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nixpkgs/lib/deprecated.nix
danbst 68a6b47b8c lib: add shortcuts for fake hashes (fakeSha256, fakeSha512)
Fake hashes can be used as placeholders for all the places, where
Nix expression requires a hash, but we don't yet have one.

This should be more convenient than following:
- echo|sha256sum, copy into clipboard, go to editor, paste into previously
  edited place
- search nixpkgs for a random package, copy it's hash to cliboard, go to
  editor, paste into previously edited place

Nix can add support for these fake hashes. In that case printed error should contain
only 1 hash, so no more problem "which of two hashes from error should I use?"

Idea by irc:Synthetica
2019-01-10 19:27:35 +02:00

278 lines
10 KiB
Nix

{ lib }:
let
inherit (builtins) head tail isList isAttrs isInt attrNames;
in
with lib.lists;
with lib.attrsets;
with lib.strings;
rec {
# returns default if env var is not set
maybeEnv = name: default:
let value = builtins.getEnv name; in
if value == "" then default else value;
defaultMergeArg = x : y: if builtins.isAttrs y then
y
else
(y x);
defaultMerge = x: y: x // (defaultMergeArg x y);
foldArgs = merger: f: init: x:
let arg = (merger init (defaultMergeArg init x));
# now add the function with composed args already applied to the final attrs
base = (setAttrMerge "passthru" {} (f arg)
( z: z // rec {
function = foldArgs merger f arg;
args = (lib.attrByPath ["passthru" "args"] {} z) // x;
} ));
withStdOverrides = base // {
override = base.passthru.function;
};
in
withStdOverrides;
# shortcut for attrByPath ["name"] default attrs
maybeAttrNullable = maybeAttr;
# shortcut for attrByPath ["name"] default attrs
maybeAttr = name: default: attrs: attrs.${name} or default;
# Return the second argument if the first one is true or the empty version
# of the second argument.
ifEnable = cond: val:
if cond then val
else if builtins.isList val then []
else if builtins.isAttrs val then {}
# else if builtins.isString val then ""
else if val == true || val == false then false
else null;
# Return true only if there is an attribute and it is true.
checkFlag = attrSet: name:
if name == "true" then true else
if name == "false" then false else
if (elem name (attrByPath ["flags"] [] attrSet)) then true else
attrByPath [name] false attrSet ;
# Input : attrSet, [ [name default] ... ], name
# Output : its value or default.
getValue = attrSet: argList: name:
( attrByPath [name] (if checkFlag attrSet name then true else
if argList == [] then null else
let x = builtins.head argList; in
if (head x) == name then
(head (tail x))
else (getValue attrSet
(tail argList) name)) attrSet );
# Input : attrSet, [[name default] ...], [ [flagname reqs..] ... ]
# Output : are reqs satisfied? It's asserted.
checkReqs = attrSet: argList: condList:
(
fold lib.and true
(map (x: let name = (head x); in
((checkFlag attrSet name) ->
(fold lib.and true
(map (y: let val=(getValue attrSet argList y); in
(val!=null) && (val!=false))
(tail x))))) condList));
# This function has O(n^2) performance.
uniqList = { inputList, acc ? [] }:
let go = xs: acc:
if xs == []
then []
else let x = head xs;
y = if elem x acc then [] else [x];
in y ++ go (tail xs) (y ++ acc);
in go inputList acc;
uniqListExt = { inputList,
outputList ? [],
getter ? (x: x),
compare ? (x: y: x==y) }:
if inputList == [] then outputList else
let x = head inputList;
isX = y: (compare (getter y) (getter x));
newOutputList = outputList ++
(if any isX outputList then [] else [x]);
in uniqListExt { outputList = newOutputList;
inputList = (tail inputList);
inherit getter compare;
};
condConcat = name: list: checker:
if list == [] then name else
if checker (head list) then
condConcat
(name + (head (tail list)))
(tail (tail list))
checker
else condConcat
name (tail (tail list)) checker;
lazyGenericClosure = {startSet, operator}:
let
work = list: doneKeys: result:
if list == [] then
result
else
let x = head list; key = x.key; in
if elem key doneKeys then
work (tail list) doneKeys result
else
work (tail list ++ operator x) ([key] ++ doneKeys) ([x] ++ result);
in
work startSet [] [];
innerModifySumArgs = f: x: a: b: if b == null then (f a b) // x else
innerModifySumArgs f x (a // b);
modifySumArgs = f: x: innerModifySumArgs f x {};
innerClosePropagation = acc: xs:
if xs == []
then acc
else let y = head xs;
ys = tail xs;
in if ! isAttrs y
then innerClosePropagation acc ys
else let acc' = [y] ++ acc;
in innerClosePropagation
acc'
(uniqList { inputList = (maybeAttrNullable "propagatedBuildInputs" [] y)
++ (maybeAttrNullable "propagatedNativeBuildInputs" [] y)
