kinda works

src/build.rs

@@ -1,12 +1,17 @@
 use anyhow::{Context, Result};
 use rustfix::diagnostics::Diagnostic;
 use serde::Deserialize;
-use std::{collections::HashSet, fmt::Display, path::PathBuf, process::Command};
+use std::{collections::HashSet, fmt::Display, path::PathBuf, process::Command, rc::Rc};
 
 use crate::Options;
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Build {
+    inner: Rc<BuildInner>,
+}
+
+#[derive(Debug)]
+struct BuildInner {
     mode: BuildMode,
     input_path: PathBuf,
     no_verify: bool,
@@ -29,21 +34,23 @@ impl Build {
             BuildMode::Rustc
         };
         Self {
-            mode,
-            input_path: options.path.clone(),
-            no_verify: options.no_verify,
+            inner: Rc::new(BuildInner {
+                mode,
+                input_path: options.path.clone(),
+                no_verify: options.no_verify,
+            }),
         }
     }
 
     pub fn build(&self) -> Result<BuildResult> {
-        if self.no_verify {
+        if self.inner.no_verify {
             return Ok(BuildResult {
                 reproduces_issue: false,
                 no_verify: true,
             });
         }
 
-        let reproduces_issue = match &self.mode {
+        let reproduces_issue = match &self.inner.mode {
             BuildMode::Cargo => {
                 let mut cmd = Command::new("cargo");
                 cmd.arg("build");
@@ -62,7 +69,7 @@ impl Build {
             BuildMode::Rustc => {
                 let mut cmd = Command::new("rustc");
                 cmd.args(["--edition", "2018"]);
-                cmd.arg(&self.input_path);
+                cmd.arg(&self.inner.input_path);
 
                 cmd.output()
                     .context("spawning rustc process")?
@@ -74,12 +81,12 @@ impl Build {
 
         Ok(BuildResult {
             reproduces_issue,
-            no_verify: self.no_verify,
+            no_verify: self.inner.no_verify,
         })
     }
 
-    pub fn get_suggestions(&self) -> Result<(Vec<Diagnostic>, Vec<rustfix::Suggestion>)> {
-        let diags = match self.mode {
+    pub fn get_diags(&self) -> Result<(Vec<Diagnostic>, Vec<rustfix::Suggestion>)> {
+        let diags = match self.inner.mode {
             BuildMode::Cargo => {
                 let mut cmd = Command::new("cargo");
                 cmd.args(["build", "--message-format=json"]);
@@ -102,7 +109,7 @@ impl Build {
             BuildMode::Rustc => {
                 let mut cmd = std::process::Command::new("rustc");
                 cmd.args(["--edition", "2018", "--error-format=json"]);
-                cmd.arg(&self.input_path);
+                cmd.arg(&self.inner.input_path);
 
                 let output = cmd.output()?.stderr;
                 let output = String::from_utf8(output)?;

src/everybody_loops.rs

@@ -1,7 +1,7 @@
 use quote::ToTokens;
 use syn::{parse_quote, visit_mut::VisitMut};
 
-use crate::processor::{ProcessChecker, ProcessState, Processor};
+use crate::processor::{ProcessChecker, ProcessState, Processor, SourceFile};
 
 struct Visitor<'a> {
     current_path: Vec<String>,
@@ -68,6 +68,7 @@ impl Processor for EverybodyLoops {
     fn process_file(
         &mut self,
         krate: &mut syn::File,
+        _: &SourceFile,
         checker: &mut ProcessChecker,
     ) -> ProcessState {
         let mut visitor = Visitor::new(checker);

src/lib.rs

@@ -12,7 +12,7 @@ use anyhow::{Context, Result};
 use clap::Parser;
 use processor::Minimizer;
 
-use crate::{everybody_loops::EverybodyLoops, processor::Processor, privatize::Privatize};
+use crate::{everybody_loops::EverybodyLoops, privatize::Privatize, processor::Processor};
 
 #[derive(clap::Parser)]
 pub struct Options {
@@ -30,7 +30,7 @@ pub fn minimize() -> Result<()> {
 
     let build = build::Build::new(&options);
 
-    let mut minimizer = Minimizer::new_glob_dir(&options.path, build, &options);
+    let mut minimizer = Minimizer::new_glob_dir(&options.path, build);
 
     println!("{minimizer:?}");
 

src/privatize.rs

@@ -1,6 +1,6 @@
 use syn::{parse_quote, visit_mut::VisitMut, Visibility};
 
