[Clang][Driver] After default -fintegrated-cc1, make llvm::report_fatal_error() generate preprocessed source + reproducer.sh again.

Added a test for #pragma clang __debug llvm_fatal_error to test for the original issue.
Added llvm::sys::Process::Exit() and replaced ::exit() in places where it was appropriate. This new function would call the current CrashRecoveryContext if one is running on the same thread; or call ::exit() otherwise.

Fixes PR44705.

Differential Revision: https://reviews.llvm.org/D73742

clang/test/Driver/crash-report.c

@@ -21,12 +21,20 @@
 // RUN: cat %t/crash-report-*.c | FileCheck --check-prefix=CHECKSRC %s
 // RUN: cat %t/crash-report-*.sh | FileCheck --check-prefix=CHECKSH %s
 
+// RUN: env TMPDIR=%t TEMP=%t TMP=%t RC_DEBUG_OPTIONS=1                  \
+// RUN:  CC_PRINT_HEADERS=1 CC_LOG_DIAGNOSTICS=1                         \
+// RUN:  not %clang %s @%t.rsp -DFATAL 2>&1 | FileCheck %s
+// RUN: cat %t/crash-report-*.c | FileCheck --check-prefix=CHECKSRC %s
+// RUN: cat %t/crash-report-*.sh | FileCheck --check-prefix=CHECKSH %s
+
 // REQUIRES: crash-recovery
 
 #ifdef PARSER
 #pragma clang __debug parser_crash
 #elif CRASH
 #pragma clang __debug crash
+#elif FATAL
+#pragma clang __debug llvm_fatal_error
 #endif
 
 // CHECK: Preprocessed source(s) and associated run script(s) are located at:

clang/tools/driver/cc1_main.cpp

@@ -36,6 +36,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/Process.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/TargetSelect.h"
@@ -69,7 +70,7 @@ static void LLVMErrorHandler(void *UserData, const std::string &Message,
   // We cannot recover from llvm errors.  When reporting a fatal error, exit
   // with status 70 to generate crash diagnostics.  For BSD systems this is
   // defined as an internal software error.  Otherwise, exit with status 1.
-  exit(GenCrashDiag ? 70 : 1);
+  llvm::sys::Process::Exit(GenCrashDiag ? 70 : 1);
 }
 
 #ifdef CLANG_HAVE_RLIMITS

clang/tools/driver/cc1as_main.cpp

@@ -46,6 +46,7 @@
 #include "llvm/Support/Host.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/Process.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/TargetRegistry.h"
@@ -555,7 +556,7 @@ static void LLVMErrorHandler(void *UserData, const std::string &Message,
   Diags.Report(diag::err_fe_error_backend) << Message;
 
   // We cannot recover from llvm errors.
-  exit(1);
+  sys::Process::Exit(1);
 }
 
 int cc1as_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {

llvm/include/llvm/Support/CrashRecoveryContext.h

@@ -97,6 +97,11 @@ public:
     return RunSafelyOnThread([&]() { Fn(UserData); }, RequestedStackSize);
   }
 
+  /// Explicitly trigger a crash recovery in the current process, and
+  /// return failure from RunSafely(). This function does not return.
+  LLVM_ATTRIBUTE_NORETURN
+  void HandleExit(int RetCode);
+
   /// In case of a crash, this is the crash identifier.
   int RetCode = 0;
 

llvm/include/llvm/Support/Process.h

@@ -201,6 +201,12 @@ public:
   /// Get the result of a process wide random number generator. The
   /// generator will be automatically seeded in non-deterministic fashion.
   static unsigned GetRandomNumber();
+
+  /// Equivalent to ::exit(), except when running inside a CrashRecoveryContext.
+  /// In that case, the control flow will resume after RunSafely(), like for a
+  /// crash, rather than exiting the current process.
+  LLVM_ATTRIBUTE_NORETURN
+  static void Exit(int RetCode);
 };
 
 }

llvm/lib/Support/CrashRecoveryContext.cpp

@@ -14,9 +14,6 @@
 #include "llvm/Support/ThreadLocal.h"
 #include <mutex>
 #include <setjmp.h>
-#ifdef _WIN32
-#include <windows.h> // for GetExceptionInformation
-#endif
 #if LLVM_ON_UNIX
 #include <sysexits.h> // EX_IOERR
 #endif
@@ -178,6 +175,9 @@ CrashRecoveryContext::unregisterCleanup(CrashRecoveryContextCleanup *cleanup) {
 }
 
