dfir_lang/graph/
mod.rs

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1//! Graph representation stages for DFIR graphs.
2
3use std::borrow::Cow;
4use std::hash::Hash;
5
6use proc_macro2::{Ident, Span, TokenStream};
7use quote::ToTokens;
8use serde::{Deserialize, Serialize};
9use slotmap::new_key_type;
10use syn::punctuated::Punctuated;
11use syn::spanned::Spanned;
12use syn::{Expr, ExprPath, GenericArgument, Token, Type};
13
14use self::ops::{OperatorConstraints, Persistence};
15use crate::diagnostic::{Diagnostic, Level};
16use crate::parse::{DfirCode, IndexInt, Operator, PortIndex, Ported};
17use crate::pretty_span::PrettySpan;
18
19mod di_mul_graph;
20mod eliminate_extra_unions_tees;
21mod flat_graph_builder;
22mod flat_to_partitioned;
23mod graph_write;
24mod meta_graph;
25mod meta_graph_debugging;
26
27use std::fmt::Display;
28
29pub use di_mul_graph::DiMulGraph;
30pub use eliminate_extra_unions_tees::eliminate_extra_unions_tees;
31pub use flat_graph_builder::FlatGraphBuilder;
32pub use flat_to_partitioned::partition_graph;
33pub use meta_graph::{DfirGraph, WriteConfig, WriteGraphType};
34
35pub mod graph_algorithms;
36pub mod ops;
37
38new_key_type! {
39    /// ID to identify a node (operator or handoff) in [`DfirGraph`].
40    pub struct GraphNodeId;
41
42    /// ID to identify an edge.
43    pub struct GraphEdgeId;
44
45    /// ID to identify a subgraph in [`DfirGraph`].
46    pub struct GraphSubgraphId;
47
48    /// ID to identify a loop block in [`DfirGraph`].
49    pub struct GraphLoopId;
50}
51
52impl GraphSubgraphId {
53    /// Generate a deterministic `Ident` for the given loop ID.
54    pub fn as_ident(self, span: Span) -> Ident {
55        use slotmap::Key;
56        Ident::new(&format!("sgid_{:?}", self.data()), span)
57    }
58}
59
60impl GraphLoopId {
61    /// Generate a deterministic `Ident` for the given loop ID.
62    pub fn as_ident(self, span: Span) -> Ident {
63        use slotmap::Key;
64        Ident::new(&format!("loop_{:?}", self.data()), span)
65    }
66}
67
68/// Context identifier as a string.
69const CONTEXT: &str = "context";
70/// Runnable DFIR graph object identifier as a string.
71const GRAPH: &str = "df";
72
73const HANDOFF_NODE_STR: &str = "handoff";
74const MODULE_BOUNDARY_NODE_STR: &str = "module_boundary";
75
76mod serde_syn {
77    use serde::{Deserialize, Deserializer, Serializer};
78
79    pub fn serialize<S, T>(value: &T, serializer: S) -> Result<S::Ok, S::Error>
80    where
81        S: Serializer,
82        T: quote::ToTokens,
83    {
84        serializer.serialize_str(&value.to_token_stream().to_string())
85    }
86
87    pub fn deserialize<'de, D, T>(deserializer: D) -> Result<T, D::Error>
88    where
89        D: Deserializer<'de>,
90        T: syn::parse::Parse,
91    {
92        let s = String::deserialize(deserializer)?;
93        syn::parse_str(&s).map_err(<D::Error as serde::de::Error>::custom)
94    }
95}
96
97#[derive(Clone, Debug, Serialize, Deserialize, PartialOrd, Ord, PartialEq, Eq)]
98struct Varname(#[serde(with = "serde_syn")] pub Ident);
99
100/// A node, corresponding to an operator or a handoff.
101#[derive(Clone, Serialize, Deserialize)]
102pub enum GraphNode {
103    /// An operator.
104    Operator(#[serde(with = "serde_syn")] Operator),
105    /// A handoff point, used between subgraphs (or within a subgraph to break a cycle).
106    Handoff {
107        /// The span of the input into the handoff.
108        #[serde(skip, default = "Span::call_site")]
109        src_span: Span,
110        /// The span of the output out of the handoff.
111        #[serde(skip, default = "Span::call_site")]
112        dst_span: Span,
113    },
114
115    /// Module Boundary, used for importing modules. Only exists prior to partitioning.
116    ModuleBoundary {
117        /// If this module is an input or output boundary.
118        input: bool,
119
120        /// The span of the import!() expression that imported this module.
