582 lines
22 KiB
Nix
582 lines
22 KiB
Nix
# Definitions related to run-time type checking. Used in particular
|
||
# to type-check NixOS configurations.
|
||
{ lib }:
|
||
with lib.lists;
|
||
with lib.attrsets;
|
||
with lib.options;
|
||
with lib.trivial;
|
||
with lib.strings;
|
||
let
|
||
|
||
inherit (lib.modules) mergeDefinitions;
|
||
outer_types =
|
||
rec {
|
||
isType = type: x: (x._type or "") == type;
|
||
|
||
setType = typeName: value: value // {
|
||
_type = typeName;
|
||
};
|
||
|
||
|
||
# Default type merging function
|
||
# takes two type functors and return the merged type
|
||
defaultTypeMerge = f: f':
|
||
let wrapped = f.wrapped.typeMerge f'.wrapped.functor;
|
||
payload = f.binOp f.payload f'.payload;
|
||
in
|
||
# cannot merge different types
|
||
if f.name != f'.name
|
||
then null
|
||
# simple types
|
||
else if (f.wrapped == null && f'.wrapped == null)
|
||
&& (f.payload == null && f'.payload == null)
|
||
then f.type
|
||
# composed types
|
||
else if (f.wrapped != null && f'.wrapped != null) && (wrapped != null)
|
||
then f.type wrapped
|
||
# value types
|
||
else if (f.payload != null && f'.payload != null) && (payload != null)
|
||
then f.type payload
|
||
else null;
|
||
|
||
# Default type functor
|
||
defaultFunctor = name: {
|
||
inherit name;
|
||
type = types.${name} or null;
|
||
wrapped = null;
|
||
payload = null;
|
||
binOp = a: b: null;
|
||
};
|
||
|
||
isOptionType = isType "option-type";
|
||
mkOptionType =
|
||
{ # Human-readable representation of the type, should be equivalent to
|
||
# the type function name.
|
||
name
|
||
, # Description of the type, defined recursively by embedding the wrapped type if any.
|
||
description ? null
|
||
, # Function applied to each definition that should return true if
|
||
# its type-correct, false otherwise.
|
||
check ? (x: true)
|
||
, # Merge a list of definitions together into a single value.
|
||
# This function is called with two arguments: the location of
|
||
# the option in the configuration as a list of strings
|
||
# (e.g. ["boot" "loader "grub" "enable"]), and a list of
|
||
# definition values and locations (e.g. [ { file = "/foo.nix";
|
||
# value = 1; } { file = "/bar.nix"; value = 2 } ]).
|
||
merge ? mergeDefaultOption
|
||
, # Whether this type has a value representing nothingness. If it does,
|
||
# this should be a value of the form { value = <the nothing value>; }
|
||
# If it doesn't, this should be {}
|
||
# This may be used when a value is required for `mkIf false`. This allows the extra laziness in e.g. `lazyAttrsOf`.
|
||
emptyValue ? {}
|
||
, # Return a flat list of sub-options. Used to generate
|
||
# documentation.
|
||
getSubOptions ? prefix: {}
|
||
, # List of modules if any, or null if none.
|
||
getSubModules ? null
|
||
, # Function for building the same option type with a different list of
|
||
# modules.
|
||
substSubModules ? m: null
|
||
, # Function that merge type declarations.
|
||
# internal, takes a functor as argument and returns the merged type.
|
||
# returning null means the type is not mergeable
|
||
typeMerge ? defaultTypeMerge functor
|
||
, # The type functor.
|
||
# internal, representation of the type as an attribute set.
|
||
# name: name of the type
|
||
# type: type function.
|
||
# wrapped: the type wrapped in case of compound types.
|
||
# payload: values of the type, two payloads of the same type must be
|
||
# combinable with the binOp binary operation.
|
||
# binOp: binary operation that merge two payloads of the same type.
|
||
functor ? defaultFunctor name
|
||
, # The deprecation message to display when this type is used by an option
|
||
# If null, the type isn't deprecated
|
||
deprecationMessage ? null
|
||
}:
|
||
{ _type = "option-type";
|
||
inherit name check merge emptyValue getSubOptions getSubModules substSubModules typeMerge functor deprecationMessage;
|
||
description = if description == null then name else description;
|
||
};
