diff options
| -rw-r--r-- | corp/tvixbolt/Cargo.lock | 78 | ||||
| -rw-r--r-- | tvix/Cargo.lock | 80 | ||||
| -rw-r--r-- | tvix/Cargo.nix | 207 | ||||
| -rw-r--r-- | tvix/eval/Cargo.toml | 1 | ||||
| -rw-r--r-- | tvix/eval/src/value/mod.rs | 2 | ||||
| -rw-r--r-- | tvix/eval/src/vm.rs | 2 | ||||
| -rw-r--r-- | tvix/eval/src/vm/generators.rs | 538 |
7 files changed, 897 insertions, 11 deletions
diff --git a/corp/tvixbolt/Cargo.lock b/corp/tvixbolt/Cargo.lock index 479e4d49e5..11ff533616 100644 --- a/corp/tvixbolt/Cargo.lock +++ b/corp/tvixbolt/Cargo.lock @@ -142,6 +142,36 @@ source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "ec90ff4d0fe1f57d600049061dc6bb68ed03c7d2fbd697274c41805dcb3f8608" [[package]] +name = "genawaiter" +version = "0.99.1" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "c86bd0361bcbde39b13475e6e36cb24c329964aa2611be285289d1e4b751c1a0" +dependencies = [ + "genawaiter-macro", + "genawaiter-proc-macro", + "proc-macro-hack", +] + +[[package]] +name = "genawaiter-macro" +version = "0.99.1" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "0b32dfe1fdfc0bbde1f22a5da25355514b5e450c33a6af6770884c8750aedfbc" + +[[package]] +name = "genawaiter-proc-macro" +version = "0.99.1" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "784f84eebc366e15251c4a8c3acee82a6a6f427949776ecb88377362a9621738" +dependencies = [ + "proc-macro-error 0.4.12", + "proc-macro-hack", + "proc-macro2", + "quote", + "syn", +] + +[[package]] name = "getrandom" version = "0.2.8" source = "registry+https://github.com/rust-lang/crates.io-index" @@ -456,14 +486,40 @@ checksum = "478c572c3d73181ff3c2539045f6eb99e5491218eae919370993b890cdbdd98e" [[package]] name = "proc-macro-error" +version = "0.4.12" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "18f33027081eba0a6d8aba6d1b1c3a3be58cbb12106341c2d5759fcd9b5277e7" +dependencies = [ + "proc-macro-error-attr 0.4.12", + "proc-macro2", + "quote", + "syn", + "version_check", +] + +[[package]] +name = "proc-macro-error" version = "1.0.4" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c" dependencies = [ - "proc-macro-error-attr", + "proc-macro-error-attr 1.0.4", + "proc-macro2", + "quote", + "syn", + "version_check", +] + +[[package]] +name = "proc-macro-error-attr" +version = "0.4.12" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "8a5b4b77fdb63c1eca72173d68d24501c54ab1269409f6b672c85deb18af69de" +dependencies = [ "proc-macro2", "quote", "syn", + "syn-mid", "version_check", ] @@ -479,6 +535,12 @@ dependencies = [ ] [[package]] +name = "proc-macro-hack" +version = "0.5.20+deprecated" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "dc375e1527247fe1a97d8b7156678dfe7c1af2fc075c9a4db3690ecd2a148068" + +[[package]] name = "proc-macro2" version = "1.0.50" source = "registry+https://github.com/rust-lang/crates.io-index" @@ -694,6 +756,17 @@ dependencies = [ ] [[package]] +name = "syn-mid" +version = "0.5.3" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "baa8e7560a164edb1621a55d18a0c59abf49d360f47aa7b821061dd7eea7fac9" +dependencies = [ + "proc-macro2", + "quote", + "syn", +] + +[[package]] name = "tabwriter" version = "1.2.1" source = "registry+https://github.com/rust-lang/crates.io-index" @@ -778,6 +851,7 @@ dependencies = [ "codemap", "codemap-diagnostic", "dirs", + "genawaiter", "imbl", "lazy_static", "lexical-core", @@ -982,7 +1056,7 @@ checksum = "5fab79082b556d768d6e21811869c761893f0450e1d550a67892b9bce303b7bb" dependencies = [ "boolinator", "lazy_static", - "proc-macro-error", + "proc-macro-error 1.0.4", "proc-macro2", "quote", "syn", diff --git a/tvix/Cargo.lock b/tvix/Cargo.lock index fa3ac2269b..913d88b9fc 100644 --- a/tvix/Cargo.lock +++ b/tvix/Cargo.lock @@ -364,7 +364,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "684a277d672e91966334af371f1a7b5833f9aa00b07c84e92fbce95e00208ce8" dependencies = [ "heck", - "proc-macro-error", + "proc-macro-error 1.0.4", "proc-macro2 1.0.50", "quote 1.0.23", "syn 1.0.107", @@ -820,6 +820,36 @@ dependencies = [ ] [[package]] +name = "genawaiter" +version = "0.99.1" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "c86bd0361bcbde39b13475e6e36cb24c329964aa2611be285289d1e4b751c1a0" +dependencies = [ + "genawaiter-macro", + "genawaiter-proc-macro", + "proc-macro-hack", +] + +[[package]] +name = "genawaiter-macro" +version = "0.99.1" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "0b32dfe1fdfc0bbde1f22a5da25355514b5e450c33a6af6770884c8750aedfbc" + +[[package]] +name = "genawaiter-proc-macro" +version = "0.99.1" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "784f84eebc366e15251c4a8c3acee82a6a6f427949776ecb88377362a9621738" +dependencies = [ + "proc-macro-error 0.4.12", + "proc-macro-hack", + "proc-macro2 1.0.50", + "quote 1.0.23", + "syn 1.0.107", +] + +[[package]] name = "generic-array" version = "0.12.4" source = "registry+https://github.com/rust-lang/crates.io-index" @@ -1546,14 +1576,40 @@ dependencies = [ [[package]] name = "proc-macro-error" +version = "0.4.12" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "18f33027081eba0a6d8aba6d1b1c3a3be58cbb12106341c2d5759fcd9b5277e7" +dependencies = [ + "proc-macro-error-attr 0.4.12", + "proc-macro2 1.0.50", + "quote 1.0.23", + "syn 1.0.107", + "version_check", +] + +[[package]] +name = "proc-macro-error" version = "1.0.4" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c" dependencies = [ - "proc-macro-error-attr", + "proc-macro-error-attr 1.0.4", + "proc-macro2 1.0.50", + "quote 1.0.23", + "syn 1.0.107", + "version_check", +] + +[[package]] +name = "proc-macro-error-attr" +version = "0.4.12" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "8a5b4b77fdb63c1eca72173d68d24501c54ab1269409f6b672c85deb18af69de" +dependencies = [ "proc-macro2 1.0.50", "quote 1.0.23", "syn 1.0.107", + "syn-mid", "version_check", ] @@ -1569,6 +1625,12 @@ dependencies = [ ] [[package]] +name = "proc-macro-hack" +version = "0.5.20+deprecated" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "dc375e1527247fe1a97d8b7156678dfe7c1af2fc075c9a4db3690ecd2a148068" + +[[package]] name = "proc-macro2" version = "0.4.30" source = "registry+https://github.com/rust-lang/crates.io-index" @@ -2184,6 +2246,17 @@ dependencies = [ ] [[package]] +name = "syn-mid" +version = "0.5.3" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "baa8e7560a164edb1621a55d18a0c59abf49d360f47aa7b821061dd7eea7fac9" +dependencies = [ + "proc-macro2 1.0.50", + "quote 1.0.23", + "syn 1.0.107", +] + +[[package]] name = "sync_wrapper" version = "0.1.2" source = "registry+https://github.com/rust-lang/crates.io-index" @@ -2247,7 +2320,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "e45b7bf6e19353ddd832745c8fcf77a17a93171df7151187f26623f2b75b5b26" dependencies = [ "cfg-if", - "proc-macro-error", + "proc-macro-error 1.0.4", "proc-macro2 1.0.50", "quote 1.0.23", "syn 1.0.107", @@ -2649,6 +2722,7 @@ dependencies = [ "codemap-diagnostic", "criterion", "dirs", + "genawaiter", "imbl", "itertools", "lazy_static", diff --git a/tvix/Cargo.nix b/tvix/Cargo.nix index 9f172e1b9e..126edecdff 100644 --- a/tvix/Cargo.nix +++ b/tvix/Cargo.nix @@ -1118,7 +1118,7 @@ rec { } { name = "proc-macro-error"; - packageId = "proc-macro-error"; + packageId = "proc-macro-error 1.0.4"; } { name = "proc-macro2"; @@ -2308,6 +2308,85 @@ rec { ]; }; + "genawaiter" = rec { + crateName = "genawaiter"; + version = "0.99.1"; + edition = "2018"; + sha256 = "1861a6vy9lc9a8lbw496m9j9jcjcn9nf7rkm6jqkkpnb3cvd0sy8"; + authors = [ + "John Simon <john@whatisaph.one>" + ]; + dependencies = [ + { + name = "genawaiter-macro"; + packageId = "genawaiter-macro"; + } + { + name = "genawaiter-proc-macro"; + packageId = "genawaiter-proc-macro"; + optional = true; + } + { + name = "proc-macro-hack"; + packageId = "proc-macro-hack"; + optional = true; + } + ]; + features = { + "default" = [ "proc_macro" ]; + "futures-core" = [ "dep:futures-core" ]; + "futures03" = [ "futures-core" ]; + "genawaiter-proc-macro" = [ "dep:genawaiter-proc-macro" ]; + "proc-macro-hack" = [ "dep:proc-macro-hack" ]; + "proc_macro" = [ "genawaiter-proc-macro" "proc-macro-hack" "genawaiter-macro/proc_macro" ]; + }; + resolvedDefaultFeatures = [ "default" "genawaiter-proc-macro" "proc-macro-hack" "proc_macro" ]; + }; + "genawaiter-macro" = rec { + crateName = "genawaiter-macro"; + version = "0.99.1"; + edition = "2018"; + sha256 = "1g6zmr88fk48f1ksz9ik1i2mwjsiam9s4p9aybhvs2zwzphxychb"; + authors = [ + "Devin R <devin.ragotzy@gmail.com>" + ]; + features = { }; + resolvedDefaultFeatures = [ "proc_macro" ]; + }; + "genawaiter-proc-macro" = rec { + crateName = "genawaiter-proc-macro"; + version = "0.99.1"; + edition = "2018"; + sha256 = "0f0pcaln4wrpi35nwxs9g516ysiax373m32a3hjiavinpkp88kvq"; + procMacro = true; + authors = [ + "Devin R <devin.ragotzy@gmail.com>" + ]; + dependencies = [ + { + name = "proc-macro-error"; + packageId = "proc-macro-error 0.4.12"; + } + { + name = "proc-macro-hack"; + packageId = "proc-macro-hack"; + } + { + name = "proc-macro2"; + packageId = "proc-macro2 1.0.50"; + } + { + name = "quote"; + packageId = "quote 1.0.23"; + } + { + name = "syn"; + packageId = "syn 1.0.107"; + features = [ "visit-mut" "full" ]; + } + ]; + features = { }; + }; "generic-array 0.12.4" = rec { crateName = "generic-array"; version = "0.12.4"; @@ -4357,7 +4436,43 @@ rec { "verbatim" = [ "syn/parsing" ]; }; }; - "proc-macro-error" = rec { + "proc-macro-error 0.4.12" = rec { + crateName = "proc-macro-error"; + version = "0.4.12"; + edition = "2018"; + sha256 = "1rvpaadwv7vmsp142qqh2axqrr9v78f1nvdsi9nhmfhy10kk1wqq"; + authors = [ + "CreepySkeleton <creepy-skeleton@yandex.ru>" + ]; + dependencies = [ + { + name = "proc-macro-error-attr"; + packageId = "proc-macro-error-attr 0.4.12"; + } + { + name = "proc-macro2"; + packageId = "proc-macro2 1.0.50"; + } + { + name = "quote"; + packageId = "quote 1.0.23"; + } + { + name = "syn"; + packageId = "syn 1.0.107"; + usesDefaultFeatures = false; + features = [ "derive" "parsing" "proc-macro" "printing" ]; + } + ]; + buildDependencies = [ + { + name = "version_check"; + packageId = "version_check"; + } + ]; + + }; + "proc-macro-error 1.0.4" = rec { crateName = "proc-macro-error"; version = "1.0.4"; edition = "2018"; @@ -4368,7 +4483,7 @@ rec { dependencies = [ { name = "proc-macro-error-attr"; - packageId = "proc-macro-error-attr"; + packageId = "proc-macro-error-attr 1.0.4"; } { name = "proc-macro2"; @@ -4398,7 +4513,44 @@ rec { }; resolvedDefaultFeatures = [ "default" "syn" "syn-error" ]; }; - "proc-macro-error-attr" = rec { + "proc-macro-error-attr 0.4.12" = rec { + crateName = "proc-macro-error-attr"; + version = "0.4.12"; + edition = "2018"; + sha256 = "1pk9mwcfnpf8favgc2cl4sqlmi818p96hg8pfb51wg5nzmvlnnwa"; + procMacro = true; + authors = [ + "CreepySkeleton <creepy-skeleton@yandex.ru>" + ]; + dependencies = [ + { + name = "proc-macro2"; + packageId = "proc-macro2 1.0.50"; + } + { + name = "quote"; + packageId = "quote 1.0.23"; + } + { + name = "syn"; + packageId = "syn 1.0.107"; + usesDefaultFeatures = false; + features = [ "derive" "parsing" "proc-macro" "printing" ]; + } + { + name = "syn-mid"; + packageId = "syn-mid"; + } + ]; + buildDependencies = [ + { + name = "version_check"; + packageId = "version_check"; + } + ]; + + }; + "proc-macro-error-attr 