Commit graph

497 commits

Author SHA1 Message Date
Eelco Dolstra 1672bcd230
Move evaluator-specific settings out of libstore 2018-05-30 13:29:50 +02:00
Will Dietz 93ae90de0f eval.cc: add message to static_assert, message can be omitted w/c++17 2018-05-26 14:04:41 -05:00
Eelco Dolstra 4bb8741b98
Make Env self-describing
If the Env denotes a 'with', then values[0] may be an Expr* cast to a
Value*. For code that generically traverses Values/Envs, it's useful
to know this.
2018-05-22 16:02:32 +02:00
Eelco Dolstra 9fd7cf98db
Memoise checkSourcePath()
This prevents hydra-eval-jobs from statting the same files over and
over again.
2018-05-22 13:02:14 +02:00
Eelco Dolstra a91c4ca01f
In restricted eval mode, allow access to the closure of store paths
E.g. this makes

  nix eval --restrict-eval -I /nix/store/foo '(builtins.readFile "/nix/store/foo/symlink/bla")'

(where /nix/store/foo/symlink is a symlink to another path in the
closure of /nix/store/foo) succeed.

This fixes a regression in Hydra compared to Nix 1.x (where there were
no restrictions at all on access to the Nix store).
2018-05-09 15:45:05 +02:00
Eelco Dolstra 53ec5ac69f
Fix some random -Wconversion warnings 2018-05-02 13:56:34 +02:00
Tuomas Tynkkynen af86132e1a libexpr: Make unsafeGetAttrPos not crash on noPos
Currently e.g. `builtins.unsafeGetAttrPos "abort" builtins` will
eventually segfault because pos->file is an unset Symbol.

Found by afl-fuzz.
2018-04-03 15:54:42 +03:00
Shea Levy e2088febf3
concatLists: Don't pass NULL pointers to memcpy.
This is UB, even if the size is 0. See #1976.

Fixes #1976.
2018-03-14 23:44:02 -04:00
Shea Levy 14ca85688c
Actually fix nixDataDir in non-canonical path 2018-02-28 06:19:40 -05:00
Eelco Dolstra 179b896acb
Merge branch 'data-dir-non-canon' of https://github.com/shlevy/nix 2018-02-22 14:20:43 +01:00
Shea Levy ddbcd01c83
Fix restricted mode when installing in non-canonical data dir 2018-02-22 07:18:14 -05:00
Tuomas Tynkkynen 7e0360504d libexpr: Optimize prim_derivationStrict by using more symbol comparisons 2018-02-17 16:54:21 +02:00
Tuomas Tynkkynen 0845cdf944 libexpr: Rely on Boehm returning zeroed memory in EvalState::allocEnv()
Boehm guarantees that memory returned by GC_malloc() is zeroed, so take
advantage of that.
2018-02-17 16:54:21 +02:00
Eelco Dolstra 7828dca9e8
Merge branch 'register-constant' of https://github.com/shlevy/nix 2018-02-13 12:24:48 +01:00
Frederik Rietdijk 60eca58533 Nix stats: flatten statistics
Flattens the list of statistics as suggested in
https://github.com/NixOS/ofborg/issues/67. This makes it easier to work
with.
2018-02-11 14:37:50 +01:00
Shea Levy 081f14a169
Allow using RegisterPrimop to define constants.
This enables plugins to add new constants, as well as new primops.
2018-02-08 14:35:50 -05:00
Eelco Dolstra abe6be578b
Merge pull request #1816 from shlevy/add-path
Add path primop.
2018-02-07 13:32:35 +01:00
Shea Levy 69d82e5c58
Add path primop.
builtins.path allows specifying the name of a path (which makes paths
with store-illegal names now addable), allows adding paths with flat
instead of recursive hashes, allows specifying a filter (so is a
generalization of filterSource), and allows specifying an expected
hash (enabling safe path adding in pure mode).
2018-02-06 16:48:08 -05:00
Eelco Dolstra f24e726ba5
checkURI(): Check file URIs against allowedPaths
This makes e.g. 'fetchGit ./.' work (assuming that ./. is an allowed
path).
2018-02-06 14:35:33 +01:00
Eelco Dolstra 89a2a11d9f
Don't use [[noreturn]] 2018-01-19 15:00:38 +01:00
Eelco Dolstra d4dcffd643
Add pure evaluation mode
In this mode, the following restrictions apply:

* The builtins currentTime, currentSystem and storePath throw an
  error.

* $NIX_PATH and -I are ignored.

* fetchGit and fetchMercurial require a revision hash.

* fetchurl and fetchTarball require a sha256 attribute.

* No file system access is allowed outside of the paths returned by
  fetch{Git,Mercurial,url,Tarball}. Thus 'nix build -f ./foo.nix' is
  not allowed.

Thus, the evaluation result is completely reproducible from the
command line arguments. E.g.

  nix build --pure-eval '(
    let
      nix = fetchGit { url = https://github.com/NixOS/nixpkgs.git; rev = "9c927de4b179a6dd210dd88d34bda8af4b575680"; };
      nixpkgs = fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-17.09"; rev = "66b4de79e3841530e6d9c6baf98702aa1f7124e4"; };
    in (import (nix + "/release.nix") { inherit nix nixpkgs; }).build.x86_64-linux
  )'

The goal is to enable completely reproducible and traceable
evaluation. For example, a NixOS configuration could be fully
described by a single Git commit hash. 'nixos-rebuild' would do
something like

  nix build --pure-eval '(
    (import (fetchGit { url = file:///my-nixos-config; rev = "..."; })).system
  ')

where the Git repository /my-nixos-config would use further fetchGit
calls or Git externals to fetch Nixpkgs and whatever other
dependencies it has. Either way, the commit hash would uniquely
identify the NixOS configuration and allow it to reproduced.
2018-01-16 19:23:18 +01:00
Eelco Dolstra 74f75c8558
import, builtins.readFile: Handle diverted stores
Fixes #1791
2018-01-12 17:31:08 +01:00
Eelco Dolstra 812e027e1d
Add option allowed-uris
This allows network access in restricted eval mode.
2017-10-30 12:41:49 +01:00
Eelco Dolstra c1ae18941a
nix repl :t: Indicate strings that have a context 2017-10-29 17:11:22 +01:00
Jörg Thalheim 2fd8f8bb99 Replace Unicode quotes in user-facing strings by ASCII
Relevant RFC: NixOS/rfcs#4

$ ag -l | xargs sed -i -e "/\"/s/’/'/g;/\"/s/‘/'/g"
2017-07-30 12:32:45 +01:00
Eelco Dolstra fcca702a96
Replace a few bool flags with enums
Functions like copyClosure() had 3 bool arguments, which creates a
severe risk of mixing up arguments.

