Revert "Remove old code"

This reverts commit 2922479.

Author: hamishmack

compiler/ghc/default.nix

@@ -274,6 +274,7 @@ let
           then ../../materialized/${compiler-nix-name}/hadrian-ghc98
         else ../../materialized/${compiler-nix-name}/hadrian-ghc99;
       modules = [{
+        reinstallableLibGhc = false;
         # Apply the patches in a way that does not require using something
         # like `srcOnly`. The problem with `pkgs.srcOnly` was that it had to run
         # on a platform at eval time.

modules/component-driver.nix

@@ -26,6 +26,12 @@ in
       merge = _loc: defs: lib.last (lib.getValues defs);
     };
   };
+
+  options.reinstallableLibGhc = lib.mkOption {
+    type = lib.types.bool;
+    default = !pkgs.stdenv.hostPlatform.isGhcjs;
+    description = "Is lib:ghc reinstallable?";
+  };
   options.setup-depends = lib.mkOption {
     type = lib.types.listOf lib.types.unspecified;
     default = [];
@@ -52,10 +58,42 @@ in
   #
   # without reinstallable-lib:ghc, this is significantly larger.
 
-  config.nonReinstallablePkgs =
-    ["rts"] ++ config.preExistingPkgs
-      ++ lib.optionals (builtins.compareVersions config.compiler.version "8.11" < 0 && pkgs.stdenv.hostPlatform.isGhcjs) [
-        "ghcjs-prim" "ghcjs-th"];
+  config.nonReinstallablePkgs = if config.preExistingPkgs != []
+   then ["rts"] ++ config.preExistingPkgs
+    ++ lib.optionals (builtins.compareVersions config.compiler.version "8.11" < 0 && pkgs.stdenv.hostPlatform.isGhcjs) [
+      "ghcjs-prim" "ghcjs-th"]
+   else
+    [ "rts" "ghc-prim" "integer-gmp" "integer-simple" "base"
+      "deepseq" "array" "ghc-boot-th" "pretty" "template-haskell"
+      # ghcjs custom packages
+      "ghcjs-prim" "ghcjs-th"
+    ]
+    ++ lib.optionals (builtins.compareVersions config.compiler.version "8.11" >= 0) [
+      "ghc-bignum"]
+    ++ lib.optionals (builtins.compareVersions config.compiler.version "9.1" >= 0) [
+      "system-cxx-std-lib"]
+    ++ lib.optionals (builtins.compareVersions config.compiler.version "9.9" >= 0) [
+      "ghc-internal"]
+    ++ lib.optionals (!config.reinstallableLibGhc) ([
+      "ghc-boot"
+      "ghc" "Cabal" "Win32" "array" "binary" "bytestring" "containers"
+      "directory" "filepath" "ghc-boot" "ghc-compact" "ghc-prim"
+      # "ghci" "haskeline"
+      "hpc"
+      "mtl" "parsec" "process" "text" "time" "transformers"
+      "unix" "xhtml" "terminfo"
+    ]
+    ++ lib.optionals (builtins.compareVersions config.compiler.version "8.11" >= 0) [
+      # stm and exceptions are needed by the GHC package since 9.0.1
+      "stm" "exceptions"]
+    ++ lib.optionals (builtins.compareVersions config.compiler.version "9.8.1" >= 0) [
+      "semaphore-compat"]
+    ++ lib.optionals (builtins.compareVersions config.compiler.version "9.9" >= 0) [
+      "os-string"]
+    )
+    ++ lib.optionals (!config.reinstallableLibGhc || __elem config.compiler.nix-name ["ghc865"]) [
+      "ghc-heap"
+    ];
 
   options.bootPkgs = lib.mkOption {
     type = lib.types.listOf lib.types.str;
@@ -64,7 +102,7 @@ in
   config.bootPkgs =  [
       "rts" "ghc-boot-th"
       "ghcjs-prim"
-   ] ++ lib.optional (builtins.elem "ghc" config.preExistingPkgs) "ghc"
+   ] ++ lib.optional (!config.reinstallableLibGhc) "ghc"
     ++ lib.optionals (
       !__elem config.compiler.nix-name ["ghc865" "ghc881" "ghc882" "ghc883" "ghc884" "ghc8101" "ghc8102" "ghc8103" "ghc8104" "ghc8105" "ghc8106" "ghc8107"]) [
       "ghc-bignum" ]

modules/configuration-nix.nix

@@ -160,6 +160,23 @@ in {
     pkgs.libpcap
   ];
 
