c2rust-analyze: initial implementation of error recovery

c2rust-analyze/Cargo.toml

@@ -19,6 +19,7 @@ assert_matches = "1.5.0"
 indexmap = "1.9.2"
 env_logger = "0.10.0"
 log = "0.4.17"
+backtrace = "0.3.67"
 
 [build-dependencies]
 c2rust-build-paths = { path = "../c2rust-build-paths", version = "0.18.0" }

c2rust-analyze/src/borrowck/type_check.rs

@@ -2,6 +2,7 @@ use crate::borrowck::atoms::{AllFacts, AtomMaps, Loan, Origin, Path, Point, SubP
 use crate::borrowck::{construct_adt_origins, LTy, LTyCtxt, Label, OriginParam};
 use crate::c_void_casts::CVoidCasts;
 use crate::context::PermissionSet;
+use crate::panic_detail;
 use crate::util::{self, ty_callee, Callee};
 use crate::AdtMetadataTable;
 use assert_matches::assert_matches;
@@ -429,6 +430,7 @@ impl<'tcx> TypeChecker<'tcx, '_> {
     }
 
     pub fn visit_statement(&mut self, stmt: &Statement<'tcx>) {
+        let _g = panic_detail::set_current_span(stmt.source_info.span);
         // TODO(spernsteiner): other `StatementKind`s will be handled in the future
         #[allow(clippy::single_match)]
         match stmt.kind {
@@ -445,6 +447,7 @@ impl<'tcx> TypeChecker<'tcx, '_> {
 
     pub fn visit_terminator(&mut self, term: &Terminator<'tcx>) {
         eprintln!("borrowck: visit_terminator({:?})", term.kind);
+        let _g = panic_detail::set_current_span(term.source_info.span);
         // TODO(spernsteiner): other `TerminatorKind`s will be handled in the future
         #[allow(clippy::single_match)]
         match term.kind {

c2rust-analyze/src/context.rs

@@ -1,6 +1,7 @@
 use crate::borrowck::{AdtMetadata, FieldMetadata, OriginArg, OriginParam};
 use crate::c_void_casts::CVoidCasts;
 use crate::labeled_ty::{LabeledTy, LabeledTyCtxt};
+use crate::panic_detail::PanicDetail;
 use crate::pointer_id::{
     GlobalPointerTable, LocalPointerTable, NextGlobalPointerId, NextLocalPointerId, PointerTable,
     PointerTableMut,
@@ -272,7 +273,13 @@ pub struct GlobalAnalysisCtxt<'tcx> {
 
     ptr_info: GlobalPointerTable<PointerInfo>,
 
+    /// Map from a function to all of its callers.
+    pub fn_callers: HashMap<DefId, Vec<DefId>>,
+
     pub fn_sigs: HashMap<DefId, LFnSig<'tcx>>,
+    /// `DefId`s of functions where analysis failed, and a [`PanicDetail`] explaining the reason
+    /// for each failure.
+    pub fns_failed: HashMap<DefId, PanicDetail>,
 
     pub field_ltys: HashMap<DefId, LTy<'tcx>>,
 
@@ -522,7 +529,9 @@ impl<'tcx> GlobalAnalysisCtxt<'tcx> {
             tcx,
             lcx: LabeledTyCtxt::new(tcx),
             ptr_info: GlobalPointerTable::empty(),
+            fn_callers: HashMap::new(),
             fn_sigs: HashMap::new(),
+            fns_failed: HashMap::new(),
             field_ltys: HashMap::new(),
             static_tys: HashMap::new(),
             addr_of_static: HashMap::new(),
@@ -566,7 +575,9 @@ impl<'tcx> GlobalAnalysisCtxt<'tcx> {
             tcx: _,
             lcx,
             ref mut ptr_info,
+            fn_callers: _,
             ref mut fn_sigs,
+            fns_failed: _,
             ref mut field_ltys,
             ref mut static_tys,
             ref mut addr_of_static,
@@ -620,6 +631,27 @@ impl<'tcx> GlobalAnalysisCtxt<'tcx> {
             self.assign_pointer_to_field(field);
         }
     }
+
+    pub fn fn_failed(&mut self, did: DefId) -> bool {
+        self.fns_failed.contains_key(&did)
+    }
+
+    pub fn mark_fn_failed(&mut self, did: DefId, detail: PanicDetail) {
+        if self.fns_failed.contains_key(&did) {
+            return;
+        }
+
+        self.fns_failed.insert(did, detail);
+
+        // This is the first time marking `did` as failed, so also mark all of its callers.
+        let callers = self.fn_callers.get(&did).cloned().unwrap_or(Vec::new());
+        for caller in callers {
+            self.mark_fn_failed(
+                caller,
+                PanicDetail::new(format!("analysis failed on callee {:?}", did)),
+            );
+        }
+    }
 }
 
 impl<'a, 'tcx> AnalysisCtxt<'a, 'tcx> {

c2rust-analyze/src/dataflow/type_check.rs

@@ -1,6 +1,7 @@
 use super::DataflowConstraints;
 use crate::c_void_casts::CVoidCastDirection;
 use crate::context::{AnalysisCtxt, LTy, PermissionSet, PointerId};
+use crate::panic_detail;
 use crate::util::{describe_rvalue, is_null_const, ty_callee, Callee, RvalueDesc};
 use assert_matches::assert_matches;
 use rustc_hir::def_id::DefId;
@@ -317,11 +318,12 @@ impl<'tcx> TypeChecker<'tcx, '_> {
 
     pub fn visit_statement(&mut self, stmt: &Statement<'tcx>, loc: Location) {
         eprintln!("visit_statement({:?})", stmt);
-
         if self.acx.c_void_casts.should_skip_stmt(loc) {
             return;
         }
 
+        let _g = panic_detail::set_current_span(stmt.source_info.span);
+
         // TODO(spernsteiner): other `StatementKind`s will be handled in the future
         #[allow(clippy::single_match)]
         match stmt.kind {
@@ -342,6 +344,7 @@ impl<'tcx> TypeChecker<'tcx, '_> {
     pub fn visit_terminator(&mut self, term: &Terminator<'tcx>, loc: Location) {
         eprintln!("visit_terminator({:?})", term.kind);
         let tcx = self.acx.tcx();
+        let _g = panic_detail::set_current_span(term.source_info.span);
         // TODO(spernsteiner): other `TerminatorKind`s will be handled in the future
         #[allow(clippy::single_match)]
         match term.kind {