[code-complete] Introduce CodeCompletionTUInfo which will be used for caching

code-completion related strings specific to a translation unit (ASTContext and related data)

CodeCompletionAllocator does such limited caching, by caching the name assigned
to a DeclContext*, but that is not the appropriate place since that object has
a lifetime that can extend beyond that of an ASTContext.

Introduce CodeCompletionTUInfo which will be always tied to a translation unit
to do this kind of caching and move the caching of CodeCompletionAllocator into this
object, and propagate it to all the places where it will be needed.

The plan is to extend the caching where appropriate, using CodeCompletionTUInfo,
to avoid re-calculating code-completion strings.

Part of rdar://10796159.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@154408 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 63 insertions, 37 deletions

diff --git a/include/clang/Frontend/ASTUnit.h b/include/clang/Frontend/ASTUnit.h
index 3d0639561a..5b869a2136 100644
--- a/include/clang/Frontend/ASTUnit.h
+++ b/include/clang/Frontend/ASTUnit.h
@@ -58,14 +58,6 @@ class ASTFrontendAction;
 
 using namespace idx;
   
-/// \brief Allocator for a cached set of global code completions.
-class GlobalCodeCompletionAllocator 
-  : public CodeCompletionAllocator,
-    public RefCountedBase<GlobalCodeCompletionAllocator>
-{
-
-};
-  
 /// \brief Utility class for loading a ASTContext from an AST file.
 ///
 class ASTUnit : public ModuleLoader {
@@ -324,25 +316,20 @@ public:
   getCachedCompletionAllocator() {
     return CachedCompletionAllocator;
   }
-  
-  /// \brief Retrieve the allocator used to cache global code completions.
-  /// Creates the allocator if it doesn't already exist.
-  IntrusiveRefCntPtr<GlobalCodeCompletionAllocator>
-  getCursorCompletionAllocator() {
-    if (!CursorCompletionAllocator.getPtr()) {
-      CursorCompletionAllocator = new GlobalCodeCompletionAllocator;
-    }
-    return CursorCompletionAllocator;
+
+  CodeCompletionTUInfo &getCodeCompletionTUInfo() {
+    if (!CCTUInfo)
+      CCTUInfo.reset(new CodeCompletionTUInfo(
+                                            new GlobalCodeCompletionAllocator));
+    return *CCTUInfo;
   }
-  
+
 private:
   /// \brief Allocator used to store cached code completions.
   IntrusiveRefCntPtr<GlobalCodeCompletionAllocator>
     CachedCompletionAllocator;
   
-  /// \brief Allocator used to store code completions for arbitrary cursors.
-  IntrusiveRefCntPtr<GlobalCodeCompletionAllocator>
-    CursorCompletionAllocator;
+  OwningPtr<CodeCompletionTUInfo> CCTUInfo;
 
   /// \brief The set of cached code-completion results.
   std::vector<CachedCodeCompletionResult> CachedCompletionResults;
diff --git a/include/clang/Sema/CodeCompleteConsumer.h b/include/clang/Sema/CodeCompleteConsumer.h
index ff2ca871f2..fe9bed5c86 100644
--- a/include/clang/Sema/CodeCompleteConsumer.h
+++ b/include/clang/Sema/CodeCompleteConsumer.h
@@ -501,8 +501,6 @@ public:
 
 /// \brief An allocator used specifically for the purpose of code completion.
 class CodeCompletionAllocator : public llvm::BumpPtrAllocator {
-  llvm::DenseMap<DeclContext *, StringRef> ParentNames;
-  
 public:
   /// \brief Copy the given string into this allocator.
   const char *CopyString(StringRef String);
@@ -519,12 +517,34 @@ public:
   const char *CopyString(const std::string &String) {
     return CopyString(StringRef(String));
   }
-  
-  /// \brief Retrieve the mapping from known parent declaration contexts to
-  /// the (already copied) strings associated with each context.
-  llvm::DenseMap<DeclContext *, StringRef> &getParentNames() {
-    return ParentNames;
+};
+
+/// \brief Allocator for a cached set of global code completions.
+class GlobalCodeCompletionAllocator 
+  : public CodeCompletionAllocator,
+    public RefCountedBase<GlobalCodeCompletionAllocator>
+{
+
+};
+
+class CodeCompletionTUInfo {
+  llvm::DenseMap<DeclContext *, StringRef> ParentNames;
+  IntrusiveRefCntPtr<GlobalCodeCompletionAllocator> AllocatorRef;
+
+public:
+  explicit CodeCompletionTUInfo(
+                    IntrusiveRefCntPtr<GlobalCodeCompletionAllocator> Allocator)
+    : AllocatorRef(Allocator) { }
+
+  IntrusiveRefCntPtr<GlobalCodeCompletionAllocator> getAllocatorRef() const {
+    return AllocatorRef;
+  }
+  CodeCompletionAllocator &getAllocator() const {
+    assert(AllocatorRef);
+    return *AllocatorRef;
   }
+
+  StringRef getParentName(DeclContext *DC);
 };
 