|
||
|
||
|
||
# When adding new types don't forget to document them in
|
||
# nixos/doc/manual/development/option-types.xml!
|
||
types = rec {
|
||
|
||
anything = mkOptionType {
|
||
name = "anything";
|
||
description = "anything";
|
||
check = value: true;
|
||
merge = loc: defs:
|
||
let
|
||
getType = value:
|
||
if isAttrs value && isCoercibleToString value
|
||
then "stringCoercibleSet"
|
||
else builtins.typeOf value;
|
||
|
||
# Returns the common type of all definitions, throws an error if they
|
||
# don't have the same type
|
||
commonType = foldl' (type: def:
|
||
if getType def.value == type
|
||
then type
|
||
else throw "The option `${showOption loc}' has conflicting option types in ${showFiles (getFiles defs)}"
|
||
) (getType (head defs).value) defs;
|
||
|
||
mergeFunction = {
|
||
# Recursively merge attribute sets
|
||
set = (attrsOf anything).merge;
|
||
# Safe and deterministic behavior for lists is to only accept one definition
|
||
# listOf only used to apply mkIf and co.
|
||
list =
|
||
if length defs > 1
|
||
then throw "The option `${showOption loc}' has conflicting definitions, in ${showFiles (getFiles defs)}."
|
||
else (listOf anything).merge;
|
||
# This is the type of packages, only accept a single definition
|
||
stringCoercibleSet = mergeOneOption;
|
||
# Otherwise fall back to only allowing all equal definitions
|
||
}.${commonType} or mergeEqualOption;
|
||
in mergeFunction loc defs;
|
||
};
|
||
|
||
unspecified = mkOptionType {
|
||
name = "unspecified";
|
||
};
|
||
|
||
bool = mkOptionType {
|
||
name = "bool";
|
||
description = "boolean";
|
||
check = isBool;
|
||
merge = mergeEqualOption;
|
||
};
|
||
|
||
int = mkOptionType {
|
||
name = "int";
|
||
description = "signed integer";
|
||
check = isInt;
|
||
merge = mergeEqualOption;
|
||
};
|
||
|
||
# Specialized subdomains of int
|
||
ints =
|
||
let
|
||
betweenDesc = lowest: highest:
|
||
"${toString lowest} and ${toString highest} (both inclusive)";
|
||
between = lowest: highest:
|
||
assert lib.assertMsg (lowest <= highest)
|
||
"ints.between: lowest must be smaller than highest";
|
||
addCheck int (x: x >= lowest && x <= highest) // {
|
||
name = "intBetween";
|
||
description = "integer between ${betweenDesc lowest highest}";
|
||
};
|
||
ign = lowest: highest: name: docStart:
|
||
between lowest highest // {
|
||
inherit name;
|
||
description = docStart + "; between ${betweenDesc lowest highest}";
|
||
};
|
||
unsign = bit: range: ign 0 (range - 1)
|
||
"unsignedInt${toString bit}" "${toString bit} bit unsigned integer";
|
||
sign = bit: range: ign (0 - (range / 2)) (range / 2 - 1)
|
||
"signedInt${toString bit}" "${toString bit} bit signed integer";
|
||
|
||
in {
|
||
/* An int with a fixed range.
