Index: clang/include/clang/Driver/Driver.h
===================================================================
--- clang/include/clang/Driver/Driver.h
+++ clang/include/clang/Driver/Driver.h
@@ -505,6 +505,31 @@
       StringRef AdditionalInformation = "",
       CompilationDiagnosticReport *GeneratedReport = nullptr);
 
+  enum class CommandStatus {
+    Crash = 1,
+    Error,
+    Ok,
+  };
+
+  enum class ReproLevel {
+    Off = 0,
+    OnCrash = static_cast<int>(CommandStatus::Crash),
+    OnError = static_cast<int>(CommandStatus::Error),
+    Always = static_cast<int>(CommandStatus::Ok),
+  };
+
+  void generateCompilationDiagnosticsIfNecessary(
+      CommandStatus CS, ReproLevel Level, Compilation &C,
+      const Command &FailingCommand, StringRef AdditionalInformation = "",
+      CompilationDiagnosticReport *GeneratedReport = nullptr) {
+    if (static_cast<int>(CS) > static_cast<int>(Level))
+      return;
+    // Hack to ensure that diagnostic notes get emitted.
+    Diags.setLastDiagnosticIgnored(false);
+    generateCompilationDiagnostics(C, FailingCommand, AdditionalInformation,
+                                   GeneratedReport);
+  }
+
   /// @}
   /// @name Helper Methods
   /// @{
Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -1385,11 +1385,14 @@
   MarshallingInfoFlag<LangOpts<"EnableNewConstInterp">>;
 def fconstexpr_backtrace_limit_EQ : Joined<["-"], "fconstexpr-backtrace-limit=">,
                                     Group<f_Group>;
-def fno_crash_diagnostics : Flag<["-"], "fno-crash-diagnostics">, Group<f_clang_Group>, Flags<[NoArgumentUnused, CoreOption]>,
-  HelpText<"Disable auto-generation of preprocessed source files and a script for reproduction during a clang crash">;
 def fcrash_diagnostics_dir : Joined<["-"], "fcrash-diagnostics-dir=">,
   Group<f_clang_Group>, Flags<[NoArgumentUnused, CoreOption]>,
   HelpText<"Put crash-report files in <dir>">, MetaVarName<"<dir>">;
+def femit_reproducer : Joined<["-"], "femit-reproducer=">, Group<f_clang_Group>, Flags<[NoArgumentUnused, CoreOption]>,
+  HelpText<"Emit reproducer on (option: off, on-crash (default), on-error, always)">;
+def fno_crash_diagnostics : Flag<["-"], "fno-crash-diagnostics">, Group<f_clang_Group>, Flags<[NoArgumentUnused, CoreOption]>,
+  Alias<femit_reproducer>, AliasArgs<["off"]>,
+  HelpText<"Disable auto-generation of preprocessed source files and a script for reproduction during a clang crash">;
 def fcreate_profile : Flag<["-"], "fcreate-profile">, Group<f_Group>;
 defm cxx_exceptions: BoolFOption<"cxx-exceptions",
   LangOpts<"CXXExceptions">, DefaultFalse,
Index: clang/test/Driver/emit-reproducer.c
===================================================================
--- /dev/null
+++ clang/test/Driver/emit-reproducer.c
@@ -0,0 +1,33 @@
+// RUN: rm -rf %t; mkdir %t
+
+// RUN: not %clang -DFATAL %s -fcrash-diagnostics-dir=%t -femit-reproducer=off      2>&1 | FileCheck %s --check-prefix=NOT
+// RUN: not %clang -DFATAL %s -fcrash-diagnostics-dir=%t -fno-crash-diagnostics     2>&1 | FileCheck %s --check-prefix=NOT
+// RUN: not %clang -DFATAL %s -fcrash-diagnostics-dir=%t                            2>&1 | FileCheck %s
+// RUN: not %clang -DFATAL %s -fcrash-diagnostics-dir=%t -femit-reproducer=on-crash 2>&1 | FileCheck %s
+// RUN: not %clang -DFATAL %s -fcrash-diagnostics-dir=%t -femit-reproducer=on-error 2>&1 | FileCheck %s
+// RUN: not %clang -DFATAL %s -fcrash-diagnostics-dir=%t -femit-reproducer=always   2>&1 | FileCheck %s
+
+// RUN: not %clang -DERROR %s -fcrash-diagnostics-dir=%t -femit-reproducer=off      2>&1 | FileCheck %s --check-prefix=NOT
+// RUN: not %clang -DERROR %s -fcrash-diagnostics-dir=%t -fno-crash-diagnostics     2>&1 | FileCheck %s --check-prefix=NOT
+// RUN: not %clang -DERROR %s -fcrash-diagnostics-dir=%t                            2>&1 | FileCheck %s --check-prefix=NOT
+// RUN: not %clang -DERROR %s -fcrash-diagnostics-dir=%t -femit-reproducer=on-crash 2>&1 | FileCheck %s --check-prefix=NOT
+// RUN: not %clang -DERROR %s -fcrash-diagnostics-dir=%t -femit-reproducer=on-error 2>&1 | FileCheck %s
+// RUN: not %clang -DERROR %s -fcrash-diagnostics-dir=%t -femit-reproducer=always   2>&1 | FileCheck %s
+
+// RUN:     %clang         %s -fcrash-diagnostics-dir=%t -femit-reproducer=off      2>&1 | FileCheck %s --check-prefix=NOT --allow-empty
+// RUN:     %clang         %s -fcrash-diagnostics-dir=%t -fno-crash-diagnostics     2>&1 | FileCheck %s --check-prefix=NOT --allow-empty
+// RUN:     %clang         %s -fcrash-diagnostics-dir=%t                            2>&1 | FileCheck %s --check-prefix=NOT --allow-empty
+// RUN:     %clang         %s -fcrash-diagnostics-dir=%t -femit-reproducer=on-crash 2>&1 | FileCheck %s --check-prefix=NOT --allow-empty
+// RUN:     %clang         %s -fcrash-diagnostics-dir=%t -femit-reproducer=on-error 2>&1 | FileCheck %s --check-prefix=NOT --allow-empty
+// RUN:     %clang         %s -fcrash-diagnostics-dir=%t -femit-reproducer=always   2>&1 | FileCheck %s
+
+// CHECK:   note: diagnostic msg: {{.*}}emit-reproducer-{{.*}}.c
+// NOT-NOT: note: diagnostic msg: {{.*}}emit-reproducer-{{.*}}.c
+
+#ifdef FATAL
+#pragma clang __debug crash
+#elif ERROR
+int main
+#else
+int main() {}
+#endif
Index: clang/tools/driver/driver.cpp
===================================================================
--- clang/tools/driver/driver.cpp
+++ clang/tools/driver/driver.cpp
@@ -482,8 +482,21 @@
   }
 
