Use LLVM's plugin registry to enable registering new compilation

databases. Move JSONCompilationDatabase.h to its own files and
register it as plugin.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162541 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 283 insertions, 0 deletions

diff --git a/lib/Tooling/JSONCompilationDatabase.cpp b/lib/Tooling/JSONCompilationDatabase.cpp
new file mode 100644
index 0000000000..c7cc38a31f
--- /dev/null
+++ b/lib/Tooling/JSONCompilationDatabase.cpp
@@ -0,0 +1,283 @@
+//===--- JSONCompilationDatabase.cpp - ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file contains the implementation of the JSONCompilationDatabase.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Tooling/JSONCompilationDatabase.h"
+
+#include "clang/Tooling/CompilationDatabase.h"
+#include "clang/Tooling/CompilationDatabasePluginRegistry.h"
+#include "clang/Tooling/Tooling.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/system_error.h"
+
+namespace clang {
+namespace tooling {
+
+namespace {
+
+/// \brief A parser for escaped strings of command line arguments.
+///
+/// Assumes \-escaping for quoted arguments (see the documentation of
+/// unescapeCommandLine(...)).
+class CommandLineArgumentParser {
+ public:
+  CommandLineArgumentParser(StringRef CommandLine)
+      : Input(CommandLine), Position(Input.begin()-1) {}
+
+  std::vector<std::string> parse() {
+    bool HasMoreInput = true;
+    while (HasMoreInput && nextNonWhitespace()) {
+      std::string Argument;
+      HasMoreInput = parseStringInto(Argument);
+      CommandLine.push_back(Argument);
+    }
+    return CommandLine;
+  }
+
+ private:
+  // All private methods return true if there is more input available.
+
+  bool parseStringInto(std::string &String) {
+    do {
+      if (*Position == '"') {
+        if (!parseQuotedStringInto(String)) return false;
+      } else {
+        if (!parseFreeStringInto(String)) return false;
+      }
+    } while (*Position != ' ');
+    return true;
+  }
+
+  bool parseQuotedStringInto(std::string &String) {
+    if (!next()) return false;
+    while (*Position != '"') {
+      if (!skipEscapeCharacter()) return false;
+      String.push_back(*Position);
+      if (!next()) return false;
+    }
+    return next();
+  }
+
+  bool parseFreeStringInto(std::string &String) {
+    do {
+      if (!skipEscapeCharacter()) return false;
+      String.push_back(*Position);
+      if (!next()) return false;
+    } while (*Position != ' ' && *Position != '"');
+    return true;
+  }
+
+  bool skipEscapeCharacter() {
+    if (*Position == '\\') {
+      return next();
+    }
+    return true;
+  }
+
+  bool nextNonWhitespace() {
+    do {
+      if (!next()) return false;
+    } while (*Position == ' ');
+    return true;
+  }
+
+  bool next() {
+    ++Position;
+    return Position != Input.end();
+  }
+
+  const StringRef Input;
+  StringRef::iterator Position;
+  std::vector<std::string> CommandLine;
+};
+
+std::vector<std::string> unescapeCommandLine(
+    StringRef EscapedCommandLine) {
+  CommandLineArgumentParser parser(EscapedCommandLine);
+  return parser.parse();
+}
+
+} // end namespace
+
+class JSONCompilationDatabasePlugin : public CompilationDatabasePlugin {
+  virtual CompilationDatabase *loadFromDirectory(
+      StringRef Directory, std::string &ErrorMessage) {
+    llvm::SmallString<1024> JSONDatabasePath(Directory);
+    llvm::sys::path::append(JSONDatabasePath, "compile_commands.json");
+    llvm::OwningPtr<CompilationDatabase> Database(
+        JSONCompilationDatabase::loadFromFile(JSONDatabasePath, ErrorMessage));
+    if (!Database)
+      return NULL;
+    return Database.take();
+  }
+};
+
+// Register the JSONCompilationDatabasePlugin with the
+// CompilationDatabasePluginRegistry using this statically initialized variable.
+static CompilationDatabasePluginRegistry::Add<JSONCompilationDatabasePlugin>
+X("json-compilation-database", "Reads JSON formatted compilation databases");
+
+// This anchor is used to force the linker to link in the generated object file
+// and thus register the JSONCompilationDatabasePlugin.