|
||
*
|
||
* Example:
|
||
* (ints.between 0 100).check (-1)
|
||
* => false
|
||
* (ints.between 0 100).check (101)
|
||
* => false
|
||
* (ints.between 0 0).check 0
|
||
* => true
|
||
*/
|
||
inherit between;
|
||
|
||
unsigned = addCheck types.int (x: x >= 0) // {
|
||
name = "unsignedInt";
|
||
description = "unsigned integer, meaning >=0";
|
||
};
|
||
positive = addCheck types.int (x: x > 0) // {
|
||
name = "positiveInt";
|
||
description = "positive integer, meaning >0";
|
||
};
|
||
u8 = unsign 8 256;
|
||
u16 = unsign 16 65536;
|
||
# the biggest int a 64-bit Nix accepts is 2^63 - 1 (9223372036854775808), for a 32-bit Nix it is 2^31 - 1 (2147483647)
|
||
# the smallest int a 64-bit Nix accepts is -2^63 (-9223372036854775807), for a 32-bit Nix it is -2^31 (-2147483648)
|
||
# u32 = unsign 32 4294967296;
|
||
# u64 = unsign 64 18446744073709551616;
|
||
|
||
s8 = sign 8 256;
|
||
s16 = sign 16 65536;
|
||
# s32 = sign 32 4294967296;
|
||
};
|
||
|
||
# Alias of u16 for a port number
|
||
port = ints.u16;
|
||
|
||
float = mkOptionType {
|
||
name = "float";
|
||
description = "floating point number";
|
||
check = isFloat;
|
||
merge = mergeEqualOption;
|
||
};
|
||
|
||
str = mkOptionType {
|
||
name = "str";
|
||
description = "string";
|
||
check = isString;
|
||
merge = mergeEqualOption;
|
||
};
|
||
|
||
strMatching = pattern: mkOptionType {
|
||
name = "strMatching ${escapeNixString pattern}";
|
||
description = "string matching the pattern ${pattern}";
|
||
check = x: str.check x && builtins.match pattern x != null;
|
||
inherit (str) merge;
|
||
};
|
||
|
||
# Merge multiple definitions by concatenating them (with the given
|
||
# separator between the values).
|
||
separatedString = sep: mkOptionType rec {
|
||
name = "separatedString";
|
||
description = if sep == ""
|
||
then "Concatenated string" # for types.string.
|
||
else "strings concatenated with ${builtins.toJSON sep}"
|
||
;
|
||
check = isString;
|
||
merge = loc: defs: concatStringsSep sep (getValues defs);
|
||
functor = (defaultFunctor name) // {
|
||
payload = sep;
|
||
binOp = sepLhs: sepRhs:
|
||
if sepLhs == sepRhs then sepLhs
|
||
else null;
|
||
};
|
||
};
|
||
|
||
lines = separatedString "\n";
|
||
commas = separatedString ",";
|
||
envVar = separatedString ":";
|
||
|
||
# Deprecated; should not be used because it quietly concatenates
|
||
# strings, which is usually not what you want.
|
||
string = separatedString "" // {
|
||
name = "string";
|
||
deprecationMessage = "See https://github.com/NixOS/nixpkgs/pull/66346 for better alternative types.";
|
||
};
|
||
|
||
attrs = mkOptionType {
|
||
name = "attrs";
|
||
description = "attribute set";
|
||
check = isAttrs;
|
||
merge = loc: foldl' (res: def: mergeAttrs res def.value) {};
|
||
emptyValue = { value = {}; };
|
||
};
|
||
|
||
# derivation is a reserved keyword.
|
||
package = mkOptionType {
|
||
name = "package";
|
||
check = x: isDerivation x || isStorePath x;
|
||
merge = loc: defs:
|
||
let res = mergeOneOption loc defs;
|
||
in if isDerivation res then res else toDerivation res;
|
||
};
|
||
|
||
shellPackage = package // {
|
||
check = x: (package.check x) && (hasAttr "shellPath" x);
|
||
};
|
||
|
||
path = mkOptionType {
|
||
name = "path";
|
||
check = x: isCoercibleToString x && builtins.substring 0 1 (toString x) == "/";
|
||
merge = mergeEqualOption;
|
||
};
|
||
|
||
listOf = elemType: mkOptionType rec {
|
||
name = "listOf";
|
||
description = "list of ${elemType.description}s";
|
||
check = isList;
|
||
merge = loc: defs:
|
||
map (x: x.value) (filter (x: x ? value) (concatLists (imap1 (n: def:
|
||
imap1 (m: def':
|
||
(mergeDefinitions
|
||
(loc ++ ["[definition ${toString n}-entry ${toString m}]"])
|
||
elemType
|
||
[{ inherit (def) file; value = def'; }]
|
||
).optionalValue
|
||
) def.value
|
||
) defs)));
|
||
emptyValue = { value = {}; };
|
||
getSubOptions = prefix: elemType.getSubOptions (prefix ++ ["*"]);
|
||
getSubModules = elemType.getSubModules;
|
||
substSubModules = m: listOf (elemType.substSubModules m);
|
||
functor = (defaultFunctor name) // { wrapped = elemType; };
|
||
};
|
||
|
||
nonEmptyListOf = elemType:
|
||
let list = addCheck (types.listOf elemType) (l: l != []);
|
||
in list // {
|
||
description = "non-empty " + list.description;
