Commit graph

297 commits

Author SHA1 Message Date
Ben Burdette
c7e3d830c1 more debug stuff 2021-09-22 16:22:53 -06:00
Ben Burdette
cd8c232b55 add cout debugging 2021-09-15 16:16:53 -06:00
Ben Burdette
21071bfdeb shared_ptr for StaticEnv 2021-09-14 10:49:22 -06:00
Taeer Bar-Yam
1ffb9f1970 fix parse of /${foo}. was // + foo
I don't think this changes the way any program would behave, but it's a
cleaner internal representation.
2021-08-31 15:55:55 -04:00
Taeer Bar-Yam
8f9429dcab add antiquotations to paths 2021-08-06 06:46:05 -04:00
Maximilian Bosch
7c76964daa
libexpr: misc improvements for proper error position
When working on some more complex Nix code, there are sometimes rather
unhelpful or misleading error messages, especially if coerce-errors are
thrown.

This patch is a first steps towards improving that. I'm happy to file
more changes after that, but I'd like to gather some feedback first.

To summarize, this patch does the following things:

* Attrsets (a.k.a. `Bindings` in `libexpr`) now have a `Pos`. This is
  helpful e.g. to identify which attribute-set in `listToAttrs` is
  invalid.

* The `Value`-struct has a new method named `determinePos` which tries
  to guess the position of a value and falls back to a default if that's
  not possible.

  This can be used to provide better messages if a coercion fails.

* The new `determinePos`-API is used by `builtins.concatMap` now. With
  that change, Nix shows the exact position in the error where a wrong
  value was returned by the lambda.

  To make sure it's still obvious that `concatMap` is the problem,
  another stack-frame was added.

* The changes described above can be added to every other `primop`, but
  first I'd like to get some feedback about the overall approach.
2021-04-13 23:12:38 +02:00
Eelco Dolstra
8d4268d190 Improve error formatting
Changes:

* The divider lines are gone. These were in practice a bit confusing,
  in particular with --show-trace or --keep-going, since then there
  were multiple lines, suggesting a start/end which wasn't the case.

* Instead, multi-line error messages are now indented to align with
  the prefix (e.g. "error: ").

* The 'description' field is gone since we weren't really using it.

* 'hint' is renamed to 'msg' since it really wasn't a hint.

* The error is now printed *before* the location info.

* The 'name' field is no longer printed since most of the time it
  wasn't very useful since it was just the name of the exception (like
  EvalError). Ideally in the future this would be a unique, easily
  googleable error ID (like rustc).

* "trace:" is now just "…". This assumes error contexts start with
  something like "while doing X".

Example before:

  error: --- AssertionError ---------------------------------------------------------------------------------------- nix
  at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix

       6|
       7|   x = assert false; 1;
        |       ^
       8|

  assertion 'false' failed
  ----------------------------------------------------- show-trace -----------------------------------------------------
  trace: while evaluating the attribute 'x' of the derivation 'hello-2.10'
  at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix

     191|         // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) {
     192|           name = "${attrs.pname}-${attrs.version}";
        |           ^
     193|         } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {

Example after:

  error: assertion 'false' failed

         at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix

              6|
              7|   x = assert false; 1;
               |       ^
              8|

         … while evaluating the attribute 'x' of the derivation 'hello-2.10'

         at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix

            191|         // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) {
            192|           name = "${attrs.pname}-${attrs.version}";
               |           ^
            193|         } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-21 11:02:09 +01:00
Eelco Dolstra
75efa42134 Move <nix/fetchurl.nix> into the nix binary
This makes the statically linked nix binary just work, without needing
any additional files.
2020-12-22 14:43:20 +01:00
Eelco Dolstra
5999978a05 Make Headers an optional argument 2020-09-29 13:05:19 +02:00
Gregory Hale
faa5607f54 Merge remote-tracking branch 'origin/master' into github-api-token 2020-09-25 12:10:58 -04:00
Eelco Dolstra
236d9ee7f7 lstat() cleanup 2020-09-23 19:17:28 +02:00
Greg Hale
a303c0b6dc Fetch commits from github/gitlab using Auth header
`nix flake info` calls the github 'commits' API, which requires
authorization when the repository is private. Currently this request
fails with a 404.

