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, result::ResultExt as _};
34use flux_infer::{
35    fixpoint_encoding::FixQueryCache,
36    infer::{ConstrReason, SubtypeReason, Tag},
37};
38use flux_macros::fluent_messages;
39use flux_middle::{
40    FixpointQueryKind,
41    def_id::MaybeExternId,
42    global_env::GlobalEnv,
43    rty::{self, ESpan},
44    timings,
45};
46use rustc_data_structures::unord::UnordMap;
47use rustc_errors::ErrorGuaranteed;
48use rustc_hir::def_id::LocalDefId;
49use rustc_span::Span;
50
51use crate::{checker::errors::ResultExt as _, ghost_statements::compute_ghost_statements};
52
53fluent_messages! { "../locales/en-US.ftl" }
54
55fn report_fixpoint_errors(
56    genv: GlobalEnv,
57    local_id: LocalDefId,
58    errors: Vec<Tag>,
59) -> Result<(), ErrorGuaranteed> {
60    #[expect(clippy::collapsible_else_if, reason = "it looks better")]
61    if genv.should_fail(local_id) {
62        if errors.is_empty() { report_expected_neg(genv, local_id) } else { Ok(()) }
63    } else {
64        if errors.is_empty() { Ok(()) } else { report_errors(genv, errors) }
65    }
66}
67
68pub fn check_fn(
69    genv: GlobalEnv,
70    cache: &mut FixQueryCache,
71    def_id: LocalDefId,
72) -> Result<(), ErrorGuaranteed> {
73    let span = genv.tcx().def_span(def_id);
74
75    // HACK(nilehmann) this will ignore any code generated by a macro. This is a temporary
76    // workaround to deal with a `#[derive(..)]` that generates code that flux cannot handle.
77    // Note that this is required because code generated by a `#[derive(..)]` cannot be
78    // manually trusted or ignored.
79    if !genv.tcx().def_span(def_id).ctxt().is_root() {
80        return Ok(());
81    }
82
83    // Skip trait methods without body
84    if genv.tcx().hir_node_by_def_id(def_id).body_id().is_none() {
85        return Ok(());
86    }
87
88    let opts = genv.infer_opts(def_id);
89
90    // FIXME(nilehmann) we should move this check to `compare_impl_item`
91    if let Some(infcx_root) = trait_impl_subtyping(genv, def_id, opts, span)
92        .with_span(span)
93        .map_err(|err| err.emit(genv, def_id))?
94    {
95        tracing::info!("check_fn::refine-subtyping");
96        let errors = infcx_root
97            .execute_fixpoint_query(cache, MaybeExternId::Local(def_id), FixpointQueryKind::Impl)
98            .emit(&genv)?;
99        tracing::info!("check_fn::fixpoint-subtyping");
100        report_fixpoint_errors(genv, def_id, errors)?;
101    }
102
103    // Skip trusted functions
104    if genv.trusted(def_id) {
105        return Ok(());
106    }
107
108    timings::time_it(timings::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        // PHASE 1: infer shape of `TypeEnv` at the entry of join points
114        let shape_result =
115            Checker::run_in_shape_mode(genv, def_id, &ghost_stmts, &mut closures, opts)
116                .map_err(|err| err.emit(genv, def_id))?;
117
118        // PHASE 2: generate refinement tree constraint
119        let infcx_root = Checker::run_in_refine_mode(
120            genv,
121            def_id,
122            &ghost_stmts,
123            &mut closures,
124            shape_result,
125            opts,
126        )
127        .map_err(|err| err.emit(genv, def_id))?;
128
129        // PHASE 3: invoke fixpoint on the constraint
130        let errors = infcx_root
131            .execute_fixpoint_query(cache, MaybeExternId::Local(def_id), FixpointQueryKind::Body)
132            .emit(&genv)?;
133        report_fixpoint_errors(genv, def_id, errors)
134    })?;
135
136    dbg::check_fn_span!(genv.tcx(), def_id).in_scope(|| Ok(()))
137}
138
139fn call_error(genv: GlobalEnv, span: Span, dst_span: Option<ESpan>) -> ErrorGuaranteed {
140    genv.sess()
141        .emit_err(errors::RefineError::call(span, dst_span))
142}
143
144fn ret_error(genv: GlobalEnv, span: Span, dst_span: Option<ESpan>) -> ErrorGuaranteed {
145    genv.sess()
146        .emit_err(errors::RefineError::ret(span, dst_span))
147}
148
149fn report_errors(genv: GlobalEnv, errors: Vec<Tag>) -> Result<(), ErrorGuaranteed> {
150    let mut e = None;
151    for err in errors {
152        let span = err.src_span;
153        e = Some(match err.reason {
154            ConstrReason::Call
155            | ConstrReason::Subtype(SubtypeReason::Input)
156            | ConstrReason::Subtype(SubtypeReason::Requires)
157            | ConstrReason::Predicate => call_error(genv, span, err.dst_span),
158            ConstrReason::Assign => genv.sess().emit_err(errors::AssignError { span }),
159            ConstrReason::Ret
160            | ConstrReason::Subtype(SubtypeReason::Output)
161            | ConstrReason::Subtype(SubtypeReason::Ensures) => ret_error(genv, span, err.dst_span),
162            ConstrReason::Div => genv.sess().emit_err(errors::DivError { span }),
