flux_refineck/
lib.rs

1//! Refinement type checking
2
3#![feature(
4    associated_type_defaults,
5    box_patterns,
6    if_let_guard,
7    min_specialization,
8    never_type,
9    rustc_private,
10    unwrap_infallible
11)]
12
13extern crate rustc_abi;
14extern crate rustc_data_structures;
15extern crate rustc_errors;
16extern crate rustc_hir;
17extern crate rustc_index;
18extern crate rustc_infer;
19extern crate rustc_middle;
20extern crate rustc_mir_dataflow;
21extern crate rustc_span;
22extern crate rustc_type_ir;
23
24mod checker;
25pub mod compare_impl_item;
26mod ghost_statements;
27pub mod invariants;
28mod primops;
29mod queue;
30mod type_env;
31
32use checker::{Checker, trait_impl_subtyping};
33use flux_common::{dbg, dbg::SpanTrace, result::ResultExt as _};
34use flux_config as config;
35use flux_infer::{
36    fixpoint_encoding::{FixQueryCache, SolutionTrace},
37    infer::{ConstrReason, SubtypeReason, Tag},
38};
39use flux_macros::fluent_messages;
40use flux_middle::{
41    FixpointQueryKind,
42    def_id::MaybeExternId,
43    global_env::GlobalEnv,
44    metrics::{self, Metric, TimingKind},
45    rty::{self, ESpan},
46};
47use rustc_data_structures::unord::UnordMap;
48use rustc_errors::ErrorGuaranteed;
49use rustc_hir::def_id::LocalDefId;
50use rustc_span::Span;
51
52use crate::{checker::errors::ResultExt as _, ghost_statements::compute_ghost_statements};
53
54fluent_messages! { "../locales/en-US.ftl" }
55
56fn report_fixpoint_errors(
57    genv: GlobalEnv,
58    local_id: LocalDefId,
59    errors: Vec<Tag>,
60) -> Result<(), ErrorGuaranteed> {
61    #[expect(clippy::collapsible_else_if, reason = "it looks better")]
62    if genv.should_fail(local_id) {
63        if errors.is_empty() { report_expected_neg(genv, local_id) } else { Ok(()) }
64    } else {
65        if errors.is_empty() { Ok(()) } else { report_errors(genv, errors) }
66    }
67}
68
69pub fn check_fn(
70    genv: GlobalEnv,
71    cache: &mut FixQueryCache,
72    def_id: LocalDefId,
73) -> Result<(), ErrorGuaranteed> {
74    let span = genv.tcx().def_span(def_id);
75
76    // HACK(nilehmann) this will ignore any code generated by a macro. This is a temporary
77    // workaround to deal with a `#[derive(..)]` that generates code that flux cannot handle.
78    // Note that this is required because code generated by a `#[derive(..)]` cannot be
79    // manually trusted or ignored.
80    if !genv.tcx().def_span(def_id).ctxt().is_root() {
81        metrics::incr_metric(Metric::FnTrusted, 1);
82        return Ok(());
83    }
84
85    let opts = genv.infer_opts(def_id);
86
87    // FIXME(nilehmann) we should move this check to `compare_impl_item`
88    if let Some(infcx_root) = trait_impl_subtyping(genv, def_id, opts, span)
89        .with_span(span)
90        .map_err(|err| err.emit(genv, def_id))?
91    {
92        tracing::info!("check_fn::refine-subtyping");
93        let answer = infcx_root
94            .execute_fixpoint_query(cache, MaybeExternId::Local(def_id), FixpointQueryKind::Impl)
95            .emit(&genv)?;
96        tracing::info!("check_fn::fixpoint-subtyping");
97        let errors = answer.errors;
98        report_fixpoint_errors(genv, def_id, errors)?;
99    }
100
101    // Skip trusted functions
102    if genv.trusted(def_id) {
103        metrics::incr_metric(Metric::FnTrusted, 1);
104        return Ok(());
105    }
106
107    metrics::incr_metric(Metric::FnChecked, 1);
108    metrics::time_it(TimingKind::CheckFn(def_id), || -> Result<(), ErrorGuaranteed> {
109        let ghost_stmts = compute_ghost_statements(genv, def_id)
110            .with_span(span)
111            .map_err(|err| err.emit(genv, def_id))?;
112        let mut closures = UnordMap::default();
113
114        let poly_sig = genv
115            .fn_sig(def_id)
116            .with_span(span)
117            .map_err(|err| err.emit(genv, def_id))?
