Driver must return non-zero code on errors in command line

[sepavloff]

Summary

Now if clang driver is given wrong arguments, in some cases it
continues execution and returns zero code. This change fixes this
behavior.

The fix revealed some errors in clang test set.

File test/Driver/gfortran.f90 added in r118203 checks forwarding
gfortran flags to GCC. Now driver reports error on this file, because
the option -working-directory implemented in clang differs from the
option with the same name implemented in gfortran, in clang the option
requires argument, in gfortran does not.

In the file test/Driver/arm-darwin-builtin.c clang is called with
options -fbuiltin-strcat and -fbuiltin-strcpy. These option were removed
in r191435 and now clang reports error on this test.

File arm-default-build-attributes.s uses option -verify, which is not
supported by driver, it is cc1 option.

Similarly, the file split-debug.h uses options -fmodules-embed-all-files
and -fmodule-format=obj, which are not supported by driver.

Other revealed errors are mainly mistypes.

[rsmith]

Thank you, some of these test typos are ... alarming. =)

A couple of the test updates don't look quite right, but this mostly looks great.

test/Driver/amdgpu-features.c

1

This should say -o -

5

Likewise.

test/Driver/split-debug.h

5–6

These parts of the test don't make sense: the -fmodule-format=obj and -emit-module are -cc1 options, so testing how the driver deals with them doesn't really make a lot of sense. I would suggest deleting the highlighted region of this test rather than making it test the same thing three times.

[sepavloff]

Addressed reviewer's notes.

[rsmith]

LGTM

[sepavloff]

Added missed case

The patch missed a case when Compilation object is created during work of
clang based tool, it resulted in fail of the test 'clang-tidy/diagnostic.cpp'.
This addition to the patch add proper checks, hopefully, to all invocations of
'Driver::BuildCompilation'. Small changes are required in clang-tools-extra,
they are tracked by D33173.

[alexfh]

lib/Tooling/CompilationDatabase.cpp

210–212

This code is used as a library not only for command-line tools. Directly using stderr is wrong in many use cases of the Tooling library. It should instead somehow let the user of the library get these errors via a provided DiagnosticConsumer. Not sure how to do this here without a more careful reading of the code, but wanted to let you know that this change causes a regression at least for clang-tidy (and likely for many other Clang tools).

[sepavloff]

lib/Tooling/CompilationDatabase.cpp

210–212

This function does not have a way to report error, so its interface needs to be changed first. The change D33272 implements such modification.

[sepavloff]

Moved tooling related code into separate change D33272

include/clang/Tooling/CompilationDatabase.h

public:
   ///   cl::ParseCommandLineOptions(argc, argv);
   ///   ...
   /// }
   ///
   /// \param Argc The number of command line arguments - will be changed to
   /// the number of arguments before "--", if "--" was found in the argument
   /// list.
   /// \param Argv Points to the command line arguments.
+  /// \param ErrorMsg Contains error text if the function returns null pointer.
   /// \param Directory The base directory used in the FixedCompilationDatabase.
   static FixedCompilationDatabase *loadFromCommandLine(int &Argc,
                                                        const char *const *Argv,
+                                                       std::string &ErrorMsg,
                                                        Twine Directory = ".");
 
+  static FixedCompilationDatabase *loadFromCommandLine(int &Argc,
+                                                       const char *const *Argv,
+                                                       Twine Directory = ".") {
+    std::string ErrorMsg;
+    return loadFromCommandLine(Argc, Argv, ErrorMsg, Directory);
+  }
+
   /// \brief Constructs a compilation data base from a specified directory
   /// and command line.
   FixedCompilationDatabase(Twine Directory, ArrayRef<std::string> CommandLine);
 
   /// \brief Returns the given compile command.
   ///
   /// Will always return a vector with one entry that contains the directory
   /// and command line specified at construction with "clang-tool" as argv[0]

lib/Driver/Driver.cpp

Compilation *Driver::BuildCompilation(ArrayRef<const char *> ArgList) {
   ParseDriverMode(ClangExecutable, ArgList.slice(1));
 
   // FIXME: What are we going to do with -V and -b?
 
   // FIXME: This stuff needs to go into the Compilation, not the driver.
   bool CCCPrintPhases;
 
   InputArgList Args = ParseArgStrings(ArgList.slice(1));
+  if (Diags.hasErrorOccurred())
+    return nullptr;
 
   // Silence driver warnings if requested
   Diags.setIgnoreAllWarnings(Args.hasArg(options::OPT_w));
 
   // -no-canonical-prefixes is used very early in main.
   Args.ClaimAllArgs(options::OPT_no_canonical_prefixes);
 
   // Ignore -pipe.

lib/Frontend/CreateInvocationFromCommandLine.cpp

std::unique_ptr<CompilerInvocation> clang::createInvocationFromCommandLine(
   // FIXME: We shouldn't have to pass in the path info.
   driver::Driver TheDriver(Args[0], llvm::sys::getDefaultTargetTriple(),
                            *Diags);
 
   // Don't check that inputs exist, they may have been remapped.
   TheDriver.setCheckInputsExist(false);
 
   std::unique_ptr<driver::Compilation> C(TheDriver.BuildCompilation(Args));
+  if (!C)
+    return nullptr;
 
   // Just print the cc1 options if -### was present.
   if (C->getArgs().hasArg(driver::options::OPT__HASH_HASH_HASH)) {
     C->getJobs().Print(llvm::errs(), "\n", true);
     return nullptr;
   }
 
   // We expect to get back exactly one command job, if we didn't something

lib/Tooling/CommonOptionsParser.cpp

CommonOptionsParser::CommonOptionsParser(
 
   static cl::list<std::string> ArgsBefore(
       "extra-arg-before",
       cl::desc("Additional argument to prepend to the compiler command line"),
       cl::cat(Category));
 
   cl::HideUnrelatedOptions(Category);
 
-  Compilations.reset(FixedCompilationDatabase::loadFromCommandLine(argc, argv));
+  std::string ErrorMessage;
+  Compilations.reset(
+      FixedCompilationDatabase::loadFromCommandLine(argc, argv, ErrorMessage));
+  if (!Compilations) {
+    llvm::errs() << ErrorMessage;
+  }
   cl::ParseCommandLineOptions(argc, argv, Overview);
   cl::PrintOptionValues();
 
