reinstate Haddock, closes #20

.github/workflows/nix-haddock-linux.yml

@@ -0,0 +1,31 @@
+name: nix-haddock-linux
+
+# If you need to debug this action, use following action.
+# on: [push, pull_request]
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: cachix/install-nix-action@v7
+    - name: Setup repo
+    - name: Build
+      run: |
+        nix-env -i cachix
+        cachix use tycho01
+        nix-build -A synthesis-docs
+        pwd
+        find result/ |head
+        mkdir public
+        cp -r ./result/share/doc/* public/
+    - name: Deploy
+      if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+      uses: peaceiris/actions-gh-pages@v3
+      with:
+        deploy_key: ${{ secrets.ACTIONS_DEPLOY_KEY }}
+        # personal_token: ${{ secrets.PERSONAL_TOKEN }}
+        # github_token: ${{ secrets.GITHUB_TOKEN }}
+        publish_dir: ./public

nix/haddock-combine.nix

@@ -0,0 +1,59 @@
+{ runCommand, lib, haskellPackages }:
+{ hspkgs # Haskell packages to make documentation for. Only those with a "doc" output will be used.
+  # Note: we do not provide arbitrary additional Haddock options, as these would not be 
+  # applied consistently, since we're reusing the already built Haddock for the packages.
+, prologue ? null # Optionally, a file to be used for the Haddock "--prologue" option.
+}: 
+let 
+  hsdocs = builtins.map (x: x.doc) (builtins.filter (x: x ? doc) hspkgs); 
+in runCommand "haddock-join" { buildInputs = [ hsdocs ]; } ''
+  # Merge all the docs from the packages. We don't use symlinkJoin because:
+  # - We are going to want to redistribute this, so we don't want any symlinks.
+  # - We want to be selective about what we copy (we don't need the hydra 
+  #   tarballs from the other packages, for example.
+  mkdir -p "$out/share/doc"
+  for pkg in ${lib.concatStringsSep " " hsdocs}; do
+    cp -R $pkg/share/doc/* "$out/share/doc"
+  done
+  # We're going to sed all the files so they'd better be writable!
+  chmod -R +w $out/share/doc
+
+  # We're now going to rewrite all the pre-generated Haddock HTML output
+  # so that links point to the appropriate place within our combined output,
+  # rather than into the store.
+  root=$out/share/doc
+  for f in $(find $out -name "*.html"); do
+    # Replace all links to the docs we're processing with relative links 
+    # to the root of the doc directory we're creating - the rest of the link is
+    # the same.
+    # Also, it's not a a file:// link now because it's a relative URL instead
+    # of an absolute one.
+    relpath=$(realpath --relative-to=$(dirname $f) --no-symlinks $root)
+    pkgsRegex="${"file://(" + (lib.concatStringsSep "|" hsdocs) + ")/share/doc"}"
+    sed -i -r "s,$pkgsRegex,$relpath,g" "$f"
+    # Now also replace the index/contents links so they point to (what will be) 
+    # the combined ones instead.
+    # Match the enclosing quotes to make sure the regex for index.html doesn't also match
+    # the trailing part of doc-index.html
+    sed -i -r "s,\"index\.html\",\"$relpath/share/doc/index.html\",g" "$f"
+    sed -i -r "s,\"doc-index\.html\",\"$relpath/share/doc/doc-index.html\",g" "$f"
+  done
+
+  # Move to the docdir. We do this so that we can give relative docpaths to
+  # Haddock so it will generate relative (relocatable) links in the index.
+  cd $out/share/doc
+  # Collect all the interface files and their docpaths (in this case
+  # we can just use the enclosing directory).
+  interfaceOpts=()
+  for interfaceFile in $(find . -name "*.haddock"); do
+    docdir=$(dirname $interfaceFile)
+    interfaceOpts+=("--read-interface=$docdir,$interfaceFile")
+  done
+
+  # Generate the contents and index
+  ${haskellPackages.ghc}/bin/haddock \
+    --gen-contents \
+    --gen-index \
+    ${lib.optionalString (prologue != null) "--prologue ${prologue}"} \
+    "''${interfaceOpts[@]}"
+''

nix/shared.nix

@@ -80,6 +80,16 @@ in
       synthesis_cudatoolkit_10_1
     ;
 
+    synthesis-docs = (
+      (import ./haddock-combine.nix {
+        runCommand = pkgs.runCommand;
+        lib = pkgs.lib;
+        haskellPackages = pkgs.haskellPackages;
+      }) {hspkgs = [
+            synthesis_cpu
+          ];
+         }
+    );
     shell-synthesis_cpu              = (doBenchmark base-compiler.synthesis_cpu).env.overrideAttrs(fixmkl);
     shell-synthesis_cudatoolkit_9_2  = (doBenchmark base-compiler.synthesis_cudatoolkit_9_2).env.overrideAttrs(fixmkl);
     shell-synthesis_cudatoolkit_10_1 = (doBenchmark base-compiler.synthesis_cudatoolkit_10_1).env.overrideAttrs(fixmkl);