Revert 344389 "Revert r344375 "[Driver] check for exit code from SIGPIPE""

[nickdesaulniers]

Summary

Add preprocessor guards for UNIX.

This reverts commit r344389.

[rnk]

I think it's fine, just remove the git hash from the commit message and just refer to the svn number.

[nickdesaulniers]

I think this is now breaking:
lld :: ELF/format-binary.test
lld :: ELF/relocatable-versioned.s

[nickdesaulniers]

Nevermind, looks like flaky tests. Will try to repro and contact msan maintainers.

[richard.barton.arm]

Hi @nickdesaulniers
I have run into this too recently so would love to see this patch land. Did you get anywhere with those lld test failures?
Ta
Rich

[nickdesaulniers]

Hi @richard.barton.arm , this has landed already. If you click "show older" you'll see the UI element that shows this landed as r344536 (Oct 15 2018). If your clang version is later than r344536 (what will become clang-8) and you still see this, please open a new bug. The commit is definitely confusing; it looks like a revert, but it's a revert of a revert (double negative) which is relanding the patch. The lld failures were PEBKAC on my part, unrelated to this patch.

[richard.barton.arm]

Hi @nickdesaulniers - thanks for the clarification. I was suffering from some PEBCAK of my own when I thought the commits were not on master. Thanks for these patches - a great help.

lib/Driver/Driver.cpp

 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Support/raw_ostream.h"
 #include <map>
 #include <memory>
 #include <utility>
 #if LLVM_ON_UNIX
 #include <unistd.h> // getpid
+#include <sysexits.h> // EX_IOERR
 #endif
 
 using namespace clang::driver;
 using namespace clang;
 using namespace llvm::opt;
 
 Driver::Driver(StringRef ClangExecutable, StringRef TargetTriple,
                DiagnosticsEngine &Diags,
int Driver::ExecuteCompilation(
   C.ExecuteJobs(C.getJobs(), FailingCommands);
 
   // If the command succeeded, we are done.
   if (FailingCommands.empty())
     return 0;
 
   // Otherwise, remove result files and print extra information about abnormal
   // failures.
+  int Res = 0;
   for (const auto &CmdPair : FailingCommands) {
-    int Res = CmdPair.first;
+    int CommandRes = CmdPair.first;
     const Command *FailingCommand = CmdPair.second;
 
     // Remove result files if we're not saving temps.
     if (!isSaveTempsEnabled()) {
       const JobAction *JA = cast<JobAction>(&FailingCommand->getSource());
       C.CleanupFileMap(C.getResultFiles(), JA, true);
 
       // Failure result files are valid unless we crashed.
-      if (Res < 0)
+      if (CommandRes < 0)
         C.CleanupFileMap(C.getFailureResultFiles(), JA, true);
     }
 
+#if LLVM_ON_UNIX
+    // llvm/lib/Support/Unix/Signals.inc will exit with a special return code
+    // for SIGPIPE. Do not print diagnostics for this case.
+    if (CommandRes == EX_IOERR) {
+      Res = CommandRes;
+      continue;
+    }
+#endif
+
     // Print extra information about abnormal failures, if possible.
     //
     // This is ad-hoc, but we don't want to be excessively noisy. If the result
     // status was 1, assume the command failed normally. In particular, if it
     // was the compiler then assume it gave a reasonable error code. Failures
     // in other tools are less common, and they generally have worse
     // diagnostics, so always print the diagnostic there.
     const Tool &FailingTool = FailingCommand->getCreator();
 
-    if (!FailingCommand->getCreator().hasGoodDiagnostics() || Res != 1) {
+    if (!FailingCommand->getCreator().hasGoodDiagnostics() || CommandRes != 1) {
       // FIXME: See FIXME above regarding result code interpretation.
-      if (Res < 0)
+      if (CommandRes < 0)
         Diag(clang::diag::err_drv_command_signalled)
             << FailingTool.getShortName();
       else
-        Diag(clang::diag::err_drv_command_failed) << FailingTool.getShortName()
-                                                  << Res;
+        Diag(clang::diag::err_drv_command_failed)
+            << FailingTool.getShortName() << CommandRes;
     }
   }
-  return 0;
+  return Res;
 }
 
 void Driver::PrintHelp(bool ShowHidden) const {
   unsigned IncludedFlagsBitmask;
   unsigned ExcludedFlagsBitmask;
   std::tie(IncludedFlagsBitmask, ExcludedFlagsBitmask) =
       getIncludeExcludeOptionFlagMasks();