   SourcePathList = SourcePaths;
   if ((OccurrencesFlag == cl::ZeroOrMore || OccurrencesFlag == cl::Optional) &&
       SourcePathList.empty())
     return;
   if (!Compilations) {
-    std::string ErrorMessage;
     if (!BuildPath.empty()) {
       Compilations =
           CompilationDatabase::autoDetectFromDirectory(BuildPath, ErrorMessage);
     } else {
       Compilations = CompilationDatabase::autoDetectFromSource(SourcePaths[0],
                                                                ErrorMessage);
     }
     if (!Compilations) {

lib/Tooling/CompilationDatabase.cpp

 #include "clang/Driver/Job.h"
 #include "clang/Frontend/TextDiagnosticPrinter.h"
 #include "clang/Tooling/CompilationDatabasePluginRegistry.h"
 #include "clang/Tooling/Tooling.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
 #include <sstream>
 #include <system_error>
 using namespace clang;
 using namespace tooling;
 
 LLVM_INSTANTIATE_REGISTRY(CompilationDatabasePluginRegistry)
 
 CompilationDatabase::~CompilationDatabase() {}
private:
   }
 };
 
 // Special DiagnosticConsumer that looks for warn_drv_input_file_unused
 // diagnostics from the driver and collects the option strings for those unused
 // options.
 class UnusedInputDiagConsumer : public DiagnosticConsumer {
 public:
-  UnusedInputDiagConsumer() : Other(nullptr) {}
-
-  // Useful for debugging, chain diagnostics to another consumer after
-  // recording for our own purposes.
-  UnusedInputDiagConsumer(DiagnosticConsumer *Other) : Other(Other) {}
+  UnusedInputDiagConsumer(DiagnosticConsumer &Other) : Other(Other) {}
 
   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
                         const Diagnostic &Info) override {
     if (Info.getID() == clang::diag::warn_drv_input_file_unused) {
       // Arg 1 for this diagnostic is the option that didn't get used.
       UnusedInputs.push_back(Info.getArgStdStr(0));
-    }
-    if (Other)
-      Other->HandleDiagnostic(DiagLevel, Info);
+
+    // If driver failed to create compilation object, show the diagnostics
+    // to user.
+    } else if (DiagLevel >= DiagnosticsEngine::Error)
+      Other.HandleDiagnostic(DiagLevel, Info);
   }
 
-  DiagnosticConsumer *Other;
+  DiagnosticConsumer &Other;
   SmallVector<std::string, 2> UnusedInputs;
 };
 
 // Unary functor for asking "Given a StringRef S1, does there exist a string
 // S2 in Arr where S1 == S2?"
 struct MatchesAny {
   MatchesAny(ArrayRef<std::string> Arr) : Arr(Arr) {}
   bool operator() (StringRef S) {

 /// clear.
 ///
 /// \param[in] Args Args as provided by the user.
 /// \return Resulting stripped command line.
 ///          \li true if successful.
 ///          \li false if \c Args cannot be used for compilation jobs (e.g.
 ///          contains an option like -E or -version).
 static bool stripPositionalArgs(std::vector<const char *> Args,
-                                std::vector<std::string> &Result) {
+                                std::vector<std::string> &Result,
+                                std::string &ErrorMsg) {
   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
-  UnusedInputDiagConsumer DiagClient;
+  llvm::raw_string_ostream Output(ErrorMsg);
+  TextDiagnosticPrinter DiagnosticPrinter(Output, &*DiagOpts);
+  UnusedInputDiagConsumer DiagClient(DiagnosticPrinter);
   DiagnosticsEngine Diagnostics(
       IntrusiveRefCntPtr<clang::DiagnosticIDs>(new DiagnosticIDs()),
       &*DiagOpts, &DiagClient, false);
 
   // The clang executable path isn't required since the jobs the driver builds
   // will not be executed.
   std::unique_ptr<driver::Driver> NewDriver(new driver::Driver(
       /* ClangExecutable= */ "", llvm::sys::getDefaultTargetTriple(),
static bool stripPositionalArgs(std::vector<const char *> Args,
   // Remove -no-integrated-as; it's not used for syntax checking,
   // and it confuses targets which don't support this option.
   Args.erase(std::remove_if(Args.begin(), Args.end(),
                             MatchesAny(std::string("-no-integrated-as"))),
              Args.end());
 
   const std::unique_ptr<driver::Compilation> Compilation(
       NewDriver->BuildCompilation(Args));
+  if (!Compilation)
+    return false;
 
   const driver::JobList &Jobs = Compilation->getJobs();
 
   CompileJobAnalyzer CompileAnalyzer;
 
   for (const auto &Cmd : Jobs) {
     // Collect only for Assemble jobs. If we do all jobs we get duplicates
     // since Link jobs point to Assemble jobs as inputs.
     if (Cmd.getSource().getKind() == driver::Action::AssembleJobClass)
       CompileAnalyzer.run(&Cmd.getSource());
   }
 
   if (CompileAnalyzer.Inputs.empty()) {
-    // No compile jobs found.
-    // FIXME: Emit a warning of some kind?
+    ErrorMsg = "error: no compile jobs found\n";
     return false;
   }
 
   // Remove all compilation input files from the command line. This is
   // necessary so that getCompileCommands() can construct a command line for
   // each file.
   std::vector<const char *>::iterator End = std::remove_if(
       Args.begin(), Args.end(), MatchesAny(CompileAnalyzer.Inputs));
 
   // Remove all inputs deemed unused for compilation.
   End = std::remove_if(Args.begin(), End, MatchesAny(DiagClient.UnusedInputs));
 
   // Remove the -c add above as well. It will be at the end right now.
   assert(strcmp(*(End - 1), "-c") == 0);
   --End;
 
