mirror of
https://github.com/NixOS/nixpkgs.git
synced 2024-12-13 17:23:08 +00:00
565 lines
22 KiB
Nix
565 lines
22 KiB
Nix
with import ./lists.nix;
|
||
with import ./trivial.nix;
|
||
with import ./attrsets.nix;
|
||
with import ./options.nix;
|
||
with import ./debug.nix;
|
||
with import ./types.nix;
|
||
|
||
rec {
|
||
|
||
/* Evaluate a set of modules. The result is a set of two
|
||
attributes: ‘options’: the nested set of all option declarations,
|
||
and ‘config’: the nested set of all option values.
|
||
!!! Please think twice before adding to this argument list! The more
|
||
that is specified here instead of in the modules themselves the harder
|
||
it is to transparently move a set of modules to be a submodule of another
|
||
config (as the proper arguments need to be replicated at each call to
|
||
evalModules) and the less declarative the module set is. */
|
||
evalModules = { modules
|
||
, prefix ? []
|
||
, # This should only be used for special arguments that need to be evaluated
|
||
# when resolving module structure (like in imports). For everything else,
|
||
# there's _module.args.
|
||
specialArgs ? {}
|
||
, # This would be remove in the future, Prefer _module.args option instead.
|
||
args ? {}
|
||
, # This would be remove in the future, Prefer _module.check option instead.
|
||
check ? true
|
||
}:
|
||
let
|
||
# This internal module declare internal options under the `_module'
|
||
# attribute. These options are fragile, as they are used by the
|
||
# module system to change the interpretation of modules.
|
||
internalModule = rec {
|
||
_file = ./modules.nix;
|
||
|
||
key = _file;
|
||
|
||
options = {
|
||
_module.args = mkOption {
|
||
type = types.attrsOf types.unspecified;
|
||
internal = true;
|
||
description = "Arguments passed to each module.";
|
||
};
|
||
|
||
_module.check = mkOption {
|
||
type = types.bool;
|
||
internal = true;
|
||
default = check;
|
||
description = "Whether to check whether all option definitions have matching declarations.";
|
||
};
|
||
};
|
||
|
||
config = {
|
||
_module.args = args;
|
||
};
|
||
};
|
||
|
||
closed = closeModules (modules ++ [ internalModule ]) ({ inherit config options; lib = import ./.; } // specialArgs);
|
||
|
||
# Note: the list of modules is reversed to maintain backward
|
||
# compatibility with the old module system. Not sure if this is
|
||
# the most sensible policy.
|
||
options = mergeModules prefix (reverseList closed);
|
||
|
||
# Traverse options and extract the option values into the final
|
||
# config set. At the same time, check whether all option
|
||
# definitions have matching declarations.
|
||
# !!! _module.check's value can't depend on any other config values
|
||
# without an infinite recursion. One way around this is to make the
|
||
# 'config' passed around to the modules be unconditionally unchecked,
|
||
# and only do the check in 'result'.
|
||
config = yieldConfig prefix options;
|
||
yieldConfig = prefix: set:
|
||
let res = removeAttrs (mapAttrs (n: v:
|
||
if isOption v then v.value
|
||
else yieldConfig (prefix ++ [n]) v) set) ["_definedNames"];
|
||
in
|
||
if options._module.check.value && set ? _definedNames then
|
||
foldl' (res: m:
|
||
foldl' (res: name:
|
||
if set ? ${name} then res else throw "The option `${showOption (prefix ++ [name])}' defined in `${m.file}' does not exist.")
