1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
|
//! Implements `builtins.derivation`, the core of what makes Nix build packages.
use data_encoding::BASE64;
use std::cell::RefCell;
use std::collections::{btree_map, BTreeSet};
use std::rc::Rc;
use tvix_derivation::{Derivation, Hash};
use tvix_eval::builtin_macros::builtins;
use tvix_eval::{AddContext, CoercionKind, ErrorKind, NixAttrs, NixList, Value, VM};
use crate::errors::Error;
use crate::known_paths::{KnownPaths, PathType};
// Constants used for strangely named fields in derivation inputs.
const STRUCTURED_ATTRS: &str = "__structuredAttrs";
const IGNORE_NULLS: &str = "__ignoreNulls";
/// Helper function for populating the `drv.outputs` field from a
/// manually specified set of outputs, instead of the default
/// `outputs`.
fn populate_outputs(vm: &mut VM, drv: &mut Derivation, outputs: NixList) -> Result<(), ErrorKind> {
// Remove the original default `out` output.
drv.outputs.clear();
for output in outputs {
let output_name = output
.force(vm)?
.to_str()
.context("determining output name")?;
if drv
.outputs
.insert(output_name.as_str().into(), Default::default())
.is_some()
{
return Err(Error::DuplicateOutput(output_name.as_str().into()).into());
}
}
Ok(())
}
/// Populate the inputs of a derivation from the build references
/// found when scanning the derivation's parameters.
fn populate_inputs<I: IntoIterator<Item = String>>(
drv: &mut Derivation,
known_paths: &KnownPaths,
references: I,
) {
for reference in references.into_iter() {
match &known_paths[&reference] {
PathType::Plain => {
drv.input_sources.insert(reference.to_string());
}
PathType::Output { name, derivation } => {
match drv.input_derivations.entry(derivation.clone()) {
btree_map::Entry::Vacant(entry) => {
entry.insert(BTreeSet::from([name.clone()]));
}
btree_map::Entry::Occupied(mut entry) => {
entry.get_mut().insert(name.clone());
}
}
}
PathType::Derivation { output_names } => {
match drv.input_derivations.entry(reference.to_string()) {
btree_map::Entry::Vacant(entry) => {
entry.insert(output_names.clone());
}
btree_map::Entry::Occupied(mut entry) => {
entry.get_mut().extend(output_names.clone().into_iter());
}
}
}
}
}
}
/// Populate the output configuration of a derivation based on the
/// parameters passed to the call, flipping the required
/// parameters for a fixed-output derivation if necessary.
///
/// This function handles all possible combinations of the
/// parameters, including invalid ones.
///
/// Due to the support for SRI hashes, and how these are passed along to
/// builtins.derivation, outputHash and outputHashAlgo can have values which
/// need to be further modified before constructing the Derivation struct.
///
/// If outputHashAlgo is an SRI hash, outputHashAlgo must either be an empty
/// string, or the hash algorithm as specified in the (single) SRI (entry).
/// SRI strings with multiple hash algorithms are not supported.
///
/// In case an SRI string was used, the (single) fixed output is populated
/// with the hash algo name, and the hash digest is populated with the
/// (lowercase) hex encoding of the digest.
///
/// These values are only rewritten for the outputs, not what's passed to env.
fn populate_output_configuration(
drv: &mut Derivation,
hash: Option<String>, // in nix: outputHash
hash_algo: Option<String>, // in nix: outputHashAlgo
hash_mode: Option<String>, // in nix: outputHashmode
) -> Result<(), ErrorKind> {
match (hash, hash_algo, hash_mode) {
(Some(digest), Some(algo), hash_mode) => match drv.outputs.get_mut("out") {
None => return Err(Error::ConflictingOutputTypes.into()),
Some(out) => {
let sri_parsed = digest.parse::<ssri::Integrity>();
// SRI strings can embed multiple hashes with different algos, but that's probably not supported
let (digest, algo): (String, String) = match sri_parsed {
Err(e) => {
// unable to parse as SRI, but algo not set
if algo.is_empty() {
// InvalidSRIString doesn't implement PartialEq, but our error does
return Err(Error::InvalidSRIString(e.to_string()).into());
}
// algo is set. Assume the digest is set to some nixbase32.
