Method loadFromCommandLine should be able to report errors

Now FixedCompilationDatabase::loadFromCommandLine has no means to report
which error occurred if it fails to create compilation object. This is
a block for implementing D33013, because after that change driver will
refuse to create compilation if command line contains erroneous options.

This change adds additional argument to loadFromCommandLine, which is
assigned error message text if compilation object was not created. This is
the same way as other methods of CompilationDatabase report failure.

Differential Revision: https://reviews.llvm.org/D33272

llvm-svn: 303741

6 files changed, 61 insertions, 31 deletions

diff --git a/clang/include/clang/Tooling/CompilationDatabase.h b/clang/include/clang/Tooling/CompilationDatabase.h
index 7f3f5869841..e988b84b6ea 100644
--- a/clang/include/clang/Tooling/CompilationDatabase.h
+++ b/clang/include/clang/Tooling/CompilationDatabase.h
@@ -176,10 +176,11 @@ public:
   /// 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,
-                                                       Twine Directory = ".");
+  static std::unique_ptr<FixedCompilationDatabase> loadFromCommandLine(
+      int &Argc, const char *const *Argv, std::string &ErrorMsg,
+      Twine Directory = ".");
 
   /// \brief Constructs a compilation data base from a specified directory
   /// and command line.
diff --git a/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp b/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp
index 16269064b6e..49d459e78c4 100644
--- a/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp
+++ b/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp
@@ -52,6 +52,8 @@ std::unique_ptr<CompilerInvocation> clang::createInvocationFromCommandLine(
   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)) {
diff --git a/clang/lib/Tooling/CommonOptionsParser.cpp b/clang/lib/Tooling/CommonOptionsParser.cpp
index 5a44061cbd4..9e9689e6b25 100644
--- a/clang/lib/Tooling/CommonOptionsParser.cpp
+++ b/clang/lib/Tooling/CommonOptionsParser.cpp
@@ -116,7 +116,11 @@ CommonOptionsParser::CommonOptionsParser(
 
   cl::HideUnrelatedOptions(Category);
 
-  Compilations.reset(FixedCompilationDatabase::loadFromCommandLine(argc, argv));
+  std::string ErrorMessage;
+  Compilations =
+      FixedCompilationDatabase::loadFromCommandLine(argc, argv, ErrorMessage);
+  if (!Compilations && !ErrorMessage.empty())
+    llvm::errs() << ErrorMessage;
   cl::ParseCommandLineOptions(argc, argv, Overview);
   cl::PrintOptionValues();
 
@@ -125,7 +129,6 @@ CommonOptionsParser::CommonOptionsParser(
       SourcePathList.empty())
     return;
   if (!Compilations) {
-    std::string ErrorMessage;
     if (!BuildPath.empty()) {
       Compilations =
           CompilationDatabase::autoDetectFromDirectory(BuildPath, ErrorMessage);
diff --git a/clang/lib/Tooling/CompilationDatabase.cpp b/clang/lib/Tooling/CompilationDatabase.cpp
index 8ca0b2df701..77c5b547ca0 100644
--- a/clang/lib/Tooling/CompilationDatabase.cpp
+++ b/clang/lib/Tooling/CompilationDatabase.cpp
@@ -27,6 +27,7 @@
 #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;
@@ -150,23 +151,21 @@ private:
 // 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));
+    } else if (DiagLevel >= DiagnosticsEngine::Error) {
+      // If driver failed to create compilation object, show the diagnostics
+      // to user.
+      Other.HandleDiagnostic(DiagLevel, Info);
     }
-    if (Other)
-      Other->HandleDiagnostic(DiagLevel, Info);
   }
 
-  DiagnosticConsumer *Other;
+  DiagnosticConsumer &Other;
   SmallVector<std::string, 2> UnusedInputs;
 };
 
@@ -205,9 +204,12 @@ private:
 ///          \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);
@@ -245,6 +247,8 @@ static bool stripPositionalArgs(std::vector<const char *> Args,
 
   const std::unique_ptr<driver::Compilation> Compilation(
       NewDriver->BuildCompilation(Args));
+  if (!Compilation)
+    return false;
 
   const driver::JobList &Jobs = Compilation->getJobs();
 
@@ -258,8 +262,7 @@ static bool stripPositionalArgs(std::vector<const char *> Args,
   }
 
   if (CompileAnalyzer.Inputs.empty()) {
-    // No compile jobs found.
-    // FIXME: Emit a warning of some kind?
+    ErrorMsg = "warning: no compile jobs found\n";
     return false;
   }
 
@@ -280,8 +283,14 @@ static bool stripPositionalArgs(std::vector<const char *> Args,
   return true;
 }
 