1.0.4" = rec { crateName = "proc-macro-error-attr"; version = "1.0.4"; edition = "2018"; @@ -4425,6 +4577,17 @@ rec { ]; }; + "proc-macro-hack" = rec { + crateName = "proc-macro-hack"; + version = "0.5.20+deprecated"; + edition = "2018"; + sha256 = "0s402hmcs3k9nd6rlp07zkr1lz7yimkmcwcbgnly2zr44wamwdyw"; + procMacro = true; + authors = [ + "David Tolnay <dtolnay@gmail.com>" + ]; + + }; "proc-macro2 0.4.30" = rec { crateName = "proc-macro2"; version = "0.4.30"; @@ -6247,6 +6410,36 @@ rec { }; resolvedDefaultFeatures = [ "clone-impls" "default" "derive" "extra-traits" "full" "parsing" "printing" "proc-macro" "quote" "visit" "visit-mut" ]; }; + "syn-mid" = rec { + crateName = "syn-mid"; + version = "0.5.3"; + edition = "2018"; + sha256 = "1jgslzpdf78646wafyplc39lkgwsqnh1hpd544bdnkhn19bfga5s"; + authors = [ + "Taiki Endo <te316e89@gmail.com>" + ]; + dependencies = [ + { + name = "proc-macro2"; + packageId = "proc-macro2 1.0.50"; + usesDefaultFeatures = false; + } + { + name = "quote"; + packageId = "quote 1.0.23"; + usesDefaultFeatures = false; + } + { + name = "syn"; + packageId = "syn 1.0.107"; + usesDefaultFeatures = false; + features = [ "parsing" "printing" "derive" ]; + } + ]; + features = { + "clone-impls" = [ "syn/clone-impls" ]; + }; + }; "sync_wrapper" = rec { crateName = "sync_wrapper"; version = "0.1.2"; @@ -6401,7 +6594,7 @@ rec { } { name = "proc-macro-error"; - packageId = "proc-macro-error"; + packageId = "proc-macro-error 1.0.4"; } { name = "proc-macro2"; @@ -7858,6 +8051,10 @@ rec { packageId = "dirs"; } { + name = "genawaiter"; + packageId = "genawaiter"; + } + { name = "imbl"; packageId = "imbl"; features = [ "serde" ]; diff --git a/tvix/eval/Cargo.toml b/tvix/eval/Cargo.toml index cf46d4bbd4..6bb68834ab 100644 --- a/tvix/eval/Cargo.toml +++ b/tvix/eval/Cargo.toml @@ -14,6 +14,7 @@ builtin-macros = { path = "./builtin-macros", package = "tvix-eval-builtin-macro codemap = "0.1.3" codemap-diagnostic = "0.1.1" dirs = "4.0.0" +genawaiter = "0.99.1" imbl = { version = "2.0", features = [ "serde" ] } lazy_static = "1.4.0" lexical-core = { version = "0.8.5", features = ["format", "parse-floats"] } diff --git a/tvix/eval/src/value/mod.rs b/tvix/eval/src/value/mod.rs index ede93e7ddd..07ce830206 100644 --- a/tvix/eval/src/value/mod.rs +++ b/tvix/eval/src/value/mod.rs @@ -32,7 +32,7 @@ pub use path::canon_path; pub use string::NixString; pub use thunk::Thunk; -use self::thunk::ThunkSet; +pub use self::thunk::{SharedThunkSet, ThunkSet}; use lazy_static::lazy_static; diff --git a/tvix/eval/src/vm.rs b/tvix/eval/src/vm.rs index 10966aca81..3e30525556 100644 --- a/tvix/eval/src/vm.rs +++ b/tvix/eval/src/vm.rs @@ -1,6 +1,8 @@ //! This module implements the virtual (or abstract) machine that runs //! Tvix bytecode. +pub mod generators; + use serde_json::json; use std::{cmp::Ordering, collections::HashMap, ops::DerefMut, path::PathBuf, rc::Rc}; diff --git a/tvix/eval/src/vm/generators.rs b/tvix/eval/src/vm/generators.rs new file mode 100644 index 0000000000..3b822b0863 --- /dev/null +++ b/tvix/eval/src/vm/generators.rs @@ -0,0 +1,538 @@ +//! This module implements generator logic for the VM. Generators are functions +//! used during evaluation which can suspend their execution during their +//! control flow, and request that the VM do something. +//! +//! This is used to keep the VM's stack size constant even when evaluating +//! deeply nested recursive data structures. +//! +//! We implement generators using the [`genawaiter`] crate. + +use core::pin::Pin; +use genawaiter::rc::Co; +pub use genawaiter::rc::Gen; +use smol_str::SmolStr; +use std::fmt::Display; +use std::future::Future; + +use crate::value::SharedThunkSet; +use crate::warnings::WarningKind; +use crate::FileType; +use