// TODO: more validation here
(digest.to_string(), algo.to_string())
}
Ok(sri_parsed) => {
// We don't support more than one SRI hash
if sri_parsed.hashes.len() != 1 {
return Err(
Error::UnsupportedSRIMultiple(sri_parsed.hashes.len()).into()
);
}
// grab the first (and only hash)
let sri_parsed_hash = &sri_parsed.hashes[0];
// ensure the algorithm in the SRI is supported
if !(sri_parsed_hash.algorithm == ssri::Algorithm::Sha1
|| sri_parsed_hash.algorithm == ssri::Algorithm::Sha256
|| sri_parsed_hash.algorithm == ssri::Algorithm::Sha512)
{
Error::UnsupportedSRIAlgo(sri_parsed_hash.algorithm.to_string());
}
// if algo is set, it needs to match what the SRI says
if !algo.is_empty() && algo != sri_parsed_hash.algorithm.to_string() {
return Err(Error::ConflictingSRIHashAlgo(
algo.to_string(),
sri_parsed_hash.algorithm.to_string(),
)
.into());
}
// the digest comes base64-encoded. We need to decode, and re-encode as hexlower.
match BASE64.decode(sri_parsed_hash.digest.as_bytes()) {
Err(e) => return Err(Error::InvalidSRIDigest(e).into()),
Ok(sri_digest) => (
data_encoding::HEXLOWER.encode(&sri_digest),
sri_parsed_hash.algorithm.to_string(),
),
}
}
};
// mutate the algo string a bit more, depending on hashMode
let algo = match hash_mode.as_deref() {
None | Some("flat") => algo,
Some("recursive") => format!("r:{}", algo),
Some(other) => {
return Err(Error::InvalidOutputHashMode(other.to_string()).into())
}
};
out.hash = Some(Hash { algo, digest });
}
},
_ => {}
}
Ok(())
}
/// Handles derivation parameters which are not just forwarded to
/// the environment. The return value indicates whether the
/// parameter should be included in the environment.
fn handle_derivation_parameters(
drv: &mut Derivation,
vm: &mut VM,
name: &str,
value: &Value,
val_str: &str,
) -> Result<bool, ErrorKind> {
match name {
IGNORE_NULLS => return Ok(false),
// Command line arguments to the builder.
"args" => {
let args = value.to_list()?;
for arg in args {
drv.arguments.push(strong_coerce_to_string(
vm,
&arg,
"handling command-line builder arguments",
)?);
}
// The arguments do not appear in the environment.
return Ok(false);
}
// Explicitly specified drv outputs (instead of default [ "out" ])
"outputs" => {
let outputs = value
.to_list()
.context("looking at the `outputs` parameter of the derivation")?;
drv.outputs.clear();
populate_outputs(vm, drv, outputs)?;
}
"builder" => {
drv.builder = val_str.to_string();
}
"system" => {
drv.system = val_str.to_string();
}
_ => {}
}
Ok(true)
}
fn strong_coerce_to_string(vm: &mut VM, val: &Value, ctx: &str) -> Result<String, ErrorKind> {
Ok(val
.force(vm)
.context(ctx)?
.coerce_to_string(CoercionKind::Strong, vm)
.context(ctx)?
.as_str()
.to_string())
}
#[builtins(state = "Rc<RefCell<KnownPaths>>")]
mod derivation_builtins {
use super::*;
/// Strictly construct a Nix derivation from the supplied arguments.
///
/// This is considered an internal function, users usually want to
/// use the higher-level `builtins.derivation` instead.
#[builtin("derivationStrict")]
fn builtin_derivation_strict(
state: Rc<RefCell<KnownPaths>>,
vm: &mut VM,
input: Value,
) -> Result<Value, ErrorKind> {
let input = input.to_attrs()?;
let name = input
.select_required("name")?
.force(vm)?
.to_str()
.context("determining derivation name")?;
// Check whether attributes should be passed as a JSON file.