|
||
# Note: emptyValue is left as is, because another module may define an element.
|
||
};
|
||
|
||
attrsOf = elemType: mkOptionType rec {
|
||
name = "attrsOf";
|
||
description = "attribute set of ${elemType.description}s";
|
||
check = isAttrs;
|
||
merge = loc: defs:
|
||
mapAttrs (n: v: v.value) (filterAttrs (n: v: v ? value) (zipAttrsWith (name: defs:
|
||
(mergeDefinitions (loc ++ [name]) elemType defs).optionalValue
|
||
)
|
||
# Push down position info.
|
||
(map (def: mapAttrs (n: v: { inherit (def) file; value = v; }) def.value) defs)));
|
||
emptyValue = { value = {}; };
|
||
getSubOptions = prefix: elemType.getSubOptions (prefix ++ ["<name>"]);
|
||
getSubModules = elemType.getSubModules;
|
||
substSubModules = m: attrsOf (elemType.substSubModules m);
|
||
functor = (defaultFunctor name) // { wrapped = elemType; };
|
||
};
|
||
|
||
# A version of attrsOf that's lazy in its values at the expense of
|
||
# conditional definitions not working properly. E.g. defining a value with
|
||
# `foo.attr = mkIf false 10`, then `foo ? attr == true`, whereas with
|
||
# attrsOf it would correctly be `false`. Accessing `foo.attr` would throw an
|
||
# error that it's not defined. Use only if conditional definitions don't make sense.
|
||
lazyAttrsOf = elemType: mkOptionType rec {
|
||
name = "lazyAttrsOf";
|
||
description = "lazy attribute set of ${elemType.description}s";
|
||
check = isAttrs;
|
||
merge = loc: defs:
|
||
zipAttrsWith (name: defs:
|
||
let merged = mergeDefinitions (loc ++ [name]) elemType defs;
|
||
# mergedValue will trigger an appropriate error when accessed
|
||
in merged.optionalValue.value or elemType.emptyValue.value or merged.mergedValue
|
||
)
|
||
# Push down position info.
|
||
(map (def: mapAttrs (n: v: { inherit (def) file; value = v; }) def.value) defs);
|
||
emptyValue = { value = {}; };
|
||
getSubOptions = prefix: elemType.getSubOptions (prefix ++ ["<name>"]);
|
||
getSubModules = elemType.getSubModules;
|
||
substSubModules = m: lazyAttrsOf (elemType.substSubModules m);
|
||
functor = (defaultFunctor name) // { wrapped = elemType; };
|
||
};
|
||
|
||
# TODO: drop this in the future:
|
||
loaOf = elemType: types.attrsOf elemType // {
|
||
name = "loaOf";
|
||
deprecationMessage = "Mixing lists with attribute values is no longer"
|
||
+ " possible; please use `types.attrsOf` instead. See"
|
||
+ " https://github.com/NixOS/nixpkgs/issues/1800 for the motivation.";
|
||
};
|
||
|
||
# Value of given type but with no merging (i.e. `uniq list`s are not concatenated).
|
||
uniq = elemType: mkOptionType rec {
|
||
name = "uniq";
|
||
inherit (elemType) description check;
|
||
merge = mergeOneOption;
|
||
emptyValue = elemType.emptyValue;
|
||
getSubOptions = elemType.getSubOptions;
|
||
getSubModules = elemType.getSubModules;
|
||
substSubModules = m: uniq (elemType.substSubModules m);
|
||
functor = (defaultFunctor name) // { wrapped = elemType; };
|
||
};
|
||
|
||
# Null or value of ...
|
||
nullOr = elemType: mkOptionType rec {
|
||
name = "nullOr";
|
||
description = "null or ${elemType.description}";
|
||
check = x: x == null || elemType.check x;
|
||
merge = loc: defs:
|
||
let nrNulls = count (def: def.value == null) defs; in
|
||
if nrNulls == length defs then null
|
||
else if nrNulls != 0 then
|
||
throw "The option `${showOption loc}` is defined both null and not null, in ${showFiles (getFiles defs)}."