crate::NixString; + +use super::*; + +/// Dummy type, before the actual implementation is in place. +#[derive(Debug)] +pub struct PointerEquality {} + +// -- Implementation of generic generator logic. + +/// States that a generator can be in while being driven by the VM. +pub(crate) enum GeneratorState { + /// Normal execution of the generator. + Running, + + /// Generator is awaiting the result of a forced value. + AwaitingValue, +} + +/// Messages that can be sent from generators to the VM. In most +/// cases, the VM will suspend the generator when receiving a message +/// and enter some other frame to process the request. +/// +/// Responses are returned to generators via the [`GeneratorResponse`] type. +pub enum GeneratorRequest { + /// Request that the VM forces this value. This message is first sent to the + /// VM with the unforced value, then returned to the generator with the + /// forced result. + ForceValue(Value), + + /// Request that the VM deep-forces the value. + DeepForceValue(Value, SharedThunkSet), + + /// Request the value at the given index from the VM's with-stack, in forced + /// state. + /// + /// The value is returned in the `ForceValue` message. + WithValue(usize), + + /// Request the value at the given index from the *captured* with-stack, in + /// forced state. + CapturedWithValue(usize), + + /// Request that the two values be compared for Nix equality. The result is + /// returned in the `ForceValue` message. + NixEquality(Box<(Value, Value)>, PointerEquality), + + /// Push the given value to the VM's stack. This is used to prepare the + /// stack for requesting a function call from the VM. + /// + /// The VM does not respond to this request, so the next message received is + /// a `NoOp`. + StackPush(Value), + + /// Pop a value from the stack and return it to the generator. + StackPop, + + /// Request that the VM coerces this value to a string. + StringCoerce(Value, CoercionKind), + + /// Request that the VM calls the given value, with arguments already + /// prepared on the stack. Value must already be forced. + Call(Value), + + /// Request a call frame entering the given lambda immediately. This can be + /// used to force thunks. + EnterLambda { + lambda: Rc<Lambda>, + upvalues: Rc<Upvalues>, + light_span: LightSpan, + }, + + /// Emit a runtime warning through the VM. Receives a NoOp-response. + EmitWarning(WarningKind), + + /// Request a lookup in the VM's import cache, which tracks the + /// thunks yielded by previously imported files. + ImportCacheLookup(PathBuf), + + /// Provide the VM with an imported value for a given path, which + /// it can populate its input cache with. + ImportCachePut(PathBuf, Value), + + /// Request that the VM imports the given path through its I/O interface. + PathImport(PathBuf), + + /// Request that the VM reads the given path to a string. + ReadToString(PathBuf), + + /// Request that the VM checks whether the given path exists. + PathExists(PathBuf), + + /// Request that the VM reads the given path. + ReadDir(PathBuf), + + /// Request a reasonable span from the VM. + Span, + + /// Request evaluation of `builtins.tryEval` from the VM. See + /// [`VM::catch_result`] for an explanation of how this works. + TryForce(Value), +} + +/// Human-readable representation of a generator message, used by observers. +impl Display for GeneratorRequest { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + match self { + GeneratorRequest::ForceValue(v) => write!(f, "force_value({})", v), + GeneratorRequest::DeepForceValue(v, _) => write!(f, "deep_force_value({})", v), + GeneratorRequest::WithValue(_) => write!(f, "with_value"), + GeneratorRequest::CapturedWithValue(_) => write!