Also, implement copyClosure() using copyPaths().
2017-07-03 11:38:08 +02:00
Eelco Dolstra b01d62285c
Improve progress indicator 2017-05-16 16:09:57 +02:00
Eelco Dolstra f8a2e8a552
Shut up some warnings 2017-04-14 14:42:20 +02:00
Dan Peebles e7cb2847ab Explicitly model all settings and fail on unrecognized ones
Previously, the Settings class allowed other code to query for string
properties, which led to a proliferation of code all over the place making
up new options without any sort of central registry of valid options. This
commit pulls all those options back into the central Settings class and
removes the public get() methods, to discourage future abuses like that.

Furthermore, because we know the full set of options ahead of time, we
now fail loudly if someone enters an unrecognized option, thus preventing
subtle typos. With some template fun, we could probably also dump the full
set of options (with documentation, defaults, etc.) to the command line,
but I'm not doing that yet here.
2017-02-22 20:19:25 -05:00
Eelco Dolstra 6de33a9c67
Add support for passing structured data to builders
Previously, all derivation attributes had to be coerced into strings
so that they could be passed via the environment. This is lossy
(e.g. lists get flattened, necessitating configureFlags
vs. configureFlagsArray, of which the latter cannot be specified as an
attribute), doesn't support attribute sets at all, and has size
limitations (necessitating hacks like passAsFile).

This patch adds a new mode for passing attributes to builders, namely
encoded as a JSON file ".attrs.json" in the current directory of the
builder. This mode is activated via the special attribute

  __structuredAttrs = true;

(The idea is that one day we can set this in stdenv.mkDerivation.)

For example,

  stdenv.mkDerivation {
    __structuredAttrs = true;
    name = "foo";
    buildInputs = [ pkgs.hello pkgs.cowsay ];
    doCheck = true;
    hardening.format = false;
  }

results in a ".attrs.json" file containing (sans the indentation):

  {
    "buildInputs": [],
    "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash",
    "configureFlags": [
      "--with-foo",
      "--with-bar=1 2"
    ],
    "doCheck": true,
    "hardening": {
      "format": false
    },
    "name": "foo",
    "nativeBuildInputs": [
      "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10",
      "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03"
    ],
    "propagatedBuildInputs": [],
    "propagatedNativeBuildInputs": [],
    "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv",
    "system": "x86_64-linux"
  }

"passAsFile" is ignored in this mode because it's not needed - large
strings are included directly in the JSON representation.

It is up to the builder to do something with the JSON
representation. For example, in bash-based builders, lists/attrsets of
string values could be mapped to bash (associative) arrays.
2017-01-26 20:40:33 +01:00
Eelco Dolstra 54801ed6ad
Bindings: Add a method for iterating in lexicographically sorted order 2017-01-26 20:40:33 +01:00
Eelco Dolstra 215b70f51e
Revert "Get rid of unicode quotes (#1140)"
This reverts commit f78126bfd6. There
really is no need for such a massive change...
2016-11-26 00:38:01 +01:00
Guillaume Maudoux f78126bfd6 Get rid of unicode quotes (#1140) 2016-11-25 15:48:27 +01:00
Eelco Dolstra c42d1acfeb forceBool(): Show position info 2016-08-29 19:37:19 +02:00
Eelco Dolstra 26d92017d3 Add builtin function "partition"
The implementation of "partition" in Nixpkgs is O(n^2) (because of the
use of ++), and for some reason was causing stack overflows in
multi-threaded evaluation (not sure why).

This reduces "nix-env -qa --drv-path" runtime by 0.197s and memory
usage by 298 MiB (in non-Boehm mode).
2016-08-29 19:36:54 +02:00
Shea Levy 9fa21765e7 callFunction: Copy functors to the heap
Normally it's impossible to take a reference to the function passed to
callFunction, so some callers (e.g. ExprApp::eval) allocate that value
on the stack. For functors, a reference to the functor itself may be
kept, so we need to have it on the heap.

Fixes #1045
2016-08-29 07:36:28 -04:00
Eelco Dolstra d74236d1f2 nix build: Use Nix search path
That is, unless --file is specified, the Nix search path is
synthesized into an attribute set. Thus you can say

  $ nix build nixpkgs.hello

assuming $NIX_PATH contains an entry of the form "nixpkgs=...". This
is more verbose than

  $ nix build hello

but is less ambiguous.
2016-08-23 17:11:19 +02:00
Eelco Dolstra 7850d3d279 Make the store directory a member variable of Store 2016-06-01 16:24:17 +02:00
Eelco Dolstra 41633f9f73 Improved logging abstraction
This also gets rid of --log-type, since the nested log type isn't
useful in a multi-threaded situation, and nobody cares about the
"pretty" log type.
2016-04-25 19:18:45 +02:00
Eelco Dolstra 5169a6da98 Make $NIX_PATH parsing more robust 2016-04-14 17:29:08 +02:00
Eelco Dolstra 363f37d084 Make the search path lazier with non-fatal errors
Thus, -I / $NIX_PATH entries are now downloaded only when they are
needed for evaluation. An error to download an entry is a non-fatal
warning (just like non-existant paths).

This does change the semantics of builtins.nixPath, which now returns
the original, rather than resulting path. E.g., before we had

  [ { path = "/nix/store/hgm3yxf1lrrwa3z14zpqaj5p9vs0qklk-nixexprs.tar.xz"; prefix = "nixpkgs"; } ... ]

but now

  [ { path = "https://nixos.org/channels/nixos-16.03/nixexprs.tar.xz"; prefix = "nixpkgs"; } ... ]

Fixes #792.
2016-04-14 15:32:24 +02:00
Eelco Dolstra b3e8d72770 Merge pull request #762 from ctheune/ctheune-floats
Implement floats
2016-02-12 12:49:59 +01:00
Eelco Dolstra fa7cd5369b StoreAPI -> Store
Calling a class an API is a bit redundant...
2016-02-04 14:48:42 +01:00
Eelco Dolstra c10c61449f Eliminate the "store" global variable
Also, move a few free-standing functions into StoreAPI and Derivation.