|
||
else elemType.merge loc defs;
|
||
emptyValue = { value = null; };
|
||
getSubOptions = elemType.getSubOptions;
|
||
getSubModules = elemType.getSubModules;
|
||
substSubModules = m: nullOr (elemType.substSubModules m);
|
||
functor = (defaultFunctor name) // { wrapped = elemType; };
|
||
};
|
||
|
||
# A submodule (like typed attribute set). See NixOS manual.
|
||
submodule = modules: submoduleWith {
|
||
shorthandOnlyDefinesConfig = true;
|
||
modules = toList modules;
|
||
};
|
||
|
||
submoduleWith =
|
||
{ modules
|
||
, specialArgs ? {}
|
||
, shorthandOnlyDefinesConfig ? false
|
||
}@attrs:
|
||
let
|
||
inherit (lib.modules) evalModules;
|
||
|
||
coerce = unify: value: if isFunction value
|
||
then setFunctionArgs (args: unify (value args)) (functionArgs value)
|
||
else unify (if shorthandOnlyDefinesConfig then { config = value; } else value);
|
||
|
||
allModules = defs: modules ++ imap1 (n: { value, file }:
|
||
if isAttrs value || isFunction value then
|
||
# Annotate the value with the location of its definition for better error messages
|
||
coerce (lib.modules.unifyModuleSyntax file "${toString file}-${toString n}") value
|
||
else value
|
||
) defs;
|
||
|
||
freeformType = (evalModules {
|
||
inherit modules specialArgs;
|
||
args.name = "‹name›";
|
||
})._module.freeformType;
|
||
|
||
in
|
||
mkOptionType rec {
|
||
name = "submodule";
|
||
description = freeformType.description or name;
|
||
check = x: isAttrs x || isFunction x || path.check x;
|
||
merge = loc: defs:
|
||
(evalModules {
|
||
modules = allModules defs;
|
||
inherit specialArgs;
|
||
args.name = last loc;
|
||
prefix = loc;
|
||
}).config;
|
||
emptyValue = { value = {}; };
|
||
getSubOptions = prefix: (evalModules
|
||
{ inherit modules prefix specialArgs;
|
||
# This is a work-around due to the fact that some sub-modules,
|
||
# such as the one included in an attribute set, expects a "args"
|
||
# attribute to be given to the sub-module. As the option
|
||
# evaluation does not have any specific attribute name, we
|
||
# provide a default one for the documentation.
|
||
#
|
||
# This is mandatory as some option declaration might use the
|
||
# "name" attribute given as argument of the submodule and use it
|
||
# as the default of option declarations.
|
||
#
|
||
# Using lookalike unicode single angle quotation marks because
|
||
# of the docbook transformation the options receive. In all uses
|
||
# > and < wouldn't be encoded correctly so the encoded values
|
||
# would be used, and use of `<` and `>` would break the XML document.
|
||
# It shouldn't cause an issue since this is cosmetic for the manual.
|
||
args.name = "‹name›";
|
||
}).options // optionalAttrs (freeformType != null) {
|
||
# Expose the sub options of the freeform type. Note that the option
|
||
# discovery doesn't care about the attribute name used here, so this
|
||
# is just to avoid conflicts with potential options from the submodule
|
||
_freeformOptions = freeformType.getSubOptions prefix;
|
||
};
|
||
getSubModules = modules;
|
||
substSubModules = m: submoduleWith (attrs // {
|
||
modules = m;
|
||
});
|
||
functor = defaultFunctor name // {
|
||
type = types.submoduleWith;
|
||
payload = {
|
||
modules = modules;
|
||
specialArgs = specialArgs;
|
||
shorthandOnlyDefinesConfig = shorthandOnlyDefinesConfig;
|
||
};
|
||
binOp = lhs: rhs: {
|
||
modules = lhs.modules ++ rhs.modules;
|
||
specialArgs =
|
||
let intersecting = builtins.intersectAttrs lhs.specialArgs rhs.specialArgs;
|
||
in if intersecting == {}
|
||
then lhs.specialArgs // rhs.specialArgs
|
||
else throw "A submoduleWith option is declared multiple times with the same specialArgs \"${toString (attrNames intersecting)}\"";
|
||
shorthandOnlyDefinesConfig =
|
||
if lhs.shorthandOnlyDefinesConfig == rhs.shorthandOnlyDefinesConfig
|
||
then lhs.shorthandOnlyDefinesConfig
|
||
else throw "A submoduleWith option is declared multiple times with conflicting shorthandOnlyDefinesConfig values";
|
||
};
|
||
};
|
||
};
