Index: clang-tools-extra/trunk/clang-tidy/tool/ClangTidyMain.cpp
===================================================================
--- clang-tools-extra/trunk/clang-tidy/tool/ClangTidyMain.cpp
+++ clang-tools-extra/trunk/clang-tidy/tool/ClangTidyMain.cpp
@@ -448,10 +448,9 @@
   runClangTidy(Context, OptionsParser.getCompilations(), PathList, BaseFS,
                EnableCheckProfile ? &Profile : nullptr);
   ArrayRef<ClangTidyError> Errors = Context.getErrors();
-  bool FoundErrors =
-      std::find_if(Errors.begin(), Errors.end(), [](const ClangTidyError &E) {
-        return E.DiagLevel == ClangTidyError::Error;
-      }) != Errors.end();
+  bool FoundErrors = llvm::find_if(Errors, [](const ClangTidyError &E) {
+                       return E.DiagLevel == ClangTidyError::Error;
+                     }) != Errors.end();
 
   const bool DisableFixes = Fix && FoundErrors && !FixErrors;
 
@@ -491,6 +490,19 @@
     return WErrorCount;
   }
 
+  if (FoundErrors) {
+    // TODO: Figure out when zero exit code should be used with -fix-errors:
+    //   a. when a fix has been applied for an error
+    //   b. when a fix has been applied for all errors
+    //   c. some other condition.
+    // For now always returning zero when -fix-errors is used.
+    if (FixErrors)
+      return 0;
+    if (!Quiet)
+      llvm::errs() << "Found compiler error(s).\n";
+    return 1;
+  }
+
   return 0;
 }
 
Index: clang-tools-extra/trunk/test/clang-tidy/bugprone-suspicious-semicolon-fail.cpp
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/bugprone-suspicious-semicolon-fail.cpp
+++ clang-tools-extra/trunk/test/clang-tidy/bugprone-suspicious-semicolon-fail.cpp
@@ -1,7 +1,9 @@
-// RUN: clang-tidy %s -checks="-*,bugprone-suspicious-semicolon" -- -DERROR 2>&1 \
+// RUN: not clang-tidy %s \
+// RUN:     -checks="-*,bugprone-suspicious-semicolon" -- -DERROR 2>&1 \
 // RUN:   | FileCheck %s -check-prefix=CHECK-ERROR \
 // RUN:       -implicit-check-not="{{warning|error}}:"
-// RUN: clang-tidy %s -checks="-*,bugprone-suspicious-semicolon,clang-diagnostic*" \
+// RUN: not clang-tidy %s \
+// RUN:     -checks="-*,bugprone-suspicious-semicolon,clang-diagnostic*" \
 // RUN:    -- -DWERROR -Wno-everything -Werror=unused-variable 2>&1 \
 // RUN:   | FileCheck %s -check-prefix=CHECK-WERROR \
 // RUN:       -implicit-check-not="{{warning|error}}:"
Index: clang-tools-extra/trunk/test/clang-tidy/check_clang_tidy.py
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/check_clang_tidy.py
+++ clang-tools-extra/trunk/test/clang-tidy/check_clang_tidy.py
@@ -39,6 +39,7 @@
 
 def main():
   parser = argparse.ArgumentParser()
+  parser.add_argument('-expect-clang-tidy-error', action='store_true')
   parser.add_argument('-resource-dir')
   parser.add_argument('-assume-filename')
   parser.add_argument('input_file_name')
@@ -52,6 +53,7 @@
   input_file_name = args.input_file_name
   check_name = args.check_name
   temp_file_name = args.temp_file_name
+  expect_clang_tidy_error = args.expect_clang_tidy_error
 
   file_name_with_extension = assume_file_name or input_file_name
   _, extension = os.path.splitext(file_name_with_extension)
@@ -97,6 +99,8 @@
 