This commit adds an authorization header when calling the 'commits' API.
It also changes the way that the 'tarball' API authenticates, moving the
user's token from a query parameter into the Authorization header.

The query parameter method is recently deprecated and will be disallowed
in November 2020. Using them today triggers a warning email.
2020-09-16 13:46:48 -04:00
Eelco Dolstra
54712aaf8a Merge remote-tracking branch 'origin/master' into flakes 2020-07-06 16:40:10 +02:00
Ben Burdette
5ae498872a assert for invalid fileorigin 2020-07-02 07:14:40 -06:00
Ben Burdette
1d43a6e123 use plain errPos instead of nixCode; fix tests 2020-06-23 15:30:13 -06:00
Ben Burdette
e6f93b94fc Merge branch 'master' into caveman-LOCs 2020-06-18 13:07:53 -06:00
Eelco Dolstra
1524752c17 Merge remote-tracking branch 'origin/master' into flakes 2020-06-17 10:26:52 +02:00
Eelco Dolstra
ccfa6b3eee Give better error message about <...> in pure eval mode 2020-06-15 16:12:27 +02:00
Eelco Dolstra
1fb762d11f Get rid of explicit ErrorInfo constructors 2020-06-15 14:06:58 +02:00
Eelco Dolstra
950b46821f Remove TreeInfo
The attributes previously stored in TreeInfo (narHash, revCount,
lastModified) are now stored in Input. This makes it less arbitrary
what attributes are stored where.

As a result, the lock file format has changed. An entry like

    "info": {
      "lastModified": 1585405475,
      "narHash": "sha256-bESW0n4KgPmZ0luxvwJ+UyATrC6iIltVCsGdLiphVeE="
    },
    "locked": {
      "owner": "NixOS",
      "repo": "nixpkgs",
      "rev": "b88ff468e9850410070d4e0ccd68c7011f15b2be",
      "type": "github"
    },

is now stored as

    "locked": {
      "owner": "NixOS",
      "repo": "nixpkgs",
      "rev": "b88ff468e9850410070d4e0ccd68c7011f15b2be",
      "type": "github",
      "lastModified": 1585405475,
      "narHash": "sha256-bESW0n4KgPmZ0luxvwJ+UyATrC6iIltVCsGdLiphVeE="
    },

The 'Input' class is now a dumb set of attributes. All the fetcher
implementations subclass InputScheme, not Input. This simplifies the
API.

Also, fix substitution of flake inputs. This was broken since lazy
flake fetching started using fetchTree internally.
2020-05-30 00:44:11 +02:00
Ben Burdette
b7057fa627 remove error-demo from make; clean up comment 2020-05-21 16:04:18 -06:00
Ben Burdette
6a420d672c print LOC for stdin, string args 2020-05-20 22:18:26 -06:00
Ben Burdette
ef9dd9f9bc formatting and a few minor changes 2020-05-13 15:56:39 -06:00
Ben Burdette
72ecccee57 convert to logWarning format 2020-05-12 12:19:34 -06:00
Ben Burdette
7c3138844c more pos reporting 2020-05-11 17:34:57 -06:00
Ben Burdette
631642c5b4 new format for pos 2020-05-11 16:58:08 -06:00
Ben Burdette
59b1f5c701 Merge branch 'master' into errors-phase-2 2020-05-11 14:35:30 -06:00
Ben Burdette
55eb717148 add pos to errorinfo, remove from hints 2020-05-08 18:18:28 -06:00
Ben Burdette
ab6f0b9641 convert some printError calls to logError 2020-05-03 08:01:25 -06:00
Ben Burdette
e4fb9a3849 remove 'format' from Error constructor calls 2020-04-21 17:07:07 -06:00
Domen Kožar
a693a9fa4b
Attach pos to if expression errors 2020-04-09 09:45:15 +02:00
Nikola Knezevic
7867685dcd after flake rebase 2020-04-08 22:26:57 +02:00
Nikola Knezevic
f5095594e7 datatransfer.{cc,hh} -> filetransfer.{cc,hh} 2020-04-08 22:26:57 +02:00
Nikola Knezevic
c4c1ae0a00 DownloadError -> DataTransferError 2020-04-08 22:26:57 +02:00
Nikola Knezevic
741e9012d3 Rename src/lib/download.* to src/lib/datatransfer.* 2020-04-08 22:26:57 +02:00
Eelco Dolstra
9ed097db7b
Merge pull request #3468 from Infinisil/functionArgsPositions
Make function arguments retain position info
2020-04-08 15:29:39 +02:00
Eelco Dolstra
462421d345 Backport libfetchers from the flakes branch
This provides a pluggable mechanism for defining new fetchers. It adds
a builtin function 'fetchTree' that generalizes existing fetchers like
'fetchGit', 'fetchMercurial' and 'fetchTarball'. 'fetchTree' takes a
set of attributes, e.g.