163            ConstrReason::Rem => genv.sess().emit_err(errors::RemError { span }),
164            ConstrReason::Goto(_) => genv.sess().emit_err(errors::GotoError { span }),
165            ConstrReason::Assert(msg) => genv.sess().emit_err(errors::AssertError { span, msg }),
166            ConstrReason::Fold | ConstrReason::FoldLocal => {
167                genv.sess().emit_err(errors::FoldError { span })
168            }
169            ConstrReason::Overflow => genv.sess().emit_err(errors::OverflowError { span }),
170            ConstrReason::Underflow => genv.sess().emit_err(errors::UnderflowError { span }),
171            ConstrReason::Other => genv.sess().emit_err(errors::UnknownError { span }),
172        });
173    }
174
175    if let Some(e) = e { Err(e) } else { Ok(()) }
176}
177
178fn report_expected_neg(genv: GlobalEnv, def_id: LocalDefId) -> Result<(), ErrorGuaranteed> {
179    Err(genv.sess().emit_err(errors::ExpectedNeg {
180        span: genv.tcx().def_span(def_id),
181        def_descr: genv.tcx().def_descr(def_id.to_def_id()),
182    }))
183}
184
185mod errors {
186    use flux_errors::E0999;
187    use flux_macros::{Diagnostic, Subdiagnostic};
188    use flux_middle::rty::ESpan;
189    use rustc_span::Span;
190
191    #[derive(Diagnostic)]
192    #[diag(refineck_goto_error, code = E0999)]
193    pub struct GotoError {
194        #[primary_span]
195        pub span: Span,
196    }
197
198    #[derive(Diagnostic)]
199    #[diag(refineck_assign_error, code = E0999)]
200    pub struct AssignError {
201        #[primary_span]
202        pub span: Span,
203    }
204
205    #[derive(Subdiagnostic)]
206    #[note(refineck_condition_span_note)]
207    pub(crate) struct ConditionSpanNote {
208        #[primary_span]
209        pub span: Span,
210    }
211
212    #[derive(Subdiagnostic)]
213    #[note(refineck_call_span_note)]
214    pub(crate) struct CallSpanNote {
215        #[primary_span]
216        pub span: Span,
217    }
218
219    #[derive(Diagnostic)]
220    #[diag(refineck_refine_error, code = E0999)]
221    pub struct RefineError {
222        #[primary_span]
223        #[label]
224        pub span: Span,
225        cond: &'static str,
226        #[subdiagnostic]
227        span_note: Option<ConditionSpanNote>,
228        #[subdiagnostic]
229        call_span_note: Option<CallSpanNote>,
230    }
231
232    impl RefineError {
233        pub fn call(span: Span, espan: Option<ESpan>) -> Self {
234            RefineError::new("precondition", span, espan)
235        }
236
237        pub fn ret(span: Span, espan: Option<ESpan>) -> Self {
238            RefineError::new("postcondition", span, espan)
239        }
240
241        fn new(cond: &'static str, span: Span, espan: Option<ESpan>) -> RefineError {
242            match espan {
243                Some(dst_span) => {
244                    let span_note = Some(ConditionSpanNote { span: dst_span.span });
245                    let call_span_note = dst_span.base.map(|span| CallSpanNote { span });
246                    RefineError { span, cond, span_note, call_span_note }
247                }
248                None => RefineError { span, cond, span_note: None, call_span_note: None },
249            }
250        }
251    }
252
253    #[derive(Diagnostic)]
254    #[diag(refineck_div_error, code = E0999)]
255    pub struct DivError {
256        #[primary_span]
257        pub span: Span,
258    }
259
260    #[derive(Diagnostic)]
261    #[diag(refineck_rem_error, code = E0999)]
262    pub struct RemError {
263        #[primary_span]
264        pub span: Span,
265    }
266
267    #[derive(Diagnostic)]
268    #[diag(refineck_assert_error, code = E0999)]
269    pub struct AssertError {
270        #[primary_span]
271        pub span: Span,
272        pub msg: &'static str,
273    }
274
275    #[derive(Diagnostic)]
276    #[diag(refineck_fold_error, code = E0999)]
277    pub struct FoldError {
278        #[primary_span]
279        pub span: Span,
280    }
281
282    #[derive(Diagnostic)]
283    #[diag(refineck_overflow_error, code = E0999)]
284    pub struct OverflowError {
285        #[primary_span]
286        pub span: Span,
287    }
288
289    #[derive(Diagnostic)]
290    #[diag(refineck_underflow_error, code = E0999)]
291    pub struct UnderflowError {
292        #[primary_span]
293        pub span: Span,
294    }
295
296    #[derive(Diagnostic)]
297    #[diag(refineck_unknown_error, code = E0999)]
298    pub struct UnknownError {
299        #[primary_span]
300        pub span: Span,
301    }
302
303    #[derive(Diagnostic)]
304    #[diag(refineck_expected_neg, code = E0999)]
305    pub struct ExpectedNeg {
306        #[primary_span]
307        pub span: Span,
308        pub def_descr: &'static str,
309    }
310}
flux_refineck/lib.rs

flux_refineck/
lib.rs