   Result = std::vector<std::string>(Args.begin() + 1, End);
   return true;
 }
 
 FixedCompilationDatabase *FixedCompilationDatabase::loadFromCommandLine(
-    int &Argc, const char *const *Argv, Twine Directory) {
+    int &Argc, const char *const *Argv, std::string &ErrorMsg,
+    Twine Directory) {
+  if (Argc == 0) {
+    ErrorMsg = "error: no arguments specified\n";
+    return nullptr;
+  }
   const char *const *DoubleDash = std::find(Argv, Argv + Argc, StringRef("--"));
-  if (DoubleDash == Argv + Argc)
+  if (DoubleDash == Argv + Argc) {
+    ErrorMsg = "error: double dash not found\n";
     return nullptr;
+  }
   std::vector<const char *> CommandLine(DoubleDash + 1, Argv + Argc);
   Argc = DoubleDash - Argv;
 
   std::vector<std::string> StrippedArgs;
-  if (!stripPositionalArgs(CommandLine, StrippedArgs))
+  if (!stripPositionalArgs(CommandLine, StrippedArgs, ErrorMsg))
     return nullptr;
   return new FixedCompilationDatabase(Directory, StrippedArgs);
 }
 
 FixedCompilationDatabase::
 FixedCompilationDatabase(Twine Directory, ArrayRef<std::string> CommandLine) {
   std::vector<std::string> ToolCommandLine(1, "clang-tool");
   ToolCommandLine.insert(ToolCommandLine.end(),

lib/Tooling/Tooling.cpp

DiagnosticsEngine Diagnostics(
       DiagConsumer ? DiagConsumer : &DiagnosticPrinter, false);
 
   const std::unique_ptr<clang::driver::Driver> Driver(
       newDriver(&Diagnostics, BinaryName, Files->getVirtualFileSystem()));
   // Since the input might only be virtual, don't check whether it exists.
   Driver->setCheckInputsExist(false);
   const std::unique_ptr<clang::driver::Compilation> Compilation(
       Driver->BuildCompilation(llvm::makeArrayRef(Argv)));
+  if (!Compilation)
+    return false;
   const llvm::opt::ArgStringList *const CC1Args = getCC1Arguments(
       &Diagnostics, Compilation.get());
   if (!CC1Args) {
     return false;
   }
   std::unique_ptr<clang::CompilerInvocation> Invocation(
       newInvocation(&Diagnostics, *CC1Args));
   // FIXME: remove this when all users have migrated!

test/Driver/aarch64-cpus.c

 // Check target CPUs are correctly passed.
 
 // RUN: %clang -target aarch64 -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
 // RUN: %clang -target aarch64 -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
 // RUN: %clang -target aarch64 -mlittle-endian -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
 // RUN: %clang -target aarch64 -mlittle-endian -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
 // RUN: %clang -target aarch64_be -mlittle-endian -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
 // RUN: %clang -target aarch64_be -mlittle-endian -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
 // GENERIC: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-cpu" "generic"
 
 // RUN: %clang -target arm64 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERIC %s
 // RUN: %clang -target arm64 -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERIC %s
 // RUN: %clang -target arm64 -mlittle-endian -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERIC %s
-// RUN: %clang -target arm64 -mlittle-endian -mcpu-generic -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERIC %s
+// RUN: %clang -target arm64 -mlittle-endian -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERIC %s
 
 // ARM64-GENERIC: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "generic"
 
 // RUN: %clang -target arm64-apple-darwin -arch arm64 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-DARWIN %s
 // ARM64-DARWIN: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "cyclone"
 
 // RUN: %clang -target aarch64 -mcpu=cortex-a35 -### -c %s 2>&1 | FileCheck -check-prefix=CA35 %s
 // RUN: %clang -target aarch64 -mlittle-endian -mcpu=cortex-a35 -### -c %s 2>&1 | FileCheck -check-prefix=CA35 %s

test/Driver/amdgpu-features.c

-// RUN: %clang -### -target amdgcn -x cl -S -emit-llvm -mcpu=kaveri -mamdgpu-debugger-abi=0.0 %s -o 2>&1 \
+// RUN: %clang -### -target amdgcn -x cl -S -emit-llvm -mcpu=kaveri -mamdgpu-debugger-abi=0.0 %s -o - 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-MAMDGPU-DEBUGGER-ABI-0-0 %s
 // CHECK-MAMDGPU-DEBUGGER-ABI-0-0: the clang compiler does not support '-mamdgpu-debugger-abi=0.0'
 
-// RUN: %clang -### -target amdgcn -x cl -S -emit-llvm -mcpu=kaveri -mamdgpu-debugger-abi=1.0 %s -o 2>&1 \
+// RUN: %clang -### -target amdgcn -x cl -S -emit-llvm -mcpu=kaveri -mamdgpu-debugger-abi=1.0 %s -o - 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-MAMDGPU-DEBUGGER-ABI-1-0 %s
 // CHECK-MAMDGPU-DEBUGGER-ABI-1-0: "-target-feature" "+amdgpu-debugger-insert-nops" "-target-feature" "+amdgpu-debugger-reserve-regs" "-target-feature" "+amdgpu-debugger-emit-prologue"

test/Driver/arm-darwin-builtin.c

-// FIXME: Disable pending PR4941.
-// RUX: clang -target x86_64-apple-darwin9 -arch arm -### -fsyntax-only %s 2> %t &&
-// RUX: grep -- "-fno-builtin-strcat" %t &&
-// RUX: grep -- "-fno-builtin-strcpy" %t &&
-
-// FIXME: Disable pending PR4941.
-// RUX: clang -target x86_64-apple-darwin9 -arch arm -### -fsyntax-only %s -fbuiltin-strcat -fbuiltin-strcpy 2> %t &&
-// RUX: not grep -- "-fno-builtin-strcat" %t &&
-// RUX: not grep -- "-fno-builtin-strcpy" %t &&
-
-// RUN: %clang -target x86_64-apple-darwin9 -arch arm -### -fsyntax-only %s -fbuiltin-strcat -fbuiltin-strcpy 2> %t
-// RUN: not grep -- "-fno-builtin-strcat" %t
-// RUN: not grep -- "-fno-builtin-strcpy" %t
-

test/Driver/arm-default-build-attributes.s

 // Enabled by default for assembly
 // RUN: %clang -target armv7--none-eabi -### %s 2>&1 \
 // RUN:    | FileCheck %s -check-prefix CHECK-ENABLED
 
