fatou 0.22.0

A language server, formatter, and linter for Julia
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//! The per-file soundness scan the resolution-dependent rules share.
//!
//! Julia's `include`-splicing and metaprogramming make "what does this name
//! mean?" undecidable for a file in isolation. Every rule that asks the
//! [`Resolver`](crate::resolve::Resolver) a question first has to know whether
//! the file is answerable at all, and which spans inside it are trustworthy.
//! One pass over the CST collects both: the `eval`/`include` shapes that bail
//! the whole file, and the macro-call and quote extents that exempt a span.
//!
//! Built once per file and memoized on [`RuleContext`](super::RuleContext) —
//! ask for it with [`RuleContext::file_scan`](super::RuleContext::file_scan)
//! rather than running the walk again.

use rowan::TextRange;

use crate::project::scripts::DefinitionEffects;
use crate::syntax::{SyntaxKind, SyntaxNode};

/// One pass over the CST collecting everything a resolution-dependent rule
/// skips or bails on: macro-call and quote extents, and the `eval`/`include`
/// call shapes.
pub(crate) struct FileScan {
    /// `MACRO_CALL` extents. A macro receives unevaluated expressions and may
    /// rewrite them or bind names itself, so what is written inside one is not
    /// what runs. The macro's own name is still a real read.
    macro_calls: Vec<TextRange>,
    /// `QUOTE_EXPR`/`QUOTE_SYM` extents: quoted code is data, not code.
    quotes: Vec<TextRange>,
    /// The file calls `eval`/`@eval`, which can define anything at runtime.
    pub(crate) calls_eval: bool,
    /// The file `include`s a literal path. The harvest follows those, so they
    /// are only a problem without a workspace to have harvested them.
    pub(crate) literal_include: bool,
    /// The file `include`s a computed path, which no harvest can follow.
    pub(crate) dynamic_include: bool,
}

impl FileScan {
    pub(crate) fn collect(root: &SyntaxNode) -> Self {
        let mut scan = FileScan {
            macro_calls: Vec::new(),
            quotes: Vec::new(),
            calls_eval: false,
            literal_include: false,
            dynamic_include: false,
        };
        let mut effects = DefinitionEffects::default();
        for node in root.descendants() {
            effects.observe(&node);
            match node.kind() {
                SyntaxKind::MACRO_CALL => scan.macro_calls.push(node.text_range()),
                SyntaxKind::QUOTE_EXPR | SyntaxKind::QUOTE_SYM => {
                    scan.quotes.push(node.text_range())
                }
                _ => {}
            }
        }
        scan.calls_eval = effects.calls_eval;
        scan.literal_include = effects.literal_include;
        scan.dynamic_include = effects.dynamic_include;
        scan
    }

    /// Whether `range` sits inside quoted code (`:(…)`, `:sym`, `quote … end`).
    pub(crate) fn in_quote(&self, range: TextRange) -> bool {
        within(&self.quotes, range)
    }

    /// Whether `range` sits inside a macro call's extent, the macro's own name
    /// included.
    pub(crate) fn in_macro_call(&self, range: TextRange) -> bool {
        within(&self.macro_calls, range)
    }

    /// Whether the code at `range` is exempt outright: quoted, or inside a
    /// macro call. The composition every rule reasoning about *code* wants;
    /// `undefined-name`, which reasons about individual *reads*, keeps the
    /// macro's own name in scope and so composes the two halves itself.
    pub(crate) fn in_skipped(&self, range: TextRange) -> bool {
        self.in_quote(range) || self.in_macro_call(range)
    }
}

fn within(extents: &[TextRange], range: TextRange) -> bool {
    extents.iter().any(|e| e.contains_range(range))
}