Revert "Reapply: Add an error message to the default SIGPIPE handler"

This patch is spamming compiles with unhelpful and confusing messages.
E.g. the Linux kernel uses "grep -q" in several places. It's meant to
quit with a return code of zero when the first match is found. This can
cause a SIGPIPE signal, but that's expected, and there's no way to turn
this error message off to avoid spurious error messages.

UNIX03 apparently doesn't require printing an error message on SIGPIPE,
but specifically when there's an error on the stdout stream in a normal
program flow, e.g. when SIGPIPE trap is disabled.

A separate patch is planned to address the specific case we care most
about (involving llvm-nm).

This reverts commit b89bcefa6202e310eb3167dd1c37f1807377ec8d.

Link: https://github.com/llvm/llvm-project/issues/59037
Link: https://github.com/ClangBuiltLinux/linux/issues/1651

Differential Revision: https://reviews.llvm.org/D138244

1 files changed, 0 insertions, 4 deletions

diff --git a/llvm/lib/Support/Unix/Signals.inc b/llvm/lib/Support/Unix/Signals.inc
index 3c34da8f..b07d319 100644
--- a/llvm/lib/Support/Unix/Signals.inc
+++ b/llvm/lib/Support/Unix/Signals.inc
@@ -432,10 +432,6 @@ void llvm::sys::SetOneShotPipeSignalFunction(void (*Handler)()) {
 }
 
 void llvm::sys::DefaultOneShotPipeSignalHandler() {
-  // UNIX03 conformance requires a non-zero exit code and an error message
-  // to stderr when writing to a closed stdout fails.
-  errs() << "error: write on a pipe with no reader\n";
-
   // Send a special return code that drivers can check for, from sysexits.h.
   exit(EX_IOERR);
 }