 // Can be forced on or off for assembly.
 // RUN: %clang -target armv7--none-eabi -### %s 2>&1 -mno-default-build-attributes \
 // RUN:    | FileCheck %s -check-prefix CHECK-DISABLED
 // RUN: %clang -target armv7--none-eabi -### %s 2>&1 -mdefault-build-attributes \
 // RUN:    | FileCheck %s -check-prefix CHECK-ENABLED
 
 // Option ignored C/C++ (since we always emit hardware and ABI build attributes
 // during codegen).
-// RUN: %clang -target armv7--none-eabi -### -x c %s -mdefault-build-attributes -verify 2>&1 \
+// RUN: %clang -target armv7--none-eabi -### -x c %s -mdefault-build-attributes 2>&1 \
 // RUN:    | FileCheck %s -check-prefix CHECK-DISABLED
-// RUN: %clang -target armv7--none-eabi -### -x c++ %s -mdefault-build-attributes -verify 2>&1 \
+// RUN: %clang -target armv7--none-eabi -### -x c++ %s -mdefault-build-attributes 2>&1 \
 // RUN:    | FileCheck %s -check-prefix CHECK-DISABLED
 
 // CHECK-DISABLED-NOT: "-arm-add-build-attributes"
 // CHECK-ENABLED: "-arm-add-build-attributes"
 // expected-warning {{argument unused during compilation: '-mno-default-build-attributes'}}

test/Driver/cl-outputs.c

 // oDIRNAMEEXT2:  "-o" "foo.dir{{[/\\]+}}a.ext"
 
 // RUN: %clang_cl /c /o.. -### -- %s 2>&1 | FileCheck -check-prefix=oCRAZY1 %s
 // oCRAZY1:  "-o" "..obj"
 
 // RUN: %clang_cl /c /o .. -### -- %s 2>&1 | FileCheck -check-prefix=oCRAZY2 %s
 // oCRAZY2:  "-o" "..obj"
 
-// RUN: %clang_cl /c %s -### /o 2>&1 | FileCheck -check-prefix=oMISSINGARG %s
+// RUN: not %clang_cl /c %s -### /o 2>&1 | FileCheck -check-prefix=oMISSINGARG %s
 // oMISSINGARG: error: argument to '/o' is missing (expected 1 value)
 
 // RUN: %clang_cl /c /omydir/ -### -- %s %s 2>&1 | FileCheck -check-prefix=CHECK-oMULTIPLESOURCEOK1 %s
 // CHECK-oMULTIPLESOURCEOK1: "-o" "mydir{{[/\\]+}}cl-outputs.obj"
 
 // RUN: %clang_cl /c /o mydir/ -### -- %s %s 2>&1 | FileCheck -check-prefix=CHECK-oMULTIPLESOURCEOK2 %s
 // CHECK-oMULTIPLESOURCEOK2: "-o" "mydir{{[/\\]+}}cl-outputs.obj"
 

 // RUN: %clang_cl /o foo.dir/a.ext -### -- %s 2>&1 | FileCheck -check-prefix=FeoDIRNAMEEXT2 %s
 // FeoDIRNAMEEXT2: "-out:foo.dir{{[/\\]+}}a.ext"
 
 // RUN: %clang_cl /LD /o foo.dir/a.ext -### -- %s 2>&1 | FileCheck -check-prefix=FeoDIRNAMEEXTDLL %s
 // RUN: %clang_cl /LDd /ofoo.dir/a.ext -### -- %s 2>&1 | FileCheck -check-prefix=FeoDIRNAMEEXTDLL %s
 // FeoDIRNAMEEXTDLL: "-out:foo.dir{{[/\\]+}}a.ext"
 // FeoDIRNAMEEXTDLL: "-implib:foo.dir{{[/\\]+}}a.lib"
 
-// RUN: %clang_cl -### /o 2>&1 | FileCheck -check-prefix=FeoMISSINGARG %s
+// RUN: not %clang_cl -### /o 2>&1 | FileCheck -check-prefix=FeoMISSINGARG %s
 // FeoMISSINGARG: error: argument to '/o' is missing (expected 1 value)
 
 // RUN: %clang_cl /ofoo /o bar -### -- %s 2>&1 | FileCheck -check-prefix=FeoOVERRIDE %s
 // FeoOVERRIDE: "-out:bar.exe"
 
 
 // RUN: %clang_cl /FA -### -- %s 2>&1 | FileCheck -check-prefix=FA %s
 // FA: "-o" "cl-outputs.asm"

test/Driver/clang_f_opts.c

 // RUN: %clang -### -S -fslp-vectorize-aggressive %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE-AGG %s
 // RUN: %clang -### -S -fno-slp-vectorize-aggressive -fslp-vectorize-aggressive %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE-AGG %s
 // RUN: %clang -### -S -fno-slp-vectorize-aggressive %s 2>&1 | FileCheck -check-prefix=CHECK-NO-SLP-VECTORIZE-AGG %s
 // RUN: %clang -### -S -fslp-vectorize-aggressive -fno-slp-vectorize-aggressive %s 2>&1 | FileCheck -check-prefix=CHECK-NO-SLP-VECTORIZE-AGG %s
 // CHECK-SLP-VECTORIZE-AGG: "-vectorize-slp-aggressive"
 // CHECK-NO-SLP-VECTORIZE-AGG-NOT: "-vectorize-slp-aggressive"
 
 // RUN: %clang -### -S -fextended-identifiers %s 2>&1 | FileCheck -check-prefix=CHECK-EXTENDED-IDENTIFIERS %s
-// RUN: %clang -### -S -fno-extended-identifiers %s 2>&1 | FileCheck -check-prefix=CHECK-NO-EXTENDED-IDENTIFIERS %s
+// RUN: not %clang -### -S -fno-extended-identifiers %s 2>&1 | FileCheck -check-prefix=CHECK-NO-EXTENDED-IDENTIFIERS %s
 // CHECK-EXTENDED-IDENTIFIERS: "-cc1"
 // CHECK-EXTENDED-IDENTIFIERS-NOT: "-fextended-identifiers"
 // CHECK-NO-EXTENDED-IDENTIFIERS: error: unsupported option '-fno-extended-identifiers'
 