 } // end namespace clang
@@ -544,6 +564,7 @@ public:
 
 private:
   CodeCompletionAllocator &Allocator;
+  CodeCompletionTUInfo &CCTUInfo;
   unsigned Priority;
   CXAvailabilityKind Availability;
   CXCursorKind ParentKind;
@@ -555,19 +576,25 @@ private:
   SmallVector<const char *, 2> Annotations;
 
 public:
-  CodeCompletionBuilder(CodeCompletionAllocator &Allocator)
-    : Allocator(Allocator), Priority(0), Availability(CXAvailability_Available),
+  CodeCompletionBuilder(CodeCompletionAllocator &Allocator,
+                        CodeCompletionTUInfo &CCTUInfo)
+    : Allocator(Allocator), CCTUInfo(CCTUInfo),
+      Priority(0), Availability(CXAvailability_Available),
       ParentKind(CXCursor_NotImplemented) { }
 
   CodeCompletionBuilder(CodeCompletionAllocator &Allocator,
+                        CodeCompletionTUInfo &CCTUInfo,
                         unsigned Priority, CXAvailabilityKind Availability)
-    : Allocator(Allocator), Priority(Priority), Availability(Availability),
+    : Allocator(Allocator), CCTUInfo(CCTUInfo),
+      Priority(Priority), Availability(Availability),
       ParentKind(CXCursor_NotImplemented) { }
 
   /// \brief Retrieve the allocator into which the code completion
   /// strings should be allocated.
   CodeCompletionAllocator &getAllocator() const { return Allocator; }
 
+  CodeCompletionTUInfo &getCodeCompletionTUInfo() const { return CCTUInfo; }
+
   /// \brief Take the resulting completion string.
   ///
   /// This operation can only be performed once.
@@ -753,10 +780,12 @@ public:
   /// \param Allocator The allocator that will be used to allocate the
   /// string itself.
   CodeCompletionString *CreateCodeCompletionString(Sema &S,
-                                           CodeCompletionAllocator &Allocator);
+                                           CodeCompletionAllocator &Allocator,
+                                           CodeCompletionTUInfo &CCTUInfo);
   CodeCompletionString *CreateCodeCompletionString(ASTContext &Ctx,
                                                    Preprocessor &PP,
-                                           CodeCompletionAllocator &Allocator);
+                                           CodeCompletionAllocator &Allocator,
+                                           CodeCompletionTUInfo &CCTUInfo);
 
   /// \brief Determine a base priority for the given declaration.
   static unsigned getPriorityFromDecl(NamedDecl *ND);
@@ -868,7 +897,8 @@ public:
     /// signature of this overload candidate.
     CodeCompletionString *CreateSignatureString(unsigned CurrentArg,
                                                 Sema &S,
-                                      CodeCompletionAllocator &Allocator) const;
+                                      CodeCompletionAllocator &Allocator,
+                                      CodeCompletionTUInfo &CCTUInfo) const;
   };
 
   CodeCompleteConsumer() : IncludeMacros(false), IncludeCodePatterns(false),
@@ -918,6 +948,8 @@ public:
   /// \brief Retrieve the allocator that will be used to allocate
   /// code completion strings.
   virtual CodeCompletionAllocator &getAllocator() = 0;
+
+  virtual CodeCompletionTUInfo &getCodeCompletionTUInfo() = 0;
 };
 
 /// \brief A simple code-completion consumer that prints the results it
@@ -926,7 +958,7 @@ class PrintingCodeCompleteConsumer : public CodeCompleteConsumer {
   /// \brief The raw output stream.
   raw_ostream &OS;
 
-  CodeCompletionAllocator Allocator;
+  CodeCompletionTUInfo CCTUInfo;
 
 public:
   /// \brief Create a new printing code-completion consumer that prints its
@@ -935,7 +967,8 @@ public:
                                bool IncludeGlobals,
                                raw_ostream &OS)
     : CodeCompleteConsumer(IncludeMacros, IncludeCodePatterns, IncludeGlobals,
-                           false), OS(OS) {}
+                           false), OS(OS),
+      CCTUInfo(new GlobalCodeCompletionAllocator) {}
 
   /// \brief Prints the finalized code-completion results.
   virtual void ProcessCodeCompleteResults(Sema &S,
@@ -947,7 +980,11 @@ public:
                                          OverloadCandidate *Candidates,
                                          unsigned NumCandidates);
 
-  virtual CodeCompletionAllocator &getAllocator() { return Allocator; }
+  virtual CodeCompletionAllocator &getAllocator() {
+    return CCTUInfo.getAllocator();
+  }
+
+  virtual CodeCompletionTUInfo &getCodeCompletionTUInfo() { return CCTUInfo; }
 };
 
 } // end namespace clang
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 674dd25604..31c410a9f9 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -78,6 +78,7 @@ namespace clang {
   class ClassTemplateSpecializationDecl;
   class CodeCompleteConsumer;
   class CodeCompletionAllocator;
+  class CodeCompletionTUInfo;
   class CodeCompletionResult;
   class Decl;
   class DeclAccessPair;
@@ -6647,6 +6648,7 @@ public:
                                              unsigned Argument);
   void CodeCompleteNaturalLanguage();
   void GatherGlobalCodeCompletions(CodeCompletionAllocator &Allocator,
+                                   CodeCompletionTUInfo &CCTUInfo,
                   SmallVectorImpl<CodeCompletionResult> &Results);
   //@}