nixpkgs/nixos/lib/make-options-doc/default.nix
Maximilian Bosch 6d19c04416
nixos/manual: improve error message for invalid values in `relatedPackages'
As reported in NixOS discourse[1], tracking down invalid values in
`relatedPackages'[2] (i.e. list-items that don't exist in `pkgs`) is
fairly hard as the message "Invalid package attribute path `foobar'"
is quite unhelpful and the trace doesn't point to the source of the
problem either.

This patch improves the error message by mentioning that the issue is an
invalid `relatedPackages`-declaration in $optionName.

[1] https://discourse.nixos.org/t/invalid-package-attribute-path-nextcloud19/8403/9
[2] https://nixos.org/nixpkgs/manual/#sec-functions-library-options
2020-08-03 16:37:59 +02:00

169 lines
6 KiB
Nix

/* Generate JSON, XML and DocBook documentation for given NixOS options.
Minimal example:
{ pkgs, }:
let
eval = import (pkgs.path + "/nixos/lib/eval-config.nix") {
baseModules = [
../module.nix
];
modules = [];
};
in pkgs.nixosOptionsDoc {
options = eval.options;
}
*/
{ pkgs
, lib
, options
, transformOptions ? lib.id # function for additional tranformations of the options
, revision ? "" # Specify revision for the options
}:
let
# Replace functions by the string <function>
substFunction = x:
if builtins.isAttrs x then lib.mapAttrs (name: substFunction) x
else if builtins.isList x then map substFunction x
else if lib.isFunction x then "<function>"
else x;
optionsListDesc = lib.flip map optionsListVisible
(opt: transformOptions opt
// lib.optionalAttrs (opt ? example) { example = substFunction opt.example; }
// lib.optionalAttrs (opt ? default) { default = substFunction opt.default; }
// lib.optionalAttrs (opt ? type) { type = substFunction opt.type; }
// lib.optionalAttrs (opt ? relatedPackages && opt.relatedPackages != []) { relatedPackages = genRelatedPackages opt.relatedPackages opt.name; }
);
# Generate DocBook documentation for a list of packages. This is
# what `relatedPackages` option of `mkOption` from
# ../../../lib/options.nix influences.
#
# Each element of `relatedPackages` can be either
# - a string: that will be interpreted as an attribute name from `pkgs`,
# - a list: that will be interpreted as an attribute path from `pkgs`,
# - an attrset: that can specify `name`, `path`, `package`, `comment`
# (either of `name`, `path` is required, the rest are optional).
genRelatedPackages = packages: optName:
let
unpack = p: if lib.isString p then { name = p; }
else if lib.isList p then { path = p; }
else p;
describe = args:
let
title = args.title or null;
name = args.name or (lib.concatStringsSep "." args.path);
path = args.path or [ args.name ];
package = args.package or (lib.attrByPath path (throw "Invalid package attribute path `${toString path}' found while evaluating `relatedPackages' of option `${optName}'") pkgs);
in "<listitem>"
+ "<para><literal>${lib.optionalString (title != null) "${title} aka "}pkgs.${name} (${package.meta.name})</literal>"
+ lib.optionalString (!package.meta.available) " <emphasis>[UNAVAILABLE]</emphasis>"
+ ": ${package.meta.description or "???"}.</para>"
+ lib.optionalString (args ? comment) "\n<para>${args.comment}</para>"
# Lots of `longDescription's break DocBook, so we just wrap them into <programlisting>
+ lib.optionalString (package.meta ? longDescription) "\n<programlisting>${package.meta.longDescription}</programlisting>"
+ "</listitem>";
in "<itemizedlist>${lib.concatStringsSep "\n" (map (p: describe (unpack p)) packages)}</itemizedlist>";
# Custom "less" that pushes up all the things ending in ".enable*"
# and ".package*"
optionLess = a: b:
let
ise = lib.hasPrefix "enable";
isp = lib.hasPrefix "package";
cmp = lib.splitByAndCompare ise lib.compare
(lib.splitByAndCompare isp lib.compare lib.compare);
in lib.compareLists cmp a.loc b.loc < 0;
# Remove invisible and internal options.
optionsListVisible = lib.filter (opt: opt.visible && !opt.internal) (lib.optionAttrSetToDocList options);
# Customly sort option list for the man page.
optionsList = lib.sort optionLess optionsListDesc;
# Convert the list of options into an XML file.
optionsXML = builtins.toFile "options.xml" (builtins.toXML optionsList);
optionsNix = builtins.listToAttrs (map (o: { name = o.name; value = removeAttrs o ["name" "visible" "internal"]; }) optionsList);
# TODO: declarations: link to github
singleAsciiDoc = name: value: ''
== ${name}
${value.description}
[discrete]
=== details
Type:: ${value.type}
${ if lib.hasAttr "default" value
then ''
Default::
+
----
${builtins.toJSON value.default}
----
''
else "No Default:: {blank}"
}
${ if value.readOnly
then "Read Only:: {blank}"
else ""
}
${ if lib.hasAttr "example" value
then ''
Example::
+
----
${builtins.toJSON value.example}
----
''
else "No Example:: {blank}"
}
'';
in {
inherit optionsNix;
optionsAsciiDoc = lib.concatStringsSep "\n" (lib.mapAttrsToList singleAsciiDoc optionsNix);
optionsJSON = pkgs.runCommand "options.json"
{ meta.description = "List of NixOS options in JSON format";
buildInputs = [ pkgs.brotli ];
}
''
# Export list of options in different format.
dst=$out/share/doc/nixos
mkdir -p $dst
cp ${builtins.toFile "options.json" (builtins.unsafeDiscardStringContext (builtins.toJSON optionsNix))} $dst/options.json
brotli -9 < $dst/options.json > $dst/options.json.br
mkdir -p $out/nix-support
echo "file json $dst/options.json" >> $out/nix-support/hydra-build-products
echo "file json-br $dst/options.json.br" >> $out/nix-support/hydra-build-products
''; # */
optionsDocBook = pkgs.runCommand "options-docbook.xml" {} ''
optionsXML=${optionsXML}
if grep /nixpkgs/nixos/modules $optionsXML; then
echo "The manual appears to depend on the location of Nixpkgs, which is bad"
echo "since this prevents sharing via the NixOS channel. This is typically"
echo "caused by an option default that refers to a relative path (see above"
echo "for hints about the offending path)."
exit 1
fi
${pkgs.libxslt.bin}/bin/xsltproc \
--stringparam revision '${revision}' \
-o intermediate.xml ${./options-to-docbook.xsl} $optionsXML
${pkgs.libxslt.bin}/bin/xsltproc \
-o "$out" ${./postprocess-option-descriptions.xsl} intermediate.xml
'';
}