 #if defined(_MSC_VER)
+
+#include <windows.h> // for GetExceptionInformation
+
 // If _MSC_VER is defined, we must have SEH. Use it if it's available. It's way
 // better than VEH. Vectored exception handling catches all exceptions happening
 // on the thread with installed exception handlers, so it can interfere with
@@ -203,6 +203,8 @@ static int ExceptionFilter(_EXCEPTION_POINTERS *Except) {
   }
 
   int RetCode = (int)Except->ExceptionRecord->ExceptionCode;
+  if ((RetCode & 0xF0000000) == 0xE0000000)
+    RetCode &= ~0xF0000000; // this crash was generated by sys::Process::Exit
 
   // Handle the crash
   const_cast<CrashRecoveryContextImpl *>(CRCI)->HandleCrash(
@@ -280,10 +282,13 @@ static LONG CALLBACK ExceptionHandler(PEXCEPTION_POINTERS ExceptionInfo)
   // TODO: We can capture the stack backtrace here and store it on the
   // implementation if we so choose.
 
+  int RetCode = (int)ExceptionInfo->ExceptionRecord->ExceptionCode;
+  if ((RetCode & 0xF0000000) == 0xE0000000)
+    RetCode &= ~0xF0000000; // this crash was generated by sys::Process::Exit
+
   // Handle the crash
   const_cast<CrashRecoveryContextImpl *>(CRCI)->HandleCrash(
-      (int)ExceptionInfo->ExceptionRecord->ExceptionCode,
-      reinterpret_cast<uintptr_t>(ExceptionInfo));
+      RetCode, reinterpret_cast<uintptr_t>(ExceptionInfo));
 
   // Note that we don't actually get here because HandleCrash calls
   // longjmp, which means the HandleCrash function never returns.
@@ -416,6 +421,21 @@ bool CrashRecoveryContext::RunSafely(function_ref<void()> Fn) {
 
 #endif // !_MSC_VER
 
+LLVM_ATTRIBUTE_NORETURN
+void CrashRecoveryContext::HandleExit(int RetCode) {
+#if defined(_WIN32)
+  // SEH and VEH
+  ::RaiseException(0xE0000000 | RetCode, 0, 0, NULL);
+#else
+  // On Unix we don't need to raise an exception, we go directly to
+  // HandleCrash(), then longjmp will unwind the stack for us.
+  CrashRecoveryContextImpl *CRCI = (CrashRecoveryContextImpl *)Impl;
+  assert(CRCI && "Crash recovery context never initialized!");
+  CRCI->HandleCrash(RetCode, 0 /*no sig num*/);
+#endif
+  llvm_unreachable("Most likely setjmp wasn't called!");
+}
+
 // FIXME: Portability.
 static void setThreadBackgroundPriority() {
 #ifdef __APPLE__

llvm/lib/Support/ErrorHandling.cpp

@@ -19,6 +19,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/Error.h"
+#include "llvm/Support/Process.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/Threading.h"
 #include "llvm/Support/WindowsError.h"
@@ -122,7 +123,7 @@ void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) {
   // files registered with RemoveFileOnSignal.
   sys::RunInterruptHandlers();
 
-  exit(1);
+  sys::Process::Exit(1);
 }
 
 void llvm::install_bad_alloc_error_handler(fatal_error_handler_t handler,

llvm/lib/Support/Process.cpp

@@ -13,8 +13,9 @@
 #include "llvm/Support/Process.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
-#include "llvm/Config/llvm-config.h"
 #include "llvm/Config/config.h"
+#include "llvm/Config/llvm-config.h"
+#include "llvm/Support/CrashRecoveryContext.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Program.h"
@@ -88,6 +89,13 @@ static bool coreFilesPrevented = !LLVM_ENABLE_CRASH_DUMPS;
 
 bool Process::AreCoreFilesPrevented() { return coreFilesPrevented; }
 
+LLVM_ATTRIBUTE_NORETURN
+void Process::Exit(int RetCode) {
+  if (CrashRecoveryContext *CRC = CrashRecoveryContext::GetCurrent())
+    CRC->HandleExit(RetCode);
+  ::exit(RetCode);
+}
+
 // Include the platform-specific parts of this class.
 #ifdef LLVM_ON_UNIX
 #include "Unix/Process.inc"