Bugpoint support for miscompilations that result in a crash.

This change allows bugpoint to pinpoint the "opt" pass and bitcode
segment responsible for a crash caused by miscompilation. At least it
works well for me now, without having to create any custom execution
wrappers.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131186 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 16 insertions, 2 deletions

diff --git a/tools/bugpoint/ToolRunner.cpp b/tools/bugpoint/ToolRunner.cpp
index 6c46ef18eb..9c3e6121f2 100644
--- a/tools/bugpoint/ToolRunner.cpp
+++ b/tools/bugpoint/ToolRunner.cpp
@@ -50,6 +50,11 @@ namespace {
           cl::desc("Remote execution (rsh/ssh) extra options"));
 }
 
+// Add a prefix to ErrMsg if the program is terminated by a signal to
+// distinguish compiled program crashes from other execution
+// failures. Miscompilation likely to results in SIGSEGV.
+static const char *SignalPrefix = "Signal - ";
+
 /// RunProgramWithTimeout - This function provides an alternate interface
 /// to the sys::Program::ExecuteAndWait interface.
 /// @see sys::Program::ExecuteAndWait
@@ -77,7 +82,7 @@ static int RunProgramWithTimeout(const sys::Path &ProgramPath,
 
   return
     sys::Program::ExecuteAndWait(ProgramPath, Args, 0, redirects,
-                                 NumSeconds, MemoryLimit, ErrMsg);
+                                 NumSeconds, MemoryLimit, ErrMsg, SignalPrefix);
 }
 
 /// RunProgramRemotelyWithTimeout - This function runs the given program
@@ -854,9 +859,18 @@ int GCC::ExecuteProgram(const std::string &ProgramFile,
 
   if (RemoteClientPath.isEmpty()) {
     DEBUG(errs() << "<run locally>");
-    return RunProgramWithTimeout(OutputBinary, &ProgramArgs[0],
+    int ExitCode = RunProgramWithTimeout(OutputBinary, &ProgramArgs[0],
         sys::Path(InputFile), sys::Path(OutputFile), sys::Path(OutputFile),
         Timeout, MemoryLimit, Error);
+    // Treat a signal (usually SIGSEGV) as part of the program output so that
+    // crash-causing miscompilation is handled seamlessly.
+    if (Error->find(SignalPrefix) == 0) {
+      std::ofstream outFile(OutputFile.c_str(), std::ios_base::app);
+      outFile << *Error << '\n';
+      outFile.close();
+      Error->clear();
+    }
+    return ExitCode;
   } else {
     outs() << "<run remotely>"; outs().flush();
     return RunProgramRemotelyWithTimeout(sys::Path(RemoteClientPath),