things

Cargo.lock

@@ -156,6 +156,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "rustfix",
+ "serde",
  "serde_json",
  "syn",
  "walkdir",
@@ -1107,18 +1108,18 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.145"
+version = "1.0.151"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "728eb6351430bccb993660dfffc5a72f91ccc1295abaa8ce19b27ebe4f75568b"
+checksum = "97fed41fc1a24994d044e6db6935e69511a1153b52c15eb42493b26fa87feba0"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.145"
+version = "1.0.151"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "81fa1584d3d1bcacd84c277a0dfe21f5b0f6accf4a23d04d4c6d61f1af522b4c"
+checksum = "255abe9a125a985c05190d687b320c12f9b1f0b99445e608c21ba0782c719ad8"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1194,9 +1195,9 @@ checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
 
 [[package]]
 name = "syn"
-version = "1.0.102"
+version = "1.0.106"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3fcd952facd492f9be3ef0d0b7032a6e442ee9b361d4acc2b1d0c4aaa5f613a1"
+checksum = "09ee3a69cd2c7e06684677e5629b3878b253af05e4714964204279c6bc02cf0b"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -16,6 +16,7 @@ prettyplease = "0.1.19"
 proc-macro2 = { version = "1.0.48", features = ["span-locations"] }
 quote = "1.0.21"
 rustfix = "0.6.1"
+serde = { version = "1.0.151", features = ["derive"] }
 serde_json = "1.0.90"
 syn = { version = "1.0.101", features = ["full", "visit", "visit-mut"] }
 walkdir = "2.3.2"

src/build.rs

@@ -1,6 +1,7 @@
 use anyhow::{Context, Result};
 use rustfix::diagnostics::Diagnostic;
-use std::{collections::HashSet, fmt::Display, path::PathBuf};
+use serde::Deserialize;
+use std::{collections::HashSet, fmt::Display, path::PathBuf, process::Command};
 
 use crate::Options;
 
@@ -35,9 +36,16 @@ impl Build {
     }
 
     pub fn build(&self) -> Result<BuildResult> {
+        if self.no_verify {
+            return Ok(BuildResult {
+                reproduces_issue: false,
+                no_verify: true,
+            });
+        }
+
         let reproduces_issue = match &self.mode {
             BuildMode::Cargo => {
-                let mut cmd = std::process::Command::new("cargo");
+                let mut cmd = Command::new("cargo");
                 cmd.arg("build");
 
                 let output =
@@ -47,12 +55,12 @@ impl Build {
                 output.contains("internal compiler error")
             }
             BuildMode::Script(script_path) => {
-                let mut cmd = std::process::Command::new(script_path);
+                let mut cmd = Command::new(script_path);
 
                 cmd.output().context("spawning script")?.status.success()
             }
             BuildMode::Rustc => {
-                let mut cmd = std::process::Command::new("rustc");
+                let mut cmd = Command::new("rustc");
                 cmd.args(["--edition", "2018"]);
                 cmd.arg(&self.input_path);
 
@@ -71,11 +79,26 @@ impl Build {
     }
 
     pub fn get_suggestions(&self) -> Result<(Vec<Diagnostic>, Vec<rustfix::Suggestion>)> {
-        match self.mode {
+        let diags = match self.mode {
             BuildMode::Cargo => {
-                todo!();
+                let mut cmd = Command::new("cargo");
+                cmd.args(["build", "--message-format=json"]);
+
+                let cmd_output = cmd.output()?;
+                let output = String::from_utf8(cmd_output.stdout.clone())?;
+
+                let messages = serde_json::Deserializer::from_str(&output)
+                    .into_iter::<CargoJsonCompileMessage>()
+                    .collect::<Result<Vec<_>, _>>()?;
+
+                let diags = messages
+                    .into_iter()
+                    .filter(|msg| msg.reason == "compiler-message")
+                    .flat_map(|msg| msg.message)
+                    .collect();
+
+                diags
             }
-            BuildMode::Script(_) => todo!(),
             BuildMode::Rustc => {
                 let mut cmd = std::process::Command::new("rustc");
                 cmd.args(["--edition", "2018", "--error-format=json"]);
@@ -84,20 +107,28 @@ impl Build {
                 let output = cmd.output()?.stderr;
                 let output = String::from_utf8(output)?;
 