 // RUN: %clang -### -S -fno-pascal-strings -mpascal-strings %s 2>&1 | FileCheck -check-prefix=CHECK-M-PASCAL-STRINGS %s
 // CHECK-M-PASCAL-STRINGS: "-fpascal-strings"
 
 // RUN: %clang -### -S -fpascal-strings -mno-pascal-strings %s 2>&1 | FileCheck -check-prefix=CHECK-NO-M-PASCAL-STRINGS %s

test/Driver/cuda-external-tools.cu

 // RUN: %clang -### -target x86_64-linux-gnu -Ofast -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix ARCH64 -check-prefix SM20 -check-prefix OPT3 %s
 
 // With debugging enabled, ptxas should be run with with no ptxas optimizations.
 // RUN: %clang -### -target x86_64-linux-gnu --cuda-noopt-device-debug -O2 -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix ARCH64 -check-prefix SM20 -check-prefix DBG %s
 
 // --no-cuda-noopt-device-debug overrides --cuda-noopt-device-debug.
-// RUN: %clang -### -target x86_64-linux-gnu --cuda-noopt-debug \
-// RUN:   --no-cuda-noopt-debug -O2 -c %s 2>&1 \
+// RUN: %clang -### -target x86_64-linux-gnu --cuda-noopt-device-debug \
+// RUN:   --no-cuda-noopt-device-debug -O2 -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix ARCH64 -check-prefix SM20 -check-prefix OPT2 %s
 
 // Regular compile without -O.  This should result in us passing -O0 to ptxas.
 // RUN: %clang -### -target x86_64-linux-gnu -c %s 2>&1 \
 // RUN: | FileCheck -check-prefix ARCH64 -check-prefix SM20 -check-prefix OPT0 %s
 
 // Regular compiles with -Os and -Oz.  For lack of a better option, we map
 // these to ptxas -O3.

test/Driver/debug-options.c

 // RUN: %clang -### -c %s -g -target x86_64-scei-ps4 2>&1 \
 // RUN:             | FileCheck -check-prefix=NOCI %s
 // RUN: %clang -### -c %s -g -gcolumn-info -target x86_64-scei-ps4 2>&1 \
 // RUN:             | FileCheck -check-prefix=CI %s
 
 // RUN: %clang -### -c -gdwarf-2 %s 2>&1 \
 // RUN:             | FileCheck -check-prefix=G_ONLY_DWARF2 %s
 //
-// RUN: %clang -### -c -gfoo %s 2>&1 | FileCheck -check-prefix=G_NO %s
+// RUN: not %clang -### -c -gfoo %s 2>&1 | FileCheck -check-prefix=G_ERR %s
 // RUN: %clang -### -c -g -g0 %s 2>&1 | FileCheck -check-prefix=G_NO %s
 // RUN: %clang -### -c -ggdb0 %s 2>&1 | FileCheck -check-prefix=G_NO %s
 // RUN: %clang -### -c -glldb -g0 %s 2>&1 | FileCheck -check-prefix=G_NO %s
 // RUN: %clang -### -c -glldb -g1 %s 2>&1 \
 // RUN:             | FileCheck -check-prefix=GLTO_ONLY -check-prefix=G_LLDB %s
 //
 // PS4 defaults to sce; -ggdb0 changes tuning but turns off debug info,
 // then -g turns it back on without affecting tuning.

 // NOG_PS4-NOT "-dwarf-version=
 // NOG_PS4: "-generate-arange-section"
 // NOG_PS4-NOT: "-dwarf-version=
 //
 // G_PS4: "-cc1"
 // G_PS4: "-dwarf-version=
 // G_PS4: "-generate-arange-section"
 //
+// G_ERR: error: unknown argument:
+//
 // G_NO: "-cc1"
 // G_NO-NOT: -debug-info-kind=
 //
 // GLTO_ONLY: "-cc1"
 // GLTO_ONLY-NOT: "-dwarf-ext-refs"
 // GLTO_ONLY: "-debug-info-kind=line-tables-only"
 // GLTO_ONLY-NOT: "-dwarf-ext-refs"
 //

test/Driver/gfortran.f90

 ! RUN:     -frepack-arrays \
 ! RUN:     -fsecond-underscore \
 ! RUN:     -fshort-enums \
 ! RUN:     -fsign-zero \
 ! RUN:     -fstack-arrays \
 ! RUN:     -fsyntax-only \
 ! RUN:     -funderscoring \
 ! RUN:     -fwhole-file \
-! RUN:     -fworking-directory \
 ! RUN:     -imultilib \
 ! RUN:     -iprefix \
 ! RUN:     -iquote \
 ! RUN:     -isysroot \
 ! RUN:     -isystem \
 ! RUN:     -nocpp \
 ! RUN:     -nostdinc \
 ! RUN:     -pedantic \

 ! CHECK: "-frecursive"
 ! CHECK: "-frepack-arrays"
 ! CHECK: "-fsecond-underscore"
 ! CHECK: "-fshort-enums"
 ! CHECK: "-fsign-zero"
 ! CHECK: "-fstack-arrays"
 ! CHECK: "-funderscoring"
 ! CHECK: "-fwhole-file"
-! CHECK: "-fworking-directory"
 ! CHECK: "-imultilib"
 ! CHECK: "-iprefix"
 ! CHECK: "-iquote"
 ! CHECK: "-isysroot"
 ! CHECK: "-isystem"
 ! CHECK: "-nocpp"
 ! CHECK: "-nostdinc"
 ! CHECK: "-pedantic"

test/Driver/split-debug.h

 // Check that we aren't splitting debug output for modules builds that don't produce object files.
 //
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -c -fmodules -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-NO-ACTIONS < %t %s
 //
-// RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -c -fmodules -emit-module -fmodules-embed-all-files -fno-implicit-modules -fno-implicit-module-maps -### %s 2> %t
-// RUN: FileCheck -check-prefix=CHECK-NO-ACTIONS < %t %s
-//
-// FIXME: This should fail using clang, except that the type of the output for
-// an object output with modules is given as clang::driver::types::TY_PCH
-// rather than TY_Object.
-// RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -c -fmodules -fmodule-format=obj -### %s 2> %t
-// RUN: FileCheck -check-prefix=CHECK-NO-ACTIONS < %t %s
-//
 // CHECK-NO-ACTIONS-NOT: objcopy

