[Driver] Actually report errors during parsing instead of stopping when there's an error somewhere.

This is a more principled version of r303756. That change was both very
brittle about the state of the Diags object going into the driver and
also broke tooling in funny ways.

In particular it prevented tools from capturing diagnostics properly and
made the compilation database logic fail to provide arguments to the
tool, falling back to scanning directories for JSON files.

llvm-svn: 306822

6 files changed, 53 insertions, 18 deletions

diff --git a/clang/include/clang/Driver/Compilation.h b/clang/include/clang/Driver/Compilation.h
index 114e0b33c75..036b04605ac 100644
--- a/clang/include/clang/Driver/Compilation.h
+++ b/clang/include/clang/Driver/Compilation.h
@@ -105,10 +105,13 @@ class Compilation {
   /// Whether we're compiling for diagnostic purposes.
   bool ForDiagnostics;
 
+  /// Whether an error during the parsing of the input args.
+  bool ContainsError;
+
 public:
   Compilation(const Driver &D, const ToolChain &DefaultToolChain,
               llvm::opt::InputArgList *Args,
-              llvm::opt::DerivedArgList *TranslatedArgs);
+              llvm::opt::DerivedArgList *TranslatedArgs, bool ContainsError);
   ~Compilation();
 
   const Driver &getDriver() const { return TheDriver; }
@@ -275,6 +278,9 @@ public:
   /// Return true if we're compiling for diagnostics.
   bool isForDiagnostics() const { return ForDiagnostics; }
 
+  /// Return whether an error during the parsing of the input args.
+  bool containsError() const { return ContainsError; }
+
   /// Redirect - Redirect output of this compilation. Can only be done once.
   ///
   /// \param Redirects - array of pointers to paths. The array
diff --git a/clang/include/clang/Driver/Driver.h b/clang/include/clang/Driver/Driver.h
index 1009754a15d..5a087eea1b4 100644
--- a/clang/include/clang/Driver/Driver.h
+++ b/clang/include/clang/Driver/Driver.h
@@ -341,7 +341,8 @@ public:
 
   /// ParseArgStrings - Parse the given list of strings into an
   /// ArgList.
-  llvm::opt::InputArgList ParseArgStrings(ArrayRef<const char *> Args);
+  llvm::opt::InputArgList ParseArgStrings(ArrayRef<const char *> Args,
+                                          bool &ContainsError);
 
   /// BuildInputs - Construct the list of inputs and their types from 
   /// the given arguments.
diff --git a/clang/lib/Driver/Compilation.cpp b/clang/lib/Driver/Compilation.cpp
index 5c13e59a0d7..cf86644fb8c 100644
--- a/clang/lib/Driver/Compilation.cpp
+++ b/clang/lib/Driver/Compilation.cpp
@@ -23,10 +23,11 @@ using namespace clang;
 using namespace llvm::opt;
 
 Compilation::Compilation(const Driver &D, const ToolChain &_DefaultToolChain,
-                         InputArgList *_Args, DerivedArgList *_TranslatedArgs)
+                         InputArgList *_Args, DerivedArgList *_TranslatedArgs,
+                         bool ContainsError)
     : TheDriver(D), DefaultToolChain(_DefaultToolChain), ActiveOffloadMask(0u),
       Args(_Args), TranslatedArgs(_TranslatedArgs), Redirects(nullptr),
-      ForDiagnostics(false) {
+      ForDiagnostics(false), ContainsError(ContainsError) {
   // The offloading host toolchain is the default tool chain.
   OrderedOffloadingToolchains.insert(
       std::make_pair(Action::OFK_Host, &DefaultToolChain));
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index f23975829ea..faced0697ed 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -153,8 +153,10 @@ void Driver::setDriverModeFromOption(StringRef Opt) {
     Diag(diag::err_drv_unsupported_option_argument) << OptName << Value;
 }
 
-InputArgList Driver::ParseArgStrings(ArrayRef<const char *> ArgStrings) {
+InputArgList Driver::ParseArgStrings(ArrayRef<const char *> ArgStrings,
+                                     bool &ContainsError) {
   llvm::PrettyStackTraceString CrashInfo("Command line argument parsing");
+  ContainsError = false;
 
   unsigned IncludedFlagsBitmask;
   unsigned ExcludedFlagsBitmask;
@@ -167,27 +169,41 @@ InputArgList Driver::ParseArgStrings(ArrayRef<const char *> ArgStrings) {
                           IncludedFlagsBitmask, ExcludedFlagsBitmask);
 
   // Check for missing argument error.
-  if (MissingArgCount)
-    Diag(clang::diag::err_drv_missing_argument)
+  if (MissingArgCount) {
+    Diag(diag::err_drv_missing_argument)
         << Args.getArgString(MissingArgIndex) << MissingArgCount;
+    ContainsError |=
+        Diags.getDiagnosticLevel(diag::err_drv_missing_argument,
+                                 SourceLocation()) > DiagnosticsEngine::Warning;
+  }
 