118            .instantiate_identity();
119        let poly_sig = rty::auto_strong(genv, def_id, poly_sig);
120
121        // PHASE 1: infer shape of `TypeEnv` at the entry of join points
122        let shape_result =
123            Checker::run_in_shape_mode(genv, def_id, &ghost_stmts, &mut closures, opts, &poly_sig)
124                .map_err(|err| err.emit(genv, def_id))?;
125
126        // PHASE 2: generate refinement tree constraint
127        let infcx_root = Checker::run_in_refine_mode(
128            genv,
129            def_id,
130            &ghost_stmts,
131            &mut closures,
132            shape_result,
133            opts,
134            &poly_sig,
135        )
136        .map_err(|err| err.emit(genv, def_id))?;
137
138        if genv.proven_externally(def_id) {
139            if flux_config::emit_lean_defs() {
140                infcx_root
141                    .execute_lean_query(MaybeExternId::Local(def_id))
142                    .emit(&genv)
143            } else {
144                panic!("emit_lean_defs should be enabled if there are externally proven items");
145            }
146        } else {
147            // PHASE 3: invoke fixpoint on the constraint
148            let answer = infcx_root
149                .execute_fixpoint_query(
150                    cache,
151                    MaybeExternId::Local(def_id),
152                    FixpointQueryKind::Body,
153                )
154                .emit(&genv)?;
155
156            // DUMP SOLUTION
157            let tcx = genv.tcx();
158            let hir_id = tcx.local_def_id_to_hir_id(def_id);
159            let body_span = tcx.hir_span_with_body(hir_id);
160            dbg::solution!(genv, &answer.solution, body_span);
161
162            let errors = answer.errors;
163            report_fixpoint_errors(genv, def_id, errors)
164        }
165    })?;
166
167    dbg::check_fn_span!(genv.tcx(), def_id).in_scope(|| Ok(()))
168}
169
170fn call_error(genv: GlobalEnv, span: Span, dst_span: Option<ESpan>) -> ErrorGuaranteed {
171    genv.sess()
172        .emit_err(errors::RefineError::call(span, dst_span))
173}
174
175fn ret_error(genv: GlobalEnv, span: Span, dst_span: Option<ESpan>) -> ErrorGuaranteed {
176    genv.sess()
177        .emit_err(errors::RefineError::ret(span, dst_span))
178}
179
180fn report_errors(genv: GlobalEnv, errors: Vec<Tag>) -> Result<(), ErrorGuaranteed> {
181    let mut e = None;
182    for err in errors {
183        let span = err.src_span;
184        e = Some(match err.reason {
185            ConstrReason::Call
186            | ConstrReason::Subtype(SubtypeReason::Input)
187            | ConstrReason::Subtype(SubtypeReason::Requires)
188            | ConstrReason::Predicate => call_error(genv, span, err.dst_span),
189            ConstrReason::Assign => genv.sess().emit_err(errors::AssignError { span }),
190            ConstrReason::Ret
191            | ConstrReason::Subtype(SubtypeReason::Output)
192            | ConstrReason::Subtype(SubtypeReason::Ensures) => ret_error(genv, span, err.dst_span),
193            ConstrReason::Div => genv.sess().emit_err(errors::DivError { span }),
194            ConstrReason::Rem => genv.sess().emit_err(errors::RemError { span }),
195            ConstrReason::Goto(_) => genv.sess().emit_err(errors::GotoError { span }),
196            ConstrReason::Assert(msg) => genv.sess().emit_err(errors::AssertError { span, msg }),
197            ConstrReason::Fold | ConstrReason::FoldLocal => {
198                genv.sess().emit_err(errors::FoldError { span })
199            }
200            ConstrReason::Overflow => genv.sess().emit_err(errors::OverflowError { span }),
201            ConstrReason::Underflow => genv.sess().emit_err(errors::UnderflowError { span }),
202            ConstrReason::Other => genv.sess().emit_err(errors::UnknownError { span }),
203        });
204    }
205
206    if let Some(e) = e { Err(e) } else { Ok(()) }
207}
208
