stdenv: Make it easier to correctly run phases in nix-shell

Currently, it's a bit annoying to run build phases manually inside a
nix-shell. To run say, buildPhase, the invocation that works correctly
in all cases is:

eval "${buildPhase:-buildPhase}"

Which is quite a mouthful and non-obvious. Even worse, the obvious
thing to try, i.e.:

buildPhase

works _sometimes_ (i.e. when the package doesn't have a
`buildPhase = "...";`) but silently does the wrong thing in other cases.

Let's fix this by having the obvious thing work always.

To do that, we simply pull the logic of 'if $buildPhase exists as a variable,
then eval "$buildPhase", else do the default buildPhase' into the
buildPhase() function itself using a common helper:

buildPhase() {
    commonPhaseImpl buildPhase --default defaultBuildPhase --pre-hook preBuild --post-hook postBuild
}

As a bonus, we get to fix another current annoyance/footgun at the same
time, that is setting e.g. `buildPhase = "...";` makes the preBuild and
postBuild hooks not being run anymore.

pkgs/build-support/release/ant-build.nix

@@ -25,11 +25,23 @@ stdenv.mkDerivation (
     inherit jre ant;
     showBuildStats = true;
 
-    postPhases =
-      ["generateWrappersPhase" "finalPhase"];
+    preHook = ''
+      antSetupPhase() {
+        commonPhaseImpl antSetupPhase
+      }
+
+      generateWrappersPhase() {
+        commonPhaseImpl generateWrappersPhase
+      }
+
+      finalPhase() {
+        commonPhaseImpl finalPhase
+      }
+    '';
+
+    postPhases = ["generateWrappersPhase" "finalPhase"];
 
-    prePhases =
-      ["antSetupPhase"];
+    prePhases = ["antSetupPhase"];
 
     antSetupPhase = with stdenv.lib; ''
       if test "$hydraAntLogger" != "" ; then

pkgs/build-support/release/debian-build.nix

@@ -28,6 +28,16 @@ vmTools.runInLinuxImage (stdenv.mkDerivation (
   {
     name = name + "-" + diskImage.name + (if src ? version then "-" + src.version else "");
 
+    preHook = ''
+      installExtraDebsPhase() {
+        commonPhaseImpl installExtraDebsPhase
+      }
+
+      sysInfoPhase() {
+        commonPhaseImpl sysInfoPhase
+      }
+    '';
+
     # !!! cut&paste from rpm-build.nix
     postHook = ''
       . ${./functions.sh}

pkgs/build-support/release/nix-build.nix

@@ -109,6 +109,14 @@ stdenv.mkDerivation (
         alias make="scan-build -o _clang_analyze_$name --html-title='Scan results for $name' make"
       fi
 
+      initPhase() {
+        commonPhaseImpl initPhase
+      }
+
+      finalPhase() {
+        commonPhaseImpl finalPhase
+      }
+
       ${preHook}
     '';
 

pkgs/build-support/setup-hooks/autoreconf.sh

@@ -1,7 +1,9 @@
 preConfigurePhases+=" autoreconfPhase"
 
 autoreconfPhase() {
-    runHook preAutoreconf
+    commonPhaseImpl autoreconfPhase --default defaultAutoreconfPhase --pre-hook preAutoreconf --post-hook postAutoreconf
+}
+
+defaultAutoreconfPhase() {
     autoreconf ${autoreconfFlags:---install --force --verbose}
-    runHook postAutoreconf
 }

pkgs/build-support/setup-hooks/gog-unpack.sh

@@ -1,11 +1,11 @@
 unpackPhase="unpackGog"
 
 unpackGog() {
-    runHook preUnpackGog
+    commonPhaseImpl unpackGog --default defaultUnpackGog --pre-hook preUnpackGog --post-hook postUnpackGog
+}
 
+defaultUnpackGog() {
     innoextract --silent --extract --exclude-temp "${src}"
 
     find . -depth -print -execdir rename -f 'y/A-Z/a-z/' '{}' \;
-
-    runHook postUnpackGog
 }

pkgs/development/haskell-modules/generic-builder.nix

@@ -237,6 +237,20 @@ stdenv.mkDerivation ({
 
   LANG = "en_US.UTF-8";         # GHC needs the locale configured during the Haddock phase.
 
+  preHook = ''
+    setupCompilerEnvironmentPhase() {
+      commonPhaseImpl setupCompilerEnvironmentPhase --pre-hook preSetupCompilerEnvironment --post-hook postSetupCompilerEnvironment
+    }
+
+    compileBuildDriverPhase() {
+      commonPhaseImpl compileBuildDriverPhase --pre-hook preCompileBuildDriver --post-hook postCompileBuildDriver
+    }
+
+    haddockPhase() {
+      commonPhaseImpl haddockPhase --pre-hook preHaddock --post-hook postHaddock
+    }
+  '';
+
   prePatch = optionalString (editedCabalFile != null) ''
     echo "Replace Cabal file with edited version from ${newCabalFileUrl}."
     cp ${newCabalFile} ${pname}.cabal

pkgs/development/ruby-modules/gem/default.nix

@@ -117,7 +117,7 @@ stdenv.mkDerivation ((builtins.removeAttrs attrs ["source"]) // {
     else
       # Fall back to the original thing for everything else.
       dontBuild=""
-      preUnpack="" postUnpack="" unpackPhase
+      preUnpack="" postUnpack="" defaultUnpackPhase
     fi
 
     runHook postUnpack