-                let diags = serde_json::Deserializer::from_str(&output).into_iter::<Diagnostic>().collect::<Result<_, _>>()?;
+                let diags = serde_json::Deserializer::from_str(&output)
+                    .into_iter::<Diagnostic>()
+                    .collect::<Result<_, _>>()?;
 
-                let suggestions = rustfix::get_suggestions_from_json(
-                    &output,
+                diags
+            }
+            BuildMode::Script(_) => todo!(),
+        };
+
+        let mut suggestions = Vec::new();
+        for cargo_msg in &diags {
+            // One diagnostic line might have multiple suggestions
+            suggestions.extend(rustfix::collect_suggestions(
+                cargo_msg,
                 &HashSet::new(),
                 rustfix::Filter::Everything,
-                )
-                .context("reading output as rustfix suggestions")?;
+            ));
+        }
 
         Ok((diags, suggestions))
     }
 }
-    }
-}
 
 pub struct BuildResult {
     reproduces_issue: bool,
@@ -114,8 +145,14 @@ impl Display for BuildResult {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match (self.reproduces_issue, self.no_verify) {
             (true, _) => f.write_str("yes"),
-            (false, true) => f.write_str("no (ignore)"),
+            (false, true) => f.write_str("yes (no-verify)"),
             (false, false) => f.write_str("no"),
         }
     }
 }
+
+#[derive(Debug, Deserialize)]
+pub struct CargoJsonCompileMessage {
+    pub reason: String,
+    pub message: Option<Diagnostic>,
+}

src/everybody_loops.rs

@@ -1,14 +1,14 @@
 use quote::ToTokens;
 use syn::{parse_quote, visit_mut::VisitMut};
 
-use crate::processor::{ProcessChecker, Processor};
+use crate::processor::{ProcessChecker, ProcessState, Processor};
 
 struct Visitor<'a> {
     current_path: Vec<String>,
     checker: &'a mut ProcessChecker,
 
     loop_expr: syn::Block,
-    has_made_change: bool,
+    process_state: ProcessState,
 }
 
 impl<'a> Visitor<'a> {
@@ -16,7 +16,7 @@ impl<'a> Visitor<'a> {
         Self {
             current_path: Vec::new(),
             checker,
-            has_made_change: false,
+            process_state: ProcessState::NoChange,
             loop_expr: parse_quote! { { loop {} } },
         }
     }
@@ -30,7 +30,7 @@ impl VisitMut for Visitor<'_> {
             }))] if loop_body.stmts.is_empty() => {}
             _ => {
                 *block = self.loop_expr.clone();
-                self.has_made_change = true;
+                self.process_state = ProcessState::Changed;
             }
         }
     }
@@ -65,10 +65,14 @@ impl VisitMut for Visitor<'_> {
 pub struct EverybodyLoops;
 
 impl Processor for EverybodyLoops {
-    fn process_file(&mut self, krate: &mut syn::File, checker: &mut ProcessChecker) -> bool {
+    fn process_file(
+        &mut self,
+        krate: &mut syn::File,
+        checker: &mut ProcessChecker,
+    ) -> ProcessState {
         let mut visitor = Visitor::new(checker);
         visitor.visit_file_mut(krate);
-        visitor.has_made_change
+        visitor.process_state
     }
 
     fn name(&self) -> &'static str {

src/privatize.rs

@@ -1,16 +1,16 @@
 use syn::{parse_quote, visit_mut::VisitMut, Visibility};
 
