Merge #7047

7047: Add force_show_panics flag for proc-macro bridge r=jonas-schievink a=edwin0cheng

https://github.com/rust-lang/rust/pull/75082 and https://github.com/rust-lang/rust/pull/76292 added a new flag in `proc_macro::Bridge` such that the ABI was changed. These ABI changing are the reason of some weird panics which caused #6880 and maybe related to the panic mentioned in #6820.

These changes are landed on rust stable 1.48 so I think it is okay to apply it now.

fixes #6880

r @jonas-schievink 


Co-authored-by: Edwin Cheng <[email protected]>

1 files changed, 8 insertions, 4 deletions

diff --git a/crates/proc_macro_srv/src/proc_macro/bridge/client.rs b/crates/proc_macro_srv/src/proc_macro/bridge/client.rs
index 55d6330cc..ca6749b9b 100644
--- a/crates/proc_macro_srv/src/proc_macro/bridge/client.rs
+++ b/crates/proc_macro_srv/src/proc_macro/bridge/client.rs
@@ -303,17 +303,21 @@ impl BridgeState<'_> {
 
 impl Bridge<'_> {
     fn enter<R>(self, f: impl FnOnce() -> R) -> R {
+        let force_show_panics = self.force_show_panics;
+
         // Hide the default panic output within `proc_macro` expansions.
         // NB. the server can't do this because it may use a different libstd.
         static HIDE_PANICS_DURING_EXPANSION: Once = Once::new();
         HIDE_PANICS_DURING_EXPANSION.call_once(|| {
             let prev = panic::take_hook();
             panic::set_hook(Box::new(move |info| {
-                let hide = BridgeState::with(|state| match state {
-                    BridgeState::NotConnected => false,
-                    BridgeState::Connected(_) | BridgeState::InUse => true,
+                let show = BridgeState::with(|state| match state {
+                    BridgeState::NotConnected => true,
+                    // Something weird is going on, so don't suppress any backtraces
+                    BridgeState::InUse => true,
+                    BridgeState::Connected(bridge) => force_show_panics,
                 });
-                if !hide {
+                if show {
                     prev(info)
                 }
             }));