   args = ['clang-tidy', temp_file_name, '-fix', '--checks=-*,' + check_name] + \
         clang_tidy_extra_args
+  if expect_clang_tidy_error:
+    args.insert(0, 'not')
   print('Running ' + repr(args) + '...')
   try:
     clang_tidy_output = \
Index: clang-tools-extra/trunk/test/clang-tidy/diagnostic.cpp
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/diagnostic.cpp
+++ clang-tools-extra/trunk/test/clang-tidy/diagnostic.cpp
@@ -1,13 +1,15 @@
-// RUN: clang-tidy -checks='-*,modernize-use-override' %s.nonexistent.cpp -- | FileCheck -check-prefix=CHECK1 -implicit-check-not='{{warning:|error:}}' %s
-// RUN: clang-tidy -checks='-*,clang-diagnostic-*,google-explicit-constructor' %s -- -fan-unknown-option | FileCheck -check-prefix=CHECK2 -implicit-check-not='{{warning:|error:}}' %s
-// RUN: clang-tidy -checks='-*,google-explicit-constructor,clang-diagnostic-literal-conversion' %s -- -fan-unknown-option | FileCheck -check-prefix=CHECK3 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,modernize-use-override' %s.nonexistent.cpp -- | FileCheck -check-prefix=CHECK1 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,clang-diagnostic-*,google-explicit-constructor' %s -- -fan-unknown-option | FileCheck -check-prefix=CHECK2 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,google-explicit-constructor,clang-diagnostic-literal-conversion' %s -- -fan-unknown-option | FileCheck -check-prefix=CHECK3 -implicit-check-not='{{warning:|error:}}' %s
 // RUN: clang-tidy -checks='-*,modernize-use-override,clang-diagnostic-macro-redefined' %s -- -DMACRO_FROM_COMMAND_LINE | FileCheck -check-prefix=CHECK4 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,modernize-use-override' %s -- -DCOMPILATION_ERROR | FileCheck -check-prefix=CHECK6 -implicit-check-not='{{warning:|error:}}' %s
 //
 // Now repeat the tests and ensure no other errors appear on stderr:
-// RUN: clang-tidy -checks='-*,modernize-use-override' %s.nonexistent.cpp -- 2>&1 | FileCheck -check-prefix=CHECK1 -implicit-check-not='{{warning:|error:}}' %s
-// RUN: clang-tidy -checks='-*,clang-diagnostic-*,google-explicit-constructor' %s -- -fan-unknown-option 2>&1 | FileCheck -check-prefix=CHECK2 -implicit-check-not='{{warning:|error:}}' %s
-// RUN: clang-tidy -checks='-*,google-explicit-constructor,clang-diagnostic-literal-conversion' %s -- -fan-unknown-option 2>&1 | FileCheck -check-prefix=CHECK3 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,modernize-use-override' %s.nonexistent.cpp -- 2>&1 | FileCheck -check-prefix=CHECK1 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,clang-diagnostic-*,google-explicit-constructor' %s -- -fan-unknown-option 2>&1 | FileCheck -check-prefix=CHECK2 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,google-explicit-constructor,clang-diagnostic-literal-conversion' %s -- -fan-unknown-option 2>&1 | FileCheck -check-prefix=CHECK3 -implicit-check-not='{{warning:|error:}}' %s
 // RUN: clang-tidy -checks='-*,modernize-use-override,clang-diagnostic-macro-redefined' %s -- -DMACRO_FROM_COMMAND_LINE 2>&1 | FileCheck -check-prefix=CHECK4 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,modernize-use-override' %s -- -DCOMPILATION_ERROR 2>&1 | FileCheck -check-prefix=CHECK6 -implicit-check-not='{{warning:|error:}}' %s
 //
 // Now create a directory with a compilation database file and ensure we don't
 // use it after failing to parse commands from the command line:
@@ -15,11 +17,12 @@
 // RUN: mkdir -p %T/diagnostics/
 // RUN: echo '[{"directory": "%/T/diagnostics/","command": "clang++ -fan-option-from-compilation-database -c %/T/diagnostics/input.cpp", "file": "%/T/diagnostics/input.cpp"}]' > %T/diagnostics/compile_commands.json
 // RUN: cat %s > %T/diagnostics/input.cpp
-// RUN: clang-tidy -checks='-*,modernize-use-override' %T/diagnostics/nonexistent.cpp -- 2>&1 | FileCheck -check-prefix=CHECK1 -implicit-check-not='{{warning:|error:}}' %s
-// RUN: clang-tidy -checks='-*,clang-diagnostic-*,google-explicit-constructor' %T/diagnostics/input.cpp -- -fan-unknown-option 2>&1 | FileCheck -check-prefix=CHECK2 -implicit-check-not='{{warning:|error:}}' %s
-// RUN: clang-tidy -checks='-*,google-explicit-constructor,clang-diagnostic-literal-conversion' %T/diagnostics/input.cpp -- -fan-unknown-option 2>&1 | FileCheck -check-prefix=CHECK3 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,modernize-use-override' %T/diagnostics/nonexistent.cpp -- 2>&1 | FileCheck -check-prefix=CHECK1 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,clang-diagnostic-*,google-explicit-constructor' %T/diagnostics/input.cpp -- -fan-unknown-option 2>&1 | FileCheck -check-prefix=CHECK2 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,google-explicit-constructor,clang-diagnostic-literal-conversion' %T/diagnostics/input.cpp -- -fan-unknown-option 2>&1 | FileCheck -check-prefix=CHECK3 -implicit-check-not='{{warning:|error:}}' %s
 // RUN: clang-tidy -checks='-*,modernize-use-override,clang-diagnostic-macro-redefined' %T/diagnostics/input.cpp -- -DMACRO_FROM_COMMAND_LINE 2>&1 | FileCheck -check-prefix=CHECK4 -implicit-check-not='{{warning:|error:}}' %s
-// RUN: clang-tidy -checks='-*,clang-diagnostic-*,google-explicit-constructor' %T/diagnostics/input.cpp 2>&1 | FileCheck -check-prefix=CHECK5 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,clang-diagnostic-*,google-explicit-constructor' %T/diagnostics/input.cpp 2>&1 | FileCheck -check-prefix=CHECK5 -implicit-check-not='{{warning:|error:}}' %s
+// RUN: not clang-tidy -checks='-*,modernize-use-override' %T/diagnostics/input.cpp -- -DCOMPILATION_ERROR 2>&1 | FileCheck -check-prefix=CHECK6 -implicit-check-not='{{warning:|error:}}' %s
 