-use crate::processor::{ProcessChecker, Processor, ProcessState};
+use crate::processor::{ProcessChecker, ProcessState, Processor, SourceFile};
 
 struct Visitor {
     pub_crate: Visibility,
@@ -29,7 +29,7 @@ impl VisitMut for Visitor {
 pub struct Privatize {}
 
 impl Processor for Privatize {
-    fn process_file(&mut self, krate: &mut syn::File, _: &mut ProcessChecker) -> ProcessState {
+    fn process_file(&mut self, krate: &mut syn::File, _: &SourceFile, _: &mut ProcessChecker) -> ProcessState {
         let mut visitor = Visitor::new();
         visitor.visit_file_mut(krate);
         visitor.process_state

src/processor/files.rs

@@ -4,7 +4,7 @@ use std::{
     path::{Path, PathBuf},
 };
 
-#[derive(Debug, PartialEq, Eq, Hash)]
+#[derive(Debug, PartialEq, Eq, Clone, Hash)]
 pub struct SourceFile {
     pub path: PathBuf,
 }
@@ -72,9 +72,8 @@ impl SourceFile {
     }
 }
 
-
 impl Changes {
     pub fn had_changes(&self) -> bool {
         self.any_change
     }
-}
+}

src/processor/mod.rs

@@ -5,13 +5,24 @@ use std::{collections::HashSet, ffi::OsStr, path::Path};
 
 use anyhow::{ensure, Context, Result};
 
-use crate::{build::Build, processor::files::Changes, Options};
+use crate::{build::Build, processor::files::Changes};
 
-use self::files::SourceFile;
+pub use self::files::SourceFile;
 
 pub trait Processor {
-    fn process_file(&mut self, krate: &mut syn::File, checker: &mut ProcessChecker)
-        -> ProcessState;
+    fn refresh_state(&mut self) -> Result<()> {
+        Ok(())
+    }
+
+    /// Process a file. The state of the processor might get invalidated in the process as signaled with
+    /// `ProcessState::FileInvalidated`. When a file is invalidated, the minimizer will call `Processor::refersh_state`
+    /// before calling the this function on the same file again.
+    fn process_file(
+        &mut self,
+        krate: &mut syn::File,
+        file: &SourceFile,
+        checker: &mut ProcessChecker,
+    ) -> ProcessState;
 
     fn name(&self) -> &'static str;
 }
@@ -27,11 +38,10 @@ pub enum ProcessState {
 pub struct Minimizer {
     files: Vec<SourceFile>,
     build: Build,
-    no_verify: bool,
 }
 
 impl Minimizer {
-    pub fn new_glob_dir(path: &Path, build: Build, options: &Options) -> Self {
+    pub fn new_glob_dir(path: &Path, build: Build) -> Self {
         let walk = walkdir::WalkDir::new(path);
 
         let files = walk
@@ -49,29 +59,25 @@ impl Minimizer {
             })
             .collect();
 
-        Self {
-            files,
-            build,
-            no_verify: options.no_verify,
-        }
+        Self { files, build }
     }
 
     pub fn run_passes<'a>(
         &mut self,
-        passes: impl IntoIterator<Item = Box<dyn Processor>>,
+        passes: impl IntoIterator<Item = Box<dyn Processor + 'a>>,
     ) -> Result<()> {
         let inital_build = self.build.build()?;
         println!("Initial build: {}", inital_build);
-        if !self.no_verify {
-            ensure!(
-                inital_build.reproduces_issue(),
-                "Initial build must reproduce issue"
-            );
-        }
+        ensure!(
+            inital_build.reproduces_issue(),
+            "Initial build must reproduce issue"
+        );
 
         let mut invalidated_files = HashSet::new();
 
         for mut pass in passes {
+            let mut refresh_and_try_again = false;
+
             'pass: loop {
                 println!("Starting a round of {}", pass.name());
                 let mut changes = Changes::default();
@@ -88,7 +94,7 @@ impl Minimizer {
                     let mut krate = syn::parse_file(change.before_content())
                         .with_context(|| format!("parsing file {file_display}"))?;
 
-                    let has_made_change = pass.process_file(&mut krate, &mut ProcessChecker {});
+                    let has_made_change = pass.process_file(&mut krate, file, &mut ProcessChecker {});
 
                     match has_made_change {
                         ProcessState::Changed | ProcessState::FileInvalidated => {
@@ -117,8 +123,18 @@ impl Minimizer {
                 }
 
                 if !changes.had_changes() {
+                    if !refresh_and_try_again && invalidated_files.len() > 0 {
+                        // A few files have been invalidated, let's refresh and try these again.
+                        pass.refresh_state().context("refreshing state for pass")?;
+                        refresh_and_try_again = true;
+                        println!("Refreshing files for {}", pass.name());
+                        continue;
+                    }
+
                     println!("Finished {}", pass.name());
                     break 'pass;
+                } else {
+                    refresh_and_try_again = false;
                 }
             }
         }

src/processor/reaper.rs

@@ -1,10 +1,16 @@
 //! Deletes dead code.
 
