Consolidate `TablesNextToCode` and `GhcUnreigsterised` in configure (#15548)

`TablesNextToCode` is now a substituted by configure, where it has the
correct defaults and error handling. Nowhere else needs to duplicate
that, though we may want the compiler to to guard against bogus settings
files.

I renamed it from `GhcEnableTablesNextToCode` to `TablesNextToCode` to:

 - Help me guard against any unfixed usages

 - Remove any lingering connotation that this flag needs to be combined
   with `GhcUnreigsterised`.

Original reviewers:

Original subscribers: TerrorJack, rwbarton, carter

Original Differential Revision: https://phabricator.haskell.org/D5082

5 files changed, 10 insertions, 11 deletions

diff --git a/hadrian/cfg/system.config.in b/hadrian/cfg/system.config.in
index 5bdb322551..2380baf9c0 100644
--- a/hadrian/cfg/system.config.in
+++ b/hadrian/cfg/system.config.in
@@ -43,6 +43,7 @@ hs-cpp-args         = @HaskellCPPArgs@
 
 solaris-broken-shld  = @SOLARIS_BROKEN_SHLD@
 ghc-unregisterised   = @Unregisterised@
+tables-next-to-code  = @TablesNextToCode@
 ghc-source-path      = @hardtop@
 leading-underscore   = @LeadingUnderscore@
 
diff --git a/hadrian/src/Oracles/Flag.hs b/hadrian/src/Oracles/Flag.hs
index 4f5116bf41..075a1bfe23 100644
--- a/hadrian/src/Oracles/Flag.hs
+++ b/hadrian/src/Oracles/Flag.hs
@@ -13,6 +13,7 @@ data Flag = ArSupportsAtFile
           | CrossCompiling
           | GccIsClang
           | GhcUnregisterised
+          | TablesNextToCode
           | GmpInTree
           | GmpFrameworkPref
           | LeadingUnderscore
@@ -30,6 +31,7 @@ flag f = do
             CrossCompiling     -> "cross-compiling"
             GccIsClang         -> "gcc-is-clang"
             GhcUnregisterised  -> "ghc-unregisterised"
+            TablesNextToCode   -> "tables-next-to-code"
             GmpInTree          -> "intree-gmp"
             GmpFrameworkPref   -> "gmp-framework-preferred"
             LeadingUnderscore  -> "leading-underscore"
diff --git a/hadrian/src/Oracles/Setting.hs b/hadrian/src/Oracles/Setting.hs
index 408f9e3422..51ccc729a3 100644
--- a/hadrian/src/Oracles/Setting.hs
+++ b/hadrian/src/Oracles/Setting.hs
@@ -1,7 +1,7 @@
 module Oracles.Setting (
     configFile, Setting (..), SettingList (..), setting, settingList, getSetting,
     getSettingList,  anyTargetPlatform, anyTargetOs, anyTargetArch, anyHostOs,
-    ghcWithInterpreter, ghcEnableTablesNextToCode, useLibFFIForAdjustors,
+    ghcWithInterpreter, useLibFFIForAdjustors,
     ghcCanonVersion, cmdLineLengthLimit, hostSupportsRPaths, topDirectory,
     libsuf, ghcVersionStage, SettingsFileSetting (..), settingsFileSetting
     ) where
@@ -225,11 +225,6 @@ ghcWithInterpreter = do
                               , "sparc64", "arm" ]
     return $ goodOs && goodArch
 
--- | Check whether the target architecture supports placing info tables next to
--- code. See: https://gitlab.haskell.org/ghc/ghc/wikis/commentary/rts/storage/heap-objects#tables_next_to_code.
-ghcEnableTablesNextToCode :: Action Bool
-ghcEnableTablesNextToCode = notM $ anyTargetArch ["ia64", "powerpc64", "powerpc64le"]
-
 -- | Check to use @libffi@ for adjustors.
 useLibFFIForAdjustors :: Action Bool
 useLibFFIForAdjustors = notM $ anyTargetArch ["i386", "x86_64"]
diff --git a/hadrian/src/Rules/Generate.hs b/hadrian/src/Rules/Generate.hs
index 18e6f9271c..8ad8ead4c7 100644
--- a/hadrian/src/Rules/Generate.hs
+++ b/hadrian/src/Rules/Generate.hs
@@ -313,7 +313,7 @@ generateSettings = do
         , ("Use native code generator", expr $ yesNo <$> ghcWithNativeCodeGen)
         , ("Support SMP", expr $ yesNo <$> ghcWithSMP)
         , ("RTS ways", unwords . map show <$> getRtsWays)
-        , ("Tables next to code", expr $ yesNo <$> ghcEnableTablesNextToCode)
+        , ("Tables next to code", expr $ yesNo <$> flag TablesNextToCode)
         , ("Leading underscore", expr $ yesNo <$> flag LeadingUnderscore)
         , ("Use LibFFI", expr $ yesNo <$> useLibFFIForAdjustors)
         , ("Use Threads", yesNo . any (wayUnit Threaded) <$> getRtsWays)
@@ -373,7 +373,7 @@ generateGhcAutoconfH :: Expr String
 generateGhcAutoconfH = do
     trackGenerateHs
     configHContents  <- expr $ map undefinePackage <$> readFileLines configH
-    tablesNextToCode <- expr ghcEnableTablesNextToCode
+    tablesNextToCode <- getFlag    TablesNextToCode
     ghcUnreg         <- getFlag    GhcUnregisterised
     ccLlvmBackend    <- getSetting CcLlvmBackend
     ccClangBackend   <- getSetting CcClangBackend
diff --git a/hadrian/src/Settings/Packages.hs b/hadrian/src/Settings/Packages.hs
index ecffc58c9d..01c170b68e 100644
--- a/hadrian/src/Settings/Packages.hs
+++ b/hadrian/src/Settings/Packages.hs
@@ -67,7 +67,7 @@ packageArgs = do
             , (any (wayUnit Threaded) rtsWays) ?
               notStage0 ? arg "--ghc-option=-optc-DTHREADED_RTS"
             , ghcWithInterpreter ?
-              ghcEnableTablesNextToCode ?
+              flag TablesNextToCode ?
               notM (flag GhcUnregisterised) ?
               notStage0 ? arg "--ghc-option=-DGHCI_TABLES_NEXT_TO_CODE"
             , ghcWithInterpreter ?
@@ -196,7 +196,7 @@ rtsPackageArgs = package rts ? do
     targetOs       <- getSetting TargetOs
     targetVendor   <- getSetting TargetVendor
     ghcUnreg       <- expr $ yesNo <$> flag GhcUnregisterised
-    ghcEnableTNC   <- expr $ yesNo <$> ghcEnableTablesNextToCode
+    ghcEnableTNC   <- expr $ yesNo <$> flag TablesNextToCode
     rtsWays        <- getRtsWays
     way            <- getWay
     path           <- getBuildPath
@@ -249,7 +249,8 @@ rtsPackageArgs = package rts ? do
             , "-DTargetOS="                  ++ show targetOs
             , "-DTargetVendor="              ++ show targetVendor
             , "-DGhcUnregisterised="         ++ show ghcUnreg
-            , "-DGhcEnableTablesNextToCode=" ++ show ghcEnableTNC ]
+            , "-DTablesNextToCode="          ++ show ghcEnableTNC
+            ]
 
           -- We're after pur performance here. So make sure fast math and
           -- vectorization is enabled.