CompilationDatabase: Sure-up ownership of compilation databases using std::unique_ptr

Diving into the memory leaks fixed by r213851 there was one case of a
memory leak of a CompilationDatabase due to not properly taking
ownership of the result of "CompilationDatabase::autoDetectFromSource".
Given that both implementations and callers have been using unique_ptr
to own CompilationDatabase objects - make this explicit in the API to
reduce the risk of further leaks.

llvm-svn: 215215

1 files changed, 13 insertions, 14 deletions

diff --git a/clang/lib/Tooling/CompilationDatabase.cpp b/clang/lib/Tooling/CompilationDatabase.cpp
index 4b776bf..02bcf02 100644
--- a/clang/lib/Tooling/CompilationDatabase.cpp
+++ b/clang/lib/Tooling/CompilationDatabase.cpp
@@ -35,7 +35,7 @@ namespace tooling {
 
 CompilationDatabase::~CompilationDatabase() {}
 
-CompilationDatabase *
+std::unique_ptr<CompilationDatabase>
 CompilationDatabase::loadFromDirectory(StringRef BuildDirectory,
                                        std::string &ErrorMessage) {
   std::stringstream ErrorStream;
@@ -45,17 +45,16 @@ CompilationDatabase::loadFromDirectory(StringRef BuildDirectory,
        It != Ie; ++It) {
     std::string DatabaseErrorMessage;
     std::unique_ptr<CompilationDatabasePlugin> Plugin(It->instantiate());
-    if (CompilationDatabase *DB =
-        Plugin->loadFromDirectory(BuildDirectory, DatabaseErrorMessage))
+    if (std::unique_ptr<CompilationDatabase> DB =
+            Plugin->loadFromDirectory(BuildDirectory, DatabaseErrorMessage))
       return DB;
-    else
-      ErrorStream << It->getName() << ": " << DatabaseErrorMessage << "\n";
+    ErrorStream << It->getName() << ": " << DatabaseErrorMessage << "\n";
   }
   ErrorMessage = ErrorStream.str();
   return nullptr;
 }
 
-static CompilationDatabase *
+static std::unique_ptr<CompilationDatabase>
 findCompilationDatabaseFromDirectory(StringRef Directory,
                                      std::string &ErrorMessage) {
   std::stringstream ErrorStream;
@@ -63,8 +62,8 @@ findCompilationDatabaseFromDirectory(StringRef Directory,
   while (!Directory.empty()) {
     std::string LoadErrorMessage;
 
-    if (CompilationDatabase *DB =
-           CompilationDatabase::loadFromDirectory(Directory, LoadErrorMessage))
+    if (std::unique_ptr<CompilationDatabase> DB =
+            CompilationDatabase::loadFromDirectory(Directory, LoadErrorMessage))
       return DB;
 
     if (!HasErrorMessage) {
@@ -79,14 +78,14 @@ findCompilationDatabaseFromDirectory(StringRef Directory,
   return nullptr;
 }
 
-CompilationDatabase *
+std::unique_ptr<CompilationDatabase>
 CompilationDatabase::autoDetectFromSource(StringRef SourceFile,
                                           std::string &ErrorMessage) {
   SmallString<1024> AbsolutePath(getAbsolutePath(SourceFile));
   StringRef Directory = llvm::sys::path::parent_path(AbsolutePath);
 
-  CompilationDatabase *DB = findCompilationDatabaseFromDirectory(Directory,
-                                                                 ErrorMessage);
+  std::unique_ptr<CompilationDatabase> DB =
+      findCompilationDatabaseFromDirectory(Directory, ErrorMessage);
 
   if (!DB)
     ErrorMessage = ("Could not auto-detect compilation database for file \"" +
@@ -94,13 +93,13 @@ CompilationDatabase::autoDetectFromSource(StringRef SourceFile,
   return DB;
 }
 
-CompilationDatabase *
+std::unique_ptr<CompilationDatabase>
 CompilationDatabase::autoDetectFromDirectory(StringRef SourceDir,
                                              std::string &ErrorMessage) {
   SmallString<1024> AbsolutePath(getAbsolutePath(SourceDir));
 
-  CompilationDatabase *DB = findCompilationDatabaseFromDirectory(AbsolutePath,
-                                                                 ErrorMessage);
+  std::unique_ptr<CompilationDatabase> DB =
+      findCompilationDatabaseFromDirectory(AbsolutePath, ErrorMessage);
 
   if (!DB)
     ErrorMessage = ("Could not auto-detect compilation database from directory \"" +