Also, introduce a non-nullable smart pointer, ref<T>, which is just a
wrapper around std::shared_ptr ensuring that the pointer is never
null. (For reference-counted values, this is better than passing a
"T&", because the latter doesn't maintain the refcount. Usually, the
caller will have a shared_ptr keeping the value alive, but that's not
always the case, e.g., when passing a reference to a std::thread via
std::bind.)
2016-02-04 14:28:26 +01:00
Shea Levy 14080f3e4b Use __toString when coercing sets to strings.
For example, "${{ foo = "bar"; __toString = x: x.foo; }}" evaluates
to "bar".

With this, we can delay calling functions like mkDerivation,
buildPythonPackage, etc. until we actually need a derivation, enabling
overrides and other modifications to happen by simple attribute set
update.
2016-01-05 13:55:06 +01:00
Christian Theune f872262e08 Fix up float parsing. 2016-01-05 09:46:37 +01:00
Christian Theune 14ebde5289 First hit at providing support for floats in the language. 2016-01-05 00:40:40 +01:00
Shea Levy 9533532ce2 autoCallFunction: Auto-call functors 2015-11-25 11:56:14 -05:00
Eelco Dolstra 5c28943e8f int2String() -> std::to_string() 2015-10-29 13:26:55 +01:00
Eelco Dolstra 51cf4455b2 isFunctor: Simplify 2015-10-08 13:22:11 +02:00
Mathnerd314 8a87521636 forceFunction: allow functors as well 2015-10-08 13:19:44 +02:00
Eelco Dolstra 2bac04c5ff Fix stack consumption 2015-07-31 20:28:25 +02:00
Iwan Aucamp 75837651f1 Output line number on infinite recursion 2015-07-31 20:26:44 +02:00
Eelco Dolstra cb4320c1a0 Cleanup 2015-07-23 23:14:07 +02:00
Eelco Dolstra c8bb2371eb Optimize empty sets
This reduces the number of Bindings allocations by about 10%.
2015-07-23 23:11:08 +02:00
Eelco Dolstra 19eddecc0f Merge branch 'attr-set-hh' of https://github.com/nbp/nix
Conflicts:
	src/libexpr/eval.cc
2015-07-23 22:16:01 +02:00
Eelco Dolstra b83801f8b3 Optimize small lists
The value pointers of lists with 1 or 2 elements are now stored in the
list value itself. In particular, this makes the "concatMap (x: if
cond then [(f x)] else [])" idiom cheaper.
2015-07-23 22:05:09 +02:00
Eelco Dolstra 6bd2c7bb38 OCD: foreach -> C++11 ranged for 2015-07-17 20:13:56 +02:00
Eelco Dolstra f39979c6d3 Make printValue() interruptible
Fixes #572.
2015-07-17 11:33:39 +02:00
Nicolas B. Pierron db21cfa688 Move attribute set data structures into their own header file.
This modification moves Attr and Bindings structures into their own header
file which is dedicated to the attribute set representation. The goal of to
isolate pieces of code which are related to the attribute set
representation. Thus future modifications of the attribute set
representation will only have to modify these files, and not every other
file across the evaluator.
2015-07-14 19:23:17 +02:00
Eelco Dolstra 65f17cd330 Support URLs in $NIX_PATH
This didn't work (despite claims in the manual), because the colon in
"http://" was parsed as a element separator. So handle "://"
specially.
2015-06-17 16:20:11 +02:00
Eelco Dolstra 920f5fd4dd Fix import-from-derivation in restricted eval mode
This relaxes restricted mode to allow access to anything in the
store. In the future, it would be better to allow access to only paths
that have been constructed in the current evaluation (so a hard-coded
/nix/store/blabla in a Nix expression would still be
rejected). However, note that reading /nix/store itself is still
rejected, so you can't use this so get access to things you don't know
about.
2015-05-22 12:18:23 +02:00
Eelco Dolstra 035aeb9547 Fix using restricted mode with chroots 2015-04-16 18:46:17 +02:00
Eelco Dolstra 7ea6ecf855 addToStore(): Take explicit name argument 2015-03-25 17:06:12 +01:00
Eelco Dolstra b005e63ccf Disable scanning for interior pointers
This may remove the "Repeated allocation of very large block"
warnings.
2015-03-19 20:10:08 +01:00
Eelco Dolstra 726f7f7fc9 Fix Boehm API violation
We were calling GC_INIT() after doing an allocation (in the baseEnv
construction), which is not allowed.
2015-03-19 20:02:37 +01:00
Eelco Dolstra da6b704b19 Check return values from malloc/strdup 2015-03-19 14:11:35 +01:00
Eelco Dolstra fa47279440 Print some Boehm GC stats 2015-03-18 16:24:54 +01:00
Eelco Dolstra 7a84143910 valueSize(): Take into account list/bindings/env size 2015-03-18 14:41:28 +01:00
Eelco Dolstra 17c71334e1 forceValueDeep: Add to error prefix 2015-03-06 15:10:12 +01:00
Eelco Dolstra 5badc8f975 Improve error message 2015-03-06 14:24:08 +01:00
Eelco Dolstra 15d2d3c34e Add restricted evaluation mode
If ‘--option restrict-eval true’ is given, the evaluator will throw an
exception if an attempt is made to access any file outside of the Nix
search path. This is primarily intended for Hydra, where we don't want
people doing ‘builtins.readFile ~/.ssh/id_dsa’ or stuff like that.
2015-02-23 15:54:31 +01:00
Shea Levy 4646e94610 ExprConcatStrings: canonicalize concatenated paths 2015-02-19 08:39:25 -05:00
Eelco Dolstra 8aedaf111e Remove canary stuff 2014-12-12 10:59:50 +01:00
Shea Levy 608110804c Make all ExternalValueBase functions const 2014-12-02 10:27:10 -05:00
Shea Levy 320659b0cd Allow external code using libnixexpr to add types
Code that links to libnixexpr (e.g. plugins loaded with importNative, or
nix-exec) may want to provide custom value types and operations on
values of those types. For example, nix-exec is currently using sets
where a custom IO value type would be more appropriate. This commit
provides a generic hook for such types in the form of tExternal and the
ExternalBase virtual class, which contains all functions necessary for
libnixexpr's type-polymorphic functions (e.g. `showType`) to be
implemented.
2014-12-02 10:27:04 -05:00
Eelco Dolstra 4e340a983f forceString(): Accept pos argument 2014-11-25 10:23:36 +01:00
Shea Levy 997defa166 Add functors (callable attribute sets).
With this, attribute sets with a `__functor` attribute can be applied
just like normal functions. This can be used to attach arbitrary
metadata to a function without callers needing to treat it specially.
2014-11-15 16:12:05 -05:00
Eelco Dolstra 3a9b4a1467 Fix more warnings 2014-10-31 08:49:15 +01:00
Eelco Dolstra 6bb4c0b712 mkList: Scrub better
Clearing v.app.right was not enough, because the length field of a
list only takes 32 bits, so the most significant 32 bits of v.app.left
(a.k.a. v.thunk.env) would remain. This could cause Boehm GC to
interpret it as a valid pointer.