++ ys;
acc = acc';
}
);
closePropagation = list: (uniqList {inputList = (innerClosePropagation [] list);});
# calls a function (f attr value ) for each record item. returns a list
mapAttrsFlatten = f: r: map (attr: f attr r.${attr}) (attrNames r);
# attribute set containing one attribute
nvs = name: value: listToAttrs [ (nameValuePair name value) ];
# adds / replaces an attribute of an attribute set
setAttr = set: name: v: set // (nvs name v);
# setAttrMerge (similar to mergeAttrsWithFunc but only merges the values of a particular name)
# setAttrMerge "a" [] { a = [2];} (x: x ++ [3]) -> { a = [2 3]; }
# setAttrMerge "a" [] { } (x: x ++ [3]) -> { a = [ 3]; }
setAttrMerge = name: default: attrs: f:
setAttr attrs name (f (maybeAttr name default attrs));
# Using f = a: b = b the result is similar to //
# merge attributes with custom function handling the case that the attribute
# exists in both sets
mergeAttrsWithFunc = f: set1: set2:
fold (n: set: if set ? ${n}
then setAttr set n (f set.${n} set2.${n})
else set )
(set2 // set1) (attrNames set2);
# merging two attribute set concatenating the values of same attribute names
# eg { a = 7; } { a = [ 2 3 ]; } becomes { a = [ 7 2 3 ]; }
mergeAttrsConcatenateValues = mergeAttrsWithFunc ( a: b: (toList a) ++ (toList b) );
# merges attributes using //, if a name exists in both attributes
# an error will be triggered unless its listed in mergeLists
# so you can mergeAttrsNoOverride { buildInputs = [a]; } { buildInputs = [a]; } {} to get
# { buildInputs = [a b]; }
# merging buildPhase doesn't really make sense. The cases will be rare where appending /prefixing will fit your needs?
# in these cases the first buildPhase will override the second one
# ! deprecated, use mergeAttrByFunc instead
mergeAttrsNoOverride = { mergeLists ? ["buildInputs" "propagatedBuildInputs"],
overrideSnd ? [ "buildPhase" ]
}: attrs1: attrs2:
fold (n: set:
setAttr set n ( if set ? ${n}
then # merge
if elem n mergeLists # attribute contains list, merge them by concatenating
then attrs2.${n} ++ attrs1.${n}
else if elem n overrideSnd
then attrs1.${n}
else throw "error mergeAttrsNoOverride, attribute ${n} given in both attributes - no merge func defined"
else attrs2.${n} # add attribute not existing in attr1
)) attrs1 (attrNames attrs2);
# example usage:
# mergeAttrByFunc {
# inherit mergeAttrBy; # defined below
# buildInputs = [ a b ];
# } {
# buildInputs = [ c d ];
# };
# will result in
# { mergeAttrsBy = [...]; buildInputs = [ a b c d ]; }
# is used by defaultOverridableDelayableArgs and can be used when composing using
# foldArgs, composedArgsAndFun or applyAndFun. Example: composableDerivation in all-packages.nix
mergeAttrByFunc = x: y:
let
mergeAttrBy2 = { mergeAttrBy = lib.mergeAttrs; }
// (maybeAttr "mergeAttrBy" {} x)
// (maybeAttr "mergeAttrBy" {} y); in
fold lib.mergeAttrs {} [
x y
(mapAttrs ( a: v: # merge special names using given functions
if x ? ${a}
then if y ? ${a}
then v x.${a} y.${a} # both have attr, use merge func
else x.${a} # only x has attr
else y.${a} # only y has attr)
) (removeAttrs mergeAttrBy2
# don't merge attrs which are neither in x nor y
(filter (a: ! x ? ${a} && ! y ? ${a})
(attrNames mergeAttrBy2))
)
)
];
mergeAttrsByFuncDefaults = foldl mergeAttrByFunc { inherit mergeAttrBy; };
mergeAttrsByFuncDefaultsClean = list: removeAttrs (mergeAttrsByFuncDefaults list) ["mergeAttrBy"];
# sane defaults (same name as attr name so that inherit can be used)
mergeAttrBy = # { buildInputs = concatList; [...]; passthru = mergeAttr; [..]; }
listToAttrs (map (n: nameValuePair n lib.concat)
[ "nativeBuildInputs" "buildInputs" "propagatedBuildInputs" "configureFlags" "prePhases" "postAll" "patches" ])
// listToAttrs (map (n: nameValuePair n lib.mergeAttrs) [ "passthru" "meta" "cfg" "flags" ])
// listToAttrs (map (n: nameValuePair n (a: b: "${a}\n${b}") ) [ "preConfigure" "postInstall" ])
;
nixType = x:
if isAttrs x then
if x ? outPath then "derivation"
else "attrs"
else if lib.isFunction x then "function"
else if isList x then "list"
else if x == true then "bool"
else if x == false then "bool"
else if x == null then "null"
else if isInt x then "int"
else "string";
/* deprecated:
For historical reasons, imap has an index starting at 1.
But for consistency with the rest of the library we want an index
starting at zero.
*/
imap = imap1;
# Fake hashes. Can be used as hash placeholders, when computing hash ahead isn't trivial
fakeSha256 = "0000000000000000000000000000000000000000000000000000000000000000";
fakeSha512 = "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000";
}