// TODO: the JSON serialisation has to happen here.
if let Some(sa) = input.select(STRUCTURED_ATTRS) {
if sa.force(vm)?.as_bool()? {
return Err(ErrorKind::NotImplemented(STRUCTURED_ATTRS));
}
}
// Check whether null attributes should be ignored or passed through.
let ignore_nulls = match input.select(IGNORE_NULLS) {
Some(b) => b.force(vm)?.as_bool()?,
None => false,
};
let mut drv = Derivation::default();
drv.outputs.insert("out".to_string(), Default::default());
// Configure fixed-output derivations if required.
populate_output_configuration(
&mut drv,
input
.select("outputHash")
.map(|v| strong_coerce_to_string(vm, v, "evaluating the `outputHash` parameter"))
.transpose()?,
input
.select("outputHashAlgo")
.map(|v| {
strong_coerce_to_string(vm, v, "evaluating the `outputHashAlgo` parameter")
})
.transpose()?,
input
.select("outputHashMode")
.map(|v| {
strong_coerce_to_string(vm, v, "evaluating the `outputHashMode` parameter")
})
.transpose()?,
)?;
for (name, value) in input.into_iter_sorted() {
if ignore_nulls && matches!(*value.force(vm)?, Value::Null) {
continue;
}
let val_str = strong_coerce_to_string(vm, &value, "evaluating derivation attributes")?;
// handle_derivation_parameters tells us whether the
// argument should be added to the environment; continue
// to the next one otherwise
if !handle_derivation_parameters(&mut drv, vm, name.as_str(), &value, &val_str)? {
continue;
}
// Most of these are also added to the builder's environment in "raw" form.
if drv
.environment
.insert(name.as_str().to_string(), val_str)
.is_some()
{
return Err(Error::DuplicateEnvVar(name.as_str().to_string()).into());
}
}
// Scan references in relevant attributes to detect any build-references.
let mut refscan = state.borrow().reference_scanner();
drv.arguments.iter().for_each(|s| refscan.scan_str(s));
drv.environment.values().for_each(|s| refscan.scan_str(s));
refscan.scan_str(&drv.builder);
// Each output name needs to exist in the environment, at this
// point initialised as an empty string because that is the
// way of Golang ;)
for output in drv.outputs.keys() {
if drv
.environment
.insert(output.to_string(), String::new())
.is_some()
{
return Err(Error::ShadowedOutput(output.to_string()).into());
}
}
let mut known_paths = state.borrow_mut();
populate_inputs(&mut drv, &known_paths, refscan.finalise());
// At this point, derivation fields are fully populated from
// eval data structures.
drv.validate(false).map_err(Error::InvalidDerivation)?;
let tmp_replacement_str =
drv.calculate_drv_replacement_str(|drv| known_paths.get_replacement_string(drv));
drv.calculate_output_paths(&name, &tmp_replacement_str)
.map_err(Error::InvalidDerivation)?;
let actual_replacement_str =
drv.calculate_drv_replacement_str(|drv| known_paths.get_replacement_string(drv));
let derivation_path = drv
.calculate_derivation_path(&name)
.map_err(Error::InvalidDerivation)?;
known_paths
.add_replacement_string(derivation_path.to_absolute_path(), &actual_replacement_str);
// mark all the new paths as known
let output_names: Vec<String> = drv.outputs.keys().map(Clone::clone).collect();
known_paths.drv(derivation_path.to_absolute_path(), &output_names);
for (output_name, output) in &drv.outputs {
known_paths.output(
&output.path,
output_name,
derivation_path.to_absolute_path(),
);
}
let mut new_attrs: Vec<(String, String)> = drv
.outputs
.into_iter()
.map(|(name, output)| (name, output.path))
.collect();
new_attrs.push(("drvPath".to_string(), derivation_path.to_absolute_path()));
Ok(Value::Attrs(Box::new(NixAttrs::from_iter(
new_attrs.into_iter(),
))))
}
#[builtin("toFile")]
fn builtin_to_file(
state: Rc<RefCell<KnownPaths>>,
_: &mut VM,
name: Value,
content: Value,
) -> Result<Value, ErrorKind> {
let name = name
.to_str()
.context("evaluating the `name` parameter of builtins.toFile")?;
let content = content
.to_str()
.context("evaluating the `content` parameter of builtins.toFile")?;
let mut refscan = state.borrow().reference_scanner();
refscan.scan_str(content.as_str());
let refs = refscan.finalise();
// TODO: fail on derivation references (only "plain" is allowed here)
let path = tvix_derivation::path_with_references(name.as_str(), content.as_str(), refs)
.map_err(Error::InvalidDerivation)?