This change reduces maximum RSS for evaluating the ‘tested’ job in
nixos/release-small.nix from 1.33 GiB to 0.80 GiB, and runtime by
about 8%.
2014-10-09 13:08:53 +02:00
Eelco Dolstra b6809608cc Get rid of some unnecessary ExprConcatStrings nodes in dynamic attrs
This gives a ~18% speedup in NixOS evaluation (after converting
most calls to hasAttr/getAttr to dynamic attrs).
2014-10-05 01:04:58 +02:00
Eelco Dolstra 1418806969 Show total allocations 2014-10-05 00:39:28 +02:00
Eelco Dolstra a17c23426e printValue(): Don't print <CYCLE> for repeated values 2014-10-01 15:54:40 +02:00
Eelco Dolstra 831fc8ea21 Make forceValueDeep work on values with cycles 2014-09-22 16:05:00 +02:00
Eelco Dolstra 1e0a799bef Rename strictForceValue -> forceValueDeep 2014-09-22 16:05:00 +02:00
Eelco Dolstra 022618c794 Handle cycles when printing a value
So this no longer crashes with a stack overflow:

  nix-instantiate -E --eval 'let as = { x = as; }; in as'

Instead it prints:

  { x = { x = <CYCLE>; }; }
2014-09-22 16:05:00 +02:00
Eelco Dolstra eff120d1b9 Add a function ‘valueSize’
It returns the size of value, including all other values and
environments reachable from it. It is intended for debugging memory
consumption issues.
2014-09-22 16:05:00 +02:00
Eelco Dolstra 93e4f01ee3 Inline Bindings::find() 2014-09-19 16:56:13 +02:00
Eelco Dolstra 5b58991a71 Store Attrs inside Bindings
This prevents a double allocation per attribute set.
2014-09-19 16:49:41 +02:00
Eelco Dolstra 6e5b02bee4 Add some instrumentation for debugging GC leaks 2014-09-17 15:19:07 +02:00
Eelco Dolstra 9472b4157d Fix boost::too_many_args error
Fixes #333.
2014-09-02 22:53:01 +02:00
Eelco Dolstra 11849a320e Use proper quotes everywhere 2014-08-20 18:03:48 +02:00
Eelco Dolstra 5bed74d1b0 Fix warning about non-existant -I directories 2014-08-13 02:57:59 +02:00
Eelco Dolstra ee7fe64c0a == operator: Ignore string context
There really is no case I can think of where taking the context into
account is useful. Mostly it's just very inconvenient.
2014-06-10 14:02:56 +02:00
Eelco Dolstra d8c061e044 Remove ExprBuiltin
It's slower than ExprVar since it doesn't compute a static
displacement. Since we're not using the throw primop in the
implementation of <...> anymore, it's also not really needed.
2014-05-26 17:14:28 +02:00
Eelco Dolstra 39d72640c2 Ensure that -I flags get included in nixPath
Also fixes #261.
2014-05-26 16:52:31 +02:00
Shea Levy eac5841970 Provide a more useful error message when a dynamic attr lookup fails 2014-05-15 17:56:24 +02:00
Eelco Dolstra 8e5fbf4d73 Show position info in attribute selection errors 2014-04-04 22:52:14 +02:00
Eelco Dolstra 4c5faad994 Show position info in Boolean operations 2014-04-04 22:43:52 +02:00
Eelco Dolstra bd9b1d97b4 Show position info in string concatenation / addition errors 2014-04-04 22:19:33 +02:00
Eelco Dolstra a5fe730940 forceString: Show position info 2014-04-04 21:14:11 +02:00
Eelco Dolstra 27b44b8cf7 forceAttrs: Show position info 2014-04-04 19:11:40 +02:00
Eelco Dolstra 96b695ccab forceList: Show position info 2014-04-04 19:05:36 +02:00
Eelco Dolstra b62d36963c forceInt: Show position info 2014-04-04 18:59:29 +02:00
Eelco Dolstra c28de6d96e Pass position information to primop calls
For example:

  error: `tail' called on an empty list, at
    /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/ex-2/default.nix:13:7
2014-04-04 18:59:29 +02:00
Eelco Dolstra b72c8d2e5b Include position info in function application
This allows error messages like:

  error: the anonymous function at `/etc/nixos/configuration.nix:1:1'
    called without required argument `foo', at
    `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/lib/modules.nix:77:59'
2014-04-04 18:59:29 +02:00
Eelco Dolstra 1c2550a2ae boost::shared_ptr -> std::shared_ptr 2014-03-30 00:49:23 +01:00
Shea Levy 049a379ec6 The expr of AttrNames/DynamicAttrDefs is always an ExprConcatStrings 2014-03-10 10:14:50 +01:00
Shea Levy 908e9ce259 If a dynamic attribute name evaluates to null, remove it from the set 2014-03-10 10:14:50 +01:00
Eelco Dolstra 2caab81660 Revert "Make ifs and asserts tail-recursive"
This reverts commit 273322c773.
2014-03-05 16:18:13 +01:00
Eelco Dolstra c9f6232304 Correctly detect infinite recursion in function application
If we're evaluating some application ‘v = f x’, we can't store ‘f’
temporarily in ‘v’, because if ‘f x’ refers to ‘v’, it will get ‘f’
rather than an infinite recursion error.

Unfortunately, this breaks the tail call optimisation introduced in
c897bac549.