  fetchTree {
    type = "git";
    url = "https://example.org/repo.git";
    ref = "some-branch";
    rev = "abcdef...";
  }

The existing fetchers are just wrappers around this. Note that the
input attributes to fetchTree are the same as flake input
specifications and flake lock file entries.

All fetchers share a common cache stored in
~/.cache/nix/fetcher-cache-v1.sqlite. This replaces the ad hoc caching
mechanisms in fetchGit and download.cc (e.g. ~/.cache/nix/{tarballs,git-revs*}).

This also adds support for Git worktrees (c169ea5904).
2020-04-07 09:03:14 +02:00
Silvan Mosberger
c34e96f7e0
Make function arguments retain position info
This allows querying the location of function arguments. E.g.

  builtins.unsafeGetAttrPos "x" (builtins.functionArgs ({ x }: null))

  => { column = 57; file = "/home/infinisil/src/nix/inst/test.nix"; line = 1; }
2020-04-02 05:52:52 +02:00
Eelco Dolstra
e02481ded2 parseExprFromString(): Use std::string_view 2020-03-11 16:56:29 +01:00
Eelco Dolstra
acb71aa5c6 Tweak error message 2019-12-15 10:44:53 +01:00
Dima
d89d9958a7 bugfix: Adding depth limit to resolveExprPath
There is no termination condition for evaluation of cyclical
expression paths which can lead to infinite loops. This addresses
one spot in the parser in a similar fashion as utils.cc/canonPath
does.

This issue can be reproduced by something like:

```
ln -s a b
ln -s b a

nix-instantiate -E 'import ./a'
```
2019-12-13 14:51:30 +01:00
Eelco Dolstra
1ec6e6e11e
Add feature to disable URL literals
E.g.

  $ nix-build '<nixpkgs>' -A hello --experimental-features no-url-literals
  error: URL literals are disabled, at /nix/store/vsjamkzh15r3c779q2711az826hqgvzr-nixpkgs-20.03pre194957.bef773ed53f/nixpkgs/pkgs/top-level/all-packages.nix:1236:11

Helps with implementing https://github.com/NixOS/rfcs/pull/45.
2019-11-26 19:48:34 +01:00
Eelco Dolstra
926d3e5bb0
Fix Bison 2.4 warning 2019-10-09 22:57:37 +02:00
Eelco Dolstra
99b73fb507
OCD performance fix: {find,count}+insert => insert 2019-10-09 16:06:29 +02:00
Eelco Dolstra
f8b30338ac
Refactor downloadCached() interface
(cherry picked from commit df3f5a78d5)
2019-06-24 22:12:26 +02:00
Eelco Dolstra
dc29e9fb47
downloadCached: Return ETag
(cherry picked from commit 529add316c)
2019-06-24 21:58:33 +02:00
Eelco Dolstra
22f2744afd
Iterate over references 2019-05-28 23:05:08 +02:00
Eelco Dolstra
9eaebbf575
Merge branch 'attrPaths' of https://github.com/NinjaTrappeur/nix 2019-05-28 22:59:05 +02:00
Eelco Dolstra
f32fbf952d Fix Bison 3.3 warning 2019-03-27 21:09:31 +01:00
volth
deaa6e9a34
parser.y: right-associativity of -> 2018-07-23 07:28:48 +00:00
volth
85fe4a819c
parser.y: fix assoc of -> and < > <= >=
The parser allowed senseless `a > b > c` but disallowed `a -> b -> c` which seems valid
It might be a typo
2018-07-21 15:24:51 +00:00
Eelco Dolstra
f3c85f9eb3
Revert "Throw a specific error for incomplete parse errors."
This reverts commit 6498adb002. We don't
actually use IncompleteParseError in 'nix repl'.
2018-05-11 11:40:50 +02:00
Eelco Dolstra
53ec5ac69f
Fix some random -Wconversion warnings 2018-05-02 13:56:34 +02:00
Félix Baylac-Jacqué
00584bb091
parser: Allow mixed nested and top-level attrpaths
Fixes #2077.
2018-04-18 18:44:38 +02:00
Eelco Dolstra
6cf7c6a6b0
Remove git:// support in NIX_PATH
This didn't support specifying a revision/branch, and was restricted
to git:// URIs (since https:// or ssh:// would be ambiguous).
2017-11-03 13:55:31 +01:00
Eelco Dolstra
72cd52c3cd
builtins.fetchgit: Support importing a working tree
For example, you can write