|
||
|
||
# A value from a set of allowed ones.
|
||
enum = values:
|
||
let
|
||
show = v:
|
||
if builtins.isString v then ''"${v}"''
|
||
else if builtins.isInt v then builtins.toString v
|
||
else if builtins.isBool v then boolToString v
|
||
else ''<${builtins.typeOf v}>'';
|
||
in
|
||
mkOptionType rec {
|
||
name = "enum";
|
||
description = "one of ${concatMapStringsSep ", " show values}";
|
||
check = flip elem values;
|
||
merge = mergeEqualOption;
|
||
functor = (defaultFunctor name) // { payload = values; binOp = a: b: unique (a ++ b); };
|
||
};
|
||
|
||
# Either value of type `t1` or `t2`.
|
||
either = t1: t2: mkOptionType rec {
|
||
name = "either";
|
||
description = "${t1.description} or ${t2.description}";
|
||
check = x: t1.check x || t2.check x;
|
||
merge = loc: defs:
|
||
let
|
||
defList = map (d: d.value) defs;
|
||
in
|
||
if all (x: t1.check x) defList
|
||
then t1.merge loc defs
|
||
else if all (x: t2.check x) defList
|
||
then t2.merge loc defs
|
||
else mergeOneOption loc defs;
|
||
typeMerge = f':
|
||
let mt1 = t1.typeMerge (elemAt f'.wrapped 0).functor;
|
||
mt2 = t2.typeMerge (elemAt f'.wrapped 1).functor;
|
||
in
|
||
if (name == f'.name) && (mt1 != null) && (mt2 != null)
|
||
then functor.type mt1 mt2
|
||
else null;
|
||
functor = (defaultFunctor name) // { wrapped = [ t1 t2 ]; };
|
||
};
|
||
|
||
# Any of the types in the given list
|
||
oneOf = ts:
|
||
let
|
||
head' = if ts == [] then throw "types.oneOf needs to get at least one type in its argument" else head ts;
|
||
tail' = tail ts;
|
||
in foldl' either head' tail';
|
||
|
||
# Either value of type `coercedType` or `finalType`, the former is
|
||
# converted to `finalType` using `coerceFunc`.
|
||
coercedTo = coercedType: coerceFunc: finalType:
|
||
assert lib.assertMsg (coercedType.getSubModules == null)
|
||
"coercedTo: coercedType must not have submodules (it’s a ${
|
||
coercedType.description})";
|
||
mkOptionType rec {
|
||
name = "coercedTo";
|
||
description = "${finalType.description} or ${coercedType.description} convertible to it";
|
||
check = x: (coercedType.check x && finalType.check (coerceFunc x)) || finalType.check x;
|
||
merge = loc: defs:
|
||
let
|
||
coerceVal = val:
|
||
if coercedType.check val then coerceFunc val
|
||
else val;
|
||
in finalType.merge loc (map (def: def // { value = coerceVal def.value; }) defs);
|
||
emptyValue = finalType.emptyValue;
|
||
getSubOptions = finalType.getSubOptions;
|
||
getSubModules = finalType.getSubModules;
|
||
substSubModules = m: coercedTo coercedType coerceFunc (finalType.substSubModules m);
|
||
typeMerge = t1: t2: null;
|
||
functor = (defaultFunctor name) // { wrapped = finalType; };
|
||
};
|
||
|
||
# Obsolete alternative to configOf. It takes its option
|
||
# declarations from the ‘options’ attribute of containing option
|
||
# declaration.
|
||
optionSet = mkOptionType {
|
||
name = "optionSet";
|
||
description = "option set";
|
||
deprecationMessage = "Use `types.submodule' instead";
|
||
};
|
||
# Augment the given type with an additional type check function.
|
||
addCheck = elemType: check: elemType // { check = x: elemType.check x && check x; };
|
||
|
||
};
|
||
};
|
||
|
||
in outer_types // outer_types.types
|