-use crate::processor::{ProcessChecker, Processor};
+use crate::processor::{ProcessChecker, Processor, ProcessState};
 
 struct Visitor {
     pub_crate: Visibility,
-    has_made_change: bool,
+    process_state: ProcessState,
 }
 
 impl Visitor {
     fn new() -> Self {
         Self {
-            has_made_change: false,
+            process_state: ProcessState::NoChange,
             pub_crate: parse_quote! { pub(crate) },
         }
     }
@@ -19,7 +19,7 @@ impl Visitor {
 impl VisitMut for Visitor {
     fn visit_visibility_mut(&mut self, vis: &mut Visibility) {
         if let Visibility::Public(_) = vis {
-            self.has_made_change = true;
+            self.process_state = ProcessState::Changed;
             *vis = self.pub_crate.clone();
         }
     }
@@ -29,10 +29,10 @@ impl VisitMut for Visitor {
 pub struct Privatize {}
 
 impl Processor for Privatize {
-    fn process_file(&mut self, krate: &mut syn::File, _: &mut ProcessChecker) -> bool {
+    fn process_file(&mut self, krate: &mut syn::File, _: &mut ProcessChecker) -> ProcessState {
         let mut visitor = Visitor::new();
         visitor.visit_file_mut(krate);
-        visitor.has_made_change
+        visitor.process_state
     }
 
     fn name(&self) -> &'static str {

src/processor/files.rs

@@ -4,7 +4,7 @@ use std::{
     path::{Path, PathBuf},
 };
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq, Hash)]
 pub struct SourceFile {
     pub path: PathBuf,
 }

src/processor/mod.rs

@@ -1,7 +1,7 @@
 mod files;
 mod reaper;
 
-use std::{ffi::OsStr, path::Path};
+use std::{collections::HashSet, ffi::OsStr, path::Path};
 
 use anyhow::{ensure, Context, Result};
 
@@ -10,11 +10,19 @@ use crate::{build::Build, processor::files::Changes, Options};
 use self::files::SourceFile;
 
 pub trait Processor {
-    fn process_file(&mut self, krate: &mut syn::File, checker: &mut ProcessChecker) -> bool;
+    fn process_file(&mut self, krate: &mut syn::File, checker: &mut ProcessChecker)
+        -> ProcessState;
 
     fn name(&self) -> &'static str;
 }
 
+#[derive(Debug, PartialEq, Eq)]
+pub enum ProcessState {
+    NoChange,
+    Changed,
+    FileInvalidated,
+}
+
 #[derive(Debug)]
 pub struct Minimizer {
     files: Vec<SourceFile>,
@@ -61,12 +69,18 @@ impl Minimizer {
             );
         }
 
+        let mut invalidated_files = HashSet::new();
+
         for mut pass in passes {
             'pass: loop {
                 println!("Starting a round of {}", pass.name());
                 let mut changes = Changes::default();
 
                 for file in &self.files {
+                    if invalidated_files.contains(file) {
+                        continue;
+                    }
+
                     let file_display = file.path.display();
 
                     let mut change = file.try_change(&mut changes)?;
@@ -76,7 +90,8 @@ impl Minimizer {
 
                     let has_made_change = pass.process_file(&mut krate, &mut ProcessChecker {});
 
-                    if has_made_change {
+                    match has_made_change {
+                        ProcessState::Changed | ProcessState::FileInvalidated => {
                             let result = prettyplease::unparse(&krate);
 
                             change.write(&result)?;
@@ -90,10 +105,16 @@ impl Minimizer {
                             } else {
                                 change.rollback()?;
                             }
-                    } else {
+
+                            if has_made_change == ProcessState::FileInvalidated {
+                                invalidated_files.insert(file);
+                            }
+                        }
+                        ProcessState::NoChange => {
                             println!("{file_display}: After {}: no change", pass.name());
                         }
                     }
+                }
 
                 if !changes.had_changes() {
                     println!("Finished {}", pass.name());

src/processor/reaper.rs

@@ -1,6 +1,6 @@
 //! Deletes dead code.
 