test/Driver/unknown-arg.c

-// RUN: %clang %s -cake-is-lie -%0 -%d -HHHH -munknown-to-clang-option -print-stats -funknown-to-clang-option -### 2>&1 | \
+// RUN: not %clang %s -cake-is-lie -%0 -%d -HHHH -munknown-to-clang-option -print-stats -funknown-to-clang-option -### 2>&1 | \
 // RUN: FileCheck %s
 // RUN: %clang_cl -cake-is-lie -%0 -%d -HHHH -munknown-to-clang-option -print-stats -funknown-to-clang-option -### -c -- %s 2>&1 | \
 // RUN: FileCheck %s --check-prefix=CL
-// RUN: %clang_cl -cake-is-lie -%0 -%d -HHHH -munknown-to-clang-option -print-stats -funknown-to-clang-option -c -Werror=unknown-argument -### -- %s 2>&1 | \
+// RUN: not %clang_cl -cake-is-lie -%0 -%d -HHHH -munknown-to-clang-option -print-stats -funknown-to-clang-option -c -Werror=unknown-argument -### -- %s 2>&1 | \
 // RUN: FileCheck %s --check-prefix=CL-ERROR
 // RUN: %clang_cl -cake-is-lie -%0 -%d -HHHH -munknown-to-clang-option -print-stats -funknown-to-clang-option -c -Wno-unknown-argument -### -- %s 2>&1 | \
 // RUN: FileCheck %s --check-prefix=SILENT
 
 // CHECK: error: unknown argument: '-cake-is-lie'
 // CHECK: error: unknown argument: '-%0'
 // CHECK: error: unknown argument: '-%d'
 // CHECK: error: unknown argument: '-HHHH'

test/Index/index-attrs.c

-// RUN: c-index-test -index-file -check-prefix CHECK %s -target armv7-windows-gnu -fdeclspec
+// RUN: c-index-test -index-file %s -target armv7-windows-gnu -fdeclspec 2>&1 | FileCheck %s
 
 void __declspec(dllexport) export_function(void) {}
-// CHECK: [indexDeclaraton]: kind: function | name: export_function | {{.*}} | lang: C
+// CHECK: [indexDeclaration]: kind: function | name: export_function | {{.*}} | lang: C
 // CHECK: <attribute>: attribute(dllexport)
 void __attribute__((dllexport)) export_gnu_attribute(void) {}
-// CHECK: [indexDeclaration] kind: function | name: export_gnu_attribute | {{.*}} | lang: C
+// CHECK: [indexDeclaration]: kind: function | name: export_gnu_attribute | {{.*}} | lang: C
 // CHECK: <attribute>: attribute(dllexport)
 
 void __declspec(dllimport) import_function(void);
-// CHECK: [indexDeclaration] kind: function | name: import_function | {{.*}} | lang: C
+// CHECK: [indexDeclaration]: kind: function | name: import_function | {{.*}} | lang: C
 // CHECK: <attribute>: attribute(dllimport)
 void __attribute__((dllimport)) import_gnu_attribute(void);
-// CHECK: [indexDeclaration] kind: function | name: import_gnu_function | {{.*}} | lang: C
+// CHECK: [indexDeclaration]: kind: function | name: import_gnu_attribute | {{.*}} | lang: C
 // CHECK: <attribute>: attribute(dllimport)
 

test/Index/index-attrs.cpp

-// RUN: c-index-test -index-file -check-prefix CHECK %s -target armv7-windows-gnu -fdeclspec
+// RUN: c-index-test -index-file %s -target armv7-windows-gnu -fdeclspec | FileCheck %s
 
 struct __declspec(dllexport) export_s {
   void m();
 };
 // CHECK: [indexDeclaration]: kind: struct | name: export_s | {{.*}} | lang: C++
 // CHECK: <attribute>: attribute(dllexport)
 // CHECK: [indexDeclaration]: kind: c++-instance-method | name: m | {{.*}} | lang: C++
 // CHECK: <attribute>: attribute(dllexport)
 
 struct __declspec(dllimport) import_s {
   void m();
 };
 // CHECK: [indexDeclaration]: kind: struct | name: import_s | {{.*}} | lang: C++
 // CHECK: <attribute>: attribute(dllimport)
 // CHECK: [indexDeclaration]: kind: c++-instance-method | name: m | {{.*}} | lang: C++
 // CHECK: <attribute>: attribute(dllimport)
 
 class __attribute__((dllexport)) export_gnu_s {
   void m();
 };
-// CHECK: [indexDeclaration]: kind: struct | name: export_gnu_s | {{.*}} | lang: C++
+// CHECK: [indexDeclaration]: kind: c++-class | name: export_gnu_s | {{.*}} | lang: C++
 // CHECK: <attribute>: attribute(dllexport)
 // CHECK: [indexDeclaration]: kind: c++-instance-method | name: m | {{.*}} | lang: C++
 // CHECK: <attribute>: attribute(dllexport)
 
 class __attribute__((dllimport)) import_gnu_s {
   void m();
 };
-// CHECK: [indexDeclaration]: kind: struct | name: import_gnu_s | {{.*}} | lang: C++
+// CHECK: [indexDeclaration]: kind: c++-class | name: import_gnu_s | {{.*}} | lang: C++
 // CHECK: <attribute>: attribute(dllimport)
 // CHECK: [indexDeclaration]: kind: c++-instance-method | name: m | {{.*}} | lang: C++
 // CHECK: <attribute>: attribute(dllimport)
 
 extern "C" void __declspec(dllexport) export_function(void) {}
-// CHECK: [indexDeclaraton]: kind: function | name: export_function | {{.*}} | lang: C
+// CHECK: [indexDeclaration]: kind: function | name: export_function | {{.*}} | lang: C
 // CHECK: <attribute>: attribute(dllexport)
 extern "C" void __attribute__((dllexport)) export_gnu_function(void) {}
-// CHECK: [indexDeclaraton]: kind: function | name: export_gnu_function | {{.*}} | lang: C
+// CHECK: [indexDeclaration]: kind: function | name: export_gnu_function | {{.*}} | lang: C
 // CHECK: <attribute>: attribute(dllexport)
 