  src = fetchgit ./.;

and if ./. refers to an unclean working tree, that tree will be copied
to the Nix store. This removes the need for "cleanSource".
2017-10-30 19:59:25 +01:00
Eelco Dolstra
e38382895d
builtins.fetchGit: Return an attrset with revision info
This adds rev, shortRev and revCount attributes, equal to what Hydra
provides. E.g.

  $ nix eval '(fetchGit https://github.com/NixOS/patchelf.git)'
  { outPath = "/nix/store/ghigrkw02l440g8vfxa9wj4c3zpfmw99-source"; rev = "29c085fd9d3fc972f75b3961905d6b4ecce7eb2b"; revCount = 303; shortRev = "29c085f"; }
2017-10-30 11:49:03 +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
4c9ff89c26
nix-build/nix-shell: Eliminate call to nix-instantiate / nix-store
Note that this removes the need for a derivation symlink, so the
--drv-path and --add-drv-link flags now do nothing.
2017-07-26 17:29:09 +02:00
Eelco Dolstra
465cb68244
Figure out the user's home directory if $HOME is not set 2017-05-05 17:08:23 +02:00
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
c55bf085eb printMsg(lvlError, ...) -> printError(...) etc. 2016-09-21 16:54:53 +02:00
Eelco Dolstra
90ad02bf62 Enable HTTP/2 support
The binary cache store can now use HTTP/2 to do lookups. This is much
more efficient than HTTP/1.1 due to multiplexing: we can issue many
requests in parallel over a single TCP connection. Thus it's no longer
necessary to use a bunch of concurrent TCP connections (25 by
default).

For example, downloading 802 .narinfo files from
https://cache.nixos.org/, using a single TCP connection, takes 11.8s
with HTTP/1.1, but only 0.61s with HTTP/2.

This did require a fairly substantial rewrite of the Downloader class
to use the curl multi interface, because otherwise curl wouldn't be
able to do multiplexing for us. As a bonus, we get connection reuse
even with HTTP/1.1. All downloads are now handled by a single worker
thread. Clients call Downloader::enqueueDownload() to tell the worker
thread to start the download, getting a std::future to the result.
2016-09-14 16:36:02 +02:00
Eelco Dolstra
d8bf0d4859 Support Git repos in the Nix path
E.g.

  $ nix-build -I nixpkgs=git://github.com/NixOS/nixpkgs '<nixpkgs>' -A hello

This is not extremely useful yet because you can't specify a
branch/revision.
2016-04-29 21:07:47 +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
e9c50064b5 Add an HTTP binary cache store
Allowing stuff like