-use super::{files::Changes, Minimizer, ProcessState, Processor};
+use crate::build::Build;
+
+use super::{files::Changes, Minimizer, ProcessState, Processor, SourceFile};
 use anyhow::{ensure, Context, Result};
 use proc_macro2::Span;
 use rustfix::{diagnostics::Diagnostic, Suggestion};
-use std::{collections::HashMap, ops::Range, path::Path};
+use std::{
+    collections::{HashMap, HashSet},
+    ops::Range,
+    path::Path,
+};
 use syn::{visit_mut::VisitMut, ImplItem, Item};
 
 fn file_for_suggestion(suggestion: &Suggestion) -> &str {
@@ -15,16 +21,14 @@ impl Minimizer {
     pub fn delete_dead_code(&mut self) -> Result<()> {
         let inital_build = self.build.build()?;
         println!("Before reaper: {}", inital_build);
-        if !self.no_verify {
-            ensure!(
-                inital_build.reproduces_issue(),
-                "Initial build must reproduce issue"
-            );
-        }
+        ensure!(
+            inital_build.reproduces_issue(),
+            "Initial build must reproduce issue"
+        );
 
         let (diags, suggestions) = self
             .build
-            .get_suggestions()
+            .get_diags()
             .context("getting suggestions from rustc")?;
 
         let mut suggestions_for_file = HashMap::<_, Vec<_>>::new();
@@ -38,11 +42,10 @@ impl Minimizer {
         // Always unconditionally apply unused imports.
         self.apply_unused_imports(&suggestions_for_file)?;
 
-        self.run_passes([Box::new(DeleteUnusedFunctions {
-            diags,
-            invalid: false,
-        }) as Box<dyn Processor>])
-            .context("deleting unused functions")?;
+        self.run_passes([
+            Box::new(DeleteUnusedFunctions::new(self.build.clone(), diags)) as Box<dyn Processor>,
+        ])
+        .context("deleting unused functions")?;
 
         Ok(())
     }
@@ -91,22 +94,44 @@ impl Minimizer {
 
 struct DeleteUnusedFunctions {
     diags: Vec<Diagnostic>,
-    invalid: bool,
+    build: Build,
+    invalid: HashSet<SourceFile>,
+}
+
+impl DeleteUnusedFunctions {
+    fn new(build: Build, diags: Vec<Diagnostic>) -> Self {
+        DeleteUnusedFunctions {
+            diags,
+            build,
+            invalid: HashSet::new(),
+        }
+    }
 }
 
 impl Processor for DeleteUnusedFunctions {
+    fn refresh_state(&mut self) -> Result<()> {
+        let (diags, _) = self.build.get_diags().context("getting diagnostics")?;
+        self.diags = diags;
+        self.invalid = HashSet::new();
+        Ok(())
+    }
+
     fn process_file(
         &mut self,
         krate: &mut syn::File,
+        file: &SourceFile,
         _: &mut super::ProcessChecker,
     ) -> ProcessState {
-        assert!(!self.invalid, "processing with invalid state");
+        assert!(
+            !self.invalid.contains(file),
+            "processing with invalid state"
+        );
 
-        let mut visitor = FindUnusedFunction::new(self.diags.iter());
+        let mut visitor = FindUnusedFunction::new(file, self.diags.iter());
         visitor.visit_file_mut(krate);
 
         if visitor.process_state == ProcessState::FileInvalidated {
-            self.invalid = true;
+            self.invalid.insert(file.clone());
         }
 
         visitor.process_state
@@ -143,7 +168,7 @@ struct FindUnusedFunction {
 }
 
 impl FindUnusedFunction {
-    fn new<'a>(diags: impl Iterator<Item = &'a Diagnostic>) -> Self {
+    fn new<'a>(file: &SourceFile, diags: impl Iterator<Item = &'a Diagnostic>) -> Self {
         let unused_functions = diags
             .filter_map(|diag| {
                 // FIXME: use `code` correctly
@@ -167,6 +192,10 @@ impl FindUnusedFunction {
                     "encountered multiline span in dead_code"
                 );
 
+                if Path::new(&span.file_name) != file.path {
+                    return None;
+                }
+
                 Some(Unused {
                     name,
                     line: span.line_start,

test-cases/unused-code/src/other.rs

@@ -1,3 +1,3 @@
 fn unused() {
     loop {}
-}
+}