121        /// The value of this span when the ModuleBoundary node is still inside the module is Span::call_site()
122        /// TODO: This could one day reference into the module file itself?
123        #[serde(skip, default = "Span::call_site")]
124        import_expr: Span,
125    },
126}
127impl GraphNode {
128    /// Return the node as a human-readable string.
129    pub fn to_pretty_string(&self) -> Cow<'static, str> {
130        match self {
131            GraphNode::Operator(op) => op.to_pretty_string().into(),
132            GraphNode::Handoff { .. } => HANDOFF_NODE_STR.into(),
133            GraphNode::ModuleBoundary { .. } => MODULE_BOUNDARY_NODE_STR.into(),
134        }
135    }
136
137    /// Return the name of the node as a string, excluding parenthesis and op source code.
138    pub fn to_name_string(&self) -> Cow<'static, str> {
139        match self {
140            GraphNode::Operator(op) => op.name_string().into(),
141            GraphNode::Handoff { .. } => HANDOFF_NODE_STR.into(),
142            GraphNode::ModuleBoundary { .. } => MODULE_BOUNDARY_NODE_STR.into(),
143        }
144    }
145
146    /// Return the source code span of the node (for operators) or input/otput spans for handoffs.
147    pub fn span(&self) -> Span {
148        match self {
149            Self::Operator(op) => op.span(),
150            &Self::Handoff {
151                src_span, dst_span, ..
152            } => src_span.join(dst_span).unwrap_or(src_span),
153            Self::ModuleBoundary { import_expr, .. } => *import_expr,
154        }
155    }
156}
157impl std::fmt::Debug for GraphNode {
158    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
159        match self {
160            Self::Operator(operator) => {
161                write!(f, "Node::Operator({} span)", PrettySpan(operator.span()))
162            }
163            Self::Handoff { .. } => write!(f, "Node::Handoff"),
164            Self::ModuleBoundary { input, .. } => {
165                write!(f, "Node::ModuleBoundary{{input: {}}}", input)
166            }
167        }
168    }
169}
170
171/// Meta-data relating to operators which may be useful throughout the compilation process.
172///
173/// This data can be generated from the graph, but it is useful to have it readily available
174/// pre-computed as many algorithms use the same info. Stuff like port names, arguments, and the
175/// [`OperatorConstraints`] for the operator.
176///
177/// Because it is derived from the graph itself, there can be "cache invalidation"-esque issues
178/// if this data is not kept in sync with the graph.
179#[derive(Clone, Debug)]
180pub struct OperatorInstance {
181    /// Name of the operator (will match [`OperatorConstraints::name`]).
182    pub op_constraints: &'static OperatorConstraints,
183    /// Port values used as this operator's input.
184    pub input_ports: Vec<PortIndexValue>,
185    /// Port values used as this operator's output.
186    pub output_ports: Vec<PortIndexValue>,
187    /// Singleton references within the operator arguments.
188    pub singletons_referenced: Vec<Ident>,
189
190    /// Generic arguments.
191    pub generics: OpInstGenerics,
192    /// Arguments provided by the user into the operator as arguments.
193    /// I.e. the `a, b, c` in `-> my_op(a, b, c) -> `.
194    ///
195    /// These arguments do not include singleton postprocessing codegen. Instead use
196    /// [`ops::WriteContextArgs::arguments`].
197    pub arguments_pre: Punctuated<Expr, Token![,]>,
198    /// Unparsed arguments, for singleton parsing.
199    pub arguments_raw: TokenStream,
200}
201
202/// Operator generic arguments, split into specific categories.
203#[derive(Clone, Debug)]
204pub struct OpInstGenerics {
205    /// Operator generic (type or lifetime) arguments.
206    pub generic_args: Option<Punctuated<GenericArgument, Token![,]>>,
207    /// Lifetime persistence arguments. Corresponds to a prefix of [`Self::generic_args`].
208    pub persistence_args: Vec<Persistence>,
209    /// Type persistence arguments. Corersponds to a (suffix) of [`Self::generic_args`].
210    pub type_args: Vec<Type>,
211}
212
213/// Gets the generic arguments for the operator.
214///
215/// This helper method is useful due to the special handling of persistence lifetimes (`'static`,
216/// `'tick`, `'mutable`) which must come before other generic parameters.
217pub fn get_operator_generics(
218    diagnostics: &mut Vec<Diagnostic>,
219    operator: &Operator,
220) -> OpInstGenerics {
221    // Generic arguments.