Fixes #217.
2014-02-27 21:47:59 +01:00
Eelco Dolstra 81628a6ccc Merge branch 'master' into make
Conflicts:
	src/libexpr/eval.cc
2014-01-21 15:30:01 +01:00
Shea Levy cd49fe4f9b Don't use any syntactic sugar for dynamic attrs
This doesn't change any functionality but moves some behavior out of the
parser and into the evaluator in order to simplify the code.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-12-31 23:56:26 +00:00
Shea Levy 18fefacf7d Dynamic attrs
This adds new syntax for attribute names:

* attrs."${name}" => getAttr name attrs
* attrs ? "${name}" => isAttrs attrs && hasAttr attrs name
* attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def
* { "${name}" = value; } => listToAttrs [{ inherit name value; }]

Of course, it's a bit more complicated than that. The attribute chains
can be arbitrarily long and contain combinations of static and dynamic
parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively
straightforward for the getAttrs/hasAttrs cases but is more complex for
the listToAttrs case due to rules about duplicate attribute definitions.

For attribute sets with dynamic attribute names, duplicate static
attributes are detected at parse time while duplicate dynamic attributes
are detected when the attribute set is forced. So, for example, { a =
null; a.b = null; "${"c"}" = true; } will be a parse-time error, while
{ a = {}; "${"a"}".b = null; c = true; } will be an eval-time error
(technically that case could theoretically be detected at parse time,
but the general case would require full evaluation). Moreover, duplicate
dynamic attributes are not allowed even in cases where they would be
with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but {
a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction
might be relaxed in the future in cases where the static variant would
not be an error, but it is not obvious that that is desirable.

Finally, recursive attribute sets with dynamic attributes have the
static attributes in scope but not the dynamic ones. So rec { a = true;
"${"b"}" = a; } is equivalent to { a = true; b = true; } but rec {
"${"a"}" = true; b = a; } would be an error or use a from the
surrounding scope if it exists.

Note that the getAttr, getAttr or default, and hasAttr are all
implemented purely in the parser as syntactic sugar, while attribute
sets with dynamic attribute names required changes to the AST to be
implemented cleanly.

This is an alternative solution to and closes #167

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-12-31 20:59:49 +00:00
Shea Levy 136f2f7046 Add the ExprBuiltin Expr type to the AST
Certain desugaring schemes may require the parser to use some builtin
function to do some of the work (e.g. currently `throw` is used to
lazily cause an error if a `<>`-style path is not in the search path)
Unfortunately, these names are not reserved keywords, so an expression
that uses such a syntactic sugar will not see the expected behavior
(see tests/lang/eval-okay-redefine-builtin.nix for an example).

This adds the ExprBuiltin AST type, which when evaluated uses the value
from the rootmost variable scope (which of course is initialized
internally and can't shadow any of the builtins).

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-12-31 17:45:47 +00:00
Eelco Dolstra 5a1114ecdb Drop the dependency on libgc in libmain
Instead, libexpr now depends on libgc.  This means commands like
nix-store that don't do any evaluation no longer require libgc.
2013-11-23 20:19:36 +00:00
Eelco Dolstra 06a8ac96e7 Initialise Boehm GC only once 2013-11-23 20:15:57 +00:00
Eelco Dolstra 77c13cdf56 Add a toJSON primop 2013-11-19 00:04:11 +01:00
Eelco Dolstra 285df765b9 Add a primop unsafeGetAttrPos to return the position of an attribute 2013-11-18 22:22:35 +01:00
Eelco Dolstra fc33fd86b7 Add a symbol __curPos that expands to the current source location
I.e. an attribute set { file = <string>; line = <int>; column = <int>; }.
2013-11-18 20:16:02 +01:00
Eelco Dolstra 89e6781cc5 Make function calls show up in stack traces again
Note that adding --show-trace prevents functions calls from being
tail-recursive, so an expression that evaluates without --show-trace
may fail with a stack overflow if --show-trace is given.
2013-11-12 12:51:59 +01:00
Eelco Dolstra c897bac549 Make function calls tail-recursive 2013-11-12 11:32:23 +00:00
Eelco Dolstra 273322c773 Make ifs and asserts tail-recursive
The local Value object prevented g++ from making a tail call.  Not
clear why.  In any case, not using a temporary makes g++ do the tail
call.
2013-11-12 11:32:23 +00:00
Eelco Dolstra 4badd7ed17 Get rid of an intermediary on the stack 2013-11-12 11:32:23 +00:00
Eelco Dolstra ea6bf0c21f Slightly optimize listToAttrs 2013-10-28 07:34:44 +01:00
Eelco Dolstra 5bc41d78ff Rename "attribute sets" to "sets"
We don't have any other kind of sets so calling them attribute sets is
unnecessarily verbose.
2013-10-24 16:41:04 +02:00
Eelco Dolstra 69befd33a9 Remove unnecessary call to forceStringNoCtx 2013-10-24 03:08:34 +02:00
Eelco Dolstra 543d8a5942 Don't require NIX_SHOW_STATS for NIX_COUNT_CALLS 2013-10-24 02:20:54 +02:00
Eelco Dolstra fe95650487 Memoize evalFile() lookups under both the original and resolved name
Previously we only used the resolved name, causing repeated resolution
(e.g. /dir to /dir/default.nix).
2013-10-23 11:19:01 +00:00
Eelco Dolstra f440558acc Don't show <nix/derivation.nix> in stack traces
Messages like

  while evaluating the attribute `outPath' at `/nix/store/212ngf4ph63mp6p1np2bapkfikpakfv7-nix-1.6/share/nix/corepkgs/derivation.nix:18:9':

are redundant, because Nix already shows that it's evaluating a derivation:

  while instantiating the derivation named `firefox-24.0' at `/home/eelco/Dev/nixpkgs/pkgs/applications/networking/browsers/firefox/default.nix:131:5':
  while evaluating the derivation attribute `nativeBuildInputs' at `/home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/default.nix:76:17':
2013-10-17 11:47:38 +02:00
Eelco Dolstra d6a7aa8f48 Revert the behaviour of antiquoted paths to pre-Nix 1.6
Commit 159e621d1a accidentally changed
the behaviour of antiquoted paths, e.g.