  NIX_REMOTE=https://cache.nixos.org nix-store -qR /nix/store/x1p1gl3a4kkz5ci0nfbayjqlqmczp1kq-geeqie-1.1

or

  NIX_REMOTE=https://cache.nixos.org nix-store --export /nix/store/x1p1gl3a4kkz5ci0nfbayjqlqmczp1kq-geeqie-1.1 | nix-store --import
2016-02-29 18:15:20 +01:00
Scott Olson
6498adb002 Throw a specific error for incomplete parse errors.
`nix-repl` will use this for deciding whether to keep waiting for input or
error out right away.
2016-02-24 04:32:21 -06:00
Eelco Dolstra
b3e8d72770 Merge pull request #762 from ctheune/ctheune-floats
Implement floats
2016-02-12 12:49:59 +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
Christian Theune
14ebde5289 First hit at providing support for floats in the language. 2016-01-05 00:40:40 +01:00
Eelco Dolstra
6bd2c7bb38 OCD: foreach -> C++11 ranged for 2015-07-17 20:13:56 +02:00
Guillaume Maudoux
65e4dcd69b Fix the hack that resets the scanner state. 2015-07-03 13:53:36 +02:00
Eelco Dolstra
6519f06f39 nix-env/nix-instantiate/nix-build: Support URIs
For instance, you can install Firefox from a specific Nixpkgs revision
like this:

  $ nix-env -f 63def04891.tar.gz -iA firefox

Or build a package from the latest nixpkgs-unstable channel:

  $ nix-build https://nixos.org/channels/nixpkgs-unstable/nixexprs.tar.xz -A hello
2015-05-06 14:54:31 +02:00
Eelco Dolstra
9451ef3731 Allow URLs in the Nix search path
E.g. to install "hello" from the latest Nixpkgs:

  $ nix-build '<nixpkgs>' -A hello -I nixpkgs=https://nixos.org/channels/nixpkgs-unstable/nixexprs.tar.xz

Or to install a specific version of NixOS:

  $ nixos-rebuild switch -I nixpkgs=63def04891.tar.gz
2015-05-05 17:09:42 +02:00
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
Eelco Dolstra
c33244d7c1 Merge branch 'tilde-paths' of https://github.com/shlevy/nix 2015-02-19 14:55:06 +01:00
Shea Levy
c4653afbcd tilde paths: The rest of the string has to start with a slash anyway 2015-02-19 08:52:13 -05:00
Shea Levy
e3e38a048e tilde paths: construct the entire path at parse time 2015-02-19 08:51:21 -05:00
Shea Levy
4b7c9f834c tilde paths: get HOME at parse time 2015-02-19 08:49:10 -05:00
Eelco Dolstra
9bedd9b09b Remove obsolete reference to ~ operator 2015-02-19 14:41:22 +01:00
Shea Levy
e0953d53de Allow the leading component of a path to be a ~ 2015-02-19 08:05:16 -05:00
Eelco Dolstra
153a943de7 Show position info for failing <...> lookups 2015-01-07 13:43:55 +01:00
Eelco Dolstra
4e0607369e Pedantry 2014-12-14 01:51:14 +01:00
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
11849a320e Use proper quotes everywhere 2014-08-20 18:03:48 +02:00
Eelco Dolstra
3d221a7bb1 Rename nixPath to __nixPath
The name ‘nixPath’ breaks existing code.
2014-07-30 11:28:39 +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
62a6eeb1f3 Make the Nix search path declarative
Nix search path lookups like <nixpkgs> are now desugared to ‘findFile
nixPath <nixpkgs>’, where ‘findFile’ is a new primop. Thus you can
override the search path simply by saying

  let
    nixPath = [ { prefix = "nixpkgs"; path = "/my-nixpkgs"; } ];
  in ... <nixpkgs> ...

In conjunction with ‘scopedImport’ (commit
c273c15cb1), the Nix search path can be
propagated across imports, e.g.

  let

    overrides = {
      nixPath = [ ... ] ++ builtins.nixPath;
      import = fn: scopedImport overrides fn;
      scopedImport = attrs: fn: scopedImport (overrides // attrs) fn;
      builtins = builtins // overrides;
    };

  in scopedImport overrides ./nixos
2014-05-26 17:02:22 +02:00
Eelco Dolstra
39d72640c2 Ensure that -I flags get included in nixPath
Also fixes #261.
2014-05-26 16:52:31 +02:00
Eelco Dolstra
c273c15cb1 Add primop ‘scopedImport’
‘scopedImport’ works like ‘import’, except that it takes a set of
attributes to be added to the lexical scope of the expression,
essentially extending or overriding the builtin variables.  For
instance, the expression

  scopedImport { x = 1; } ./foo.nix

where foo.nix contains ‘x’, will evaluate to 1.