.to_absolute_path();
state.borrow_mut().plain(&path);
// TODO: actually persist the file in the store at that path ...
Ok(Value::String(path.into()))
}
}
pub use derivation_builtins::builtins as derivation_builtins;
#[cfg(test)]
mod tests {
use super::*;
use tvix_eval::observer::NoOpObserver;
static mut OBSERVER: NoOpObserver = NoOpObserver {};
// Creates a fake VM for tests, which can *not* actually be
// used to force (most) values but can satisfy the type
// parameter.
fn fake_vm() -> VM<'static> {
// safe because accessing the observer doesn't actually do anything
unsafe {
VM::new(
Default::default(),
Box::new(tvix_eval::DummyIO),
&mut OBSERVER,
Default::default(),
)
}
}
#[test]
fn populate_outputs_ok() {
let mut vm = fake_vm();
let mut drv = Derivation::default();
drv.outputs.insert("out".to_string(), Default::default());
let outputs = NixList::construct(
2,
vec![Value::String("foo".into()), Value::String("bar".into())],
);
populate_outputs(&mut vm, &mut drv, outputs).expect("populate_outputs should succeed");
assert_eq!(drv.outputs.len(), 2);
assert!(drv.outputs.contains_key("bar"));
assert!(drv.outputs.contains_key("foo"));
}
#[test]
fn populate_outputs_duplicate() {
let mut vm = fake_vm();
let mut drv = Derivation::default();
drv.outputs.insert("out".to_string(), Default::default());
let outputs = NixList::construct(
2,
vec![Value::String("foo".into()), Value::String("foo".into())],
);
populate_outputs(&mut vm, &mut drv, outputs)
.expect_err("supplying duplicate outputs should fail");
}
#[test]
fn populate_inputs_empty() {
let mut drv = Derivation::default();
let paths = KnownPaths::default();
let inputs = vec![];
populate_inputs(&mut drv, &paths, inputs);
assert!(drv.input_sources.is_empty());
assert!(drv.input_derivations.is_empty());
}
#[test]
fn populate_inputs_all() {
let mut drv = Derivation::default();
let mut paths = KnownPaths::default();
paths.plain("/nix/store/fn7zvafq26f0c8b17brs7s95s10ibfzs-foo");
paths.drv(
"/nix/store/aqffiyqx602lbam7n1zsaz3yrh6v08pc-bar.drv",
&["out"],
);
paths.output(
"/nix/store/zvpskvjwi72fjxg0vzq822sfvq20mq4l-bar",
"out",
"/nix/store/aqffiyqx602lbam7n1zsaz3yrh6v08pc-bar.drv",
);
let inputs: Vec<String> = vec![
"/nix/store/fn7zvafq26f0c8b17brs7s95s10ibfzs-foo".into(),
"/nix/store/aqffiyqx602lbam7n1zsaz3yrh6v08pc-bar.drv".into(),
"/nix/store/zvpskvjwi72fjxg0vzq822sfvq20mq4l-bar".into(),
];
populate_inputs(&mut drv, &paths, inputs);
assert_eq!(drv.input_sources.len(), 1);
assert!(drv
.input_sources
.contains("/nix/store/fn7zvafq26f0c8b17brs7s95s10ibfzs-foo"));
assert_eq!(drv.input_derivations.len(), 1);
assert!(drv
.input_derivations
.contains_key("/nix/store/aqffiyqx602lbam7n1zsaz3yrh6v08pc-bar.drv"));
}
#[test]
fn populate_output_config_std() {
let mut drv = Derivation::default();
populate_output_configuration(&mut drv, None, None, None)
.expect("populate_output_configuration() should succeed");
assert_eq!(drv, Derivation::default(), "derivation should be unchanged");
}
#[test]
fn populate_output_config_fod() {
let mut drv = Derivation::default();
drv.outputs.insert("out".to_string(), Default::default());
populate_output_configuration(
&mut drv,
Some("0000000000000000000000000000000000000000000000000000000000000000".into()),