   // Check for unsupported options.
   for (const Arg *A : Args) {
     if (A->getOption().hasFlag(options::Unsupported)) {
-      Diag(clang::diag::err_drv_unsupported_opt) << A->getAsString(Args);
+      Diag(diag::err_drv_unsupported_opt) << A->getAsString(Args);
+      ContainsError |= Diags.getDiagnosticLevel(diag::err_drv_unsupported_opt,
+                                                SourceLocation()) >
+                       DiagnosticsEngine::Warning;
       continue;
     }
 
     // Warn about -mcpu= without an argument.
     if (A->getOption().matches(options::OPT_mcpu_EQ) && A->containsValue("")) {
-      Diag(clang::diag::warn_drv_empty_joined_argument) << A->getAsString(Args);
+      Diag(diag::warn_drv_empty_joined_argument) << A->getAsString(Args);
+      ContainsError |= Diags.getDiagnosticLevel(
+                           diag::warn_drv_empty_joined_argument,
+                           SourceLocation()) > DiagnosticsEngine::Warning;
     }
   }
 
-  for (const Arg *A : Args.filtered(options::OPT_UNKNOWN))
-    Diags.Report(IsCLMode() ? diag::warn_drv_unknown_argument_clang_cl :
-                              diag::err_drv_unknown_argument)
-      << A->getAsString(Args);
+  for (const Arg *A : Args.filtered(options::OPT_UNKNOWN)) {
+    auto ID = IsCLMode() ? diag::warn_drv_unknown_argument_clang_cl
+                         : diag::err_drv_unknown_argument;
+
+    Diags.Report(ID) << A->getAsString(Args);
+    ContainsError |= Diags.getDiagnosticLevel(ID, SourceLocation()) >
+                     DiagnosticsEngine::Warning;
+  }
 
   return Args;
 }
@@ -600,9 +616,8 @@ Compilation *Driver::BuildCompilation(ArrayRef<const char *> ArgList) {
   // 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;
+  bool ContainsError;
+  InputArgList Args = ParseArgStrings(ArgList.slice(1), ContainsError);
 
   // Silence driver warnings if requested
   Diags.setIgnoreAllWarnings(Args.hasArg(options::OPT_w));
@@ -692,7 +707,8 @@ Compilation *Driver::BuildCompilation(ArrayRef<const char *> ArgList) {
       *UArgs, computeTargetTriple(*this, DefaultTargetTriple, *UArgs));
 
   // The compilation takes ownership of Args.
-  Compilation *C = new Compilation(*this, TC, UArgs.release(), TranslatedArgs);
+  Compilation *C = new Compilation(*this, TC, UArgs.release(), TranslatedArgs,
+                                   ContainsError);
 
   if (!HandleImmediateArgs(*C))
     return C;
diff --git a/clang/tools/driver/driver.cpp b/clang/tools/driver/driver.cpp
index af25d959802..9f37c428ff9 100644
--- a/clang/tools/driver/driver.cpp
+++ b/clang/tools/driver/driver.cpp
@@ -462,7 +462,7 @@ int main(int argc_, const char **argv_) {
 
   std::unique_ptr<Compilation> C(TheDriver.BuildCompilation(argv));
   int Res = 1;
-  if (C.get()) {
+  if (C && !C->containsError()) {
     SmallVector<std::pair<int, const Command *>, 4> FailingCommands;
     Res = TheDriver.ExecuteCompilation(*C, FailingCommands);
 
diff --git a/clang/unittests/Driver/ToolChainTest.cpp b/clang/unittests/Driver/ToolChainTest.cpp
index bce2748aa21..ec50560b202 100644
--- a/clang/unittests/Driver/ToolChainTest.cpp
+++ b/clang/unittests/Driver/ToolChainTest.cpp
@@ -152,5 +152,16 @@ TEST(ToolChainTest, DefaultDriverMode) {
   EXPECT_TRUE(CXXDriver.CCCIsCXX());
   EXPECT_TRUE(CLDriver.IsCLMode());
 }
+TEST(ToolChainTest, InvalidArgument) {
+  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
+  struct TestDiagnosticConsumer : public DiagnosticConsumer {};
+  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
+  DiagnosticsEngine Diags(DiagID, &*DiagOpts, new TestDiagnosticConsumer);
+  Driver TheDriver("/bin/clang", "arm-linux-gnueabihf", Diags);
+  std::unique_ptr<Compilation> C(TheDriver.BuildCompilation(
+      {"-fsyntax-only", "-fan-unknown-option", "foo.cpp"}));
+  EXPECT_TRUE(C);
+  EXPECT_TRUE(C->containsError());
+}
 
 } // end anonymous namespace.