[Basic] unique_ptr-ify SourceManager::MacroArgsCacheMap (NFC)

[jlebar]

The great thing about unique_ptr is, if it compiles, we're probably good. :)

[malcolm.parsons]

cfe/trunk/lib/Basic/SourceManager.cpp

1941

Redundant .get()

cfe/trunk/include/clang/Basic/SourceManager.h

class SourceManager : public RefCountedBase<SourceManager> {
   mutable std::unique_ptr<llvm::MemoryBuffer> FakeBufferForRecovery;
 
   mutable std::unique_ptr<SrcMgr::ContentCache> FakeContentCacheForRecovery;
 
   /// \brief Lazily computed map of macro argument chunks to their expanded
   /// source location.
   typedef std::map<unsigned, SourceLocation> MacroArgsMap;
 
-  mutable llvm::DenseMap<FileID, MacroArgsMap *> MacroArgsCacheMap;
+  mutable llvm::DenseMap<FileID, std::unique_ptr<MacroArgsMap>>
+      MacroArgsCacheMap;
 
   /// \brief The stack of modules being built, which is used to detect
   /// cycles in the module dependency graph as modules are being built, as
   /// well as to describe why we're rebuilding a particular module.
   ///
   /// There is no way to set this value from the command line. If we ever need
   /// to do so (e.g., if on-demand module construction moves out-of-process),
   /// we can add a cc1-level option to do so.
private:
   SourceLocation getSpellingLocSlowCase(SourceLocation Loc) const;
   SourceLocation getFileLocSlowCase(SourceLocation Loc) const;
 
   std::pair<FileID, unsigned>
   getDecomposedExpansionLocSlowCase(const SrcMgr::SLocEntry *E) const;
   std::pair<FileID, unsigned>
   getDecomposedSpellingLocSlowCase(const SrcMgr::SLocEntry *E,
                                    unsigned Offset) const;
-  void computeMacroArgsCache(MacroArgsMap *&MacroArgsCache, FileID FID) const;
+  void computeMacroArgsCache(MacroArgsMap &MacroArgsCache, FileID FID) const;
   void associateFileChunkWithMacroArgExp(MacroArgsMap &MacroArgsCache,
                                          FileID FID,
                                          SourceLocation SpellLoc,
                                          SourceLocation ExpansionLoc,
                                          unsigned ExpansionLength) const;
   friend class ASTReader;
   friend class ASTWriter;
 };

cfe/trunk/lib/Basic/SourceManager.cpp

SourceManager::~SourceManager() {
   }
   for (llvm::DenseMap<const FileEntry*, SrcMgr::ContentCache*>::iterator
        I = FileInfos.begin(), E = FileInfos.end(); I != E; ++I) {
     if (I->second) {
       I->second->~ContentCache();
       ContentCacheAlloc.Deallocate(I->second);
     }
   }
-
-  llvm::DeleteContainerSeconds(MacroArgsCacheMap);
 }
 
 void SourceManager::clearIDTables() {
   MainFileID = FileID();
   LocalSLocEntryTable.clear();
   LoadedSLocEntryTable.clear();
   SLocEntryLoaded.clear();
   LastLineNoFileIDQuery = FileID();

 
 /// \brief Compute a map of macro argument chunks to their expanded source
 /// location. Chunks that are not part of a macro argument will map to an
 /// invalid source location. e.g. if a file contains one macro argument at
 /// offset 100 with length 10, this is how the map will be formed:
 ///     0   -> SourceLocation()
 ///     100 -> Expanded macro arg location
 ///     110 -> SourceLocation()
-void SourceManager::computeMacroArgsCache(MacroArgsMap *&CachePtr,
+void SourceManager::computeMacroArgsCache(MacroArgsMap &MacroArgsCache,
                                           FileID FID) const {
   assert(FID.isValid());
-  assert(!CachePtr);
 
-  CachePtr = new MacroArgsMap();
-  MacroArgsMap &MacroArgsCache = *CachePtr;
   // Initially no macro argument chunk is present.
   MacroArgsCache.insert(std::make_pair(0, SourceLocation()));
 
   int ID = FID.ID;
   while (1) {
     ++ID;
     // Stop if there are no more FileIDs to check.
     if (ID > 0) {
if (Loc.isInvalid() || !Loc.isFileID())
     return Loc;
 
   FileID FID;
   unsigned Offset;
   std::tie(FID, Offset) = getDecomposedLoc(Loc);
   if (FID.isInvalid())
     return Loc;
 
-  MacroArgsMap *&MacroArgsCache = MacroArgsCacheMap[FID];
-  if (!MacroArgsCache)
-    computeMacroArgsCache(MacroArgsCache, FID);
+  std::unique_ptr<MacroArgsMap> &MacroArgsCache = MacroArgsCacheMap[FID];
+  if (!MacroArgsCache) {
+    MacroArgsCache = llvm::make_unique<MacroArgsMap>();
+    computeMacroArgsCache(*MacroArgsCache.get(), FID);
+  }
 
   assert(!MacroArgsCache->empty());
   MacroArgsMap::iterator I = MacroArgsCache->upper_bound(Offset);
   --I;
   
   unsigned MacroArgBeginOffs = I->first;
   SourceLocation MacroArgExpandedLoc = I->second;
   if (MacroArgExpandedLoc.isValid())