222    let generic_args = operator.type_arguments().cloned();
223    let persistence_args = generic_args.iter().flatten().map_while(|generic_arg| match generic_arg {
224            GenericArgument::Lifetime(lifetime) => {
225                match &*lifetime.ident.to_string() {
226                    "none" => Some(Persistence::None),
227                    "loop" => Some(Persistence::Loop),
228                    "tick" => Some(Persistence::Tick),
229                    "static" => Some(Persistence::Static),
230                    "mutable" => Some(Persistence::Mutable),
231                    _ => {
232                        diagnostics.push(Diagnostic::spanned(
233                            generic_arg.span(),
234                            Level::Error,
235                            format!("Unknown lifetime generic argument `'{}`, expected `'none`, `'loop`, `'tick`, `'static`, or `'mutable`.", lifetime.ident),
236                        ));
237                        // TODO(mingwei): should really keep going and not short circuit?
238                        None
239                    }
240                }
241            },
242            _ => None,
243        }).collect::<Vec<_>>();
244    let type_args = generic_args
245        .iter()
246        .flatten()
247        .skip(persistence_args.len())
248        .map_while(|generic_arg| match generic_arg {
249            GenericArgument::Type(typ) => Some(typ),
250            _ => None,
251        })
252        .cloned()
253        .collect::<Vec<_>>();
254
255    OpInstGenerics {
256        generic_args,
257        persistence_args,
258        type_args,
259    }
260}
261
262/// Push, Pull, Comp, or Hoff polarity.
263#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
264pub enum Color {
265    /// Pull (green)
266    Pull,
267    /// Push (blue)
268    Push,
269    /// Computation (yellow)
270    Comp,
271    /// Handoff (grey) -- not a color for operators, inserted between subgraphs.
272    Hoff,
273}
274
275/// Helper struct for [`PortIndex`] which keeps span information for elided ports.
276#[derive(Clone, Debug, Serialize, Deserialize)]
277pub enum PortIndexValue {
278    /// An integer value: `[0]`, `[1]`, etc. Can be negative although we don't use that (2023-08-16).
279    Int(#[serde(with = "serde_syn")] IndexInt),
280    /// A name or path. `[pos]`, `[neg]`, etc. Can use `::` separators but we don't use that (2023-08-16).
281    Path(#[serde(with = "serde_syn")] ExprPath),
282    /// Elided, unspecified port. We have this variant, rather than wrapping in `Option`, in order
283    /// to preserve the `Span` information.
284    Elided(#[serde(skip)] Option<Span>),
285}
286impl PortIndexValue {
287    /// For a [`Ported`] value like `[port_in]name[port_out]`, get the `port_in` and `port_out` as
288    /// [`PortIndexValue`]s.
289    pub fn from_ported<Inner>(ported: Ported<Inner>) -> (Self, Inner, Self)
290    where
291        Inner: Spanned,
292    {
293        let ported_span = Some(ported.inner.span());
294        let port_inn = ported
295            .inn
296            .map(|idx| idx.index.into())
297            .unwrap_or_else(|| Self::Elided(ported_span));
298        let inner = ported.inner;
299        let port_out = ported
300            .out
301            .map(|idx| idx.index.into())
302            .unwrap_or_else(|| Self::Elided(ported_span));
303        (port_inn, inner, port_out)
304    }
305
306    /// Returns `true` if `self` is not [`PortIndexValue::Elided`].
307    pub fn is_specified(&self) -> bool {
308        !matches!(self, Self::Elided(_))
309    }
310
311    /// Returns whichever of the two ports are specified.
312    /// If both are [`Self::Elided`], returns [`Self::Elided`].
313    /// If both are specified, returns `Err(self)`.
314    #[allow(clippy::allow_attributes, reason = "Only triggered on nightly.")]
315    #[allow(
316        clippy::result_large_err,
317        reason = "variants are same size, error isn't to be propagated."
318    )]
319    pub fn combine(self, other: Self) -> Result<Self, Self> {
320        match (self.is_specified(), other.is_specified()) {
321            (false, _other) => Ok(other),
322            (true, false) => Ok(self),
323            (true, true) => Err(self),
324        }
325    }
326
327    /// Formats self as a human-readable string for error messages.
328    pub fn as_error_message_string(&self) -> String {
329        match self {
330            PortIndexValue::Int(n) => format!("`{}`", n.value),
331            PortIndexValue::Path(path) => format!("`{}`", path.to_token_stream()),
332            PortIndexValue::Elided(_) => "<elided>".to_owned(),
333        }
334    }
335
336    /// Returns the span of this port value.
