Rollup merge of #115280 - RalfJung:panic-cleanup-triple-backtrace, r=Amanieu

avoid triple-backtrace due to panic-during-cleanup

Supersedes https://github.com/rust-lang/rust/pull/115020
Cc https://github.com/rust-lang/rust/issues/114954
r? ``@Amanieu``

1 files changed, 30 insertions, 6 deletions

diff --git a/library/std/src/panicking.rs b/library/std/src/panicking.rs
index 6ff7b19f293..b20e5464e6e 100644
--- a/library/std/src/panicking.rs
+++ b/library/std/src/panicking.rs
@@ -246,7 +246,9 @@ fn default_hook(info: &PanicInfo<'_>) {
 pub fn panic_hook_with_disk_dump(info: &PanicInfo<'_>, path: Option<&crate::path::Path>) {
     // If this is a double panic, make sure that we print a backtrace
     // for this panic. Otherwise only print it if logging is enabled.
-    let backtrace = if panic_count::get_count() >= 2 {
+    let backtrace = if info.force_no_backtrace() {
+        None
+    } else if panic_count::get_count() >= 2 {
         BacktraceStyle::full()
     } else {
         crate::panic::get_backtrace_style()
@@ -294,7 +296,7 @@ pub fn panic_hook_with_disk_dump(info: &PanicInfo<'_>, path: Option<&crate::path
                     }
                 }
             }
-            // If backtraces aren't supported, do nothing.
+            // If backtraces aren't supported or are forced-off, do nothing.
             None => {}
         }
     };
@@ -615,14 +617,23 @@ pub fn begin_panic_handler(info: &PanicInfo<'_>) -> ! {
     let loc = info.location().unwrap(); // The current implementation always returns Some
     let msg = info.message().unwrap(); // The current implementation always returns Some
     crate::sys_common::backtrace::__rust_end_short_backtrace(move || {
+        // FIXME: can we just pass `info` along rather than taking it apart here, only to have
+        // `rust_panic_with_hook` construct a new `PanicInfo`?
         if let Some(msg) = msg.as_str() {
-            rust_panic_with_hook(&mut StrPanicPayload(msg), info.message(), loc, info.can_unwind());
+            rust_panic_with_hook(
+                &mut StrPanicPayload(msg),
+                info.message(),
+                loc,
+                info.can_unwind(),
+                info.force_no_backtrace(),
+            );
         } else {
             rust_panic_with_hook(
                 &mut PanicPayload::new(msg),
                 info.message(),
                 loc,
                 info.can_unwind(),
+                info.force_no_backtrace(),
             );
         }
     })
@@ -647,7 +658,13 @@ pub const fn begin_panic<M: Any + Send>(msg: M) -> ! {
 
     let loc = Location::caller();
     return crate::sys_common::backtrace::__rust_end_short_backtrace(move || {
-        rust_panic_with_hook(&mut PanicPayload::new(msg), None, loc, true)
+        rust_panic_with_hook(
+            &mut PanicPayload::new(msg),
+            None,
+            loc,
+            /* can_unwind */ true,
+            /* force_no_backtrace */ false,
+        )
     });
 
     struct PanicPayload<A> {
@@ -693,6 +710,7 @@ fn rust_panic_with_hook(
     message: Option<&fmt::Arguments<'_>>,
     location: &Location<'_>,
     can_unwind: bool,
+    force_no_backtrace: bool,
 ) -> ! {
     let must_abort = panic_count::increase(true);
 
@@ -707,14 +725,20 @@ fn rust_panic_with_hook(
             panic_count::MustAbort::AlwaysAbort => {
                 // Unfortunately, this does not print a backtrace, because creating
                 // a `Backtrace` will allocate, which we must to avoid here.
-                let panicinfo = PanicInfo::internal_constructor(message, location, can_unwind);
+                let panicinfo = PanicInfo::internal_constructor(
+                    message,
+                    location,
+                    can_unwind,
+                    force_no_backtrace,
+                );
                 rtprintpanic!("{panicinfo}\npanicked after panic::always_abort(), aborting.\n");
             }
         }
         crate::sys::abort_internal();
     }
 
-    let mut info = PanicInfo::internal_constructor(message, location, can_unwind);
+    let mut info =
+        PanicInfo::internal_constructor(message, location, can_unwind, force_no_backtrace);
     let hook = HOOK.read().unwrap_or_else(PoisonError::into_inner);
     match *hook {
         // Some platforms (like wasm) know that printing to stderr won't ever actually