(f, "captured_with_value"), + GeneratorRequest::NixEquality(values, ptr_eq) => { + write!( + f, + "nix_eq({}, {}, PointerEquality::{:?})", + values.0, values.1, ptr_eq + ) + } + GeneratorRequest::StackPush(v) => write!(f, "stack_push({})", v), + GeneratorRequest::StackPop => write!(f, "stack_pop"), + GeneratorRequest::StringCoerce(v, kind) => match kind { + CoercionKind::Weak => write!(f, "weak_string_coerce({})", v), + CoercionKind::Strong => write!(f, "strong_string_coerce({})", v), + CoercionKind::ThunksOnly => todo!("remove this branch (not live)"), + }, + GeneratorRequest::Call(v) => write!(f, "call({})", v), + GeneratorRequest::EnterLambda { lambda, .. } => { + write!(f, "enter_lambda({:p})", *lambda) + } + GeneratorRequest::EmitWarning(_) => write!(f, "emit_warning"), + GeneratorRequest::ImportCacheLookup(p) => { + write!(f, "import_cache_lookup({})", p.to_string_lossy()) + } + GeneratorRequest::ImportCachePut(p, _) => { + write!(f, "import_cache_put({})", p.to_string_lossy()) + } + GeneratorRequest::PathImport(p) => write!(f, "path_import({})", p.to_string_lossy()), + GeneratorRequest::ReadToString(p) => { + write!(f, "read_to_string({})", p.to_string_lossy()) + } + GeneratorRequest::PathExists(p) => write!(f, "path_exists({})", p.to_string_lossy()), + GeneratorRequest::ReadDir(p) => write!(f, "read_dir({})", p.to_string_lossy()), + GeneratorRequest::Span => write!(f, "span"), + GeneratorRequest::TryForce(v) => write!(f, "try_force({})", v), + } + } +} + +/// Responses returned to generators from the VM. +pub enum GeneratorResponse { + /// Empty message. Passed to the generator as the first message, + /// or when return values were optional. + Empty, + + /// Value produced by the VM and returned to the generator. + Value(Value), + + /// Path produced by the VM in response to some IO operation. + Path(PathBuf), + + /// VM response with the contents of a directory. + Directory(Vec<(SmolStr, FileType)>), + + /// VM response with a span to use at the current point. + Span(LightSpan), + + /// Message returned by the VM when a catchable error is encountered during + /// the evaluation of `builtins.tryEval`. + ForceError, +} + +impl Display for GeneratorResponse { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + match self { + GeneratorResponse::Empty => write!(f, "empty"), + GeneratorResponse::Value(v) => write!(f, "value({})", v), + GeneratorResponse::Path(p) => write!(f, "path({})", p.to_string_lossy()), + GeneratorResponse::Directory(d) => write!(f, "dir(len = {})", d.len()), + GeneratorResponse::Span(_) => write!(f, "span"), + GeneratorResponse::ForceError => write!(f, "force_error"), + } + } +} + +pub(crate) type Generator = Gen< + GeneratorRequest, + GeneratorResponse, + Pin<Box<dyn Future<Output = Result<Value, ErrorKind>>>>, +>; + +/// Helper function to provide type annotations which are otherwise difficult to +/// infer. +pub fn pin_generator( + f: impl Future<Output = Result<Value, ErrorKind>> + 'static, +) -> Pin<Box<dyn Future<Output = Result<Value, ErrorKind>>>> { + Box::pin(f) +} + +pub type GenCo = Co<GeneratorRequest, GeneratorResponse>; + +// -- Implementation of concrete generator use-cases. + +/// Request that the VM place the given value on its stack. +pub async fn request_stack_push(co: &GenCo, val: Value) { + match co.yield_(GeneratorRequest::StackPush(val)).await { + GeneratorResponse::Empty => {} + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +/// Request that the VM pop a value from the stack and return it to the +/// generator. +pub async fn request_stack_pop(co: &GenCo) -> Value { + match co.yield_(GeneratorRequest::StackPop).await { + GeneratorResponse::Value(value) => value, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +/// Force any value and return the evaluated