|
||
res m.names)
|
||
res set._definedNames
|
||
else
|
||
res;
|
||
result = { inherit options config; };
|
||
in result;
|
||
|
||
/* Close a set of modules under the ‘imports’ relation. */
|
||
closeModules = modules: args:
|
||
let
|
||
toClosureList = file: parentKey: imap (n: x:
|
||
if isAttrs x || isFunction x then
|
||
let key = "${parentKey}:anon-${toString n}"; in
|
||
unifyModuleSyntax file key (unpackSubmodule (applyIfFunction key) x args)
|
||
else
|
||
let file = toString x; key = toString x; in
|
||
unifyModuleSyntax file key (applyIfFunction key (import x) args));
|
||
in
|
||
builtins.genericClosure {
|
||
startSet = toClosureList unknownModule "" modules;
|
||
operator = m: toClosureList m.file m.key m.imports;
|
||
};
|
||
|
||
/* Massage a module into canonical form, that is, a set consisting
|
||
of ‘options’, ‘config’ and ‘imports’ attributes. */
|
||
unifyModuleSyntax = file: key: m:
|
||
if m ? config || m ? options then
|
||
let badAttrs = removeAttrs m ["imports" "options" "config" "key" "_file"]; in
|
||
if badAttrs != {} then
|
||
throw "Module `${key}' has an unsupported attribute `${head (attrNames badAttrs)}'. This is caused by assignments to the top-level attributes `config' or `options'."
|
||
else
|
||
{ file = m._file or file;
|
||
key = toString m.key or key;
|
||
imports = m.imports or [];
|
||
options = m.options or {};
|
||
config = m.config or {};
|
||
}
|
||
else
|
||
{ file = m._file or file;
|
||
key = toString m.key or key;
|
||
imports = m.require or [] ++ m.imports or [];
|
||
options = {};
|
||
config = removeAttrs m ["key" "_file" "require" "imports"];
|
||
};
|
||
|
||
applyIfFunction = key: f: args@{ config, options, lib, ... }: if isFunction f then
|
||
let
|
||
# Module arguments are resolved in a strict manner when attribute set
|
||
# deconstruction is used. As the arguments are now defined with the
|
||
# config._module.args option, the strictness used on the attribute
|
||
# set argument would cause an infinite loop, if the result of the
|
||
# option is given as argument.
|
||
#
|
||
# To work-around the strictness issue on the deconstruction of the
|
||
# attributes set argument, we create a new attribute set which is
|
||
# constructed to satisfy the expected set of attributes. Thus calling
|
||
# a module will resolve strictly the attributes used as argument but
|
||
# not their values. The values are forwarding the result of the
|
||
# evaluation of the option.
|
||
requiredArgs = builtins.attrNames (builtins.functionArgs f);
|
||
context = name: ''while evaluating the module argument `${name}' in "${key}":'';
|
||
extraArgs = builtins.listToAttrs (map (name: {
|
||
inherit name;
|
||
value = addErrorContext (context name)
|
||
(args.${name} or config._module.args.${name});
|
||
}) requiredArgs);
|
||
|
||
# Note: we append in the opposite order such that we can add an error
|
||
# context on the explicited arguments of "args" too. This update
|
||
# operator is used to make the "args@{ ... }: with args.lib;" notation
|
||
# works.
|
||
in f (args // extraArgs)
|
||
else
|
||
f;
|
||
|
||
/* We have to pack and unpack submodules. We cannot wrap the expected
|
||
result of the function as we would no longer be able to list the arguments
|
||
of the submodule. (see applyIfFunction) */
|
||
unpackSubmodule = unpack: m: args:
|
||
if isType "submodule" m then
|
||
{ _file = m.file; } // (unpack m.submodule args)
|
||
else unpack m args;
|
||
|
||
packSubmodule = file: m:
|
||
{ _type = "submodule"; file = file; submodule = m; };
|
||
|
||
/* Merge a list of modules. This will recurse over the option
|
||
declarations in all modules, combining them into a single set.
|
||
At the same time, for each option declaration, it will merge the
|
||
corresponding option definitions in all machines, returning them
|
||
in the ‘value’ attribute of each option. */
|
||
mergeModules = prefix: modules:
|
||
mergeModules' prefix modules
|
||
(concatMap (m: map (config: { inherit (m) file; inherit config; }) (pushDownProperties m.config)) modules);
|
||
|
||
mergeModules' = prefix: options: configs:
|
||
listToAttrs (map (name: {
|
||
# We're descending into attribute ‘name’.
|
||
inherit name;
|
||
value =
|
||
let
|
||
loc = prefix ++ [name];