 extern "C" {
 void __declspec(dllimport) import_function(void);
-// CHECK: [indexDeclaration] kind: function | name: import_function | {{.*}} | lang: C
+// CHECK: [indexDeclaration]: kind: function | name: import_function | {{.*}} | lang: C
 // CHECK: <attribute>: attribute(dllimport)
 void __attribute__((dllimport)) import_gnu_function(void);
-// CHECK: [indexDeclaration] kind: function | name: import_gnu_function | {{.*}} | lang: C
+// CHECK: [indexDeclaration]: kind: function | name: import_gnu_function | {{.*}} | lang: C
 // CHECK: <attribute>: attribute(dllimport)
 }
 

tools/driver/driver.cpp

int main(int argc_, const char **argv_) {
   SetInstallDir(argv, TheDriver, CanonicalPrefixes);
 
   insertTargetAndModeArgs(TargetAndMode.first, TargetAndMode.second, argv,
                           SavedStrings);
 
   SetBackdoorDriverOutputsFromEnvVars(TheDriver);
 
   std::unique_ptr<Compilation> C(TheDriver.BuildCompilation(argv));
-  int Res = 0;
+  int Res = 1;
+  if (C.get()) {
     SmallVector<std::pair<int, const Command *>, 4> FailingCommands;
-  if (C.get())
     Res = TheDriver.ExecuteCompilation(*C, FailingCommands);
 
     // Force a crash to test the diagnostics.
     if (TheDriver.GenReproducer) {
       Diags.Report(diag::err_drv_force_crash)
         << !::getenv("FORCE_CLANG_DIAGNOSTICS_CRASH");
 
       // Pretend that every command failed.
       FailingCommands.clear();
       for (const auto &J : C->getJobs())
         if (const Command *C = dyn_cast<Command>(&J))
           FailingCommands.push_back(std::make_pair(-1, C));
     }
 
     for (const auto &P : FailingCommands) {
       int CommandRes = P.first;
       const Command *FailingCommand = P.second;
       if (!Res)
         Res = CommandRes;
 
       // If result status is < 0, then the driver command signalled an error.
       // If result status is 70, then the driver command reported a fatal error.
       // On Windows, abort will return an exit code of 3.  In these cases,
       // generate additional diagnostic information if possible.
       bool DiagnoseCrash = CommandRes < 0 || CommandRes == 70;
 #ifdef LLVM_ON_WIN32
       DiagnoseCrash |= CommandRes == 3;
 #endif
       if (DiagnoseCrash) {
         TheDriver.generateCompilationDiagnostics(*C, *FailingCommand);
         break;
       }
     }
+  }
 
   Diags.getClient()->finish();
 
   // If any timers were active but haven't been destroyed yet, print their
   // results now.  This happens in -disable-free mode.
   llvm::TimerGroup::printAll(llvm::errs());
 
 #ifdef LLVM_ON_WIN32

unittests/Driver/ToolChainTest.cpp

const char *EmptyFiles[] = {
       "/lib/arm-linux-gnueabihf/.keep"};
 
   for (const char *Path : EmptyFiles)
     InMemoryFileSystem->addFile(Path, 0,
                                 llvm::MemoryBuffer::getMemBuffer("\n"));
 
   std::unique_ptr<Compilation> C(TheDriver.BuildCompilation(
       {"-fsyntax-only", "--gcc-toolchain=", "foo.cpp"}));
+  EXPECT_TRUE(C);
 
   std::string S;
   {
     llvm::raw_string_ostream OS(S);
     C->getDefaultToolChain().printVerboseInfo(OS);
   }
 #if LLVM_ON_WIN32
   std::replace(S.begin(), S.end(), '\\', '/');
const char *EmptyFiles[] = {
       "/home/test/include/arm-linux-gnueabi/.keep"};
 
   for (const char *Path : EmptyFiles)
     InMemoryFileSystem->addFile(Path, 0,
                                 llvm::MemoryBuffer::getMemBuffer("\n"));
 
   std::unique_ptr<Compilation> C(TheDriver.BuildCompilation(
       {"-fsyntax-only", "--gcc-toolchain=", "foo.cpp"}));
+  EXPECT_TRUE(C);
 
   std::string S;
   {
     llvm::raw_string_ostream OS(S);
     C->getDefaultToolChain().printVerboseInfo(OS);
   }
 #if LLVM_ON_WIN32
   std::replace(S.begin(), S.end(), '\\', '/');
TEST(ToolChainTest, DefaultDriverMode) {
   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
   struct TestDiagnosticConsumer : public DiagnosticConsumer {};
   DiagnosticsEngine Diags(DiagID, &*DiagOpts, new TestDiagnosticConsumer);
   IntrusiveRefCntPtr<vfs::InMemoryFileSystem> InMemoryFileSystem(
       new vfs::InMemoryFileSystem);
 
   Driver CCDriver("/home/test/bin/clang", "arm-linux-gnueabi", Diags,
                   InMemoryFileSystem);
+  CCDriver.setCheckInputsExist(false);
   Driver CXXDriver("/home/test/bin/clang++", "arm-linux-gnueabi", Diags,
                    InMemoryFileSystem);
+  CXXDriver.setCheckInputsExist(false);
   Driver CLDriver("/home/test/bin/clang-cl", "arm-linux-gnueabi", Diags,
                   InMemoryFileSystem);
+  CLDriver.setCheckInputsExist(false);
 
-  std::unique_ptr<Compilation> CC(CCDriver.BuildCompilation({"foo.cpp"}));
-  std::unique_ptr<Compilation> CXX(CXXDriver.BuildCompilation({"foo.cpp"}));
-  std::unique_ptr<Compilation> CL(CLDriver.BuildCompilation({"foo.cpp"}));
-
+  std::unique_ptr<Compilation> CC(CCDriver.BuildCompilation(
+      { "/home/test/bin/clang", "foo.cpp"}));
+  std::unique_ptr<Compilation> CXX(CXXDriver.BuildCompilation(
+      { "/home/test/bin/clang++", "foo.cpp"}));
+  std::unique_ptr<Compilation> CL(CLDriver.BuildCompilation(
+      { "/home/test/bin/clang-cl", "foo.cpp"}));
+
+  EXPECT_TRUE(CC);
+  EXPECT_TRUE(CXX);
+  EXPECT_TRUE(CL);
   EXPECT_TRUE(CCDriver.CCCIsCC());
   EXPECT_TRUE(CXXDriver.CCCIsCXX());
   EXPECT_TRUE(CLDriver.IsCLMode());
 }
 
