised platform -> ViaC
+ | platformNcgSupported platform -> NCG
+ | otherwise -> LLVM
+
+
+-- | Is the platform supported by the Native Code Generator?
+platformNcgSupported :: Platform -> Bool
+platformNcgSupported platform = if
+ | platformUnregisterised platform -> False -- NCG doesn't support unregisterised ABI
+ | ncgValidArch -> True
+ | otherwise -> False
+ where
+ ncgValidArch = case platformArch platform of
+ ArchX86 -> True
+ ArchX86_64 -> True
+ ArchPPC -> True
+ ArchPPC_64 {} -> True
+ ArchSPARC -> True
+ _ -> False
diff --git a/compiler/GHC/Driver/Session.hs b/compiler/GHC/Driver/Session.hs
index 04ff23d5feb..7d5c72ba743 100644
--- a/compiler/GHC/Driver/Session.hs
+++ b/compiler/GHC/Driver/Session.hs
@@ -253,6 +253,7 @@ import {-# SOURCE #-} GHC.Unit.State (UnitState, emptyUnitState, UnitDatabase, u
import GHC.Driver.Phases ( Phase(..), phaseInputExt )
import GHC.Driver.Flags
import GHC.Driver.Ways
+import GHC.Driver.Backend
import GHC.Settings.Config
import GHC.Utils.CliOption
import GHC.Driver.CmdLine hiding (WarnReason(..))
@@ -1151,16 +1152,15 @@ instance Outputable PackageFlag where
-- | The 'HscTarget' value corresponding to the default way to create
-- object files on the current platform.
-defaultHscTarget :: Platform -> PlatformMisc -> HscTarget
-defaultHscTarget platform pMisc
- | platformUnregisterised platform = HscC
- | platformMisc_ghcWithNativeCodeGen pMisc = HscAsm
+defaultHscTarget :: Platform -> HscTarget
+defaultHscTarget platform
+ | platformUnregisterised platform = HscC
+ | NCG <- platformDefaultBackend platform = HscAsm
| otherwise = HscLlvm
defaultObjectTarget :: DynFlags -> HscTarget
defaultObjectTarget dflags = defaultHscTarget
(targetPlatform dflags)
- (platformMisc dflags)
data DynLibLoader
= Deployable
@@ -1272,7 +1272,7 @@ defaultDynFlags mySettings llvmConfig =
DynFlags {
ghcMode = CompManager,
ghcLink = LinkBinary,
- hscTarget = defaultHscTarget (sTargetPlatform mySettings) (sPlatformMisc mySettings),
+ hscTarget = defaultHscTarget (sTargetPlatform mySettings),
verbosity = 0,
optLevel = 0,
debugLevel = 0,
@@ -4856,7 +4856,8 @@ compilerInfo dflags
("Target platform", platformMisc_targetPlatformString $ platformMisc dflags),
("Have interpreter", showBool $ platformMisc_ghcWithInterpreter $ platformMisc dflags),
("Object splitting supported", showBool False),
- ("Have native code generator", showBool $ platformMisc_ghcWithNativeCodeGen $ platformMisc dflags),
+ ("Have native code generator", showBool $ platformNcgSupported (targetPlatform dflags)),
+ ("Target default backend", show $ platformDefaultBackend (targetPlatform dflags)),
-- Whether or not we support @-dynamic-too@
("Support dynamic-too", showBool $ not isWindows),
-- Whether or not we support the @-j@ flag with @--make@.
@@ -4951,28 +4952,35 @@ makeDynFlagsConsistent dflags
= let dflags' = gopt_unset dflags Opt_BuildDynamicToo
warn = "-dynamic-too is not supported on Windows"
in loop dflags' warn
+
+ -- Via-C backend only supports unregisterised convention. Switch to a backend
+ -- supporting it if possible.
| hscTarget dflags == HscC &&
not (platformUnregisterised (targetPlatform dflags))
- = if platformMisc_ghcWithNativeCodeGen $ platformMisc dflags
- then let dflags' = dflags { hscTarget = HscAsm }
- warn = "Compiler not unregisterised, so using native code generator rather than compiling via C"
- in loop dflags' warn
- else let dflags' = dflags { hscTarget = HscLlvm }
- warn = "Compiler not unregisterised, so using LLVM rather than compiling via C"
- in loop dflags' warn
+ = case platformDefaultBackend (targetPlatform dflags) of
+ NCG -> let dflags' = dflags { hscTarget = HscAsm }
+ warn = "Target platform doesn't use unregisterised ABI, so using native code generator rather than compiling via C"
+ in loop dflags' warn
+ LLVM -> let dflags' = dflags { hscTarget = HscLlvm }
+ warn = "Target platform doesn't use unregisterised ABI, so using LLVM rather than compiling via C"
+ in loop dflags' warn
+ _ -> pgmError "Compiling via C is only supported with unregisterised ABI but target platform doesn't use it."