  "${/foo}/bar"

used to evaluate to "/nix/store/<hash>-foo/bar" (where /foo gets
copied to the store), but in Nix 1.6 it evaluates to "/foo/bar".  This
is inconsistent, since

  " ${/foo}/bar"

evaluates to " /nix/store/<hash>-foo/bar".  So revert to the old
behaviour.
2013-10-17 00:39:59 +02:00
Eelco Dolstra 7bdb85453d printStats(): Print the size of the symbol table in bytes 2013-10-08 15:37:08 +02:00
Eelco Dolstra 9deb822180 Deduplicate filenames in Pos
This saves ~4 MiB of RAM for NixOS system instantiation, and ~18 MiB
for "nix-env -qa".
2013-10-08 15:36:10 +02:00
Eelco Dolstra b1e3b1a4ac Treat undefined variable errors consistently
Previously, a undefined variable inside a "with" caused an EvalError
(which can be caught), while outside, it caused a ParseError (which
cannot be caught).  Now both cause an UndefinedVarError (which cannot
be caught).
2013-10-08 14:45:36 +02:00
Eelco Dolstra 6b47de580f Show the exact position of undefined variables
In particular, undefined variable errors in a "with" previously didn't
show *any* position information, so this should help a lot in those
cases.
2013-10-08 14:40:51 +02:00
Eelco Dolstra a5e0f64db3 Remove some unused functions 2013-10-08 12:30:23 +00:00
Eelco Dolstra 221a2daf34 Merge VarRef into ExprVar 2013-10-08 14:24:53 +02:00
Eelco Dolstra 176c666f36 Don't show calls to primops in stack traces
Since they don't have location information, they just give you crap
like:

  while evaluating the builtin function `getAttr':
  while evaluating the builtin function `derivationStrict':
  ...
2013-10-07 18:02:32 +02:00
Eelco Dolstra c945f015de Fix segfault in nix-repl / hydra-eval-jobs
If a "with" attribute set fails to evaluate, we have to make sure its
Env record remains unchanged.  Otherwise, repeated evaluation gives a
segfault:

  nix-repl> :a with 0; { a = x; b = x; }
  Added 2 variables.

  nix-repl> a
  error: value is an integer while an attribute set was expected

  nix-repl> b
  Segmentation fault
2013-10-02 15:24:45 +02:00
Eelco Dolstra 07a08bddf0 nix-env: Load files in ~/.nix-defexpr on demand
So if you do "nix-env -qa -A nixos", then other channels won't be
parsed/evaluated at all.
2013-09-03 15:45:32 +02:00
Eelco Dolstra 6f809194d7 Get rid of the parse tree cache
Since we already cache files in normal form (fileEvalCache), caching
parse trees is redundant.

Note that getting rid of this cache doesn't actually save much memory
at the moment, because parse trees are currently not freed / GC'ed.
2013-09-03 13:01:42 +02:00
Eelco Dolstra 57d18df7d0 Add some support code for nix-repl 2013-09-02 18:34:04 +02:00
Eelco Dolstra 33972629d7 Fix whitespace 2013-09-02 16:29:15 +02:00
Shea Levy afc6c1bad6 Simplify inherited attribute handling
This reduces the difference between inherited and non-inherited
attribute handling to the choice of which env to use (in recs and lets)
by setting the AttrDef::e to a new ExprVar in the parser rather than
carrying a separate AttrDef::v VarRef member.

As an added bonus, this allows inherited attributes that inherit from a
with to delay forcing evaluation of the with's attributes.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-08-26 11:31:56 +02:00
Ivan Kozik 34bb806f74 Fix typos, especially those that end up in the Nix manual 2013-08-26 11:15:22 +02:00
Eelco Dolstra d308aeaf53 Store Nix integers as longs
So on 64-bit systems, integers are now 64-bit.

Fixes #158.
2013-08-19 12:35:03 +02:00
Eelco Dolstra 46ffcce0c3 In the profiler output, show function names (if available) 2013-08-02 18:29:23 +00:00
Eelco Dolstra 159e621d1a Overload the ‘+’ operator to support integer addition 2013-08-02 15:21:17 +00:00
Eelco Dolstra 0a470fc345 Make Env smaller
Commit 20866a7031 added a ‘withAttrs’
field to Env, which is annoying because it makes every Env structure
bigger and we allocate millions of them.  E.g. NixOS evaluation took
18 MiB more.  So this commit squeezes ‘withAttrs’ into values[0].
Probably should use a union...
2013-07-31 12:44:21 +02:00
Eelco Dolstra 8ae6d55db1 Don't use NULL 2013-07-31 12:11:14 +02:00
Shea Levy e068f49f7d Avoid thunks when a fromWith var can be looked up without evaluation
Signed-off-by: Shea Levy <shea@shealevy.com>
2013-07-31 11:48:39 +02:00
Shea Levy 20866a7031 Delay evaulation of with attrs until a variable lookup needs them
Evaluation of attribute sets is strict in the attribute names, which
means immediate evaluation of `with` attribute sets rules out some
potentially interesting use cases (e.g. where the attribute names of one
set depend in some way on another but we want to bring those names into
scope for some values in the second set).

The major example of this is overridable self-referential package sets
(e.g. all-packages.nix). With immediate `with` evaluation, the only
options for such sets are to either make them non-recursive and
explicitly use the name of the overridden set in non-overridden one
every time you want to reference another package, or make the set
recursive and use the `__overrides` hack. As shown in the test case that
comes with this commit, though, delayed `with` evaluation allows a nicer
third alternative.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-07-31 11:48:39 +02:00
Eelco Dolstra 18a48d80a0 Show function names in error messages
Functions in Nix are anonymous, but if they're assigned to a
variable/attribute, we can use the variable/attribute name in error
messages, e.g.

while evaluating `concatMapStrings' at `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/strings.nix:18:25':
...
2013-05-16 19:08:02 +02:00
Eelco Dolstra 1b3a03f161 Show which function argument was unexpected
Fixes #116.
2013-05-16 17:56:14 +02:00
Eelco Dolstra 229567293c Shut up a compiler warning 2013-05-16 17:48:19 +02:00
Eelco Dolstra bdd4646338 Revert "Prevent config.h from being clobbered"
This reverts commit 28bba8c44f.
2013-03-08 01:24:59 +01:00
Eelco Dolstra 28bba8c44f Prevent config.h from being clobbered 2013-03-07 23:55:55 +01:00
Eelco Dolstra 5f18cd2e84 Make "${./path} ..." evaluate to a string, not a path
Wacky string coercion semantics caused expressions like

  exec = "${./my-script} params...";

to evaluate to a path (‘/path/my-script params’), because
anti-quotations are desuged to string concatenation:

  exec = ./my-script + " params...";

By constrast, adding a space at the start would yield a string as
expected:

  exec = " ${./my-script} params...";

Now the first example also evaluates to a string.
2013-02-08 20:04:04 +01:00
Eelco Dolstra 8eed07cda4 nix-env -q --out-path: Support multiple outputs
We now print all output paths of a package, e.g.