-use super::{files::Changes, Minimizer, Processor};
+use super::{files::Changes, Minimizer, ProcessState, Processor};
 use anyhow::{ensure, Context, Result};
 use proc_macro2::Span;
 use rustfix::{diagnostics::Diagnostic, Suggestion};
@@ -38,7 +38,10 @@ impl Minimizer {
         // Always unconditionally apply unused imports.
         self.apply_unused_imports(&suggestions_for_file)?;
 
-        self.run_passes([Box::new(DeleteUnusedFunctions(diags)) as Box<dyn Processor>])
+        self.run_passes([Box::new(DeleteUnusedFunctions {
+            diags,
+            invalid: false,
+        }) as Box<dyn Processor>])
             .context("deleting unused functions")?;
 
         Ok(())
@@ -49,11 +52,12 @@ impl Minimizer {
         suggestions: &HashMap<&str, Vec<&Suggestion>>,
     ) -> Result<()> {
         for (file, suggestions) in suggestions {
-            let file = self
+            let Some(file) = self
                 .files
                 .iter()
-                .find(|source| source.path == Path::new(file))
-                .expect("unknown file");
+                .find(|source| source.path == Path::new(file)) else {
+                    continue;
+                };
 
             let mut changes = &mut Changes::default();
 
@@ -85,14 +89,27 @@ impl Minimizer {
     }
 }
 
-struct DeleteUnusedFunctions(Vec<Diagnostic>);
+struct DeleteUnusedFunctions {
+    diags: Vec<Diagnostic>,
+    invalid: bool,
+}
 
 impl Processor for DeleteUnusedFunctions {
-    fn process_file(&mut self, krate: &mut syn::File, _: &mut super::ProcessChecker) -> bool {
-        let mut visitor = FindUnusedFunction::new(self.0.iter());
+    fn process_file(
+        &mut self,
+        krate: &mut syn::File,
+        _: &mut super::ProcessChecker,
+    ) -> ProcessState {
+        assert!(!self.invalid, "processing with invalid state");
+
+        let mut visitor = FindUnusedFunction::new(self.diags.iter());
         visitor.visit_file_mut(krate);
 
-        visitor.has_change
+        if visitor.process_state == ProcessState::FileInvalidated {
+            self.invalid = true;
+        }
+
+        visitor.process_state
     }
 
     fn name(&self) -> &'static str {
@@ -122,7 +139,7 @@ impl Unused {
 
 struct FindUnusedFunction {
     unused_functions: Vec<Unused>,
-    has_change: bool,
+    process_state: ProcessState,
 }
 
 impl FindUnusedFunction {
@@ -160,7 +177,7 @@ impl FindUnusedFunction {
 
         Self {
             unused_functions,
-            has_change: false,
+            process_state: ProcessState::NoChange,
         }
     }
 
@@ -174,11 +191,11 @@ impl FindUnusedFunction {
 
         assert!(
             span_matches < 2,
-            "multiple dead_code spans matched identifier: {span_matches}"
+            "multiple dead_code spans matched identifier: {span_matches}."
         );
 
         if span_matches == 1 {
-            self.has_change = true;
+            self.process_state = ProcessState::FileInvalidated;
         }
 
         span_matches == 0

test-cases/unused-code/Cargo.toml

@@ -4,7 +4,3 @@
 name = "hello-world"
 version = "0.1.0"
 edition = "2021"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]

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

@@ -1,5 +1,8 @@
-fn unused() {}
-
-fn main() {
-    unused();
+fn unused() {
+    loop {}
 }
+fn main() {
+    loop {}
+}
+
+mod other;

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

@@ -0,0 +1,3 @@
+fn unused() {
+    loop {}
+}