   std::unique_ptr<Compilation> C(TheDriver.BuildCompilation(Args));
+
+  Driver::ReproLevel ReproLevel = Driver::ReproLevel::OnCrash;
+  if (Arg *A = C->getArgs().getLastArg(options::OPT_femit_reproducer))
+    ReproLevel = llvm::StringSwitch<Driver::ReproLevel>(A->getValue())
+                     .Case("off", Driver::ReproLevel::Off)
+                     .Case("on-crash", Driver::ReproLevel::OnCrash)
+                     .Case("on-error", Driver::ReproLevel::OnError)
+                     .Case("always", Driver::ReproLevel::Always)
+                     .Default(Driver::ReproLevel::OnCrash);
+
   int Res = 1;
   bool IsCrash = false;
+  Driver::CommandStatus CommandStatus = Driver::CommandStatus::Ok;
+  // Pretend the first command failed if ReproStatus is Always.
+  const Command *FailingCommand = &*C->getJobs().begin();
   if (C && !C->containsError()) {
     SmallVector<std::pair<int, const Command *>, 4> FailingCommands;
     Res = TheDriver.ExecuteCompilation(*C, FailingCommands);
@@ -507,7 +520,7 @@
 
     for (const auto &P : FailingCommands) {
       int CommandRes = P.first;
-      const Command *FailingCommand = P.second;
+      FailingCommand = P.second;
       if (!Res)
         Res = CommandRes;
 
@@ -526,13 +539,16 @@
       // https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xcu_chap02.html
       IsCrash |= CommandRes > 128;
 #endif
-      if (IsCrash) {
-        TheDriver.generateCompilationDiagnostics(*C, *FailingCommand);
+      CommandStatus =
+          IsCrash ? Driver::CommandStatus::Crash : Driver::CommandStatus::Error;
+      if (IsCrash)
         break;
-      }
     }
   }
 
+  TheDriver.generateCompilationDiagnosticsIfNecessary(CommandStatus, ReproLevel,
+                                                      *C, *FailingCommand);
+
   Diags.getClient()->finish();
 
   if (!UseNewCC1Process && IsCrash) {