Don't PrintOnPanic on fatal errors

Author: bjorn3

src/base.rs

@@ -29,8 +29,9 @@ pub(crate) fn codegen_and_compile_fn<'tcx>(
     module: &mut dyn Module,
     instance: Instance<'tcx>,
 ) {
-    let _inst_guard =
-        crate::PrintOnPanic(|| format!("{:?} {}", instance, tcx.symbol_name(instance).name));
+    let _inst_guard = crate::PrintOnPanic(Some(tcx.sess), || {
+        format!("{:?} {}", instance, tcx.symbol_name(instance).name)
+    });
 
     let cached_func = std::mem::replace(&mut cached_context.func, Function::new());
     let codegened_func = codegen_fn(tcx, cx, cached_func, module, instance);
@@ -48,7 +49,7 @@ pub(crate) fn codegen_fn<'tcx>(
     debug_assert!(!instance.substs.needs_infer());
 
     let mir = tcx.instance_mir(instance.def);
-    let _mir_guard = crate::PrintOnPanic(|| {
+    let _mir_guard = crate::PrintOnPanic(Some(tcx.sess), || {
         let mut buf = Vec::new();
         with_no_trimmed_paths!({
             rustc_middle::mir::pretty::write_mir_fn(tcx, mir, &mut |_, _| Ok(()), &mut buf)
@@ -176,7 +177,7 @@ pub(crate) fn compile_fn(
             write!(clif, " {}", isa_flag).unwrap();
         }
         writeln!(clif, "\n").unwrap();
-        crate::PrintOnPanic(move || {
+        crate::PrintOnPanic(None, move || {
             let mut clif = clif.clone();
             ::cranelift_codegen::write::decorate_function(
                 &mut &clif_comments_clone,
@@ -497,7 +498,7 @@ fn codegen_stmt<'tcx>(
     #[allow(unused_variables)] cur_block: Block,
     stmt: &Statement<'tcx>,
 ) {
-    let _print_guard = crate::PrintOnPanic(|| format!("stmt {:?}", stmt));
+    let _print_guard = crate::PrintOnPanic(Some(fx.tcx.sess), || format!("stmt {:?}", stmt));
 
     fx.set_debug_loc(stmt.source_info);
 

src/driver/mod.rs

@@ -23,7 +23,8 @@ fn predefine_mono_items<'tcx>(
             match mono_item {
                 MonoItem::Fn(instance) => {
                     let name = tcx.symbol_name(instance).name;
-                    let _inst_guard = crate::PrintOnPanic(|| format!("{:?} {}", instance, name));
+                    let _inst_guard =
+                        crate::PrintOnPanic(Some(tcx.sess), || format!("{:?} {}", instance, name));
                     let sig =
                         get_function_sig(tcx, module.target_config().default_call_conv, instance);
                     let linkage = crate::linkage::get_clif_linkage(

src/lib.rs

@@ -113,11 +113,11 @@ mod prelude {
     pub(crate) use crate::value_and_place::{CPlace, CPlaceInner, CValue};
 }
 
-struct PrintOnPanic<F: Fn() -> String>(F);
-impl<F: Fn() -> String> Drop for PrintOnPanic<F> {
+struct PrintOnPanic<'a, F: Fn() -> String>(Option<&'a Session>, F);
+impl<'a, F: Fn() -> String> Drop for PrintOnPanic<'a, F> {
     fn drop(&mut self) {
-        if ::std::thread::panicking() {
-            println!("{}", (self.0)());
+        if ::std::thread::panicking() && self.0.map_or(true, |sess| sess.has_errors().is_none()) {
+            println!("{}", (self.1)());
         }
     }
 }