| gopt Opt_Hpc dflags && hscTarget dflags == HscInterpreted
= let dflags' = gopt_unset dflags Opt_Hpc
warn = "Hpc can't be used with byte-code interpreter. Ignoring -fhpc."
in loop dflags' warn
+
| hscTarget dflags `elem` [HscAsm, HscLlvm] &&
platformUnregisterised (targetPlatform dflags)
= loop (dflags { hscTarget = HscC })
- "Compiler unregisterised, so compiling via C"
+ "Target platform uses unregisterised ABI, so compiling via C"
+
| hscTarget dflags == HscAsm &&
- not (platformMisc_ghcWithNativeCodeGen $ platformMisc dflags)
+ not (platformNcgSupported $ targetPlatform dflags)
= let dflags' = dflags { hscTarget = HscLlvm }
- warn = "No native code generator, so using LLVM"
+ warn = "Native code generator doesn't support target platform, so using LLVM"
in loop dflags' warn
+
| not (osElfTarget os) && gopt Opt_PIE dflags
= loop (gopt_unset dflags Opt_PIE)
"Position-independent only supported on ELF platforms"
diff --git a/compiler/GHC/Settings/IO.hs b/compiler/GHC/Settings/IO.hs
index 956b28d2705..c84bf280bce 100644
--- a/compiler/GHC/Settings/IO.hs
+++ b/compiler/GHC/Settings/IO.hs
@@ -149,7 +149,6 @@ initSettings top_dir = do
let iserv_prog = libexec "ghc-iserv"
ghcWithInterpreter <- getBooleanSetting "Use interpreter"
- ghcWithNativeCodeGen <- getBooleanSetting "Use native code generator"
ghcWithSMP <- getBooleanSetting "Support SMP"
ghcRTSWays <- getSetting "RTS ways"
useLibFFI <- getBooleanSetting "Use LibFFI"