+int JSONAnchorSource = 0;
+
+JSONCompilationDatabase *
+JSONCompilationDatabase::loadFromFile(StringRef FilePath,
+                                      std::string &ErrorMessage) {
+  llvm::OwningPtr<llvm::MemoryBuffer> DatabaseBuffer;
+  llvm::error_code Result =
+    llvm::MemoryBuffer::getFile(FilePath, DatabaseBuffer);
+  if (Result != 0) {
+    ErrorMessage = "Error while opening JSON database: " + Result.message();
+    return NULL;
+  }
+  llvm::OwningPtr<JSONCompilationDatabase> Database(
+    new JSONCompilationDatabase(DatabaseBuffer.take()));
+  if (!Database->parse(ErrorMessage))
+    return NULL;
+  return Database.take();
+}
+
+JSONCompilationDatabase *
+JSONCompilationDatabase::loadFromBuffer(StringRef DatabaseString,
+                                        std::string &ErrorMessage) {
+  llvm::OwningPtr<llvm::MemoryBuffer> DatabaseBuffer(
+      llvm::MemoryBuffer::getMemBuffer(DatabaseString));
+  llvm::OwningPtr<JSONCompilationDatabase> Database(
+    new JSONCompilationDatabase(DatabaseBuffer.take()));
+  if (!Database->parse(ErrorMessage))
+    return NULL;
+  return Database.take();
+}
+
+std::vector<CompileCommand>
+JSONCompilationDatabase::getCompileCommands(StringRef FilePath) const {
+  llvm::SmallString<128> NativeFilePath;
+  llvm::sys::path::native(FilePath, NativeFilePath);
+  llvm::StringMap< std::vector<CompileCommandRef> >::const_iterator
+    CommandsRefI = IndexByFile.find(NativeFilePath);
+  if (CommandsRefI == IndexByFile.end())
+    return std::vector<CompileCommand>();
+  const std::vector<CompileCommandRef> &CommandsRef = CommandsRefI->getValue();
+  std::vector<CompileCommand> Commands;
+  for (int I = 0, E = CommandsRef.size(); I != E; ++I) {
+    llvm::SmallString<8> DirectoryStorage;
+    llvm::SmallString<1024> CommandStorage;
+    Commands.push_back(CompileCommand(
+      // FIXME: Escape correctly:
+      CommandsRef[I].first->getValue(DirectoryStorage),
+      unescapeCommandLine(CommandsRef[I].second->getValue(CommandStorage))));
+  }
+  return Commands;
+}
+
+std::vector<std::string>
+JSONCompilationDatabase::getAllFiles() const {
+  std::vector<std::string> Result;
+
+  llvm::StringMap< std::vector<CompileCommandRef> >::const_iterator
+    CommandsRefI = IndexByFile.begin();
+  const llvm::StringMap< std::vector<CompileCommandRef> >::const_iterator
+    CommandsRefEnd = IndexByFile.end();
+  for (; CommandsRefI != CommandsRefEnd; ++CommandsRefI) {
+    Result.push_back(CommandsRefI->first().str());
+  }
+
+  return Result;
+}
+
+bool JSONCompilationDatabase::parse(std::string &ErrorMessage) {
+  llvm::yaml::document_iterator I = YAMLStream.begin();
+  if (I == YAMLStream.end()) {
+    ErrorMessage = "Error while parsing YAML.";
+    return false;
+  }
+  llvm::yaml::Node *Root = I->getRoot();
+  if (Root == NULL) {
+    ErrorMessage = "Error while parsing YAML.";
+    return false;
+  }
+  llvm::yaml::SequenceNode *Array =
+    llvm::dyn_cast<llvm::yaml::SequenceNode>(Root);
+  if (Array == NULL) {
+    ErrorMessage = "Expected array.";
+    return false;
+  }
+  for (llvm::yaml::SequenceNode::iterator AI = Array->begin(),
+                                          AE = Array->end();
+       AI != AE; ++AI) {
+    llvm::yaml::MappingNode *Object =
+      llvm::dyn_cast<llvm::yaml::MappingNode>(&*AI);
+    if (Object == NULL) {
+      ErrorMessage = "Expected object.";
+      return false;
+    }
+    llvm::yaml::ScalarNode *Directory = NULL;
+    llvm::yaml::ScalarNode *Command = NULL;
+    llvm::yaml::ScalarNode *File = NULL;
+    for (llvm::yaml::MappingNode::iterator KVI = Object->begin(),
+                                           KVE = Object->end();
+         KVI != KVE; ++KVI) {
+      llvm::yaml::Node *Value = (*KVI).getValue();
+      if (Value == NULL) {
+        ErrorMessage = "Expected value.";
+        return false;
+      }
+      llvm::yaml::ScalarNode *ValueString =
+        llvm::dyn_cast<llvm::yaml::ScalarNode>(Value);
+      if (ValueString == NULL) {
+        ErrorMessage = "Expected string as value.";
+        return false;
+      }
+      llvm::yaml::ScalarNode *KeyString =
+        llvm::dyn_cast<llvm::yaml::ScalarNode>((*KVI).getKey());
+      if (KeyString == NULL) {
+        ErrorMessage = "Expected strings as key.";
+        return false;
+      }
+      llvm::SmallString<8> KeyStorage;
+      if (KeyString->getValue(KeyStorage) == "directory") {
+        Directory = ValueString;
+      } else if (KeyString->getValue(KeyStorage) == "command") {
+        Command = ValueString;
+      } else if (KeyString->getValue(KeyStorage) == "file") {
+        File = ValueString;
+      } else {
+        ErrorMessage = ("Unknown key: \"" +
+                        KeyString->getRawValue() + "\"").str();
+        return false;
+      }
+    }
+    if (!File) {
+      ErrorMessage = "Missing key: \"file\".";
+      return false;
+    }
+    if (!Command) {
+      ErrorMessage = "Missing key: \"command\".";
+      return false;
+    }
+    if (!Directory) {
+      ErrorMessage = "Missing key: \"directory\".";
+      return false;
+    }
+    llvm::SmallString<8> FileStorage;
+    llvm::SmallString<128> NativeFilePath;
+    llvm::sys::path::native(File->getValue(FileStorage), NativeFilePath);
+    IndexByFile[NativeFilePath].push_back(
+      CompileCommandRef(Directory, Command));
+  }
+  return true;
+}
+
+} // end namespace tooling
+} // end namespace clang