result from the VM. +pub async fn request_force(co: &GenCo, val: Value) -> Value { + if let Value::Thunk(_) = val { + match co.yield_(GeneratorRequest::ForceValue(val)).await { + GeneratorResponse::Value(value) => value, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } + } else { + val + } +} + +/// Force a value, but inform the caller (by returning `None`) if a catchable +/// error occured. +pub(crate) async fn request_try_force(co: &GenCo, val: Value) -> Option<Value> { + if let Value::Thunk(_) = val { + match co.yield_(GeneratorRequest::TryForce(val)).await { + GeneratorResponse::Value(value) => Some(value), + GeneratorResponse::ForceError => None, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } + } else { + Some(val) + } +} + +/// Call the given value as a callable. The argument(s) must already be prepared +/// on the stack. +pub async fn request_call(co: &GenCo, val: Value) -> Value { + let val = request_force(co, val).await; + match co.yield_(GeneratorRequest::Call(val)).await { + GeneratorResponse::Value(value) => value, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +/// Helper function to call the given value with the provided list of arguments. +/// This uses the StackPush and Call messages under the hood. +pub async fn request_call_with<I>(co: &GenCo, mut callable: Value, args: I) -> Value +where + I: IntoIterator<Item = Value>, + I::IntoIter: DoubleEndedIterator, +{ + let mut num_args = 0_usize; + for arg in args.into_iter().rev() { + num_args += 1; + request_stack_push(co, arg).await; + } + + debug_assert!(num_args > 0, "call_with called with an empty list of args"); + + while num_args > 0 { + callable = request_call(co, callable).await; + num_args -= 1; + } + + callable +} + +pub async fn request_string_coerce(co: &GenCo, val: Value, kind: CoercionKind) -> NixString { + match val { + Value::String(s) => s, + _ => match co.yield_(GeneratorRequest::StringCoerce(val, kind)).await { + GeneratorResponse::Value(value) => value + .to_str() + .expect("coerce_to_string always returns a string"), + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + }, + } +} + +/// Deep-force any value and return the evaluated result from the VM. +pub async fn request_deep_force(co: &GenCo, val: Value, thunk_set: SharedThunkSet) -> Value { + match co + .yield_(GeneratorRequest::DeepForceValue(val, thunk_set)) + .await + { + GeneratorResponse::Value(value) => value, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +/// Fetch and force a value on the with-stack from the VM. +async fn fetch_forced_with(co: &GenCo, idx: usize) -> Value { + match co.yield_(GeneratorRequest::WithValue(idx)).await { + GeneratorResponse::Value(value) => value, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +/// Fetch and force a value on the *captured* with-stack from the VM. +async fn fetch_captured_with(co: &GenCo, idx: usize) -> Value { + match co.yield_(GeneratorRequest::CapturedWithValue(idx)).await { + GeneratorResponse::Value(value) => value, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +/// Ask the VM to compare two values for equality. +pub(crate) async fn check_equality( + co: &GenCo, + a: Value, + b: Value, + ptr_eq: PointerEquality, +) -> Result<bool, ErrorKind> { + match co + .yield_(GeneratorRequest::NixEquality(Box::new((a, b)), ptr_eq)) + .await + { + GeneratorResponse::Value(value) => value.as_bool(), + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +/// Emit a runtime warning. +pub(crate) async fn emit_warning(co: &GenCo, kind: WarningKind) { + match co.yield_(GeneratorRequest::EmitWarning(kind)).await { + GeneratorResponse::Empty => {} + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +/// Request that the VM enter the given lambda. +pub(crate) async fn