|
||
# Get all submodules that declare ‘name’.
|
||
decls = concatMap (m:
|
||
if m.options ? ${name}
|
||
then [ { inherit (m) file; options = m.options.${name}; } ]
|
||
else []
|
||
) options;
|
||
# Get all submodules that define ‘name’.
|
||
defns = concatMap (m:
|
||
if m.config ? ${name}
|
||
then map (config: { inherit (m) file; inherit config; })
|
||
(pushDownProperties m.config.${name})
|
||
else []
|
||
) configs;
|
||
nrOptions = count (m: isOption m.options) decls;
|
||
# Extract the definitions for this loc
|
||
defns' = map (m: { inherit (m) file; value = m.config.${name}; })
|
||
(filter (m: m.config ? ${name}) configs);
|
||
in
|
||
if nrOptions == length decls then
|
||
let opt = fixupOptionType loc (mergeOptionDecls loc decls);
|
||
in evalOptionValue loc opt defns'
|
||
else if nrOptions != 0 then
|
||
let
|
||
firstOption = findFirst (m: isOption m.options) "" decls;
|
||
firstNonOption = findFirst (m: !isOption m.options) "" decls;
|
||
in
|
||
throw "The option `${showOption loc}' in `${firstOption.file}' is a prefix of options in `${firstNonOption.file}'."
|
||
else
|
||
mergeModules' loc decls defns;
|
||
}) (concatMap (m: attrNames m.options) options))
|
||
// { _definedNames = map (m: { inherit (m) file; names = attrNames m.config; }) configs; };
|
||
|
||
/* Merge multiple option declarations into a single declaration. In
|
||
general, there should be only one declaration of each option.
|
||
The exception is the ‘options’ attribute, which specifies
|
||
sub-options. These can be specified multiple times to allow one
|
||
module to add sub-options to an option declared somewhere else
|
||
(e.g. multiple modules define sub-options for ‘fileSystems’).
|
||
|
||
'loc' is the list of attribute names where the option is located.
|
||
|
||
'opts' is a list of modules. Each module has an options attribute which
|
||
correspond to the definition of 'loc' in 'opt.file'. */
|
||
mergeOptionDecls = loc: opts:
|
||
foldl' (res: opt:
|
||
if opt.options ? default && res ? default ||
|
||
opt.options ? example && res ? example ||
|
||
opt.options ? description && res ? description ||
|
||
opt.options ? apply && res ? apply ||
|
||
# Accept to merge options which have identical types.
|
||
opt.options ? type && res ? type && opt.options.type.name != res.type.name
|
||
then
|
||
throw "The option `${showOption loc}' in `${opt.file}' is already declared in ${showFiles res.declarations}."
|
||
else
|
||
let
|
||
/* Add the modules of the current option to the list of modules
|
||
already collected. The options attribute except either a list of
|
||
submodules or a submodule. For each submodule, we add the file of the
|
||
current option declaration as the file use for the submodule. If the
|
||
submodule defines any filename, then we ignore the enclosing option file. */
|
||
options' = toList opt.options.options;
|
||
coerceOption = file: opt:
|
||
if isFunction opt then packSubmodule file opt
|
||
else packSubmodule file { options = opt; };
|
||
getSubModules = opt.options.type.getSubModules or null;
|
||
submodules =
|
||
if getSubModules != null then map (packSubmodule opt.file) getSubModules ++ res.options
|
||
else if opt.options ? options then map (coerceOption opt.file) options' ++ res.options
|
||
else res.options;
|
||
in opt.options // res //
|
||
{ declarations = res.declarations ++ [opt.file];
|
||
options = submodules;
|
||
}
|
||
) { inherit loc; declarations = []; options = []; } opts;
|
||
|
||
/* Merge all the definitions of an option to produce the final
|
||
config value. */
|
||
evalOptionValue = loc: opt: defs:
|
||
let
|
||
# Add in the default value for this option, if any.
|
||
defs' =
|
||
(optional (opt ? default)
|
||
{ file = head opt.declarations; value = mkOptionDefault opt.default; }) ++ defs;
|
||
|
||
# Handle properties, check types, and merge everything together.
|
||
res =
|
||
if opt.readOnly or false && length defs' > 1 then
|
||
throw "The option `${showOption loc}' is read-only, but it's set multiple times."