 } // end anonymous namespace.

unittests/Tooling/CompilationDatabaseTest.cpp

TEST(FixedCompilationDatabase, GetAllCompileCommands) {
   CommandLine.push_back("two");
   FixedCompilationDatabase Database(".", CommandLine);
 
   EXPECT_EQ(0ul, Database.getAllCompileCommands().size());
 }
 
 TEST(ParseFixedCompilationDatabase, ReturnsNullOnEmptyArgumentList) {
   int Argc = 0;
+  std::string ErrorMsg;
   std::unique_ptr<FixedCompilationDatabase> Database(
-      FixedCompilationDatabase::loadFromCommandLine(Argc, nullptr));
+      FixedCompilationDatabase::loadFromCommandLine(Argc, nullptr, ErrorMsg));
   EXPECT_FALSE(Database);
+  EXPECT_EQ(ErrorMsg, "error: no arguments specified\n");
   EXPECT_EQ(0, Argc);
 }
 
 TEST(ParseFixedCompilationDatabase, ReturnsNullWithoutDoubleDash) {
   int Argc = 2;
   const char *Argv[] = { "1", "2" };
+  std::string ErrorMsg;
   std::unique_ptr<FixedCompilationDatabase> Database(
-      FixedCompilationDatabase::loadFromCommandLine(Argc, Argv));
+      FixedCompilationDatabase::loadFromCommandLine(Argc, Argv, ErrorMsg));
   EXPECT_FALSE(Database);
+  EXPECT_EQ(ErrorMsg, "error: double dash not found\n");
   EXPECT_EQ(2, Argc);
 }
 
 TEST(ParseFixedCompilationDatabase, ReturnsArgumentsAfterDoubleDash) {
   int Argc = 5;
   const char *Argv[] = {
     "1", "2", "--\0no-constant-folding", "-DDEF3", "-DDEF4"
   };
+  std::string ErrorMsg;
   std::unique_ptr<FixedCompilationDatabase> Database(
-      FixedCompilationDatabase::loadFromCommandLine(Argc, Argv));
+      FixedCompilationDatabase::loadFromCommandLine(Argc, Argv, ErrorMsg));
   ASSERT_TRUE((bool)Database);
+  ASSERT_TRUE(ErrorMsg.empty());
   std::vector<CompileCommand> Result =
     Database->getCompileCommands("source");
   ASSERT_EQ(1ul, Result.size());
   ASSERT_EQ(".", Result[0].Directory);
   std::vector<std::string> CommandLine;
   CommandLine.push_back("clang-tool");
   CommandLine.push_back("-DDEF3");
   CommandLine.push_back("-DDEF4");
   CommandLine.push_back("source");
   ASSERT_EQ(CommandLine, Result[0].CommandLine);
   EXPECT_EQ(2, Argc);
 }
 
 TEST(ParseFixedCompilationDatabase, ReturnsEmptyCommandLine) {
   int Argc = 3;
   const char *Argv[] = { "1", "2", "--\0no-constant-folding" };
+  std::string ErrorMsg;
   std::unique_ptr<FixedCompilationDatabase> Database(
       FixedCompilationDatabase::loadFromCommandLine(Argc, Argv));
   ASSERT_TRUE((bool)Database);
+  ASSERT_TRUE(ErrorMsg.empty());
   std::vector<CompileCommand> Result =
     Database->getCompileCommands("source");
   ASSERT_EQ(1ul, Result.size());
   ASSERT_EQ(".", Result[0].Directory);
   std::vector<std::string> CommandLine;
   CommandLine.push_back("clang-tool");
   CommandLine.push_back("source");
   ASSERT_EQ(CommandLine, Result[0].CommandLine);
   EXPECT_EQ(2, Argc);
 }
 
 TEST(ParseFixedCompilationDatabase, HandlesPositionalArgs) {
   const char *Argv[] = {"1", "2", "--", "-c", "somefile.cpp", "-DDEF3"};
   int Argc = sizeof(Argv) / sizeof(char*);
+  std::string ErrorMsg;
   std::unique_ptr<FixedCompilationDatabase> Database(
       FixedCompilationDatabase::loadFromCommandLine(Argc, Argv));
   ASSERT_TRUE((bool)Database);
+  ASSERT_TRUE(ErrorMsg.empty());
   std::vector<CompileCommand> Result =
     Database->getCompileCommands("source");
   ASSERT_EQ(1ul, Result.size());
   ASSERT_EQ(".", Result[0].Directory);
   std::vector<std::string> Expected;
   Expected.push_back("clang-tool");
   Expected.push_back("-c");
   Expected.push_back("-DDEF3");
   Expected.push_back("source");
   ASSERT_EQ(Expected, Result[0].CommandLine);
   EXPECT_EQ(2, Argc);
 }
 
 TEST(ParseFixedCompilationDatabase, HandlesArgv0) {
   const char *Argv[] = {"1", "2", "--", "mytool", "somefile.cpp"};
   int Argc = sizeof(Argv) / sizeof(char*);
+  std::string ErrorMsg;
   std::unique_ptr<FixedCompilationDatabase> Database(
       FixedCompilationDatabase::loadFromCommandLine(Argc, Argv));
   ASSERT_TRUE((bool)Database);
+  ASSERT_TRUE(ErrorMsg.empty());
   std::vector<CompileCommand> Result =
     Database->getCompileCommands("source");
   ASSERT_EQ(1ul, Result.size());
   ASSERT_EQ(".", Result[0].Directory);
   std::vector<std::string> Expected;
   Expected.push_back("clang-tool");
   Expected.push_back("source");
   ASSERT_EQ(Expected, Result[0].CommandLine);
   EXPECT_EQ(2, Argc);
 }
 
 } // end namespace tooling
 } // end namespace clang