209fn report_expected_neg(genv: GlobalEnv, def_id: LocalDefId) -> Result<(), ErrorGuaranteed> {
210    Err(genv.sess().emit_err(errors::ExpectedNeg {
211        span: genv.tcx().def_span(def_id),
212        def_descr: genv.tcx().def_descr(def_id.to_def_id()),
213    }))
214}
215
216mod errors {
217    use flux_errors::E0999;
218    use flux_macros::{Diagnostic, Subdiagnostic};
219    use flux_middle::rty::ESpan;
220    use rustc_span::Span;
221
222    #[derive(Diagnostic)]
223    #[diag(refineck_goto_error, code = E0999)]
224    pub struct GotoError {
225        #[primary_span]
226        pub span: Span,
227    }
228
229    #[derive(Diagnostic)]
230    #[diag(refineck_assign_error, code = E0999)]
231    pub struct AssignError {
232        #[primary_span]
233        pub span: Span,
234    }
235
236    #[derive(Subdiagnostic)]
237    #[note(refineck_condition_span_note)]
238    pub(crate) struct ConditionSpanNote {
239        #[primary_span]
240        pub span: Span,
241    }
242
243    #[derive(Subdiagnostic)]
244    #[note(refineck_call_span_note)]
245    pub(crate) struct CallSpanNote {
246        #[primary_span]
247        pub span: Span,
248    }
249
250    #[derive(Diagnostic)]
251    #[diag(refineck_refine_error, code = E0999)]
252    pub struct RefineError {
253        #[primary_span]
254        #[label]
255        pub span: Span,
256        cond: &'static str,
257        #[subdiagnostic]
258        span_note: Option<ConditionSpanNote>,
259        #[subdiagnostic]
260        call_span_note: Option<CallSpanNote>,
261    }
262
263    impl RefineError {
264        pub fn call(span: Span, espan: Option<ESpan>) -> Self {
265            RefineError::new("precondition", span, espan)
266        }
267
268        pub fn ret(span: Span, espan: Option<ESpan>) -> Self {
269            RefineError::new("postcondition", span, espan)
270        }
271
272        fn new(cond: &'static str, span: Span, espan: Option<ESpan>) -> RefineError {
273            match espan {
274                Some(dst_span) => {
275                    let span_note = Some(ConditionSpanNote { span: dst_span.span });
276                    let call_span_note = dst_span.base.map(|span| CallSpanNote { span });
277                    RefineError { span, cond, span_note, call_span_note }
278                }
279                None => RefineError { span, cond, span_note: None, call_span_note: None },
280            }
281        }
282    }
283
284    #[derive(Diagnostic)]
285    #[diag(refineck_div_error, code = E0999)]
286    pub struct DivError {
287        #[primary_span]
288        pub span: Span,
289    }
290
291    #[derive(Diagnostic)]
292    #[diag(refineck_rem_error, code = E0999)]
293    pub struct RemError {
294        #[primary_span]
295        pub span: Span,
296    }
297
298    #[derive(Diagnostic)]
299    #[diag(refineck_assert_error, code = E0999)]
300    pub struct AssertError {
301        #[primary_span]
302        pub span: Span,
303        pub msg: &'static str,
304    }
305
306    #[derive(Diagnostic)]
307    #[diag(refineck_fold_error, code = E0999)]
308    pub struct FoldError {
309        #[primary_span]
310        pub span: Span,
311    }
312
313    #[derive(Diagnostic)]
314    #[diag(refineck_overflow_error, code = E0999)]
315    pub struct OverflowError {
316        #[primary_span]
317        pub span: Span,
318    }
319
320    #[derive(Diagnostic)]
321    #[diag(refineck_underflow_error, code = E0999)]
322    pub struct UnderflowError {
323        #[primary_span]
324        pub span: Span,
325    }
326
327    #[derive(Diagnostic)]
328    #[diag(refineck_unknown_error, code = E0999)]
329    pub struct UnknownError {
330        #[primary_span]
331        pub span: Span,
332    }
333
334    #[derive(Diagnostic)]
335    #[diag(refineck_expected_neg, code = E0999)]
336    pub struct ExpectedNeg {
337        #[primary_span]
338        pub span: Span,
339        pub def_descr: &'static str,
340    }
341}
flux_refineck/lib.rs

flux_refineck/
lib.rs
