Auto merge of #12439 - Jacherr:issue-12185, r=blyxyas

fix ice reporting in lintcheck

Fixes https://github.com/rust-lang/rust-clippy/issues/12185

This PR fixes the lack of reported ICEs within lintcheck by modifying the way in which data is collected from each crate being linted.

Instead of lintcheck only reading `stdout` for warnings, it now also reads `stderr` for any potential ICE (although admittedly, it is not the cleanest method of doing so). If it is detected, it parses the ICE into its message and backtrace separately, and then adds them to the list of outputs via clippy.

Once all outputs are collected, the formatter then proceeds to generate the file as normal.

Note that this PR also has a couple of side effects:
- When clippy fails to process a package, but said failure is not an ICE, the `stderr` will be sent to the console;
- Instead of `ClippyWarning` being the primary struct for everything reported, there is now `ClippyCheckOutput`, an enum which splits the outputs into warnings and ICEs.

changelog: none

lintcheck/src/main.rs

@@ -26,12 +26,12 @@
 use std::fmt::{self, Write as _};
 use std::io::{self, ErrorKind};
 use std::path::{Path, PathBuf};
-use std::process::Command;
+use std::process::{Command, ExitStatus};
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::time::Duration;
 use std::{env, fs, thread};
 
-use cargo_metadata::diagnostic::{Diagnostic, DiagnosticLevel};
+use cargo_metadata::diagnostic::Diagnostic;
 use cargo_metadata::Message;
 use rayon::prelude::*;
 use serde::{Deserialize, Serialize};
@@ -97,16 +97,43 @@ struct Crate {
     options: Option<Vec<String>>,
 }
 
+/// A single emitted output from clippy being executed on a crate. It may either be a
+/// `ClippyWarning`, or a `RustcIce` caused by a panic within clippy. A crate may have many
+/// `ClippyWarning`s but a maximum of one `RustcIce` (at which point clippy halts execution).
+#[derive(Debug)]
+enum ClippyCheckOutput {
+    ClippyWarning(ClippyWarning),
+    RustcIce(RustcIce),
+}
+
+#[derive(Debug)]
+struct RustcIce {
+    pub crate_name: String,
+    pub ice_content: String,
+}
+impl RustcIce {
+    pub fn from_stderr_and_status(crate_name: &str, status: ExitStatus, stderr: &str) -> Option<Self> {
+        if status.code().unwrap_or(0) == 101
+        /* ice exit status */
+        {
+            Some(Self {
+                crate_name: crate_name.to_owned(),
+                ice_content: stderr.to_owned(),
+            })
+        } else {
+            None
+        }
+    }
+}
+
 /// A single warning that clippy issued while checking a `Crate`
 #[derive(Debug)]
 struct ClippyWarning {
-    crate_name: String,
     file: String,
     line: usize,
     column: usize,
     lint_type: String,
     message: String,
-    is_ice: bool,
 }
 
 #[allow(unused)]
@@ -131,13 +158,11 @@ fn new(diag: Diagnostic, crate_name: &str, crate_version: &str) -> Option<Self>
         };
 
         Some(Self {
-            crate_name: crate_name.to_owned(),
             file,
             line: span.line_start,
             column: span.column_start,
             lint_type,
             message: diag.message,
-            is_ice: diag.level == DiagnosticLevel::Ice,
         })
     }
 
@@ -318,7 +343,7 @@ fn run_clippy_lints(
         config: &LintcheckConfig,
         lint_filter: &[String],
         server: &Option<LintcheckServer>,
-    ) -> Vec<ClippyWarning> {
+    ) -> Vec<ClippyCheckOutput> {
         // advance the atomic index by one
         let index = target_dir_index.fetch_add(1, Ordering::SeqCst);
         // "loop" the index within 0..thread_limit
@@ -342,9 +367,9 @@ fn run_clippy_lints(
         let shared_target_dir = clippy_project_root().join("target/lintcheck/shared_target_dir");
 
         let mut cargo_clippy_args = if config.fix {
-            vec!["--fix", "--"]
+            vec!["--quiet", "--fix", "--"]
         } else {
-            vec!["--", "--message-format=json", "--"]
+            vec!["--quiet", "--message-format=json", "--"]
         };
 
         let mut clippy_args = Vec::<&str>::new();
@@ -435,14 +460,21 @@ fn run_clippy_lints(
         }
 
