Introduce a new libclang aPI function,

clang_codeCompleteGetContexts(), that provides the client with
information about the context in which code completion has occurred
and what kinds of entities make sense as completions at that
point. Patch by Connor Wakamo!

llvm-svn: 134615

1 files changed, 192 insertions, 0 deletions

diff --git a/clang/tools/libclang/CIndexCodeCompletion.cpp b/clang/tools/libclang/CIndexCodeCompletion.cpp
index 0c8317e..832e2f2 100644
--- a/clang/tools/libclang/CIndexCodeCompletion.cpp
+++ b/clang/tools/libclang/CIndexCodeCompletion.cpp
@@ -235,6 +235,13 @@ struct AllocatedCXCodeCompleteResults : public CXCodeCompleteResults {
   
   /// \brief Allocator used to store code completion results.
   clang::CodeCompletionAllocator CodeCompletionAllocator;
+  
+  /// \brief Context under which completion occurred.
+  enum clang::CodeCompletionContext::Kind ContextKind;
+  
+  /// \brief A bitfield representing the acceptable completions for the
+  /// current context.
+  unsigned long long Contexts;
 };
 
 /// \brief Tracks the number of code-completion result objects that are 
@@ -273,6 +280,177 @@ AllocatedCXCodeCompleteResults::~AllocatedCXCodeCompleteResults() {
   
 } // end extern "C"
 