-FixedCompilationDatabase *FixedCompilationDatabase::loadFromCommandLine(
-    int &Argc, const char *const *Argv, Twine Directory) {
+std::unique_ptr<FixedCompilationDatabase>
+FixedCompilationDatabase::loadFromCommandLine(int &Argc,
+                                              const char *const *Argv,
+                                              std::string &ErrorMsg,
+                                              Twine Directory) {
+  ErrorMsg.clear();
+  if (Argc == 0)
+    return nullptr;
   const char *const *DoubleDash = std::find(Argv, Argv + Argc, StringRef("--"));
   if (DoubleDash == Argv + Argc)
     return nullptr;
@@ -289,9 +298,10 @@ FixedCompilationDatabase *FixedCompilationDatabase::loadFromCommandLine(
   Argc = DoubleDash - Argv;
 
   std::vector<std::string> StrippedArgs;
-  if (!stripPositionalArgs(CommandLine, StrippedArgs))
+  if (!stripPositionalArgs(CommandLine, StrippedArgs, ErrorMsg))
     return nullptr;
-  return new FixedCompilationDatabase(Directory, StrippedArgs);
+  return std::unique_ptr<FixedCompilationDatabase>(
+      new FixedCompilationDatabase(Directory, StrippedArgs));
 }
 
 FixedCompilationDatabase::
diff --git a/clang/lib/Tooling/Tooling.cpp b/clang/lib/Tooling/Tooling.cpp
index 9e1181281f1..2e093dd9afc 100644
--- a/clang/lib/Tooling/Tooling.cpp
+++ b/clang/lib/Tooling/Tooling.cpp
@@ -260,6 +260,8 @@ bool ToolInvocation::run() {
   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) {
diff --git a/clang/unittests/Tooling/CompilationDatabaseTest.cpp b/clang/unittests/Tooling/CompilationDatabaseTest.cpp
index 1a6fffec939..5a6693eb4db 100644
--- a/clang/unittests/Tooling/CompilationDatabaseTest.cpp
+++ b/clang/unittests/Tooling/CompilationDatabaseTest.cpp
@@ -504,18 +504,22 @@ TEST(FixedCompilationDatabase, GetAllCompileCommands) {
 
 TEST(ParseFixedCompilationDatabase, ReturnsNullOnEmptyArgumentList) {
   int Argc = 0;
-  std::unique_ptr<FixedCompilationDatabase> Database(
-      FixedCompilationDatabase::loadFromCommandLine(Argc, nullptr));
+  std::string ErrorMsg;
+  std::unique_ptr<FixedCompilationDatabase> Database =
+      FixedCompilationDatabase::loadFromCommandLine(Argc, nullptr, ErrorMsg);
   EXPECT_FALSE(Database);
+  EXPECT_TRUE(ErrorMsg.empty());
   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_TRUE(ErrorMsg.empty());
   EXPECT_EQ(2, Argc);
 }
 
@@ -524,9 +528,11 @@ TEST(ParseFixedCompilationDatabase, ReturnsArgumentsAfterDoubleDash) {
   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());
@@ -543,9 +549,11 @@ TEST(ParseFixedCompilationDatabase, ReturnsArgumentsAfterDoubleDash) {
 TEST(ParseFixedCompilationDatabase, ReturnsEmptyCommandLine) {
   int Argc = 3;
   const char *Argv[] = { "1", "2", "--\0no-constant-folding" };
-  std::unique_ptr<FixedCompilationDatabase> Database(
-      FixedCompilationDatabase::loadFromCommandLine(Argc, Argv));
+  std::string ErrorMsg;
+  std::unique_ptr<FixedCompilationDatabase> Database =
+      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());
@@ -560,9 +568,11 @@ TEST(ParseFixedCompilationDatabase, ReturnsEmptyCommandLine) {
 TEST(ParseFixedCompilationDatabase, HandlesPositionalArgs) {
   const char *Argv[] = {"1", "2", "--", "-c", "somefile.cpp", "-DDEF3"};
   int Argc = sizeof(Argv) / sizeof(char*);
-  std::unique_ptr<FixedCompilationDatabase> Database(
-      FixedCompilationDatabase::loadFromCommandLine(Argc, Argv));
+  std::string ErrorMsg;
+  std::unique_ptr<FixedCompilationDatabase> Database =
+      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());
@@ -579,9 +589,11 @@ TEST(ParseFixedCompilationDatabase, HandlesPositionalArgs) {
 TEST(ParseFixedCompilationDatabase, HandlesArgv0) {
   const char *Argv[] = {"1", "2", "--", "mytool", "somefile.cpp"};
   int Argc = sizeof(Argv) / sizeof(char*);
-  std::unique_ptr<FixedCompilationDatabase> Database(
-      FixedCompilationDatabase::loadFromCommandLine(Argc, Argv));
+  std::string ErrorMsg;
+  std::unique_ptr<FixedCompilationDatabase> Database =
+      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());