request_enter_lambda( + co: &GenCo, + lambda: Rc<Lambda>, + upvalues: Rc<Upvalues>, + light_span: LightSpan, +) -> Value { + let msg = GeneratorRequest::EnterLambda { + lambda, + upvalues, + light_span, + }; + + match co.yield_(msg).await { + GeneratorResponse::Value(value) => value, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +/// Request a lookup in the VM's import cache. +pub(crate) async fn request_import_cache_lookup(co: &GenCo, path: PathBuf) -> Option<Value> { + match co.yield_(GeneratorRequest::ImportCacheLookup(path)).await { + GeneratorResponse::Value(value) => Some(value), + GeneratorResponse::Empty => None, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +/// Request that the VM populate its input cache for the given path. +pub(crate) async fn request_import_cache_put(co: &GenCo, path: PathBuf, value: Value) { + match co + .yield_(GeneratorRequest::ImportCachePut(path, value)) + .await + { + GeneratorResponse::Empty => {} + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +/// Request that the VM import the given path. +pub(crate) async fn request_path_import(co: &GenCo, path: PathBuf) -> PathBuf { + match co.yield_(GeneratorRequest::PathImport(path)).await { + GeneratorResponse::Path(path) => path, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +pub(crate) async fn request_read_to_string(co: &GenCo, path: PathBuf) -> Value { + match co.yield_(GeneratorRequest::ReadToString(path)).await { + GeneratorResponse::Value(value) => value, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +pub(crate) async fn request_path_exists(co: &GenCo, path: PathBuf) -> Value { + match co.yield_(GeneratorRequest::PathExists(path)).await { + GeneratorResponse::Value(value) => value, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +pub(crate) async fn request_read_dir(co: &GenCo, path: PathBuf) -> Vec<(SmolStr, FileType)> { + match co.yield_(GeneratorRequest::ReadDir(path)).await { + GeneratorResponse::Directory(dir) => dir, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +pub(crate) async fn request_span(co: &GenCo) -> LightSpan { + match co.yield_(GeneratorRequest::Span).await { + GeneratorResponse::Span(span) => span, + msg => panic!( + "Tvix bug: VM responded with incorrect generator message: {}", + msg + ), + } +} + +pub(crate) async fn neo_resolve_with( + co: GenCo, + ident: String, + vm_with_len: usize, + upvalue_with_len: usize, +) -> Result<Value, ErrorKind> { + for with_stack_idx in (0..vm_with_len).rev() { + // TODO(tazjin): is this branch still live with the current with-thunking? + let with = fetch_forced_with(&co, with_stack_idx).await; + + match with.to_attrs()?.select(&ident) { + None => continue, + Some(val) => return Ok(val.clone()), + } + } + + for upvalue_with_idx in (0..upvalue_with_len).rev() { + let with = fetch_captured_with(&co, upvalue_with_idx).await; + + match with.to_attrs()?.select(&ident) { + None => continue, + Some(val) => return Ok(val.clone()), + } + } + + Err(ErrorKind::UnknownDynamicVariable(ident)) +} + +/// Call the given value as if it was an attribute set containing a functor. The +/// arguments must already be prepared on the stack when a generator frame from +/// this function is invoked. +/// +pub(crate) async fn call_functor(co: GenCo, value: Value) -> Result<Value, ErrorKind> { + let attrs = value.to_attrs()?; + + match attrs.select("__functor") { + None => Err(ErrorKind::NotCallable("set without `__functor_` attribute")), + Some(functor) => { + // The functor receives the set itself as its first argument and + // needs to be called with it. + let functor = request_force(&co, functor.clone()).await; + let primed = request_call_with(&co, functor, [value]).await; + Ok(request_call(&co, primed).await) + } + } +} |