This has a few applications:

* It allows getting rid of function argument specifications in package
  expressions. For instance, a package expression like:

    { stdenv, fetchurl, libfoo }:

    stdenv.mkDerivation { ... buildInputs = [ libfoo ]; }

  can now we written as just

    stdenv.mkDerivation { ... buildInputs = [ libfoo ]; }

  and imported in all-packages.nix as:

    bar = scopedImport pkgs ./bar.nix;

  So whereas we once had dependencies listed in three places
  (buildInputs, the function, and the call site), they now only need
  to appear in one place.

* It allows overriding builtin functions. For instance, to trace all
  calls to ‘map’:

  let
    overrides = {
      map = f: xs: builtins.trace "map called!" (map f xs);

      # Ensure that our override gets propagated by calls to
      # import/scopedImport.
      import = fn: scopedImport overrides fn;

      scopedImport = attrs: fn: scopedImport (overrides // attrs) fn;

      # Also update ‘builtins’.
      builtins = builtins // overrides;
    };
  in scopedImport overrides ./bla.nix

* Similarly, it allows extending the set of builtin functions. For
  instance, during Nixpkgs/NixOS evaluation, the Nixpkgs library
  functions could be added to the default scope.

There is a downside: calls to scopedImport are not memoized, unlike
import. So importing a file multiple times leads to multiple parsings
/ evaluations. It would be possible to construct the AST only once,
but that would require careful handling of variables/environments.
2014-05-26 14:26:29 +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
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
Shea Levy
049a379ec6 The expr of AttrNames/DynamicAttrDefs is always an ExprConcatStrings 2014-03-10 10:14:50 +01:00
Eelco Dolstra
f14ef84a51 Warn about missing -I paths
Fixes #121.  Note that we don't warn about missing $NIX_PATH entries
because it's intended that some may be missing (cf. the default
$NIX_PATH on NixOS, which includes paths like /etc/nixos/nixpkgs for
backward compatibility).
2014-02-26 15:21:56 +01:00
Eelco Dolstra
94f9c14d52 Fix some clang warnings 2014-01-21 18:29:55 +01:00
Eelco Dolstra
68cde53c47 Fix building against Bison 3.0.2 2014-01-21 15:34:04 +01:00
Shea Levy
f5e5793cd2 Bare dynamic attrs: Match interpolation semantics
Signed-off-by: Shea Levy <shea@shealevy.com>
2014-01-14 14:00:15 +01:00
Shea Levy
f9913f4422 Allow "bare" dynamic attrs
Now, in addition to a."${b}".c, you can write a.${b}.c (applicable
wherever dynamic attributes are valid).

Signed-off-by: Shea Levy <shea@shealevy.com>
2014-01-14 14:00:15 +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
6f3a51809a Fold dynamic binds handling into addAttr
Since addAttr has to iterate through the AttrPath we pass it, it makes
more sense to just iterate through the AttrNames in addAttr instead. As
an added bonus, this allows attrsets where two dynamic attribute paths
have the same static leading part (see added test case for an example
that failed previously).

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-12-31 17:57:10 -05:00
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
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
b8034e5581 Ensure proper type checking/coercion of "${expr}"
Now we only rewrite "${expr}" to expr if expr is a string literal.
2013-10-17 00:57:24 +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
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
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
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
3d77b28eac Add comparison operators ‘<’, ‘<=’, ‘>’ and ‘>=’ 2013-08-02 18:39:40 +02:00
Eelco Dolstra
47701677e8 Add integer ‘-’, ‘*’ and ‘/’ operators 2013-08-02 16:03:02 +00:00
Eelco Dolstra
5d147e125c Add a unary integer negation operator
This allows saying "-1" instead of "builtins.sub 0 1".
2013-08-02 15:43:31 +00:00
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
804709706c Fix building against Bison 2.6 2013-03-14 18:31:08 +01:00
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
767101824a Avoid concatenating lists of one string 2012-08-13 15:10:29 -04:00
Eelco Dolstra
00c98a6bef Use Bison 2.5 2012-04-13 14:28:26 +02:00
Eelco Dolstra
9d091ee99a * Handle the case where the search path element is a regular file. 2011-08-06 18:45:28 +00:00
Eelco Dolstra
c7101dac0b * Allow redirections in search path entries. E.g. if you have a
directory