337    pub fn span(&self) -> Span {
338        match self {
339            PortIndexValue::Int(x) => x.span(),
340            PortIndexValue::Path(x) => x.span(),
341            PortIndexValue::Elided(span) => span.unwrap_or_else(Span::call_site),
342        }
343    }
344}
345impl From<PortIndex> for PortIndexValue {
346    fn from(value: PortIndex) -> Self {
347        match value {
348            PortIndex::Int(x) => Self::Int(x),
349            PortIndex::Path(x) => Self::Path(x),
350        }
351    }
352}
353impl PartialEq for PortIndexValue {
354    fn eq(&self, other: &Self) -> bool {
355        match (self, other) {
356            (Self::Int(l0), Self::Int(r0)) => l0 == r0,
357            (Self::Path(l0), Self::Path(r0)) => l0 == r0,
358            (Self::Elided(_), Self::Elided(_)) => true,
359            _else => false,
360        }
361    }
362}
363impl Eq for PortIndexValue {}
364impl PartialOrd for PortIndexValue {
365    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
366        Some(self.cmp(other))
367    }
368}
369impl Ord for PortIndexValue {
370    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
371        match (self, other) {
372            (Self::Int(s), Self::Int(o)) => s.cmp(o),
373            (Self::Path(s), Self::Path(o)) => s
374                .to_token_stream()
375                .to_string()
376                .cmp(&o.to_token_stream().to_string()),
377            (Self::Elided(_), Self::Elided(_)) => std::cmp::Ordering::Equal,
378            (Self::Int(_), Self::Path(_)) => std::cmp::Ordering::Less,
379            (Self::Path(_), Self::Int(_)) => std::cmp::Ordering::Greater,
380            (_, Self::Elided(_)) => std::cmp::Ordering::Less,
381            (Self::Elided(_), _) => std::cmp::Ordering::Greater,
382        }
383    }
384}
385
386impl Display for PortIndexValue {
387    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
388        match self {
389            PortIndexValue::Int(x) => write!(f, "{}", x.to_token_stream()),
390            PortIndexValue::Path(x) => write!(f, "{}", x.to_token_stream()),
391            PortIndexValue::Elided(_) => write!(f, "[]"),
392        }
393    }
394}
395
396/// The main function of this module. Compiles a [`DfirCode`] AST into a [`DfirGraph`] and
397/// source code, or [`Diagnostic`] errors.
398pub fn build_hfcode(
399    hf_code: DfirCode,
400    root: &TokenStream,
401) -> (Option<(DfirGraph, TokenStream)>, Vec<Diagnostic>) {
402    let flat_graph_builder = FlatGraphBuilder::from_dfir(hf_code);
403    let (mut flat_graph, uses, mut diagnostics) = flat_graph_builder.build();
404    if !diagnostics.iter().any(Diagnostic::is_error) {
405        if let Err(diagnostic) = flat_graph.merge_modules() {
406            diagnostics.push(diagnostic);
407            return (None, diagnostics);
408        }
409
410        eliminate_extra_unions_tees(&mut flat_graph);
411        match partition_graph(flat_graph) {
412            Ok(partitioned_graph) => {
413                let code = partitioned_graph.as_code(
414                    root,
415                    true,
416                    quote::quote! { #( #uses )* },
417                    &mut diagnostics,
418                );
419                if !diagnostics.iter().any(Diagnostic::is_error) {
420                    // Success.
421                    return (Some((partitioned_graph, code)), diagnostics);
422                }
423            }
424            Err(diagnostic) => diagnostics.push(diagnostic),
425        }
426    }
427    (None, diagnostics)
428}
429
430/// Changes all of token's spans to `span`, recursing into groups.
431fn change_spans(tokens: TokenStream, span: Span) -> TokenStream {
432    use proc_macro2::{Group, TokenTree};
433    tokens
434        .into_iter()
435        .map(|token| match token {
436            TokenTree::Group(mut group) => {
437                group.set_span(span);
438                TokenTree::Group(Group::new(
439                    group.delimiter(),
440                    change_spans(group.stream(), span),
441                ))
442            }
443            TokenTree::Ident(mut ident) => {
444                ident.set_span(span.resolved_at(ident.span()));
445                TokenTree::Ident(ident)
446            }
447            TokenTree::Punct(mut punct) => {
448                punct.set_span(span);
449                TokenTree::Punct(punct)
450            }
451            TokenTree::Literal(mut literal) => {
452                literal.set_span(span);
453                TokenTree::Literal(literal)
454            }
455        })
456        .collect()
457}
dfir_lang/graph/mod.rs

dfir_lang/graph/
mod.rs