  openssl-1.0.0i  bin=/nix/store/gq2mvh0wb9l90djvsagln3aqywqmr6vl-openssl-1.0.0i-bin;man=/nix/store/7zwf5r5hsdarl3n86dasvb4chm2xzw9n-openssl-1.0.0i-man;/nix/store/cj7xvk7fjp9q887359j75pw3pzjfmqf1-openssl-1.0.0i

or (in XML mode)

  <item attrPath="openssl" name="openssl-1.0.0i" system="x86_64-linux">
    <output name="bin" path="/nix/store/gq2mvh0wb9l90djvsagln3aqywqmr6vl-openssl-1.0.0i-bin" />
    <output name="man" path="/nix/store/7zwf5r5hsdarl3n86dasvb4chm2xzw9n-openssl-1.0.0i-man" />
    <output name="out" path="/nix/store/cj7xvk7fjp9q887359j75pw3pzjfmqf1-openssl-1.0.0i" />
  </item>
2012-11-28 13:49:44 +01:00
Eelco Dolstra 6c98e6a5de Optionally ignore null-valued derivation attributes
This allows adding attributes like

  attr = if stdenv.system == "bla" then something else null;

without changing the resulting derivation on non-<bla> platforms.

We once considered adding a special "ignore" value for this purpose,
but using null seems more elegant.
2012-11-27 15:01:32 +01:00
Eelco Dolstra 408a7bfac1 nix-instantiate: Fix read-only evaluation 2012-11-26 17:41:10 +01:00
Eelco Dolstra 88164325fa Fix a segfault when auto-calling a "a@{...}" function
Since the called function can return its argument attribute set
(e.g. "a"), the latter should not be allocated on the stack.

Reported by Shea.
2012-11-09 15:09:31 +01:00
Eelco Dolstra 0a7084567f Add a ‘--repair’ flag to nix-instantiate
This allows repairing corrupted derivations and other source files.
2012-10-03 15:09:18 -04:00
Eelco Dolstra 76e88871b2 Templatise tokenizeString() 2012-09-19 15:43:23 -04:00
Eelco Dolstra e94806d030 Merge branch 'master' into no-manifests 2012-08-27 11:09:07 -04:00
Eelco Dolstra 767101824a Avoid concatenating lists of one string 2012-08-13 15:10:29 -04:00
Eelco Dolstra e5c589d271 Don't allocate empty lists
This saves about 4 MB when evaluating a NixOS system configuration.
2012-08-13 15:02:09 -04:00
Eelco Dolstra 3e89ef597c Optimise concatenating a list to an empty list
More precisely, in concatLists, if all lists except one are empty,
then just return the non-empty list.  This reduces the number of list
element allocations by 32% when evaluating a NixOS system
configuration.
2012-08-13 14:58:54 -04:00
Eelco Dolstra 198d0338be Add a primop ‘concatLists’
This can serve as a generic efficient list builder.  For instance, the
function ‘catAttrs’ in Nixpkgs can be rewritten from

  attr: l: fold (s: l: if hasAttr attr s then [(getAttr attr s)] ++ l else l) [] l

to

  attr: l: builtins.concatLists (map (s: if hasAttr attr s then [(getAttr attr s)] else []) l)

Statistics before:

  time elapsed: 1.08683
  size of a value: 24
  environments allocated: 1384376 (35809568 bytes)
  list elements: 6946783 (55574264 bytes)
  list concatenations: 37434
  values allocated: 1760440 (42250560 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18273
  number of thunks: 1297673
  number of thunks avoided: 1380759
  number of attr lookups: 430802
  number of primop calls: 628912
  number of function calls: 1333544

Statistics after (including new catAttrs):

  time elapsed: 0.959854
  size of a value: 24
  environments allocated: 1010198 (26829296 bytes)
  list elements: 1984878 (15879024 bytes)
  list concatenations: 30488
  values allocated: 1589760 (38154240 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18274
  number of thunks: 1040925
  number of thunks avoided: 1038428
  number of attr lookups: 438419
  number of primop calls: 474844
  number of function calls: 959366
2012-08-13 01:53:10 -04:00
Eelco Dolstra 4ccd48ce24 Add a "filter" primop
Evaluation of a NixOS configuration spends quite a lot of time in the
"filter" function in Nixpkgs.  As implemented in Nixpkgs, this is a
O(n^2) operation, so it's a good candidate for providing a more
efficient (i.e. primop) implementation.  Using it gives a ~10% speed
increase and a significant reduction in the number of evaluations.

Statistics before (on a NixOS system config):

  time elapsed: 1.3258
  size of a value: 24
  environments allocated: 1980939 (50127080 bytes)
  list elements: 14679308 (117434464 bytes)
  list concatenations: 50828
  values allocated: 2098938 (50374512 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18271
  number of thunks: 1645752
  number of thunks avoided: 1921196
  number of attr lookups: 430798
  number of primop calls: 838807
  number of function calls: 1930107

Statistics after:

  time elapsed: 1.17982
  size of a value: 24
  environments allocated: 1543334 (39624560 bytes)
  list elements: 9612638 (76901104 bytes)
  list concatenations: 37434
  values allocated: 1854933 (44518392 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18272
  number of thunks: 1392467
  number of thunks avoided: 1507311
  number of attr lookups: 430801
  number of primop calls: 691600
  number of function calls: 1492502
2012-08-13 00:28:08 -04:00
Eelco Dolstra 62f72eb9e1 Add some more evaluations stats 2012-08-12 23:41:48 -04:00
Eelco Dolstra e82767910c Add some basic profiling support to the evaluator
Setting the environment variable NIX_COUNT_CALLS to 1 enables some
basic profiling in the evaluator.  It will count calls to functions
and primops as well as evaluations of attributes.

