Scanner: log crate-level visibility of functions

tests/script-based-pre/tool-scanner/scanner-test.expected

@@ -1,7 +1,7 @@
 5 test_scan_fn_loops.csv
 20 test_scan_functions.csv
 5 test_scan_input_tys.csv
-17 test_scan_overall.csv
+19 test_scan_overall.csv
 3 test_scan_recursion.csv
 9 test_scan_unsafe_distance.csv
 6 test_scan_unsafe_ops.csv

tools/scanner/src/analysis.rs

@@ -7,6 +7,8 @@ use crate::info;
 use csv::WriterBuilder;
 use graph_cycles::Cycles;
 use petgraph::graph::Graph;
+use rustc_middle::ty::TyCtxt;
+use rustc_smir::rustc_internal;
 use serde::{Serialize, Serializer, ser::SerializeStruct};
 use stable_mir::mir::mono::Instance;
 use stable_mir::mir::visit::{Location, PlaceContext, PlaceRef};
@@ -36,6 +38,7 @@ struct FnStats {
     has_unsafe_ops: Option<bool>,
     has_unsupported_input: Option<bool>,
     has_loop_or_iterator: Option<bool>,
+    is_public: Option<bool>,
 }
 
 impl FnStats {
@@ -46,6 +49,7 @@ impl FnStats {
             has_unsafe_ops: None,
             has_unsupported_input: None,
             has_loop_or_iterator: None,
+            is_public: None,
         }
     }
 }
@@ -235,6 +239,29 @@ impl OverallStats {
                 .collect::<Vec<_>>(),
         );
     }
+
+    /// Iterate over all functions defined in this crate and log public vs private
+    pub fn public_fns(&mut self, tcx: &TyCtxt) {
+        let all_items = stable_mir::all_local_items();
+        let (public_fns, private_fns) = all_items
+            .into_iter()
+            .filter_map(|item| {
+                let kind = item.ty().kind();
+                if !kind.is_fn() {
+                    return None;
+                };
+                let int_def_id = rustc_internal::internal(*tcx, item.def_id());
+                let is_public = tcx.visibility(int_def_id).is_public()
+                    || tcx.visibility(int_def_id).is_visible_locally();
+                self.fn_stats.get_mut(&item).unwrap().is_public = Some(is_public);
+                Some((item, is_public))
+            })
+            .partition::<Vec<(CrateItem, bool)>, _>(|(_, is_public)| *is_public);
+        self.counters.extend_from_slice(&[
+            ("public_fns", public_fns.len()),
+            ("private_fns", private_fns.len()),
+        ]);
+    }
 }
 
 macro_rules! fn_props {

tools/scanner/src/lib.rs

@@ -68,6 +68,8 @@ pub enum Analysis {
     Recursion,
     /// Collect information about transitive usage of unsafe.
     UnsafeDistance,
+    /// Collect information about function visibility.
+    PublicFns,
 }
 
 fn info(msg: String) {
@@ -103,6 +105,7 @@ fn analyze_crate(tcx: TyCtxt, analyses: &[Analysis]) -> ControlFlow<()> {
             Analysis::FnLoops => crate_stats.loops(out_path),
             Analysis::Recursion => crate_stats.recursion(out_path),
             Analysis::UnsafeDistance => crate_stats.unsafe_distance(out_path),
+            Analysis::PublicFns => crate_stats.public_fns(&tcx),
         }
     }
     crate_stats.store_csv(base_path, &file_stem);