|
||
else
|
||
mergeDefinitions loc opt.type defs';
|
||
|
||
# Check whether the option is defined, and apply the ‘apply’
|
||
# function to the merged value. This allows options to yield a
|
||
# value computed from the definitions.
|
||
value =
|
||
if !res.isDefined then
|
||
throw "The option `${showOption loc}' is used but not defined."
|
||
else if opt ? apply then
|
||
opt.apply res.mergedValue
|
||
else
|
||
res.mergedValue;
|
||
|
||
in opt //
|
||
{ value = addErrorContext "while evaluating the option `${showOption loc}':" value;
|
||
definitions = map (def: def.value) res.defsFinal;
|
||
files = map (def: def.file) res.defsFinal;
|
||
inherit (res) isDefined;
|
||
};
|
||
|
||
# Merge definitions of a value of a given type.
|
||
mergeDefinitions = loc: type: defs: rec {
|
||
defsFinal =
|
||
let
|
||
# Process mkMerge and mkIf properties.
|
||
defs' = concatMap (m:
|
||
map (value: { inherit (m) file; inherit value; }) (dischargeProperties m.value)
|
||
) defs;
|
||
|
||
# Process mkOverride properties.
|
||
defs'' = filterOverrides defs';
|
||
|
||
# Sort mkOrder properties.
|
||
defs''' =
|
||
# Avoid sorting if we don't have to.
|
||
if any (def: def.value._type or "" == "order") defs''
|
||
then sortProperties defs''
|
||
else defs'';
|
||
in defs''';
|
||
|
||
# Type-check the remaining definitions, and merge them.
|
||
mergedValue = foldl' (res: def:
|
||
if type.check def.value then res
|
||
else throw "The option value `${showOption loc}' in `${def.file}' is not a ${type.name}.")
|
||
(type.merge loc defsFinal) defsFinal;
|
||
|
||
isDefined = defsFinal != [];
|
||
|
||
optionalValue =
|
||
if isDefined then { value = mergedValue; }
|
||
else {};
|
||
};
|
||
|
||
/* Given a config set, expand mkMerge properties, and push down the
|
||
other properties into the children. The result is a list of
|
||
config sets that do not have properties at top-level. For
|
||
example,
|
||
|
||
mkMerge [ { boot = set1; } (mkIf cond { boot = set2; services = set3; }) ]
|
||
|
||
is transformed into
|
||
|
||
[ { boot = set1; } { boot = mkIf cond set2; services = mkIf cond set3; } ].
|
||
|
||
This transform is the critical step that allows mkIf conditions
|
||
to refer to the full configuration without creating an infinite
|
||
recursion.
|
||
*/
|
||
pushDownProperties = cfg:
|
||
if cfg._type or "" == "merge" then
|
||
concatMap pushDownProperties cfg.contents
|
||
else if cfg._type or "" == "if" then
|
||
map (mapAttrs (n: v: mkIf cfg.condition v)) (pushDownProperties cfg.content)
|
||
else if cfg._type or "" == "override" then
|
||
map (mapAttrs (n: v: mkOverride cfg.priority v)) (pushDownProperties cfg.content)
|
||
else # FIXME: handle mkOrder?
|
||
[ cfg ];
|
||
|
||
/* Given a config value, expand mkMerge properties, and discharge
|
||
any mkIf conditions. That is, this is the place where mkIf
|
||
conditions are actually evaluated. The result is a list of
|
||
config values. For example, ‘mkIf false x’ yields ‘[]’,
|
||
‘mkIf true x’ yields ‘[x]’, and
|
||
|
||
mkMerge [ 1 (mkIf true 2) (mkIf true (mkIf false 3)) ]
|
||
|
||
yields ‘[ 1 2 ]’.