For example, to see where evaluation of a NixOS configuration spends
its time:

$ NIX_SHOW_STATS=1 NIX_COUNT_CALLS=1 ./src/nix-instantiate/nix-instantiate '<nixos>' -A system --readonly-mode
...
calls to 39 primops:
    239532 head
    233962 tail
    191252 hasAttr
...
calls to 1595 functions:
    224157 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:19'
    221767 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:14'
    221767 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:10'
...
evaluations of 7088 attributes:
    167377 undefined position
    132459 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/attrsets.nix:119:41'
     47322 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/attrsets.nix:13:21'
...
2012-08-12 23:29:28 -04:00
Eelco Dolstra 97421eb5ec Refactor settings processing
Put all Nix configuration flags in a Settings object.
2012-07-30 19:55:41 -04:00
Eelco Dolstra 1217204c81 Remove dead code 2012-07-17 14:07:52 -04:00
Eelco Dolstra f491ae97d4 * Inline some functions and get rid of the indirection through
EvalState::eval().  This gives a 12% speedup on ‘nix-instantiate
  /etc/nixos/nixos/ -A system --readonly-mode’ (from 1.01s to 0.89s).
2012-02-04 13:50:25 +00:00
Eelco Dolstra 2bda12ef3b * Print elapsed evaluation time. 2012-02-04 13:27:11 +00:00
Eelco Dolstra 330df4b4db * Allow comparisons between derivations by comparing the outPath
attributes.
2012-01-19 23:08:47 +00:00
Eelco Dolstra 9fe24c5a0d * Don't create thunks for simple constants (integers, strings, paths)
and allocate them only once.
* Move Value and related functions into value.hh.
2012-01-07 17:26:33 +00:00
Eelco Dolstra b52966e821 * Remove dead code. 2012-01-04 21:47:48 +00:00
Eelco Dolstra 35f2a6ba82 * Don't use dynamic_cast, it's very slow. "nix-instantiate
/etc/nixos/nixos -A system" spent about 10% of its time in
  dynamic_cast.
2012-01-04 21:24:11 +00:00
Eelco Dolstra 921111d197 * Move the implementation of the ‘derivation’ primop into a separate
file.
2012-01-03 14:01:47 +00:00
Shea Levy 24b65937e1 Remove the unused sCurrentOutput symbol 2011-11-06 06:28:34 +00:00
Shea Levy 2721e9f56f Merge from trunk 2011-11-06 00:13:09 +00:00
Eelco Dolstra a12095d3be * In printValueAsXML, handle the case where a "type" attribute is not
a string.  This happens in the NixOS option system.
* Remove a bogus comparison of a unsigned integer with -1.
2011-10-27 19:06:23 +00:00
Shea Levy ffa038f66d Add an sCurrentOutput member to EvalState 2011-09-16 11:30:44 +00:00
Eelco Dolstra 2d663b502d * Cache the result of file evaluation (i.e, memoize evalFile()). This
prevents files from being evaluated and stored as values multiple
  times.  For instance, evaluation of the ‘system’ attribute in NixOS
  causes ‘nixpkgs/pkgs/lib/lists.nix’ to be evaluated 2019 times.

  Caching gives a modest speedup and a decent memory footprint
  reduction (e.g., from 1.44s to 1.28s, and from 81 MiB to 59 MiB with
  GC_INITIAL_HEAP_SIZE=100000 on my system).
2011-08-06 19:45:43 +00:00
Eelco Dolstra 00a724ebc6 * Remove a debug statement. 2011-08-06 18:24:43 +00:00
Eelco Dolstra 07340b8be7 * Add the Nix corepkgs to the end of the search path. This makes it
possible for other Nix expressions to use corepkgs (mostly useful
  for the buildenv function).
2011-08-06 18:23:38 +00:00
Eelco Dolstra 1ecc97b6bd * Add a Nix expression search path feature. Paths between angle
brackets, e.g.

    import <nixpkgs/pkgs/lib>

  are resolved by looking them up relative to the elements listed in
  the search path.  This allows us to get rid of hacks like

    import "${builtins.getEnv "NIXPKGS_ALL"}/pkgs/lib"

  The search path can be specified through the ‘-I’ command-line flag
  and through the colon-separated ‘NIX_PATH’ environment variable,
  e.g.,

    $ nix-build -I /etc/nixos ...

  If a file is not found in the search path, an error message is
  lazily thrown.
2011-08-06 16:05:24 +00:00
Eelco Dolstra 54945a2950 * Refactoring: move parseExprFromFile() and parseExprFromString() into
the EvalState class.
2011-08-06 13:02:55 +00:00
Eelco Dolstra 0a623a10c7 * Allow a default value in attribute selection by writing
x.y.z or default

  (as originally proposed in
  https://mail.cs.uu.nl/pipermail/nix-dev/2009-September/002989.html).

  For instance, an expression like

    stdenv.lib.attrByPath ["features" "ckSched"] false args

  can now be written as

    args.features.ckSched or false
2011-07-13 12:19:57 +00:00
Eelco Dolstra 2b9e29b1c8 * Change the right-hand side of the ‘.’ operator from an attribute to
an attribute path.  This is a refactoring to support default values.
2011-07-06 12:28:57 +00:00
Eelco Dolstra 5637037802 * In the ‘?’ operator, allow attribute paths. For instance, you can
write ‘attrs ? a.b’ to test whether ‘attrs’ has an attribute ‘a’
  containing an attribute ‘b’.  This is more convenient than ‘attrs ?
  a && attrs.a ? b’.

  Slight change in the semantics: it's no longer an error if the
  left-hand side of ‘?’ is not an attribute set.  In that case it just
  returns false.  So, ‘null ? foo’ no longer throws an error.
2011-07-06 10:58:17 +00:00
Eelco Dolstra 538b7caab0 * Don't allocate a big initial GC address space on machines with
little RAM.  Even if the memory isn't actually used, it can cause
  problems with the overcommit heuristics in the kernel.  So use a VM
  space of 25% of RAM, up to 384 MB.
2011-02-10 14:31:04 +00:00
Eelco Dolstra 5a6b039802 * Don't call GC_expand_hp unless we're actually using the garbage
collector.
2011-02-09 22:59:50 +00:00
Eelco Dolstra 0c4828ea05 * new(UseGC) is inexplicably slower than GC_MALLOC, so prefer the
latter.
2010-10-28 12:50:01 +00:00
Eelco Dolstra e11e6fb1c6 * Handle out of memory condition. 2010-10-28 12:29:40 +00:00
Eelco Dolstra 43535499f3 * When allocating an attribute set, reserve enough space for all
elements.  This prevents the vector from having to resize itself.
2010-10-24 20:09:37 +00:00
Eelco Dolstra e0b7fb8f27 * Keep attribute sets in sorted order to speed up attribute lookups.
* Simplify the representation of attributes in the AST.
* Change the behaviour of listToAttrs() in case of duplicate names.
2010-10-24 19:52:33 +00:00
Eelco Dolstra 2dc6d50941 * Don't create thunks for variable lookups (if possible). This
significantly reduces the number of values allocated (e.g. from 8.7m
  to 4.9m for the Bittorrent test).
2010-10-24 14:20:02 +00:00