+static unsigned long long getContextsForContextKind(
+                                          enum CodeCompletionContext::Kind kind, 
+                                                    Sema &S) {
+  unsigned long long contexts = 0;
+  switch (kind) {
+    case CodeCompletionContext::CCC_OtherWithMacros: {
+      //We can allow macros here, but we don't know what else is permissible
+      //So we'll say the only thing permissible are macros
+      contexts = CXCompletionContext_MacroName;
+      break;
+    }
+    case CodeCompletionContext::CCC_TopLevel:
+    case CodeCompletionContext::CCC_ObjCIvarList:
+    case CodeCompletionContext::CCC_ClassStructUnion:
+    case CodeCompletionContext::CCC_Type: {
+      contexts = CXCompletionContext_AnyType | 
+                 CXCompletionContext_ObjCInterface;
+      if (S.getLangOptions().CPlusPlus) {
+        contexts |= CXCompletionContext_EnumTag |
+                    CXCompletionContext_UnionTag |
+                    CXCompletionContext_StructTag |
+                    CXCompletionContext_ClassTag |
+                    CXCompletionContext_NestedNameSpecifier;
+      }
+      break;
+    }
+    case CodeCompletionContext::CCC_Statement: {
+      contexts = CXCompletionContext_AnyType |
+                 CXCompletionContext_ObjCInterface |
+                 CXCompletionContext_AnyValue;
+      if (S.getLangOptions().CPlusPlus) {
+        contexts |= CXCompletionContext_EnumTag |
+                    CXCompletionContext_UnionTag |
+                    CXCompletionContext_StructTag |
+                    CXCompletionContext_ClassTag |
+                    CXCompletionContext_NestedNameSpecifier;
+      }
+      break;
+    }
+    case CodeCompletionContext::CCC_Expression: {
+      contexts = CXCompletionContext_AnyValue;
+      if (S.getLangOptions().CPlusPlus) {
+        contexts |= CXCompletionContext_AnyType |
+                    CXCompletionContext_ObjCInterface |
+                    CXCompletionContext_EnumTag |
+                    CXCompletionContext_UnionTag |
+                    CXCompletionContext_StructTag |
+                    CXCompletionContext_ClassTag |
+                    CXCompletionContext_NestedNameSpecifier;
+      }
+      break;
+    }
+    case CodeCompletionContext::CCC_ObjCMessageReceiver: {
+      contexts = CXCompletionContext_ObjCObjectValue |
+                 CXCompletionContext_ObjCSelectorValue |
+                 CXCompletionContext_ObjCInterface;
+      if (S.getLangOptions().CPlusPlus) {
+        contexts |= CXCompletionContext_CXXClassTypeValue |
+                    CXCompletionContext_AnyType |
+                    CXCompletionContext_EnumTag |
+                    CXCompletionContext_UnionTag |
+                    CXCompletionContext_StructTag |
+                    CXCompletionContext_ClassTag |
+                    CXCompletionContext_NestedNameSpecifier;
+      }
+      break;
+    }
+    case CodeCompletionContext::CCC_DotMemberAccess: {
+      contexts = CXCompletionContext_DotMemberAccess;
+      break;
+    }
+    case CodeCompletionContext::CCC_ArrowMemberAccess: {
+      contexts = CXCompletionContext_ArrowMemberAccess;
+      break;
+    }
+    case CodeCompletionContext::CCC_ObjCPropertyAccess: {
+      contexts = CXCompletionContext_ObjCPropertyAccess;
+      break;
+    }
+    case CodeCompletionContext::CCC_EnumTag: {
+      contexts = CXCompletionContext_EnumTag |
+                 CXCompletionContext_NestedNameSpecifier;
+      break;
+    }
+    case CodeCompletionContext::CCC_UnionTag: {
+      contexts = CXCompletionContext_UnionTag |
+                 CXCompletionContext_NestedNameSpecifier;
+      break;
+    }
+    case CodeCompletionContext::CCC_ClassOrStructTag: {
+      contexts = CXCompletionContext_StructTag |
+                 CXCompletionContext_ClassTag |
+                 CXCompletionContext_NestedNameSpecifier;
+      break;
+    }
+    case CodeCompletionContext::CCC_ObjCProtocolName: {
+      contexts = CXCompletionContext_ObjCProtocol;
+      break;
+    }
+    case CodeCompletionContext::CCC_Namespace: {
+      contexts = CXCompletionContext_Namespace;
+      break;
+    }
+    case CodeCompletionContext::CCC_PotentiallyQualifiedName: {
+      contexts = CXCompletionContext_NestedNameSpecifier;
+      break;
+    }
+    case CodeCompletionContext::CCC_MacroNameUse: {
+      contexts = CXCompletionContext_MacroName;
+      break;
+    }
+    case CodeCompletionContext::CCC_NaturalLanguage: {
+      contexts = CXCompletionContext_NaturalLanguage;
+      break;
+    }
+    case CodeCompletionContext::CCC_SelectorName: {
+      contexts = CXCompletionContext_ObjCSelectorName;
+      break;
+    }
+    case CodeCompletionContext::CCC_ParenthesizedExpression: {
+      contexts = CXCompletionContext_AnyType |
+                 CXCompletionContext_ObjCInterface |
+                 CXCompletionContext_AnyValue;
+      if (S.getLangOptions().CPlusPlus) {
+        contexts |= CXCompletionContext_EnumTag |
+                    CXCompletionContext_UnionTag |
+                    CXCompletionContext_StructTag |
+                    CXCompletionContext_ClassTag |
+                    CXCompletionContext_NestedNameSpecifier;
+      }
+      break;
+    }
+    case CodeCompletionContext::CCC_ObjCInstanceMessage: {
+      contexts = CXCompletionContext_ObjCInstanceMessage;
+      break;
+    }
+    case CodeCompletionContext::CCC_ObjCClassMessage: {
+      contexts = CXCompletionContext_ObjCClassMessage;
+      break;
+    }
+    case CodeCompletionContext::CCC_ObjCSuperclass: {
+      contexts = CXCompletionContext_ObjCInterface;
+      break;
+    }
+    case CodeCompletionContext::CCC_ObjCCategoryName: {
+      contexts = CXCompletionContext_ObjCCategory;
+      break;
+    }
+    case CodeCompletionContext::CCC_Other:
+    case CodeCompletionContext::CCC_ObjCInterface:
+    case CodeCompletionContext::CCC_ObjCImplementation:
+    case CodeCompletionContext::CCC_Name:
+    case CodeCompletionContext::CCC_MacroName:
+    case CodeCompletionContext::CCC_PreprocessorExpression:
+    case CodeCompletionContext::CCC_PreprocessorDirective:
+    case CodeCompletionContext::CCC_TypeQualifiers: {
+      //Only Clang results should be accepted, so we'll set all of the other
+      //context bits to 0 (i.e. the empty set)
+      contexts = CXCompletionContext_Unexposed;
+      break;
+    }
+    case CodeCompletionContext::CCC_Recovery: {
+      //We don't know what the current context is, so we'll return unknown
+      //This is the equivalent of setting all of the other context bits
+      contexts = CXCompletionContext_Unknown;
+      break;
+    }
+  }
+  return contexts;
+}
+
 namespace {
   class CaptureCompletionResults : public CodeCompleteConsumer {
     AllocatedCXCodeCompleteResults &AllocatedResults;
@@ -298,6 +476,11 @@ namespace {
         R.CompletionString = StoredCompletion;
         StoredResults.push_back(R);
       }
+      
+      enum CodeCompletionContext::Kind kind = Context.getKind();
+      
+      AllocatedResults.ContextKind = kind;
+      AllocatedResults.Contexts = getContextsForContextKind(kind, S);
     }
     
     virtual void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
@@ -538,6 +721,15 @@ clang_codeCompleteGetDiagnostic(CXCodeCompleteResults *ResultsIn,
   return new CXStoredDiagnostic(Results->Diagnostics[Index], Results->LangOpts);
 }
 
+unsigned long long
+clang_codeCompleteGetContexts(CXCodeCompleteResults *ResultsIn) {
+  AllocatedCXCodeCompleteResults *Results
+    = static_cast<AllocatedCXCodeCompleteResults*>(ResultsIn);
+  if (!Results)
+    return 0;
+  
+  return Results->Contexts;
+}
 
 } // end extern "C"