|
||
*/
|
||
dischargeProperties = def:
|
||
if def._type or "" == "merge" then
|
||
concatMap dischargeProperties def.contents
|
||
else if def._type or "" == "if" then
|
||
if def.condition then
|
||
dischargeProperties def.content
|
||
else
|
||
[ ]
|
||
else
|
||
[ def ];
|
||
|
||
/* Given a list of config values, process the mkOverride properties,
|
||
that is, return the values that have the highest (that is,
|
||
numerically lowest) priority, and strip the mkOverride
|
||
properties. For example,
|
||
|
||
[ { file = "/1"; value = mkOverride 10 "a"; }
|
||
{ file = "/2"; value = mkOverride 20 "b"; }
|
||
{ file = "/3"; value = "z"; }
|
||
{ file = "/4"; value = mkOverride 10 "d"; }
|
||
]
|
||
|
||
yields
|
||
|
||
[ { file = "/1"; value = "a"; }
|
||
{ file = "/4"; value = "d"; }
|
||
]
|
||
|
||
Note that "z" has the default priority 100.
|
||
*/
|
||
filterOverrides = defs:
|
||
let
|
||
defaultPrio = 100;
|
||
getPrio = def: if def.value._type or "" == "override" then def.value.priority else defaultPrio;
|
||
highestPrio = foldl' (prio: def: min (getPrio def) prio) 9999 defs;
|
||
strip = def: if def.value._type or "" == "override" then def // { value = def.value.content; } else def;
|
||
in concatMap (def: if getPrio def == highestPrio then [(strip def)] else []) defs;
|
||
|
||
/* Sort a list of properties. The sort priority of a property is
|
||
1000 by default, but can be overriden by wrapping the property
|
||
using mkOrder. */
|
||
sortProperties = defs:
|
||
let
|
||
strip = def:
|
||
if def.value._type or "" == "order"
|
||
then def // { value = def.value.content; inherit (def.value) priority; }
|
||
else def;
|
||
defs' = map strip defs;
|
||
compare = a: b: (a.priority or 1000) < (b.priority or 1000);
|
||
in sort compare defs';
|
||
|
||
/* Hack for backward compatibility: convert options of type
|
||
optionSet to options of type submodule. FIXME: remove
|
||
eventually. */
|
||
fixupOptionType = loc: opt:
|
||
let
|
||
options = opt.options or
|
||
(throw "Option `${showOption loc'}' has type optionSet but has no option attribute, in ${showFiles opt.declarations}.");
|
||
f = tp:
|
||
if tp.name == "option set" || tp.name == "submodule" then
|
||
throw "The option ${showOption loc} uses submodules without a wrapping type, in ${showFiles opt.declarations}."
|
||
else if tp.name == "attribute set of option sets" then types.attrsOf (types.submodule options)
|
||
else if tp.name == "list or attribute set of option sets" then types.loaOf (types.submodule options)
|
||
else if tp.name == "list of option sets" then types.listOf (types.submodule options)
|
||
else if tp.name == "null or option set" then types.nullOr (types.submodule options)
|
||
else tp;
|
||
in
|
||
if opt.type.getSubModules or null == null
|
||
then opt // { type = f (opt.type or types.unspecified); }
|
||
else opt // { type = opt.type.substSubModules opt.options; options = []; };
|
||
|
||
|
||
/* Properties. */
|
||
|
||
mkIf = condition: content:
|
||
{ _type = "if";
|
||
inherit condition content;
|
||
};
|
||
|
||
mkAssert = assertion: message: content:
|
||
mkIf
|
||
(if assertion then true else throw "\nFailed assertion: ${message}")
|
||
content;
|
||
|
||
mkMerge = contents:
|
||
{ _type = "merge";
|
||
inherit contents;
|
||
};
|
||
|
||
mkOverride = priority: content:
|
||
{ _type = "override";
|
||
inherit priority content;
|
||
};
|
||
|
||
mkOptionDefault = mkOverride 1001; # priority of option defaults
|
||
mkDefault = mkOverride 1000; # used in config sections of non-user modules to set a default
|
||
mkForce = mkOverride 50;
|
||
mkVMOverride = mkOverride 10; # used by ‘nixos-rebuild build-vm’
|
||
|
||
mkStrict = builtins.trace "`mkStrict' is obsolete; use `mkOverride 0' instead." (mkOverride 0);
|
||
|
||
mkFixStrictness = id; # obsolete, no-op
|
||
|
||
mkOrder = priority: content:
|
||
{ _type = "order";
|
||
inherit priority content;
|
||
};
|
||
|
||
mkBefore = mkOrder 500;
|
||
mkAfter = mkOrder 1500;
