[llvm] bf40125 - [Signal] Re-raise SIGPIPE if the handler is uninstalled

[Vedant Kumar via llvm-commits]

Author: Vedant Kumar
Date: 2021-01-08T11:13:43-08:00
New Revision: bf401256edd00e921a5d3a0bf4cf6ee66ae51cd6

URL: https://github.com/llvm/llvm-project/commit/bf401256edd00e921a5d3a0bf4cf6ee66ae51cd6
DIFF: https://github.com/llvm/llvm-project/commit/bf401256edd00e921a5d3a0bf4cf6ee66ae51cd6.diff

LOG: [Signal] Re-raise SIGPIPE if the handler is uninstalled

Instead of falling through to RunSignalHandlers after the SIGPIPE
handler is uninstalled and we get a SIGPIPE, re-raise the signal, just
like we do for other IntSigs.

This was discussed and informally OK'd here:

https://reviews.llvm.org/rG9a3f892d018238dce5181e458905311db8e682f5#856804

Added: 
    

Modified: 
    llvm/lib/Support/Unix/Signals.inc

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Support/Unix/Signals.inc b/llvm/lib/Support/Unix/Signals.inc
index 1ac2e090dcb8..3d7b5d2fe5aa 100644
--- a/llvm/lib/Support/Unix/Signals.inc
+++ b/llvm/lib/Support/Unix/Signals.inc
@@ -382,13 +382,15 @@ static RETSIGTYPE SignalHandler(int Sig) {
               OneShotPipeSignalFunction.exchange(nullptr))
         return OldOneShotPipeFunction();
 
-    if (llvm::is_contained(IntSigs, Sig)) {
+    bool IsIntSig = llvm::is_contained(IntSigs, Sig);
+    if (IsIntSig)
       if (auto OldInterruptFunction = InterruptFunction.exchange(nullptr))
         return OldInterruptFunction();
 
-      raise(Sig);   // Execute the default handler.
+    if (Sig == SIGPIPE || IsIntSig) {
+      raise(Sig); // Execute the default handler.
       return;
-   }
+    }
   }
 
   // Otherwise if it is a fault (like SEGV) run any handler.