+  # Build ghci and ghc with internal interpreter support to make the
+  # `reinstallableLibGhc` build more like the boot version.
+  # See https://github.com/input-output-hk/haskell.nix/issues/1512
+  packages.ghc.flags.ghci = true;
+  packages.ghc.flags.internal-interpreter = true;
+  packages.ghci.flags.ghci = true;
+  packages.ghci.flags.internal-interpreter = true;
+
+  # These flags are set by hadrian.  This would be fine if:
+  # * Haskell.nix respected `pre-existing` packages in `plan.json` and used the hadrian built version.
+  # * If `plan.json` included the flag settings used by `pre-existing` packages.
+  # For now the work around is to set the flags that hadrian does (see hadrian/src/Settings/Packages.hs).
+  packages.unix.flags      = pkgs.lib.optionalAttrs (builtins.compareVersions config.compiler.version "9.9" > 0) { os-string = true; };
+  packages.directory.flags = pkgs.lib.optionalAttrs (builtins.compareVersions config.compiler.version "9.9" > 0) { os-string = true; };
+  packages.Win32.flags     = pkgs.lib.optionalAttrs (builtins.compareVersions config.compiler.version "9.9" > 0) { os-string = true; };
+  packages.hashable.flags  = pkgs.lib.optionalAttrs (builtins.compareVersions config.compiler.version "9.9" > 0) { os-string = true; };
+
   # See https://github.com/Bodigrim/bitvec/pull/61
   packages.bitvec.patches = [
     (fromUntil "1.1.3.0" "1.1.3.0.1" ../patches/bitvec-gmp-fix.patch)

overlays/bootstrap.nix

@@ -1484,6 +1484,7 @@ in {
                 version = "3.2.4";
                 inherit ghcOverride index-state;
                 materialized = ../materialized/bootstrap + "/${buildBootstrapper.compilerNixName}/alex";
+                modules = [{ reinstallableLibGhc = false; }];
                 nix-tools = config.evalPackages.haskell-nix.nix-tools;
             } // args);
             alex = final.haskell-nix.bootstrap.packages.alex-tool {};
@@ -1494,6 +1495,7 @@ in {
                 evalPackages = pkgs.buildPackages;
                 inherit version ghcOverride index-state;
                 materialized = ../materialized/bootstrap + "/${buildBootstrapper.compilerNixName}/happy-${version}";
+                modules = [{ reinstallableLibGhc = false; }];
                 nix-tools = config.evalPackages.haskell-nix.nix-tools;
               } // args);
             happy = final.haskell-nix.bootstrap.packages.happy-tool {};
@@ -1510,6 +1512,7 @@ in {
                 version = "1.24.4";
                 inherit ghcOverride index-state;
                 materialized = ../materialized/bootstrap + "/${buildBootstrapper.compilerNixName}/hscolour";
+                modules = [{ reinstallableLibGhc = false; }];
                 nix-tools = config.evalPackages.haskell-nix.nix-tools;
             } // args)).getComponent "exe:HsColour";
             hscolour = final.haskell-nix.bootstrap.packages.hscolour-tool {};

overlays/ghc-packages.nix

@@ -260,6 +260,7 @@ in rec {
       configureArgs = "--disable-tests --disable-benchmarks --allow-newer='terminfo:base'"; # avoid failures satisfying bytestring package tests dependencies
       modules = [{
         packages.iserv-proxy.patches = [./patches/ghc/ghc-8.10.7-iserv-proxy-load-dlls.patch];
+        reinstallableLibGhc = false;
       }];
     }))
     ghc-extra-pkgs-cabal-projects;

test/plugin/default.nix

@@ -7,6 +7,9 @@ let
     inherit compiler-nix-name evalPackages;
     src = testSrc "plugin";
     cabalProjectLocal = builtins.readFile ../cabal.project.local;
+    modules = [{
+      reinstallableLibGhc = builtins.compareVersions buildPackages.haskell-nix.compiler.${compiler-nix-name}.version "9.8.1" < 0;
+    }];
   };
 
   packages = project.hsPkgs;