|
||
|
||
|
||
# Convenient property used to transfer all definitions and their
|
||
# properties from one option to another. This property is useful for
|
||
# renaming options, and also for including properties from another module
|
||
# system, including sub-modules.
|
||
#
|
||
# { config, options, ... }:
|
||
#
|
||
# {
|
||
# # 'bar' might not always be defined in the current module-set.
|
||
# config.foo.enable = mkAliasDefinitions (options.bar.enable or {});
|
||
#
|
||
# # 'barbaz' has to be defined in the current module-set.
|
||
# config.foobar.paths = mkAliasDefinitions options.barbaz.paths;
|
||
# }
|
||
#
|
||
# Note, this is different than taking the value of the option and using it
|
||
# as a definition, as the new definition will not keep the mkOverride /
|
||
# mkDefault properties of the previous option.
|
||
#
|
||
mkAliasDefinitions = mkAliasAndWrapDefinitions id;
|
||
mkAliasAndWrapDefinitions = wrap: option:
|
||
mkMerge
|
||
(optional (isOption option && option.isDefined)
|
||
(wrap (mkMerge option.definitions)));
|
||
|
||
|
||
/* Compatibility. */
|
||
fixMergeModules = modules: args: evalModules { inherit modules args; check = false; };
|
||
|
||
|
||
/* Return a module that causes a warning to be shown if the
|
||
specified option is defined. For example,
|
||
|
||
mkRemovedOptionModule [ "boot" "loader" "grub" "bootDevice" ]
|
||
|
||
causes a warning if the user defines boot.loader.grub.bootDevice.
|
||
*/
|
||
mkRemovedOptionModule = optionName:
|
||
{ options, ... }:
|
||
{ options = setAttrByPath optionName (mkOption {
|
||
visible = false;
|
||
});
|
||
config.warnings =
|
||
let opt = getAttrFromPath optionName options; in
|
||
optional opt.isDefined
|
||
"The option definition `${showOption optionName}' in ${showFiles opt.files} no longer has any effect; please remove it.";
|
||
};
|
||
|
||
/* Return a module that causes a warning to be shown if the
|
||
specified "from" option is defined; the defined value is however
|
||
forwarded to the "to" option. This can be used to rename options
|
||
while providing backward compatibility. For example,
|
||
|
||
mkRenamedOptionModule [ "boot" "copyKernels" ] [ "boot" "loader" "grub" "copyKernels" ]
|
||
|
||
forwards any definitions of boot.copyKernels to
|
||
boot.loader.grub.copyKernels while printing a warning.
|
||
*/
|
||
mkRenamedOptionModule = from: to: doRename {
|
||
inherit from to;
|
||
visible = false;
|
||
warn = true;
|
||
use = builtins.trace "Obsolete option `${showOption from}' is used. It was renamed to `${showOption to}'.";
|
||
};
|
||
|
||
/* Like ‘mkRenamedOptionModule’, but doesn't show a warning. */
|
||
mkAliasOptionModule = from: to: doRename {
|
||
inherit from to;
|
||
visible = true;
|
||
warn = false;
|
||
use = id;
|
||
};
|
||
|
||
doRename = { from, to, visible, warn, use }:
|
||
let
|
||
toOf = attrByPath to
|
||
(abort "Renaming error: option `${showOption to}' does not exists.");
|
||
in
|
||
{ config, options, ... }:
|
||
{ options = setAttrByPath from (mkOption {
|
||
description = "Alias of <option>${showOption to}</option>.";
|
||
apply = x: use (toOf config);
|
||
});
|
||
config = {
|
||
warnings =
|
||
let opt = getAttrFromPath from options; in
|
||
optional (warn && opt.isDefined)
|
||
"The option `${showOption from}' defined in ${showFiles opt.files} has been renamed to `${showOption to}'.";
|
||
} // setAttrByPath to (mkAliasDefinitions (getAttrFromPath from options));
|
||
};
|
||
|
||
}
|