         // get all clippy warnings and ICEs
-        let warnings: Vec<ClippyWarning> = Message::parse_stream(stdout.as_bytes())
+        let mut entries: Vec<ClippyCheckOutput> = Message::parse_stream(stdout.as_bytes())
             .filter_map(|msg| match msg {
                 Ok(Message::CompilerMessage(message)) => ClippyWarning::new(message.message, &self.name, &self.version),
                 _ => None,
             })
+            .map(ClippyCheckOutput::ClippyWarning)
             .collect();
 
-        warnings
+        if let Some(ice) = RustcIce::from_stderr_and_status(&self.name, *status, &stderr) {
+            entries.push(ClippyCheckOutput::RustcIce(ice));
+        } else if !status.success() {
+            println!("non-ICE bad exit status for {} {}: {}", self.name, self.version, stderr);
+        }
+
+        entries
     }
 }
 
@@ -642,7 +674,7 @@ fn main() {
         LintcheckServer::spawn(recursive_options)
     });
 
-    let mut clippy_warnings: Vec<ClippyWarning> = crates
+    let mut clippy_entries: Vec<ClippyCheckOutput> = crates
         .par_iter()
         .flat_map(|krate| {
             krate.run_clippy_lints(
@@ -658,7 +690,9 @@ fn main() {
         .collect();
 
     if let Some(server) = server {
-        clippy_warnings.extend(server.warnings());
+        let server_clippy_entries = server.warnings().map(ClippyCheckOutput::ClippyWarning);
+
+        clippy_entries.extend(server_clippy_entries);
     }
 
     // if we are in --fix mode, don't change the log files, terminate here
@@ -666,20 +700,21 @@ fn main() {
         return;
     }
 
+    // split up warnings and ices
+    let mut warnings: Vec<ClippyWarning> = vec![];
+    let mut raw_ices: Vec<RustcIce> = vec![];
+    for entry in clippy_entries {
+        if let ClippyCheckOutput::ClippyWarning(x) = entry {
+            warnings.push(x);
+        } else if let ClippyCheckOutput::RustcIce(x) = entry {
+            raw_ices.push(x);
+        }
+    }
+
     // generate some stats
-    let (stats_formatted, new_stats) = gather_stats(&clippy_warnings);
+    let (stats_formatted, new_stats) = gather_stats(&warnings);
 
-    // grab crashes/ICEs, save the crate name and the ice message
-    let ices: Vec<(&String, &String)> = clippy_warnings
-        .iter()
-        .filter(|warning| warning.is_ice)
-        .map(|w| (&w.crate_name, &w.message))
-        .collect();
-
-    let mut all_msgs: Vec<String> = clippy_warnings
-        .iter()
-        .map(|warn| warn.to_output(config.markdown))
-        .collect();
+    let mut all_msgs: Vec<String> = warnings.iter().map(|warn| warn.to_output(config.markdown)).collect();
     all_msgs.sort();
     all_msgs.push("\n\n### Stats:\n\n".into());
     all_msgs.push(stats_formatted);
@@ -693,11 +728,18 @@ fn main() {
     }
     write!(text, "{}", all_msgs.join("")).unwrap();
     text.push_str("\n\n### ICEs:\n");
-    for (cratename, msg) in &ices {
-        let _: fmt::Result = write!(text, "{cratename}: '{msg}'");
+    for ice in &raw_ices {
+        let _: fmt::Result = write!(
+            text,
+            "{}:\n{}\n========================================\n\n",
+            ice.crate_name, ice.ice_content
+        );
     }
 
     println!("Writing logs to {}", config.lintcheck_results_path.display());
+    if !raw_ices.is_empty() {
+        println!("WARNING: at least one ICE reported, check log file");
+    }
     fs::create_dir_all(config.lintcheck_results_path.parent().unwrap()).unwrap();
     fs::write(&config.lintcheck_results_path, text).unwrap();