diff options
5 files changed, 133 insertions, 13 deletions
diff --git a/tvix/eval/src/compiler/bindings.rs b/tvix/eval/src/compiler/bindings.rs index 53344d067771..5f4d1c4d0b3a 100644 --- a/tvix/eval/src/compiler/bindings.rs +++ b/tvix/eval/src/compiler/bindings.rs @@ -4,7 +4,7 @@ //! In the case of recursive scopes these cases share almost all of their //! (fairly complex) logic. -use rnix::ast::AttrpathValue; +use rnix::ast::{AttrpathValue, HasEntry}; use super::*; @@ -27,6 +27,29 @@ impl BindingsKind { } } +// Internal representation of an attribute set used for merging sets, or +// inserting nested keys. +#[derive(Clone)] +struct AttributeSet { + /// Original span at which this set was first encountered. + span: Span, + + /// Tracks the kind of set (rec or not). + kind: BindingsKind, + + /// All inherited entries + inherits: Vec<ast::Inherit>, + + /// All internal entries + entries: Vec<ast::AttrpathValue>, +} + +impl ToSpan for AttributeSet { + fn span_for(&self, _: &codemap::File) -> Span { + self.span + } +} + // Data structures to track the bindings observed in the second pass, and // forward the information needed to compile their value. enum Binding { @@ -39,19 +62,60 @@ enum Binding { Plain { expr: ast::Expr, }, + + Set(AttributeSet), } impl Binding { - fn merge(&mut self, _expr: ast::Expr) -> Option<ErrorKind> { + fn merge(&mut self, c: &mut Compiler, expr: ast::Expr) { match self { - Binding::InheritFrom { name, .. } => { - Some(ErrorKind::UnmergeableInherit { name: name.clone() }) + Binding::InheritFrom { name, ref span, .. } => { + c.emit_error(span, ErrorKind::UnmergeableInherit { name: name.clone() }) } - Binding::Plain { expr } => match expr { - ast::Expr::AttrSet(_) => todo!(), - _ => Some(ErrorKind::UnmergeableValue), + Binding::Plain { expr: existing } => match existing { + ast::Expr::AttrSet(existing) => { + if let ast::Expr::AttrSet(new) = expr { + let merged = AttributeSet { + span: c.span_for(existing), + + // Kind of the attrs depends on the first time it is + // encountered. We actually believe this to be a Nix + // bug: https://github.com/NixOS/nix/issues/7111 + kind: if existing.rec_token().is_some() { + BindingsKind::RecAttrs + } else { + BindingsKind::Attrs + }, + + inherits: ast::HasEntry::inherits(existing) + .chain(ast::HasEntry::inherits(&new)) + .collect(), + + entries: ast::HasEntry::attrpath_values(existing) + .chain(ast::HasEntry::attrpath_values(&new)) + .collect(), + }; + + *self = Binding::Set(merged); + } else { + todo!() + } + } + + _ => c.emit_error(&expr, ErrorKind::UnmergeableValue), }, + + Binding::Set(existing) => { + if let ast::Expr::AttrSet(new) = expr { + existing.inherits.extend(ast::HasEntry::inherits(&new)); + existing + .entries + .extend(ast::HasEntry::attrpath_values(&new)); + } else { + todo!() + } + } } } } @@ -133,9 +197,7 @@ impl TrackedBindings { }; // No more excuses ... the binding can be merged! - if let Some(err) = binding.binding.merge(value) { - c.emit_error(entry, err); - } + binding.binding.merge(c, value); true } @@ -150,6 +212,33 @@ impl TrackedBindings { } } +/// Wrapper around the `ast::HasEntry` trait as that trait can not be +/// implemented for custom types. +trait HasEntryProxy { + fn inherits(&self) -> Box<dyn Iterator<Item = ast::Inherit>>; + fn attrpath_values(&self) -> Box<dyn Iterator<Item = ast::AttrpathValue>>; +} + +impl<N: HasEntry> HasEntryProxy for N { + fn inherits(&self) -> Box<dyn Iterator<Item = ast::Inherit>> { + Box::new(ast::HasEntry::inherits(self)) + } + + fn attrpath_values(&self) -> Box<dyn Iterator<Item = ast::AttrpathValue>> { + Box::new(ast::HasEntry::attrpath_values(self)) + } +} + +impl HasEntryProxy for AttributeSet { + fn inherits(&self) -> Box<dyn Iterator<Item = ast::Inherit>> { + Box::new(self.inherits.clone().into_iter()) + } + + fn attrpath_values(&self) -> Box<dyn Iterator<Item = ast::AttrpathValue>> { + Box::new(self.entries.clone().into_iter()) + } +} + /// AST-traversing functions related to bindings. impl Compiler<'_> { /// Compile all inherits of a node with entries that do *not* have a @@ -162,7 +251,7 @@ impl Compiler<'_> { node: &N, ) -> Vec<(ast::Expr, SmolStr, Span)> where - N: ToSpan + ast::HasEntry, + N: ToSpan + HasEntryProxy, { // Pass over all inherits, resolving only those without namespaces. // Since they always resolve in a higher scope, we can just compile and @@ -309,7 +398,7 @@ impl Compiler<'_> { bindings: &mut TrackedBindings, node: &N, ) where - N: ToSpan + ast::HasEntry, + N: ToSpan + HasEntryProxy, { for entry in node.attrpath_values() { if bindings.try_merge(self, &entry) { @@ -450,6 +539,14 @@ impl Compiler<'_> { // Binding is "just" a plain expression that needs to be // compiled. Binding::Plain { expr } => self.compile(binding.value_slot, expr), + + // Binding is a merged or nested attribute set, and needs to be + // recursively compiled as another binding. + Binding::Set(set) => self.thunk(binding.value_slot, &set, |c, n, s| { + c.scope_mut().begin_scope(); + c.compile_bindings(binding.value_slot, set.kind, &set); + c.scope_mut().end_scope(); + }), } // Any code after this point will observe the value in the right @@ -469,7 +566,7 @@ impl Compiler<'_> { fn compile_bindings<N>(&mut self, slot: LocalIdx, kind: BindingsKind, node: &N) where - N: ToSpan + ast::HasEntry, + N: ToSpan + HasEntryProxy, { let mut count = 0; self.scope_mut().begin_scope(); diff --git a/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-attrs.exp b/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-attrs.exp new file mode 100644 index 000000000000..911ab51de5ca --- /dev/null +++ b/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-attrs.exp @@ -0,0 +1 @@ +{ set = { a = 1; b = 2; }; } diff --git a/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-attrs.nix b/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-attrs.nix new file mode 100644 index 000000000000..78b28909a29c --- /dev/null +++ b/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-attrs.nix @@ -0,0 +1,9 @@ +{ + set = { + a = 1; + }; + + set = { + b = 2; + }; +} diff --git a/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-rec-attrs.exp b/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-rec-attrs.exp new file mode 100644 index 000000000000..768eaae61cfc --- /dev/null +++ b/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-rec-attrs.exp @@ -0,0 +1 @@ +{ set = { a = 21; b = 42; }; } diff --git a/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-rec-attrs.nix b/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-rec-attrs.nix new file mode 100644 index 000000000000..cea4cb1b4f0d --- /dev/null +++ b/tvix/eval/src/tests/tvix_tests/eval-okay-merge-nested-rec-attrs.nix @@ -0,0 +1,12 @@ +{ + set = rec { + a = 21; + }; + + set = { + # Fun fact: This might be the only case in Nix where a lexical + # resolution of an identifier can only be resolved by looking at + # *siblings* in the AST. + b = 2 * a; + }; +} |