Some("sha256".into()),
None,
)
.expect("populate_output_configuration() should succeed");
let expected = Hash {
algo: "sha256".into(),
digest: "0000000000000000000000000000000000000000000000000000000000000000".into(),
};
assert_eq!(drv.outputs["out"].hash, Some(expected));
}
#[test]
fn populate_output_config_fod_recursive() {
let mut drv = Derivation::default();
drv.outputs.insert("out".to_string(), Default::default());
populate_output_configuration(
&mut drv,
Some("0000000000000000000000000000000000000000000000000000000000000000".into()),
Some("sha256".into()),
Some("recursive".into()),
)
.expect("populate_output_configuration() should succeed");
let expected = Hash {
algo: "r:sha256".into(),
digest: "0000000000000000000000000000000000000000000000000000000000000000".into(),
};
assert_eq!(drv.outputs["out"].hash, Some(expected));
}
#[test]
/// hash_algo set to sha256, but SRI hash passed
fn populate_output_config_flat_sri_sha256() {
let mut drv = Derivation::default();
drv.outputs.insert("out".to_string(), Default::default());
populate_output_configuration(
&mut drv,
Some("sha256-swapHA/ZO8QoDPwumMt6s5gf91oYe+oyk4EfRSyJqMg=".into()),
Some("sha256".into()),
Some("flat".into()),
)
.expect("populate_output_configuration() should succeed");
let expected = Hash {
algo: "sha256".into(),
digest: "b306a91c0fd93bc4280cfc2e98cb7ab3981ff75a187bea3293811f452c89a8c8".into(), // lower hex
};
assert_eq!(drv.outputs["out"].hash, Some(expected));
}
#[test]
/// hash_algo set to empty string, SRI hash passed
fn populate_output_config_flat_sri() {
let mut drv = Derivation::default();
drv.outputs.insert("out".to_string(), Default::default());
populate_output_configuration(
&mut drv,
Some("sha256-s6JN6XqP28g1uYMxaVAQMLiXcDG8tUs7OsE3QPhGqzA=".into()),
Some("".into()),
Some("flat".into()),
)
.expect("populate_output_configuration() should succeed");
let expected = Hash {
algo: "sha256".into(),
digest: "b3a24de97a8fdbc835b9833169501030b8977031bcb54b3b3ac13740f846ab30".into(), // lower hex
};
assert_eq!(drv.outputs["out"].hash, Some(expected));
}
#[test]
fn handle_outputs_parameter() {
let mut vm = fake_vm();
let mut drv = Derivation::default();
drv.outputs.insert("out".to_string(), Default::default());
let outputs = Value::List(NixList::construct(
2,
vec![Value::String("foo".into()), Value::String("bar".into())],
));
let outputs_str = outputs
.coerce_to_string(CoercionKind::Strong, &mut vm)
.unwrap();
handle_derivation_parameters(&mut drv, &mut vm, "outputs", &outputs, outputs_str.as_str())
.expect("handling 'outputs' parameter should succeed");
assert_eq!(drv.outputs.len(), 2);
assert!(drv.outputs.contains_key("bar"));
assert!(drv.outputs.contains_key("foo"));
}
#[test]
fn handle_args_parameter() {
let mut vm = fake_vm();
let mut drv = Derivation::default();
let args = Value::List(NixList::construct(
3,
vec![
Value::String("--foo".into()),
Value::String("42".into()),
Value::String("--bar".into()),
],
));
let args_str = args
.coerce_to_string(CoercionKind::Strong, &mut vm)
.unwrap();
handle_derivation_parameters(&mut drv, &mut vm, "args", &args, args_str.as_str())
.expect("handling 'args' parameter should succeed");
assert_eq!(
drv.arguments,
vec!["--foo".to_string(), "42".to_string(), "--bar".to_string()]
);
}
}
|