@@ -216,7 +215,6 @@ initSettings top_dir = do
, sPlatformMisc = PlatformMisc
{ platformMisc_targetPlatformString = targetPlatformString
, platformMisc_ghcWithInterpreter = ghcWithInterpreter
- , platformMisc_ghcWithNativeCodeGen = ghcWithNativeCodeGen
, platformMisc_ghcWithSMP = ghcWithSMP
, platformMisc_ghcRTSWays = ghcRTSWays
, platformMisc_libFFI = useLibFFI
diff --git a/compiler/ghc.cabal.in b/compiler/ghc.cabal.in
index 755ef4dab7c..7d896b8ad37 100644
--- a/compiler/ghc.cabal.in
+++ b/compiler/ghc.cabal.in
@@ -162,6 +162,7 @@ Library
GHC.Iface.Ext.Ast
GHC.SysTools.Ar
GHC.SysTools.FileCleanup
+ GHC.Driver.Backend
GHC.Driver.Backpack
GHC.Driver.Backpack.Syntax
GHC.Types.Name.Shape
diff --git a/distrib/cross-port b/distrib/cross-port
index 4a1854135a1..29dd804e825 100644
--- a/distrib/cross-port
+++ b/distrib/cross-port
@@ -62,7 +62,6 @@ if [ ! -f b2-stamp ]; then
# code too. If you don't want it to, then comment out this line:
echo "GhcUnregisterised = YES" >> mk/build.mk
echo "SRC_HC_OPTS += -keep-hc-file -fvia-C" >> mk/build.mk
- echo "GhcWithNativeCodeGen = NO" >> mk/build.mk
echo "GhcWithInterpreter = NO" >> mk/build.mk
# we just need to build the compiler and utils...
diff --git a/distrib/hc-build b/distrib/hc-build
index 13afaa7adb9..ad39854d9e4 100644
--- a/distrib/hc-build
+++ b/distrib/hc-build
@@ -31,7 +31,6 @@ case "$configopts" in
cat >>mk/build.mk <<END
GhcUnregisterised=YES
GhcWithInterpreter=NO
-GhcWithNativeCodeGen=NO
GhcLibWays=
GhcWithSMP=NO
END
diff --git a/hadrian/src/Oracles/Flag.hs b/hadrian/src/Oracles/Flag.hs
index 2de81cfdd6e..4f88af64325 100644
--- a/hadrian/src/Oracles/Flag.hs
+++ b/hadrian/src/Oracles/Flag.hs
@@ -2,7 +2,7 @@
module Oracles.Flag (
Flag (..), flag, getFlag, platformSupportsSharedLibs,
- ghcWithNativeCodeGen, targetSupportsSMP
+ targetSupportsSMP
) where
import Hadrian.Oracles.TextFile
@@ -77,10 +77,3 @@ targetSupportsSMP = do
, ver < ARMv7 -> return False
| goodArch -> return True
| otherwise -> return False
-
-ghcWithNativeCodeGen :: Action Bool
-ghcWithNativeCodeGen = do
- goodArch <- anyTargetArch ["i386", "x86_64", "sparc", "powerpc"]
- badOs <- anyTargetOs ["ios", "aix"]
- ghcUnreg <- flag GhcUnregisterised
- return $ goodArch && not badOs && not ghcUnreg
diff --git a/hadrian/src/Rules/Generate.hs b/hadrian/src/Rules/Generate.hs
index 62a7bbebbc7..e2097d8d795 100644
--- a/hadrian/src/Rules/Generate.hs
+++ b/hadrian/src/Rules/Generate.hs
@@ -315,7 +315,6 @@ generateSettings = do
, ("BigNum backend", getBignumBackend)
, ("Use interpreter", expr $ yesNo <$> ghcWithInterpreter)
- , ("Use native code generator", expr $ yesNo <$> ghcWithNativeCodeGen)
, ("Support SMP", expr $ yesNo <$> targetSupportsSMP)
, ("RTS ways", unwords . map show <$> getRtsWays)
, ("Tables next to code", expr $ yesNo <$> flag TablesNextToCode)
diff --git a/includes/ghc.mk b/includes/ghc.mk
index cb95d9089bb..efae7e3a22d 100644
--- a/includes/ghc.mk
+++ b/includes/ghc.mk
@@ -250,7 +250,6 @@ $(includes_SETTINGS) : includes/Makefile | $$(dir $$@)/.
@echo
@echo ',("bignum backend", "$(BIGNUM_BACKEND)")' >> $@
@echo ',("Use interpreter", "$(GhcWithInterpreter)")' >> $@
- @echo ',("Use native code generator", "$(GhcWithNativeCodeGen)")' >> $@
@echo ',("Support SMP", "$(GhcWithSMP)")' >> $@
@echo ',("RTS ways", "$(GhcRTSWays)")' >> $@
@echo ',("Tables next to code", "$(TablesNextToCode)")' >> $@
diff --git a/libraries/ghc-boot/GHC/Platform.hs b/libraries/ghc-boot/GHC/Platform.hs
index 46387c52a22..326b93f9fab 100644
--- a/libraries/ghc-boot/GHC/Platform.hs
+++ b/libraries/ghc-boot/GHC/Platform.hs
@@ -295,7 +295,6 @@ data PlatformMisc = PlatformMisc
{ -- TODO Recalculate string from richer info?
platformMisc_targetPlatformString :: String
, platformMisc_ghcWithInterpreter :: Bool
- , platformMisc_ghcWithNativeCodeGen :: Bool
, platformMisc_ghcWithSMP :: Bool
, platformMisc_ghcRTSWays :: String
, platformMisc_libFFI :: Bool
diff --git a/mk/config.mk.in b/mk/config.mk.in
index 9c4cdc95735..4269dec785f 100644
--- a/mk/config.mk.in
+++ b/mk/config.mk.in
@@ -173,19 +173,6 @@ endif
#
GhcUnregisterised=@Unregisterised@
-# Build a compiler with a native code generator backend
-# (as well as a C backend)
-#
-# Target platforms supported:
-# i386, powerpc, powerpc64, sparc
-# IOS is not supported
-ArchSupportsNCG=$(strip $(patsubst $(TargetArch_CPP), YES, $(findstring $(TargetArch_CPP), i386 x86_64 powerpc powerpc64 powerpc64le sparc)))
-OsSupportsNCG=$(strip $(patsubst $(TargetOS_CPP), YES, $(patsubst ios,,$(TargetOS_CPP))))
-
-GhcWithNativeCodeGen := $(strip\
- $(if $(filter YESYESNO,\
- $(OsSupportsNCG)$(ArchSupportsNCG)$(GhcUnregisterised)),YES,NO))
-
# ArchSupportsSMP should be set iff there is support for that arch in
# includes/stg/SMP.h
ifeq "$(TargetArch_CPP)" "arm"
--
GitLab