    /home/eelco/src/stdenv-updates

  that you want to use as the directory for import such as

    with (import <nixpkgs> { });

  then you can say

    $ nix-build -I nixpkgs=/home/eelco/src/stdenv-updates
2011-08-06 17:48:57 +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
d5d4dcd4c9 * Allow attribute names to be strings. Based on the
allow-arbitrary-strinsg-in-names patch by Marc Weber.
2011-07-13 15:53:24 +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
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
b2ba62170c * Optimise string constants by putting them in the symbol table. 2010-10-23 21:11:59 +00:00
Eelco Dolstra
705868a8a9 * Make sure that config.h is included before the system headers,
because it defines _FILE_OFFSET_BITS.  Without this, on 
  OpenSolaris the system headers define it to be 32, and then 
  the 32-bit stat() ends up being called with a 64-bit "struct 
  stat", or vice versa.

  This also ensures that we get 64-bit file sizes everywhere.

* Remove the redundant call to stat() in parseExprFromFile().
  The file cannot be a symlink because that's the exit condition
  of the loop before.
2010-10-04 17:55:38 +00:00
Eelco Dolstra
01e58adce0 * Store position info for inherited attributes. 2010-05-07 12:43:57 +00:00
Eelco Dolstra
84ce7ac76f * Store attribute positions in the AST and report duplicate attribute
errors with position info.
* For all positions, use the position of the first character of the
  first token, rather than the last character of the first token plus
  one.
2010-05-06 16:46:48 +00:00
Eelco Dolstra
ebade9ff8b * Check for duplicate attribute names / function arguments. `make
check' now succeeds :-)
* An attribute set such as `{ foo = { enable = true; };
  foo.port = 23; }' now parses.  It was previously rejected, but I'm
  too lazy to implement the check.  (The only reason to reject it is
  that the reverse, `{ foo.port = 23; foo = { enable = true; }; }', is
  rejected, which is kind of ugly.)
2010-04-22 11:02:24 +00:00
Eelco Dolstra
267dc693d2 * Fix builtins. 2010-04-14 22:59:39 +00:00
Eelco Dolstra
9985230c00 * After parsing, compute level/displacement pairs for each variable
use site, allowing environments to be stores as vectors of values
  rather than maps.  This should speed up evaluation and reduce the
  number of allocations.
2010-04-14 14:42:32 +00:00
Eelco Dolstra
7d47498b5e * Evaluate lets directly (i.e. without desugaring to `rec { attrs...;
<let-body> = e; }.<let-body>).  This prevents the unnecessary
  allocation of an attribute set.
2010-04-13 13:42:25 +00:00
Eelco Dolstra
ac1e8f40d4 * Use a symbol table to represent identifiers and attribute names
efficiently.  The symbol table ensures that there is only one copy
  of each symbol, thus allowing symbols to be compared efficiently
  using a pointer equality test.
2010-04-13 12:25:42 +00:00
Eelco Dolstra
10e8b1fd15 * Finished the ATerm-less parser. 2010-04-12 23:33:23 +00:00
Eelco Dolstra
d4f0b0fc6c * Indented strings. 2010-04-12 22:03:27 +00:00
Eelco Dolstra
a60317f20f * More missing constructs. 2010-04-12 21:21:24 +00:00
Eelco Dolstra
4d6ad5be17 * Don't use ATerms for the abstract syntax trees anymore. Not
finished yet.
2010-04-12 18:30:11 +00:00
Eelco Dolstra
ed711f73bc * Don't use ATerms to represent integers in the lexer. 2010-04-12 10:38:18 +00:00
Eelco Dolstra
a5ece7d016 * Removed the `~' operator. 2010-04-01 16:59:07 +00:00
Eelco Dolstra
55e207b2dc * Cache parse trees to prevent repeated parsing of imported Nix
expressions.
2010-03-31 16:14:32 +00:00