 // CHECK1: error: error reading '{{.*}}nonexistent.cpp' [clang-diagnostic-error]
 // CHECK2: error: unknown argument: '-fan-unknown-option' [clang-diagnostic-error]
@@ -38,3 +41,10 @@
 
 #define MACRO_FROM_COMMAND_LINE
 // CHECK4: :[[@LINE-1]]:9: warning: 'MACRO_FROM_COMMAND_LINE' macro redefined
+
+#ifdef COMPILATION_ERROR
+void f(int a) {
+  &(a + 1);
+  // CHECK6: :[[@LINE-1]]:3: error: cannot take the address of an rvalue of type 'int' [clang-diagnostic-error]
+}
+#endif
Index: clang-tools-extra/trunk/test/clang-tidy/fix-errors.cpp
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/fix-errors.cpp
+++ clang-tools-extra/trunk/test/clang-tidy/fix-errors.cpp
@@ -1,5 +1,5 @@
 // RUN: grep -Ev "// *[A-Z-]+:" %s > %t.cpp
-// RUN: clang-tidy %t.cpp -checks='-*,google-explicit-constructor' -fix -- > %t.msg 2>&1
+// RUN: not clang-tidy %t.cpp -checks='-*,google-explicit-constructor' -fix -- > %t.msg 2>&1
 // RUN: FileCheck -input-file=%t.cpp -check-prefix=CHECK-FIX %s
 // RUN: FileCheck -input-file=%t.msg -check-prefix=CHECK-MESSAGES %s
 // RUN: grep -Ev "// *[A-Z-]+:" %s > %t.cpp
Index: clang-tools-extra/trunk/test/clang-tidy/misc-misplaced-const-cxx17.cpp
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/misc-misplaced-const-cxx17.cpp
+++ clang-tools-extra/trunk/test/clang-tidy/misc-misplaced-const-cxx17.cpp
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s misc-misplaced-const %t -- -- -std=c++17
+// RUN: %check_clang_tidy -expect-clang-tidy-error %s misc-misplaced-const %t -- -- -std=c++17
 
 // This test previously would cause a failed assertion because the structured
 // binding declaration had no valid type associated with it. This ensures the
Index: clang-tools-extra/trunk/test/clang-tidy/misc-unused-using-decls-errors.cpp
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/misc-unused-using-decls-errors.cpp
+++ clang-tools-extra/trunk/test/clang-tidy/misc-unused-using-decls-errors.cpp
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s misc-unused-using-decls %t
+// RUN: %check_clang_tidy -expect-clang-tidy-error %s misc-unused-using-decls %t
 
 namespace n {
 class C;
Index: clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-assert-failure.cpp
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-assert-failure.cpp
+++ clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-assert-failure.cpp
@@ -1,4 +1,4 @@
-// RUN: clang-tidy %s -checks=-*,modernize-loop-convert --
+// RUN: not clang-tidy %s -checks=-*,modernize-loop-convert --
 
 // Note: this test expects no assert failure happened in clang-tidy.
 
Index: clang-tools-extra/trunk/test/clang-tidy/readability-braces-around-statements-assert-failure.cpp
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/readability-braces-around-statements-assert-failure.cpp
+++ clang-tools-extra/trunk/test/clang-tidy/readability-braces-around-statements-assert-failure.cpp
@@ -1,4 +1,4 @@
-// RUN: clang-tidy -checks='-*,readability-braces-around-statements' %s --
+// RUN: not clang-tidy -checks='-*,readability-braces-around-statements' %s --
 
 // Note: this test expects no assert failure happened in clang-tidy.
 
Index: clang-tools-extra/trunk/test/clang-tidy/serialize-diagnostics.cpp
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/serialize-diagnostics.cpp
+++ clang-tools-extra/trunk/test/clang-tidy/serialize-diagnostics.cpp
@@ -1,3 +1,3 @@
-// RUN: clang-tidy -checks=-*,llvm-namespace-comment %s -- -serialize-diagnostics %t | FileCheck %s
+// RUN: not clang-tidy -checks=-*,llvm-namespace-comment %s -- -serialize-diagnostics %t | FileCheck %s
 // CHECK: :[[@LINE+1]]:12: error: expected ';' after struct [clang-diagnostic-error]
 struct A {}